blob: 253a74ba245cb0011706f1644fca674f67a52441 [file] [log] [blame]
Hank Janssen3e7ee492009-07-13 16:02:34 -07001/*
2 *
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307 USA.
17 *
18 * Authors:
19 * Haiyang Zhang <haiyangz@microsoft.com>
20 * Hank Janssen <hjanssen@microsoft.com>
21 *
22 */
Hank Janssen0a466182011-03-29 13:58:47 -070023#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
Greg Kroah-Hartmana0086dc2009-08-17 17:22:08 -070025#include <linux/kernel.h>
K. Y. Srinivasan0c3b7b22011-02-11 09:59:43 -080026#include <linux/sched.h>
27#include <linux/wait.h>
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -070028#include <linux/delay.h>
Greg Kroah-Hartmana0086dc2009-08-17 17:22:08 -070029#include <linux/mm.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090030#include <linux/slab.h>
Greg Kroah-Hartmana0086dc2009-08-17 17:22:08 -070031#include <linux/vmalloc.h>
Greg Kroah-Hartman46a97192011-10-04 12:29:52 -070032#include <linux/hyperv.h>
K. Y. Srinivasan37f72782012-12-01 06:46:41 -080033#include <linux/export.h>
Greg Kroah-Hartman407dd162011-10-11 08:36:44 -060034#include <asm/hyperv.h>
K. Y. Srinivasan0f2a6612011-05-12 19:34:28 -070035#include "hyperv_vmbus.h"
Hank Janssen3e7ee492009-07-13 16:02:34 -070036
Hank Janssen3e7ee492009-07-13 16:02:34 -070037
Haiyang Zhangda9fcb72011-01-26 12:12:14 -080038struct vmbus_connection vmbus_connection = {
39 .conn_state = DISCONNECTED,
40 .next_gpadl_handle = ATOMIC_INIT(0xE1E10),
Hank Janssen3e7ee492009-07-13 16:02:34 -070041};
42
Hank Janssen3e189512010-03-04 22:11:00 +000043/*
K. Y. Srinivasan37f72782012-12-01 06:46:41 -080044 * Negotiated protocol version with the host.
45 */
46__u32 vmbus_proto_version;
47EXPORT_SYMBOL_GPL(vmbus_proto_version);
48
K. Y. Srinivasan610071c2012-12-01 06:46:38 -080049static __u32 vmbus_get_next_version(__u32 current_version)
50{
51 switch (current_version) {
52 case (VERSION_WIN7):
53 return VERSION_WS2008;
54
55 case (VERSION_WIN8):
56 return VERSION_WIN7;
57
58 case (VERSION_WS2008):
59 default:
60 return VERSION_INVAL;
61 }
62}
63
64static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
65 __u32 version)
66{
67 int ret = 0;
68 struct vmbus_channel_initiate_contact *msg;
69 unsigned long flags;
70 int t;
71
72 init_completion(&msginfo->waitevent);
73
74 msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;
75
76 msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
77 msg->vmbus_version_requested = version;
78 msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
79 msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages);
80 msg->monitor_page2 = virt_to_phys(
81 (void *)((unsigned long)vmbus_connection.monitor_pages +
82 PAGE_SIZE));
83
84 /*
85 * Add to list before we send the request since we may
86 * receive the response before returning from this routine
87 */
88 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
89 list_add_tail(&msginfo->msglistentry,
90 &vmbus_connection.chn_msg_list);
91
92 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
93
94 ret = vmbus_post_msg(msg,
95 sizeof(struct vmbus_channel_initiate_contact));
96 if (ret != 0) {
97 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
98 list_del(&msginfo->msglistentry);
99 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
100 flags);
101 return ret;
102 }
103
104 /* Wait for the connection response */
105 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
106 if (t == 0) {
107 spin_lock_irqsave(&vmbus_connection.channelmsg_lock,
108 flags);
109 list_del(&msginfo->msglistentry);
110 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
111 flags);
112 return -ETIMEDOUT;
113 }
114
115 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
116 list_del(&msginfo->msglistentry);
117 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
118
119 /* Check if successful */
120 if (msginfo->response.version_response.version_supported) {
121 vmbus_connection.conn_state = CONNECTED;
122 } else {
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800123 return -ECONNREFUSED;
124 }
125
126 return ret;
127}
128
129/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800130 * vmbus_connect - Sends a connect request on the partition service connection
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700131 */
Haiyang Zhangc6977672011-01-26 12:12:08 -0800132int vmbus_connect(void)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700133{
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700134 int ret = 0;
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800135 struct vmbus_channel_msginfo *msginfo = NULL;
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800136 __u32 version;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700137
Bill Pemberton454f18a2009-07-27 16:47:24 -0400138 /* Initialize the vmbus connection */
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800139 vmbus_connection.conn_state = CONNECTING;
140 vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
141 if (!vmbus_connection.work_queue) {
K. Y. Srinivasan3a7546d2011-06-06 15:50:10 -0700142 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700143 goto cleanup;
Bill Pembertonde65a382009-07-29 17:00:09 -0400144 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700145
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800146 INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800147 spin_lock_init(&vmbus_connection.channelmsg_lock);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700148
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800149 INIT_LIST_HEAD(&vmbus_connection.chn_list);
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800150 spin_lock_init(&vmbus_connection.channel_lock);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700151
Bill Pemberton454f18a2009-07-27 16:47:24 -0400152 /*
153 * Setup the vmbus event connection for channel interrupt
154 * abstraction stuff
155 */
K. Y. Srinivasandf3493e2011-02-11 09:59:00 -0800156 vmbus_connection.int_page =
157 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800158 if (vmbus_connection.int_page == NULL) {
K. Y. Srinivasan3a7546d2011-06-06 15:50:10 -0700159 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700160 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700161 }
162
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800163 vmbus_connection.recv_int_page = vmbus_connection.int_page;
164 vmbus_connection.send_int_page =
165 (void *)((unsigned long)vmbus_connection.int_page +
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700166 (PAGE_SIZE >> 1));
Hank Janssen3e7ee492009-07-13 16:02:34 -0700167
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700168 /*
169 * Setup the monitor notification facility. The 1st page for
170 * parent->child and the 2nd page for child->parent
Bill Pemberton454f18a2009-07-27 16:47:24 -0400171 */
K. Y. Srinivasandf3493e2011-02-11 09:59:00 -0800172 vmbus_connection.monitor_pages =
173 (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 1);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800174 if (vmbus_connection.monitor_pages == NULL) {
K. Y. Srinivasan3a7546d2011-06-06 15:50:10 -0700175 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700176 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700177 }
178
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800179 msginfo = kzalloc(sizeof(*msginfo) +
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700180 sizeof(struct vmbus_channel_initiate_contact),
181 GFP_KERNEL);
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800182 if (msginfo == NULL) {
Bill Pemberton8cad0af2010-05-05 15:27:32 -0400183 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700184 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700185 }
186
Bill Pemberton454f18a2009-07-27 16:47:24 -0400187 /*
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800188 * Negotiate a compatible VMBUS version number with the
189 * host. We start with the highest number we can support
190 * and work our way down until we negotiate a compatible
191 * version.
Bill Pemberton454f18a2009-07-27 16:47:24 -0400192 */
Bill Pemberton53af5452009-09-11 21:46:44 -0400193
K. Y. Srinivasan2a5c43a2012-12-01 06:46:56 -0800194 version = VERSION_CURRENT;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700195
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800196 do {
197 ret = vmbus_negotiate_version(msginfo, version);
198 if (ret == 0)
199 break;
200
201 version = vmbus_get_next_version(version);
202 } while (version != VERSION_INVAL);
203
204 if (version == VERSION_INVAL)
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700205 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700206
K. Y. Srinivasan37f72782012-12-01 06:46:41 -0800207 vmbus_proto_version = version;
K. Y. Srinivasan3bacaf0c2012-12-01 06:46:59 -0800208 pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n",
209 host_info_eax, host_info_ebx >> 16,
210 host_info_ebx & 0xFFFF, host_info_ecx,
211 host_info_edx >> 24, host_info_edx & 0xFFFFFF,
212 version >> 16, version & 0xFFFF);
213
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800214 kfree(msginfo);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700215 return 0;
216
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700217cleanup:
K. Y. Srinivasan3bacaf0c2012-12-01 06:46:59 -0800218 pr_err("Unable to connect to host\n");
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800219 vmbus_connection.conn_state = DISCONNECTED;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700220
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800221 if (vmbus_connection.work_queue)
222 destroy_workqueue(vmbus_connection.work_queue);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700223
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800224 if (vmbus_connection.int_page) {
K. Y. Srinivasandf3493e2011-02-11 09:59:00 -0800225 free_pages((unsigned long)vmbus_connection.int_page, 0);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800226 vmbus_connection.int_page = NULL;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700227 }
228
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800229 if (vmbus_connection.monitor_pages) {
K. Y. Srinivasandf3493e2011-02-11 09:59:00 -0800230 free_pages((unsigned long)vmbus_connection.monitor_pages, 1);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800231 vmbus_connection.monitor_pages = NULL;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700232 }
233
Ilia Mirkindd9b15d2011-03-13 00:29:00 -0500234 kfree(msginfo);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700235
Hank Janssen3e7ee492009-07-13 16:02:34 -0700236 return ret;
237}
238
Hank Janssen3e7ee492009-07-13 16:02:34 -0700239
Hank Janssen3e189512010-03-04 22:11:00 +0000240/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800241 * relid2channel - Get the channel object given its
242 * child relative id (ie channel id)
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700243 */
Haiyang Zhangc6977672011-01-26 12:12:08 -0800244struct vmbus_channel *relid2channel(u32 relid)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700245{
Greg Kroah-Hartmanaded71652009-08-18 15:21:19 -0700246 struct vmbus_channel *channel;
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800247 struct vmbus_channel *found_channel = NULL;
Greg Kroah-Hartman0f5e44c2009-07-15 14:57:16 -0700248 unsigned long flags;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700249
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800250 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800251 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800252 if (channel->offermsg.child_relid == relid) {
253 found_channel = channel;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700254 break;
255 }
256 }
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800257 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700258
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800259 return found_channel;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700260}
261
Hank Janssen3e189512010-03-04 22:11:00 +0000262/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800263 * process_chn_event - Process a channel event notification
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700264 */
Olaf Hering35436482011-04-16 18:50:40 +0200265static void process_chn_event(u32 relid)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700266{
Greg Kroah-Hartmanaded71652009-08-18 15:21:19 -0700267 struct vmbus_channel *channel;
K. Y. Srinivasandad76bf2011-08-27 11:31:33 -0700268 unsigned long flags;
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800269 void *arg;
270 bool read_state;
271 u32 bytes_to_read;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700272
Bill Pemberton454f18a2009-07-27 16:47:24 -0400273 /*
274 * Find the channel based on this relid and invokes the
275 * channel callback to process the event
276 */
Haiyang Zhangc6977672011-01-26 12:12:08 -0800277 channel = relid2channel(relid);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700278
K. Y. Srinivasan24326032011-08-31 14:35:57 -0700279 if (!channel) {
280 pr_err("channel not found for relid - %u\n", relid);
281 return;
282 }
283
284 /*
285 * A channel once created is persistent even when there
286 * is no driver handling the device. An unloading driver
287 * sets the onchannel_callback to NULL under the
288 * protection of the channel inbound_lock. Thus, checking
289 * and invoking the driver specific callback takes care of
290 * orderly unloading of the driver.
291 */
292
K. Y. Srinivasandad76bf2011-08-27 11:31:33 -0700293 spin_lock_irqsave(&channel->inbound_lock, flags);
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800294 if (channel->onchannel_callback != NULL) {
295 arg = channel->channel_callback_context;
296 read_state = channel->batched_reading;
297 /*
298 * This callback reads the messages sent by the host.
299 * We can optimize host to guest signaling by ensuring:
300 * 1. While reading the channel, we disable interrupts from
301 * host.
302 * 2. Ensure that we process all posted messages from the host
303 * before returning from this callback.
304 * 3. Once we return, enable signaling from the host. Once this
305 * state is set we check to see if additional packets are
306 * available to read. In this case we repeat the process.
307 */
308
309 do {
310 hv_begin_read(&channel->inbound);
311 channel->onchannel_callback(arg);
312 bytes_to_read = hv_end_read(&channel->inbound);
313 } while (read_state && (bytes_to_read != 0));
314 } else {
K. Y. Srinivasan24326032011-08-31 14:35:57 -0700315 pr_err("no channel callback for relid - %u\n", relid);
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800316 }
K. Y. Srinivasand9add43b2011-08-27 11:31:43 -0700317
K. Y. Srinivasandad76bf2011-08-27 11:31:33 -0700318 spin_unlock_irqrestore(&channel->inbound_lock, flags);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700319}
320
Hank Janssen3e189512010-03-04 22:11:00 +0000321/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800322 * vmbus_on_event - Handler for events
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700323 */
K. Y. Srinivasan6de3d6a2011-03-10 14:05:16 -0800324void vmbus_on_event(unsigned long data)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700325{
Olaf Hering35436482011-04-16 18:50:40 +0200326 u32 dword;
K. Y. Srinivasan6552ecd2012-12-01 06:46:49 -0800327 u32 maxdword;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700328 int bit;
Olaf Hering35436482011-04-16 18:50:40 +0200329 u32 relid;
K. Y. Srinivasan6552ecd2012-12-01 06:46:49 -0800330 u32 *recv_int_page = NULL;
331 void *page_addr;
332 int cpu = smp_processor_id();
333 union hv_synic_event_flags *event;
334
335 if ((vmbus_proto_version == VERSION_WS2008) ||
336 (vmbus_proto_version == VERSION_WIN7)) {
337 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
338 recv_int_page = vmbus_connection.recv_int_page;
339 } else {
340 /*
341 * When the host is win8 and beyond, the event page
342 * can be directly checked to get the id of the channel
343 * that has the interrupt pending.
344 */
345 maxdword = HV_EVENT_FLAGS_DWORD_COUNT;
346 page_addr = hv_context.synic_event_page[cpu];
347 event = (union hv_synic_event_flags *)page_addr +
348 VMBUS_MESSAGE_SINT;
349 recv_int_page = event->flags32;
350 }
351
352
Hank Janssen3e7ee492009-07-13 16:02:34 -0700353
Bill Pemberton454f18a2009-07-27 16:47:24 -0400354 /* Check events */
Olaf Hering242b45a2011-04-16 18:50:39 +0200355 if (!recv_int_page)
356 return;
357 for (dword = 0; dword < maxdword; dword++) {
358 if (!recv_int_page[dword])
359 continue;
360 for (bit = 0; bit < 32; bit++) {
K. Y. Srinivasand9add43b2011-08-27 11:31:43 -0700361 if (sync_test_and_clear_bit(bit,
362 (unsigned long *)&recv_int_page[dword])) {
Olaf Hering242b45a2011-04-16 18:50:39 +0200363 relid = (dword << 5) + bit;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700364
K. Y. Srinivasand9add43b2011-08-27 11:31:43 -0700365 if (relid == 0)
K. Y. Srinivasan6d81d332011-05-10 07:55:45 -0700366 /*
367 * Special case - vmbus
368 * channel protocol msg
369 */
Olaf Hering242b45a2011-04-16 18:50:39 +0200370 continue;
K. Y. Srinivasand9add43b2011-08-27 11:31:43 -0700371
Olaf Hering35436482011-04-16 18:50:40 +0200372 process_chn_event(relid);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700373 }
Olaf Hering242b45a2011-04-16 18:50:39 +0200374 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700375 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700376}
377
Hank Janssen3e189512010-03-04 22:11:00 +0000378/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800379 * vmbus_post_msg - Send a msg on the vmbus's message connection
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700380 */
Haiyang Zhangc6977672011-01-26 12:12:08 -0800381int vmbus_post_msg(void *buffer, size_t buflen)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700382{
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800383 union hv_connection_id conn_id;
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -0700384 int ret = 0;
385 int retries = 0;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700386
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800387 conn_id.asu32 = 0;
388 conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -0700389
390 /*
391 * hv_post_message() can have transient failures because of
392 * insufficient resources. Retry the operation a couple of
393 * times before giving up.
394 */
395 while (retries < 3) {
396 ret = hv_post_message(conn_id, 1, buffer, buflen);
397 if (ret != HV_STATUS_INSUFFICIENT_BUFFERS)
398 return ret;
399 retries++;
400 msleep(100);
401 }
402 return ret;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700403}
404
Hank Janssen3e189512010-03-04 22:11:00 +0000405/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800406 * vmbus_set_event - Send an event notification to the parent
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700407 */
K. Y. Srinivasan21c3bef2012-12-01 06:46:43 -0800408int vmbus_set_event(struct vmbus_channel *channel)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700409{
K. Y. Srinivasan21c3bef2012-12-01 06:46:43 -0800410 u32 child_relid = channel->offermsg.child_relid;
Bill Pemberton7c369f42009-07-29 17:00:11 -0400411
K. Y. Srinivasan3be77772012-12-01 06:46:46 -0800412 if (!channel->is_dedicated_interrupt) {
413 /* Each u32 represents 32 channels */
414 sync_set_bit(child_relid & 31,
415 (unsigned long *)vmbus_connection.send_int_page +
416 (child_relid >> 5));
417 }
418
419 return hv_signal_event(channel->sig_event);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700420}