xref: /openbmc/linux/drivers/hv/hv_util.c (revision 55e43d6abd078ed6d219902ce8cb4d68e3c993ba)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2010, Microsoft Corporation.
4  *
5  * Authors:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  *   Hank Janssen  <hjanssen@microsoft.com>
8  */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/sysctl.h>
16 #include <linux/reboot.h>
17 #include <linux/hyperv.h>
18 #include <linux/clockchips.h>
19 #include <linux/ptp_clock_kernel.h>
20 #include <asm/mshyperv.h>
21 
22 #include "hyperv_vmbus.h"
23 
24 #define SD_MAJOR	3
25 #define SD_MINOR	0
26 #define SD_MINOR_1	1
27 #define SD_MINOR_2	2
28 #define SD_VERSION_3_1	(SD_MAJOR << 16 | SD_MINOR_1)
29 #define SD_VERSION_3_2	(SD_MAJOR << 16 | SD_MINOR_2)
30 #define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)
31 
32 #define SD_MAJOR_1	1
33 #define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)
34 
35 #define TS_MAJOR	4
36 #define TS_MINOR	0
37 #define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)
38 
39 #define TS_MAJOR_1	1
40 #define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)
41 
42 #define TS_MAJOR_3	3
43 #define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)
44 
45 #define HB_MAJOR	3
46 #define HB_MINOR	0
47 #define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)
48 
49 #define HB_MAJOR_1	1
50 #define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)
51 
52 static int sd_srv_version;
53 static int ts_srv_version;
54 static int hb_srv_version;
55 
56 #define SD_VER_COUNT 4
57 static const int sd_versions[] = {
58 	SD_VERSION_3_2,
59 	SD_VERSION_3_1,
60 	SD_VERSION,
61 	SD_VERSION_1
62 };
63 
64 #define TS_VER_COUNT 3
65 static const int ts_versions[] = {
66 	TS_VERSION,
67 	TS_VERSION_3,
68 	TS_VERSION_1
69 };
70 
71 #define HB_VER_COUNT 2
72 static const int hb_versions[] = {
73 	HB_VERSION,
74 	HB_VERSION_1
75 };
76 
77 #define FW_VER_COUNT 2
78 static const int fw_versions[] = {
79 	UTIL_FW_VERSION,
80 	UTIL_WS2K8_FW_VERSION
81 };
82 
83 /*
84  * Send the "hibernate" udev event in a thread context.
85  */
86 struct hibernate_work_context {
87 	struct work_struct work;
88 	struct hv_device *dev;
89 };
90 
91 static struct hibernate_work_context hibernate_context;
92 static bool hibernation_supported;
93 
send_hibernate_uevent(struct work_struct * work)94 static void send_hibernate_uevent(struct work_struct *work)
95 {
96 	char *uevent_env[2] = { "EVENT=hibernate", NULL };
97 	struct hibernate_work_context *ctx;
98 
99 	ctx = container_of(work, struct hibernate_work_context, work);
100 
101 	kobject_uevent_env(&ctx->dev->device.kobj, KOBJ_CHANGE, uevent_env);
102 
103 	pr_info("Sent hibernation uevent\n");
104 }
105 
hv_shutdown_init(struct hv_util_service * srv)106 static int hv_shutdown_init(struct hv_util_service *srv)
107 {
108 	struct vmbus_channel *channel = srv->channel;
109 
110 	INIT_WORK(&hibernate_context.work, send_hibernate_uevent);
111 	hibernate_context.dev = channel->device_obj;
112 
113 	hibernation_supported = hv_is_hibernation_supported();
114 
115 	return 0;
116 }
117 
118 static void shutdown_onchannelcallback(void *context);
119 static struct hv_util_service util_shutdown = {
120 	.util_cb = shutdown_onchannelcallback,
121 	.util_init = hv_shutdown_init,
122 };
123 
124 static int hv_timesync_init(struct hv_util_service *srv);
125 static int hv_timesync_pre_suspend(void);
126 static void hv_timesync_deinit(void);
127 
128 static void timesync_onchannelcallback(void *context);
129 static struct hv_util_service util_timesynch = {
130 	.util_cb = timesync_onchannelcallback,
131 	.util_init = hv_timesync_init,
132 	.util_pre_suspend = hv_timesync_pre_suspend,
133 	.util_deinit = hv_timesync_deinit,
134 };
135 
136 static void heartbeat_onchannelcallback(void *context);
137 static struct hv_util_service util_heartbeat = {
138 	.util_cb = heartbeat_onchannelcallback,
139 };
140 
141 static struct hv_util_service util_kvp = {
142 	.util_cb = hv_kvp_onchannelcallback,
143 	.util_init = hv_kvp_init,
144 	.util_init_transport = hv_kvp_init_transport,
145 	.util_pre_suspend = hv_kvp_pre_suspend,
146 	.util_pre_resume = hv_kvp_pre_resume,
147 	.util_deinit = hv_kvp_deinit,
148 };
149 
150 static struct hv_util_service util_vss = {
151 	.util_cb = hv_vss_onchannelcallback,
152 	.util_init = hv_vss_init,
153 	.util_init_transport = hv_vss_init_transport,
154 	.util_pre_suspend = hv_vss_pre_suspend,
155 	.util_pre_resume = hv_vss_pre_resume,
156 	.util_deinit = hv_vss_deinit,
157 };
158 
159 static struct hv_util_service util_fcopy = {
160 	.util_cb = hv_fcopy_onchannelcallback,
161 	.util_init = hv_fcopy_init,
162 	.util_pre_suspend = hv_fcopy_pre_suspend,
163 	.util_pre_resume = hv_fcopy_pre_resume,
164 	.util_deinit = hv_fcopy_deinit,
165 };
166 
perform_shutdown(struct work_struct * dummy)167 static void perform_shutdown(struct work_struct *dummy)
168 {
169 	orderly_poweroff(true);
170 }
171 
perform_restart(struct work_struct * dummy)172 static void perform_restart(struct work_struct *dummy)
173 {
174 	orderly_reboot();
175 }
176 
177 /*
178  * Perform the shutdown operation in a thread context.
179  */
180 static DECLARE_WORK(shutdown_work, perform_shutdown);
181 
182 /*
183  * Perform the restart operation in a thread context.
184  */
185 static DECLARE_WORK(restart_work, perform_restart);
186 
shutdown_onchannelcallback(void * context)187 static void shutdown_onchannelcallback(void *context)
188 {
189 	struct vmbus_channel *channel = context;
190 	struct work_struct *work = NULL;
191 	u32 recvlen;
192 	u64 requestid;
193 	u8  *shut_txf_buf = util_shutdown.recv_buffer;
194 
195 	struct shutdown_msg_data *shutdown_msg;
196 
197 	struct icmsg_hdr *icmsghdrp;
198 
199 	if (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
200 		pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
201 		return;
202 	}
203 
204 	if (!recvlen)
205 		return;
206 
207 	/* Ensure recvlen is big enough to read header data */
208 	if (recvlen < ICMSG_HDR) {
209 		pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
210 				   recvlen);
211 		return;
212 	}
213 
214 	icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[sizeof(struct vmbuspipe_hdr)];
215 
216 	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
217 		if (vmbus_prep_negotiate_resp(icmsghdrp,
218 				shut_txf_buf, recvlen,
219 				fw_versions, FW_VER_COUNT,
220 				sd_versions, SD_VER_COUNT,
221 				NULL, &sd_srv_version)) {
222 			pr_info("Shutdown IC version %d.%d\n",
223 				sd_srv_version >> 16,
224 				sd_srv_version & 0xFFFF);
225 		}
226 	} else if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
227 		/* Ensure recvlen is big enough to contain shutdown_msg_data struct */
228 		if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
229 			pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
230 					   recvlen);
231 			return;
232 		}
233 
234 		shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];
235 
236 		/*
237 		 * shutdown_msg->flags can be 0(shut down), 2(reboot),
238 		 * or 4(hibernate). It may bitwise-OR 1, which means
239 		 * performing the request by force. Linux always tries
240 		 * to perform the request by force.
241 		 */
242 		switch (shutdown_msg->flags) {
243 		case 0:
244 		case 1:
245 			icmsghdrp->status = HV_S_OK;
246 			work = &shutdown_work;
247 			pr_info("Shutdown request received - graceful shutdown initiated\n");
248 			break;
249 		case 2:
250 		case 3:
251 			icmsghdrp->status = HV_S_OK;
252 			work = &restart_work;
253 			pr_info("Restart request received - graceful restart initiated\n");
254 			break;
255 		case 4:
256 		case 5:
257 			pr_info("Hibernation request received\n");
258 			icmsghdrp->status = hibernation_supported ?
259 				HV_S_OK : HV_E_FAIL;
260 			if (hibernation_supported)
261 				work = &hibernate_context.work;
262 			break;
263 		default:
264 			icmsghdrp->status = HV_E_FAIL;
265 			pr_info("Shutdown request received - Invalid request\n");
266 			break;
267 		}
268 	} else {
269 		icmsghdrp->status = HV_E_FAIL;
270 		pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
271 				   icmsghdrp->icmsgtype);
272 	}
273 
274 	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
275 		| ICMSGHDRFLAG_RESPONSE;
276 
277 	vmbus_sendpacket(channel, shut_txf_buf,
278 			 recvlen, requestid,
279 			 VM_PKT_DATA_INBAND, 0);
280 
281 	if (work)
282 		schedule_work(work);
283 }
284 
285 /*
286  * Set the host time in a process context.
287  */
288 static struct work_struct adj_time_work;
289 
290 /*
291  * The last time sample, received from the host. PTP device responds to
292  * requests by using this data and the current partition-wide time reference
293  * count.
294  */
295 static struct {
296 	u64				host_time;
297 	u64				ref_time;
298 	spinlock_t			lock;
299 } host_ts;
300 
reftime_to_ns(u64 reftime)301 static inline u64 reftime_to_ns(u64 reftime)
302 {
303 	return (reftime - WLTIMEDELTA) * 100;
304 }
305 
306 /*
307  * Hard coded threshold for host timesync delay: 600 seconds
308  */
309 static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;
310 
hv_get_adj_host_time(struct timespec64 * ts)311 static int hv_get_adj_host_time(struct timespec64 *ts)
312 {
313 	u64 newtime, reftime, timediff_adj;
314 	unsigned long flags;
315 	int ret = 0;
316 
317 	spin_lock_irqsave(&host_ts.lock, flags);
318 	reftime = hv_read_reference_counter();
319 
320 	/*
321 	 * We need to let the caller know that last update from host
322 	 * is older than the max allowable threshold. clock_gettime()
323 	 * and PTP ioctl do not have a documented error that we could
324 	 * return for this specific case. Use ESTALE to report this.
325 	 */
326 	timediff_adj = reftime - host_ts.ref_time;
327 	if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
328 		pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
329 			     (timediff_adj * 100));
330 		ret = -ESTALE;
331 	}
332 
333 	newtime = host_ts.host_time + timediff_adj;
334 	*ts = ns_to_timespec64(reftime_to_ns(newtime));
335 	spin_unlock_irqrestore(&host_ts.lock, flags);
336 
337 	return ret;
338 }
339 
hv_set_host_time(struct work_struct * work)340 static void hv_set_host_time(struct work_struct *work)
341 {
342 
343 	struct timespec64 ts;
344 
345 	if (!hv_get_adj_host_time(&ts))
346 		do_settimeofday64(&ts);
347 }
348 
349 /*
350  * Synchronize time with host after reboot, restore, etc.
351  *
352  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
353  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
354  * message after the timesync channel is opened. Since the hv_utils module is
355  * loaded after hv_vmbus, the first message is usually missed. This bit is
356  * considered a hard request to discipline the clock.
357  *
358  * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
359  * typically used as a hint to the guest. The guest is under no obligation
360  * to discipline the clock.
361  */
adj_guesttime(u64 hosttime,u64 reftime,u8 adj_flags)362 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
363 {
364 	unsigned long flags;
365 	u64 cur_reftime;
366 
367 	/*
368 	 * Save the adjusted time sample from the host and the snapshot
369 	 * of the current system time.
370 	 */
371 	spin_lock_irqsave(&host_ts.lock, flags);
372 
373 	cur_reftime = hv_read_reference_counter();
374 	host_ts.host_time = hosttime;
375 	host_ts.ref_time = cur_reftime;
376 
377 	/*
378 	 * TimeSync v4 messages contain reference time (guest's Hyper-V
379 	 * clocksource read when the time sample was generated), we can
380 	 * improve the precision by adding the delta between now and the
381 	 * time of generation. For older protocols we set
382 	 * reftime == cur_reftime on call.
383 	 */
384 	host_ts.host_time += (cur_reftime - reftime);
385 
386 	spin_unlock_irqrestore(&host_ts.lock, flags);
387 
388 	/* Schedule work to do do_settimeofday64() */
389 	if (adj_flags & ICTIMESYNCFLAG_SYNC)
390 		schedule_work(&adj_time_work);
391 }
392 
393 /*
394  * Time Sync Channel message handler.
395  */
timesync_onchannelcallback(void * context)396 static void timesync_onchannelcallback(void *context)
397 {
398 	struct vmbus_channel *channel = context;
399 	u32 recvlen;
400 	u64 requestid;
401 	struct icmsg_hdr *icmsghdrp;
402 	struct ictimesync_data *timedatap;
403 	struct ictimesync_ref_data *refdata;
404 	u8 *time_txf_buf = util_timesynch.recv_buffer;
405 
406 	/*
407 	 * Drain the ring buffer and use the last packet to update
408 	 * host_ts
409 	 */
410 	while (1) {
411 		int ret = vmbus_recvpacket(channel, time_txf_buf,
412 					   HV_HYP_PAGE_SIZE, &recvlen,
413 					   &requestid);
414 		if (ret) {
415 			pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
416 					   ret);
417 			break;
418 		}
419 
420 		if (!recvlen)
421 			break;
422 
423 		/* Ensure recvlen is big enough to read header data */
424 		if (recvlen < ICMSG_HDR) {
425 			pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
426 					   recvlen);
427 			break;
428 		}
429 
430 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
431 				sizeof(struct vmbuspipe_hdr)];
432 
433 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
434 			if (vmbus_prep_negotiate_resp(icmsghdrp,
435 						time_txf_buf, recvlen,
436 						fw_versions, FW_VER_COUNT,
437 						ts_versions, TS_VER_COUNT,
438 						NULL, &ts_srv_version)) {
439 				pr_info("TimeSync IC version %d.%d\n",
440 					ts_srv_version >> 16,
441 					ts_srv_version & 0xFFFF);
442 			}
443 		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
444 			if (ts_srv_version > TS_VERSION_3) {
445 				/* Ensure recvlen is big enough to read ictimesync_ref_data */
446 				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
447 					pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
448 							   recvlen);
449 					break;
450 				}
451 				refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];
452 
453 				adj_guesttime(refdata->parenttime,
454 						refdata->vmreferencetime,
455 						refdata->flags);
456 			} else {
457 				/* Ensure recvlen is big enough to read ictimesync_data */
458 				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
459 					pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
460 							   recvlen);
461 					break;
462 				}
463 				timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];
464 
465 				adj_guesttime(timedatap->parenttime,
466 					      hv_read_reference_counter(),
467 					      timedatap->flags);
468 			}
469 		} else {
470 			icmsghdrp->status = HV_E_FAIL;
471 			pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
472 					   icmsghdrp->icmsgtype);
473 		}
474 
475 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
476 			| ICMSGHDRFLAG_RESPONSE;
477 
478 		vmbus_sendpacket(channel, time_txf_buf,
479 				 recvlen, requestid,
480 				 VM_PKT_DATA_INBAND, 0);
481 	}
482 }
483 
484 /*
485  * Heartbeat functionality.
486  * Every two seconds, Hyper-V send us a heartbeat request message.
487  * we respond to this message, and Hyper-V knows we are alive.
488  */
heartbeat_onchannelcallback(void * context)489 static void heartbeat_onchannelcallback(void *context)
490 {
491 	struct vmbus_channel *channel = context;
492 	u32 recvlen;
493 	u64 requestid;
494 	struct icmsg_hdr *icmsghdrp;
495 	struct heartbeat_msg_data *heartbeat_msg;
496 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
497 
498 	while (1) {
499 
500 		if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
501 				     &recvlen, &requestid)) {
502 			pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
503 			return;
504 		}
505 
506 		if (!recvlen)
507 			break;
508 
509 		/* Ensure recvlen is big enough to read header data */
510 		if (recvlen < ICMSG_HDR) {
511 			pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
512 					   recvlen);
513 			break;
514 		}
515 
516 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
517 				sizeof(struct vmbuspipe_hdr)];
518 
519 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
520 			if (vmbus_prep_negotiate_resp(icmsghdrp,
521 					hbeat_txf_buf, recvlen,
522 					fw_versions, FW_VER_COUNT,
523 					hb_versions, HB_VER_COUNT,
524 					NULL, &hb_srv_version)) {
525 
526 				pr_info("Heartbeat IC version %d.%d\n",
527 					hb_srv_version >> 16,
528 					hb_srv_version & 0xFFFF);
529 			}
530 		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
531 			/*
532 			 * Ensure recvlen is big enough to read seq_num. Reserved area is not
533 			 * included in the check as the host may not fill it up entirely
534 			 */
535 			if (recvlen < ICMSG_HDR + sizeof(u64)) {
536 				pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
537 						   recvlen);
538 				break;
539 			}
540 			heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];
541 
542 			heartbeat_msg->seq_num += 1;
543 		} else {
544 			icmsghdrp->status = HV_E_FAIL;
545 			pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
546 					   icmsghdrp->icmsgtype);
547 		}
548 
549 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
550 			| ICMSGHDRFLAG_RESPONSE;
551 
552 		vmbus_sendpacket(channel, hbeat_txf_buf,
553 				 recvlen, requestid,
554 				 VM_PKT_DATA_INBAND, 0);
555 	}
556 }
557 
558 #define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
559 #define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
560 
util_probe(struct hv_device * dev,const struct hv_vmbus_device_id * dev_id)561 static int util_probe(struct hv_device *dev,
562 			const struct hv_vmbus_device_id *dev_id)
563 {
564 	struct hv_util_service *srv =
565 		(struct hv_util_service *)dev_id->driver_data;
566 	int ret;
567 
568 	srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
569 	if (!srv->recv_buffer)
570 		return -ENOMEM;
571 	srv->channel = dev->channel;
572 	if (srv->util_init) {
573 		ret = srv->util_init(srv);
574 		if (ret) {
575 			ret = -ENODEV;
576 			goto error1;
577 		}
578 	}
579 
580 	/*
581 	 * The set of services managed by the util driver are not performance
582 	 * critical and do not need batched reading. Furthermore, some services
583 	 * such as KVP can only handle one message from the host at a time.
584 	 * Turn off batched reading for all util drivers before we open the
585 	 * channel.
586 	 */
587 	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
588 
589 	hv_set_drvdata(dev, srv);
590 
591 	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
592 			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
593 			 dev->channel);
594 	if (ret)
595 		goto error;
596 
597 	if (srv->util_init_transport) {
598 		ret = srv->util_init_transport();
599 		if (ret) {
600 			vmbus_close(dev->channel);
601 			goto error;
602 		}
603 	}
604 	return 0;
605 
606 error:
607 	if (srv->util_deinit)
608 		srv->util_deinit();
609 error1:
610 	kfree(srv->recv_buffer);
611 	return ret;
612 }
613 
util_remove(struct hv_device * dev)614 static void util_remove(struct hv_device *dev)
615 {
616 	struct hv_util_service *srv = hv_get_drvdata(dev);
617 
618 	if (srv->util_deinit)
619 		srv->util_deinit();
620 	vmbus_close(dev->channel);
621 	kfree(srv->recv_buffer);
622 }
623 
624 /*
625  * When we're in util_suspend(), all the userspace processes have been frozen
626  * (refer to hibernate() -> freeze_processes()). The userspace is thawed only
627  * after the whole resume procedure, including util_resume(), finishes.
628  */
util_suspend(struct hv_device * dev)629 static int util_suspend(struct hv_device *dev)
630 {
631 	struct hv_util_service *srv = hv_get_drvdata(dev);
632 	int ret = 0;
633 
634 	if (srv->util_pre_suspend) {
635 		ret = srv->util_pre_suspend();
636 		if (ret)
637 			return ret;
638 	}
639 
640 	vmbus_close(dev->channel);
641 
642 	return 0;
643 }
644 
util_resume(struct hv_device * dev)645 static int util_resume(struct hv_device *dev)
646 {
647 	struct hv_util_service *srv = hv_get_drvdata(dev);
648 	int ret = 0;
649 
650 	if (srv->util_pre_resume) {
651 		ret = srv->util_pre_resume();
652 		if (ret)
653 			return ret;
654 	}
655 
656 	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
657 			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
658 			 dev->channel);
659 	return ret;
660 }
661 
662 static const struct hv_vmbus_device_id id_table[] = {
663 	/* Shutdown guid */
664 	{ HV_SHUTDOWN_GUID,
665 	  .driver_data = (unsigned long)&util_shutdown
666 	},
667 	/* Time synch guid */
668 	{ HV_TS_GUID,
669 	  .driver_data = (unsigned long)&util_timesynch
670 	},
671 	/* Heartbeat guid */
672 	{ HV_HEART_BEAT_GUID,
673 	  .driver_data = (unsigned long)&util_heartbeat
674 	},
675 	/* KVP guid */
676 	{ HV_KVP_GUID,
677 	  .driver_data = (unsigned long)&util_kvp
678 	},
679 	/* VSS GUID */
680 	{ HV_VSS_GUID,
681 	  .driver_data = (unsigned long)&util_vss
682 	},
683 	/* File copy GUID */
684 	{ HV_FCOPY_GUID,
685 	  .driver_data = (unsigned long)&util_fcopy
686 	},
687 	{ },
688 };
689 
690 MODULE_DEVICE_TABLE(vmbus, id_table);
691 
692 /* The one and only one */
693 static  struct hv_driver util_drv = {
694 	.name = "hv_utils",
695 	.id_table = id_table,
696 	.probe =  util_probe,
697 	.remove =  util_remove,
698 	.suspend = util_suspend,
699 	.resume =  util_resume,
700 	.driver = {
701 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
702 	},
703 };
704 
hv_ptp_enable(struct ptp_clock_info * info,struct ptp_clock_request * request,int on)705 static int hv_ptp_enable(struct ptp_clock_info *info,
706 			 struct ptp_clock_request *request, int on)
707 {
708 	return -EOPNOTSUPP;
709 }
710 
hv_ptp_settime(struct ptp_clock_info * p,const struct timespec64 * ts)711 static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
712 {
713 	return -EOPNOTSUPP;
714 }
715 
hv_ptp_adjfine(struct ptp_clock_info * ptp,long delta)716 static int hv_ptp_adjfine(struct ptp_clock_info *ptp, long delta)
717 {
718 	return -EOPNOTSUPP;
719 }
hv_ptp_adjtime(struct ptp_clock_info * ptp,s64 delta)720 static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
721 {
722 	return -EOPNOTSUPP;
723 }
724 
hv_ptp_gettime(struct ptp_clock_info * info,struct timespec64 * ts)725 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
726 {
727 	return hv_get_adj_host_time(ts);
728 }
729 
730 static struct ptp_clock_info ptp_hyperv_info = {
731 	.name		= "hyperv",
732 	.enable         = hv_ptp_enable,
733 	.adjtime        = hv_ptp_adjtime,
734 	.adjfine        = hv_ptp_adjfine,
735 	.gettime64      = hv_ptp_gettime,
736 	.settime64      = hv_ptp_settime,
737 	.owner		= THIS_MODULE,
738 };
739 
740 static struct ptp_clock *hv_ptp_clock;
741 
hv_timesync_init(struct hv_util_service * srv)742 static int hv_timesync_init(struct hv_util_service *srv)
743 {
744 	spin_lock_init(&host_ts.lock);
745 
746 	INIT_WORK(&adj_time_work, hv_set_host_time);
747 
748 	/*
749 	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
750 	 * disabled but the driver is still useful without the PTP device
751 	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
752 	 */
753 	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
754 	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
755 		pr_err("cannot register PTP clock: %d\n",
756 		       PTR_ERR_OR_ZERO(hv_ptp_clock));
757 		hv_ptp_clock = NULL;
758 	}
759 
760 	return 0;
761 }
762 
hv_timesync_cancel_work(void)763 static void hv_timesync_cancel_work(void)
764 {
765 	cancel_work_sync(&adj_time_work);
766 }
767 
hv_timesync_pre_suspend(void)768 static int hv_timesync_pre_suspend(void)
769 {
770 	hv_timesync_cancel_work();
771 	return 0;
772 }
773 
hv_timesync_deinit(void)774 static void hv_timesync_deinit(void)
775 {
776 	if (hv_ptp_clock)
777 		ptp_clock_unregister(hv_ptp_clock);
778 
779 	hv_timesync_cancel_work();
780 }
781 
init_hyperv_utils(void)782 static int __init init_hyperv_utils(void)
783 {
784 	pr_info("Registering HyperV Utility Driver\n");
785 
786 	return vmbus_driver_register(&util_drv);
787 }
788 
exit_hyperv_utils(void)789 static void exit_hyperv_utils(void)
790 {
791 	pr_info("De-Registered HyperV Utility Driver\n");
792 
793 	vmbus_driver_unregister(&util_drv);
794 }
795 
796 module_init(init_hyperv_utils);
797 module_exit(exit_hyperv_utils);
798 
799 MODULE_DESCRIPTION("Hyper-V Utilities");
800 MODULE_LICENSE("GPL");
801