drivers/hv/hv_util.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2010, Microsoft Corporation.
   4  *
   5  * Authors:
   6  *   Haiyang Zhang <[email protected]>
   7  *   Hank Janssen  <[email protected]>
   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
  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
 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_pre_suspend = hv_kvp_pre_suspend,
 145         .util_pre_resume = hv_kvp_pre_resume,
 146         .util_deinit = hv_kvp_deinit,
 147 };
 148
 149 static struct hv_util_service util_vss = {
 150         .util_cb = hv_vss_onchannelcallback,
 151         .util_init = hv_vss_init,
 152         .util_pre_suspend = hv_vss_pre_suspend,
 153         .util_pre_resume = hv_vss_pre_resume,
 154         .util_deinit = hv_vss_deinit,
 155 };
 156
 157 static void perform_shutdown(struct work_struct *dummy)
 158 {
 159         orderly_poweroff(true);
 160 }
 161
 162 static void perform_restart(struct work_struct *dummy)
 163 {
 164         orderly_reboot();
 165 }
 166
 167 /*
 168  * Perform the shutdown operation in a thread context.
 169  */
 170 static DECLARE_WORK(shutdown_work, perform_shutdown);
 171
 172 /*
 173  * Perform the restart operation in a thread context.
 174  */
 175 static DECLARE_WORK(restart_work, perform_restart);
 176
 177 static void shutdown_onchannelcallback(void *context)
 178 {
 179         struct vmbus_channel *channel = context;
 180         struct work_struct *work = NULL;
 181         u32 recvlen;
 182         u64 requestid;
 183         u8  *shut_txf_buf = util_shutdown.recv_buffer;
 184
 185         struct shutdown_msg_data *shutdown_msg;
 186
 187         struct icmsg_hdr *icmsghdrp;
 188
 189         if (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
 190                 pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
 191                 return;
 192         }
 193
 194         if (!recvlen)
 195                 return;
 196
 197         /* Ensure recvlen is big enough to read header data */
 198         if (recvlen < ICMSG_HDR) {
 199                 pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
 200                                    recvlen);
 201                 return;
 202         }
 203
 204         icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[sizeof(struct vmbuspipe_hdr)];
 205
 206         if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 207                 if (vmbus_prep_negotiate_resp(icmsghdrp,
 208                                 shut_txf_buf, recvlen,
 209                                 fw_versions, FW_VER_COUNT,
 210                                 sd_versions, SD_VER_COUNT,
 211                                 NULL, &sd_srv_version)) {
 212                         pr_info("Shutdown IC version %d.%d\n",
 213                                 sd_srv_version >> 16,
 214                                 sd_srv_version & 0xFFFF);
 215                 }
 216         } else if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
 217                 /* Ensure recvlen is big enough to contain shutdown_msg_data struct */
 218                 if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
 219                         pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
 220                                            recvlen);
 221                         return;
 222                 }
 223
 224                 shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];
 225
 226                 /*
 227                  * shutdown_msg->flags can be 0(shut down), 2(reboot),
 228                  * or 4(hibernate). It may bitwise-OR 1, which means
 229                  * performing the request by force. Linux always tries
 230                  * to perform the request by force.
 231                  */
 232                 switch (shutdown_msg->flags) {
 233                 case 0:
 234                 case 1:
 235                         icmsghdrp->status = HV_S_OK;
 236                         work = &shutdown_work;
 237                         pr_info("Shutdown request received - graceful shutdown initiated\n");
 238                         break;
 239                 case 2:
 240                 case 3:
 241                         icmsghdrp->status = HV_S_OK;
 242                         work = &restart_work;
 243                         pr_info("Restart request received - graceful restart initiated\n");
 244                         break;
 245                 case 4:
 246                 case 5:
 247                         pr_info("Hibernation request received\n");
 248                         icmsghdrp->status = hibernation_supported ?
 249                                 HV_S_OK : HV_E_FAIL;
 250                         if (hibernation_supported)
 251                                 work = &hibernate_context.work;
 252                         break;
 253                 default:
 254                         icmsghdrp->status = HV_E_FAIL;
 255                         pr_info("Shutdown request received - Invalid request\n");
 256                         break;
 257                 }
 258         } else {
 259                 icmsghdrp->status = HV_E_FAIL;
 260                 pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
 261                                    icmsghdrp->icmsgtype);
 262         }
 263
 264         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 265                 | ICMSGHDRFLAG_RESPONSE;
 266
 267         vmbus_sendpacket(channel, shut_txf_buf,
 268                          recvlen, requestid,
 269                          VM_PKT_DATA_INBAND, 0);
 270
 271         if (work)
 272                 schedule_work(work);
 273 }
 274
 275 /*
 276  * Set the host time in a process context.
 277  */
 278 static struct work_struct adj_time_work;
 279
 280 /*
 281  * The last time sample, received from the host. PTP device responds to
 282  * requests by using this data and the current partition-wide time reference
 283  * count.
 284  */
 285 static struct {
 286         u64                             host_time;
 287         u64                             ref_time;
 288         spinlock_t                      lock;
 289 } host_ts;
 290
 291 static bool timesync_implicit;
 292
 293 module_param(timesync_implicit, bool, 0644);
 294 MODULE_PARM_DESC(timesync_implicit, "If set treat SAMPLE as SYNC when clock is behind");
 295
 296 static inline u64 reftime_to_ns(u64 reftime)
 297 {
 298         return (reftime - WLTIMEDELTA) * 100;
 299 }
 300
 301 /*
 302  * Hard coded threshold for host timesync delay: 600 seconds
 303  */
 304 static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;
 305
 306 static int hv_get_adj_host_time(struct timespec64 *ts)
 307 {
 308         u64 newtime, reftime, timediff_adj;
 309         unsigned long flags;
 310         int ret = 0;
 311
 312         spin_lock_irqsave(&host_ts.lock, flags);
 313         reftime = hv_read_reference_counter();
 314
 315         /*
 316          * We need to let the caller know that last update from host
 317          * is older than the max allowable threshold. clock_gettime()
 318          * and PTP ioctl do not have a documented error that we could
 319          * return for this specific case. Use ESTALE to report this.
 320          */
 321         timediff_adj = reftime - host_ts.ref_time;
 322         if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
 323                 pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
 324                              (timediff_adj * 100));
 325                 ret = -ESTALE;
 326         }
 327
 328         newtime = host_ts.host_time + timediff_adj;
 329         *ts = ns_to_timespec64(reftime_to_ns(newtime));
 330         spin_unlock_irqrestore(&host_ts.lock, flags);
 331
 332         return ret;
 333 }
 334
 335 static void hv_set_host_time(struct work_struct *work)
 336 {
 337
 338         struct timespec64 ts;
 339
 340         if (!hv_get_adj_host_time(&ts))
 341                 do_settimeofday64(&ts);
 342 }
 343
 344 /*
 345  * Due to a bug on Hyper-V hosts, the sync flag may not always be sent on resume.
 346  * Force a sync if the guest is behind.
 347  */
 348 static inline bool hv_implicit_sync(u64 host_time)
 349 {
 350         struct timespec64 new_ts;
 351         struct timespec64 threshold_ts;
 352
 353         new_ts = ns_to_timespec64(reftime_to_ns(host_time));
 354         ktime_get_real_ts64(&threshold_ts);
 355
 356         threshold_ts.tv_sec += 5;
 357
 358         /*
 359          * If guest behind the host by 5 or more seconds.
 360          */
 361         if (timespec64_compare(&new_ts, &threshold_ts) >= 0)
 362                 return true;
 363
 364         return false;
 365 }
 366
 367 /*
 368  * Synchronize time with host after reboot, restore, etc.
 369  *
 370  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
 371  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
 372  * message after the timesync channel is opened. Since the hv_utils module is
 373  * loaded after hv_vmbus, the first message is usually missed. This bit is
 374  * considered a hard request to discipline the clock.
 375  *
 376  * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
 377  * typically used as a hint to the guest. The guest is under no obligation
 378  * to discipline the clock.
 379  */
 380 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
 381 {
 382         unsigned long flags;
 383         u64 cur_reftime;
 384
 385         /*
 386          * Save the adjusted time sample from the host and the snapshot
 387          * of the current system time.
 388          */
 389         spin_lock_irqsave(&host_ts.lock, flags);
 390
 391         cur_reftime = hv_read_reference_counter();
 392         host_ts.host_time = hosttime;
 393         host_ts.ref_time = cur_reftime;
 394
 395         /*
 396          * TimeSync v4 messages contain reference time (guest's Hyper-V
 397          * clocksource read when the time sample was generated), we can
 398          * improve the precision by adding the delta between now and the
 399          * time of generation. For older protocols we set
 400          * reftime == cur_reftime on call.
 401          */
 402         host_ts.host_time += (cur_reftime - reftime);
 403
 404         spin_unlock_irqrestore(&host_ts.lock, flags);
 405
 406         /* Schedule work to do do_settimeofday64() */
 407         if ((adj_flags & ICTIMESYNCFLAG_SYNC) ||
 408             (timesync_implicit && hv_implicit_sync(host_ts.host_time)))
 409                 schedule_work(&adj_time_work);
 410 }
 411
 412 /*
 413  * Time Sync Channel message handler.
 414  */
 415 static void timesync_onchannelcallback(void *context)
 416 {
 417         struct vmbus_channel *channel = context;
 418         u32 recvlen;
 419         u64 requestid;
 420         struct icmsg_hdr *icmsghdrp;
 421         struct ictimesync_data *timedatap;
 422         struct ictimesync_ref_data *refdata;
 423         u8 *time_txf_buf = util_timesynch.recv_buffer;
 424
 425         /*
 426          * Drain the ring buffer and use the last packet to update
 427          * host_ts
 428          */
 429         while (1) {
 430                 int ret = vmbus_recvpacket(channel, time_txf_buf,
 431                                            HV_HYP_PAGE_SIZE, &recvlen,
 432                                            &requestid);
 433                 if (ret) {
 434                         pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
 435                                            ret);
 436                         break;
 437                 }
 438
 439                 if (!recvlen)
 440                         break;
 441
 442                 /* Ensure recvlen is big enough to read header data */
 443                 if (recvlen < ICMSG_HDR) {
 444                         pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
 445                                            recvlen);
 446                         break;
 447                 }
 448
 449                 icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
 450                                 sizeof(struct vmbuspipe_hdr)];
 451
 452                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 453                         if (vmbus_prep_negotiate_resp(icmsghdrp,
 454                                                 time_txf_buf, recvlen,
 455                                                 fw_versions, FW_VER_COUNT,
 456                                                 ts_versions, TS_VER_COUNT,
 457                                                 NULL, &ts_srv_version)) {
 458                                 pr_info("TimeSync IC version %d.%d\n",
 459                                         ts_srv_version >> 16,
 460                                         ts_srv_version & 0xFFFF);
 461                         }
 462                 } else if (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
 463                         if (ts_srv_version > TS_VERSION_3) {
 464                                 /* Ensure recvlen is big enough to read ictimesync_ref_data */
 465                                 if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
 466                                         pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
 467                                                            recvlen);
 468                                         break;
 469                                 }
 470                                 refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];
 471
 472                                 adj_guesttime(refdata->parenttime,
 473                                                 refdata->vmreferencetime,
 474                                                 refdata->flags);
 475                         } else {
 476                                 /* Ensure recvlen is big enough to read ictimesync_data */
 477                                 if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
 478                                         pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
 479                                                            recvlen);
 480                                         break;
 481                                 }
 482                                 timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];
 483
 484                                 adj_guesttime(timedatap->parenttime,
 485                                               hv_read_reference_counter(),
 486                                               timedatap->flags);
 487                         }
 488                 } else {
 489                         icmsghdrp->status = HV_E_FAIL;
 490                         pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
 491                                            icmsghdrp->icmsgtype);
 492                 }
 493
 494                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 495                         | ICMSGHDRFLAG_RESPONSE;
 496
 497                 vmbus_sendpacket(channel, time_txf_buf,
 498                                  recvlen, requestid,
 499                                  VM_PKT_DATA_INBAND, 0);
 500         }
 501 }
 502
 503 /*
 504  * Heartbeat functionality.
 505  * Every two seconds, Hyper-V send us a heartbeat request message.
 506  * we respond to this message, and Hyper-V knows we are alive.
 507  */
 508 static void heartbeat_onchannelcallback(void *context)
 509 {
 510         struct vmbus_channel *channel = context;
 511         u32 recvlen;
 512         u64 requestid;
 513         struct icmsg_hdr *icmsghdrp;
 514         struct heartbeat_msg_data *heartbeat_msg;
 515         u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
 516
 517         while (1) {
 518
 519                 if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
 520                                      &recvlen, &requestid)) {
 521                         pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
 522                         return;
 523                 }
 524
 525                 if (!recvlen)
 526                         break;
 527
 528                 /* Ensure recvlen is big enough to read header data */
 529                 if (recvlen < ICMSG_HDR) {
 530                         pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
 531                                            recvlen);
 532                         break;
 533                 }
 534
 535                 icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
 536                                 sizeof(struct vmbuspipe_hdr)];
 537
 538                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 539                         if (vmbus_prep_negotiate_resp(icmsghdrp,
 540                                         hbeat_txf_buf, recvlen,
 541                                         fw_versions, FW_VER_COUNT,
 542                                         hb_versions, HB_VER_COUNT,
 543                                         NULL, &hb_srv_version)) {
 544
 545                                 pr_info("Heartbeat IC version %d.%d\n",
 546                                         hb_srv_version >> 16,
 547                                         hb_srv_version & 0xFFFF);
 548                         }
 549                 } else if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
 550                         /*
 551                          * Ensure recvlen is big enough to read seq_num. Reserved area is not
 552                          * included in the check as the host may not fill it up entirely
 553                          */
 554                         if (recvlen < ICMSG_HDR + sizeof(u64)) {
 555                                 pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
 556                                                    recvlen);
 557                                 break;
 558                         }
 559                         heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];
 560
 561                         heartbeat_msg->seq_num += 1;
 562                 } else {
 563                         icmsghdrp->status = HV_E_FAIL;
 564                         pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
 565                                            icmsghdrp->icmsgtype);
 566                 }
 567
 568                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 569                         | ICMSGHDRFLAG_RESPONSE;
 570
 571                 vmbus_sendpacket(channel, hbeat_txf_buf,
 572                                  recvlen, requestid,
 573                                  VM_PKT_DATA_INBAND, 0);
 574         }
 575 }
 576
 577 #define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
 578 #define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
 579
 580 static int util_probe(struct hv_device *dev,
 581                         const struct hv_vmbus_device_id *dev_id)
 582 {
 583         struct hv_util_service *srv =
 584                 (struct hv_util_service *)dev_id->driver_data;
 585         int ret;
 586
 587         srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
 588         if (!srv->recv_buffer)
 589                 return -ENOMEM;
 590         srv->channel = dev->channel;
 591         if (srv->util_init) {
 592                 ret = srv->util_init(srv);
 593                 if (ret) {
 594                         ret = -ENODEV;
 595                         goto error1;
 596                 }
 597         }
 598
 599         /*
 600          * The set of services managed by the util driver are not performance
 601          * critical and do not need batched reading. Furthermore, some services
 602          * such as KVP can only handle one message from the host at a time.
 603          * Turn off batched reading for all util drivers before we open the
 604          * channel.
 605          */
 606         set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
 607
 608         hv_set_drvdata(dev, srv);
 609
 610         ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
 611                          HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
 612                          dev->channel);
 613         if (ret)
 614                 goto error;
 615
 616         return 0;
 617
 618 error:
 619         if (srv->util_deinit)
 620                 srv->util_deinit();
 621 error1:
 622         kfree(srv->recv_buffer);
 623         return ret;
 624 }
 625
 626 static void util_remove(struct hv_device *dev)
 627 {
 628         struct hv_util_service *srv = hv_get_drvdata(dev);
 629
 630         if (srv->util_deinit)
 631                 srv->util_deinit();
 632         vmbus_close(dev->channel);
 633         kfree(srv->recv_buffer);
 634 }
 635
 636 /*
 637  * When we're in util_suspend(), all the userspace processes have been frozen
 638  * (refer to hibernate() -> freeze_processes()). The userspace is thawed only
 639  * after the whole resume procedure, including util_resume(), finishes.
 640  */
 641 static int util_suspend(struct hv_device *dev)
 642 {
 643         struct hv_util_service *srv = hv_get_drvdata(dev);
 644         int ret = 0;
 645
 646         if (srv->util_pre_suspend) {
 647                 ret = srv->util_pre_suspend();
 648                 if (ret)
 649                         return ret;
 650         }
 651
 652         vmbus_close(dev->channel);
 653
 654         return 0;
 655 }
 656
 657 static int util_resume(struct hv_device *dev)
 658 {
 659         struct hv_util_service *srv = hv_get_drvdata(dev);
 660         int ret = 0;
 661
 662         if (srv->util_pre_resume) {
 663                 ret = srv->util_pre_resume();
 664                 if (ret)
 665                         return ret;
 666         }
 667
 668         ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
 669                          HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
 670                          dev->channel);
 671         return ret;
 672 }
 673
 674 static const struct hv_vmbus_device_id id_table[] = {
 675         /* Shutdown guid */
 676         { HV_SHUTDOWN_GUID,
 677           .driver_data = (unsigned long)&util_shutdown
 678         },
 679         /* Time synch guid */
 680         { HV_TS_GUID,
 681           .driver_data = (unsigned long)&util_timesynch
 682         },
 683         /* Heartbeat guid */
 684         { HV_HEART_BEAT_GUID,
 685           .driver_data = (unsigned long)&util_heartbeat
 686         },
 687         /* KVP guid */
 688         { HV_KVP_GUID,
 689           .driver_data = (unsigned long)&util_kvp
 690         },
 691         /* VSS GUID */
 692         { HV_VSS_GUID,
 693           .driver_data = (unsigned long)&util_vss
 694         },
 695         { },
 696 };
 697
 698 MODULE_DEVICE_TABLE(vmbus, id_table);
 699
 700 /* The one and only one */
 701 static  struct hv_driver util_drv = {
 702         .name = "hv_utils",
 703         .id_table = id_table,
 704         .probe =  util_probe,
 705         .remove =  util_remove,
 706         .suspend = util_suspend,
 707         .resume =  util_resume,
 708         .driver = {
 709                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 710         },
 711 };
 712
 713 static int hv_ptp_enable(struct ptp_clock_info *info,
 714                          struct ptp_clock_request *request, int on)
 715 {
 716         return -EOPNOTSUPP;
 717 }
 718
 719 static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
 720 {
 721         return -EOPNOTSUPP;
 722 }
 723
 724 static int hv_ptp_adjfine(struct ptp_clock_info *ptp, long delta)
 725 {
 726         return -EOPNOTSUPP;
 727 }
 728 static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 729 {
 730         return -EOPNOTSUPP;
 731 }
 732
 733 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
 734 {
 735         return hv_get_adj_host_time(ts);
 736 }
 737
 738 static struct ptp_clock_info ptp_hyperv_info = {
 739         .name           = "hyperv",
 740         .enable         = hv_ptp_enable,
 741         .adjtime        = hv_ptp_adjtime,
 742         .adjfine        = hv_ptp_adjfine,
 743         .gettime64      = hv_ptp_gettime,
 744         .settime64      = hv_ptp_settime,
 745         .owner          = THIS_MODULE,
 746 };
 747
 748 static struct ptp_clock *hv_ptp_clock;
 749
 750 static int hv_timesync_init(struct hv_util_service *srv)
 751 {
 752         spin_lock_init(&host_ts.lock);
 753
 754         INIT_WORK(&adj_time_work, hv_set_host_time);
 755
 756         /*
 757          * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
 758          * disabled but the driver is still useful without the PTP device
 759          * as it still handles the ICTIMESYNCFLAG_SYNC case.
 760          */
 761         hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
 762         if (IS_ERR_OR_NULL(hv_ptp_clock)) {
 763                 pr_err("cannot register PTP clock: %d\n",
 764                        PTR_ERR_OR_ZERO(hv_ptp_clock));
 765                 hv_ptp_clock = NULL;
 766         }
 767
 768         return 0;
 769 }
 770
 771 static void hv_timesync_cancel_work(void)
 772 {
 773         cancel_work_sync(&adj_time_work);
 774 }
 775
 776 static int hv_timesync_pre_suspend(void)
 777 {
 778         hv_timesync_cancel_work();
 779         return 0;
 780 }
 781
 782 static void hv_timesync_deinit(void)
 783 {
 784         if (hv_ptp_clock)
 785                 ptp_clock_unregister(hv_ptp_clock);
 786
 787         hv_timesync_cancel_work();
 788 }
 789
 790 static int __init init_hyperv_utils(void)
 791 {
 792         pr_info("Registering HyperV Utility Driver\n");
 793
 794         return vmbus_driver_register(&util_drv);
 795 }
 796
 797 static void exit_hyperv_utils(void)
 798 {
 799         pr_info("De-Registered HyperV Utility Driver\n");
 800
 801         vmbus_driver_unregister(&util_drv);
 802 }
 803
 804 module_init(init_hyperv_utils);
 805 module_exit(exit_hyperv_utils);
 806
 807 MODULE_DESCRIPTION("Hyper-V Utilities");
 808 MODULE_LICENSE("GPL");