xref: /openbmc/linux/drivers/hv/hv_util.c (revision 9b93eb47)
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 #include <linux/clockchips.h>
31 #include <linux/ptp_clock_kernel.h>
32 #include <asm/mshyperv.h>
33 
34 #include "hyperv_vmbus.h"
35 
36 #define SD_MAJOR	3
37 #define SD_MINOR	0
38 #define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)
39 
40 #define SD_MAJOR_1	1
41 #define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)
42 
43 #define TS_MAJOR	4
44 #define TS_MINOR	0
45 #define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)
46 
47 #define TS_MAJOR_1	1
48 #define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)
49 
50 #define TS_MAJOR_3	3
51 #define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)
52 
53 #define HB_MAJOR	3
54 #define HB_MINOR	0
55 #define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)
56 
57 #define HB_MAJOR_1	1
58 #define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)
59 
60 static int sd_srv_version;
61 static int ts_srv_version;
62 static int hb_srv_version;
63 
64 #define SD_VER_COUNT 2
65 static const int sd_versions[] = {
66 	SD_VERSION,
67 	SD_VERSION_1
68 };
69 
70 #define TS_VER_COUNT 3
71 static const int ts_versions[] = {
72 	TS_VERSION,
73 	TS_VERSION_3,
74 	TS_VERSION_1
75 };
76 
77 #define HB_VER_COUNT 2
78 static const int hb_versions[] = {
79 	HB_VERSION,
80 	HB_VERSION_1
81 };
82 
83 #define FW_VER_COUNT 2
84 static const int fw_versions[] = {
85 	UTIL_FW_VERSION,
86 	UTIL_WS2K8_FW_VERSION
87 };
88 
89 static void shutdown_onchannelcallback(void *context);
90 static struct hv_util_service util_shutdown = {
91 	.util_cb = shutdown_onchannelcallback,
92 };
93 
94 static int hv_timesync_init(struct hv_util_service *srv);
95 static void hv_timesync_deinit(void);
96 
97 static void timesync_onchannelcallback(void *context);
98 static struct hv_util_service util_timesynch = {
99 	.util_cb = timesync_onchannelcallback,
100 	.util_init = hv_timesync_init,
101 	.util_deinit = hv_timesync_deinit,
102 };
103 
104 static void heartbeat_onchannelcallback(void *context);
105 static struct hv_util_service util_heartbeat = {
106 	.util_cb = heartbeat_onchannelcallback,
107 };
108 
109 static struct hv_util_service util_kvp = {
110 	.util_cb = hv_kvp_onchannelcallback,
111 	.util_init = hv_kvp_init,
112 	.util_deinit = hv_kvp_deinit,
113 };
114 
115 static struct hv_util_service util_vss = {
116 	.util_cb = hv_vss_onchannelcallback,
117 	.util_init = hv_vss_init,
118 	.util_deinit = hv_vss_deinit,
119 };
120 
121 static struct hv_util_service util_fcopy = {
122 	.util_cb = hv_fcopy_onchannelcallback,
123 	.util_init = hv_fcopy_init,
124 	.util_deinit = hv_fcopy_deinit,
125 };
126 
127 static void perform_shutdown(struct work_struct *dummy)
128 {
129 	orderly_poweroff(true);
130 }
131 
132 /*
133  * Perform the shutdown operation in a thread context.
134  */
135 static DECLARE_WORK(shutdown_work, perform_shutdown);
136 
137 static void shutdown_onchannelcallback(void *context)
138 {
139 	struct vmbus_channel *channel = context;
140 	u32 recvlen;
141 	u64 requestid;
142 	bool execute_shutdown = false;
143 	u8  *shut_txf_buf = util_shutdown.recv_buffer;
144 
145 	struct shutdown_msg_data *shutdown_msg;
146 
147 	struct icmsg_hdr *icmsghdrp;
148 
149 	vmbus_recvpacket(channel, shut_txf_buf,
150 			 PAGE_SIZE, &recvlen, &requestid);
151 
152 	if (recvlen > 0) {
153 		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
154 			sizeof(struct vmbuspipe_hdr)];
155 
156 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
157 			if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
158 					fw_versions, FW_VER_COUNT,
159 					sd_versions, SD_VER_COUNT,
160 					NULL, &sd_srv_version)) {
161 				pr_info("Shutdown IC version %d.%d\n",
162 					sd_srv_version >> 16,
163 					sd_srv_version & 0xFFFF);
164 			}
165 		} else {
166 			shutdown_msg =
167 				(struct shutdown_msg_data *)&shut_txf_buf[
168 					sizeof(struct vmbuspipe_hdr) +
169 					sizeof(struct icmsg_hdr)];
170 
171 			switch (shutdown_msg->flags) {
172 			case 0:
173 			case 1:
174 				icmsghdrp->status = HV_S_OK;
175 				execute_shutdown = true;
176 
177 				pr_info("Shutdown request received -"
178 					    " graceful shutdown initiated\n");
179 				break;
180 			default:
181 				icmsghdrp->status = HV_E_FAIL;
182 				execute_shutdown = false;
183 
184 				pr_info("Shutdown request received -"
185 					    " Invalid request\n");
186 				break;
187 			}
188 		}
189 
190 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
191 			| ICMSGHDRFLAG_RESPONSE;
192 
193 		vmbus_sendpacket(channel, shut_txf_buf,
194 				       recvlen, requestid,
195 				       VM_PKT_DATA_INBAND, 0);
196 	}
197 
198 	if (execute_shutdown == true)
199 		schedule_work(&shutdown_work);
200 }
201 
202 /*
203  * Set the host time in a process context.
204  */
205 static struct work_struct adj_time_work;
206 
207 /*
208  * The last time sample, received from the host. PTP device responds to
209  * requests by using this data and the current partition-wide time reference
210  * count.
211  */
212 static struct {
213 	u64				host_time;
214 	u64				ref_time;
215 	spinlock_t			lock;
216 } host_ts;
217 
218 static struct timespec64 hv_get_adj_host_time(void)
219 {
220 	struct timespec64 ts;
221 	u64 newtime, reftime;
222 	unsigned long flags;
223 
224 	spin_lock_irqsave(&host_ts.lock, flags);
225 	reftime = hyperv_cs->read(hyperv_cs);
226 	newtime = host_ts.host_time + (reftime - host_ts.ref_time);
227 	ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
228 	spin_unlock_irqrestore(&host_ts.lock, flags);
229 
230 	return ts;
231 }
232 
233 static void hv_set_host_time(struct work_struct *work)
234 {
235 	struct timespec64 ts = hv_get_adj_host_time();
236 
237 	do_settimeofday64(&ts);
238 }
239 
240 /*
241  * Synchronize time with host after reboot, restore, etc.
242  *
243  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
244  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
245  * message after the timesync channel is opened. Since the hv_utils module is
246  * loaded after hv_vmbus, the first message is usually missed. This bit is
247  * considered a hard request to discipline the clock.
248  *
249  * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
250  * typically used as a hint to the guest. The guest is under no obligation
251  * to discipline the clock.
252  */
253 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
254 {
255 	unsigned long flags;
256 	u64 cur_reftime;
257 
258 	/*
259 	 * Save the adjusted time sample from the host and the snapshot
260 	 * of the current system time.
261 	 */
262 	spin_lock_irqsave(&host_ts.lock, flags);
263 
264 	cur_reftime = hyperv_cs->read(hyperv_cs);
265 	host_ts.host_time = hosttime;
266 	host_ts.ref_time = cur_reftime;
267 
268 	/*
269 	 * TimeSync v4 messages contain reference time (guest's Hyper-V
270 	 * clocksource read when the time sample was generated), we can
271 	 * improve the precision by adding the delta between now and the
272 	 * time of generation. For older protocols we set
273 	 * reftime == cur_reftime on call.
274 	 */
275 	host_ts.host_time += (cur_reftime - reftime);
276 
277 	spin_unlock_irqrestore(&host_ts.lock, flags);
278 
279 	/* Schedule work to do do_settimeofday64() */
280 	if (adj_flags & ICTIMESYNCFLAG_SYNC)
281 		schedule_work(&adj_time_work);
282 }
283 
284 /*
285  * Time Sync Channel message handler.
286  */
287 static void timesync_onchannelcallback(void *context)
288 {
289 	struct vmbus_channel *channel = context;
290 	u32 recvlen;
291 	u64 requestid;
292 	struct icmsg_hdr *icmsghdrp;
293 	struct ictimesync_data *timedatap;
294 	struct ictimesync_ref_data *refdata;
295 	u8 *time_txf_buf = util_timesynch.recv_buffer;
296 
297 	vmbus_recvpacket(channel, time_txf_buf,
298 			 PAGE_SIZE, &recvlen, &requestid);
299 
300 	if (recvlen > 0) {
301 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
302 				sizeof(struct vmbuspipe_hdr)];
303 
304 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
305 			if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
306 						fw_versions, FW_VER_COUNT,
307 						ts_versions, TS_VER_COUNT,
308 						NULL, &ts_srv_version)) {
309 				pr_info("TimeSync IC version %d.%d\n",
310 					ts_srv_version >> 16,
311 					ts_srv_version & 0xFFFF);
312 			}
313 		} else {
314 			if (ts_srv_version > TS_VERSION_3) {
315 				refdata = (struct ictimesync_ref_data *)
316 					&time_txf_buf[
317 					sizeof(struct vmbuspipe_hdr) +
318 					sizeof(struct icmsg_hdr)];
319 
320 				adj_guesttime(refdata->parenttime,
321 						refdata->vmreferencetime,
322 						refdata->flags);
323 			} else {
324 				timedatap = (struct ictimesync_data *)
325 					&time_txf_buf[
326 					sizeof(struct vmbuspipe_hdr) +
327 					sizeof(struct icmsg_hdr)];
328 				adj_guesttime(timedatap->parenttime,
329 					      hyperv_cs->read(hyperv_cs),
330 					      timedatap->flags);
331 			}
332 		}
333 
334 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
335 			| ICMSGHDRFLAG_RESPONSE;
336 
337 		vmbus_sendpacket(channel, time_txf_buf,
338 				recvlen, requestid,
339 				VM_PKT_DATA_INBAND, 0);
340 	}
341 }
342 
343 /*
344  * Heartbeat functionality.
345  * Every two seconds, Hyper-V send us a heartbeat request message.
346  * we respond to this message, and Hyper-V knows we are alive.
347  */
348 static void heartbeat_onchannelcallback(void *context)
349 {
350 	struct vmbus_channel *channel = context;
351 	u32 recvlen;
352 	u64 requestid;
353 	struct icmsg_hdr *icmsghdrp;
354 	struct heartbeat_msg_data *heartbeat_msg;
355 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
356 
357 	while (1) {
358 
359 		vmbus_recvpacket(channel, hbeat_txf_buf,
360 				 PAGE_SIZE, &recvlen, &requestid);
361 
362 		if (!recvlen)
363 			break;
364 
365 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
366 				sizeof(struct vmbuspipe_hdr)];
367 
368 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
369 			if (vmbus_prep_negotiate_resp(icmsghdrp,
370 					hbeat_txf_buf,
371 					fw_versions, FW_VER_COUNT,
372 					hb_versions, HB_VER_COUNT,
373 					NULL, &hb_srv_version)) {
374 
375 				pr_info("Heartbeat IC version %d.%d\n",
376 					hb_srv_version >> 16,
377 					hb_srv_version & 0xFFFF);
378 			}
379 		} else {
380 			heartbeat_msg =
381 				(struct heartbeat_msg_data *)&hbeat_txf_buf[
382 					sizeof(struct vmbuspipe_hdr) +
383 					sizeof(struct icmsg_hdr)];
384 
385 			heartbeat_msg->seq_num += 1;
386 		}
387 
388 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
389 			| ICMSGHDRFLAG_RESPONSE;
390 
391 		vmbus_sendpacket(channel, hbeat_txf_buf,
392 				       recvlen, requestid,
393 				       VM_PKT_DATA_INBAND, 0);
394 	}
395 }
396 
397 static int util_probe(struct hv_device *dev,
398 			const struct hv_vmbus_device_id *dev_id)
399 {
400 	struct hv_util_service *srv =
401 		(struct hv_util_service *)dev_id->driver_data;
402 	int ret;
403 
404 	srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
405 	if (!srv->recv_buffer)
406 		return -ENOMEM;
407 	srv->channel = dev->channel;
408 	if (srv->util_init) {
409 		ret = srv->util_init(srv);
410 		if (ret) {
411 			ret = -ENODEV;
412 			goto error1;
413 		}
414 	}
415 
416 	/*
417 	 * The set of services managed by the util driver are not performance
418 	 * critical and do not need batched reading. Furthermore, some services
419 	 * such as KVP can only handle one message from the host at a time.
420 	 * Turn off batched reading for all util drivers before we open the
421 	 * channel.
422 	 */
423 	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
424 
425 	hv_set_drvdata(dev, srv);
426 
427 	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
428 			srv->util_cb, dev->channel);
429 	if (ret)
430 		goto error;
431 
432 	return 0;
433 
434 error:
435 	if (srv->util_deinit)
436 		srv->util_deinit();
437 error1:
438 	kfree(srv->recv_buffer);
439 	return ret;
440 }
441 
442 static int util_remove(struct hv_device *dev)
443 {
444 	struct hv_util_service *srv = hv_get_drvdata(dev);
445 
446 	if (srv->util_deinit)
447 		srv->util_deinit();
448 	vmbus_close(dev->channel);
449 	kfree(srv->recv_buffer);
450 
451 	return 0;
452 }
453 
454 static const struct hv_vmbus_device_id id_table[] = {
455 	/* Shutdown guid */
456 	{ HV_SHUTDOWN_GUID,
457 	  .driver_data = (unsigned long)&util_shutdown
458 	},
459 	/* Time synch guid */
460 	{ HV_TS_GUID,
461 	  .driver_data = (unsigned long)&util_timesynch
462 	},
463 	/* Heartbeat guid */
464 	{ HV_HEART_BEAT_GUID,
465 	  .driver_data = (unsigned long)&util_heartbeat
466 	},
467 	/* KVP guid */
468 	{ HV_KVP_GUID,
469 	  .driver_data = (unsigned long)&util_kvp
470 	},
471 	/* VSS GUID */
472 	{ HV_VSS_GUID,
473 	  .driver_data = (unsigned long)&util_vss
474 	},
475 	/* File copy GUID */
476 	{ HV_FCOPY_GUID,
477 	  .driver_data = (unsigned long)&util_fcopy
478 	},
479 	{ },
480 };
481 
482 MODULE_DEVICE_TABLE(vmbus, id_table);
483 
484 /* The one and only one */
485 static  struct hv_driver util_drv = {
486 	.name = "hv_utils",
487 	.id_table = id_table,
488 	.probe =  util_probe,
489 	.remove =  util_remove,
490 	.driver = {
491 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
492 	},
493 };
494 
495 static int hv_ptp_enable(struct ptp_clock_info *info,
496 			 struct ptp_clock_request *request, int on)
497 {
498 	return -EOPNOTSUPP;
499 }
500 
501 static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
502 {
503 	return -EOPNOTSUPP;
504 }
505 
506 static int hv_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
507 {
508 	return -EOPNOTSUPP;
509 }
510 static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
511 {
512 	return -EOPNOTSUPP;
513 }
514 
515 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
516 {
517 	*ts = hv_get_adj_host_time();
518 
519 	return 0;
520 }
521 
522 static struct ptp_clock_info ptp_hyperv_info = {
523 	.name		= "hyperv",
524 	.enable         = hv_ptp_enable,
525 	.adjtime        = hv_ptp_adjtime,
526 	.adjfreq        = hv_ptp_adjfreq,
527 	.gettime64      = hv_ptp_gettime,
528 	.settime64      = hv_ptp_settime,
529 	.owner		= THIS_MODULE,
530 };
531 
532 static struct ptp_clock *hv_ptp_clock;
533 
534 static int hv_timesync_init(struct hv_util_service *srv)
535 {
536 	/* TimeSync requires Hyper-V clocksource. */
537 	if (!hyperv_cs)
538 		return -ENODEV;
539 
540 	spin_lock_init(&host_ts.lock);
541 
542 	INIT_WORK(&adj_time_work, hv_set_host_time);
543 
544 	/*
545 	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
546 	 * disabled but the driver is still useful without the PTP device
547 	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
548 	 */
549 	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
550 	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
551 		pr_err("cannot register PTP clock: %ld\n",
552 		       PTR_ERR(hv_ptp_clock));
553 		hv_ptp_clock = NULL;
554 	}
555 
556 	return 0;
557 }
558 
559 static void hv_timesync_deinit(void)
560 {
561 	if (hv_ptp_clock)
562 		ptp_clock_unregister(hv_ptp_clock);
563 	cancel_work_sync(&adj_time_work);
564 }
565 
566 static int __init init_hyperv_utils(void)
567 {
568 	pr_info("Registering HyperV Utility Driver\n");
569 
570 	return vmbus_driver_register(&util_drv);
571 }
572 
573 static void exit_hyperv_utils(void)
574 {
575 	pr_info("De-Registered HyperV Utility Driver\n");
576 
577 	vmbus_driver_unregister(&util_drv);
578 }
579 
580 module_init(init_hyperv_utils);
581 module_exit(exit_hyperv_utils);
582 
583 MODULE_DESCRIPTION("Hyper-V Utilities");
584 MODULE_LICENSE("GPL");
585