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OpenCloudOS-Kernel/net/bridge/br_switchdev.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
// SPDX-License-Identifier: GPL-2.0
bridge: switchdev: Add forward mark support for stacked devices switchdev_port_fwd_mark_set() is used to set the 'offload_fwd_mark' of port netdevs so that packets being flooded by the device won't be flooded twice. It works by assigning a unique identifier (the ifindex of the first bridge port) to bridge ports sharing the same parent ID. This prevents packets from being flooded twice by the same switch, but will flood packets through bridge ports belonging to a different switch. This method is problematic when stacked devices are taken into account, such as VLANs. In such cases, a physical port netdev can have upper devices being members in two different bridges, thus requiring two different 'offload_fwd_mark's to be configured on the port netdev, which is impossible. The main problem is that packet and netdev marking is performed at the physical netdev level, whereas flooding occurs between bridge ports, which are not necessarily port netdevs. Instead, packet and netdev marking should really be done in the bridge driver with the switch driver only telling it which packets it already forwarded. The bridge driver will mark such packets using the mark assigned to the ingress bridge port and will prevent the packet from being forwarded through any bridge port sharing the same mark (i.e. having the same parent ID). Remove the current switchdev 'offload_fwd_mark' implementation and instead implement the proposed method. In addition, make rocker - the sole user of the mark - use the proposed method. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-26 00:42:37 +08:00
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <net/switchdev.h>
#include "br_private.h"
void nbp_switchdev_frame_mark(const struct net_bridge_port *p,
struct sk_buff *skb)
{
net: bridge: disambiguate offload_fwd_mark Before this change, four related - but distinct - concepts where named offload_fwd_mark: - skb->offload_fwd_mark: Set by the switchdev driver if the underlying hardware has already forwarded this frame to the other ports in the same hardware domain. - nbp->offload_fwd_mark: An idetifier used to group ports that share the same hardware forwarding domain. - br->offload_fwd_mark: Counter used to make sure that unique IDs are used in cases where a bridge contains ports from multiple hardware domains. - skb->cb->offload_fwd_mark: The hardware domain on which the frame ingressed and was forwarded. Introduce the term "hardware forwarding domain" ("hwdom") in the bridge to denote a set of ports with the following property: If an skb with skb->offload_fwd_mark set, is received on a port belonging to hwdom N, that frame has already been forwarded to all other ports in hwdom N. By decoupling the name from "offload_fwd_mark", we can extend the term's definition in the future - e.g. to add constraints that describe expected egress behavior - without overloading the meaning of "offload_fwd_mark". - nbp->offload_fwd_mark thus becomes nbp->hwdom. - br->offload_fwd_mark becomes br->last_hwdom. - skb->cb->offload_fwd_mark becomes skb->cb->src_hwdom. The slight change in naming here mandates a slight change in behavior of the nbp_switchdev_frame_mark() function. Previously, it only set this value in skb->cb for packets with skb->offload_fwd_mark true (ones which were forwarded in hardware). Whereas now we always track the incoming hwdom for all packets coming from a switchdev (even for the packets which weren't forwarded in hardware, such as STP BPDUs, IGMP reports etc). As all uses of skb->cb->offload_fwd_mark were already gated behind checks of skb->offload_fwd_mark, this will not introduce any functional change, but it paves the way for future changes where the ingressing hwdom must be known for frames coming from a switchdev regardless of whether they were forwarded in hardware or not (basically, if the skb comes from a switchdev, skb->cb->src_hwdom now always tracks which one). A typical example where this is relevant: the switchdev has a fixed configuration to trap STP BPDUs, but STP is not running on the bridge and the group_fwd_mask allows them to be forwarded. Say we have this setup: br0 / | \ / | \ swp0 swp1 swp2 A BPDU comes in on swp0 and is trapped to the CPU; the driver does not set skb->offload_fwd_mark. The bridge determines that the frame should be forwarded to swp{1,2}. It is imperative that forward offloading is _not_ allowed in this case, as the source hwdom is already "poisoned". Recording the source hwdom allows this case to be handled properly. v2->v3: added code comments v3->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:23:59 +08:00
if (p->hwdom)
BR_INPUT_SKB_CB(skb)->src_hwdom = p->hwdom;
bridge: switchdev: Add forward mark support for stacked devices switchdev_port_fwd_mark_set() is used to set the 'offload_fwd_mark' of port netdevs so that packets being flooded by the device won't be flooded twice. It works by assigning a unique identifier (the ifindex of the first bridge port) to bridge ports sharing the same parent ID. This prevents packets from being flooded twice by the same switch, but will flood packets through bridge ports belonging to a different switch. This method is problematic when stacked devices are taken into account, such as VLANs. In such cases, a physical port netdev can have upper devices being members in two different bridges, thus requiring two different 'offload_fwd_mark's to be configured on the port netdev, which is impossible. The main problem is that packet and netdev marking is performed at the physical netdev level, whereas flooding occurs between bridge ports, which are not necessarily port netdevs. Instead, packet and netdev marking should really be done in the bridge driver with the switch driver only telling it which packets it already forwarded. The bridge driver will mark such packets using the mark assigned to the ingress bridge port and will prevent the packet from being forwarded through any bridge port sharing the same mark (i.e. having the same parent ID). Remove the current switchdev 'offload_fwd_mark' implementation and instead implement the proposed method. In addition, make rocker - the sole user of the mark - use the proposed method. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-26 00:42:37 +08:00
}
bool nbp_switchdev_allowed_egress(const struct net_bridge_port *p,
const struct sk_buff *skb)
{
return !skb->offload_fwd_mark ||
net: bridge: disambiguate offload_fwd_mark Before this change, four related - but distinct - concepts where named offload_fwd_mark: - skb->offload_fwd_mark: Set by the switchdev driver if the underlying hardware has already forwarded this frame to the other ports in the same hardware domain. - nbp->offload_fwd_mark: An idetifier used to group ports that share the same hardware forwarding domain. - br->offload_fwd_mark: Counter used to make sure that unique IDs are used in cases where a bridge contains ports from multiple hardware domains. - skb->cb->offload_fwd_mark: The hardware domain on which the frame ingressed and was forwarded. Introduce the term "hardware forwarding domain" ("hwdom") in the bridge to denote a set of ports with the following property: If an skb with skb->offload_fwd_mark set, is received on a port belonging to hwdom N, that frame has already been forwarded to all other ports in hwdom N. By decoupling the name from "offload_fwd_mark", we can extend the term's definition in the future - e.g. to add constraints that describe expected egress behavior - without overloading the meaning of "offload_fwd_mark". - nbp->offload_fwd_mark thus becomes nbp->hwdom. - br->offload_fwd_mark becomes br->last_hwdom. - skb->cb->offload_fwd_mark becomes skb->cb->src_hwdom. The slight change in naming here mandates a slight change in behavior of the nbp_switchdev_frame_mark() function. Previously, it only set this value in skb->cb for packets with skb->offload_fwd_mark true (ones which were forwarded in hardware). Whereas now we always track the incoming hwdom for all packets coming from a switchdev (even for the packets which weren't forwarded in hardware, such as STP BPDUs, IGMP reports etc). As all uses of skb->cb->offload_fwd_mark were already gated behind checks of skb->offload_fwd_mark, this will not introduce any functional change, but it paves the way for future changes where the ingressing hwdom must be known for frames coming from a switchdev regardless of whether they were forwarded in hardware or not (basically, if the skb comes from a switchdev, skb->cb->src_hwdom now always tracks which one). A typical example where this is relevant: the switchdev has a fixed configuration to trap STP BPDUs, but STP is not running on the bridge and the group_fwd_mask allows them to be forwarded. Say we have this setup: br0 / | \ / | \ swp0 swp1 swp2 A BPDU comes in on swp0 and is trapped to the CPU; the driver does not set skb->offload_fwd_mark. The bridge determines that the frame should be forwarded to swp{1,2}. It is imperative that forward offloading is _not_ allowed in this case, as the source hwdom is already "poisoned". Recording the source hwdom allows this case to be handled properly. v2->v3: added code comments v3->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:23:59 +08:00
BR_INPUT_SKB_CB(skb)->src_hwdom != p->hwdom;
bridge: switchdev: Add forward mark support for stacked devices switchdev_port_fwd_mark_set() is used to set the 'offload_fwd_mark' of port netdevs so that packets being flooded by the device won't be flooded twice. It works by assigning a unique identifier (the ifindex of the first bridge port) to bridge ports sharing the same parent ID. This prevents packets from being flooded twice by the same switch, but will flood packets through bridge ports belonging to a different switch. This method is problematic when stacked devices are taken into account, such as VLANs. In such cases, a physical port netdev can have upper devices being members in two different bridges, thus requiring two different 'offload_fwd_mark's to be configured on the port netdev, which is impossible. The main problem is that packet and netdev marking is performed at the physical netdev level, whereas flooding occurs between bridge ports, which are not necessarily port netdevs. Instead, packet and netdev marking should really be done in the bridge driver with the switch driver only telling it which packets it already forwarded. The bridge driver will mark such packets using the mark assigned to the ingress bridge port and will prevent the packet from being forwarded through any bridge port sharing the same mark (i.e. having the same parent ID). Remove the current switchdev 'offload_fwd_mark' implementation and instead implement the proposed method. In addition, make rocker - the sole user of the mark - use the proposed method. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-26 00:42:37 +08:00
}
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
/* Flags that can be offloaded to hardware */
#define BR_PORT_FLAGS_HW_OFFLOAD (BR_LEARNING | BR_FLOOD | \
BR_MCAST_FLOOD | BR_BCAST_FLOOD)
int br_switchdev_set_port_flag(struct net_bridge_port *p,
unsigned long flags,
net: bridge: don't print in br_switchdev_set_port_flag For the netlink interface, propagate errors through extack rather than simply printing them to the console. For the sysfs interface, we still print to the console, but at least that's one layer higher than in switchdev, which also allows us to silently ignore the offloading of flags if that is ever needed in the future. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 23:15:53 +08:00
unsigned long mask,
struct netlink_ext_ack *extack)
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
{
struct switchdev_attr attr = {
.orig_dev = p->dev,
};
net: switchdev: Replace port attr set SDO with a notification Drop switchdev_ops.switchdev_port_attr_set. Drop the uses of this field from all clients, which were migrated to use switchdev notification in the previous patches. Add a new function switchdev_port_attr_notify() that sends the switchdev notifications SWITCHDEV_PORT_ATTR_SET and calls the blocking (process) notifier chain. We have one odd case within net/bridge/br_switchdev.c with the SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS attribute identifier that requires executing from atomic context, we deal with that one specifically. Drop __switchdev_port_attr_set() and update switchdev_port_attr_set() likewise. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28 03:44:31 +08:00
struct switchdev_notifier_port_attr_info info = {
.attr = &attr,
};
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
int err;
net: bridge: offload all port flags at once in br_setport If for example this command: ip link set swp0 type bridge_slave flood off mcast_flood off learning off succeeded at configuring BR_FLOOD and BR_MCAST_FLOOD but not at BR_LEARNING, there would be no attempt to revert the partial state in any way. Arguably, if the user changes more than one flag through the same netlink command, this one _should_ be all or nothing, which means it should be passed through switchdev as all or nothing. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 23:15:52 +08:00
mask &= BR_PORT_FLAGS_HW_OFFLOAD;
if (!mask)
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
return 0;
net: switchdev: pass flags and mask to both {PRE_,}BRIDGE_FLAGS attributes This switchdev attribute offers a counterproductive API for a driver writer, because although br_switchdev_set_port_flag gets passed a "flags" and a "mask", those are passed piecemeal to the driver, so while the PRE_BRIDGE_FLAGS listener knows what changed because it has the "mask", the BRIDGE_FLAGS listener doesn't, because it only has the final value. But certain drivers can offload only certain combinations of settings, like for example they cannot change unicast flooding independently of multicast flooding - they must be both on or both off. The way the information is passed to switchdev makes drivers not expressive enough, and unable to reject this request ahead of time, in the PRE_BRIDGE_FLAGS notifier, so they are forced to reject it during the deferred BRIDGE_FLAGS attribute, where the rejection is currently ignored. This patch also changes drivers to make use of the "mask" field for edge detection when possible. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 23:15:55 +08:00
attr.id = SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS;
attr.u.brport_flags.val = flags;
attr.u.brport_flags.mask = mask;
net: bridge: offload all port flags at once in br_setport If for example this command: ip link set swp0 type bridge_slave flood off mcast_flood off learning off succeeded at configuring BR_FLOOD and BR_MCAST_FLOOD but not at BR_LEARNING, there would be no attempt to revert the partial state in any way. Arguably, if the user changes more than one flag through the same netlink command, this one _should_ be all or nothing, which means it should be passed through switchdev as all or nothing. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 23:15:52 +08:00
net: switchdev: Replace port attr set SDO with a notification Drop switchdev_ops.switchdev_port_attr_set. Drop the uses of this field from all clients, which were migrated to use switchdev notification in the previous patches. Add a new function switchdev_port_attr_notify() that sends the switchdev notifications SWITCHDEV_PORT_ATTR_SET and calls the blocking (process) notifier chain. We have one odd case within net/bridge/br_switchdev.c with the SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS attribute identifier that requires executing from atomic context, we deal with that one specifically. Drop __switchdev_port_attr_set() and update switchdev_port_attr_set() likewise. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28 03:44:31 +08:00
/* We run from atomic context here */
err = call_switchdev_notifiers(SWITCHDEV_PORT_ATTR_SET, p->dev,
net: bridge: don't print in br_switchdev_set_port_flag For the netlink interface, propagate errors through extack rather than simply printing them to the console. For the sysfs interface, we still print to the console, but at least that's one layer higher than in switchdev, which also allows us to silently ignore the offloading of flags if that is ever needed in the future. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 23:15:53 +08:00
&info.info, extack);
net: switchdev: Replace port attr set SDO with a notification Drop switchdev_ops.switchdev_port_attr_set. Drop the uses of this field from all clients, which were migrated to use switchdev notification in the previous patches. Add a new function switchdev_port_attr_notify() that sends the switchdev notifications SWITCHDEV_PORT_ATTR_SET and calls the blocking (process) notifier chain. We have one odd case within net/bridge/br_switchdev.c with the SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS attribute identifier that requires executing from atomic context, we deal with that one specifically. Drop __switchdev_port_attr_set() and update switchdev_port_attr_set() likewise. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28 03:44:31 +08:00
err = notifier_to_errno(err);
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
if (err == -EOPNOTSUPP)
return 0;
net: bridge: Stop calling switchdev_port_attr_get() Now that all switchdev drivers have been converted to check the SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS flags and report flags that they do not support accordingly, we can migrate the bridge code to try to set that attribute first, check the results and then do the actual setting. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-21 08:58:24 +08:00
if (err) {
net: bridge: don't print in br_switchdev_set_port_flag For the netlink interface, propagate errors through extack rather than simply printing them to the console. For the sysfs interface, we still print to the console, but at least that's one layer higher than in switchdev, which also allows us to silently ignore the offloading of flags if that is ever needed in the future. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 23:15:53 +08:00
if (extack && !extack->_msg)
NL_SET_ERR_MSG_MOD(extack,
"bridge flag offload is not supported");
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
return -EOPNOTSUPP;
}
attr.id = SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS;
attr.flags = SWITCHDEV_F_DEFER;
net: bridge: Stop calling switchdev_port_attr_get() Now that all switchdev drivers have been converted to check the SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS flags and report flags that they do not support accordingly, we can migrate the bridge code to try to set that attribute first, check the results and then do the actual setting. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-21 08:58:24 +08:00
net: bridge: propagate extack through switchdev_port_attr_set The benefit is the ability to propagate errors from switchdev drivers for the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING and SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL attributes. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-14 04:43:17 +08:00
err = switchdev_port_attr_set(p->dev, &attr, extack);
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
if (err) {
net: bridge: propagate extack through switchdev_port_attr_set The benefit is the ability to propagate errors from switchdev drivers for the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING and SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL attributes. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-14 04:43:17 +08:00
if (extack && !extack->_msg)
NL_SET_ERR_MSG_MOD(extack,
"error setting offload flag on port");
net: bridge: Add support for offloading port attributes Currently the flood, learning and learning_sync port attributes are offloaded by setting the SELF flag. Add support for offloading the flood and learning attribute through the bridge code. In case of setting an unsupported flag on a offloded port the operation will fail. The learning_sync attribute doesn't have any software representation and cannot be offloaded through the bridge code. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:11 +08:00
return err;
}
return 0;
}
net: bridge: Add support for notifying devices about FDB add/del Currently the bridge doesn't notify the underlying devices about new FDBs learned. The FDB sync is placed on the switchdev notifier chain because devices may potentially learn FDB that are not directly related to their ports, for example: 1. Mixed SW/HW bridge - FDBs that point to the ASICs external devices should be offloaded as CPU traps in order to perform forwarding in slow path. 2. EVPN - Externally learned FDBs for the vtep device. Notification is sent only about static FDB add/del. This is done due to fact that currently this is the only scenario supported by switch drivers. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:14 +08:00
void
net: bridge: switchdev: send FDB notifications for host addresses Treat addresses added to the bridge itself in the same way as regular ports and send out a notification so that drivers may sync it down to the hardware FDB. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29 22:06:45 +08:00
br_switchdev_fdb_notify(struct net_bridge *br,
const struct net_bridge_fdb_entry *fdb, int type)
net: bridge: Add support for notifying devices about FDB add/del Currently the bridge doesn't notify the underlying devices about new FDBs learned. The FDB sync is placed on the switchdev notifier chain because devices may potentially learn FDB that are not directly related to their ports, for example: 1. Mixed SW/HW bridge - FDBs that point to the ASICs external devices should be offloaded as CPU traps in order to perform forwarding in slow path. 2. EVPN - Externally learned FDBs for the vtep device. Notification is sent only about static FDB add/del. This is done due to fact that currently this is the only scenario supported by switch drivers. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:14 +08:00
{
net: bridge: use READ_ONCE() and WRITE_ONCE() compiler barriers for fdb->dst Annotate the writer side of fdb->dst: - fdb_create() - br_fdb_update() - fdb_add_entry() - br_fdb_external_learn_add() with WRITE_ONCE() and the reader side: - br_fdb_test_addr() - br_fdb_update() - fdb_fill_info() - fdb_add_entry() - fdb_delete_by_addr_and_port() - br_fdb_external_learn_add() - br_switchdev_fdb_notify() with compiler barriers such that the readers do not attempt to reload fdb->dst multiple times, leading to potentially different destination ports when the fdb entry is updated concurrently. This is especially important in read-side sections where fdb->dst is used more than once, but let's convert all accesses for the sake of uniformity. Suggested-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29 22:06:44 +08:00
const struct net_bridge_port *dst = READ_ONCE(fdb->dst);
net: bridge: switchdev: send FDB notifications for host addresses Treat addresses added to the bridge itself in the same way as regular ports and send out a notification so that drivers may sync it down to the hardware FDB. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29 22:06:45 +08:00
struct net_device *dev = dst ? dst->dev : br->dev;
net: bridge: switchdev: refactor br_switchdev_fdb_notify Instead of having to add more and more arguments to br_switchdev_fdb_call_notifiers, get rid of it and build the info struct directly in br_switchdev_fdb_notify. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-15 00:52:55 +08:00
struct switchdev_notifier_fdb_info info = {
.addr = fdb->key.addr.addr,
.vid = fdb->key.vlan_id,
.added_by_user = test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags),
net: bridge: switchdev: include local flag in FDB notifications As explained in bugfix commit 6ab4c3117aec ("net: bridge: don't notify switchdev for local FDB addresses") as well as in this discussion: https://lore.kernel.org/netdev/20210117193009.io3nungdwuzmo5f7@skbuf/ the switchdev notifiers for FDB entries managed to have a zero-day bug, which was that drivers would not know what to do with local FDB entries, because they were not told that they are local. The bug fix was to simply not notify them of those addresses. Let us now add the 'is_local' bit to bridge FDB entries, and make all drivers ignore these entries by their own choice. Co-developed-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-15 00:52:56 +08:00
.is_local = test_bit(BR_FDB_LOCAL, &fdb->flags),
net: bridge: switchdev: refactor br_switchdev_fdb_notify Instead of having to add more and more arguments to br_switchdev_fdb_call_notifiers, get rid of it and build the info struct directly in br_switchdev_fdb_notify. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-15 00:52:55 +08:00
.offloaded = test_bit(BR_FDB_OFFLOADED, &fdb->flags),
};
net: bridge: Add support for notifying devices about FDB add/del Currently the bridge doesn't notify the underlying devices about new FDBs learned. The FDB sync is placed on the switchdev notifier chain because devices may potentially learn FDB that are not directly related to their ports, for example: 1. Mixed SW/HW bridge - FDBs that point to the ASICs external devices should be offloaded as CPU traps in order to perform forwarding in slow path. 2. EVPN - Externally learned FDBs for the vtep device. Notification is sent only about static FDB add/del. This is done due to fact that currently this is the only scenario supported by switch drivers. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:14 +08:00
switch (type) {
case RTM_DELNEIGH:
net: bridge: switchdev: refactor br_switchdev_fdb_notify Instead of having to add more and more arguments to br_switchdev_fdb_call_notifiers, get rid of it and build the info struct directly in br_switchdev_fdb_notify. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-15 00:52:55 +08:00
call_switchdev_notifiers(SWITCHDEV_FDB_DEL_TO_DEVICE,
net: bridge: switchdev: send FDB notifications for host addresses Treat addresses added to the bridge itself in the same way as regular ports and send out a notification so that drivers may sync it down to the hardware FDB. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29 22:06:45 +08:00
dev, &info.info, NULL);
net: bridge: Add support for notifying devices about FDB add/del Currently the bridge doesn't notify the underlying devices about new FDBs learned. The FDB sync is placed on the switchdev notifier chain because devices may potentially learn FDB that are not directly related to their ports, for example: 1. Mixed SW/HW bridge - FDBs that point to the ASICs external devices should be offloaded as CPU traps in order to perform forwarding in slow path. 2. EVPN - Externally learned FDBs for the vtep device. Notification is sent only about static FDB add/del. This is done due to fact that currently this is the only scenario supported by switch drivers. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:14 +08:00
break;
case RTM_NEWNEIGH:
net: bridge: switchdev: refactor br_switchdev_fdb_notify Instead of having to add more and more arguments to br_switchdev_fdb_call_notifiers, get rid of it and build the info struct directly in br_switchdev_fdb_notify. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-15 00:52:55 +08:00
call_switchdev_notifiers(SWITCHDEV_FDB_ADD_TO_DEVICE,
net: bridge: switchdev: send FDB notifications for host addresses Treat addresses added to the bridge itself in the same way as regular ports and send out a notification so that drivers may sync it down to the hardware FDB. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29 22:06:45 +08:00
dev, &info.info, NULL);
net: bridge: Add support for notifying devices about FDB add/del Currently the bridge doesn't notify the underlying devices about new FDBs learned. The FDB sync is placed on the switchdev notifier chain because devices may potentially learn FDB that are not directly related to their ports, for example: 1. Mixed SW/HW bridge - FDBs that point to the ASICs external devices should be offloaded as CPU traps in order to perform forwarding in slow path. 2. EVPN - Externally learned FDBs for the vtep device. Notification is sent only about static FDB add/del. This is done due to fact that currently this is the only scenario supported by switch drivers. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:44:14 +08:00
break;
}
}
net: bridge: Extract boilerplate around switchdev_port_obj_*() A call to switchdev_port_obj_add() or switchdev_port_obj_del() involves initializing a struct switchdev_obj_port_vlan, a piece of code that repeats on each call site almost verbatim. While in the current codebase there is just one duplicated add call, the follow-up patches add more of both add and del calls. Thus to remove the duplication, extract the repetition into named functions and reuse. Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-30 08:56:03 +08:00
net: bridge: Propagate extack to switchdev ndo_bridge_setlink has been updated in the previous patch to have extack available, and changelink RTNL op has had this argument since the time extack was added. Propagate both through the bridge driver to eventually reach br_switchdev_port_vlan_add(), where it will be used by subsequent patches. Signed-off-by: Petr Machata <petrm@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Ivan Vecera <ivecera@redhat.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-13 01:02:50 +08:00
int br_switchdev_port_vlan_add(struct net_device *dev, u16 vid, u16 flags,
struct netlink_ext_ack *extack)
net: bridge: Extract boilerplate around switchdev_port_obj_*() A call to switchdev_port_obj_add() or switchdev_port_obj_del() involves initializing a struct switchdev_obj_port_vlan, a piece of code that repeats on each call site almost verbatim. While in the current codebase there is just one duplicated add call, the follow-up patches add more of both add and del calls. Thus to remove the duplication, extract the repetition into named functions and reuse. Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-30 08:56:03 +08:00
{
struct switchdev_obj_port_vlan v = {
.obj.orig_dev = dev,
.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
.flags = flags,
net: switchdev: remove vid_begin -> vid_end range from VLAN objects The call path of a switchdev VLAN addition to the bridge looks something like this today: nbp_vlan_init | __br_vlan_set_default_pvid | | | | | br_afspec | | | | | | | v | | | br_process_vlan_info | | | | | | | v | | | br_vlan_info | | | / \ / | | / \ / | | / \ / | | / \ / v v v v v nbp_vlan_add br_vlan_add ------+ | ^ ^ | | | / | | | | / / / | \ br_vlan_get_master/ / v \ ^ / / br_vlan_add_existing \ | / / | \ | / / / \ | / / / \ | / / / \ | / / / v | | v / __vlan_add / / | / / | / v | / __vlan_vid_add | / \ | / v v v br_switchdev_port_vlan_add The ranges UAPI was introduced to the bridge in commit bdced7ef7838 ("bridge: support for multiple vlans and vlan ranges in setlink and dellink requests") (Jan 10 2015). But the VLAN ranges (parsed in br_afspec) have always been passed one by one, through struct bridge_vlan_info tmp_vinfo, to br_vlan_info. So the range never went too far in depth. Then Scott Feldman introduced the switchdev_port_bridge_setlink function in commit 47f8328bb1a4 ("switchdev: add new switchdev bridge setlink"). That marked the introduction of the SWITCHDEV_OBJ_PORT_VLAN, which made full use of the range. But switchdev_port_bridge_setlink was called like this: br_setlink -> br_afspec -> switchdev_port_bridge_setlink Basically, the switchdev and the bridge code were not tightly integrated. Then commit 41c498b9359e ("bridge: restore br_setlink back to original") came, and switchdev drivers were required to implement .ndo_bridge_setlink = switchdev_port_bridge_setlink for a while. In the meantime, commits such as 0944d6b5a2fa ("bridge: try switchdev op first in __vlan_vid_add/del") finally made switchdev penetrate the br_vlan_info() barrier and start to develop the call path we have today. But remember, br_vlan_info() still receives VLANs one by one. Then Arkadi Sharshevsky refactored the switchdev API in 2017 in commit 29ab586c3d83 ("net: switchdev: Remove bridge bypass support from switchdev") so that drivers would not implement .ndo_bridge_setlink any longer. The switchdev_port_bridge_setlink also got deleted. This refactoring removed the parallel bridge_setlink implementation from switchdev, and left the only switchdev VLAN objects to be the ones offloaded from __vlan_vid_add (basically RX filtering) and __vlan_add (the latter coming from commit 9c86ce2c1ae3 ("net: bridge: Notify about bridge VLANs")). That is to say, today the switchdev VLAN object ranges are not used in the kernel. Refactoring the above call path is a bit complicated, when the bridge VLAN call path is already a bit complicated. Let's go off and finish the job of commit 29ab586c3d83 by deleting the bogus iteration through the VLAN ranges from the drivers. Some aspects of this feature never made too much sense in the first place. For example, what is a range of VLANs all having the BRIDGE_VLAN_INFO_PVID flag supposed to mean, when a port can obviously have a single pvid? This particular configuration _is_ denied as of commit 6623c60dc28e ("bridge: vlan: enforce no pvid flag in vlan ranges"), but from an API perspective, the driver still has to play pretend, and only offload the vlan->vid_end as pvid. And the addition of a switchdev VLAN object can modify the flags of another, completely unrelated, switchdev VLAN object! (a VLAN that is PVID will invalidate the PVID flag from whatever other VLAN had previously been offloaded with switchdev and had that flag. Yet switchdev never notifies about that change, drivers are supposed to guess). Nonetheless, having a VLAN range in the API makes error handling look scarier than it really is - unwinding on errors and all of that. When in reality, no one really calls this API with more than one VLAN. It is all unnecessary complexity. And despite appearing pretentious (two-phase transactional model and all), the switchdev API is really sloppy because the VLAN addition and removal operations are not paired with one another (you can add a VLAN 100 times and delete it just once). The bridge notifies through switchdev of a VLAN addition not only when the flags of an existing VLAN change, but also when nothing changes. There are switchdev drivers out there who don't like adding a VLAN that has already been added, and those checks don't really belong at driver level. But the fact that the API contains ranges is yet another factor that prevents this from being addressed in the future. Of the existing switchdev pieces of hardware, it appears that only Mellanox Spectrum supports offloading more than one VLAN at a time, through mlxsw_sp_port_vlan_set. I have kept that code internal to the driver, because there is some more bookkeeping that makes use of it, but I deleted it from the switchdev API. But since the switchdev support for ranges has already been de facto deleted by a Mellanox employee and nobody noticed for 4 years, I'm going to assume it's not a biggie. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> # switchdev and mlxsw Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-09 08:01:46 +08:00
.vid = vid,
net: bridge: Extract boilerplate around switchdev_port_obj_*() A call to switchdev_port_obj_add() or switchdev_port_obj_del() involves initializing a struct switchdev_obj_port_vlan, a piece of code that repeats on each call site almost verbatim. While in the current codebase there is just one duplicated add call, the follow-up patches add more of both add and del calls. Thus to remove the duplication, extract the repetition into named functions and reuse. Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-30 08:56:03 +08:00
};
net: switchdev: Add extack argument to switchdev_port_obj_add() After the previous patch, bridge driver has extack argument available to pass to switchdev. Therefore extend switchdev_port_obj_add() with this argument, updating all callers, and passing the argument through to switchdev_port_obj_notify(). Signed-off-by: Petr Machata <petrm@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Ivan Vecera <ivecera@redhat.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-13 01:02:52 +08:00
return switchdev_port_obj_add(dev, &v.obj, extack);
net: bridge: Extract boilerplate around switchdev_port_obj_*() A call to switchdev_port_obj_add() or switchdev_port_obj_del() involves initializing a struct switchdev_obj_port_vlan, a piece of code that repeats on each call site almost verbatim. While in the current codebase there is just one duplicated add call, the follow-up patches add more of both add and del calls. Thus to remove the duplication, extract the repetition into named functions and reuse. Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-30 08:56:03 +08:00
}
int br_switchdev_port_vlan_del(struct net_device *dev, u16 vid)
{
struct switchdev_obj_port_vlan v = {
.obj.orig_dev = dev,
.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
net: switchdev: remove vid_begin -> vid_end range from VLAN objects The call path of a switchdev VLAN addition to the bridge looks something like this today: nbp_vlan_init | __br_vlan_set_default_pvid | | | | | br_afspec | | | | | | | v | | | br_process_vlan_info | | | | | | | v | | | br_vlan_info | | | / \ / | | / \ / | | / \ / | | / \ / v v v v v nbp_vlan_add br_vlan_add ------+ | ^ ^ | | | / | | | | / / / | \ br_vlan_get_master/ / v \ ^ / / br_vlan_add_existing \ | / / | \ | / / / \ | / / / \ | / / / \ | / / / v | | v / __vlan_add / / | / / | / v | / __vlan_vid_add | / \ | / v v v br_switchdev_port_vlan_add The ranges UAPI was introduced to the bridge in commit bdced7ef7838 ("bridge: support for multiple vlans and vlan ranges in setlink and dellink requests") (Jan 10 2015). But the VLAN ranges (parsed in br_afspec) have always been passed one by one, through struct bridge_vlan_info tmp_vinfo, to br_vlan_info. So the range never went too far in depth. Then Scott Feldman introduced the switchdev_port_bridge_setlink function in commit 47f8328bb1a4 ("switchdev: add new switchdev bridge setlink"). That marked the introduction of the SWITCHDEV_OBJ_PORT_VLAN, which made full use of the range. But switchdev_port_bridge_setlink was called like this: br_setlink -> br_afspec -> switchdev_port_bridge_setlink Basically, the switchdev and the bridge code were not tightly integrated. Then commit 41c498b9359e ("bridge: restore br_setlink back to original") came, and switchdev drivers were required to implement .ndo_bridge_setlink = switchdev_port_bridge_setlink for a while. In the meantime, commits such as 0944d6b5a2fa ("bridge: try switchdev op first in __vlan_vid_add/del") finally made switchdev penetrate the br_vlan_info() barrier and start to develop the call path we have today. But remember, br_vlan_info() still receives VLANs one by one. Then Arkadi Sharshevsky refactored the switchdev API in 2017 in commit 29ab586c3d83 ("net: switchdev: Remove bridge bypass support from switchdev") so that drivers would not implement .ndo_bridge_setlink any longer. The switchdev_port_bridge_setlink also got deleted. This refactoring removed the parallel bridge_setlink implementation from switchdev, and left the only switchdev VLAN objects to be the ones offloaded from __vlan_vid_add (basically RX filtering) and __vlan_add (the latter coming from commit 9c86ce2c1ae3 ("net: bridge: Notify about bridge VLANs")). That is to say, today the switchdev VLAN object ranges are not used in the kernel. Refactoring the above call path is a bit complicated, when the bridge VLAN call path is already a bit complicated. Let's go off and finish the job of commit 29ab586c3d83 by deleting the bogus iteration through the VLAN ranges from the drivers. Some aspects of this feature never made too much sense in the first place. For example, what is a range of VLANs all having the BRIDGE_VLAN_INFO_PVID flag supposed to mean, when a port can obviously have a single pvid? This particular configuration _is_ denied as of commit 6623c60dc28e ("bridge: vlan: enforce no pvid flag in vlan ranges"), but from an API perspective, the driver still has to play pretend, and only offload the vlan->vid_end as pvid. And the addition of a switchdev VLAN object can modify the flags of another, completely unrelated, switchdev VLAN object! (a VLAN that is PVID will invalidate the PVID flag from whatever other VLAN had previously been offloaded with switchdev and had that flag. Yet switchdev never notifies about that change, drivers are supposed to guess). Nonetheless, having a VLAN range in the API makes error handling look scarier than it really is - unwinding on errors and all of that. When in reality, no one really calls this API with more than one VLAN. It is all unnecessary complexity. And despite appearing pretentious (two-phase transactional model and all), the switchdev API is really sloppy because the VLAN addition and removal operations are not paired with one another (you can add a VLAN 100 times and delete it just once). The bridge notifies through switchdev of a VLAN addition not only when the flags of an existing VLAN change, but also when nothing changes. There are switchdev drivers out there who don't like adding a VLAN that has already been added, and those checks don't really belong at driver level. But the fact that the API contains ranges is yet another factor that prevents this from being addressed in the future. Of the existing switchdev pieces of hardware, it appears that only Mellanox Spectrum supports offloading more than one VLAN at a time, through mlxsw_sp_port_vlan_set. I have kept that code internal to the driver, because there is some more bookkeeping that makes use of it, but I deleted it from the switchdev API. But since the switchdev support for ranges has already been de facto deleted by a Mellanox employee and nobody noticed for 4 years, I'm going to assume it's not a biggie. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> # switchdev and mlxsw Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-09 08:01:46 +08:00
.vid = vid,
net: bridge: Extract boilerplate around switchdev_port_obj_*() A call to switchdev_port_obj_add() or switchdev_port_obj_del() involves initializing a struct switchdev_obj_port_vlan, a piece of code that repeats on each call site almost verbatim. While in the current codebase there is just one duplicated add call, the follow-up patches add more of both add and del calls. Thus to remove the duplication, extract the repetition into named functions and reuse. Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-30 08:56:03 +08:00
};
return switchdev_port_obj_del(dev, &v.obj);
}
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
static int nbp_switchdev_hwdom_set(struct net_bridge_port *joining)
{
struct net_bridge *br = joining->br;
struct net_bridge_port *p;
int hwdom;
/* joining is yet to be added to the port list. */
list_for_each_entry(p, &br->port_list, list) {
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
if (netdev_phys_item_id_same(&joining->ppid, &p->ppid)) {
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
joining->hwdom = p->hwdom;
return 0;
}
}
hwdom = find_next_zero_bit(&br->busy_hwdoms, BR_HWDOM_MAX, 1);
if (hwdom >= BR_HWDOM_MAX)
return -EBUSY;
set_bit(hwdom, &br->busy_hwdoms);
joining->hwdom = hwdom;
return 0;
}
static void nbp_switchdev_hwdom_put(struct net_bridge_port *leaving)
{
struct net_bridge *br = leaving->br;
struct net_bridge_port *p;
/* leaving is no longer in the port list. */
list_for_each_entry(p, &br->port_list, list) {
if (p->hwdom == leaving->hwdom)
return;
}
clear_bit(leaving->hwdom, &br->busy_hwdoms);
}
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
static int nbp_switchdev_add(struct net_bridge_port *p,
struct netdev_phys_item_id ppid,
struct netlink_ext_ack *extack)
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
{
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
if (p->offload_count) {
/* Prevent unsupported configurations such as a bridge port
* which is a bonding interface, and the member ports are from
* different hardware switches.
*/
if (!netdev_phys_item_id_same(&p->ppid, &ppid)) {
NL_SET_ERR_MSG_MOD(extack,
"Same bridge port cannot be offloaded by two physical switches");
return -EBUSY;
}
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
/* Tolerate drivers that call switchdev_bridge_port_offload()
* more than once for the same bridge port, such as when the
* bridge port is an offloaded bonding/team interface.
*/
p->offload_count++;
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
return 0;
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
}
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
p->ppid = ppid;
p->offload_count = 1;
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
return nbp_switchdev_hwdom_set(p);
}
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
static void nbp_switchdev_del(struct net_bridge_port *p)
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
{
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
if (WARN_ON(!p->offload_count))
return;
p->offload_count--;
if (p->offload_count)
return;
net: bridge: switchdev: recycle unused hwdoms Since hwdoms have only been used thus far for equality comparisons, the bridge has used the simplest possible assignment policy; using a counter to keep track of the last value handed out. With the upcoming transmit offloading, we need to perform set operations efficiently based on hwdoms, e.g. we want to answer questions like "has this skb been forwarded to any port within this hwdom?" Move to a bitmap-based allocation scheme that recycles hwdoms once all members leaves the bridge. This means that we can use a single unsigned long to keep track of the hwdoms that have received an skb. v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX) into a plain unsigned long. v2->v6: none Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:00 +08:00
if (p->hwdom)
nbp_switchdev_hwdom_put(p);
}
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
net: bridge: move the switchdev object replay helpers to "push" mode Starting with commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"), DSA has introduced some bridge helpers that replay switchdev events (FDB/MDB/VLAN additions and deletions) that can be lost by the switchdev drivers in a variety of circumstances: - an IP multicast group was host-joined on the bridge itself before any switchdev port joined the bridge, leading to the host MDB entries missing in the hardware database. - during the bridge creation process, the MAC address of the bridge was added to the FDB as an entry pointing towards the bridge device itself, but with no switchdev ports being part of the bridge yet, this local FDB entry would remain unknown to the switchdev hardware database. - a VLAN/FDB/MDB was added to a bridge port that is a LAG interface, before any switchdev port joined that LAG, leading to the hardware database missing those entries. - a switchdev port left a LAG that is a bridge port, while the LAG remained part of the bridge, and all FDB/MDB/VLAN entries remained installed in the hardware database of the switchdev port. Also, since commit 0d2cfbd41c4a ("net: bridge: ignore switchdev events for LAG ports which didn't request replay"), DSA introduced a method, based on a const void *ctx, to ensure that two switchdev ports under the same LAG that is a bridge port do not see the same MDB/VLAN entry being replayed twice by the bridge, once for every bridge port that joins the LAG. With so many ordering corner cases being possible, it seems unreasonable to expect a switchdev driver writer to get it right from the first try. Therefore, now that DSA has experimented with the bridge replay helpers for a little bit, we can move the code to the bridge driver where it is more readily available to all switchdev drivers. To convert the switchdev object replay helpers from "pull mode" (where the driver asks for them) to a "push mode" (where the bridge offers them automatically), the biggest problem is that the bridge needs to be aware when a switchdev port joins and leaves, even when the switchdev is only indirectly a bridge port (for example when the bridge port is a LAG upper of the switchdev). Luckily, we already have a hook for that, in the form of the newly introduced switchdev_bridge_port_offload() and switchdev_bridge_port_unoffload() calls. These offer a natural place for hooking the object addition and deletion replays. Extend the above 2 functions with: - pointers to the switchdev atomic notifier (for FDB replays) and the blocking notifier (for MDB and VLAN replays). - the "const void *ctx" argument required for drivers to be able to disambiguate between which port is targeted, when multiple ports are lowers of the same LAG that is a bridge port. Most of the drivers pass NULL to this argument, except the ones that support LAG offload and have the proper context check already in place in the switchdev blocking notifier handler. Also unexport the replay helpers, since nobody except the bridge calls them directly now. Note that: (a) we abuse the terminology slightly, because FDB entries are not "switchdev objects", but we count them as objects nonetheless. With no direct way to prove it, I think they are not modeled as switchdev objects because those can only be installed by the bridge to the hardware (as opposed to FDB entries which can be propagated in the other direction too). This is merely an abuse of terms, FDB entries are replayed too, despite not being objects. (b) the bridge does not attempt to sync port attributes to newly joined ports, just the countable stuff (the objects). The reason for this is simple: no universal and symmetric way to sync and unsync them is known. For example, VLAN filtering: what to do on unsync, disable or leave it enabled? Similarly, STP state, ageing timer, etc etc. What a switchdev port does when it becomes standalone again is not really up to the bridge's competence, and the driver should deal with it. On the other hand, replaying deletions of switchdev objects can be seen a matter of cleanup and therefore be treated by the bridge, hence this patch. We make the replay helpers opt-in for drivers, because they might not bring immediate benefits for them: - nbp_vlan_init() is called _after_ netdev_master_upper_dev_link(), so br_vlan_replay() should not do anything for the new drivers on which we call it. The existing drivers where there was even a slight possibility for there to exist a VLAN on a bridge port before they join it are already guarded against this: mlxsw and prestera deny joining LAG interfaces that are members of a bridge. - br_fdb_replay() should now notify of local FDB entries, but I patched all drivers except DSA to ignore these new entries in commit 2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB notifications"). Driver authors can lift this restriction as they wish, and when they do, they can also opt into the FDB replay functionality. - br_mdb_replay() should fix a real issue which is described in commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"). However most drivers do not offload the SWITCHDEV_OBJ_ID_HOST_MDB to see this issue: only cpsw and am65_cpsw offload this switchdev object, and I don't completely understand the way in which they offload this switchdev object anyway. So I'll leave it up to these drivers' respective maintainers to opt into br_mdb_replay(). So most of the drivers pass NULL notifier blocks for the replay helpers, except: - dpaa2-switch which was already acked/regression-tested with the helpers enabled (and there isn't much of a downside in having them) - ocelot which already had replay logic in "pull" mode - DSA which already had replay logic in "pull" mode An important observation is that the drivers which don't currently request bridge event replays don't even have the switchdev_bridge_port_{offload,unoffload} calls placed in proper places right now. This was done to avoid unnecessary rework for drivers which might never even add support for this. For driver writers who wish to add replay support, this can be used as a tentative placement guide: https://patchwork.kernel.org/project/netdevbpf/patch/20210720134655.892334-11-vladimir.oltean@nxp.com/ Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:03 +08:00
static int nbp_switchdev_sync_objs(struct net_bridge_port *p, const void *ctx,
struct notifier_block *atomic_nb,
struct notifier_block *blocking_nb,
struct netlink_ext_ack *extack)
{
struct net_device *br_dev = p->br->dev;
struct net_device *dev = p->dev;
int err;
err = br_vlan_replay(br_dev, dev, ctx, true, blocking_nb, extack);
if (err && err != -EOPNOTSUPP)
return err;
err = br_mdb_replay(br_dev, dev, ctx, true, blocking_nb, extack);
if (err && err != -EOPNOTSUPP)
return err;
/* Forwarding and termination FDB entries on the port */
err = br_fdb_replay(br_dev, dev, ctx, true, atomic_nb);
if (err && err != -EOPNOTSUPP)
return err;
/* Termination FDB entries on the bridge itself */
err = br_fdb_replay(br_dev, br_dev, ctx, true, atomic_nb);
if (err && err != -EOPNOTSUPP)
return err;
return 0;
}
static void nbp_switchdev_unsync_objs(struct net_bridge_port *p,
const void *ctx,
struct notifier_block *atomic_nb,
struct notifier_block *blocking_nb)
{
struct net_device *br_dev = p->br->dev;
struct net_device *dev = p->dev;
br_vlan_replay(br_dev, dev, ctx, false, blocking_nb, NULL);
br_mdb_replay(br_dev, dev, ctx, false, blocking_nb, NULL);
/* Forwarding and termination FDB entries on the port */
br_fdb_replay(br_dev, dev, ctx, false, atomic_nb);
/* Termination FDB entries on the bridge itself */
br_fdb_replay(br_dev, br_dev, ctx, false, atomic_nb);
}
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
/* Let the bridge know that this port is offloaded, so that it can assign a
* switchdev hardware domain to it.
*/
int switchdev_bridge_port_offload(struct net_device *brport_dev,
net: bridge: move the switchdev object replay helpers to "push" mode Starting with commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"), DSA has introduced some bridge helpers that replay switchdev events (FDB/MDB/VLAN additions and deletions) that can be lost by the switchdev drivers in a variety of circumstances: - an IP multicast group was host-joined on the bridge itself before any switchdev port joined the bridge, leading to the host MDB entries missing in the hardware database. - during the bridge creation process, the MAC address of the bridge was added to the FDB as an entry pointing towards the bridge device itself, but with no switchdev ports being part of the bridge yet, this local FDB entry would remain unknown to the switchdev hardware database. - a VLAN/FDB/MDB was added to a bridge port that is a LAG interface, before any switchdev port joined that LAG, leading to the hardware database missing those entries. - a switchdev port left a LAG that is a bridge port, while the LAG remained part of the bridge, and all FDB/MDB/VLAN entries remained installed in the hardware database of the switchdev port. Also, since commit 0d2cfbd41c4a ("net: bridge: ignore switchdev events for LAG ports which didn't request replay"), DSA introduced a method, based on a const void *ctx, to ensure that two switchdev ports under the same LAG that is a bridge port do not see the same MDB/VLAN entry being replayed twice by the bridge, once for every bridge port that joins the LAG. With so many ordering corner cases being possible, it seems unreasonable to expect a switchdev driver writer to get it right from the first try. Therefore, now that DSA has experimented with the bridge replay helpers for a little bit, we can move the code to the bridge driver where it is more readily available to all switchdev drivers. To convert the switchdev object replay helpers from "pull mode" (where the driver asks for them) to a "push mode" (where the bridge offers them automatically), the biggest problem is that the bridge needs to be aware when a switchdev port joins and leaves, even when the switchdev is only indirectly a bridge port (for example when the bridge port is a LAG upper of the switchdev). Luckily, we already have a hook for that, in the form of the newly introduced switchdev_bridge_port_offload() and switchdev_bridge_port_unoffload() calls. These offer a natural place for hooking the object addition and deletion replays. Extend the above 2 functions with: - pointers to the switchdev atomic notifier (for FDB replays) and the blocking notifier (for MDB and VLAN replays). - the "const void *ctx" argument required for drivers to be able to disambiguate between which port is targeted, when multiple ports are lowers of the same LAG that is a bridge port. Most of the drivers pass NULL to this argument, except the ones that support LAG offload and have the proper context check already in place in the switchdev blocking notifier handler. Also unexport the replay helpers, since nobody except the bridge calls them directly now. Note that: (a) we abuse the terminology slightly, because FDB entries are not "switchdev objects", but we count them as objects nonetheless. With no direct way to prove it, I think they are not modeled as switchdev objects because those can only be installed by the bridge to the hardware (as opposed to FDB entries which can be propagated in the other direction too). This is merely an abuse of terms, FDB entries are replayed too, despite not being objects. (b) the bridge does not attempt to sync port attributes to newly joined ports, just the countable stuff (the objects). The reason for this is simple: no universal and symmetric way to sync and unsync them is known. For example, VLAN filtering: what to do on unsync, disable or leave it enabled? Similarly, STP state, ageing timer, etc etc. What a switchdev port does when it becomes standalone again is not really up to the bridge's competence, and the driver should deal with it. On the other hand, replaying deletions of switchdev objects can be seen a matter of cleanup and therefore be treated by the bridge, hence this patch. We make the replay helpers opt-in for drivers, because they might not bring immediate benefits for them: - nbp_vlan_init() is called _after_ netdev_master_upper_dev_link(), so br_vlan_replay() should not do anything for the new drivers on which we call it. The existing drivers where there was even a slight possibility for there to exist a VLAN on a bridge port before they join it are already guarded against this: mlxsw and prestera deny joining LAG interfaces that are members of a bridge. - br_fdb_replay() should now notify of local FDB entries, but I patched all drivers except DSA to ignore these new entries in commit 2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB notifications"). Driver authors can lift this restriction as they wish, and when they do, they can also opt into the FDB replay functionality. - br_mdb_replay() should fix a real issue which is described in commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"). However most drivers do not offload the SWITCHDEV_OBJ_ID_HOST_MDB to see this issue: only cpsw and am65_cpsw offload this switchdev object, and I don't completely understand the way in which they offload this switchdev object anyway. So I'll leave it up to these drivers' respective maintainers to opt into br_mdb_replay(). So most of the drivers pass NULL notifier blocks for the replay helpers, except: - dpaa2-switch which was already acked/regression-tested with the helpers enabled (and there isn't much of a downside in having them) - ocelot which already had replay logic in "pull" mode - DSA which already had replay logic in "pull" mode An important observation is that the drivers which don't currently request bridge event replays don't even have the switchdev_bridge_port_{offload,unoffload} calls placed in proper places right now. This was done to avoid unnecessary rework for drivers which might never even add support for this. For driver writers who wish to add replay support, this can be used as a tentative placement guide: https://patchwork.kernel.org/project/netdevbpf/patch/20210720134655.892334-11-vladimir.oltean@nxp.com/ Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:03 +08:00
struct net_device *dev, const void *ctx,
struct notifier_block *atomic_nb,
struct notifier_block *blocking_nb,
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
struct netlink_ext_ack *extack)
{
struct netdev_phys_item_id ppid;
struct net_bridge_port *p;
int err;
ASSERT_RTNL();
p = br_port_get_rtnl(brport_dev);
if (!p)
return -ENODEV;
err = dev_get_port_parent_id(dev, &ppid, false);
if (err)
return err;
net: bridge: move the switchdev object replay helpers to "push" mode Starting with commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"), DSA has introduced some bridge helpers that replay switchdev events (FDB/MDB/VLAN additions and deletions) that can be lost by the switchdev drivers in a variety of circumstances: - an IP multicast group was host-joined on the bridge itself before any switchdev port joined the bridge, leading to the host MDB entries missing in the hardware database. - during the bridge creation process, the MAC address of the bridge was added to the FDB as an entry pointing towards the bridge device itself, but with no switchdev ports being part of the bridge yet, this local FDB entry would remain unknown to the switchdev hardware database. - a VLAN/FDB/MDB was added to a bridge port that is a LAG interface, before any switchdev port joined that LAG, leading to the hardware database missing those entries. - a switchdev port left a LAG that is a bridge port, while the LAG remained part of the bridge, and all FDB/MDB/VLAN entries remained installed in the hardware database of the switchdev port. Also, since commit 0d2cfbd41c4a ("net: bridge: ignore switchdev events for LAG ports which didn't request replay"), DSA introduced a method, based on a const void *ctx, to ensure that two switchdev ports under the same LAG that is a bridge port do not see the same MDB/VLAN entry being replayed twice by the bridge, once for every bridge port that joins the LAG. With so many ordering corner cases being possible, it seems unreasonable to expect a switchdev driver writer to get it right from the first try. Therefore, now that DSA has experimented with the bridge replay helpers for a little bit, we can move the code to the bridge driver where it is more readily available to all switchdev drivers. To convert the switchdev object replay helpers from "pull mode" (where the driver asks for them) to a "push mode" (where the bridge offers them automatically), the biggest problem is that the bridge needs to be aware when a switchdev port joins and leaves, even when the switchdev is only indirectly a bridge port (for example when the bridge port is a LAG upper of the switchdev). Luckily, we already have a hook for that, in the form of the newly introduced switchdev_bridge_port_offload() and switchdev_bridge_port_unoffload() calls. These offer a natural place for hooking the object addition and deletion replays. Extend the above 2 functions with: - pointers to the switchdev atomic notifier (for FDB replays) and the blocking notifier (for MDB and VLAN replays). - the "const void *ctx" argument required for drivers to be able to disambiguate between which port is targeted, when multiple ports are lowers of the same LAG that is a bridge port. Most of the drivers pass NULL to this argument, except the ones that support LAG offload and have the proper context check already in place in the switchdev blocking notifier handler. Also unexport the replay helpers, since nobody except the bridge calls them directly now. Note that: (a) we abuse the terminology slightly, because FDB entries are not "switchdev objects", but we count them as objects nonetheless. With no direct way to prove it, I think they are not modeled as switchdev objects because those can only be installed by the bridge to the hardware (as opposed to FDB entries which can be propagated in the other direction too). This is merely an abuse of terms, FDB entries are replayed too, despite not being objects. (b) the bridge does not attempt to sync port attributes to newly joined ports, just the countable stuff (the objects). The reason for this is simple: no universal and symmetric way to sync and unsync them is known. For example, VLAN filtering: what to do on unsync, disable or leave it enabled? Similarly, STP state, ageing timer, etc etc. What a switchdev port does when it becomes standalone again is not really up to the bridge's competence, and the driver should deal with it. On the other hand, replaying deletions of switchdev objects can be seen a matter of cleanup and therefore be treated by the bridge, hence this patch. We make the replay helpers opt-in for drivers, because they might not bring immediate benefits for them: - nbp_vlan_init() is called _after_ netdev_master_upper_dev_link(), so br_vlan_replay() should not do anything for the new drivers on which we call it. The existing drivers where there was even a slight possibility for there to exist a VLAN on a bridge port before they join it are already guarded against this: mlxsw and prestera deny joining LAG interfaces that are members of a bridge. - br_fdb_replay() should now notify of local FDB entries, but I patched all drivers except DSA to ignore these new entries in commit 2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB notifications"). Driver authors can lift this restriction as they wish, and when they do, they can also opt into the FDB replay functionality. - br_mdb_replay() should fix a real issue which is described in commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"). However most drivers do not offload the SWITCHDEV_OBJ_ID_HOST_MDB to see this issue: only cpsw and am65_cpsw offload this switchdev object, and I don't completely understand the way in which they offload this switchdev object anyway. So I'll leave it up to these drivers' respective maintainers to opt into br_mdb_replay(). So most of the drivers pass NULL notifier blocks for the replay helpers, except: - dpaa2-switch which was already acked/regression-tested with the helpers enabled (and there isn't much of a downside in having them) - ocelot which already had replay logic in "pull" mode - DSA which already had replay logic in "pull" mode An important observation is that the drivers which don't currently request bridge event replays don't even have the switchdev_bridge_port_{offload,unoffload} calls placed in proper places right now. This was done to avoid unnecessary rework for drivers which might never even add support for this. For driver writers who wish to add replay support, this can be used as a tentative placement guide: https://patchwork.kernel.org/project/netdevbpf/patch/20210720134655.892334-11-vladimir.oltean@nxp.com/ Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:03 +08:00
err = nbp_switchdev_add(p, ppid, extack);
if (err)
return err;
err = nbp_switchdev_sync_objs(p, ctx, atomic_nb, blocking_nb, extack);
if (err)
goto out_switchdev_del;
return 0;
out_switchdev_del:
nbp_switchdev_del(p);
return err;
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
}
EXPORT_SYMBOL_GPL(switchdev_bridge_port_offload);
net: bridge: move the switchdev object replay helpers to "push" mode Starting with commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"), DSA has introduced some bridge helpers that replay switchdev events (FDB/MDB/VLAN additions and deletions) that can be lost by the switchdev drivers in a variety of circumstances: - an IP multicast group was host-joined on the bridge itself before any switchdev port joined the bridge, leading to the host MDB entries missing in the hardware database. - during the bridge creation process, the MAC address of the bridge was added to the FDB as an entry pointing towards the bridge device itself, but with no switchdev ports being part of the bridge yet, this local FDB entry would remain unknown to the switchdev hardware database. - a VLAN/FDB/MDB was added to a bridge port that is a LAG interface, before any switchdev port joined that LAG, leading to the hardware database missing those entries. - a switchdev port left a LAG that is a bridge port, while the LAG remained part of the bridge, and all FDB/MDB/VLAN entries remained installed in the hardware database of the switchdev port. Also, since commit 0d2cfbd41c4a ("net: bridge: ignore switchdev events for LAG ports which didn't request replay"), DSA introduced a method, based on a const void *ctx, to ensure that two switchdev ports under the same LAG that is a bridge port do not see the same MDB/VLAN entry being replayed twice by the bridge, once for every bridge port that joins the LAG. With so many ordering corner cases being possible, it seems unreasonable to expect a switchdev driver writer to get it right from the first try. Therefore, now that DSA has experimented with the bridge replay helpers for a little bit, we can move the code to the bridge driver where it is more readily available to all switchdev drivers. To convert the switchdev object replay helpers from "pull mode" (where the driver asks for them) to a "push mode" (where the bridge offers them automatically), the biggest problem is that the bridge needs to be aware when a switchdev port joins and leaves, even when the switchdev is only indirectly a bridge port (for example when the bridge port is a LAG upper of the switchdev). Luckily, we already have a hook for that, in the form of the newly introduced switchdev_bridge_port_offload() and switchdev_bridge_port_unoffload() calls. These offer a natural place for hooking the object addition and deletion replays. Extend the above 2 functions with: - pointers to the switchdev atomic notifier (for FDB replays) and the blocking notifier (for MDB and VLAN replays). - the "const void *ctx" argument required for drivers to be able to disambiguate between which port is targeted, when multiple ports are lowers of the same LAG that is a bridge port. Most of the drivers pass NULL to this argument, except the ones that support LAG offload and have the proper context check already in place in the switchdev blocking notifier handler. Also unexport the replay helpers, since nobody except the bridge calls them directly now. Note that: (a) we abuse the terminology slightly, because FDB entries are not "switchdev objects", but we count them as objects nonetheless. With no direct way to prove it, I think they are not modeled as switchdev objects because those can only be installed by the bridge to the hardware (as opposed to FDB entries which can be propagated in the other direction too). This is merely an abuse of terms, FDB entries are replayed too, despite not being objects. (b) the bridge does not attempt to sync port attributes to newly joined ports, just the countable stuff (the objects). The reason for this is simple: no universal and symmetric way to sync and unsync them is known. For example, VLAN filtering: what to do on unsync, disable or leave it enabled? Similarly, STP state, ageing timer, etc etc. What a switchdev port does when it becomes standalone again is not really up to the bridge's competence, and the driver should deal with it. On the other hand, replaying deletions of switchdev objects can be seen a matter of cleanup and therefore be treated by the bridge, hence this patch. We make the replay helpers opt-in for drivers, because they might not bring immediate benefits for them: - nbp_vlan_init() is called _after_ netdev_master_upper_dev_link(), so br_vlan_replay() should not do anything for the new drivers on which we call it. The existing drivers where there was even a slight possibility for there to exist a VLAN on a bridge port before they join it are already guarded against this: mlxsw and prestera deny joining LAG interfaces that are members of a bridge. - br_fdb_replay() should now notify of local FDB entries, but I patched all drivers except DSA to ignore these new entries in commit 2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB notifications"). Driver authors can lift this restriction as they wish, and when they do, they can also opt into the FDB replay functionality. - br_mdb_replay() should fix a real issue which is described in commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"). However most drivers do not offload the SWITCHDEV_OBJ_ID_HOST_MDB to see this issue: only cpsw and am65_cpsw offload this switchdev object, and I don't completely understand the way in which they offload this switchdev object anyway. So I'll leave it up to these drivers' respective maintainers to opt into br_mdb_replay(). So most of the drivers pass NULL notifier blocks for the replay helpers, except: - dpaa2-switch which was already acked/regression-tested with the helpers enabled (and there isn't much of a downside in having them) - ocelot which already had replay logic in "pull" mode - DSA which already had replay logic in "pull" mode An important observation is that the drivers which don't currently request bridge event replays don't even have the switchdev_bridge_port_{offload,unoffload} calls placed in proper places right now. This was done to avoid unnecessary rework for drivers which might never even add support for this. For driver writers who wish to add replay support, this can be used as a tentative placement guide: https://patchwork.kernel.org/project/netdevbpf/patch/20210720134655.892334-11-vladimir.oltean@nxp.com/ Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:03 +08:00
void switchdev_bridge_port_unoffload(struct net_device *brport_dev,
const void *ctx,
struct notifier_block *atomic_nb,
struct notifier_block *blocking_nb)
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
{
struct net_bridge_port *p;
ASSERT_RTNL();
p = br_port_get_rtnl(brport_dev);
if (!p)
return;
net: bridge: move the switchdev object replay helpers to "push" mode Starting with commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"), DSA has introduced some bridge helpers that replay switchdev events (FDB/MDB/VLAN additions and deletions) that can be lost by the switchdev drivers in a variety of circumstances: - an IP multicast group was host-joined on the bridge itself before any switchdev port joined the bridge, leading to the host MDB entries missing in the hardware database. - during the bridge creation process, the MAC address of the bridge was added to the FDB as an entry pointing towards the bridge device itself, but with no switchdev ports being part of the bridge yet, this local FDB entry would remain unknown to the switchdev hardware database. - a VLAN/FDB/MDB was added to a bridge port that is a LAG interface, before any switchdev port joined that LAG, leading to the hardware database missing those entries. - a switchdev port left a LAG that is a bridge port, while the LAG remained part of the bridge, and all FDB/MDB/VLAN entries remained installed in the hardware database of the switchdev port. Also, since commit 0d2cfbd41c4a ("net: bridge: ignore switchdev events for LAG ports which didn't request replay"), DSA introduced a method, based on a const void *ctx, to ensure that two switchdev ports under the same LAG that is a bridge port do not see the same MDB/VLAN entry being replayed twice by the bridge, once for every bridge port that joins the LAG. With so many ordering corner cases being possible, it seems unreasonable to expect a switchdev driver writer to get it right from the first try. Therefore, now that DSA has experimented with the bridge replay helpers for a little bit, we can move the code to the bridge driver where it is more readily available to all switchdev drivers. To convert the switchdev object replay helpers from "pull mode" (where the driver asks for them) to a "push mode" (where the bridge offers them automatically), the biggest problem is that the bridge needs to be aware when a switchdev port joins and leaves, even when the switchdev is only indirectly a bridge port (for example when the bridge port is a LAG upper of the switchdev). Luckily, we already have a hook for that, in the form of the newly introduced switchdev_bridge_port_offload() and switchdev_bridge_port_unoffload() calls. These offer a natural place for hooking the object addition and deletion replays. Extend the above 2 functions with: - pointers to the switchdev atomic notifier (for FDB replays) and the blocking notifier (for MDB and VLAN replays). - the "const void *ctx" argument required for drivers to be able to disambiguate between which port is targeted, when multiple ports are lowers of the same LAG that is a bridge port. Most of the drivers pass NULL to this argument, except the ones that support LAG offload and have the proper context check already in place in the switchdev blocking notifier handler. Also unexport the replay helpers, since nobody except the bridge calls them directly now. Note that: (a) we abuse the terminology slightly, because FDB entries are not "switchdev objects", but we count them as objects nonetheless. With no direct way to prove it, I think they are not modeled as switchdev objects because those can only be installed by the bridge to the hardware (as opposed to FDB entries which can be propagated in the other direction too). This is merely an abuse of terms, FDB entries are replayed too, despite not being objects. (b) the bridge does not attempt to sync port attributes to newly joined ports, just the countable stuff (the objects). The reason for this is simple: no universal and symmetric way to sync and unsync them is known. For example, VLAN filtering: what to do on unsync, disable or leave it enabled? Similarly, STP state, ageing timer, etc etc. What a switchdev port does when it becomes standalone again is not really up to the bridge's competence, and the driver should deal with it. On the other hand, replaying deletions of switchdev objects can be seen a matter of cleanup and therefore be treated by the bridge, hence this patch. We make the replay helpers opt-in for drivers, because they might not bring immediate benefits for them: - nbp_vlan_init() is called _after_ netdev_master_upper_dev_link(), so br_vlan_replay() should not do anything for the new drivers on which we call it. The existing drivers where there was even a slight possibility for there to exist a VLAN on a bridge port before they join it are already guarded against this: mlxsw and prestera deny joining LAG interfaces that are members of a bridge. - br_fdb_replay() should now notify of local FDB entries, but I patched all drivers except DSA to ignore these new entries in commit 2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB notifications"). Driver authors can lift this restriction as they wish, and when they do, they can also opt into the FDB replay functionality. - br_mdb_replay() should fix a real issue which is described in commit 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries"). However most drivers do not offload the SWITCHDEV_OBJ_ID_HOST_MDB to see this issue: only cpsw and am65_cpsw offload this switchdev object, and I don't completely understand the way in which they offload this switchdev object anyway. So I'll leave it up to these drivers' respective maintainers to opt into br_mdb_replay(). So most of the drivers pass NULL notifier blocks for the replay helpers, except: - dpaa2-switch which was already acked/regression-tested with the helpers enabled (and there isn't much of a downside in having them) - ocelot which already had replay logic in "pull" mode - DSA which already had replay logic in "pull" mode An important observation is that the drivers which don't currently request bridge event replays don't even have the switchdev_bridge_port_{offload,unoffload} calls placed in proper places right now. This was done to avoid unnecessary rework for drivers which might never even add support for this. For driver writers who wish to add replay support, this can be used as a tentative placement guide: https://patchwork.kernel.org/project/netdevbpf/patch/20210720134655.892334-11-vladimir.oltean@nxp.com/ Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:03 +08:00
nbp_switchdev_unsync_objs(p, ctx, atomic_nb, blocking_nb);
net: bridge: switchdev: let drivers inform which bridge ports are offloaded On reception of an skb, the bridge checks if it was marked as 'already forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it is, it assigns the source hardware domain of that skb based on the hardware domain of the ingress port. Then during forwarding, it enforces that the egress port must have a different hardware domain than the ingress one (this is done in nbp_switchdev_allowed_egress). Non-switchdev drivers don't report any physical switch id (neither through devlink nor .ndo_get_port_parent_id), therefore the bridge assigns them a hardware domain of 0, and packets coming from them will always have skb->offload_fwd_mark = 0. So there aren't any restrictions. Problems appear due to the fact that DSA would like to perform software fallback for bonding and team interfaces that the physical switch cannot offload. +-- br0 ---+ / / | \ / / | \ / | | bond0 / | | / \ swp0 swp1 swp2 swp3 swp4 There, it is desirable that the presence of swp3 and swp4 under a non-offloaded LAG does not preclude us from doing hardware bridging beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high enough that software bridging between {swp0,swp1,swp2} and bond0 is not impractical. But this creates an impossible paradox given the current way in which port hardware domains are assigned. When the driver receives a packet from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to something. - If we set it to 0, then the bridge will forward it towards swp1, swp2 and bond0. But the switch has already forwarded it towards swp1 and swp2 (not to bond0, remember, that isn't offloaded, so as far as the switch is concerned, ports swp3 and swp4 are not looking up the FDB, and the entire bond0 is a destination that is strictly behind the CPU). But we don't want duplicated traffic towards swp1 and swp2, so it's not ok to set skb->offload_fwd_mark = 0. - If we set it to 1, then the bridge will not forward the skb towards the ports with the same switchdev mark, i.e. not to swp1, swp2 and bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should have forwarded the skb there. So the real issue is that bond0 will be assigned the same hardware domain as {swp0,swp1,swp2}, because the function that assigns hardware domains to bridge ports, nbp_switchdev_add(), recurses through bond0's lower interfaces until it finds something that implements devlink (calls dev_get_port_parent_id with bool recurse = true). This is a problem because the fact that bond0 can be offloaded by swp3 and swp4 in our example is merely an assumption. A solution is to give the bridge explicit hints as to what hardware domain it should use for each port. Currently, the bridging offload is very 'silent': a driver registers a netdevice notifier, which is put on the netns's notifier chain, and which sniffs around for NETDEV_CHANGEUPPER events where the upper is a bridge, and the lower is an interface it knows about (one registered by this driver, normally). Then, from within that notifier, it does a bunch of stuff behind the bridge's back, without the bridge necessarily knowing that there's somebody offloading that port. It looks like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v call_netdevice_notifiers | v dsa_slave_netdevice_event | v oh, hey! it's for me! | v .port_bridge_join What we do to solve the conundrum is to be less silent, and change the switchdev drivers to present themselves to the bridge. Something like this: ip link set swp0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | hardware domain for v | this port, and zero dsa_slave_netdevice_event | if I got nothing. | | v | oh, hey! it's for me! | | | v | .port_bridge_join | | | +------------------------+ switchdev_bridge_port_offload(swp0, swp0) Then stacked interfaces (like bond0 on top of swp3/swp4) would be treated differently in DSA, depending on whether we can or cannot offload them. The offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge: Aye! I'll use this call_netdevice_notifiers ^ ppid as the | | switchdev mark for v | bond0. dsa_slave_netdevice_event | Coincidentally (or not), | | bond0 and swp0, swp1, swp2 v | all have the same switchdev hmm, it's not quite for me, | mark now, since the ASIC but my driver has already | is able to forward towards called .port_lag_join | all these ports in hw. for it, because I have | a port with dp->lag_dev == bond0. | | | v | .port_bridge_join | for swp3 and swp4 | | | +------------------------+ switchdev_bridge_port_offload(bond0, swp3) switchdev_bridge_port_offload(bond0, swp4) And the non-offload case: ip link set bond0 master br0 | v br_add_if() calls netdev_master_upper_dev_link() | v bridge waiting: call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload | | wasn't called, okay, I'll use a v | hwdom of zero for this one. dsa_slave_netdevice_event : Then packets received on swp0 will | : not be software-forwarded towards v : swp1, but they will towards bond0. it's not for me, but bond0 is an upper of swp3 and swp4, but their dp->lag_dev is NULL because they couldn't offload it. Basically we can draw the conclusion that the lowers of a bridge port can come and go, so depending on the configuration of lowers for a bridge port, it can dynamically toggle between offloaded and unoffloaded. Therefore, we need an equivalent switchdev_bridge_port_unoffload too. This patch changes the way any switchdev driver interacts with the bridge. From now on, everybody needs to call switchdev_bridge_port_offload and switchdev_bridge_port_unoffload, otherwise the bridge will treat the port as non-offloaded and allow software flooding to other ports from the same ASIC. Note that these functions lay the ground for a more complex handshake between switchdev drivers and the bridge in the future. For drivers that will request a replay of the switchdev objects when they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we place the call to switchdev_bridge_port_unoffload() strategically inside the NETDEV_PRECHANGEUPPER notifier's code path, and not inside NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers need the netdev adjacency lists to be valid, and that is only true in NETDEV_PRECHANGEUPPER. Cc: Vadym Kochan <vkochan@marvell.com> Cc: Taras Chornyi <tchornyi@marvell.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Lars Povlsen <lars.povlsen@microchip.com> Cc: Steen Hegelund <Steen.Hegelund@microchip.com> Cc: UNGLinuxDriver@microchip.com Cc: Claudiu Manoil <claudiu.manoil@nxp.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:24:01 +08:00
nbp_switchdev_del(p);
}
EXPORT_SYMBOL_GPL(switchdev_bridge_port_unoffload);