linux/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/sched.h>
#include <linux/wait.h>
#include <linux/mm.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/hyperv.h>
#include "hyperv_vmbus.h"
struct vmbus_channel_message_table_entry {
enum vmbus_channel_message_type message_type;
void (*message_handler)(struct vmbus_channel_message_header *msg);
};
/**
* 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.
* @negop is of type &struct icmsg_negotiate.
* Set up and fill in default negotiate response message.
*
* The max_fw_version specifies the maximum framework version that
* we can support and max _srv_version specifies the maximum service
* version we can support. A special value MAX_SRV_VER can be
* specified to indicate that we can handle the maximum version
* exposed by the host.
*
* Mainly used by Hyper-V drivers.
*/
void vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
struct icmsg_negotiate *negop, u8 *buf,
int max_fw_version, int max_srv_version)
{
int icframe_vercnt;
int icmsg_vercnt;
int i;
icmsghdrp->icmsgsize = 0x10;
negop = (struct icmsg_negotiate *)&buf[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
icframe_vercnt = negop->icframe_vercnt;
icmsg_vercnt = negop->icmsg_vercnt;
/*
* Select the framework version number we will
* support.
*/
for (i = 0; i < negop->icframe_vercnt; i++) {
if (negop->icversion_data[i].major <= max_fw_version)
icframe_vercnt = negop->icversion_data[i].major;
}
for (i = negop->icframe_vercnt;
(i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
if (negop->icversion_data[i].major <= max_srv_version)
icmsg_vercnt = negop->icversion_data[i].major;
}
/*
* Respond with the maximum framework and service
* version numbers we can support.
*/
negop->icframe_vercnt = 1;
negop->icmsg_vercnt = 1;
negop->icversion_data[0].major = icframe_vercnt;
negop->icversion_data[0].minor = 0;
negop->icversion_data[1].major = icmsg_vercnt;
negop->icversion_data[1].minor = 0;
}
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->inbound_lock);
spin_lock_init(&channel->sc_lock);
INIT_LIST_HEAD(&channel->sc_list);
channel->controlwq = create_workqueue("hv_vmbus_ctl");
if (!channel->controlwq) {
kfree(channel);
return NULL;
}
return channel;
}
/*
* release_hannel - Release the vmbus channel object itself
*/
static void release_channel(struct work_struct *work)
{
struct vmbus_channel *channel = container_of(work,
struct vmbus_channel,
work);
destroy_workqueue(channel->controlwq);
kfree(channel);
}
/*
* free_channel - Release the resources used by the vmbus channel object
*/
static void free_channel(struct vmbus_channel *channel)
{
/*
* We have to release the channel's workqueue/thread in the vmbus's
* workqueue/thread context
* ie we can't destroy ourselves.
*/
INIT_WORK(&channel->work, release_channel);
queue_work(vmbus_connection.work_queue, &channel->work);
}
/*
* vmbus_process_rescind_offer -
* Rescind the offer by initiating a device removal
*/
static void vmbus_process_rescind_offer(struct work_struct *work)
{
struct vmbus_channel *channel = container_of(work,
struct vmbus_channel,
work);
unsigned long flags;
struct vmbus_channel *primary_channel;
struct vmbus_channel_relid_released msg;
vmbus_device_unregister(channel->device_obj);
memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
msg.child_relid = channel->offermsg.child_relid;
msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
if (channel->primary_channel == NULL) {
spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
list_del(&channel->listentry);
spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
} else {
primary_channel = channel->primary_channel;
spin_lock_irqsave(&primary_channel->sc_lock, flags);
list_del(&channel->listentry);
spin_unlock_irqrestore(&primary_channel->sc_lock, flags);
}
free_channel(channel);
}
void vmbus_free_channels(void)
{
struct vmbus_channel *channel;
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
vmbus_device_unregister(channel->device_obj);
kfree(channel->device_obj);
free_channel(channel);
}
}
/*
* vmbus_process_offer - Process the offer by creating a channel/device
* associated with this offer
*/
static void vmbus_process_offer(struct work_struct *work)
{
struct vmbus_channel *newchannel = container_of(work,
struct vmbus_channel,
work);
struct vmbus_channel *channel;
bool fnew = true;
int ret;
unsigned long flags;
/* The next possible work is rescind handling */
INIT_WORK(&newchannel->work, vmbus_process_rescind_offer);
/* Make sure this is a new offer */
spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
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);
spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
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->sc_lock, flags);
list_add_tail(&newchannel->sc_list, &channel->sc_list);
spin_unlock_irqrestore(&channel->sc_lock, flags);
newchannel->state = CHANNEL_OPEN_STATE;
if (channel->sc_creation_callback != NULL)
channel->sc_creation_callback(newchannel);
return;
}
free_channel(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);
/*
* 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);
spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
list_del(&newchannel->listentry);
spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
kfree(newchannel->device_obj);
free_channel(newchannel);
} else {
/*
* 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;
}
}
enum {
IDE = 0,
SCSI,
NIC,
MAX_PERF_CHN,
};
/*
* This is an array of device_ids (device types) that are performance critical.
* We attempt to distribute the interrupt load for these devices across
* all available CPUs.
*/
static const struct hv_vmbus_device_id hp_devs[] = {
/* IDE */
{ HV_IDE_GUID, },
/* Storage - SCSI */
{ HV_SCSI_GUID, },
/* Network */
{ HV_NIC_GUID, },
};
/*
* We use this state to statically distribute the channel interrupt load.
*/
static u32 next_vp;
/*
* Starting with Win8, we can statically distribute the incoming
* channel interrupt load by binding a channel to VCPU. We
* implement here a simple round robin scheme for distributing
* the interrupt load.
* We will bind channels that are not performance critical to cpu 0 and
* performance critical channels (IDE, SCSI and Network) will be uniformly
* distributed across all available CPUs.
*/
static u32 get_vp_index(uuid_le *type_guid)
{
u32 cur_cpu;
int i;
bool perf_chn = false;
u32 max_cpus = num_online_cpus();
for (i = IDE; i < MAX_PERF_CHN; i++) {
if (!memcmp(type_guid->b, hp_devs[i].guid,
sizeof(uuid_le))) {
perf_chn = true;
break;
}
}
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.
*/
return 0;
}
cur_cpu = (++next_vp % max_cpus);
return hv_context.vp_index[cur_cpu];
}
/*
* 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) {
pr_err("Unable to allocate channel object\n");
return;
}
/*
* By default we setup state to enable batched
* reading. A specific service can choose to
* disable this prior to opening the channel.
*/
newchannel->batched_reading = true;
/*
* Setup state for signalling the host.
*/
newchannel->sig_event = (struct hv_input_signal_event *)
(ALIGN((unsigned long)
&newchannel->sig_buf,
HV_HYPERCALL_PARAM_ALIGN));
newchannel->sig_event->connectionid.asu32 = 0;
newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
newchannel->sig_event->flag_number = 0;
newchannel->sig_event->rsvdz = 0;
if (vmbus_proto_version != VERSION_WS2008) {
newchannel->is_dedicated_interrupt =
(offer->is_dedicated_interrupt != 0);
newchannel->sig_event->connectionid.u.id =
offer->connection_id;
}
newchannel->target_vp = get_vp_index(&offer->offer.if_type);
memcpy(&newchannel->offermsg, offer,
sizeof(struct vmbus_channel_offer_channel));
newchannel->monitor_grp = (u8)offer->monitorid / 32;
newchannel->monitor_bit = (u8)offer->monitorid % 32;
INIT_WORK(&newchannel->work, vmbus_process_offer);
queue_work(newchannel->controlwq, &newchannel->work);
}
/*
* 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;
rescind = (struct vmbus_channel_rescind_offer *)hdr;
channel = relid2channel(rescind->child_relid);
if (channel == NULL)
/* Just return here, no channel found */
return;
/* work is initialized for vmbus_process_rescind_offer() from
* vmbus_process_offer() where the channel got created */
queue_work(channel->controlwq, &channel->work);
}
/*
* 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 */
static struct vmbus_channel_message_table_entry
channel_message_table[CHANNELMSG_COUNT] = {
{CHANNELMSG_INVALID, NULL},
{CHANNELMSG_OFFERCHANNEL, vmbus_onoffer},
{CHANNELMSG_RESCIND_CHANNELOFFER, vmbus_onoffer_rescind},
{CHANNELMSG_REQUESTOFFERS, NULL},
{CHANNELMSG_ALLOFFERS_DELIVERED, vmbus_onoffers_delivered},
{CHANNELMSG_OPENCHANNEL, NULL},
{CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result},
{CHANNELMSG_CLOSECHANNEL, NULL},
{CHANNELMSG_GPADL_HEADER, NULL},
{CHANNELMSG_GPADL_BODY, NULL},
{CHANNELMSG_GPADL_CREATED, vmbus_ongpadl_created},
{CHANNELMSG_GPADL_TEARDOWN, NULL},
{CHANNELMSG_GPADL_TORNDOWN, vmbus_ongpadl_torndown},
{CHANNELMSG_RELID_RELEASED, NULL},
{CHANNELMSG_INITIATE_CONTACT, NULL},
{CHANNELMSG_VERSION_RESPONSE, vmbus_onversion_response},
{CHANNELMSG_UNLOAD, 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, t;
msginfo = kmalloc(sizeof(*msginfo) +
sizeof(struct vmbus_channel_message_header),
GFP_KERNEL);
if (!msginfo)
return -ENOMEM;
init_completion(&msginfo->waitevent);
msg = (struct vmbus_channel_message_header *)msginfo->msg;
msg->msgtype = CHANNELMSG_REQUESTOFFERS;
ret = vmbus_post_msg(msg,
sizeof(struct vmbus_channel_message_header));
if (ret != 0) {
pr_err("Unable to request offers - %d\n", ret);
goto cleanup;
}
t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
if (t == 0) {
ret = -ETIMEDOUT;
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 choose a
* channel whose VCPU binding is closest to the VCPU on which
* this call is being made.
*/
struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
{
struct list_head *cur, *tmp;
int cur_cpu = hv_context.vp_index[smp_processor_id()];
struct vmbus_channel *cur_channel;
struct vmbus_channel *outgoing_channel = primary;
int cpu_distance, new_cpu_distance;
if (list_empty(&primary->sc_list))
return outgoing_channel;
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;
cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ?
(outgoing_channel->target_vp - cur_cpu) :
(cur_cpu - outgoing_channel->target_vp));
new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ?
(cur_channel->target_vp - cur_cpu) :
(cur_cpu - cur_channel->target_vp));
if (cpu_distance < new_cpu_distance)
continue;
outgoing_channel = cur_channel;
}
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);