Commit Graph

196 Commits

Author SHA1 Message Date
Vivien Didelot 76e398a627 net: dsa: use switchdev obj for VLAN add/del ops
Simplify DSA by pushing the switchdev objects for VLAN add and delete
operations down to its drivers. Currently only mv88e6xxx is affected.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-01 15:56:11 -05:00
Vivien Didelot 1a49a2fbf8 net: dsa: remove port_fdb_getnext
No driver implements port_fdb_getnext anymore, and port_fdb_dump is
preferred anyway, so remove this function from DSA.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-22 07:38:45 -07:00
Vivien Didelot ea70ba9806 net: dsa: add port_fdb_dump function
Not all switch chips support a Get Next operation to iterate on its FDB.
So add a more simple port_fdb_dump function for them.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-22 07:38:35 -07:00
David S. Miller 26440c835f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/usb/asix_common.c
	net/ipv4/inet_connection_sock.c
	net/switchdev/switchdev.c

In the inet_connection_sock.c case the request socket hashing scheme
is completely different in net-next.

The other two conflicts were overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-20 06:08:27 -07:00
Jiri Pirko 850d0cbc91 switchdev: remove pointers from switchdev objects
When object is used in deferred work, we cannot use pointers in
switchdev object structures because the memory they point at may be already
used by someone else. So rather do local copy of the value.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-15 06:09:49 -07:00
Jiri Pirko f7fadf3047 switchdev: make struct switchdev_attr parameter const for attr_set calls
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-15 06:09:46 -07:00
Vivien Didelot efd29b3d82 net: dsa: do not warn unsupported bridge ops
A DSA driver may not provide the port_join_bridge and port_leave_bridge
functions, so don't warn in such case.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-13 04:26:30 -07:00
Vivien Didelot 8057b3e7a1 net: dsa: use switchdev obj in port_fdb_del
For consistency with the FDB add operation, propagate the
switchdev_obj_port_fdb structure in the DSA drivers.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-11 05:28:52 -07:00
Vivien Didelot 1f36faf269 net: dsa: push prepare phase in port_fdb_add
Now that the prepare phase is pushed down to the DSA drivers, propagate
it to the port_fdb_add function.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-11 05:28:50 -07:00
Vivien Didelot 146a32067b net: dsa: add port_fdb_prepare
Push the prepare phase for FDB operations down to the DSA drivers, with
a new port_fdb_prepare function. Currently only mv88e6xxx is affected.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-11 05:28:49 -07:00
Neil Armstrong 4d7f3e757c net: dsa: exit probe if no switch were found
If no switch were found in dsa_setup_dst, return -ENODEV and
exit the dsa_probe cleanly.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:56:11 -07:00
Neil Armstrong d4ac35d6ed net: dsa: switch to devm_ calls and remove kfree calls
Now the kfree calls exists in the the remove functions, remove them in all
places except the of_probe functions and replace allocation calls
with their devm_ counterparts.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:56:09 -07:00
Neil Armstrong cbc5d90b37 net: dsa: complete dsa_switch_destroy
When unbinding dsa, complete the dsa_switch_destroy to unregister the
fixed link phy then cleanly unregister and destroy the net devices.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:56:08 -07:00
Neil Armstrong e410ddb89e net: dsa: add missing dsa_switch mdiobus remove
To prevent memory leakage on unbinding, add missing mdiobus unregister
and unallocation calls.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:56:07 -07:00
Neil Armstrong 1023d2ec1e net: dsa: add missing kfree on remove
To prevent memory leakage on unbinding, add missing kfree calls.
Includes minor cosmetic change to make patch clean.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:56:06 -07:00
Russell King d25b8e7429 net: dsa: better error reporting
Add additional error reporting to the generic DSA code, so it's easier
to debug when things go wrong.  This was useful when initially bringing
up 88e6176 on a new board.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 02:58:49 -07:00
Jiri Pirko 9e8f4a548a switchdev: push object ID back to object structure
Suggested-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:49:40 -07:00
Jiri Pirko 648b4a995a switchdev: bring back switchdev_obj and use it as a generic object param
Replace "void *obj" with a generic structure. Introduce couple of
helpers along that.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:49:39 -07:00
Jiri Pirko 52ba57cfdc switchdev: rename switchdev_obj_fdb to switchdev_obj_port_fdb
Make the struct name in sync with object id name.

Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:49:39 -07:00
Jiri Pirko 8f24f3095d switchdev: rename switchdev_obj_vlan to switchdev_obj_port_vlan
Make the struct name in sync with object id name.

Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:49:38 -07:00
Jiri Pirko 1f86839874 switchdev: rename SWITCHDEV_ATTR_* enum values to SWITCHDEV_ATTR_ID_*
To be aligned with obj.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:49:37 -07:00
Jiri Pirko 57d80838da switchdev: rename SWITCHDEV_OBJ_* enum values to SWITCHDEV_OBJ_ID_*
Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:49:36 -07:00
Vivien Didelot 57a47532c4 net: dsa: fix preparation of a port STP update
Because of the default 0 value of ret in dsa_slave_port_attr_set, a
driver may return -EOPNOTSUPP from the commit phase of a STP state,
which triggers a WARN() from switchdev.

This happened on a 6185 switch which does not support hardware bridging.

Fixes: 3563606258 ("switchdev: convert STP update to switchdev attr set")
Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 21:36:01 -07:00
Vivien Didelot b8d866ac6a net: dsa: fix preparation of a port STP update
Because of the default 0 value of ret in dsa_slave_port_attr_set, a
driver may return -EOPNOTSUPP from the commit phase of a STP state,
which triggers a WARN() from switchdev.

This happened on a 6185 switch which does not support hardware bridging.

Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 21:35:06 -07:00
Vivien Didelot ab06900230 net: switchdev: abstract object in add/del ops
Similar to the notifier_call callback of a notifier_block, change the
function signature of switchdev add and del operations to:

    int switchdev_port_obj_add/del(struct net_device *dev,
                                   enum switchdev_obj_id id, void *obj);

This allows the caller to pass a specific switchdev_obj_* structure
instead of the generic switchdev_obj one.

Drivers implementation of these operations and switchdev have been
changed accordingly.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 21:31:59 -07:00
Vivien Didelot 25f07adc47 net: switchdev: pass callback to dump operation
Similar to the notifier_call callback of a notifier_block, change the
function signature of switchdev dump operation to:

    int switchdev_port_obj_dump(struct net_device *dev,
                                enum switchdev_obj_id id, void *obj,
                                int (*cb)(void *obj));

This allows the caller to pass and expect back a specific
switchdev_obj_* structure instead of the generic switchdev_obj one.

Drivers implementation of dump operation can now expect this specific
structure and call the callback with it. Drivers have been changed
accordingly.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 21:31:59 -07:00
Vivien Didelot 03d5fb1862 net: switchdev: remove dev from switchdev_obj cb
The net_device associated to a dump operation does not have to be passed
to the callback. switchdev stores it in a superset struct, if needed.

Also some drivers (such as DSA drivers) may not have easy access to it.

This will simplify pushing the callback function down to the drivers.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 21:31:59 -07:00
David S. Miller 4963ed48f2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv4/arp.c

The net/ipv4/arp.c conflict was one commit adding a new
local variable while another commit was deleting one.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-26 16:08:27 -07:00
Florian Fainelli f37db85d0c net: dsa: Set a "dsa" device_type
Provide a device_type information for slave network devices created by
DSA, this is useful for user-space application to easily locate/search
for devices of a specific kind.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 12:25:16 -07:00
Russell King 9861f72074 net: fix net_device refcounting
of_find_net_device_by_node() uses class_find_device() internally to
lookup the corresponding network device.  class_find_device() returns
a reference to the embedded struct device, with its refcount
incremented.

Add a comment to the definition in net/core/net-sysfs.c indicating the
need to drop this refcount, and fix the DSA code to drop this refcount
when the OF-generated platform data is cleaned up and freed.  Also
arrange for the ref to be dropped when handling errors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 23:04:53 -07:00
Russell King e496ae690b net: dsa: fix of_mdio_find_bus() device refcount leak
Current users of of_mdio_find_bus() leak a struct device refcount, as
they fail to clean up the reference obtained inside class_find_device().

Fix the DSA code to properly refcount the returned MDIO bus by:
1. taking a reference on the struct device whenever we assign it to
   pd->chip[x].host_dev.
2. dropping the reference when we overwrite the existing reference.
3. dropping the reference when we free the data structure.
4. dropping the initial reference we obtained after setting up the
   platform data structure, or on failure.

In step 2 above, where we obtain a new MDIO bus, there is no need to
take a reference on it as we would only have to drop it immediately
after assignment again, iow:

	put_device(cd->host_dev);	/* drop original assignment ref */
	cd->host_dev = get_device(&mdio_bus_switch->dev); /* get our ref */
	put_device(&mdio_bus_switch->dev); /* drop of_mdio_find_bus ref */

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 23:04:52 -07:00
Jiri Pirko 79a62eb22a dsa: use prepare/commit switchdev transaction helpers
The enum is going to disappear, use the helpers instead.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 22:59:22 -07:00
Jiri Pirko f8db83486e switchdev: move transaction phase enum under transaction structure
Before it disappears completely, move transaction phase enum under
transaction structure and make attr/obj structures a bit cleaner.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 22:59:21 -07:00
Jiri Pirko 7ea6eb3f56 switchdev: introduce transaction item queue for attr_set and obj_add
Now, the memory allocation in prepare/commit state is done separatelly
in each driver (rocker). Introduce the similar mechanism in generic
switchdev code, in form of queue. That can be used not only for memory
allocations, but also for different items. Abort item destruction
is handled as well.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 22:59:21 -07:00
Jiri Pirko 69f5df491e switchdev: rename "trans" to "trans_ph".
This is temporary, name "trans" will be used for something else and
"trans_ph" will eventually disappear.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 22:59:21 -07:00
Neil Armstrong fbd03513bf net: dsa: Fix Marvell Egress Trailer check
The Marvell Egress rx trailer check must be fixed to
correctly detect bad bits in the third byte of the
Eggress trailer as described in the Table 28 of the
88E6060 datasheet.
The current code incorrectly omits to check the third
byte and checks the fourth byte twice.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-22 17:37:03 -07:00
Andrew Lunn e448534668 net: dsa: Allow DSA and CPU ports to have a phy-mode property
It can be useful for DSA and CPU ports to have a phy-mode property, in
particular to specify RGMII delays. Parse the property and set it in
the fixed-link phydev.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-31 14:48:02 -07:00
Andrew Lunn 39b0c70519 net: dsa: Allow configuration of CPU & DSA port speeds/duplex
By default, DSA and CPU ports are configured to the maximum speed the
switch supports. However there can be use cases where the peer devices
port is slower. Allow a fixed-link property to be used with the DSA
and CPU port in the device tree, and use this information to configure
the port.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-31 14:48:02 -07:00
Andrew Lunn 1e72e6f885 net: dsa: Allow multi hop routes to be expressed
With more than two switches in a hierarchy, it becomes necessary to
describe multi-hop routes between switches. The current binding does
not allow this, although the older platform_data did. Extend the link
property to be a list rather than a single phandle to a remote switch.
It is then possible to express that a port should be used to reach
more than one switch and the switch maybe more than one hop away.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-18 14:17:21 -07:00
Phil Sutter 0a5f107b67 net: dsa: convert to using IFF_NO_QUEUE
Signed-off-by: Phil Sutter <phil@nwl.cc>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-18 11:55:06 -07:00
Vivien Didelot 1114953615 net: dsa: add support for switchdev VLAN objects
Add new functions in DSA drivers to access hardware VLAN entries through
SWITCHDEV_OBJ_PORT_VLAN objects:

 - port_pvid_get() and vlan_getnext() to dump a VLAN
 - port_vlan_del() to exclude a port from a VLAN
 - port_pvid_set() and port_vlan_add() to join a port to a VLAN

The DSA infrastructure will ensure that each VLAN of the given range
does not already belong to another bridge. If it does, it will fallback
to software VLAN and won't program the hardware.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-13 21:31:12 -07:00
David S. Miller 182ad468e7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/cavium/Kconfig

The cavium conflict was overlapping dependency
changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-13 16:23:11 -07:00
Florian Fainelli 211c504a44 net: dsa: Do not override PHY interface if already configured
In case we need to divert reads/writes using the slave MII bus, we may have
already fetched a valid PHY interface property from Device Tree, and that
mode is used by the PHY driver to make configuration decisions.

If we could not fetch the "phy-mode" property, we will assign p->phy_interface
to PHY_INTERFACE_MODE_NA, such that we can actually check for that condition as
to whether or not we should override the interface value.

Fixes: 19334920ea ("net: dsa: Set valid phy interface type")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-12 14:29:50 -07:00
Vivien Didelot ba14d9eb19 net: dsa: add support for switchdev FDB objects
Implement the switchdev_port_obj_{add,del,dump} functions in DSA to
support the SWITCHDEV_OBJ_PORT_FDB objects.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-11 12:03:19 -07:00
Vivien Didelot 2a778e1b58 net: dsa: change FDB routines prototypes
Change the prototype of port_getnext to include a vid parameter.

This is necessary to introduce the support for VLAN.

Also rename the fdb_{add,del,getnext} function pointers to
port_fdb_{add,del,getnext} since they are specific to a given port.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-11 12:03:19 -07:00
David S. Miller cdf0969763 Revert "Merge branch 'mv88e6xxx-switchdev-fdb'"
This reverts commit f1d5ca4344, reversing
changes made to 4933d85c51.

I applied v2 instead of v3.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-11 12:00:37 -07:00
Andrew Lunn 6bc6d0a881 dsa: Support multiple MDIO busses
When using a cluster of switches, some topologies will have an MDIO
bus per switch, not one for the whole cluster. Allow this to be
represented in the device tree, by adding an optional mii-bus property
at the switch level. The old platform_device method of instantiation
supports this already, so only the device tree binding needs extending
with an additional optional phandle.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-10 14:25:02 -07:00
Vivien Didelot 55045ddded net: dsa: add support for switchdev FDB objects
Remove the fdb_{add,del,getnext} function pointer in favor of new
port_fdb_{add,del,getnext}.

Implement the switchdev_port_obj_{add,del,dump} functions in DSA to
support the SWITCHDEV_OBJ_PORT_FDB objects.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-09 22:48:09 -07:00
Florian Fainelli 04ff53f96a net: dsa: Add netconsole support
Add support for using DSA slave network devices with netconsole, which
requires us to allocate and free custom netpoll instances and invoke the
parent network device poll controller callback.

In order for netconsole to work, we need to construct the DSA tag, but
not queue the skb for transmission on the master network device xmit
function.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 15:45:37 -07:00
Florian Fainelli 4ed70ce9f0 net: dsa: Refactor transmit path to eliminate duplication
All tagging protocols do the same thing: increment device statistics,
make room for the tag to be inserted, create the tag, invoke the parent
network device transmit function.

In order to prepare for adding netpoll support, which requires the tag
creation, but not using the parent network device transmit function, do
some little refactoring which eliminates duplication between the 4
tagging protocols supported.

We need to return a sk_buff pointer back to the caller because the tag
specific transmit function may have to reallocate the original skb (e.g:
tag_trailer.c) and this is the one we should be transmitting, not the
original sk_buff we were passed.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 15:45:37 -07:00