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linux-sg2042/drivers/hv/channel_mgmt.c

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/*
* Copyright (c) 2009, Microsoft Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
* Authors:
* Haiyang Zhang <haiyangz@microsoft.com>
* Hank Janssen <hjanssen@microsoft.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/hyperv.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
static void init_vp_index(struct vmbus_channel *channel, u16 dev_type);
static const struct vmbus_device vmbus_devs[] = {
/* IDE */
{ .dev_type = HV_IDE,
HV_IDE_GUID,
.perf_device = true,
},
/* SCSI */
{ .dev_type = HV_SCSI,
HV_SCSI_GUID,
.perf_device = true,
},
/* Fibre Channel */
{ .dev_type = HV_FC,
HV_SYNTHFC_GUID,
.perf_device = true,
},
/* Synthetic NIC */
{ .dev_type = HV_NIC,
HV_NIC_GUID,
.perf_device = true,
},
/* Network Direct */
{ .dev_type = HV_ND,
HV_ND_GUID,
.perf_device = true,
},
/* PCIE */
{ .dev_type = HV_PCIE,
HV_PCIE_GUID,
.perf_device = true,
},
/* Synthetic Frame Buffer */
{ .dev_type = HV_FB,
HV_SYNTHVID_GUID,
.perf_device = false,
},
/* Synthetic Keyboard */
{ .dev_type = HV_KBD,
HV_KBD_GUID,
.perf_device = false,
},
/* Synthetic MOUSE */
{ .dev_type = HV_MOUSE,
HV_MOUSE_GUID,
.perf_device = false,
},
/* KVP */
{ .dev_type = HV_KVP,
HV_KVP_GUID,
.perf_device = false,
},
/* Time Synch */
{ .dev_type = HV_TS,
HV_TS_GUID,
.perf_device = false,
},
/* Heartbeat */
{ .dev_type = HV_HB,
HV_HEART_BEAT_GUID,
.perf_device = false,
},
/* Shutdown */
{ .dev_type = HV_SHUTDOWN,
HV_SHUTDOWN_GUID,
.perf_device = false,
},
/* File copy */
{ .dev_type = HV_FCOPY,
HV_FCOPY_GUID,
.perf_device = false,
},
/* Backup */
{ .dev_type = HV_BACKUP,
HV_VSS_GUID,
.perf_device = false,
},
/* Dynamic Memory */
{ .dev_type = HV_DM,
HV_DM_GUID,
.perf_device = false,
},
/* Unknown GUID */
{ .dev_type = HV_UNKNOWN,
.perf_device = false,
},
};
static const struct {
uuid_le guid;
} vmbus_unsupported_devs[] = {
{ HV_AVMA1_GUID },
{ HV_AVMA2_GUID },
{ HV_RDV_GUID },
};
/*
* The rescinded channel may be blocked waiting for a response from the host;
* take care of that.
*/
static void vmbus_rescind_cleanup(struct vmbus_channel *channel)
{
struct vmbus_channel_msginfo *msginfo;
unsigned long flags;
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
msglistentry) {
if (msginfo->waiting_channel == channel) {
complete(&msginfo->waitevent);
break;
}
}
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}
static bool is_unsupported_vmbus_devs(const uuid_le *guid)
{
int i;
for (i = 0; i < ARRAY_SIZE(vmbus_unsupported_devs); i++)
if (!uuid_le_cmp(*guid, vmbus_unsupported_devs[i].guid))
return true;
return false;
}
static u16 hv_get_dev_type(const struct vmbus_channel *channel)
{
const uuid_le *guid = &channel->offermsg.offer.if_type;
u16 i;
if (is_hvsock_channel(channel) || is_unsupported_vmbus_devs(guid))
return HV_UNKNOWN;
for (i = HV_IDE; i < HV_UNKNOWN; i++) {
if (!uuid_le_cmp(*guid, vmbus_devs[i].guid))
return i;
}
pr_info("Unknown GUID: %pUl\n", guid);
return i;
}
/**
* vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
* @icmsghdrp: Pointer to msg header structure
* @icmsg_negotiate: Pointer to negotiate message structure
* @buf: Raw buffer channel data
*
* @icmsghdrp is of type &struct icmsg_hdr.
* Set up and fill in default negotiate response message.
*
* The fw_version and fw_vercnt specifies the framework version that
* we can support.
*
* The srv_version and srv_vercnt specifies the service
* versions we can support.
*
* Versions are given in decreasing order.
*
* nego_fw_version and nego_srv_version store the selected protocol versions.
*
* Mainly used by Hyper-V drivers.
*/
bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
u8 *buf, const int *fw_version, int fw_vercnt,
const int *srv_version, int srv_vercnt,
int *nego_fw_version, int *nego_srv_version)
{
int icframe_major, icframe_minor;
int icmsg_major, icmsg_minor;
int fw_major, fw_minor;
int srv_major, srv_minor;
int i, j;
bool found_match = false;
struct icmsg_negotiate *negop;
icmsghdrp->icmsgsize = 0x10;
negop = (struct icmsg_negotiate *)&buf[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
icframe_major = negop->icframe_vercnt;
icframe_minor = 0;
icmsg_major = negop->icmsg_vercnt;
icmsg_minor = 0;
/*
* Select the framework version number we will
* support.
*/
for (i = 0; i < fw_vercnt; i++) {
fw_major = (fw_version[i] >> 16);
fw_minor = (fw_version[i] & 0xFFFF);
for (j = 0; j < negop->icframe_vercnt; j++) {
if ((negop->icversion_data[j].major == fw_major) &&
(negop->icversion_data[j].minor == fw_minor)) {
icframe_major = negop->icversion_data[j].major;
icframe_minor = negop->icversion_data[j].minor;
found_match = true;
break;
}
}
if (found_match)
break;
}
if (!found_match)
goto fw_error;
found_match = false;
for (i = 0; i < srv_vercnt; i++) {
srv_major = (srv_version[i] >> 16);
srv_minor = (srv_version[i] & 0xFFFF);
for (j = negop->icframe_vercnt;
(j < negop->icframe_vercnt + negop->icmsg_vercnt);
j++) {
if ((negop->icversion_data[j].major == srv_major) &&
(negop->icversion_data[j].minor == srv_minor)) {
icmsg_major = negop->icversion_data[j].major;
icmsg_minor = negop->icversion_data[j].minor;
found_match = true;
break;
}
}
if (found_match)
break;
}
/*
* Respond with the framework and service
* version numbers we can support.
*/
fw_error:
if (!found_match) {
negop->icframe_vercnt = 0;
negop->icmsg_vercnt = 0;
} else {
negop->icframe_vercnt = 1;
negop->icmsg_vercnt = 1;
}
if (nego_fw_version)
*nego_fw_version = (icframe_major << 16) | icframe_minor;
if (nego_srv_version)
*nego_srv_version = (icmsg_major << 16) | icmsg_minor;
negop->icversion_data[0].major = icframe_major;
negop->icversion_data[0].minor = icframe_minor;
negop->icversion_data[1].major = icmsg_major;
negop->icversion_data[1].minor = icmsg_minor;
return found_match;
}
EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
/*
* alloc_channel - Allocate and initialize a vmbus channel object
*/
static struct vmbus_channel *alloc_channel(void)
{
struct vmbus_channel *channel;
channel = kzalloc(sizeof(*channel), GFP_ATOMIC);
if (!channel)
return NULL;
spin_lock_init(&channel->lock);
INIT_LIST_HEAD(&channel->sc_list);
INIT_LIST_HEAD(&channel->percpu_list);
tasklet_init(&channel->callback_event,
vmbus_on_event, (unsigned long)channel);
return channel;
}
/*
* free_channel - Release the resources used by the vmbus channel object
*/
static void free_channel(struct vmbus_channel *channel)
{
tasklet_kill(&channel->callback_event);
kfree_rcu(channel, rcu);
}
static void percpu_channel_enq(void *arg)
{
struct vmbus_channel *channel = arg;
struct hv_per_cpu_context *hv_cpu
= this_cpu_ptr(hv_context.cpu_context);
list_add_tail_rcu(&channel->percpu_list, &hv_cpu->chan_list);
}
static void percpu_channel_deq(void *arg)
{
struct vmbus_channel *channel = arg;
list_del_rcu(&channel->percpu_list);
}
static void vmbus_release_relid(u32 relid)
{
struct vmbus_channel_relid_released msg;
memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
msg.child_relid = relid;
msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released),
true);
}
void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
{
unsigned long flags;
struct vmbus_channel *primary_channel;
BUG_ON(!channel->rescind);
BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex));
if (channel->target_cpu != get_cpu()) {
put_cpu();
smp_call_function_single(channel->target_cpu,
percpu_channel_deq, channel, true);
} else {
percpu_channel_deq(channel);
put_cpu();
}
if (channel->primary_channel == NULL) {
list_del(&channel->listentry);
primary_channel = channel;
} else {
primary_channel = channel->primary_channel;
spin_lock_irqsave(&primary_channel->lock, flags);
list_del(&channel->sc_list);
primary_channel->num_sc--;
spin_unlock_irqrestore(&primary_channel->lock, flags);
}
/*
* We need to free the bit for init_vp_index() to work in the case
* of sub-channel, when we reload drivers like hv_netvsc.
*/
if (channel->affinity_policy == HV_LOCALIZED)
cpumask_clear_cpu(channel->target_cpu,
&primary_channel->alloced_cpus_in_node);
vmbus_release_relid(relid);
free_channel(channel);
}
void vmbus_free_channels(void)
{
struct vmbus_channel *channel, *tmp;
list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list,
listentry) {
/* hv_process_channel_removal() needs this */
channel->rescind = true;
vmbus_device_unregister(channel->device_obj);
}
}
/*
* vmbus_process_offer - Process the offer by creating a channel/device
* associated with this offer
*/
static void vmbus_process_offer(struct vmbus_channel *newchannel)
{
struct vmbus_channel *channel;
bool fnew = true;
unsigned long flags;
u16 dev_type;
int ret;
/* Make sure this is a new offer */
mutex_lock(&vmbus_connection.channel_mutex);
/*
* Now that we have acquired the channel_mutex,
* we can release the potentially racing rescind thread.
*/
atomic_dec(&vmbus_connection.offer_in_progress);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
if (!uuid_le_cmp(channel->offermsg.offer.if_type,
newchannel->offermsg.offer.if_type) &&
!uuid_le_cmp(channel->offermsg.offer.if_instance,
newchannel->offermsg.offer.if_instance)) {
fnew = false;
break;
}
}
if (fnew)
list_add_tail(&newchannel->listentry,
&vmbus_connection.chn_list);
mutex_unlock(&vmbus_connection.channel_mutex);
if (!fnew) {
/*
* Check to see if this is a sub-channel.
*/
if (newchannel->offermsg.offer.sub_channel_index != 0) {
/*
* Process the sub-channel.
*/
newchannel->primary_channel = channel;
spin_lock_irqsave(&channel->lock, flags);
list_add_tail(&newchannel->sc_list, &channel->sc_list);
channel->num_sc++;
spin_unlock_irqrestore(&channel->lock, flags);
} else {
goto err_free_chan;
}
}
dev_type = hv_get_dev_type(newchannel);
init_vp_index(newchannel, dev_type);
if (newchannel->target_cpu != get_cpu()) {
put_cpu();
smp_call_function_single(newchannel->target_cpu,
percpu_channel_enq,
newchannel, true);
} else {
percpu_channel_enq(newchannel);
put_cpu();
}
/*
* This state is used to indicate a successful open
* so that when we do close the channel normally, we
* can cleanup properly
*/
newchannel->state = CHANNEL_OPEN_STATE;
if (!fnew) {
if (channel->sc_creation_callback != NULL)
channel->sc_creation_callback(newchannel);
return;
}
/*
* Start the process of binding this offer to the driver
* We need to set the DeviceObject field before calling
* vmbus_child_dev_add()
*/
newchannel->device_obj = vmbus_device_create(
&newchannel->offermsg.offer.if_type,
&newchannel->offermsg.offer.if_instance,
newchannel);
if (!newchannel->device_obj)
goto err_deq_chan;
newchannel->device_obj->device_id = dev_type;
/*
* Add the new device to the bus. This will kick off device-driver
* binding which eventually invokes the device driver's AddDevice()
* method.
*/
ret = vmbus_device_register(newchannel->device_obj);
if (ret != 0) {
pr_err("unable to add child device object (relid %d)\n",
newchannel->offermsg.child_relid);
kfree(newchannel->device_obj);
goto err_deq_chan;
}
newchannel->probe_done = true;
return;
err_deq_chan:
mutex_lock(&vmbus_connection.channel_mutex);
list_del(&newchannel->listentry);
mutex_unlock(&vmbus_connection.channel_mutex);
if (newchannel->target_cpu != get_cpu()) {
put_cpu();
smp_call_function_single(newchannel->target_cpu,
percpu_channel_deq, newchannel, true);
} else {
percpu_channel_deq(newchannel);
put_cpu();
}
vmbus_release_relid(newchannel->offermsg.child_relid);
err_free_chan:
free_channel(newchannel);
}
/*
* We use this state to statically distribute the channel interrupt load.
*/
static int next_numa_node_id;
/*
* Starting with Win8, we can statically distribute the incoming
* channel interrupt load by binding a channel to VCPU.
* We do this in a hierarchical fashion:
* First distribute the primary channels across available NUMA nodes
* and then distribute the subchannels amongst the CPUs in the NUMA
* node assigned to the primary channel.
*
* For pre-win8 hosts or non-performance critical channels we assign the
* first CPU in the first NUMA node.
*/
static void init_vp_index(struct vmbus_channel *channel, u16 dev_type)
{
u32 cur_cpu;
bool perf_chn = vmbus_devs[dev_type].perf_device;
struct vmbus_channel *primary = channel->primary_channel;
int next_node;
struct cpumask available_mask;
struct cpumask *alloced_mask;
if ((vmbus_proto_version == VERSION_WS2008) ||
(vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) {
/*
* Prior to win8, all channel interrupts are
* delivered on cpu 0.
* Also if the channel is not a performance critical
* channel, bind it to cpu 0.
*/
channel->numa_node = 0;
channel->target_cpu = 0;
channel->target_vp = hv_cpu_number_to_vp_number(0);
return;
}
/*
* Based on the channel affinity policy, we will assign the NUMA
* nodes.
*/
if ((channel->affinity_policy == HV_BALANCED) || (!primary)) {
while (true) {
next_node = next_numa_node_id++;
if (next_node == nr_node_ids) {
next_node = next_numa_node_id = 0;
continue;
}
if (cpumask_empty(cpumask_of_node(next_node)))
continue;
break;
}
channel->numa_node = next_node;
primary = channel;
}
alloced_mask = &hv_context.hv_numa_map[primary->numa_node];
if (cpumask_weight(alloced_mask) ==
cpumask_weight(cpumask_of_node(primary->numa_node))) {
/*
* We have cycled through all the CPUs in the node;
* reset the alloced map.
*/
cpumask_clear(alloced_mask);
}
cpumask_xor(&available_mask, alloced_mask,
cpumask_of_node(primary->numa_node));
cur_cpu = -1;
if (primary->affinity_policy == HV_LOCALIZED) {
/*
* Normally Hyper-V host doesn't create more subchannels
* than there are VCPUs on the node but it is possible when not
* all present VCPUs on the node are initialized by guest.
* Clear the alloced_cpus_in_node to start over.
*/
if (cpumask_equal(&primary->alloced_cpus_in_node,
cpumask_of_node(primary->numa_node)))
cpumask_clear(&primary->alloced_cpus_in_node);
}
while (true) {
cur_cpu = cpumask_next(cur_cpu, &available_mask);
if (cur_cpu >= nr_cpu_ids) {
cur_cpu = -1;
cpumask_copy(&available_mask,
cpumask_of_node(primary->numa_node));
continue;
}
if (primary->affinity_policy == HV_LOCALIZED) {
/*
* NOTE: in the case of sub-channel, we clear the
* sub-channel related bit(s) in
* primary->alloced_cpus_in_node in
* hv_process_channel_removal(), so when we
* reload drivers like hv_netvsc in SMP guest, here
* we're able to re-allocate
* bit from primary->alloced_cpus_in_node.
*/
if (!cpumask_test_cpu(cur_cpu,
&primary->alloced_cpus_in_node)) {
cpumask_set_cpu(cur_cpu,
&primary->alloced_cpus_in_node);
cpumask_set_cpu(cur_cpu, alloced_mask);
break;
}
} else {
cpumask_set_cpu(cur_cpu, alloced_mask);
break;
}
}
channel->target_cpu = cur_cpu;
channel->target_vp = hv_cpu_number_to_vp_number(cur_cpu);
}
static void vmbus_wait_for_unload(void)
{
int cpu;
void *page_addr;
struct hv_message *msg;
struct vmbus_channel_message_header *hdr;
u32 message_type;
/*
* CHANNELMSG_UNLOAD_RESPONSE is always delivered to the CPU which was
* used for initial contact or to CPU0 depending on host version. When
* we're crashing on a different CPU let's hope that IRQ handler on
* the cpu which receives CHANNELMSG_UNLOAD_RESPONSE is still
* functional and vmbus_unload_response() will complete
* vmbus_connection.unload_event. If not, the last thing we can do is
* read message pages for all CPUs directly.
*/
while (1) {
if (completion_done(&vmbus_connection.unload_event))
break;
for_each_online_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
page_addr = hv_cpu->synic_message_page;
msg = (struct hv_message *)page_addr
+ VMBUS_MESSAGE_SINT;
message_type = READ_ONCE(msg->header.message_type);
if (message_type == HVMSG_NONE)
continue;
hdr = (struct vmbus_channel_message_header *)
msg->u.payload;
if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE)
complete(&vmbus_connection.unload_event);
vmbus_signal_eom(msg, message_type);
}
mdelay(10);
}
/*
* We're crashing and already got the UNLOAD_RESPONSE, cleanup all
* maybe-pending messages on all CPUs to be able to receive new
* messages after we reconnect.
*/
for_each_online_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
page_addr = hv_cpu->synic_message_page;
msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
msg->header.message_type = HVMSG_NONE;
}
}
/*
* vmbus_unload_response - Handler for the unload response.
*/
static void vmbus_unload_response(struct vmbus_channel_message_header *hdr)
{
/*
* This is a global event; just wakeup the waiting thread.
* Once we successfully unload, we can cleanup the monitor state.
*/
complete(&vmbus_connection.unload_event);
}
void vmbus_initiate_unload(bool crash)
{
struct vmbus_channel_message_header hdr;
/* Pre-Win2012R2 hosts don't support reconnect */
if (vmbus_proto_version < VERSION_WIN8_1)
return;
init_completion(&vmbus_connection.unload_event);
memset(&hdr, 0, sizeof(struct vmbus_channel_message_header));
hdr.msgtype = CHANNELMSG_UNLOAD;
vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header),
!crash);
/*
* vmbus_initiate_unload() is also called on crash and the crash can be
* happening in an interrupt context, where scheduling is impossible.
*/
if (!crash)
wait_for_completion(&vmbus_connection.unload_event);
else
vmbus_wait_for_unload();
}
/*
* vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
*
*/
static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
{
struct vmbus_channel_offer_channel *offer;
struct vmbus_channel *newchannel;
offer = (struct vmbus_channel_offer_channel *)hdr;
/* Allocate the channel object and save this offer. */
newchannel = alloc_channel();
if (!newchannel) {
vmbus_release_relid(offer->child_relid);
atomic_dec(&vmbus_connection.offer_in_progress);
pr_err("Unable to allocate channel object\n");
return;
}
/*
* Setup state for signalling the host.
*/
newchannel->sig_event = VMBUS_EVENT_CONNECTION_ID;
if (vmbus_proto_version != VERSION_WS2008) {
newchannel->is_dedicated_interrupt =
(offer->is_dedicated_interrupt != 0);
newchannel->sig_event = offer->connection_id;
}
memcpy(&newchannel->offermsg, offer,
sizeof(struct vmbus_channel_offer_channel));
newchannel->monitor_grp = (u8)offer->monitorid / 32;
newchannel->monitor_bit = (u8)offer->monitorid % 32;
vmbus_process_offer(newchannel);
}
/*
* vmbus_onoffer_rescind - Rescind offer handler.
*
* We queue a work item to process this offer synchronously
*/
static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
{
struct vmbus_channel_rescind_offer *rescind;
struct vmbus_channel *channel;
unsigned long flags;
struct device *dev;
rescind = (struct vmbus_channel_rescind_offer *)hdr;
/*
* The offer msg and the corresponding rescind msg
* from the host are guranteed to be ordered -
* offer comes in first and then the rescind.
* Since we process these events in work elements,
* and with preemption, we may end up processing
* the events out of order. Given that we handle these
* work elements on the same CPU, this is possible only
* in the case of preemption. In any case wait here
* until the offer processing has moved beyond the
* point where the channel is discoverable.
*/
while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
/*
* We wait here until any channel offer is currently
* being processed.
*/
msleep(1);
}
mutex_lock(&vmbus_connection.channel_mutex);
channel = relid2channel(rescind->child_relid);
mutex_unlock(&vmbus_connection.channel_mutex);
if (channel == NULL) {
/*
* We failed in processing the offer message;
* we would have cleaned up the relid in that
* failure path.
*/
return;
}
spin_lock_irqsave(&channel->lock, flags);
channel->rescind = true;
spin_unlock_irqrestore(&channel->lock, flags);
/*
* Now that we have posted the rescind state, perform
* rescind related cleanup.
*/
vmbus_rescind_cleanup(channel);
/*
* Now wait for offer handling to complete.
*/
while (READ_ONCE(channel->probe_done) == false) {
/*
* We wait here until any channel offer is currently
* being processed.
*/
msleep(1);
}
/*
* At this point, the rescind handling can proceed safely.
*/
if (channel->device_obj) {
if (channel->chn_rescind_callback) {
channel->chn_rescind_callback(channel);
return;
}
/*
* We will have to unregister this device from the
* driver core.
*/
dev = get_device(&channel->device_obj->device);
if (dev) {
vmbus_device_unregister(channel->device_obj);
put_device(dev);
}
}
if (channel->primary_channel != NULL) {
/*
* Sub-channel is being rescinded. Following is the channel
* close sequence when initiated from the driveri (refer to
* vmbus_close() for details):
* 1. Close all sub-channels first
* 2. Then close the primary channel.
*/
if (channel->state == CHANNEL_OPEN_STATE) {
/*
* The channel is currently not open;
* it is safe for us to cleanup the channel.
*/
mutex_lock(&vmbus_connection.channel_mutex);
hv_process_channel_removal(channel,
channel->offermsg.child_relid);
mutex_unlock(&vmbus_connection.channel_mutex);
}
}
}
void vmbus_hvsock_device_unregister(struct vmbus_channel *channel)
{
BUG_ON(!is_hvsock_channel(channel));
channel->rescind = true;
vmbus_device_unregister(channel->device_obj);
}
EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister);
/*
* vmbus_onoffers_delivered -
* This is invoked when all offers have been delivered.
*
* Nothing to do here.
*/
static void vmbus_onoffers_delivered(
struct vmbus_channel_message_header *hdr)
{
}
/*
* vmbus_onopen_result - Open result handler.
*
* This is invoked when we received a response to our channel open request.
* Find the matching request, copy the response and signal the requesting
* thread.
*/
static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr)
{
struct vmbus_channel_open_result *result;
struct vmbus_channel_msginfo *msginfo;
struct vmbus_channel_message_header *requestheader;
struct vmbus_channel_open_channel *openmsg;
unsigned long flags;
result = (struct vmbus_channel_open_result *)hdr;
/*
* Find the open msg, copy the result and signal/unblock the wait event
*/
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
msglistentry) {
requestheader =
(struct vmbus_channel_message_header *)msginfo->msg;
if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) {
openmsg =
(struct vmbus_channel_open_channel *)msginfo->msg;
if (openmsg->child_relid == result->child_relid &&
openmsg->openid == result->openid) {
memcpy(&msginfo->response.open_result,
result,
sizeof(
struct vmbus_channel_open_result));
complete(&msginfo->waitevent);
break;
}
}
}
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}
/*
* vmbus_ongpadl_created - GPADL created handler.
*
* This is invoked when we received a response to our gpadl create request.
* Find the matching request, copy the response and signal the requesting
* thread.
*/
static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr)
{
struct vmbus_channel_gpadl_created *gpadlcreated;
struct vmbus_channel_msginfo *msginfo;
struct vmbus_channel_message_header *requestheader;
struct vmbus_channel_gpadl_header *gpadlheader;
unsigned long flags;
gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr;
/*
* Find the establish msg, copy the result and signal/unblock the wait
* event
*/
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
msglistentry) {
requestheader =
(struct vmbus_channel_message_header *)msginfo->msg;
if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) {
gpadlheader =
(struct vmbus_channel_gpadl_header *)requestheader;
if ((gpadlcreated->child_relid ==
gpadlheader->child_relid) &&
(gpadlcreated->gpadl == gpadlheader->gpadl)) {
memcpy(&msginfo->response.gpadl_created,
gpadlcreated,
sizeof(
struct vmbus_channel_gpadl_created));
complete(&msginfo->waitevent);
break;
}
}
}
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}
/*
* vmbus_ongpadl_torndown - GPADL torndown handler.
*
* This is invoked when we received a response to our gpadl teardown request.
* Find the matching request, copy the response and signal the requesting
* thread.
*/
static void vmbus_ongpadl_torndown(
struct vmbus_channel_message_header *hdr)
{
struct vmbus_channel_gpadl_torndown *gpadl_torndown;
struct vmbus_channel_msginfo *msginfo;
struct vmbus_channel_message_header *requestheader;
struct vmbus_channel_gpadl_teardown *gpadl_teardown;
unsigned long flags;
gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr;
/*
* Find the open msg, copy the result and signal/unblock the wait event
*/
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
msglistentry) {
requestheader =
(struct vmbus_channel_message_header *)msginfo->msg;
if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) {
gpadl_teardown =
(struct vmbus_channel_gpadl_teardown *)requestheader;
if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) {
memcpy(&msginfo->response.gpadl_torndown,
gpadl_torndown,
sizeof(
struct vmbus_channel_gpadl_torndown));
complete(&msginfo->waitevent);
break;
}
}
}
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}
/*
* vmbus_onversion_response - Version response handler
*
* This is invoked when we received a response to our initiate contact request.
* Find the matching request, copy the response and signal the requesting
* thread.
*/
static void vmbus_onversion_response(
struct vmbus_channel_message_header *hdr)
{
struct vmbus_channel_msginfo *msginfo;
struct vmbus_channel_message_header *requestheader;
struct vmbus_channel_version_response *version_response;
unsigned long flags;
version_response = (struct vmbus_channel_version_response *)hdr;
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
msglistentry) {
requestheader =
(struct vmbus_channel_message_header *)msginfo->msg;
if (requestheader->msgtype ==
CHANNELMSG_INITIATE_CONTACT) {
memcpy(&msginfo->response.version_response,
version_response,
sizeof(struct vmbus_channel_version_response));
complete(&msginfo->waitevent);
}
}
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}
/* Channel message dispatch table */
const struct vmbus_channel_message_table_entry
channel_message_table[CHANNELMSG_COUNT] = {
{ CHANNELMSG_INVALID, 0, NULL },
{ CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer },
{ CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind },
{ CHANNELMSG_REQUESTOFFERS, 0, NULL },
{ CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered },
{ CHANNELMSG_OPENCHANNEL, 0, NULL },
{ CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result },
{ CHANNELMSG_CLOSECHANNEL, 0, NULL },
{ CHANNELMSG_GPADL_HEADER, 0, NULL },
{ CHANNELMSG_GPADL_BODY, 0, NULL },
{ CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created },
{ CHANNELMSG_GPADL_TEARDOWN, 0, NULL },
{ CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown },
{ CHANNELMSG_RELID_RELEASED, 0, NULL },
{ CHANNELMSG_INITIATE_CONTACT, 0, NULL },
{ CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response },
{ CHANNELMSG_UNLOAD, 0, NULL },
{ CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response },
{ CHANNELMSG_18, 0, NULL },
{ CHANNELMSG_19, 0, NULL },
{ CHANNELMSG_20, 0, NULL },
{ CHANNELMSG_TL_CONNECT_REQUEST, 0, NULL },
};
/*
* vmbus_onmessage - Handler for channel protocol messages.
*
* This is invoked in the vmbus worker thread context.
*/
void vmbus_onmessage(void *context)
{
struct hv_message *msg = context;
struct vmbus_channel_message_header *hdr;
int size;
hdr = (struct vmbus_channel_message_header *)msg->u.payload;
size = msg->header.payload_size;
if (hdr->msgtype >= CHANNELMSG_COUNT) {
pr_err("Received invalid channel message type %d size %d\n",
hdr->msgtype, size);
print_hex_dump_bytes("", DUMP_PREFIX_NONE,
(unsigned char *)msg->u.payload, size);
return;
}
if (channel_message_table[hdr->msgtype].message_handler)
channel_message_table[hdr->msgtype].message_handler(hdr);
else
pr_err("Unhandled channel message type %d\n", hdr->msgtype);
}
/*
* vmbus_request_offers - Send a request to get all our pending offers.
*/
int vmbus_request_offers(void)
{
struct vmbus_channel_message_header *msg;
struct vmbus_channel_msginfo *msginfo;
int ret;
msginfo = kmalloc(sizeof(*msginfo) +
sizeof(struct vmbus_channel_message_header),
GFP_KERNEL);
if (!msginfo)
return -ENOMEM;
msg = (struct vmbus_channel_message_header *)msginfo->msg;
msg->msgtype = CHANNELMSG_REQUESTOFFERS;
ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_message_header),
true);
if (ret != 0) {
pr_err("Unable to request offers - %d\n", ret);
goto cleanup;
}
cleanup:
kfree(msginfo);
return ret;
}
/*
* Retrieve the (sub) channel on which to send an outgoing request.
* When a primary channel has multiple sub-channels, we try to
* distribute the load equally amongst all available channels.
*/
struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
{
struct list_head *cur, *tmp;
int cur_cpu;
struct vmbus_channel *cur_channel;
struct vmbus_channel *outgoing_channel = primary;
int next_channel;
int i = 1;
if (list_empty(&primary->sc_list))
return outgoing_channel;
next_channel = primary->next_oc++;
if (next_channel > (primary->num_sc)) {
primary->next_oc = 0;
return outgoing_channel;
}
cur_cpu = hv_cpu_number_to_vp_number(smp_processor_id());
list_for_each_safe(cur, tmp, &primary->sc_list) {
cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
if (cur_channel->state != CHANNEL_OPENED_STATE)
continue;
if (cur_channel->target_vp == cur_cpu)
return cur_channel;
if (i == next_channel)
return cur_channel;
i++;
}
return outgoing_channel;
}
EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel);
static void invoke_sc_cb(struct vmbus_channel *primary_channel)
{
struct list_head *cur, *tmp;
struct vmbus_channel *cur_channel;
if (primary_channel->sc_creation_callback == NULL)
return;
list_for_each_safe(cur, tmp, &primary_channel->sc_list) {
cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
primary_channel->sc_creation_callback(cur_channel);
}
}
void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
void (*sc_cr_cb)(struct vmbus_channel *new_sc))
{
primary_channel->sc_creation_callback = sc_cr_cb;
}
EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback);
bool vmbus_are_subchannels_present(struct vmbus_channel *primary)
{
bool ret;
ret = !list_empty(&primary->sc_list);
if (ret) {
/*
* Invoke the callback on sub-channel creation.
* This will present a uniform interface to the
* clients.
*/
invoke_sc_cb(primary);
}
return ret;
}
EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present);
void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel,
void (*chn_rescind_cb)(struct vmbus_channel *))
{
channel->chn_rescind_callback = chn_rescind_cb;
}
EXPORT_SYMBOL_GPL(vmbus_set_chn_rescind_callback);
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