Drivers: hv: Get rid of unnecessary request for offers
[linux-3.10.git] / drivers / hv / hv_util.c
1 /*
2  * Copyright (c) 2010, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  */
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23 #include <linux/kernel.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27 #include <linux/sysctl.h>
28 #include <linux/reboot.h>
29 #include <linux/hyperv.h>
30
31 static void shutdown_onchannelcallback(void *context);
32 static struct hv_util_service util_shutdown = {
33         .util_cb = shutdown_onchannelcallback,
34 };
35
36 static void timesync_onchannelcallback(void *context);
37 static struct hv_util_service util_timesynch = {
38         .util_cb = timesync_onchannelcallback,
39 };
40
41 static void heartbeat_onchannelcallback(void *context);
42 static struct hv_util_service util_heartbeat = {
43         .util_cb = heartbeat_onchannelcallback,
44 };
45
46 static struct hv_util_service util_kvp = {
47         .util_cb = hv_kvp_onchannelcallback,
48         .util_init = hv_kvp_init,
49         .util_deinit = hv_kvp_deinit,
50 };
51
52 static void shutdown_onchannelcallback(void *context)
53 {
54         struct vmbus_channel *channel = context;
55         u32 recvlen;
56         u64 requestid;
57         u8  execute_shutdown = false;
58         u8  *shut_txf_buf = util_shutdown.recv_buffer;
59
60         struct shutdown_msg_data *shutdown_msg;
61
62         struct icmsg_hdr *icmsghdrp;
63         struct icmsg_negotiate *negop = NULL;
64
65         vmbus_recvpacket(channel, shut_txf_buf,
66                          PAGE_SIZE, &recvlen, &requestid);
67
68         if (recvlen > 0) {
69                 icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
70                         sizeof(struct vmbuspipe_hdr)];
71
72                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
73                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
74                                         shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
75                 } else {
76                         shutdown_msg =
77                                 (struct shutdown_msg_data *)&shut_txf_buf[
78                                         sizeof(struct vmbuspipe_hdr) +
79                                         sizeof(struct icmsg_hdr)];
80
81                         switch (shutdown_msg->flags) {
82                         case 0:
83                         case 1:
84                                 icmsghdrp->status = HV_S_OK;
85                                 execute_shutdown = true;
86
87                                 pr_info("Shutdown request received -"
88                                             " graceful shutdown initiated\n");
89                                 break;
90                         default:
91                                 icmsghdrp->status = HV_E_FAIL;
92                                 execute_shutdown = false;
93
94                                 pr_info("Shutdown request received -"
95                                             " Invalid request\n");
96                                 break;
97                         }
98                 }
99
100                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
101                         | ICMSGHDRFLAG_RESPONSE;
102
103                 vmbus_sendpacket(channel, shut_txf_buf,
104                                        recvlen, requestid,
105                                        VM_PKT_DATA_INBAND, 0);
106         }
107
108         if (execute_shutdown == true)
109                 orderly_poweroff(true);
110 }
111
112 /*
113  * Set guest time to host UTC time.
114  */
115 static inline void do_adj_guesttime(u64 hosttime)
116 {
117         s64 host_tns;
118         struct timespec host_ts;
119
120         host_tns = (hosttime - WLTIMEDELTA) * 100;
121         host_ts = ns_to_timespec(host_tns);
122
123         do_settimeofday(&host_ts);
124 }
125
126 /*
127  * Set the host time in a process context.
128  */
129
130 struct adj_time_work {
131         struct work_struct work;
132         u64     host_time;
133 };
134
135 static void hv_set_host_time(struct work_struct *work)
136 {
137         struct adj_time_work    *wrk;
138
139         wrk = container_of(work, struct adj_time_work, work);
140         do_adj_guesttime(wrk->host_time);
141         kfree(wrk);
142 }
143
144 /*
145  * Synchronize time with host after reboot, restore, etc.
146  *
147  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
148  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
149  * message after the timesync channel is opened. Since the hv_utils module is
150  * loaded after hv_vmbus, the first message is usually missed. The other
151  * thing is, systime is automatically set to emulated hardware clock which may
152  * not be UTC time or in the same time zone. So, to override these effects, we
153  * use the first 50 time samples for initial system time setting.
154  */
155 static inline void adj_guesttime(u64 hosttime, u8 flags)
156 {
157         struct adj_time_work    *wrk;
158         static s32 scnt = 50;
159
160         wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
161         if (wrk == NULL)
162                 return;
163
164         wrk->host_time = hosttime;
165         if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
166                 INIT_WORK(&wrk->work, hv_set_host_time);
167                 schedule_work(&wrk->work);
168                 return;
169         }
170
171         if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
172                 scnt--;
173                 INIT_WORK(&wrk->work, hv_set_host_time);
174                 schedule_work(&wrk->work);
175         } else
176                 kfree(wrk);
177 }
178
179 /*
180  * Time Sync Channel message handler.
181  */
182 static void timesync_onchannelcallback(void *context)
183 {
184         struct vmbus_channel *channel = context;
185         u32 recvlen;
186         u64 requestid;
187         struct icmsg_hdr *icmsghdrp;
188         struct ictimesync_data *timedatap;
189         u8 *time_txf_buf = util_timesynch.recv_buffer;
190
191         vmbus_recvpacket(channel, time_txf_buf,
192                          PAGE_SIZE, &recvlen, &requestid);
193
194         if (recvlen > 0) {
195                 icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
196                                 sizeof(struct vmbuspipe_hdr)];
197
198                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
199                         vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
200                                                 MAX_SRV_VER, MAX_SRV_VER);
201                 } else {
202                         timedatap = (struct ictimesync_data *)&time_txf_buf[
203                                 sizeof(struct vmbuspipe_hdr) +
204                                 sizeof(struct icmsg_hdr)];
205                         adj_guesttime(timedatap->parenttime, timedatap->flags);
206                 }
207
208                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
209                         | ICMSGHDRFLAG_RESPONSE;
210
211                 vmbus_sendpacket(channel, time_txf_buf,
212                                 recvlen, requestid,
213                                 VM_PKT_DATA_INBAND, 0);
214         }
215 }
216
217 /*
218  * Heartbeat functionality.
219  * Every two seconds, Hyper-V send us a heartbeat request message.
220  * we respond to this message, and Hyper-V knows we are alive.
221  */
222 static void heartbeat_onchannelcallback(void *context)
223 {
224         struct vmbus_channel *channel = context;
225         u32 recvlen;
226         u64 requestid;
227         struct icmsg_hdr *icmsghdrp;
228         struct heartbeat_msg_data *heartbeat_msg;
229         u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
230
231         vmbus_recvpacket(channel, hbeat_txf_buf,
232                          PAGE_SIZE, &recvlen, &requestid);
233
234         if (recvlen > 0) {
235                 icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
236                                 sizeof(struct vmbuspipe_hdr)];
237
238                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
239                         vmbus_prep_negotiate_resp(icmsghdrp, NULL,
240                                 hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
241                 } else {
242                         heartbeat_msg =
243                                 (struct heartbeat_msg_data *)&hbeat_txf_buf[
244                                         sizeof(struct vmbuspipe_hdr) +
245                                         sizeof(struct icmsg_hdr)];
246
247                         heartbeat_msg->seq_num += 1;
248                 }
249
250                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
251                         | ICMSGHDRFLAG_RESPONSE;
252
253                 vmbus_sendpacket(channel, hbeat_txf_buf,
254                                        recvlen, requestid,
255                                        VM_PKT_DATA_INBAND, 0);
256         }
257 }
258
259 static int util_probe(struct hv_device *dev,
260                         const struct hv_vmbus_device_id *dev_id)
261 {
262         struct hv_util_service *srv =
263                 (struct hv_util_service *)dev_id->driver_data;
264         int ret;
265
266         srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
267         if (!srv->recv_buffer)
268                 return -ENOMEM;
269         if (srv->util_init) {
270                 ret = srv->util_init(srv);
271                 if (ret) {
272                         ret = -ENODEV;
273                         goto error1;
274                 }
275         }
276
277         /*
278          * The set of services managed by the util driver are not performance
279          * critical and do not need batched reading. Furthermore, some services
280          * such as KVP can only handle one message from the host at a time.
281          * Turn off batched reading for all util drivers before we open the
282          * channel.
283          */
284
285         set_channel_read_state(dev->channel, false);
286
287         ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
288                         srv->util_cb, dev->channel);
289         if (ret)
290                 goto error;
291
292         hv_set_drvdata(dev, srv);
293         return 0;
294
295 error:
296         if (srv->util_deinit)
297                 srv->util_deinit();
298 error1:
299         kfree(srv->recv_buffer);
300         return ret;
301 }
302
303 static int util_remove(struct hv_device *dev)
304 {
305         struct hv_util_service *srv = hv_get_drvdata(dev);
306
307         vmbus_close(dev->channel);
308         if (srv->util_deinit)
309                 srv->util_deinit();
310         kfree(srv->recv_buffer);
311
312         return 0;
313 }
314
315 static const struct hv_vmbus_device_id id_table[] = {
316         /* Shutdown guid */
317         { VMBUS_DEVICE(0x31, 0x60, 0x0B, 0X0E, 0x13, 0x52, 0x34, 0x49,
318                        0x81, 0x8B, 0x38, 0XD9, 0x0C, 0xED, 0x39, 0xDB)
319           .driver_data = (unsigned long)&util_shutdown },
320         /* Time synch guid */
321         { VMBUS_DEVICE(0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
322                        0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf)
323           .driver_data = (unsigned long)&util_timesynch },
324         /* Heartbeat guid */
325         { VMBUS_DEVICE(0x39, 0x4f, 0x16, 0x57, 0x15, 0x91, 0x78, 0x4e,
326                        0xab, 0x55, 0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d)
327           .driver_data = (unsigned long)&util_heartbeat },
328         /* KVP guid */
329         { VMBUS_DEVICE(0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
330                        0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6)
331           .driver_data = (unsigned long)&util_kvp },
332         { },
333 };
334
335 MODULE_DEVICE_TABLE(vmbus, id_table);
336
337 /* The one and only one */
338 static  struct hv_driver util_drv = {
339         .name = "hv_util",
340         .id_table = id_table,
341         .probe =  util_probe,
342         .remove =  util_remove,
343 };
344
345 static int __init init_hyperv_utils(void)
346 {
347         pr_info("Registering HyperV Utility Driver\n");
348
349         return vmbus_driver_register(&util_drv);
350 }
351
352 static void exit_hyperv_utils(void)
353 {
354         pr_info("De-Registered HyperV Utility Driver\n");
355
356         vmbus_driver_unregister(&util_drv);
357 }
358
359 module_init(init_hyperv_utils);
360 module_exit(exit_hyperv_utils);
361
362 MODULE_DESCRIPTION("Hyper-V Utilities");
363 MODULE_VERSION(HV_DRV_VERSION);
364 MODULE_LICENSE("GPL");