drivers/hv/vmbus_drv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   5  * Authors:
   6  *   Haiyang Zhang <haiyangz@microsoft.com>
   7  *   Hank Janssen  <hjanssen@microsoft.com>
   8  *   K. Y. Srinivasan <kys@microsoft.com>
   9  */
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/device.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/sysctl.h>
  17 #include <linux/slab.h>
  18 #include <linux/acpi.h>
  19 #include <linux/completion.h>
  20 #include <linux/hyperv.h>
  21 #include <linux/kernel_stat.h>
  22 #include <linux/clockchips.h>
  23 #include <linux/cpu.h>
  24 #include <linux/sched/task_stack.h>
  25
  26 #include <linux/delay.h>
  27 #include <linux/notifier.h>
  28 #include <linux/ptrace.h>
  29 #include <linux/screen_info.h>
  30 #include <linux/kdebug.h>
  31 #include <linux/efi.h>
  32 #include <linux/random.h>
  33 #include <linux/kernel.h>
  34 #include <linux/syscore_ops.h>
  35 #include <clocksource/hyperv_timer.h>
  36 #include "hyperv_vmbus.h"
  37
  38 struct vmbus_dynid {
  39         struct list_head node;
  40         struct hv_vmbus_device_id id;
  41 };
  42
  43 static struct acpi_device  *hv_acpi_dev;
  44
  45 static struct completion probe_event;
  46
  47 static int hyperv_cpuhp_online;
  48
  49 static void *hv_panic_page;
  50
  51 /* Values parsed from ACPI DSDT */
  52 static int vmbus_irq;
  53 int vmbus_interrupt;
  54
  55 /*
  56  * Boolean to control whether to report panic messages over Hyper-V.
  57  *
  58  * It can be set via /proc/sys/kernel/hyperv_record_panic_msg
  59  */
  60 static int sysctl_record_panic_msg = 1;
  61
  62 static int hyperv_report_reg(void)
  63 {
  64         return !sysctl_record_panic_msg || !hv_panic_page;
  65 }
  66
  67 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
  68                               void *args)
  69 {
  70         struct pt_regs *regs;
  71
  72         vmbus_initiate_unload(true);
  73
  74         /*
  75          * Hyper-V should be notified only once about a panic.  If we will be
  76          * doing hyperv_report_panic_msg() later with kmsg data, don't do
  77          * the notification here.
  78          */
  79         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
  80             && hyperv_report_reg()) {
  81                 regs = current_pt_regs();
  82                 hyperv_report_panic(regs, val, false);
  83         }
  84         return NOTIFY_DONE;
  85 }
  86
  87 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
  88                             void *args)
  89 {
  90         struct die_args *die = args;
  91         struct pt_regs *regs = die->regs;
  92
  93         /* Don't notify Hyper-V if the die event is other than oops */
  94         if (val != DIE_OOPS)
  95                 return NOTIFY_DONE;
  96
  97         /*
  98          * Hyper-V should be notified only once about a panic.  If we will be
  99          * doing hyperv_report_panic_msg() later with kmsg data, don't do
 100          * the notification here.
 101          */
 102         if (hyperv_report_reg())
 103                 hyperv_report_panic(regs, val, true);
 104         return NOTIFY_DONE;
 105 }
 106
 107 static struct notifier_block hyperv_die_block = {
 108         .notifier_call = hyperv_die_event,
 109 };
 110 static struct notifier_block hyperv_panic_block = {
 111         .notifier_call = hyperv_panic_event,
 112 };
 113
 114 static const char *fb_mmio_name = "fb_range";
 115 static struct resource *fb_mmio;
 116 static struct resource *hyperv_mmio;
 117 static DEFINE_MUTEX(hyperv_mmio_lock);
 118
 119 static int vmbus_exists(void)
 120 {
 121         if (hv_acpi_dev == NULL)
 122                 return -ENODEV;
 123
 124         return 0;
 125 }
 126
 127 static u8 channel_monitor_group(const struct vmbus_channel *channel)
 128 {
 129         return (u8)channel->offermsg.monitorid / 32;
 130 }
 131
 132 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
 133 {
 134         return (u8)channel->offermsg.monitorid % 32;
 135 }
 136
 137 static u32 channel_pending(const struct vmbus_channel *channel,
 138                            const struct hv_monitor_page *monitor_page)
 139 {
 140         u8 monitor_group = channel_monitor_group(channel);
 141
 142         return monitor_page->trigger_group[monitor_group].pending;
 143 }
 144
 145 static u32 channel_latency(const struct vmbus_channel *channel,
 146                            const struct hv_monitor_page *monitor_page)
 147 {
 148         u8 monitor_group = channel_monitor_group(channel);
 149         u8 monitor_offset = channel_monitor_offset(channel);
 150
 151         return monitor_page->latency[monitor_group][monitor_offset];
 152 }
 153
 154 static u32 channel_conn_id(struct vmbus_channel *channel,
 155                            struct hv_monitor_page *monitor_page)
 156 {
 157         u8 monitor_group = channel_monitor_group(channel);
 158         u8 monitor_offset = channel_monitor_offset(channel);
 159
 160         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 161 }
 162
 163 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 164                        char *buf)
 165 {
 166         struct hv_device *hv_dev = device_to_hv_device(dev);
 167
 168         if (!hv_dev->channel)
 169                 return -ENODEV;
 170         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 171 }
 172 static DEVICE_ATTR_RO(id);
 173
 174 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 175                           char *buf)
 176 {
 177         struct hv_device *hv_dev = device_to_hv_device(dev);
 178
 179         if (!hv_dev->channel)
 180                 return -ENODEV;
 181         return sprintf(buf, "%d\n", hv_dev->channel->state);
 182 }
 183 static DEVICE_ATTR_RO(state);
 184
 185 static ssize_t monitor_id_show(struct device *dev,
 186                                struct device_attribute *dev_attr, char *buf)
 187 {
 188         struct hv_device *hv_dev = device_to_hv_device(dev);
 189
 190         if (!hv_dev->channel)
 191                 return -ENODEV;
 192         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
 193 }
 194 static DEVICE_ATTR_RO(monitor_id);
 195
 196 static ssize_t class_id_show(struct device *dev,
 197                                struct device_attribute *dev_attr, char *buf)
 198 {
 199         struct hv_device *hv_dev = device_to_hv_device(dev);
 200
 201         if (!hv_dev->channel)
 202                 return -ENODEV;
 203         return sprintf(buf, "{%pUl}\n",
 204                        &hv_dev->channel->offermsg.offer.if_type);
 205 }
 206 static DEVICE_ATTR_RO(class_id);
 207
 208 static ssize_t device_id_show(struct device *dev,
 209                               struct device_attribute *dev_attr, char *buf)
 210 {
 211         struct hv_device *hv_dev = device_to_hv_device(dev);
 212
 213         if (!hv_dev->channel)
 214                 return -ENODEV;
 215         return sprintf(buf, "{%pUl}\n",
 216                        &hv_dev->channel->offermsg.offer.if_instance);
 217 }
 218 static DEVICE_ATTR_RO(device_id);
 219
 220 static ssize_t modalias_show(struct device *dev,
 221                              struct device_attribute *dev_attr, char *buf)
 222 {
 223         struct hv_device *hv_dev = device_to_hv_device(dev);
 224
 225         return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
 226 }
 227 static DEVICE_ATTR_RO(modalias);
 228
 229 #ifdef CONFIG_NUMA
 230 static ssize_t numa_node_show(struct device *dev,
 231                               struct device_attribute *attr, char *buf)
 232 {
 233         struct hv_device *hv_dev = device_to_hv_device(dev);
 234
 235         if (!hv_dev->channel)
 236                 return -ENODEV;
 237
 238         return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
 239 }
 240 static DEVICE_ATTR_RO(numa_node);
 241 #endif
 242
 243 static ssize_t server_monitor_pending_show(struct device *dev,
 244                                            struct device_attribute *dev_attr,
 245                                            char *buf)
 246 {
 247         struct hv_device *hv_dev = device_to_hv_device(dev);
 248
 249         if (!hv_dev->channel)
 250                 return -ENODEV;
 251         return sprintf(buf, "%d\n",
 252                        channel_pending(hv_dev->channel,
 253                                        vmbus_connection.monitor_pages[0]));
 254 }
 255 static DEVICE_ATTR_RO(server_monitor_pending);
 256
 257 static ssize_t client_monitor_pending_show(struct device *dev,
 258                                            struct device_attribute *dev_attr,
 259                                            char *buf)
 260 {
 261         struct hv_device *hv_dev = device_to_hv_device(dev);
 262
 263         if (!hv_dev->channel)
 264                 return -ENODEV;
 265         return sprintf(buf, "%d\n",
 266                        channel_pending(hv_dev->channel,
 267                                        vmbus_connection.monitor_pages[1]));
 268 }
 269 static DEVICE_ATTR_RO(client_monitor_pending);
 270
 271 static ssize_t server_monitor_latency_show(struct device *dev,
 272                                            struct device_attribute *dev_attr,
 273                                            char *buf)
 274 {
 275         struct hv_device *hv_dev = device_to_hv_device(dev);
 276
 277         if (!hv_dev->channel)
 278                 return -ENODEV;
 279         return sprintf(buf, "%d\n",
 280                        channel_latency(hv_dev->channel,
 281                                        vmbus_connection.monitor_pages[0]));
 282 }
 283 static DEVICE_ATTR_RO(server_monitor_latency);
 284
 285 static ssize_t client_monitor_latency_show(struct device *dev,
 286                                            struct device_attribute *dev_attr,
 287                                            char *buf)
 288 {
 289         struct hv_device *hv_dev = device_to_hv_device(dev);
 290
 291         if (!hv_dev->channel)
 292                 return -ENODEV;
 293         return sprintf(buf, "%d\n",
 294                        channel_latency(hv_dev->channel,
 295                                        vmbus_connection.monitor_pages[1]));
 296 }
 297 static DEVICE_ATTR_RO(client_monitor_latency);
 298
 299 static ssize_t server_monitor_conn_id_show(struct device *dev,
 300                                            struct device_attribute *dev_attr,
 301                                            char *buf)
 302 {
 303         struct hv_device *hv_dev = device_to_hv_device(dev);
 304
 305         if (!hv_dev->channel)
 306                 return -ENODEV;
 307         return sprintf(buf, "%d\n",
 308                        channel_conn_id(hv_dev->channel,
 309                                        vmbus_connection.monitor_pages[0]));
 310 }
 311 static DEVICE_ATTR_RO(server_monitor_conn_id);
 312
 313 static ssize_t client_monitor_conn_id_show(struct device *dev,
 314                                            struct device_attribute *dev_attr,
 315                                            char *buf)
 316 {
 317         struct hv_device *hv_dev = device_to_hv_device(dev);
 318
 319         if (!hv_dev->channel)
 320                 return -ENODEV;
 321         return sprintf(buf, "%d\n",
 322                        channel_conn_id(hv_dev->channel,
 323                                        vmbus_connection.monitor_pages[1]));
 324 }
 325 static DEVICE_ATTR_RO(client_monitor_conn_id);
 326
 327 static ssize_t out_intr_mask_show(struct device *dev,
 328                                   struct device_attribute *dev_attr, char *buf)
 329 {
 330         struct hv_device *hv_dev = device_to_hv_device(dev);
 331         struct hv_ring_buffer_debug_info outbound;
 332         int ret;
 333
 334         if (!hv_dev->channel)
 335                 return -ENODEV;
 336
 337         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 338                                           &outbound);
 339         if (ret < 0)
 340                 return ret;
 341
 342         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 343 }
 344 static DEVICE_ATTR_RO(out_intr_mask);
 345
 346 static ssize_t out_read_index_show(struct device *dev,
 347                                    struct device_attribute *dev_attr, char *buf)
 348 {
 349         struct hv_device *hv_dev = device_to_hv_device(dev);
 350         struct hv_ring_buffer_debug_info outbound;
 351         int ret;
 352
 353         if (!hv_dev->channel)
 354                 return -ENODEV;
 355
 356         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 357                                           &outbound);
 358         if (ret < 0)
 359                 return ret;
 360         return sprintf(buf, "%d\n", outbound.current_read_index);
 361 }
 362 static DEVICE_ATTR_RO(out_read_index);
 363
 364 static ssize_t out_write_index_show(struct device *dev,
 365                                     struct device_attribute *dev_attr,
 366                                     char *buf)
 367 {
 368         struct hv_device *hv_dev = device_to_hv_device(dev);
 369         struct hv_ring_buffer_debug_info outbound;
 370         int ret;
 371
 372         if (!hv_dev->channel)
 373                 return -ENODEV;
 374
 375         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 376                                           &outbound);
 377         if (ret < 0)
 378                 return ret;
 379         return sprintf(buf, "%d\n", outbound.current_write_index);
 380 }
 381 static DEVICE_ATTR_RO(out_write_index);
 382
 383 static ssize_t out_read_bytes_avail_show(struct device *dev,
 384                                          struct device_attribute *dev_attr,
 385                                          char *buf)
 386 {
 387         struct hv_device *hv_dev = device_to_hv_device(dev);
 388         struct hv_ring_buffer_debug_info outbound;
 389         int ret;
 390
 391         if (!hv_dev->channel)
 392                 return -ENODEV;
 393
 394         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 395                                           &outbound);
 396         if (ret < 0)
 397                 return ret;
 398         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 399 }
 400 static DEVICE_ATTR_RO(out_read_bytes_avail);
 401
 402 static ssize_t out_write_bytes_avail_show(struct device *dev,
 403                                           struct device_attribute *dev_attr,
 404                                           char *buf)
 405 {
 406         struct hv_device *hv_dev = device_to_hv_device(dev);
 407         struct hv_ring_buffer_debug_info outbound;
 408         int ret;
 409
 410         if (!hv_dev->channel)
 411                 return -ENODEV;
 412
 413         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 414                                           &outbound);
 415         if (ret < 0)
 416                 return ret;
 417         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 418 }
 419 static DEVICE_ATTR_RO(out_write_bytes_avail);
 420
 421 static ssize_t in_intr_mask_show(struct device *dev,
 422                                  struct device_attribute *dev_attr, char *buf)
 423 {
 424         struct hv_device *hv_dev = device_to_hv_device(dev);
 425         struct hv_ring_buffer_debug_info inbound;
 426         int ret;
 427
 428         if (!hv_dev->channel)
 429                 return -ENODEV;
 430
 431         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 432         if (ret < 0)
 433                 return ret;
 434
 435         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 436 }
 437 static DEVICE_ATTR_RO(in_intr_mask);
 438
 439 static ssize_t in_read_index_show(struct device *dev,
 440                                   struct device_attribute *dev_attr, char *buf)
 441 {
 442         struct hv_device *hv_dev = device_to_hv_device(dev);
 443         struct hv_ring_buffer_debug_info inbound;
 444         int ret;
 445
 446         if (!hv_dev->channel)
 447                 return -ENODEV;
 448
 449         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 450         if (ret < 0)
 451                 return ret;
 452
 453         return sprintf(buf, "%d\n", inbound.current_read_index);
 454 }
 455 static DEVICE_ATTR_RO(in_read_index);
 456
 457 static ssize_t in_write_index_show(struct device *dev,
 458                                    struct device_attribute *dev_attr, char *buf)
 459 {
 460         struct hv_device *hv_dev = device_to_hv_device(dev);
 461         struct hv_ring_buffer_debug_info inbound;
 462         int ret;
 463
 464         if (!hv_dev->channel)
 465                 return -ENODEV;
 466
 467         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 468         if (ret < 0)
 469                 return ret;
 470
 471         return sprintf(buf, "%d\n", inbound.current_write_index);
 472 }
 473 static DEVICE_ATTR_RO(in_write_index);
 474
 475 static ssize_t in_read_bytes_avail_show(struct device *dev,
 476                                         struct device_attribute *dev_attr,
 477                                         char *buf)
 478 {
 479         struct hv_device *hv_dev = device_to_hv_device(dev);
 480         struct hv_ring_buffer_debug_info inbound;
 481         int ret;
 482
 483         if (!hv_dev->channel)
 484                 return -ENODEV;
 485
 486         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 487         if (ret < 0)
 488                 return ret;
 489
 490         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 491 }
 492 static DEVICE_ATTR_RO(in_read_bytes_avail);
 493
 494 static ssize_t in_write_bytes_avail_show(struct device *dev,
 495                                          struct device_attribute *dev_attr,
 496                                          char *buf)
 497 {
 498         struct hv_device *hv_dev = device_to_hv_device(dev);
 499         struct hv_ring_buffer_debug_info inbound;
 500         int ret;
 501
 502         if (!hv_dev->channel)
 503                 return -ENODEV;
 504
 505         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 506         if (ret < 0)
 507                 return ret;
 508
 509         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 510 }
 511 static DEVICE_ATTR_RO(in_write_bytes_avail);
 512
 513 static ssize_t channel_vp_mapping_show(struct device *dev,
 514                                        struct device_attribute *dev_attr,
 515                                        char *buf)
 516 {
 517         struct hv_device *hv_dev = device_to_hv_device(dev);
 518         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 519         int buf_size = PAGE_SIZE, n_written, tot_written;
 520         struct list_head *cur;
 521
 522         if (!channel)
 523                 return -ENODEV;
 524
 525         mutex_lock(&vmbus_connection.channel_mutex);
 526
 527         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 528                 channel->offermsg.child_relid, channel->target_cpu);
 529
 530         list_for_each(cur, &channel->sc_list) {
 531                 if (tot_written >= buf_size - 1)
 532                         break;
 533
 534                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 535                 n_written = scnprintf(buf + tot_written,
 536                                      buf_size - tot_written,
 537                                      "%u:%u\n",
 538                                      cur_sc->offermsg.child_relid,
 539                                      cur_sc->target_cpu);
 540                 tot_written += n_written;
 541         }
 542
 543         mutex_unlock(&vmbus_connection.channel_mutex);
 544
 545         return tot_written;
 546 }
 547 static DEVICE_ATTR_RO(channel_vp_mapping);
 548
 549 static ssize_t vendor_show(struct device *dev,
 550                            struct device_attribute *dev_attr,
 551                            char *buf)
 552 {
 553         struct hv_device *hv_dev = device_to_hv_device(dev);
 554
 555         return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
 556 }
 557 static DEVICE_ATTR_RO(vendor);
 558
 559 static ssize_t device_show(struct device *dev,
 560                            struct device_attribute *dev_attr,
 561                            char *buf)
 562 {
 563         struct hv_device *hv_dev = device_to_hv_device(dev);
 564
 565         return sprintf(buf, "0x%x\n", hv_dev->device_id);
 566 }
 567 static DEVICE_ATTR_RO(device);
 568
 569 static ssize_t driver_override_store(struct device *dev,
 570                                      struct device_attribute *attr,
 571                                      const char *buf, size_t count)
 572 {
 573         struct hv_device *hv_dev = device_to_hv_device(dev);
 574         char *driver_override, *old, *cp;
 575
 576         /* We need to keep extra room for a newline */
 577         if (count >= (PAGE_SIZE - 1))
 578                 return -EINVAL;
 579
 580         driver_override = kstrndup(buf, count, GFP_KERNEL);
 581         if (!driver_override)
 582                 return -ENOMEM;
 583
 584         cp = strchr(driver_override, '\n');
 585         if (cp)
 586                 *cp = '\0';
 587
 588         device_lock(dev);
 589         old = hv_dev->driver_override;
 590         if (strlen(driver_override)) {
 591                 hv_dev->driver_override = driver_override;
 592         } else {
 593                 kfree(driver_override);
 594                 hv_dev->driver_override = NULL;
 595         }
 596         device_unlock(dev);
 597
 598         kfree(old);
 599
 600         return count;
 601 }
 602
 603 static ssize_t driver_override_show(struct device *dev,
 604                                     struct device_attribute *attr, char *buf)
 605 {
 606         struct hv_device *hv_dev = device_to_hv_device(dev);
 607         ssize_t len;
 608
 609         device_lock(dev);
 610         len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
 611         device_unlock(dev);
 612
 613         return len;
 614 }
 615 static DEVICE_ATTR_RW(driver_override);
 616
 617 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 618 static struct attribute *vmbus_dev_attrs[] = {
 619         &dev_attr_id.attr,
 620         &dev_attr_state.attr,
 621         &dev_attr_monitor_id.attr,
 622         &dev_attr_class_id.attr,
 623         &dev_attr_device_id.attr,
 624         &dev_attr_modalias.attr,
 625 #ifdef CONFIG_NUMA
 626         &dev_attr_numa_node.attr,
 627 #endif
 628         &dev_attr_server_monitor_pending.attr,
 629         &dev_attr_client_monitor_pending.attr,
 630         &dev_attr_server_monitor_latency.attr,
 631         &dev_attr_client_monitor_latency.attr,
 632         &dev_attr_server_monitor_conn_id.attr,
 633         &dev_attr_client_monitor_conn_id.attr,
 634         &dev_attr_out_intr_mask.attr,
 635         &dev_attr_out_read_index.attr,
 636         &dev_attr_out_write_index.attr,
 637         &dev_attr_out_read_bytes_avail.attr,
 638         &dev_attr_out_write_bytes_avail.attr,
 639         &dev_attr_in_intr_mask.attr,
 640         &dev_attr_in_read_index.attr,
 641         &dev_attr_in_write_index.attr,
 642         &dev_attr_in_read_bytes_avail.attr,
 643         &dev_attr_in_write_bytes_avail.attr,
 644         &dev_attr_channel_vp_mapping.attr,
 645         &dev_attr_vendor.attr,
 646         &dev_attr_device.attr,
 647         &dev_attr_driver_override.attr,
 648         NULL,
 649 };
 650
 651 /*
 652  * Device-level attribute_group callback function. Returns the permission for
 653  * each attribute, and returns 0 if an attribute is not visible.
 654  */
 655 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
 656                                          struct attribute *attr, int idx)
 657 {
 658         struct device *dev = kobj_to_dev(kobj);
 659         const struct hv_device *hv_dev = device_to_hv_device(dev);
 660
 661         /* Hide the monitor attributes if the monitor mechanism is not used. */
 662         if (!hv_dev->channel->offermsg.monitor_allocated &&
 663             (attr == &dev_attr_monitor_id.attr ||
 664              attr == &dev_attr_server_monitor_pending.attr ||
 665              attr == &dev_attr_client_monitor_pending.attr ||
 666              attr == &dev_attr_server_monitor_latency.attr ||
 667              attr == &dev_attr_client_monitor_latency.attr ||
 668              attr == &dev_attr_server_monitor_conn_id.attr ||
 669              attr == &dev_attr_client_monitor_conn_id.attr))
 670                 return 0;
 671
 672         return attr->mode;
 673 }
 674
 675 static const struct attribute_group vmbus_dev_group = {
 676         .attrs = vmbus_dev_attrs,
 677         .is_visible = vmbus_dev_attr_is_visible
 678 };
 679 __ATTRIBUTE_GROUPS(vmbus_dev);
 680
 681 /*
 682  * vmbus_uevent - add uevent for our device
 683  *
 684  * This routine is invoked when a device is added or removed on the vmbus to
 685  * generate a uevent to udev in the userspace. The udev will then look at its
 686  * rule and the uevent generated here to load the appropriate driver
 687  *
 688  * The alias string will be of the form vmbus:guid where guid is the string
 689  * representation of the device guid (each byte of the guid will be
 690  * represented with two hex characters.
 691  */
 692 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 693 {
 694         struct hv_device *dev = device_to_hv_device(device);
 695         const char *format = "MODALIAS=vmbus:%*phN";
 696
 697         return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
 698 }
 699
 700 static const struct hv_vmbus_device_id *
 701 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
 702 {
 703         if (id == NULL)
 704                 return NULL; /* empty device table */
 705
 706         for (; !guid_is_null(&id->guid); id++)
 707                 if (guid_equal(&id->guid, guid))
 708                         return id;
 709
 710         return NULL;
 711 }
 712
 713 static const struct hv_vmbus_device_id *
 714 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
 715 {
 716         const struct hv_vmbus_device_id *id = NULL;
 717         struct vmbus_dynid *dynid;
 718
 719         spin_lock(&drv->dynids.lock);
 720         list_for_each_entry(dynid, &drv->dynids.list, node) {
 721                 if (guid_equal(&dynid->id.guid, guid)) {
 722                         id = &dynid->id;
 723                         break;
 724                 }
 725         }
 726         spin_unlock(&drv->dynids.lock);
 727
 728         return id;
 729 }
 730
 731 static const struct hv_vmbus_device_id vmbus_device_null;
 732
 733 /*
 734  * Return a matching hv_vmbus_device_id pointer.
 735  * If there is no match, return NULL.
 736  */
 737 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
 738                                                         struct hv_device *dev)
 739 {
 740         const guid_t *guid = &dev->dev_type;
 741         const struct hv_vmbus_device_id *id;
 742
 743         /* When driver_override is set, only bind to the matching driver */
 744         if (dev->driver_override && strcmp(dev->driver_override, drv->name))
 745                 return NULL;
 746
 747         /* Look at the dynamic ids first, before the static ones */
 748         id = hv_vmbus_dynid_match(drv, guid);
 749         if (!id)
 750                 id = hv_vmbus_dev_match(drv->id_table, guid);
 751
 752         /* driver_override will always match, send a dummy id */
 753         if (!id && dev->driver_override)
 754                 id = &vmbus_device_null;
 755
 756         return id;
 757 }
 758
 759 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
 760 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
 761 {
 762         struct vmbus_dynid *dynid;
 763
 764         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
 765         if (!dynid)
 766                 return -ENOMEM;
 767
 768         dynid->id.guid = *guid;
 769
 770         spin_lock(&drv->dynids.lock);
 771         list_add_tail(&dynid->node, &drv->dynids.list);
 772         spin_unlock(&drv->dynids.lock);
 773
 774         return driver_attach(&drv->driver);
 775 }
 776
 777 static void vmbus_free_dynids(struct hv_driver *drv)
 778 {
 779         struct vmbus_dynid *dynid, *n;
 780
 781         spin_lock(&drv->dynids.lock);
 782         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 783                 list_del(&dynid->node);
 784                 kfree(dynid);
 785         }
 786         spin_unlock(&drv->dynids.lock);
 787 }
 788
 789 /*
 790  * store_new_id - sysfs frontend to vmbus_add_dynid()
 791  *
 792  * Allow GUIDs to be added to an existing driver via sysfs.
 793  */
 794 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
 795                             size_t count)
 796 {
 797         struct hv_driver *drv = drv_to_hv_drv(driver);
 798         guid_t guid;
 799         ssize_t retval;
 800
 801         retval = guid_parse(buf, &guid);
 802         if (retval)
 803                 return retval;
 804
 805         if (hv_vmbus_dynid_match(drv, &guid))
 806                 return -EEXIST;
 807
 808         retval = vmbus_add_dynid(drv, &guid);
 809         if (retval)
 810                 return retval;
 811         return count;
 812 }
 813 static DRIVER_ATTR_WO(new_id);
 814
 815 /*
 816  * store_remove_id - remove a PCI device ID from this driver
 817  *
 818  * Removes a dynamic pci device ID to this driver.
 819  */
 820 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 821                                size_t count)
 822 {
 823         struct hv_driver *drv = drv_to_hv_drv(driver);
 824         struct vmbus_dynid *dynid, *n;
 825         guid_t guid;
 826         ssize_t retval;
 827
 828         retval = guid_parse(buf, &guid);
 829         if (retval)
 830                 return retval;
 831
 832         retval = -ENODEV;
 833         spin_lock(&drv->dynids.lock);
 834         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 835                 struct hv_vmbus_device_id *id = &dynid->id;
 836
 837                 if (guid_equal(&id->guid, &guid)) {
 838                         list_del(&dynid->node);
 839                         kfree(dynid);
 840                         retval = count;
 841                         break;
 842                 }
 843         }
 844         spin_unlock(&drv->dynids.lock);
 845
 846         return retval;
 847 }
 848 static DRIVER_ATTR_WO(remove_id);
 849
 850 static struct attribute *vmbus_drv_attrs[] = {
 851         &driver_attr_new_id.attr,
 852         &driver_attr_remove_id.attr,
 853         NULL,
 854 };
 855 ATTRIBUTE_GROUPS(vmbus_drv);
 856
 857
 858 /*
 859  * vmbus_match - Attempt to match the specified device to the specified driver
 860  */
 861 static int vmbus_match(struct device *device, struct device_driver *driver)
 862 {
 863         struct hv_driver *drv = drv_to_hv_drv(driver);
 864         struct hv_device *hv_dev = device_to_hv_device(device);
 865
 866         /* The hv_sock driver handles all hv_sock offers. */
 867         if (is_hvsock_channel(hv_dev->channel))
 868                 return drv->hvsock;
 869
 870         if (hv_vmbus_get_id(drv, hv_dev))
 871                 return 1;
 872
 873         return 0;
 874 }
 875
 876 /*
 877  * vmbus_probe - Add the new vmbus's child device
 878  */
 879 static int vmbus_probe(struct device *child_device)
 880 {
 881         int ret = 0;
 882         struct hv_driver *drv =
 883                         drv_to_hv_drv(child_device->driver);
 884         struct hv_device *dev = device_to_hv_device(child_device);
 885         const struct hv_vmbus_device_id *dev_id;
 886
 887         dev_id = hv_vmbus_get_id(drv, dev);
 888         if (drv->probe) {
 889                 ret = drv->probe(dev, dev_id);
 890                 if (ret != 0)
 891                         pr_err("probe failed for device %s (%d)\n",
 892                                dev_name(child_device), ret);
 893
 894         } else {
 895                 pr_err("probe not set for driver %s\n",
 896                        dev_name(child_device));
 897                 ret = -ENODEV;
 898         }
 899         return ret;
 900 }
 901
 902 /*
 903  * vmbus_remove - Remove a vmbus device
 904  */
 905 static int vmbus_remove(struct device *child_device)
 906 {
 907         struct hv_driver *drv;
 908         struct hv_device *dev = device_to_hv_device(child_device);
 909
 910         if (child_device->driver) {
 911                 drv = drv_to_hv_drv(child_device->driver);
 912                 if (drv->remove)
 913                         drv->remove(dev);
 914         }
 915
 916         return 0;
 917 }
 918
 919
 920 /*
 921  * vmbus_shutdown - Shutdown a vmbus device
 922  */
 923 static void vmbus_shutdown(struct device *child_device)
 924 {
 925         struct hv_driver *drv;
 926         struct hv_device *dev = device_to_hv_device(child_device);
 927
 928
 929         /* The device may not be attached yet */
 930         if (!child_device->driver)
 931                 return;
 932
 933         drv = drv_to_hv_drv(child_device->driver);
 934
 935         if (drv->shutdown)
 936                 drv->shutdown(dev);
 937 }
 938
 939 #ifdef CONFIG_PM_SLEEP
 940 /*
 941  * vmbus_suspend - Suspend a vmbus device
 942  */
 943 static int vmbus_suspend(struct device *child_device)
 944 {
 945         struct hv_driver *drv;
 946         struct hv_device *dev = device_to_hv_device(child_device);
 947
 948         /* The device may not be attached yet */
 949         if (!child_device->driver)
 950                 return 0;
 951
 952         drv = drv_to_hv_drv(child_device->driver);
 953         if (!drv->suspend)
 954                 return -EOPNOTSUPP;
 955
 956         return drv->suspend(dev);
 957 }
 958
 959 /*
 960  * vmbus_resume - Resume a vmbus device
 961  */
 962 static int vmbus_resume(struct device *child_device)
 963 {
 964         struct hv_driver *drv;
 965         struct hv_device *dev = device_to_hv_device(child_device);
 966
 967         /* The device may not be attached yet */
 968         if (!child_device->driver)
 969                 return 0;
 970
 971         drv = drv_to_hv_drv(child_device->driver);
 972         if (!drv->resume)
 973                 return -EOPNOTSUPP;
 974
 975         return drv->resume(dev);
 976 }
 977 #else
 978 #define vmbus_suspend NULL
 979 #define vmbus_resume NULL
 980 #endif /* CONFIG_PM_SLEEP */
 981
 982 /*
 983  * vmbus_device_release - Final callback release of the vmbus child device
 984  */
 985 static void vmbus_device_release(struct device *device)
 986 {
 987         struct hv_device *hv_dev = device_to_hv_device(device);
 988         struct vmbus_channel *channel = hv_dev->channel;
 989
 990         hv_debug_rm_dev_dir(hv_dev);
 991
 992         mutex_lock(&vmbus_connection.channel_mutex);
 993         hv_process_channel_removal(channel);
 994         mutex_unlock(&vmbus_connection.channel_mutex);
 995         kfree(hv_dev);
 996 }
 997
 998 /*
 999  * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
1000  *
1001  * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
1002  * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
1003  * is no way to wake up a Generation-2 VM.
1004  *
1005  * The other 4 ops are for hibernation.
1006  */
1007
1008 static const struct dev_pm_ops vmbus_pm = {
1009         .suspend_noirq  = NULL,
1010         .resume_noirq   = NULL,
1011         .freeze_noirq   = vmbus_suspend,
1012         .thaw_noirq     = vmbus_resume,
1013         .poweroff_noirq = vmbus_suspend,
1014         .restore_noirq  = vmbus_resume,
1015 };
1016
1017 /* The one and only one */
1018 static struct bus_type  hv_bus = {
1019         .name =         "vmbus",
1020         .match =                vmbus_match,
1021         .shutdown =             vmbus_shutdown,
1022         .remove =               vmbus_remove,
1023         .probe =                vmbus_probe,
1024         .uevent =               vmbus_uevent,
1025         .dev_groups =           vmbus_dev_groups,
1026         .drv_groups =           vmbus_drv_groups,
1027         .pm =                   &vmbus_pm,
1028 };
1029
1030 struct onmessage_work_context {
1031         struct work_struct work;
1032         struct {
1033                 struct hv_message_header header;
1034                 u8 payload[];
1035         } msg;
1036 };
1037
1038 static void vmbus_onmessage_work(struct work_struct *work)
1039 {
1040         struct onmessage_work_context *ctx;
1041
1042         /* Do not process messages if we're in DISCONNECTED state */
1043         if (vmbus_connection.conn_state == DISCONNECTED)
1044                 return;
1045
1046         ctx = container_of(work, struct onmessage_work_context,
1047                            work);
1048         vmbus_onmessage((struct vmbus_channel_message_header *)
1049                         &ctx->msg.payload);
1050         kfree(ctx);
1051 }
1052
1053 void vmbus_on_msg_dpc(unsigned long data)
1054 {
1055         struct hv_per_cpu_context *hv_cpu = (void *)data;
1056         void *page_addr = hv_cpu->synic_message_page;
1057         struct hv_message *msg = (struct hv_message *)page_addr +
1058                                   VMBUS_MESSAGE_SINT;
1059         struct vmbus_channel_message_header *hdr;
1060         const struct vmbus_channel_message_table_entry *entry;
1061         struct onmessage_work_context *ctx;
1062         u32 message_type = msg->header.message_type;
1063
1064         /*
1065          * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
1066          * it is being used in 'struct vmbus_channel_message_header' definition
1067          * which is supposed to match hypervisor ABI.
1068          */
1069         BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
1070
1071         if (message_type == HVMSG_NONE)
1072                 /* no msg */
1073                 return;
1074
1075         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
1076
1077         trace_vmbus_on_msg_dpc(hdr);
1078
1079         if (hdr->msgtype >= CHANNELMSG_COUNT) {
1080                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
1081                 goto msg_handled;
1082         }
1083
1084         if (msg->header.payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
1085                 WARN_ONCE(1, "payload size is too large (%d)\n",
1086                           msg->header.payload_size);
1087                 goto msg_handled;
1088         }
1089
1090         entry = &channel_message_table[hdr->msgtype];
1091
1092         if (!entry->message_handler)
1093                 goto msg_handled;
1094
1095         if (msg->header.payload_size < entry->min_payload_len) {
1096                 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n",
1097                           hdr->msgtype, msg->header.payload_size);
1098                 goto msg_handled;
1099         }
1100
1101         if (entry->handler_type == VMHT_BLOCKING) {
1102                 ctx = kmalloc(sizeof(*ctx) + msg->header.payload_size,
1103                               GFP_ATOMIC);
1104                 if (ctx == NULL)
1105                         return;
1106
1107                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1108                 memcpy(&ctx->msg, msg, sizeof(msg->header) +
1109                        msg->header.payload_size);
1110
1111                 /*
1112                  * The host can generate a rescind message while we
1113                  * may still be handling the original offer. We deal with
1114                  * this condition by relying on the synchronization provided
1115                  * by offer_in_progress and by channel_mutex.  See also the
1116                  * inline comments in vmbus_onoffer_rescind().
1117                  */
1118                 switch (hdr->msgtype) {
1119                 case CHANNELMSG_RESCIND_CHANNELOFFER:
1120                         /*
1121                          * If we are handling the rescind message;
1122                          * schedule the work on the global work queue.
1123                          *
1124                          * The OFFER message and the RESCIND message should
1125                          * not be handled by the same serialized work queue,
1126                          * because the OFFER handler may call vmbus_open(),
1127                          * which tries to open the channel by sending an
1128                          * OPEN_CHANNEL message to the host and waits for
1129                          * the host's response; however, if the host has
1130                          * rescinded the channel before it receives the
1131                          * OPEN_CHANNEL message, the host just silently
1132                          * ignores the OPEN_CHANNEL message; as a result,
1133                          * the guest's OFFER handler hangs for ever, if we
1134                          * handle the RESCIND message in the same serialized
1135                          * work queue: the RESCIND handler can not start to
1136                          * run before the OFFER handler finishes.
1137                          */
1138                         schedule_work(&ctx->work);
1139                         break;
1140
1141                 case CHANNELMSG_OFFERCHANNEL:
1142                         /*
1143                          * The host sends the offer message of a given channel
1144                          * before sending the rescind message of the same
1145                          * channel.  These messages are sent to the guest's
1146                          * connect CPU; the guest then starts processing them
1147                          * in the tasklet handler on this CPU:
1148                          *
1149                          * VMBUS_CONNECT_CPU
1150                          *
1151                          * [vmbus_on_msg_dpc()]
1152                          * atomic_inc()  // CHANNELMSG_OFFERCHANNEL
1153                          * queue_work()
1154                          * ...
1155                          * [vmbus_on_msg_dpc()]
1156                          * schedule_work()  // CHANNELMSG_RESCIND_CHANNELOFFER
1157                          *
1158                          * We rely on the memory-ordering properties of the
1159                          * queue_work() and schedule_work() primitives, which
1160                          * guarantee that the atomic increment will be visible
1161                          * to the CPUs which will execute the offer & rescind
1162                          * works by the time these works will start execution.
1163                          */
1164                         atomic_inc(&vmbus_connection.offer_in_progress);
1165                         fallthrough;
1166
1167                 default:
1168                         queue_work(vmbus_connection.work_queue, &ctx->work);
1169                 }
1170         } else
1171                 entry->message_handler(hdr);
1172
1173 msg_handled:
1174         vmbus_signal_eom(msg, message_type);
1175 }
1176
1177 #ifdef CONFIG_PM_SLEEP
1178 /*
1179  * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1180  * hibernation, because hv_sock connections can not persist across hibernation.
1181  */
1182 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1183 {
1184         struct onmessage_work_context *ctx;
1185         struct vmbus_channel_rescind_offer *rescind;
1186
1187         WARN_ON(!is_hvsock_channel(channel));
1188
1189         /*
1190          * Allocation size is small and the allocation should really not fail,
1191          * otherwise the state of the hv_sock connections ends up in limbo.
1192          */
1193         ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
1194                       GFP_KERNEL | __GFP_NOFAIL);
1195
1196         /*
1197          * So far, these are not really used by Linux. Just set them to the
1198          * reasonable values conforming to the definitions of the fields.
1199          */
1200         ctx->msg.header.message_type = 1;
1201         ctx->msg.header.payload_size = sizeof(*rescind);
1202
1203         /* These values are actually used by Linux. */
1204         rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
1205         rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1206         rescind->child_relid = channel->offermsg.child_relid;
1207
1208         INIT_WORK(&ctx->work, vmbus_onmessage_work);
1209
1210         queue_work(vmbus_connection.work_queue, &ctx->work);
1211 }
1212 #endif /* CONFIG_PM_SLEEP */
1213
1214 /*
1215  * Schedule all channels with events pending
1216  */
1217 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1218 {
1219         unsigned long *recv_int_page;
1220         u32 maxbits, relid;
1221
1222         if (vmbus_proto_version < VERSION_WIN8) {
1223                 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1224                 recv_int_page = vmbus_connection.recv_int_page;
1225         } else {
1226                 /*
1227                  * When the host is win8 and beyond, the event page
1228                  * can be directly checked to get the id of the channel
1229                  * that has the interrupt pending.
1230                  */
1231                 void *page_addr = hv_cpu->synic_event_page;
1232                 union hv_synic_event_flags *event
1233                         = (union hv_synic_event_flags *)page_addr +
1234                                                  VMBUS_MESSAGE_SINT;
1235
1236                 maxbits = HV_EVENT_FLAGS_COUNT;
1237                 recv_int_page = event->flags;
1238         }
1239
1240         if (unlikely(!recv_int_page))
1241                 return;
1242
1243         for_each_set_bit(relid, recv_int_page, maxbits) {
1244                 void (*callback_fn)(void *context);
1245                 struct vmbus_channel *channel;
1246
1247                 if (!sync_test_and_clear_bit(relid, recv_int_page))
1248                         continue;
1249
1250                 /* Special case - vmbus channel protocol msg */
1251                 if (relid == 0)
1252                         continue;
1253
1254                 /*
1255                  * Pairs with the kfree_rcu() in vmbus_chan_release().
1256                  * Guarantees that the channel data structure doesn't
1257                  * get freed while the channel pointer below is being
1258                  * dereferenced.
1259                  */
1260                 rcu_read_lock();
1261
1262                 /* Find channel based on relid */
1263                 channel = relid2channel(relid);
1264                 if (channel == NULL)
1265                         goto sched_unlock_rcu;
1266
1267                 if (channel->rescind)
1268                         goto sched_unlock_rcu;
1269
1270                 /*
1271                  * Make sure that the ring buffer data structure doesn't get
1272                  * freed while we dereference the ring buffer pointer.  Test
1273                  * for the channel's onchannel_callback being NULL within a
1274                  * sched_lock critical section.  See also the inline comments
1275                  * in vmbus_reset_channel_cb().
1276                  */
1277                 spin_lock(&channel->sched_lock);
1278
1279                 callback_fn = channel->onchannel_callback;
1280                 if (unlikely(callback_fn == NULL))
1281                         goto sched_unlock;
1282
1283                 trace_vmbus_chan_sched(channel);
1284
1285                 ++channel->interrupts;
1286
1287                 switch (channel->callback_mode) {
1288                 case HV_CALL_ISR:
1289                         (*callback_fn)(channel->channel_callback_context);
1290                         break;
1291
1292                 case HV_CALL_BATCHED:
1293                         hv_begin_read(&channel->inbound);
1294                         fallthrough;
1295                 case HV_CALL_DIRECT:
1296                         tasklet_schedule(&channel->callback_event);
1297                 }
1298
1299 sched_unlock:
1300                 spin_unlock(&channel->sched_lock);
1301 sched_unlock_rcu:
1302                 rcu_read_unlock();
1303         }
1304 }
1305
1306 static void vmbus_isr(void)
1307 {
1308         struct hv_per_cpu_context *hv_cpu
1309                 = this_cpu_ptr(hv_context.cpu_context);
1310         void *page_addr = hv_cpu->synic_event_page;
1311         struct hv_message *msg;
1312         union hv_synic_event_flags *event;
1313         bool handled = false;
1314
1315         if (unlikely(page_addr == NULL))
1316                 return;
1317
1318         event = (union hv_synic_event_flags *)page_addr +
1319                                          VMBUS_MESSAGE_SINT;
1320         /*
1321          * Check for events before checking for messages. This is the order
1322          * in which events and messages are checked in Windows guests on
1323          * Hyper-V, and the Windows team suggested we do the same.
1324          */
1325
1326         if ((vmbus_proto_version == VERSION_WS2008) ||
1327                 (vmbus_proto_version == VERSION_WIN7)) {
1328
1329                 /* Since we are a child, we only need to check bit 0 */
1330                 if (sync_test_and_clear_bit(0, event->flags))
1331                         handled = true;
1332         } else {
1333                 /*
1334                  * Our host is win8 or above. The signaling mechanism
1335                  * has changed and we can directly look at the event page.
1336                  * If bit n is set then we have an interrup on the channel
1337                  * whose id is n.
1338                  */
1339                 handled = true;
1340         }
1341
1342         if (handled)
1343                 vmbus_chan_sched(hv_cpu);
1344
1345         page_addr = hv_cpu->synic_message_page;
1346         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1347
1348         /* Check if there are actual msgs to be processed */
1349         if (msg->header.message_type != HVMSG_NONE) {
1350                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1351                         hv_stimer0_isr();
1352                         vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1353                 } else
1354                         tasklet_schedule(&hv_cpu->msg_dpc);
1355         }
1356
1357         add_interrupt_randomness(hv_get_vector(), 0);
1358 }
1359
1360 /*
1361  * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1362  * buffer and call into Hyper-V to transfer the data.
1363  */
1364 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1365                          enum kmsg_dump_reason reason)
1366 {
1367         size_t bytes_written;
1368         phys_addr_t panic_pa;
1369
1370         /* We are only interested in panics. */
1371         if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1372                 return;
1373
1374         panic_pa = virt_to_phys(hv_panic_page);
1375
1376         /*
1377          * Write dump contents to the page. No need to synchronize; panic should
1378          * be single-threaded.
1379          */
1380         kmsg_dump_get_buffer(dumper, false, hv_panic_page, HV_HYP_PAGE_SIZE,
1381                              &bytes_written);
1382         if (bytes_written)
1383                 hyperv_report_panic_msg(panic_pa, bytes_written);
1384 }
1385
1386 static struct kmsg_dumper hv_kmsg_dumper = {
1387         .dump = hv_kmsg_dump,
1388 };
1389
1390 static void hv_kmsg_dump_register(void)
1391 {
1392         int ret;
1393
1394         hv_panic_page = hv_alloc_hyperv_zeroed_page();
1395         if (!hv_panic_page) {
1396                 pr_err("Hyper-V: panic message page memory allocation failed\n");
1397                 return;
1398         }
1399
1400         ret = kmsg_dump_register(&hv_kmsg_dumper);
1401         if (ret) {
1402                 pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret);
1403                 hv_free_hyperv_page((unsigned long)hv_panic_page);
1404                 hv_panic_page = NULL;
1405         }
1406 }
1407
1408 static struct ctl_table_header *hv_ctl_table_hdr;
1409
1410 /*
1411  * sysctl option to allow the user to control whether kmsg data should be
1412  * reported to Hyper-V on panic.
1413  */
1414 static struct ctl_table hv_ctl_table[] = {
1415         {
1416                 .procname       = "hyperv_record_panic_msg",
1417                 .data           = &sysctl_record_panic_msg,
1418                 .maxlen         = sizeof(int),
1419                 .mode           = 0644,
1420                 .proc_handler   = proc_dointvec_minmax,
1421                 .extra1         = SYSCTL_ZERO,
1422                 .extra2         = SYSCTL_ONE
1423         },
1424         {}
1425 };
1426
1427 static struct ctl_table hv_root_table[] = {
1428         {
1429                 .procname       = "kernel",
1430                 .mode           = 0555,
1431                 .child          = hv_ctl_table
1432         },
1433         {}
1434 };
1435
1436 /*
1437  * vmbus_bus_init -Main vmbus driver initialization routine.
1438  *
1439  * Here, we
1440  *      - initialize the vmbus driver context
1441  *      - invoke the vmbus hv main init routine
1442  *      - retrieve the channel offers
1443  */
1444 static int vmbus_bus_init(void)
1445 {
1446         int ret;
1447
1448         ret = hv_init();
1449         if (ret != 0) {
1450                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1451                 return ret;
1452         }
1453
1454         ret = bus_register(&hv_bus);
1455         if (ret)
1456                 return ret;
1457
1458         ret = hv_setup_vmbus_irq(vmbus_irq, vmbus_isr);
1459         if (ret)
1460                 goto err_setup;
1461
1462         ret = hv_synic_alloc();
1463         if (ret)
1464                 goto err_alloc;
1465
1466         /*
1467          * Initialize the per-cpu interrupt state and stimer state.
1468          * Then connect to the host.
1469          */
1470         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1471                                 hv_synic_init, hv_synic_cleanup);
1472         if (ret < 0)
1473                 goto err_cpuhp;
1474         hyperv_cpuhp_online = ret;
1475
1476         ret = vmbus_connect();
1477         if (ret)
1478                 goto err_connect;
1479
1480         /*
1481          * Only register if the crash MSRs are available
1482          */
1483         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1484                 u64 hyperv_crash_ctl;
1485                 /*
1486                  * Sysctl registration is not fatal, since by default
1487                  * reporting is enabled.
1488                  */
1489                 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1490                 if (!hv_ctl_table_hdr)
1491                         pr_err("Hyper-V: sysctl table register error");
1492
1493                 /*
1494                  * Register for panic kmsg callback only if the right
1495                  * capability is supported by the hypervisor.
1496                  */
1497                 hv_get_crash_ctl(hyperv_crash_ctl);
1498                 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG)
1499                         hv_kmsg_dump_register();
1500
1501                 register_die_notifier(&hyperv_die_block);
1502         }
1503
1504         /*
1505          * Always register the panic notifier because we need to unload
1506          * the VMbus channel connection to prevent any VMbus
1507          * activity after the VM panics.
1508          */
1509         atomic_notifier_chain_register(&panic_notifier_list,
1510                                &hyperv_panic_block);
1511
1512         vmbus_request_offers();
1513
1514         return 0;
1515
1516 err_connect:
1517         cpuhp_remove_state(hyperv_cpuhp_online);
1518 err_cpuhp:
1519         hv_synic_free();
1520 err_alloc:
1521         hv_remove_vmbus_irq();
1522 err_setup:
1523         bus_unregister(&hv_bus);
1524         unregister_sysctl_table(hv_ctl_table_hdr);
1525         hv_ctl_table_hdr = NULL;
1526         return ret;
1527 }
1528
1529 /**
1530  * __vmbus_child_driver_register() - Register a vmbus's driver
1531  * @hv_driver: Pointer to driver structure you want to register
1532  * @owner: owner module of the drv
1533  * @mod_name: module name string
1534  *
1535  * Registers the given driver with Linux through the 'driver_register()' call
1536  * and sets up the hyper-v vmbus handling for this driver.
1537  * It will return the state of the 'driver_register()' call.
1538  *
1539  */
1540 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1541 {
1542         int ret;
1543
1544         pr_info("registering driver %s\n", hv_driver->name);
1545
1546         ret = vmbus_exists();
1547         if (ret < 0)
1548                 return ret;
1549
1550         hv_driver->driver.name = hv_driver->name;
1551         hv_driver->driver.owner = owner;
1552         hv_driver->driver.mod_name = mod_name;
1553         hv_driver->driver.bus = &hv_bus;
1554
1555         spin_lock_init(&hv_driver->dynids.lock);
1556         INIT_LIST_HEAD(&hv_driver->dynids.list);
1557
1558         ret = driver_register(&hv_driver->driver);
1559
1560         return ret;
1561 }
1562 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1563
1564 /**
1565  * vmbus_driver_unregister() - Unregister a vmbus's driver
1566  * @hv_driver: Pointer to driver structure you want to
1567  *             un-register
1568  *
1569  * Un-register the given driver that was previous registered with a call to
1570  * vmbus_driver_register()
1571  */
1572 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1573 {
1574         pr_info("unregistering driver %s\n", hv_driver->name);
1575
1576         if (!vmbus_exists()) {
1577                 driver_unregister(&hv_driver->driver);
1578                 vmbus_free_dynids(hv_driver);
1579         }
1580 }
1581 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1582
1583
1584 /*
1585  * Called when last reference to channel is gone.
1586  */
1587 static void vmbus_chan_release(struct kobject *kobj)
1588 {
1589         struct vmbus_channel *channel
1590                 = container_of(kobj, struct vmbus_channel, kobj);
1591
1592         kfree_rcu(channel, rcu);
1593 }
1594
1595 struct vmbus_chan_attribute {
1596         struct attribute attr;
1597         ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1598         ssize_t (*store)(struct vmbus_channel *chan,
1599                          const char *buf, size_t count);
1600 };
1601 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1602         struct vmbus_chan_attribute chan_attr_##_name \
1603                 = __ATTR(_name, _mode, _show, _store)
1604 #define VMBUS_CHAN_ATTR_RW(_name) \
1605         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1606 #define VMBUS_CHAN_ATTR_RO(_name) \
1607         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1608 #define VMBUS_CHAN_ATTR_WO(_name) \
1609         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1610
1611 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1612                                     struct attribute *attr, char *buf)
1613 {
1614         const struct vmbus_chan_attribute *attribute
1615                 = container_of(attr, struct vmbus_chan_attribute, attr);
1616         struct vmbus_channel *chan
1617                 = container_of(kobj, struct vmbus_channel, kobj);
1618
1619         if (!attribute->show)
1620                 return -EIO;
1621
1622         return attribute->show(chan, buf);
1623 }
1624
1625 static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
1626                                      struct attribute *attr, const char *buf,
1627                                      size_t count)
1628 {
1629         const struct vmbus_chan_attribute *attribute
1630                 = container_of(attr, struct vmbus_chan_attribute, attr);
1631         struct vmbus_channel *chan
1632                 = container_of(kobj, struct vmbus_channel, kobj);
1633
1634         if (!attribute->store)
1635                 return -EIO;
1636
1637         return attribute->store(chan, buf, count);
1638 }
1639
1640 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1641         .show = vmbus_chan_attr_show,
1642         .store = vmbus_chan_attr_store,
1643 };
1644
1645 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1646 {
1647         struct hv_ring_buffer_info *rbi = &channel->outbound;
1648         ssize_t ret;
1649
1650         mutex_lock(&rbi->ring_buffer_mutex);
1651         if (!rbi->ring_buffer) {
1652                 mutex_unlock(&rbi->ring_buffer_mutex);
1653                 return -EINVAL;
1654         }
1655
1656         ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1657         mutex_unlock(&rbi->ring_buffer_mutex);
1658         return ret;
1659 }
1660 static VMBUS_CHAN_ATTR_RO(out_mask);
1661
1662 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1663 {
1664         struct hv_ring_buffer_info *rbi = &channel->inbound;
1665         ssize_t ret;
1666
1667         mutex_lock(&rbi->ring_buffer_mutex);
1668         if (!rbi->ring_buffer) {
1669                 mutex_unlock(&rbi->ring_buffer_mutex);
1670                 return -EINVAL;
1671         }
1672
1673         ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1674         mutex_unlock(&rbi->ring_buffer_mutex);
1675         return ret;
1676 }
1677 static VMBUS_CHAN_ATTR_RO(in_mask);
1678
1679 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1680 {
1681         struct hv_ring_buffer_info *rbi = &channel->inbound;
1682         ssize_t ret;
1683
1684         mutex_lock(&rbi->ring_buffer_mutex);
1685         if (!rbi->ring_buffer) {
1686                 mutex_unlock(&rbi->ring_buffer_mutex);
1687                 return -EINVAL;
1688         }
1689
1690         ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1691         mutex_unlock(&rbi->ring_buffer_mutex);
1692         return ret;
1693 }
1694 static VMBUS_CHAN_ATTR_RO(read_avail);
1695
1696 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1697 {
1698         struct hv_ring_buffer_info *rbi = &channel->outbound;
1699         ssize_t ret;
1700
1701         mutex_lock(&rbi->ring_buffer_mutex);
1702         if (!rbi->ring_buffer) {
1703                 mutex_unlock(&rbi->ring_buffer_mutex);
1704                 return -EINVAL;
1705         }
1706
1707         ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1708         mutex_unlock(&rbi->ring_buffer_mutex);
1709         return ret;
1710 }
1711 static VMBUS_CHAN_ATTR_RO(write_avail);
1712
1713 static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
1714 {
1715         return sprintf(buf, "%u\n", channel->target_cpu);
1716 }
1717 static ssize_t target_cpu_store(struct vmbus_channel *channel,
1718                                 const char *buf, size_t count)
1719 {
1720         u32 target_cpu, origin_cpu;
1721         ssize_t ret = count;
1722
1723         if (vmbus_proto_version < VERSION_WIN10_V4_1)
1724                 return -EIO;
1725
1726         if (sscanf(buf, "%uu", &target_cpu) != 1)
1727                 return -EIO;
1728
1729         /* Validate target_cpu for the cpumask_test_cpu() operation below. */
1730         if (target_cpu >= nr_cpumask_bits)
1731                 return -EINVAL;
1732
1733         /* No CPUs should come up or down during this. */
1734         cpus_read_lock();
1735
1736         if (!cpu_online(target_cpu)) {
1737                 cpus_read_unlock();
1738                 return -EINVAL;
1739         }
1740
1741         /*
1742          * Synchronizes target_cpu_store() and channel closure:
1743          *
1744          * { Initially: state = CHANNEL_OPENED }
1745          *
1746          * CPU1                         CPU2
1747          *
1748          * [target_cpu_store()]         [vmbus_disconnect_ring()]
1749          *
1750          * LOCK channel_mutex           LOCK channel_mutex
1751          * LOAD r1 = state              LOAD r2 = state
1752          * IF (r1 == CHANNEL_OPENED)    IF (r2 == CHANNEL_OPENED)
1753          *   SEND MODIFYCHANNEL           STORE state = CHANNEL_OPEN
1754          *   [...]                        SEND CLOSECHANNEL
1755          * UNLOCK channel_mutex         UNLOCK channel_mutex
1756          *
1757          * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
1758          *              CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
1759          *
1760          * Note.  The host processes the channel messages "sequentially", in
1761          * the order in which they are received on a per-partition basis.
1762          */
1763         mutex_lock(&vmbus_connection.channel_mutex);
1764
1765         /*
1766          * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
1767          * avoid sending the message and fail here for such channels.
1768          */
1769         if (channel->state != CHANNEL_OPENED_STATE) {
1770                 ret = -EIO;
1771                 goto cpu_store_unlock;
1772         }
1773
1774         origin_cpu = channel->target_cpu;
1775         if (target_cpu == origin_cpu)
1776                 goto cpu_store_unlock;
1777
1778         if (vmbus_send_modifychannel(channel->offermsg.child_relid,
1779                                      hv_cpu_number_to_vp_number(target_cpu))) {
1780                 ret = -EIO;
1781                 goto cpu_store_unlock;
1782         }
1783
1784         /*
1785          * Warning.  At this point, there is *no* guarantee that the host will
1786          * have successfully processed the vmbus_send_modifychannel() request.
1787          * See the header comment of vmbus_send_modifychannel() for more info.
1788          *
1789          * Lags in the processing of the above vmbus_send_modifychannel() can
1790          * result in missed interrupts if the "old" target CPU is taken offline
1791          * before Hyper-V starts sending interrupts to the "new" target CPU.
1792          * But apart from this offlining scenario, the code tolerates such
1793          * lags.  It will function correctly even if a channel interrupt comes
1794          * in on a CPU that is different from the channel target_cpu value.
1795          */
1796
1797         channel->target_cpu = target_cpu;
1798
1799         /* See init_vp_index(). */
1800         if (hv_is_perf_channel(channel))
1801                 hv_update_alloced_cpus(origin_cpu, target_cpu);
1802
1803         /* Currently set only for storvsc channels. */
1804         if (channel->change_target_cpu_callback) {
1805                 (*channel->change_target_cpu_callback)(channel,
1806                                 origin_cpu, target_cpu);
1807         }
1808
1809 cpu_store_unlock:
1810         mutex_unlock(&vmbus_connection.channel_mutex);
1811         cpus_read_unlock();
1812         return ret;
1813 }
1814 static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
1815
1816 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1817                                     char *buf)
1818 {
1819         return sprintf(buf, "%d\n",
1820                        channel_pending(channel,
1821                                        vmbus_connection.monitor_pages[1]));
1822 }
1823 static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL);
1824
1825 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1826                                     char *buf)
1827 {
1828         return sprintf(buf, "%d\n",
1829                        channel_latency(channel,
1830                                        vmbus_connection.monitor_pages[1]));
1831 }
1832 static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL);
1833
1834 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1835 {
1836         return sprintf(buf, "%llu\n", channel->interrupts);
1837 }
1838 static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL);
1839
1840 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1841 {
1842         return sprintf(buf, "%llu\n", channel->sig_events);
1843 }
1844 static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL);
1845
1846 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1847                                          char *buf)
1848 {
1849         return sprintf(buf, "%llu\n",
1850                        (unsigned long long)channel->intr_in_full);
1851 }
1852 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1853
1854 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1855                                            char *buf)
1856 {
1857         return sprintf(buf, "%llu\n",
1858                        (unsigned long long)channel->intr_out_empty);
1859 }
1860 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1861
1862 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1863                                            char *buf)
1864 {
1865         return sprintf(buf, "%llu\n",
1866                        (unsigned long long)channel->out_full_first);
1867 }
1868 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1869
1870 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1871                                            char *buf)
1872 {
1873         return sprintf(buf, "%llu\n",
1874                        (unsigned long long)channel->out_full_total);
1875 }
1876 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1877
1878 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1879                                           char *buf)
1880 {
1881         return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1882 }
1883 static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL);
1884
1885 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1886                                   char *buf)
1887 {
1888         return sprintf(buf, "%u\n",
1889                        channel->offermsg.offer.sub_channel_index);
1890 }
1891 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1892
1893 static struct attribute *vmbus_chan_attrs[] = {
1894         &chan_attr_out_mask.attr,
1895         &chan_attr_in_mask.attr,
1896         &chan_attr_read_avail.attr,
1897         &chan_attr_write_avail.attr,
1898         &chan_attr_cpu.attr,
1899         &chan_attr_pending.attr,
1900         &chan_attr_latency.attr,
1901         &chan_attr_interrupts.attr,
1902         &chan_attr_events.attr,
1903         &chan_attr_intr_in_full.attr,
1904         &chan_attr_intr_out_empty.attr,
1905         &chan_attr_out_full_first.attr,
1906         &chan_attr_out_full_total.attr,
1907         &chan_attr_monitor_id.attr,
1908         &chan_attr_subchannel_id.attr,
1909         NULL
1910 };
1911
1912 /*
1913  * Channel-level attribute_group callback function. Returns the permission for
1914  * each attribute, and returns 0 if an attribute is not visible.
1915  */
1916 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1917                                           struct attribute *attr, int idx)
1918 {
1919         const struct vmbus_channel *channel =
1920                 container_of(kobj, struct vmbus_channel, kobj);
1921
1922         /* Hide the monitor attributes if the monitor mechanism is not used. */
1923         if (!channel->offermsg.monitor_allocated &&
1924             (attr == &chan_attr_pending.attr ||
1925              attr == &chan_attr_latency.attr ||
1926              attr == &chan_attr_monitor_id.attr))
1927                 return 0;
1928
1929         return attr->mode;
1930 }
1931
1932 static struct attribute_group vmbus_chan_group = {
1933         .attrs = vmbus_chan_attrs,
1934         .is_visible = vmbus_chan_attr_is_visible
1935 };
1936
1937 static struct kobj_type vmbus_chan_ktype = {
1938         .sysfs_ops = &vmbus_chan_sysfs_ops,
1939         .release = vmbus_chan_release,
1940 };
1941
1942 /*
1943  * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1944  */
1945 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1946 {
1947         const struct device *device = &dev->device;
1948         struct kobject *kobj = &channel->kobj;
1949         u32 relid = channel->offermsg.child_relid;
1950         int ret;
1951
1952         kobj->kset = dev->channels_kset;
1953         ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1954                                    "%u", relid);
1955         if (ret)
1956                 return ret;
1957
1958         ret = sysfs_create_group(kobj, &vmbus_chan_group);
1959
1960         if (ret) {
1961                 /*
1962                  * The calling functions' error handling paths will cleanup the
1963                  * empty channel directory.
1964                  */
1965                 dev_err(device, "Unable to set up channel sysfs files\n");
1966                 return ret;
1967         }
1968
1969         kobject_uevent(kobj, KOBJ_ADD);
1970
1971         return 0;
1972 }
1973
1974 /*
1975  * vmbus_remove_channel_attr_group - remove the channel's attribute group
1976  */
1977 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1978 {
1979         sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1980 }
1981
1982 /*
1983  * vmbus_device_create - Creates and registers a new child device
1984  * on the vmbus.
1985  */
1986 struct hv_device *vmbus_device_create(const guid_t *type,
1987                                       const guid_t *instance,
1988                                       struct vmbus_channel *channel)
1989 {
1990         struct hv_device *child_device_obj;
1991
1992         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1993         if (!child_device_obj) {
1994                 pr_err("Unable to allocate device object for child device\n");
1995                 return NULL;
1996         }
1997
1998         child_device_obj->channel = channel;
1999         guid_copy(&child_device_obj->dev_type, type);
2000         guid_copy(&child_device_obj->dev_instance, instance);
2001         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
2002
2003         return child_device_obj;
2004 }
2005
2006 /*
2007  * vmbus_device_register - Register the child device
2008  */
2009 int vmbus_device_register(struct hv_device *child_device_obj)
2010 {
2011         struct kobject *kobj = &child_device_obj->device.kobj;
2012         int ret;
2013
2014         dev_set_name(&child_device_obj->device, "%pUl",
2015                      &child_device_obj->channel->offermsg.offer.if_instance);
2016
2017         child_device_obj->device.bus = &hv_bus;
2018         child_device_obj->device.parent = &hv_acpi_dev->dev;
2019         child_device_obj->device.release = vmbus_device_release;
2020
2021         /*
2022          * Register with the LDM. This will kick off the driver/device
2023          * binding...which will eventually call vmbus_match() and vmbus_probe()
2024          */
2025         ret = device_register(&child_device_obj->device);
2026         if (ret) {
2027                 pr_err("Unable to register child device\n");
2028                 return ret;
2029         }
2030
2031         child_device_obj->channels_kset = kset_create_and_add("channels",
2032                                                               NULL, kobj);
2033         if (!child_device_obj->channels_kset) {
2034                 ret = -ENOMEM;
2035                 goto err_dev_unregister;
2036         }
2037
2038         ret = vmbus_add_channel_kobj(child_device_obj,
2039                                      child_device_obj->channel);
2040         if (ret) {
2041                 pr_err("Unable to register primary channeln");
2042                 goto err_kset_unregister;
2043         }
2044         hv_debug_add_dev_dir(child_device_obj);
2045
2046         return 0;
2047
2048 err_kset_unregister:
2049         kset_unregister(child_device_obj->channels_kset);
2050
2051 err_dev_unregister:
2052         device_unregister(&child_device_obj->device);
2053         return ret;
2054 }
2055
2056 /*
2057  * vmbus_device_unregister - Remove the specified child device
2058  * from the vmbus.
2059  */
2060 void vmbus_device_unregister(struct hv_device *device_obj)
2061 {
2062         pr_debug("child device %s unregistered\n",
2063                 dev_name(&device_obj->device));
2064
2065         kset_unregister(device_obj->channels_kset);
2066
2067         /*
2068          * Kick off the process of unregistering the device.
2069          * This will call vmbus_remove() and eventually vmbus_device_release()
2070          */
2071         device_unregister(&device_obj->device);
2072 }
2073
2074
2075 /*
2076  * VMBUS is an acpi enumerated device. Get the information we
2077  * need from DSDT.
2078  */
2079 #define VTPM_BASE_ADDRESS 0xfed40000
2080 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
2081 {
2082         resource_size_t start = 0;
2083         resource_size_t end = 0;
2084         struct resource *new_res;
2085         struct resource **old_res = &hyperv_mmio;
2086         struct resource **prev_res = NULL;
2087         struct resource r;
2088
2089         switch (res->type) {
2090
2091         /*
2092          * "Address" descriptors are for bus windows. Ignore
2093          * "memory" descriptors, which are for registers on
2094          * devices.
2095          */
2096         case ACPI_RESOURCE_TYPE_ADDRESS32:
2097                 start = res->data.address32.address.minimum;
2098                 end = res->data.address32.address.maximum;
2099                 break;
2100
2101         case ACPI_RESOURCE_TYPE_ADDRESS64:
2102                 start = res->data.address64.address.minimum;
2103                 end = res->data.address64.address.maximum;
2104                 break;
2105
2106         /*
2107          * The IRQ information is needed only on ARM64, which Hyper-V
2108          * sets up in the extended format. IRQ information is present
2109          * on x86/x64 in the non-extended format but it is not used by
2110          * Linux. So don't bother checking for the non-extended format.
2111          */
2112         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
2113                 if (!acpi_dev_resource_interrupt(res, 0, &r)) {
2114                         pr_err("Unable to parse Hyper-V ACPI interrupt\n");
2115                         return AE_ERROR;
2116                 }
2117                 /* ARM64 INTID for VMbus */
2118                 vmbus_interrupt = res->data.extended_irq.interrupts[0];
2119                 /* Linux IRQ number */
2120                 vmbus_irq = r.start;
2121                 return AE_OK;
2122
2123         default:
2124                 /* Unused resource type */
2125                 return AE_OK;
2126
2127         }
2128         /*
2129          * Ignore ranges that are below 1MB, as they're not
2130          * necessary or useful here.
2131          */
2132         if (end < 0x100000)
2133                 return AE_OK;
2134
2135         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
2136         if (!new_res)
2137                 return AE_NO_MEMORY;
2138
2139         /* If this range overlaps the virtual TPM, truncate it. */
2140         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
2141                 end = VTPM_BASE_ADDRESS;
2142
2143         new_res->name = "hyperv mmio";
2144         new_res->flags = IORESOURCE_MEM;
2145         new_res->start = start;
2146         new_res->end = end;
2147
2148         /*
2149          * If two ranges are adjacent, merge them.
2150          */
2151         do {
2152                 if (!*old_res) {
2153                         *old_res = new_res;
2154                         break;
2155                 }
2156
2157                 if (((*old_res)->end + 1) == new_res->start) {
2158                         (*old_res)->end = new_res->end;
2159                         kfree(new_res);
2160                         break;
2161                 }
2162
2163                 if ((*old_res)->start == new_res->end + 1) {
2164                         (*old_res)->start = new_res->start;
2165                         kfree(new_res);
2166                         break;
2167                 }
2168
2169                 if ((*old_res)->start > new_res->end) {
2170                         new_res->sibling = *old_res;
2171                         if (prev_res)
2172                                 (*prev_res)->sibling = new_res;
2173                         *old_res = new_res;
2174                         break;
2175                 }
2176
2177                 prev_res = old_res;
2178                 old_res = &(*old_res)->sibling;
2179
2180         } while (1);
2181
2182         return AE_OK;
2183 }
2184
2185 static int vmbus_acpi_remove(struct acpi_device *device)
2186 {
2187         struct resource *cur_res;
2188         struct resource *next_res;
2189
2190         if (hyperv_mmio) {
2191                 if (fb_mmio) {
2192                         __release_region(hyperv_mmio, fb_mmio->start,
2193                                          resource_size(fb_mmio));
2194                         fb_mmio = NULL;
2195                 }
2196
2197                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
2198                         next_res = cur_res->sibling;
2199                         kfree(cur_res);
2200                 }
2201         }
2202
2203         return 0;
2204 }
2205
2206 static void vmbus_reserve_fb(void)
2207 {
2208         int size;
2209         /*
2210          * Make a claim for the frame buffer in the resource tree under the
2211          * first node, which will be the one below 4GB.  The length seems to
2212          * be underreported, particularly in a Generation 1 VM.  So start out
2213          * reserving a larger area and make it smaller until it succeeds.
2214          */
2215
2216         if (screen_info.lfb_base) {
2217                 if (efi_enabled(EFI_BOOT))
2218                         size = max_t(__u32, screen_info.lfb_size, 0x800000);
2219                 else
2220                         size = max_t(__u32, screen_info.lfb_size, 0x4000000);
2221
2222                 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
2223                         fb_mmio = __request_region(hyperv_mmio,
2224                                                    screen_info.lfb_base, size,
2225                                                    fb_mmio_name, 0);
2226                 }
2227         }
2228 }
2229
2230 /**
2231  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
2232  * @new:                If successful, supplied a pointer to the
2233  *                      allocated MMIO space.
2234  * @device_obj:         Identifies the caller
2235  * @min:                Minimum guest physical address of the
2236  *                      allocation
2237  * @max:                Maximum guest physical address
2238  * @size:               Size of the range to be allocated
2239  * @align:              Alignment of the range to be allocated
2240  * @fb_overlap_ok:      Whether this allocation can be allowed
2241  *                      to overlap the video frame buffer.
2242  *
2243  * This function walks the resources granted to VMBus by the
2244  * _CRS object in the ACPI namespace underneath the parent
2245  * "bridge" whether that's a root PCI bus in the Generation 1
2246  * case or a Module Device in the Generation 2 case.  It then
2247  * attempts to allocate from the global MMIO pool in a way that
2248  * matches the constraints supplied in these parameters and by
2249  * that _CRS.
2250  *
2251  * Return: 0 on success, -errno on failure
2252  */
2253 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2254                         resource_size_t min, resource_size_t max,
2255                         resource_size_t size, resource_size_t align,
2256                         bool fb_overlap_ok)
2257 {
2258         struct resource *iter, *shadow;
2259         resource_size_t range_min, range_max, start;
2260         const char *dev_n = dev_name(&device_obj->device);
2261         int retval;
2262
2263         retval = -ENXIO;
2264         mutex_lock(&hyperv_mmio_lock);
2265
2266         /*
2267          * If overlaps with frame buffers are allowed, then first attempt to
2268          * make the allocation from within the reserved region.  Because it
2269          * is already reserved, no shadow allocation is necessary.
2270          */
2271         if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2272             !(max < fb_mmio->start)) {
2273
2274                 range_min = fb_mmio->start;
2275                 range_max = fb_mmio->end;
2276                 start = (range_min + align - 1) & ~(align - 1);
2277                 for (; start + size - 1 <= range_max; start += align) {
2278                         *new = request_mem_region_exclusive(start, size, dev_n);
2279                         if (*new) {
2280                                 retval = 0;
2281                                 goto exit;
2282                         }
2283                 }
2284         }
2285
2286         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2287                 if ((iter->start >= max) || (iter->end <= min))
2288                         continue;
2289
2290                 range_min = iter->start;
2291                 range_max = iter->end;
2292                 start = (range_min + align - 1) & ~(align - 1);
2293                 for (; start + size - 1 <= range_max; start += align) {
2294                         shadow = __request_region(iter, start, size, NULL,
2295                                                   IORESOURCE_BUSY);
2296                         if (!shadow)
2297                                 continue;
2298
2299                         *new = request_mem_region_exclusive(start, size, dev_n);
2300                         if (*new) {
2301                                 shadow->name = (char *)*new;
2302                                 retval = 0;
2303                                 goto exit;
2304                         }
2305
2306                         __release_region(iter, start, size);
2307                 }
2308         }
2309
2310 exit:
2311         mutex_unlock(&hyperv_mmio_lock);
2312         return retval;
2313 }
2314 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2315
2316 /**
2317  * vmbus_free_mmio() - Free a memory-mapped I/O range.
2318  * @start:              Base address of region to release.
2319  * @size:               Size of the range to be allocated
2320  *
2321  * This function releases anything requested by
2322  * vmbus_mmio_allocate().
2323  */
2324 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2325 {
2326         struct resource *iter;
2327
2328         mutex_lock(&hyperv_mmio_lock);
2329         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2330                 if ((iter->start >= start + size) || (iter->end <= start))
2331                         continue;
2332
2333                 __release_region(iter, start, size);
2334         }
2335         release_mem_region(start, size);
2336         mutex_unlock(&hyperv_mmio_lock);
2337
2338 }
2339 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2340
2341 static int vmbus_acpi_add(struct acpi_device *device)
2342 {
2343         acpi_status result;
2344         int ret_val = -ENODEV;
2345         struct acpi_device *ancestor;
2346
2347         hv_acpi_dev = device;
2348
2349         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2350                                         vmbus_walk_resources, NULL);
2351
2352         if (ACPI_FAILURE(result))
2353                 goto acpi_walk_err;
2354         /*
2355          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2356          * firmware) is the VMOD that has the mmio ranges. Get that.
2357          */
2358         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2359                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2360                                              vmbus_walk_resources, NULL);
2361
2362                 if (ACPI_FAILURE(result))
2363                         continue;
2364                 if (hyperv_mmio) {
2365                         vmbus_reserve_fb();
2366                         break;
2367                 }
2368         }
2369         ret_val = 0;
2370
2371 acpi_walk_err:
2372         complete(&probe_event);
2373         if (ret_val)
2374                 vmbus_acpi_remove(device);
2375         return ret_val;
2376 }
2377
2378 #ifdef CONFIG_PM_SLEEP
2379 static int vmbus_bus_suspend(struct device *dev)
2380 {
2381         struct vmbus_channel *channel, *sc;
2382
2383         while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
2384                 /*
2385                  * We wait here until the completion of any channel
2386                  * offers that are currently in progress.
2387                  */
2388                 usleep_range(1000, 2000);
2389         }
2390
2391         mutex_lock(&vmbus_connection.channel_mutex);
2392         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2393                 if (!is_hvsock_channel(channel))
2394                         continue;
2395
2396                 vmbus_force_channel_rescinded(channel);
2397         }
2398         mutex_unlock(&vmbus_connection.channel_mutex);
2399
2400         /*
2401          * Wait until all the sub-channels and hv_sock channels have been
2402          * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2403          * they would conflict with the new sub-channels that will be created
2404          * in the resume path. hv_sock channels should also be destroyed, but
2405          * a hv_sock channel of an established hv_sock connection can not be
2406          * really destroyed since it may still be referenced by the userspace
2407          * application, so we just force the hv_sock channel to be rescinded
2408          * by vmbus_force_channel_rescinded(), and the userspace application
2409          * will thoroughly destroy the channel after hibernation.
2410          *
2411          * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2412          * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2413          */
2414         if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2415                 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2416
2417         if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) {
2418                 pr_err("Can not suspend due to a previous failed resuming\n");
2419                 return -EBUSY;
2420         }
2421
2422         mutex_lock(&vmbus_connection.channel_mutex);
2423
2424         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2425                 /*
2426                  * Remove the channel from the array of channels and invalidate
2427                  * the channel's relid.  Upon resume, vmbus_onoffer() will fix
2428                  * up the relid (and other fields, if necessary) and add the
2429                  * channel back to the array.
2430                  */
2431                 vmbus_channel_unmap_relid(channel);
2432                 channel->offermsg.child_relid = INVALID_RELID;
2433
2434                 if (is_hvsock_channel(channel)) {
2435                         if (!channel->rescind) {
2436                                 pr_err("hv_sock channel not rescinded!\n");
2437                                 WARN_ON_ONCE(1);
2438                         }
2439                         continue;
2440                 }
2441
2442                 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2443                         pr_err("Sub-channel not deleted!\n");
2444                         WARN_ON_ONCE(1);
2445                 }
2446
2447                 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2448         }
2449
2450         mutex_unlock(&vmbus_connection.channel_mutex);
2451
2452         vmbus_initiate_unload(false);
2453
2454         /* Reset the event for the next resume. */
2455         reinit_completion(&vmbus_connection.ready_for_resume_event);
2456
2457         return 0;
2458 }
2459
2460 static int vmbus_bus_resume(struct device *dev)
2461 {
2462         struct vmbus_channel_msginfo *msginfo;
2463         size_t msgsize;
2464         int ret;
2465
2466         /*
2467          * We only use the 'vmbus_proto_version', which was in use before
2468          * hibernation, to re-negotiate with the host.
2469          */
2470         if (!vmbus_proto_version) {
2471                 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2472                 return -EINVAL;
2473         }
2474
2475         msgsize = sizeof(*msginfo) +
2476                   sizeof(struct vmbus_channel_initiate_contact);
2477
2478         msginfo = kzalloc(msgsize, GFP_KERNEL);
2479
2480         if (msginfo == NULL)
2481                 return -ENOMEM;
2482
2483         ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2484
2485         kfree(msginfo);
2486
2487         if (ret != 0)
2488                 return ret;
2489
2490         WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2491
2492         vmbus_request_offers();
2493
2494         if (wait_for_completion_timeout(
2495                 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0)
2496                 pr_err("Some vmbus device is missing after suspending?\n");
2497
2498         /* Reset the event for the next suspend. */
2499         reinit_completion(&vmbus_connection.ready_for_suspend_event);
2500
2501         return 0;
2502 }
2503 #else
2504 #define vmbus_bus_suspend NULL
2505 #define vmbus_bus_resume NULL
2506 #endif /* CONFIG_PM_SLEEP */
2507
2508 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2509         {"VMBUS", 0},
2510         {"VMBus", 0},
2511         {"", 0},
2512 };
2513 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2514
2515 /*
2516  * Note: we must use the "no_irq" ops, otherwise hibernation can not work with
2517  * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
2518  * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
2519  * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2520  * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2521  * resume callback must also run via the "noirq" ops.
2522  *
2523  * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
2524  * earlier in this file before vmbus_pm.
2525  */
2526
2527 static const struct dev_pm_ops vmbus_bus_pm = {
2528         .suspend_noirq  = NULL,
2529         .resume_noirq   = NULL,
2530         .freeze_noirq   = vmbus_bus_suspend,
2531         .thaw_noirq     = vmbus_bus_resume,
2532         .poweroff_noirq = vmbus_bus_suspend,
2533         .restore_noirq  = vmbus_bus_resume
2534 };
2535
2536 static struct acpi_driver vmbus_acpi_driver = {
2537         .name = "vmbus",
2538         .ids = vmbus_acpi_device_ids,
2539         .ops = {
2540                 .add = vmbus_acpi_add,
2541                 .remove = vmbus_acpi_remove,
2542         },
2543         .drv.pm = &vmbus_bus_pm,
2544 };
2545
2546 static void hv_kexec_handler(void)
2547 {
2548         hv_stimer_global_cleanup();
2549         vmbus_initiate_unload(false);
2550         /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2551         mb();
2552         cpuhp_remove_state(hyperv_cpuhp_online);
2553         hyperv_cleanup();
2554 };
2555
2556 static void hv_crash_handler(struct pt_regs *regs)
2557 {
2558         int cpu;
2559
2560         vmbus_initiate_unload(true);
2561         /*
2562          * In crash handler we can't schedule synic cleanup for all CPUs,
2563          * doing the cleanup for current CPU only. This should be sufficient
2564          * for kdump.
2565          */
2566         cpu = smp_processor_id();
2567         hv_stimer_cleanup(cpu);
2568         hv_synic_disable_regs(cpu);
2569         hyperv_cleanup();
2570 };
2571
2572 static int hv_synic_suspend(void)
2573 {
2574         /*
2575          * When we reach here, all the non-boot CPUs have been offlined.
2576          * If we're in a legacy configuration where stimer Direct Mode is
2577          * not enabled, the stimers on the non-boot CPUs have been unbound
2578          * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2579          * hv_stimer_cleanup() -> clockevents_unbind_device().
2580          *
2581          * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2582          * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2583          * 1) it's unnecessary as interrupts remain disabled between
2584          * syscore_suspend() and syscore_resume(): see create_image() and
2585          * resume_target_kernel()
2586          * 2) the stimer on CPU0 is automatically disabled later by
2587          * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2588          * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2589          * 3) a warning would be triggered if we call
2590          * clockevents_unbind_device(), which may sleep, in an
2591          * interrupts-disabled context.
2592          */
2593
2594         hv_synic_disable_regs(0);
2595
2596         return 0;
2597 }
2598
2599 static void hv_synic_resume(void)
2600 {
2601         hv_synic_enable_regs(0);
2602
2603         /*
2604          * Note: we don't need to call hv_stimer_init(0), because the timer
2605          * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2606          * automatically re-enabled in timekeeping_resume().
2607          */
2608 }
2609
2610 /* The callbacks run only on CPU0, with irqs_disabled. */
2611 static struct syscore_ops hv_synic_syscore_ops = {
2612         .suspend = hv_synic_suspend,
2613         .resume = hv_synic_resume,
2614 };
2615
2616 static int __init hv_acpi_init(void)
2617 {
2618         int ret, t;
2619
2620         if (!hv_is_hyperv_initialized())
2621                 return -ENODEV;
2622
2623         init_completion(&probe_event);
2624
2625         /*
2626          * Get ACPI resources first.
2627          */
2628         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2629
2630         if (ret)
2631                 return ret;
2632
2633         t = wait_for_completion_timeout(&probe_event, 5*HZ);
2634         if (t == 0) {
2635                 ret = -ETIMEDOUT;
2636                 goto cleanup;
2637         }
2638         hv_debug_init();
2639
2640         ret = vmbus_bus_init();
2641         if (ret)
2642                 goto cleanup;
2643
2644         hv_setup_kexec_handler(hv_kexec_handler);
2645         hv_setup_crash_handler(hv_crash_handler);
2646
2647         register_syscore_ops(&hv_synic_syscore_ops);
2648
2649         return 0;
2650
2651 cleanup:
2652         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2653         hv_acpi_dev = NULL;
2654         return ret;
2655 }
2656
2657 static void __exit vmbus_exit(void)
2658 {
2659         int cpu;
2660
2661         unregister_syscore_ops(&hv_synic_syscore_ops);
2662
2663         hv_remove_kexec_handler();
2664         hv_remove_crash_handler();
2665         vmbus_connection.conn_state = DISCONNECTED;
2666         hv_stimer_global_cleanup();
2667         vmbus_disconnect();
2668         hv_remove_vmbus_irq();
2669         for_each_online_cpu(cpu) {
2670                 struct hv_per_cpu_context *hv_cpu
2671                         = per_cpu_ptr(hv_context.cpu_context, cpu);
2672
2673                 tasklet_kill(&hv_cpu->msg_dpc);
2674         }
2675         hv_debug_rm_all_dir();
2676
2677         vmbus_free_channels();
2678         kfree(vmbus_connection.channels);
2679
2680         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2681                 kmsg_dump_unregister(&hv_kmsg_dumper);
2682                 unregister_die_notifier(&hyperv_die_block);
2683                 atomic_notifier_chain_unregister(&panic_notifier_list,
2684                                                  &hyperv_panic_block);
2685         }
2686
2687         free_page((unsigned long)hv_panic_page);
2688         unregister_sysctl_table(hv_ctl_table_hdr);
2689         hv_ctl_table_hdr = NULL;
2690         bus_unregister(&hv_bus);
2691
2692         cpuhp_remove_state(hyperv_cpuhp_online);
2693         hv_synic_free();
2694         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2695 }
2696
2697
2698 MODULE_LICENSE("GPL");
2699 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2700
2701 subsys_initcall(hv_acpi_init);
2702 module_exit(vmbus_exit);