blob: fcf8a02dc0eadb04522ce782be64a37dc8014813 [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
K. Y. Srinivasan03367ef2014-04-03 18:02:45 -070058 case (VERSION_WIN8_1):
59 return VERSION_WIN8;
60
Keith Mange6c4e5f92015-05-26 14:23:01 -070061 case (VERSION_WIN10):
62 return VERSION_WIN8_1;
63
K. Y. Srinivasan610071c2012-12-01 06:46:38 -080064 case (VERSION_WS2008):
65 default:
66 return VERSION_INVAL;
67 }
68}
69
70static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
71 __u32 version)
72{
73 int ret = 0;
74 struct vmbus_channel_initiate_contact *msg;
75 unsigned long flags;
K. Y. Srinivasan610071c2012-12-01 06:46:38 -080076
77 init_completion(&msginfo->waitevent);
78
79 msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;
80
81 msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
82 msg->vmbus_version_requested = version;
83 msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
Greg Kroah-Hartman8681db42013-09-13 11:32:55 -070084 msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
85 msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
K. Y. Srinivasanb282e4c2015-12-14 16:01:56 -080086 /*
87 * We want all channel messages to be delivered on CPU 0.
88 * This has been the behavior pre-win8. This is not
89 * perf issue and having all channel messages delivered on CPU 0
90 * would be ok.
Alex Ng72686442016-02-26 15:13:22 -080091 * For post win8 hosts, we support receiving channel messagges on
92 * all the CPUs. This is needed for kexec to work correctly where
93 * the CPU attempting to connect may not be CPU 0.
K. Y. Srinivasanb282e4c2015-12-14 16:01:56 -080094 */
Alex Ng72686442016-02-26 15:13:22 -080095 if (version >= VERSION_WIN8_1) {
96 msg->target_vcpu = hv_context.vp_index[get_cpu()];
97 put_cpu();
98 } else {
99 msg->target_vcpu = 0;
100 }
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800101
102 /*
103 * Add to list before we send the request since we may
104 * receive the response before returning from this routine
105 */
106 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
107 list_add_tail(&msginfo->msglistentry,
108 &vmbus_connection.chn_msg_list);
109
110 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
111
112 ret = vmbus_post_msg(msg,
113 sizeof(struct vmbus_channel_initiate_contact));
114 if (ret != 0) {
115 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
116 list_del(&msginfo->msglistentry);
117 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
118 flags);
119 return ret;
120 }
121
122 /* Wait for the connection response */
K. Y. Srinivasan269f9792014-01-16 11:59:58 -0800123 wait_for_completion(&msginfo->waitevent);
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800124
125 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
126 list_del(&msginfo->msglistentry);
127 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
128
129 /* Check if successful */
130 if (msginfo->response.version_response.version_supported) {
131 vmbus_connection.conn_state = CONNECTED;
132 } else {
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800133 return -ECONNREFUSED;
134 }
135
136 return ret;
137}
138
139/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800140 * vmbus_connect - Sends a connect request on the partition service connection
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700141 */
Haiyang Zhangc6977672011-01-26 12:12:08 -0800142int vmbus_connect(void)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700143{
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700144 int ret = 0;
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800145 struct vmbus_channel_msginfo *msginfo = NULL;
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800146 __u32 version;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700147
Bill Pemberton454f18a2009-07-27 16:47:24 -0400148 /* Initialize the vmbus connection */
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800149 vmbus_connection.conn_state = CONNECTING;
150 vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
151 if (!vmbus_connection.work_queue) {
K. Y. Srinivasan3a7546d2011-06-06 15:50:10 -0700152 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700153 goto cleanup;
Bill Pembertonde65a382009-07-29 17:00:09 -0400154 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700155
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800156 INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800157 spin_lock_init(&vmbus_connection.channelmsg_lock);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700158
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800159 INIT_LIST_HEAD(&vmbus_connection.chn_list);
Dexuan Cuid6f591e2015-12-14 16:01:51 -0800160 mutex_init(&vmbus_connection.channel_mutex);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700161
Bill Pemberton454f18a2009-07-27 16:47:24 -0400162 /*
163 * Setup the vmbus event connection for channel interrupt
164 * abstraction stuff
165 */
K. Y. Srinivasandf3493e2011-02-11 09:59:00 -0800166 vmbus_connection.int_page =
167 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800168 if (vmbus_connection.int_page == NULL) {
K. Y. Srinivasan3a7546d2011-06-06 15:50:10 -0700169 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700170 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700171 }
172
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800173 vmbus_connection.recv_int_page = vmbus_connection.int_page;
174 vmbus_connection.send_int_page =
175 (void *)((unsigned long)vmbus_connection.int_page +
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700176 (PAGE_SIZE >> 1));
Hank Janssen3e7ee492009-07-13 16:02:34 -0700177
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700178 /*
179 * Setup the monitor notification facility. The 1st page for
180 * parent->child and the 2nd page for child->parent
Bill Pemberton454f18a2009-07-27 16:47:24 -0400181 */
Greg Kroah-Hartman8681db42013-09-13 11:32:55 -0700182 vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
183 vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
184 if ((vmbus_connection.monitor_pages[0] == NULL) ||
185 (vmbus_connection.monitor_pages[1] == NULL)) {
K. Y. Srinivasan3a7546d2011-06-06 15:50:10 -0700186 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700187 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700188 }
189
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800190 msginfo = kzalloc(sizeof(*msginfo) +
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700191 sizeof(struct vmbus_channel_initiate_contact),
192 GFP_KERNEL);
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800193 if (msginfo == NULL) {
Bill Pemberton8cad0af2010-05-05 15:27:32 -0400194 ret = -ENOMEM;
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700195 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700196 }
197
Bill Pemberton454f18a2009-07-27 16:47:24 -0400198 /*
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800199 * Negotiate a compatible VMBUS version number with the
200 * host. We start with the highest number we can support
201 * and work our way down until we negotiate a compatible
202 * version.
Bill Pemberton454f18a2009-07-27 16:47:24 -0400203 */
Bill Pemberton53af5452009-09-11 21:46:44 -0400204
K. Y. Srinivasan2a5c43a2012-12-01 06:46:56 -0800205 version = VERSION_CURRENT;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700206
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800207 do {
208 ret = vmbus_negotiate_version(msginfo, version);
K. Y. Srinivasan8bbf9f42013-09-04 15:41:58 -0700209 if (ret == -ETIMEDOUT)
K. Y. Srinivasan666b9ad2013-08-28 14:56:54 -0700210 goto cleanup;
211
212 if (vmbus_connection.conn_state == CONNECTED)
K. Y. Srinivasan610071c2012-12-01 06:46:38 -0800213 break;
214
215 version = vmbus_get_next_version(version);
216 } while (version != VERSION_INVAL);
217
218 if (version == VERSION_INVAL)
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700219 goto cleanup;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700220
K. Y. Srinivasan37f72782012-12-01 06:46:41 -0800221 vmbus_proto_version = version;
K. Y. Srinivasan3bacaf0c2012-12-01 06:46:59 -0800222 pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n",
223 host_info_eax, host_info_ebx >> 16,
224 host_info_ebx & 0xFFFF, host_info_ecx,
225 host_info_edx >> 24, host_info_edx & 0xFFFFFF,
226 version >> 16, version & 0xFFFF);
227
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800228 kfree(msginfo);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700229 return 0;
230
K. Y. Srinivasanb0043862011-05-10 07:55:44 -0700231cleanup:
K. Y. Srinivasan3bacaf0c2012-12-01 06:46:59 -0800232 pr_err("Unable to connect to host\n");
Hank Janssen3e7ee492009-07-13 16:02:34 -0700233
Vitaly Kuznetsov09a19622015-02-27 11:25:54 -0800234 vmbus_connection.conn_state = DISCONNECTED;
235 vmbus_disconnect();
236
237 kfree(msginfo);
238
239 return ret;
240}
241
242void vmbus_disconnect(void)
243{
K. Y. Srinivasan2db84ef2015-04-22 21:31:32 -0700244 /*
245 * First send the unload request to the host.
246 */
Vitaly Kuznetsov75ff3a82016-02-26 15:13:16 -0800247 vmbus_initiate_unload(false);
K. Y. Srinivasan2db84ef2015-04-22 21:31:32 -0700248
Vitaly Kuznetsov09a19622015-02-27 11:25:54 -0800249 if (vmbus_connection.work_queue) {
250 drain_workqueue(vmbus_connection.work_queue);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800251 destroy_workqueue(vmbus_connection.work_queue);
Vitaly Kuznetsov09a19622015-02-27 11:25:54 -0800252 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700253
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800254 if (vmbus_connection.int_page) {
K. Y. Srinivasandf3493e2011-02-11 09:59:00 -0800255 free_pages((unsigned long)vmbus_connection.int_page, 0);
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800256 vmbus_connection.int_page = NULL;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700257 }
258
Radim Krčmářa100d88d2014-05-27 19:16:20 +0200259 free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0);
260 free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0);
Greg Kroah-Hartman8681db42013-09-13 11:32:55 -0700261 vmbus_connection.monitor_pages[0] = NULL;
262 vmbus_connection.monitor_pages[1] = NULL;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700263}
264
K. Y. Srinivasan3a28fa32014-04-08 18:45:54 -0700265/*
266 * Map the given relid to the corresponding channel based on the
267 * per-cpu list of channels that have been affinitized to this CPU.
268 * This will be used in the channel callback path as we can do this
269 * mapping in a lock-free fashion.
270 */
271static struct vmbus_channel *pcpu_relid2channel(u32 relid)
272{
273 struct vmbus_channel *channel;
274 struct vmbus_channel *found_channel = NULL;
275 int cpu = smp_processor_id();
276 struct list_head *pcpu_head = &hv_context.percpu_list[cpu];
277
278 list_for_each_entry(channel, pcpu_head, percpu_list) {
279 if (channel->offermsg.child_relid == relid) {
280 found_channel = channel;
281 break;
282 }
283 }
284
285 return found_channel;
286}
Hank Janssen3e7ee492009-07-13 16:02:34 -0700287
Hank Janssen3e189512010-03-04 22:11:00 +0000288/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800289 * relid2channel - Get the channel object given its
290 * child relative id (ie channel id)
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700291 */
Dexuan Cuid43e2fe2015-03-27 09:10:09 -0700292struct vmbus_channel *relid2channel(u32 relid)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700293{
Greg Kroah-Hartmanaded71652009-08-18 15:21:19 -0700294 struct vmbus_channel *channel;
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800295 struct vmbus_channel *found_channel = NULL;
K. Y. Srinivasane68d2972013-05-23 12:02:32 -0700296 struct list_head *cur, *tmp;
297 struct vmbus_channel *cur_sc;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700298
Dexuan Cui85d9aa72016-01-27 22:29:43 -0800299 BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex));
300
Haiyang Zhangda9fcb72011-01-26 12:12:14 -0800301 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800302 if (channel->offermsg.child_relid == relid) {
303 found_channel = channel;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700304 break;
K. Y. Srinivasane68d2972013-05-23 12:02:32 -0700305 } else if (!list_empty(&channel->sc_list)) {
306 /*
307 * Deal with sub-channels.
308 */
309 list_for_each_safe(cur, tmp, &channel->sc_list) {
310 cur_sc = list_entry(cur, struct vmbus_channel,
311 sc_list);
312 if (cur_sc->offermsg.child_relid == relid) {
313 found_channel = cur_sc;
314 break;
315 }
316 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700317 }
318 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700319
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800320 return found_channel;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700321}
322
Hank Janssen3e189512010-03-04 22:11:00 +0000323/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800324 * process_chn_event - Process a channel event notification
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700325 */
Olaf Hering35436482011-04-16 18:50:40 +0200326static void process_chn_event(u32 relid)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700327{
Greg Kroah-Hartmanaded71652009-08-18 15:21:19 -0700328 struct vmbus_channel *channel;
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800329 void *arg;
330 bool read_state;
331 u32 bytes_to_read;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700332
Bill Pemberton454f18a2009-07-27 16:47:24 -0400333 /*
334 * Find the channel based on this relid and invokes the
335 * channel callback to process the event
336 */
K. Y. Srinivasan3a28fa32014-04-08 18:45:54 -0700337 channel = pcpu_relid2channel(relid);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700338
K. Y. Srinivasan37f492c2015-02-28 11:18:21 -0800339 if (!channel)
K. Y. Srinivasan24326032011-08-31 14:35:57 -0700340 return;
K. Y. Srinivasan24326032011-08-31 14:35:57 -0700341
342 /*
343 * A channel once created is persistent even when there
344 * is no driver handling the device. An unloading driver
K. Y. Srinivasand3ba7202014-04-08 18:45:53 -0700345 * sets the onchannel_callback to NULL on the same CPU
346 * as where this interrupt is handled (in an interrupt context).
347 * Thus, checking and invoking the driver specific callback takes
348 * care of orderly unloading of the driver.
K. Y. Srinivasan24326032011-08-31 14:35:57 -0700349 */
350
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800351 if (channel->onchannel_callback != NULL) {
352 arg = channel->channel_callback_context;
353 read_state = channel->batched_reading;
354 /*
355 * This callback reads the messages sent by the host.
356 * We can optimize host to guest signaling by ensuring:
357 * 1. While reading the channel, we disable interrupts from
358 * host.
359 * 2. Ensure that we process all posted messages from the host
360 * before returning from this callback.
361 * 3. Once we return, enable signaling from the host. Once this
362 * state is set we check to see if additional packets are
363 * available to read. In this case we repeat the process.
364 */
365
366 do {
K. Y. Srinivasanaffb1af2014-07-07 16:34:24 -0700367 if (read_state)
368 hv_begin_read(&channel->inbound);
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800369 channel->onchannel_callback(arg);
K. Y. Srinivasanaffb1af2014-07-07 16:34:24 -0700370 if (read_state)
371 bytes_to_read = hv_end_read(&channel->inbound);
372 else
373 bytes_to_read = 0;
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800374 } while (read_state && (bytes_to_read != 0));
K. Y. Srinivasanf878f3d2012-12-01 06:46:35 -0800375 }
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_on_event - Handler for events
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700380 */
K. Y. Srinivasan6de3d6a2011-03-10 14:05:16 -0800381void vmbus_on_event(unsigned long data)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700382{
Olaf Hering35436482011-04-16 18:50:40 +0200383 u32 dword;
K. Y. Srinivasan6552ecd2012-12-01 06:46:49 -0800384 u32 maxdword;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700385 int bit;
Olaf Hering35436482011-04-16 18:50:40 +0200386 u32 relid;
K. Y. Srinivasan6552ecd2012-12-01 06:46:49 -0800387 u32 *recv_int_page = NULL;
388 void *page_addr;
389 int cpu = smp_processor_id();
390 union hv_synic_event_flags *event;
391
Keith Mange6c4e5f92015-05-26 14:23:01 -0700392 if (vmbus_proto_version < VERSION_WIN8) {
K. Y. Srinivasan6552ecd2012-12-01 06:46:49 -0800393 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
394 recv_int_page = vmbus_connection.recv_int_page;
395 } else {
396 /*
397 * When the host is win8 and beyond, the event page
398 * can be directly checked to get the id of the channel
399 * that has the interrupt pending.
400 */
401 maxdword = HV_EVENT_FLAGS_DWORD_COUNT;
402 page_addr = hv_context.synic_event_page[cpu];
403 event = (union hv_synic_event_flags *)page_addr +
404 VMBUS_MESSAGE_SINT;
405 recv_int_page = event->flags32;
406 }
407
408
Hank Janssen3e7ee492009-07-13 16:02:34 -0700409
Bill Pemberton454f18a2009-07-27 16:47:24 -0400410 /* Check events */
Olaf Hering242b45a2011-04-16 18:50:39 +0200411 if (!recv_int_page)
412 return;
413 for (dword = 0; dword < maxdword; dword++) {
414 if (!recv_int_page[dword])
415 continue;
416 for (bit = 0; bit < 32; bit++) {
K. Y. Srinivasand9add43b2011-08-27 11:31:43 -0700417 if (sync_test_and_clear_bit(bit,
418 (unsigned long *)&recv_int_page[dword])) {
Olaf Hering242b45a2011-04-16 18:50:39 +0200419 relid = (dword << 5) + bit;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700420
K. Y. Srinivasand9add43b2011-08-27 11:31:43 -0700421 if (relid == 0)
K. Y. Srinivasan6d81d332011-05-10 07:55:45 -0700422 /*
423 * Special case - vmbus
424 * channel protocol msg
425 */
Olaf Hering242b45a2011-04-16 18:50:39 +0200426 continue;
K. Y. Srinivasand9add43b2011-08-27 11:31:43 -0700427
Olaf Hering35436482011-04-16 18:50:40 +0200428 process_chn_event(relid);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700429 }
Olaf Hering242b45a2011-04-16 18:50:39 +0200430 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700431 }
Hank Janssen3e7ee492009-07-13 16:02:34 -0700432}
433
Hank Janssen3e189512010-03-04 22:11:00 +0000434/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800435 * vmbus_post_msg - Send a msg on the vmbus's message connection
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700436 */
Haiyang Zhangc6977672011-01-26 12:12:08 -0800437int vmbus_post_msg(void *buffer, size_t buflen)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700438{
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800439 union hv_connection_id conn_id;
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -0700440 int ret = 0;
441 int retries = 0;
Haiyang Zhange1c0d822015-03-27 09:10:14 -0700442 u32 msec = 1;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700443
Haiyang Zhang15b2f642011-01-26 12:12:07 -0800444 conn_id.asu32 = 0;
445 conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -0700446
447 /*
448 * hv_post_message() can have transient failures because of
449 * insufficient resources. Retry the operation a couple of
450 * times before giving up.
451 */
Haiyang Zhange1c0d822015-03-27 09:10:14 -0700452 while (retries < 20) {
K. Y. Srinivasanfdeebcc2014-08-27 16:25:31 -0700453 ret = hv_post_message(conn_id, 1, buffer, buflen);
454
455 switch (ret) {
Dexuan Cui89f9f672015-02-27 11:25:59 -0800456 case HV_STATUS_INVALID_CONNECTION_ID:
457 /*
458 * We could get this if we send messages too
459 * frequently.
460 */
461 ret = -EAGAIN;
462 break;
463 case HV_STATUS_INSUFFICIENT_MEMORY:
K. Y. Srinivasanfdeebcc2014-08-27 16:25:31 -0700464 case HV_STATUS_INSUFFICIENT_BUFFERS:
465 ret = -ENOMEM;
K. Y. Srinivasanfdeebcc2014-08-27 16:25:31 -0700466 break;
467 case HV_STATUS_SUCCESS:
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -0700468 return ret;
K. Y. Srinivasanfdeebcc2014-08-27 16:25:31 -0700469 default:
470 pr_err("hv_post_msg() failed; error code:%d\n", ret);
471 return -EINVAL;
472 }
473
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -0700474 retries++;
Haiyang Zhange1c0d822015-03-27 09:10:14 -0700475 msleep(msec);
476 if (msec < 2048)
477 msec *= 2;
K. Y. Srinivasan5289d3d2011-08-25 09:49:01 -0700478 }
479 return ret;
Hank Janssen3e7ee492009-07-13 16:02:34 -0700480}
481
Hank Janssen3e189512010-03-04 22:11:00 +0000482/*
Haiyang Zhangc6977672011-01-26 12:12:08 -0800483 * vmbus_set_event - Send an event notification to the parent
Greg Kroah-Hartmanfd8b85e2009-08-31 11:40:14 -0700484 */
K. Y. Srinivasan1b807e12015-12-21 15:12:20 -0800485void vmbus_set_event(struct vmbus_channel *channel)
Hank Janssen3e7ee492009-07-13 16:02:34 -0700486{
K. Y. Srinivasan21c3bef2012-12-01 06:46:43 -0800487 u32 child_relid = channel->offermsg.child_relid;
Bill Pemberton7c369f42009-07-29 17:00:11 -0400488
K. Y. Srinivasan3be77772012-12-01 06:46:46 -0800489 if (!channel->is_dedicated_interrupt) {
490 /* Each u32 represents 32 channels */
491 sync_set_bit(child_relid & 31,
492 (unsigned long *)vmbus_connection.send_int_page +
493 (child_relid >> 5));
494 }
495
K. Y. Srinivasan1b807e12015-12-21 15:12:20 -0800496 hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL);
Hank Janssen3e7ee492009-07-13 16:02:34 -0700497}
K. Y. Srinivasan5cc47242016-04-02 17:59:49 -0700498EXPORT_SYMBOL_GPL(vmbus_set_event);