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 */
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/wait.h>
26 #include <linux/mm.h>
27 #include <linux/slab.h>
28 #include <linux/vmalloc.h>
29 #include "hv_api.h"
30 #include "logging.h"
31 #include "vmbus_private.h"
32
33
34 struct vmbus_connection vmbus_connection = {
35 .conn_state = DISCONNECTED,
36 .next_gpadl_handle = ATOMIC_INIT(0xE1E10),
37 };
38
39 /*
40 * vmbus_connect - Sends a connect request on the partition service connection
41 */
vmbus_connect(void)42 int vmbus_connect(void)
43 {
44 int ret = 0;
45 struct vmbus_channel_msginfo *msginfo = NULL;
46 struct vmbus_channel_initiate_contact *msg;
47 unsigned long flags;
48
49 /* Make sure we are not connecting or connected */
50 if (vmbus_connection.conn_state != DISCONNECTED)
51 return -1;
52
53 /* Initialize the vmbus connection */
54 vmbus_connection.conn_state = CONNECTING;
55 vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
56 if (!vmbus_connection.work_queue) {
57 ret = -1;
58 goto Cleanup;
59 }
60
61 INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
62 spin_lock_init(&vmbus_connection.channelmsg_lock);
63
64 INIT_LIST_HEAD(&vmbus_connection.chn_list);
65 spin_lock_init(&vmbus_connection.channel_lock);
66
67 /*
68 * Setup the vmbus event connection for channel interrupt
69 * abstraction stuff
70 */
71 vmbus_connection.int_page =
72 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
73 if (vmbus_connection.int_page == NULL) {
74 ret = -1;
75 goto Cleanup;
76 }
77
78 vmbus_connection.recv_int_page = vmbus_connection.int_page;
79 vmbus_connection.send_int_page =
80 (void *)((unsigned long)vmbus_connection.int_page +
81 (PAGE_SIZE >> 1));
82
83 /*
84 * Setup the monitor notification facility. The 1st page for
85 * parent->child and the 2nd page for child->parent
86 */
87 vmbus_connection.monitor_pages =
88 (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 1);
89 if (vmbus_connection.monitor_pages == NULL) {
90 ret = -1;
91 goto Cleanup;
92 }
93
94 msginfo = kzalloc(sizeof(*msginfo) +
95 sizeof(struct vmbus_channel_initiate_contact),
96 GFP_KERNEL);
97 if (msginfo == NULL) {
98 ret = -ENOMEM;
99 goto Cleanup;
100 }
101
102 init_waitqueue_head(&msginfo->waitevent);
103
104 msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;
105
106 msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
107 msg->vmbus_version_requested = VMBUS_REVISION_NUMBER;
108 msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
109 msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages);
110 msg->monitor_page2 = virt_to_phys(
111 (void *)((unsigned long)vmbus_connection.monitor_pages +
112 PAGE_SIZE));
113
114 /*
115 * Add to list before we send the request since we may
116 * receive the response before returning from this routine
117 */
118 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
119 list_add_tail(&msginfo->msglistentry,
120 &vmbus_connection.chn_msg_list);
121
122 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
123
124 DPRINT_DBG(VMBUS, "Vmbus connection - interrupt pfn %llx, "
125 "monitor1 pfn %llx,, monitor2 pfn %llx",
126 msg->interrupt_page, msg->monitor_page1, msg->monitor_page2);
127
128 DPRINT_DBG(VMBUS, "Sending channel initiate msg...");
129 ret = vmbus_post_msg(msg,
130 sizeof(struct vmbus_channel_initiate_contact));
131 if (ret != 0) {
132 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
133 list_del(&msginfo->msglistentry);
134 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
135 flags);
136 goto Cleanup;
137 }
138
139 /* Wait for the connection response */
140 msginfo->wait_condition = 0;
141 wait_event_timeout(msginfo->waitevent, msginfo->wait_condition,
142 msecs_to_jiffies(1000));
143 if (msginfo->wait_condition == 0) {
144 spin_lock_irqsave(&vmbus_connection.channelmsg_lock,
145 flags);
146 list_del(&msginfo->msglistentry);
147 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
148 flags);
149 ret = -ETIMEDOUT;
150 goto Cleanup;
151 }
152
153 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
154 list_del(&msginfo->msglistentry);
155 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
156
157 /* Check if successful */
158 if (msginfo->response.version_response.version_supported) {
159 DPRINT_INFO(VMBUS, "Vmbus connected!!");
160 vmbus_connection.conn_state = CONNECTED;
161
162 } else {
163 DPRINT_ERR(VMBUS, "Vmbus connection failed!!..."
164 "current version (%d) not supported",
165 VMBUS_REVISION_NUMBER);
166 ret = -1;
167 goto Cleanup;
168 }
169
170 kfree(msginfo);
171 return 0;
172
173 Cleanup:
174 vmbus_connection.conn_state = DISCONNECTED;
175
176 if (vmbus_connection.work_queue)
177 destroy_workqueue(vmbus_connection.work_queue);
178
179 if (vmbus_connection.int_page) {
180 free_pages((unsigned long)vmbus_connection.int_page, 0);
181 vmbus_connection.int_page = NULL;
182 }
183
184 if (vmbus_connection.monitor_pages) {
185 free_pages((unsigned long)vmbus_connection.monitor_pages, 1);
186 vmbus_connection.monitor_pages = NULL;
187 }
188
189 kfree(msginfo);
190
191 return ret;
192 }
193
194 /*
195 * vmbus_disconnect -
196 * Sends a disconnect request on the partition service connection
197 */
vmbus_disconnect(void)198 int vmbus_disconnect(void)
199 {
200 int ret = 0;
201 struct vmbus_channel_message_header *msg;
202
203 /* Make sure we are connected */
204 if (vmbus_connection.conn_state != CONNECTED)
205 return -1;
206
207 msg = kzalloc(sizeof(struct vmbus_channel_message_header), GFP_KERNEL);
208 if (!msg)
209 return -ENOMEM;
210
211 msg->msgtype = CHANNELMSG_UNLOAD;
212
213 ret = vmbus_post_msg(msg,
214 sizeof(struct vmbus_channel_message_header));
215 if (ret != 0)
216 goto Cleanup;
217
218 free_pages((unsigned long)vmbus_connection.int_page, 0);
219 free_pages((unsigned long)vmbus_connection.monitor_pages, 1);
220
221 /* TODO: iterate thru the msg list and free up */
222 destroy_workqueue(vmbus_connection.work_queue);
223
224 vmbus_connection.conn_state = DISCONNECTED;
225
226 DPRINT_INFO(VMBUS, "Vmbus disconnected!!");
227
228 Cleanup:
229 kfree(msg);
230 return ret;
231 }
232
233 /*
234 * relid2channel - Get the channel object given its
235 * child relative id (ie channel id)
236 */
relid2channel(u32 relid)237 struct vmbus_channel *relid2channel(u32 relid)
238 {
239 struct vmbus_channel *channel;
240 struct vmbus_channel *found_channel = NULL;
241 unsigned long flags;
242
243 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
244 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
245 if (channel->offermsg.child_relid == relid) {
246 found_channel = channel;
247 break;
248 }
249 }
250 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
251
252 return found_channel;
253 }
254
255 /*
256 * process_chn_event - Process a channel event notification
257 */
process_chn_event(void * context)258 static void process_chn_event(void *context)
259 {
260 struct vmbus_channel *channel;
261 u32 relid = (u32)(unsigned long)context;
262
263 /* ASSERT(relId > 0); */
264
265 /*
266 * Find the channel based on this relid and invokes the
267 * channel callback to process the event
268 */
269 channel = relid2channel(relid);
270
271 if (channel) {
272 vmbus_onchannel_event(channel);
273 /*
274 * WorkQueueQueueWorkItem(channel->dataWorkQueue,
275 * vmbus_onchannel_event,
276 * (void*)channel);
277 */
278 } else {
279 DPRINT_ERR(VMBUS, "channel not found for relid - %d.", relid);
280 }
281 }
282
283 /*
284 * vmbus_on_event - Handler for events
285 */
vmbus_on_event(unsigned long data)286 void vmbus_on_event(unsigned long data)
287 {
288 int dword;
289 int maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
290 int bit;
291 int relid;
292 u32 *recv_int_page = vmbus_connection.recv_int_page;
293
294 /* Check events */
295 if (recv_int_page) {
296 for (dword = 0; dword < maxdword; dword++) {
297 if (recv_int_page[dword]) {
298 for (bit = 0; bit < 32; bit++) {
299 if (sync_test_and_clear_bit(bit,
300 (unsigned long *)
301 &recv_int_page[dword])) {
302 relid = (dword << 5) + bit;
303 DPRINT_DBG(VMBUS, "event detected for relid - %d", relid);
304
305 if (relid == 0) {
306 /* special case - vmbus channel protocol msg */
307 DPRINT_DBG(VMBUS, "invalid relid - %d", relid);
308 continue;
309 } else {
310 /* QueueWorkItem(VmbusProcessEvent, (void*)relid); */
311 /* ret = WorkQueueQueueWorkItem(gVmbusConnection.workQueue, VmbusProcessChannelEvent, (void*)relid); */
312 process_chn_event((void *)
313 (unsigned long)relid);
314 }
315 }
316 }
317 }
318 }
319 }
320 return;
321 }
322
323 /*
324 * vmbus_post_msg - Send a msg on the vmbus's message connection
325 */
vmbus_post_msg(void * buffer,size_t buflen)326 int vmbus_post_msg(void *buffer, size_t buflen)
327 {
328 union hv_connection_id conn_id;
329
330 conn_id.asu32 = 0;
331 conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
332 return hv_post_message(conn_id, 1, buffer, buflen);
333 }
334
335 /*
336 * vmbus_set_event - Send an event notification to the parent
337 */
vmbus_set_event(u32 child_relid)338 int vmbus_set_event(u32 child_relid)
339 {
340 /* Each u32 represents 32 channels */
341 sync_set_bit(child_relid & 31,
342 (unsigned long *)vmbus_connection.send_int_page +
343 (child_relid >> 5));
344
345 return hv_signal_event();
346 }
347