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Commit | Line | Data |
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3e7ee490 HJ |
1 | /* |
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 | */ | |
0a46618d HJ |
23 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
24 | ||
a0086dc5 | 25 | #include <linux/kernel.h> |
0c3b7b2f S |
26 | #include <linux/sched.h> |
27 | #include <linux/wait.h> | |
5289d3d1 | 28 | #include <linux/delay.h> |
a0086dc5 | 29 | #include <linux/mm.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
a0086dc5 | 31 | #include <linux/vmalloc.h> |
46a97191 | 32 | #include <linux/hyperv.h> |
37f7278b | 33 | #include <linux/export.h> |
407dd164 | 34 | #include <asm/hyperv.h> |
0f2a6619 | 35 | #include "hyperv_vmbus.h" |
3e7ee490 | 36 | |
3e7ee490 | 37 | |
da9fcb72 HZ |
38 | struct vmbus_connection vmbus_connection = { |
39 | .conn_state = DISCONNECTED, | |
40 | .next_gpadl_handle = ATOMIC_INIT(0xE1E10), | |
3e7ee490 HJ |
41 | }; |
42 | ||
37f7278b S |
43 | /* |
44 | * Negotiated protocol version with the host. | |
45 | */ | |
46 | __u32 vmbus_proto_version; | |
47 | EXPORT_SYMBOL_GPL(vmbus_proto_version); | |
48 | ||
610071c3 S |
49 | static __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 | ||
64 | static 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 { | |
123 | pr_err("Unable to connect, " | |
124 | "Version %d not supported by Hyper-V\n", | |
125 | version); | |
126 | return -ECONNREFUSED; | |
127 | } | |
128 | ||
129 | return ret; | |
130 | } | |
131 | ||
3e189519 | 132 | /* |
c6977677 | 133 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 134 | */ |
c6977677 | 135 | int vmbus_connect(void) |
3e7ee490 | 136 | { |
fd8b85ea | 137 | int ret = 0; |
15b2f647 | 138 | struct vmbus_channel_msginfo *msginfo = NULL; |
610071c3 | 139 | __u32 version; |
3e7ee490 | 140 | |
454f18a9 | 141 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
142 | vmbus_connection.conn_state = CONNECTING; |
143 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
144 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 145 | ret = -ENOMEM; |
b0043863 | 146 | goto cleanup; |
de65a384 | 147 | } |
3e7ee490 | 148 | |
da9fcb72 | 149 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 150 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 151 | |
da9fcb72 | 152 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
15b2f647 | 153 | spin_lock_init(&vmbus_connection.channel_lock); |
3e7ee490 | 154 | |
454f18a9 BP |
155 | /* |
156 | * Setup the vmbus event connection for channel interrupt | |
157 | * abstraction stuff | |
158 | */ | |
df3493e0 S |
159 | vmbus_connection.int_page = |
160 | (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); | |
da9fcb72 | 161 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 162 | ret = -ENOMEM; |
b0043863 | 163 | goto cleanup; |
3e7ee490 HJ |
164 | } |
165 | ||
da9fcb72 HZ |
166 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
167 | vmbus_connection.send_int_page = | |
168 | (void *)((unsigned long)vmbus_connection.int_page + | |
fd8b85ea | 169 | (PAGE_SIZE >> 1)); |
3e7ee490 | 170 | |
fd8b85ea GKH |
171 | /* |
172 | * Setup the monitor notification facility. The 1st page for | |
173 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 174 | */ |
df3493e0 S |
175 | vmbus_connection.monitor_pages = |
176 | (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 1); | |
da9fcb72 | 177 | if (vmbus_connection.monitor_pages == NULL) { |
3a7546d9 | 178 | ret = -ENOMEM; |
b0043863 | 179 | goto cleanup; |
3e7ee490 HJ |
180 | } |
181 | ||
15b2f647 | 182 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
183 | sizeof(struct vmbus_channel_initiate_contact), |
184 | GFP_KERNEL); | |
15b2f647 | 185 | if (msginfo == NULL) { |
8cad0af9 | 186 | ret = -ENOMEM; |
b0043863 | 187 | goto cleanup; |
3e7ee490 HJ |
188 | } |
189 | ||
454f18a9 | 190 | /* |
610071c3 S |
191 | * Negotiate a compatible VMBUS version number with the |
192 | * host. We start with the highest number we can support | |
193 | * and work our way down until we negotiate a compatible | |
194 | * version. | |
454f18a9 | 195 | */ |
3e7ee490 | 196 | |
610071c3 | 197 | version = VERSION_WS2008; |
3e7ee490 | 198 | |
610071c3 S |
199 | do { |
200 | ret = vmbus_negotiate_version(msginfo, version); | |
201 | if (ret == 0) | |
202 | break; | |
3e7ee490 | 203 | |
610071c3 S |
204 | version = vmbus_get_next_version(version); |
205 | } while (version != VERSION_INVAL); | |
3e7ee490 | 206 | |
610071c3 | 207 | if (version == VERSION_INVAL) |
b0043863 | 208 | goto cleanup; |
3e7ee490 | 209 | |
37f7278b S |
210 | vmbus_proto_version = version; |
211 | pr_info("Negotiated host information %d\n", version); | |
15b2f647 | 212 | kfree(msginfo); |
3e7ee490 HJ |
213 | return 0; |
214 | ||
b0043863 | 215 | cleanup: |
da9fcb72 | 216 | vmbus_connection.conn_state = DISCONNECTED; |
3e7ee490 | 217 | |
da9fcb72 HZ |
218 | if (vmbus_connection.work_queue) |
219 | destroy_workqueue(vmbus_connection.work_queue); | |
3e7ee490 | 220 | |
da9fcb72 | 221 | if (vmbus_connection.int_page) { |
df3493e0 | 222 | free_pages((unsigned long)vmbus_connection.int_page, 0); |
da9fcb72 | 223 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
224 | } |
225 | ||
da9fcb72 | 226 | if (vmbus_connection.monitor_pages) { |
df3493e0 | 227 | free_pages((unsigned long)vmbus_connection.monitor_pages, 1); |
da9fcb72 | 228 | vmbus_connection.monitor_pages = NULL; |
3e7ee490 HJ |
229 | } |
230 | ||
dd9b15dc | 231 | kfree(msginfo); |
3e7ee490 | 232 | |
3e7ee490 HJ |
233 | return ret; |
234 | } | |
235 | ||
3e7ee490 | 236 | |
3e189519 | 237 | /* |
c6977677 HZ |
238 | * relid2channel - Get the channel object given its |
239 | * child relative id (ie channel id) | |
fd8b85ea | 240 | */ |
c6977677 | 241 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 242 | { |
aded7165 | 243 | struct vmbus_channel *channel; |
15b2f647 | 244 | struct vmbus_channel *found_channel = NULL; |
0f5e44ca | 245 | unsigned long flags; |
3e7ee490 | 246 | |
15b2f647 | 247 | spin_lock_irqsave(&vmbus_connection.channel_lock, flags); |
da9fcb72 | 248 | list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |
15b2f647 HZ |
249 | if (channel->offermsg.child_relid == relid) { |
250 | found_channel = channel; | |
3e7ee490 HJ |
251 | break; |
252 | } | |
253 | } | |
15b2f647 | 254 | spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); |
3e7ee490 | 255 | |
15b2f647 | 256 | return found_channel; |
3e7ee490 HJ |
257 | } |
258 | ||
3e189519 | 259 | /* |
c6977677 | 260 | * process_chn_event - Process a channel event notification |
fd8b85ea | 261 | */ |
35436487 | 262 | static void process_chn_event(u32 relid) |
3e7ee490 | 263 | { |
aded7165 | 264 | struct vmbus_channel *channel; |
dad76bf7 | 265 | unsigned long flags; |
f878f3d5 S |
266 | void *arg; |
267 | bool read_state; | |
268 | u32 bytes_to_read; | |
3e7ee490 | 269 | |
454f18a9 BP |
270 | /* |
271 | * Find the channel based on this relid and invokes the | |
272 | * channel callback to process the event | |
273 | */ | |
c6977677 | 274 | channel = relid2channel(relid); |
3e7ee490 | 275 | |
24326039 S |
276 | if (!channel) { |
277 | pr_err("channel not found for relid - %u\n", relid); | |
278 | return; | |
279 | } | |
280 | ||
281 | /* | |
282 | * A channel once created is persistent even when there | |
283 | * is no driver handling the device. An unloading driver | |
284 | * sets the onchannel_callback to NULL under the | |
285 | * protection of the channel inbound_lock. Thus, checking | |
286 | * and invoking the driver specific callback takes care of | |
287 | * orderly unloading of the driver. | |
288 | */ | |
289 | ||
dad76bf7 | 290 | spin_lock_irqsave(&channel->inbound_lock, flags); |
f878f3d5 S |
291 | if (channel->onchannel_callback != NULL) { |
292 | arg = channel->channel_callback_context; | |
293 | read_state = channel->batched_reading; | |
294 | /* | |
295 | * This callback reads the messages sent by the host. | |
296 | * We can optimize host to guest signaling by ensuring: | |
297 | * 1. While reading the channel, we disable interrupts from | |
298 | * host. | |
299 | * 2. Ensure that we process all posted messages from the host | |
300 | * before returning from this callback. | |
301 | * 3. Once we return, enable signaling from the host. Once this | |
302 | * state is set we check to see if additional packets are | |
303 | * available to read. In this case we repeat the process. | |
304 | */ | |
305 | ||
306 | do { | |
307 | hv_begin_read(&channel->inbound); | |
308 | channel->onchannel_callback(arg); | |
309 | bytes_to_read = hv_end_read(&channel->inbound); | |
310 | } while (read_state && (bytes_to_read != 0)); | |
311 | } else { | |
24326039 | 312 | pr_err("no channel callback for relid - %u\n", relid); |
f878f3d5 | 313 | } |
d9add43b | 314 | |
dad76bf7 | 315 | spin_unlock_irqrestore(&channel->inbound_lock, flags); |
3e7ee490 HJ |
316 | } |
317 | ||
3e189519 | 318 | /* |
c6977677 | 319 | * vmbus_on_event - Handler for events |
fd8b85ea | 320 | */ |
6de3d6aa | 321 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 322 | { |
35436487 OH |
323 | u32 dword; |
324 | u32 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5; | |
3e7ee490 | 325 | int bit; |
35436487 | 326 | u32 relid; |
da9fcb72 | 327 | u32 *recv_int_page = vmbus_connection.recv_int_page; |
3e7ee490 | 328 | |
454f18a9 | 329 | /* Check events */ |
242b45aa OH |
330 | if (!recv_int_page) |
331 | return; | |
332 | for (dword = 0; dword < maxdword; dword++) { | |
333 | if (!recv_int_page[dword]) | |
334 | continue; | |
335 | for (bit = 0; bit < 32; bit++) { | |
d9add43b S |
336 | if (sync_test_and_clear_bit(bit, |
337 | (unsigned long *)&recv_int_page[dword])) { | |
242b45aa OH |
338 | relid = (dword << 5) + bit; |
339 | ||
d9add43b | 340 | if (relid == 0) |
6d81d330 S |
341 | /* |
342 | * Special case - vmbus | |
343 | * channel protocol msg | |
344 | */ | |
242b45aa | 345 | continue; |
d9add43b | 346 | |
35436487 | 347 | process_chn_event(relid); |
3e7ee490 | 348 | } |
242b45aa | 349 | } |
3e7ee490 | 350 | } |
3e7ee490 HJ |
351 | } |
352 | ||
3e189519 | 353 | /* |
c6977677 | 354 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 355 | */ |
c6977677 | 356 | int vmbus_post_msg(void *buffer, size_t buflen) |
3e7ee490 | 357 | { |
15b2f647 | 358 | union hv_connection_id conn_id; |
5289d3d1 S |
359 | int ret = 0; |
360 | int retries = 0; | |
3e7ee490 | 361 | |
15b2f647 HZ |
362 | conn_id.asu32 = 0; |
363 | conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID; | |
5289d3d1 S |
364 | |
365 | /* | |
366 | * hv_post_message() can have transient failures because of | |
367 | * insufficient resources. Retry the operation a couple of | |
368 | * times before giving up. | |
369 | */ | |
370 | while (retries < 3) { | |
371 | ret = hv_post_message(conn_id, 1, buffer, buflen); | |
372 | if (ret != HV_STATUS_INSUFFICIENT_BUFFERS) | |
373 | return ret; | |
374 | retries++; | |
375 | msleep(100); | |
376 | } | |
377 | return ret; | |
3e7ee490 HJ |
378 | } |
379 | ||
3e189519 | 380 | /* |
c6977677 | 381 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 382 | */ |
21c3bef5 | 383 | int vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 384 | { |
21c3bef5 | 385 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 386 | |
3be77774 S |
387 | if (!channel->is_dedicated_interrupt) { |
388 | /* Each u32 represents 32 channels */ | |
389 | sync_set_bit(child_relid & 31, | |
390 | (unsigned long *)vmbus_connection.send_int_page + | |
391 | (child_relid >> 5)); | |
392 | } | |
393 | ||
394 | return hv_signal_event(channel->sig_event); | |
3e7ee490 | 395 | } |