drivers/hv/vmbus_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *   K. Y. Srinivasan <kys@microsoft.com>
  21  *
  22  */
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/device.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/sysctl.h>
  30 #include <linux/slab.h>
  31 #include <linux/acpi.h>
  32 #include <linux/completion.h>
  33 #include <linux/hyperv.h>
  34 #include <linux/kernel_stat.h>
  35 #include <linux/clockchips.h>
  36 #include <linux/cpu.h>
  37 #include <linux/sched/task_stack.h>
  38
  39 #include <asm/hyperv.h>
  40 #include <asm/hypervisor.h>
  41 #include <asm/mshyperv.h>
  42 #include <linux/notifier.h>
  43 #include <linux/ptrace.h>
  44 #include <linux/screen_info.h>
  45 #include <linux/kdebug.h>
  46 #include <linux/efi.h>
  47 #include <linux/random.h>
  48 #include "hyperv_vmbus.h"
  49
  50 struct vmbus_dynid {
  51         struct list_head node;
  52         struct hv_vmbus_device_id id;
  53 };
  54
  55 static struct acpi_device  *hv_acpi_dev;
  56
  57 static struct completion probe_event;
  58
  59 static int hyperv_cpuhp_online;
  60
  61 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
  62                               void *args)
  63 {
  64         struct pt_regs *regs;
  65
  66         regs = current_pt_regs();
  67
  68         hyperv_report_panic(regs);
  69         return NOTIFY_DONE;
  70 }
  71
  72 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
  73                             void *args)
  74 {
  75         struct die_args *die = (struct die_args *)args;
  76         struct pt_regs *regs = die->regs;
  77
  78         hyperv_report_panic(regs);
  79         return NOTIFY_DONE;
  80 }
  81
  82 static struct notifier_block hyperv_die_block = {
  83         .notifier_call = hyperv_die_event,
  84 };
  85 static struct notifier_block hyperv_panic_block = {
  86         .notifier_call = hyperv_panic_event,
  87 };
  88
  89 static const char *fb_mmio_name = "fb_range";
  90 static struct resource *fb_mmio;
  91 static struct resource *hyperv_mmio;
  92 static DEFINE_SEMAPHORE(hyperv_mmio_lock);
  93
  94 static int vmbus_exists(void)
  95 {
  96         if (hv_acpi_dev == NULL)
  97                 return -ENODEV;
  98
  99         return 0;
 100 }
 101
 102 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 103 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 104 {
 105         int i;
 106         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 107                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 108 }
 109
 110 static u8 channel_monitor_group(struct vmbus_channel *channel)
 111 {
 112         return (u8)channel->offermsg.monitorid / 32;
 113 }
 114
 115 static u8 channel_monitor_offset(struct vmbus_channel *channel)
 116 {
 117         return (u8)channel->offermsg.monitorid % 32;
 118 }
 119
 120 static u32 channel_pending(struct vmbus_channel *channel,
 121                            struct hv_monitor_page *monitor_page)
 122 {
 123         u8 monitor_group = channel_monitor_group(channel);
 124         return monitor_page->trigger_group[monitor_group].pending;
 125 }
 126
 127 static u32 channel_latency(struct vmbus_channel *channel,
 128                            struct hv_monitor_page *monitor_page)
 129 {
 130         u8 monitor_group = channel_monitor_group(channel);
 131         u8 monitor_offset = channel_monitor_offset(channel);
 132         return monitor_page->latency[monitor_group][monitor_offset];
 133 }
 134
 135 static u32 channel_conn_id(struct vmbus_channel *channel,
 136                            struct hv_monitor_page *monitor_page)
 137 {
 138         u8 monitor_group = channel_monitor_group(channel);
 139         u8 monitor_offset = channel_monitor_offset(channel);
 140         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 141 }
 142
 143 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 144                        char *buf)
 145 {
 146         struct hv_device *hv_dev = device_to_hv_device(dev);
 147
 148         if (!hv_dev->channel)
 149                 return -ENODEV;
 150         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 151 }
 152 static DEVICE_ATTR_RO(id);
 153
 154 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 155                           char *buf)
 156 {
 157         struct hv_device *hv_dev = device_to_hv_device(dev);
 158
 159         if (!hv_dev->channel)
 160                 return -ENODEV;
 161         return sprintf(buf, "%d\n", hv_dev->channel->state);
 162 }
 163 static DEVICE_ATTR_RO(state);
 164
 165 static ssize_t monitor_id_show(struct device *dev,
 166                                struct device_attribute *dev_attr, char *buf)
 167 {
 168         struct hv_device *hv_dev = device_to_hv_device(dev);
 169
 170         if (!hv_dev->channel)
 171                 return -ENODEV;
 172         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
 173 }
 174 static DEVICE_ATTR_RO(monitor_id);
 175
 176 static ssize_t class_id_show(struct device *dev,
 177                                struct device_attribute *dev_attr, char *buf)
 178 {
 179         struct hv_device *hv_dev = device_to_hv_device(dev);
 180
 181         if (!hv_dev->channel)
 182                 return -ENODEV;
 183         return sprintf(buf, "{%pUl}\n",
 184                        hv_dev->channel->offermsg.offer.if_type.b);
 185 }
 186 static DEVICE_ATTR_RO(class_id);
 187
 188 static ssize_t device_id_show(struct device *dev,
 189                               struct device_attribute *dev_attr, char *buf)
 190 {
 191         struct hv_device *hv_dev = device_to_hv_device(dev);
 192
 193         if (!hv_dev->channel)
 194                 return -ENODEV;
 195         return sprintf(buf, "{%pUl}\n",
 196                        hv_dev->channel->offermsg.offer.if_instance.b);
 197 }
 198 static DEVICE_ATTR_RO(device_id);
 199
 200 static ssize_t modalias_show(struct device *dev,
 201                              struct device_attribute *dev_attr, char *buf)
 202 {
 203         struct hv_device *hv_dev = device_to_hv_device(dev);
 204         char alias_name[VMBUS_ALIAS_LEN + 1];
 205
 206         print_alias_name(hv_dev, alias_name);
 207         return sprintf(buf, "vmbus:%s\n", alias_name);
 208 }
 209 static DEVICE_ATTR_RO(modalias);
 210
 211 static ssize_t server_monitor_pending_show(struct device *dev,
 212                                            struct device_attribute *dev_attr,
 213                                            char *buf)
 214 {
 215         struct hv_device *hv_dev = device_to_hv_device(dev);
 216
 217         if (!hv_dev->channel)
 218                 return -ENODEV;
 219         return sprintf(buf, "%d\n",
 220                        channel_pending(hv_dev->channel,
 221                                        vmbus_connection.monitor_pages[1]));
 222 }
 223 static DEVICE_ATTR_RO(server_monitor_pending);
 224
 225 static ssize_t client_monitor_pending_show(struct device *dev,
 226                                            struct device_attribute *dev_attr,
 227                                            char *buf)
 228 {
 229         struct hv_device *hv_dev = device_to_hv_device(dev);
 230
 231         if (!hv_dev->channel)
 232                 return -ENODEV;
 233         return sprintf(buf, "%d\n",
 234                        channel_pending(hv_dev->channel,
 235                                        vmbus_connection.monitor_pages[1]));
 236 }
 237 static DEVICE_ATTR_RO(client_monitor_pending);
 238
 239 static ssize_t server_monitor_latency_show(struct device *dev,
 240                                            struct device_attribute *dev_attr,
 241                                            char *buf)
 242 {
 243         struct hv_device *hv_dev = device_to_hv_device(dev);
 244
 245         if (!hv_dev->channel)
 246                 return -ENODEV;
 247         return sprintf(buf, "%d\n",
 248                        channel_latency(hv_dev->channel,
 249                                        vmbus_connection.monitor_pages[0]));
 250 }
 251 static DEVICE_ATTR_RO(server_monitor_latency);
 252
 253 static ssize_t client_monitor_latency_show(struct device *dev,
 254                                            struct device_attribute *dev_attr,
 255                                            char *buf)
 256 {
 257         struct hv_device *hv_dev = device_to_hv_device(dev);
 258
 259         if (!hv_dev->channel)
 260                 return -ENODEV;
 261         return sprintf(buf, "%d\n",
 262                        channel_latency(hv_dev->channel,
 263                                        vmbus_connection.monitor_pages[1]));
 264 }
 265 static DEVICE_ATTR_RO(client_monitor_latency);
 266
 267 static ssize_t server_monitor_conn_id_show(struct device *dev,
 268                                            struct device_attribute *dev_attr,
 269                                            char *buf)
 270 {
 271         struct hv_device *hv_dev = device_to_hv_device(dev);
 272
 273         if (!hv_dev->channel)
 274                 return -ENODEV;
 275         return sprintf(buf, "%d\n",
 276                        channel_conn_id(hv_dev->channel,
 277                                        vmbus_connection.monitor_pages[0]));
 278 }
 279 static DEVICE_ATTR_RO(server_monitor_conn_id);
 280
 281 static ssize_t client_monitor_conn_id_show(struct device *dev,
 282                                            struct device_attribute *dev_attr,
 283                                            char *buf)
 284 {
 285         struct hv_device *hv_dev = device_to_hv_device(dev);
 286
 287         if (!hv_dev->channel)
 288                 return -ENODEV;
 289         return sprintf(buf, "%d\n",
 290                        channel_conn_id(hv_dev->channel,
 291                                        vmbus_connection.monitor_pages[1]));
 292 }
 293 static DEVICE_ATTR_RO(client_monitor_conn_id);
 294
 295 static ssize_t out_intr_mask_show(struct device *dev,
 296                                   struct device_attribute *dev_attr, char *buf)
 297 {
 298         struct hv_device *hv_dev = device_to_hv_device(dev);
 299         struct hv_ring_buffer_debug_info outbound;
 300
 301         if (!hv_dev->channel)
 302                 return -ENODEV;
 303         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 304         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 305 }
 306 static DEVICE_ATTR_RO(out_intr_mask);
 307
 308 static ssize_t out_read_index_show(struct device *dev,
 309                                    struct device_attribute *dev_attr, char *buf)
 310 {
 311         struct hv_device *hv_dev = device_to_hv_device(dev);
 312         struct hv_ring_buffer_debug_info outbound;
 313
 314         if (!hv_dev->channel)
 315                 return -ENODEV;
 316         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 317         return sprintf(buf, "%d\n", outbound.current_read_index);
 318 }
 319 static DEVICE_ATTR_RO(out_read_index);
 320
 321 static ssize_t out_write_index_show(struct device *dev,
 322                                     struct device_attribute *dev_attr,
 323                                     char *buf)
 324 {
 325         struct hv_device *hv_dev = device_to_hv_device(dev);
 326         struct hv_ring_buffer_debug_info outbound;
 327
 328         if (!hv_dev->channel)
 329                 return -ENODEV;
 330         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 331         return sprintf(buf, "%d\n", outbound.current_write_index);
 332 }
 333 static DEVICE_ATTR_RO(out_write_index);
 334
 335 static ssize_t out_read_bytes_avail_show(struct device *dev,
 336                                          struct device_attribute *dev_attr,
 337                                          char *buf)
 338 {
 339         struct hv_device *hv_dev = device_to_hv_device(dev);
 340         struct hv_ring_buffer_debug_info outbound;
 341
 342         if (!hv_dev->channel)
 343                 return -ENODEV;
 344         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 345         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 346 }
 347 static DEVICE_ATTR_RO(out_read_bytes_avail);
 348
 349 static ssize_t out_write_bytes_avail_show(struct device *dev,
 350                                           struct device_attribute *dev_attr,
 351                                           char *buf)
 352 {
 353         struct hv_device *hv_dev = device_to_hv_device(dev);
 354         struct hv_ring_buffer_debug_info outbound;
 355
 356         if (!hv_dev->channel)
 357                 return -ENODEV;
 358         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 359         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 360 }
 361 static DEVICE_ATTR_RO(out_write_bytes_avail);
 362
 363 static ssize_t in_intr_mask_show(struct device *dev,
 364                                  struct device_attribute *dev_attr, char *buf)
 365 {
 366         struct hv_device *hv_dev = device_to_hv_device(dev);
 367         struct hv_ring_buffer_debug_info inbound;
 368
 369         if (!hv_dev->channel)
 370                 return -ENODEV;
 371         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 372         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 373 }
 374 static DEVICE_ATTR_RO(in_intr_mask);
 375
 376 static ssize_t in_read_index_show(struct device *dev,
 377                                   struct device_attribute *dev_attr, char *buf)
 378 {
 379         struct hv_device *hv_dev = device_to_hv_device(dev);
 380         struct hv_ring_buffer_debug_info inbound;
 381
 382         if (!hv_dev->channel)
 383                 return -ENODEV;
 384         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 385         return sprintf(buf, "%d\n", inbound.current_read_index);
 386 }
 387 static DEVICE_ATTR_RO(in_read_index);
 388
 389 static ssize_t in_write_index_show(struct device *dev,
 390                                    struct device_attribute *dev_attr, char *buf)
 391 {
 392         struct hv_device *hv_dev = device_to_hv_device(dev);
 393         struct hv_ring_buffer_debug_info inbound;
 394
 395         if (!hv_dev->channel)
 396                 return -ENODEV;
 397         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 398         return sprintf(buf, "%d\n", inbound.current_write_index);
 399 }
 400 static DEVICE_ATTR_RO(in_write_index);
 401
 402 static ssize_t in_read_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 inbound;
 408
 409         if (!hv_dev->channel)
 410                 return -ENODEV;
 411         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 412         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 413 }
 414 static DEVICE_ATTR_RO(in_read_bytes_avail);
 415
 416 static ssize_t in_write_bytes_avail_show(struct device *dev,
 417                                          struct device_attribute *dev_attr,
 418                                          char *buf)
 419 {
 420         struct hv_device *hv_dev = device_to_hv_device(dev);
 421         struct hv_ring_buffer_debug_info inbound;
 422
 423         if (!hv_dev->channel)
 424                 return -ENODEV;
 425         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 426         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 427 }
 428 static DEVICE_ATTR_RO(in_write_bytes_avail);
 429
 430 static ssize_t channel_vp_mapping_show(struct device *dev,
 431                                        struct device_attribute *dev_attr,
 432                                        char *buf)
 433 {
 434         struct hv_device *hv_dev = device_to_hv_device(dev);
 435         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 436         unsigned long flags;
 437         int buf_size = PAGE_SIZE, n_written, tot_written;
 438         struct list_head *cur;
 439
 440         if (!channel)
 441                 return -ENODEV;
 442
 443         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 444                 channel->offermsg.child_relid, channel->target_cpu);
 445
 446         spin_lock_irqsave(&channel->lock, flags);
 447
 448         list_for_each(cur, &channel->sc_list) {
 449                 if (tot_written >= buf_size - 1)
 450                         break;
 451
 452                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 453                 n_written = scnprintf(buf + tot_written,
 454                                      buf_size - tot_written,
 455                                      "%u:%u\n",
 456                                      cur_sc->offermsg.child_relid,
 457                                      cur_sc->target_cpu);
 458                 tot_written += n_written;
 459         }
 460
 461         spin_unlock_irqrestore(&channel->lock, flags);
 462
 463         return tot_written;
 464 }
 465 static DEVICE_ATTR_RO(channel_vp_mapping);
 466
 467 static ssize_t vendor_show(struct device *dev,
 468                            struct device_attribute *dev_attr,
 469                            char *buf)
 470 {
 471         struct hv_device *hv_dev = device_to_hv_device(dev);
 472         return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
 473 }
 474 static DEVICE_ATTR_RO(vendor);
 475
 476 static ssize_t device_show(struct device *dev,
 477                            struct device_attribute *dev_attr,
 478                            char *buf)
 479 {
 480         struct hv_device *hv_dev = device_to_hv_device(dev);
 481         return sprintf(buf, "0x%x\n", hv_dev->device_id);
 482 }
 483 static DEVICE_ATTR_RO(device);
 484
 485 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 486 static struct attribute *vmbus_dev_attrs[] = {
 487         &dev_attr_id.attr,
 488         &dev_attr_state.attr,
 489         &dev_attr_monitor_id.attr,
 490         &dev_attr_class_id.attr,
 491         &dev_attr_device_id.attr,
 492         &dev_attr_modalias.attr,
 493         &dev_attr_server_monitor_pending.attr,
 494         &dev_attr_client_monitor_pending.attr,
 495         &dev_attr_server_monitor_latency.attr,
 496         &dev_attr_client_monitor_latency.attr,
 497         &dev_attr_server_monitor_conn_id.attr,
 498         &dev_attr_client_monitor_conn_id.attr,
 499         &dev_attr_out_intr_mask.attr,
 500         &dev_attr_out_read_index.attr,
 501         &dev_attr_out_write_index.attr,
 502         &dev_attr_out_read_bytes_avail.attr,
 503         &dev_attr_out_write_bytes_avail.attr,
 504         &dev_attr_in_intr_mask.attr,
 505         &dev_attr_in_read_index.attr,
 506         &dev_attr_in_write_index.attr,
 507         &dev_attr_in_read_bytes_avail.attr,
 508         &dev_attr_in_write_bytes_avail.attr,
 509         &dev_attr_channel_vp_mapping.attr,
 510         &dev_attr_vendor.attr,
 511         &dev_attr_device.attr,
 512         NULL,
 513 };
 514 ATTRIBUTE_GROUPS(vmbus_dev);
 515
 516 /*
 517  * vmbus_uevent - add uevent for our device
 518  *
 519  * This routine is invoked when a device is added or removed on the vmbus to
 520  * generate a uevent to udev in the userspace. The udev will then look at its
 521  * rule and the uevent generated here to load the appropriate driver
 522  *
 523  * The alias string will be of the form vmbus:guid where guid is the string
 524  * representation of the device guid (each byte of the guid will be
 525  * represented with two hex characters.
 526  */
 527 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 528 {
 529         struct hv_device *dev = device_to_hv_device(device);
 530         int ret;
 531         char alias_name[VMBUS_ALIAS_LEN + 1];
 532
 533         print_alias_name(dev, alias_name);
 534         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 535         return ret;
 536 }
 537
 538 static const uuid_le null_guid;
 539
 540 static inline bool is_null_guid(const uuid_le *guid)
 541 {
 542         if (uuid_le_cmp(*guid, null_guid))
 543                 return false;
 544         return true;
 545 }
 546
 547 /*
 548  * Return a matching hv_vmbus_device_id pointer.
 549  * If there is no match, return NULL.
 550  */
 551 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
 552                                         const uuid_le *guid)
 553 {
 554         const struct hv_vmbus_device_id *id = NULL;
 555         struct vmbus_dynid *dynid;
 556
 557         /* Look at the dynamic ids first, before the static ones */
 558         spin_lock(&drv->dynids.lock);
 559         list_for_each_entry(dynid, &drv->dynids.list, node) {
 560                 if (!uuid_le_cmp(dynid->id.guid, *guid)) {
 561                         id = &dynid->id;
 562                         break;
 563                 }
 564         }
 565         spin_unlock(&drv->dynids.lock);
 566
 567         if (id)
 568                 return id;
 569
 570         id = drv->id_table;
 571         if (id == NULL)
 572                 return NULL; /* empty device table */
 573
 574         for (; !is_null_guid(&id->guid); id++)
 575                 if (!uuid_le_cmp(id->guid, *guid))
 576                         return id;
 577
 578         return NULL;
 579 }
 580
 581 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
 582 static int vmbus_add_dynid(struct hv_driver *drv, uuid_le *guid)
 583 {
 584         struct vmbus_dynid *dynid;
 585
 586         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
 587         if (!dynid)
 588                 return -ENOMEM;
 589
 590         dynid->id.guid = *guid;
 591
 592         spin_lock(&drv->dynids.lock);
 593         list_add_tail(&dynid->node, &drv->dynids.list);
 594         spin_unlock(&drv->dynids.lock);
 595
 596         return driver_attach(&drv->driver);
 597 }
 598
 599 static void vmbus_free_dynids(struct hv_driver *drv)
 600 {
 601         struct vmbus_dynid *dynid, *n;
 602
 603         spin_lock(&drv->dynids.lock);
 604         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 605                 list_del(&dynid->node);
 606                 kfree(dynid);
 607         }
 608         spin_unlock(&drv->dynids.lock);
 609 }
 610
 611 /* Parse string of form: 1b4e28ba-2fa1-11d2-883f-b9a761bde3f */
 612 static int get_uuid_le(const char *str, uuid_le *uu)
 613 {
 614         unsigned int b[16];
 615         int i;
 616
 617         if (strlen(str) < 37)
 618                 return -1;
 619
 620         for (i = 0; i < 36; i++) {
 621                 switch (i) {
 622                 case 8: case 13: case 18: case 23:
 623                         if (str[i] != '-')
 624                                 return -1;
 625                         break;
 626                 default:
 627                         if (!isxdigit(str[i]))
 628                                 return -1;
 629                 }
 630         }
 631
 632         /* unparse little endian output byte order */
 633         if (sscanf(str,
 634                    "%2x%2x%2x%2x-%2x%2x-%2x%2x-%2x%2x-%2x%2x%2x%2x%2x%2x",
 635                    &b[3], &b[2], &b[1], &b[0],
 636                    &b[5], &b[4], &b[7], &b[6], &b[8], &b[9],
 637                    &b[10], &b[11], &b[12], &b[13], &b[14], &b[15]) != 16)
 638                 return -1;
 639
 640         for (i = 0; i < 16; i++)
 641                 uu->b[i] = b[i];
 642         return 0;
 643 }
 644
 645 /*
 646  * store_new_id - sysfs frontend to vmbus_add_dynid()
 647  *
 648  * Allow GUIDs to be added to an existing driver via sysfs.
 649  */
 650 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
 651                             size_t count)
 652 {
 653         struct hv_driver *drv = drv_to_hv_drv(driver);
 654         uuid_le guid = NULL_UUID_LE;
 655         ssize_t retval;
 656
 657         if (get_uuid_le(buf, &guid) != 0)
 658                 return -EINVAL;
 659
 660         if (hv_vmbus_get_id(drv, &guid))
 661                 return -EEXIST;
 662
 663         retval = vmbus_add_dynid(drv, &guid);
 664         if (retval)
 665                 return retval;
 666         return count;
 667 }
 668 static DRIVER_ATTR_WO(new_id);
 669
 670 /*
 671  * store_remove_id - remove a PCI device ID from this driver
 672  *
 673  * Removes a dynamic pci device ID to this driver.
 674  */
 675 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 676                                size_t count)
 677 {
 678         struct hv_driver *drv = drv_to_hv_drv(driver);
 679         struct vmbus_dynid *dynid, *n;
 680         uuid_le guid = NULL_UUID_LE;
 681         size_t retval = -ENODEV;
 682
 683         if (get_uuid_le(buf, &guid))
 684                 return -EINVAL;
 685
 686         spin_lock(&drv->dynids.lock);
 687         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 688                 struct hv_vmbus_device_id *id = &dynid->id;
 689
 690                 if (!uuid_le_cmp(id->guid, guid)) {
 691                         list_del(&dynid->node);
 692                         kfree(dynid);
 693                         retval = count;
 694                         break;
 695                 }
 696         }
 697         spin_unlock(&drv->dynids.lock);
 698
 699         return retval;
 700 }
 701 static DRIVER_ATTR_WO(remove_id);
 702
 703 static struct attribute *vmbus_drv_attrs[] = {
 704         &driver_attr_new_id.attr,
 705         &driver_attr_remove_id.attr,
 706         NULL,
 707 };
 708 ATTRIBUTE_GROUPS(vmbus_drv);
 709
 710
 711 /*
 712  * vmbus_match - Attempt to match the specified device to the specified driver
 713  */
 714 static int vmbus_match(struct device *device, struct device_driver *driver)
 715 {
 716         struct hv_driver *drv = drv_to_hv_drv(driver);
 717         struct hv_device *hv_dev = device_to_hv_device(device);
 718
 719         /* The hv_sock driver handles all hv_sock offers. */
 720         if (is_hvsock_channel(hv_dev->channel))
 721                 return drv->hvsock;
 722
 723         if (hv_vmbus_get_id(drv, &hv_dev->dev_type))
 724                 return 1;
 725
 726         return 0;
 727 }
 728
 729 /*
 730  * vmbus_probe - Add the new vmbus's child device
 731  */
 732 static int vmbus_probe(struct device *child_device)
 733 {
 734         int ret = 0;
 735         struct hv_driver *drv =
 736                         drv_to_hv_drv(child_device->driver);
 737         struct hv_device *dev = device_to_hv_device(child_device);
 738         const struct hv_vmbus_device_id *dev_id;
 739
 740         dev_id = hv_vmbus_get_id(drv, &dev->dev_type);
 741         if (drv->probe) {
 742                 ret = drv->probe(dev, dev_id);
 743                 if (ret != 0)
 744                         pr_err("probe failed for device %s (%d)\n",
 745                                dev_name(child_device), ret);
 746
 747         } else {
 748                 pr_err("probe not set for driver %s\n",
 749                        dev_name(child_device));
 750                 ret = -ENODEV;
 751         }
 752         return ret;
 753 }
 754
 755 /*
 756  * vmbus_remove - Remove a vmbus device
 757  */
 758 static int vmbus_remove(struct device *child_device)
 759 {
 760         struct hv_driver *drv;
 761         struct hv_device *dev = device_to_hv_device(child_device);
 762
 763         if (child_device->driver) {
 764                 drv = drv_to_hv_drv(child_device->driver);
 765                 if (drv->remove)
 766                         drv->remove(dev);
 767         }
 768
 769         return 0;
 770 }
 771
 772
 773 /*
 774  * vmbus_shutdown - Shutdown a vmbus device
 775  */
 776 static void vmbus_shutdown(struct device *child_device)
 777 {
 778         struct hv_driver *drv;
 779         struct hv_device *dev = device_to_hv_device(child_device);
 780
 781
 782         /* The device may not be attached yet */
 783         if (!child_device->driver)
 784                 return;
 785
 786         drv = drv_to_hv_drv(child_device->driver);
 787
 788         if (drv->shutdown)
 789                 drv->shutdown(dev);
 790 }
 791
 792
 793 /*
 794  * vmbus_device_release - Final callback release of the vmbus child device
 795  */
 796 static void vmbus_device_release(struct device *device)
 797 {
 798         struct hv_device *hv_dev = device_to_hv_device(device);
 799         struct vmbus_channel *channel = hv_dev->channel;
 800
 801         hv_process_channel_removal(channel,
 802                                    channel->offermsg.child_relid);
 803         kfree(hv_dev);
 804
 805 }
 806
 807 /* The one and only one */
 808 static struct bus_type  hv_bus = {
 809         .name =         "vmbus",
 810         .match =                vmbus_match,
 811         .shutdown =             vmbus_shutdown,
 812         .remove =               vmbus_remove,
 813         .probe =                vmbus_probe,
 814         .uevent =               vmbus_uevent,
 815         .dev_groups =           vmbus_dev_groups,
 816         .drv_groups =           vmbus_drv_groups,
 817 };
 818
 819 struct onmessage_work_context {
 820         struct work_struct work;
 821         struct hv_message msg;
 822 };
 823
 824 static void vmbus_onmessage_work(struct work_struct *work)
 825 {
 826         struct onmessage_work_context *ctx;
 827
 828         /* Do not process messages if we're in DISCONNECTED state */
 829         if (vmbus_connection.conn_state == DISCONNECTED)
 830                 return;
 831
 832         ctx = container_of(work, struct onmessage_work_context,
 833                            work);
 834         vmbus_onmessage(&ctx->msg);
 835         kfree(ctx);
 836 }
 837
 838 static void hv_process_timer_expiration(struct hv_message *msg,
 839                                         struct hv_per_cpu_context *hv_cpu)
 840 {
 841         struct clock_event_device *dev = hv_cpu->clk_evt;
 842
 843         if (dev->event_handler)
 844                 dev->event_handler(dev);
 845
 846         vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
 847 }
 848
 849 void vmbus_on_msg_dpc(unsigned long data)
 850 {
 851         struct hv_per_cpu_context *hv_cpu = (void *)data;
 852         void *page_addr = hv_cpu->synic_message_page;
 853         struct hv_message *msg = (struct hv_message *)page_addr +
 854                                   VMBUS_MESSAGE_SINT;
 855         struct vmbus_channel_message_header *hdr;
 856         const struct vmbus_channel_message_table_entry *entry;
 857         struct onmessage_work_context *ctx;
 858         u32 message_type = msg->header.message_type;
 859
 860         if (message_type == HVMSG_NONE)
 861                 /* no msg */
 862                 return;
 863
 864         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 865
 866         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 867                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
 868                 goto msg_handled;
 869         }
 870
 871         entry = &channel_message_table[hdr->msgtype];
 872         if (entry->handler_type == VMHT_BLOCKING) {
 873                 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 874                 if (ctx == NULL)
 875                         return;
 876
 877                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
 878                 memcpy(&ctx->msg, msg, sizeof(*msg));
 879
 880                 queue_work(vmbus_connection.work_queue, &ctx->work);
 881         } else
 882                 entry->message_handler(hdr);
 883
 884 msg_handled:
 885         vmbus_signal_eom(msg, message_type);
 886 }
 887
 888
 889 /*
 890  * Direct callback for channels using other deferred processing
 891  */
 892 static void vmbus_channel_isr(struct vmbus_channel *channel)
 893 {
 894         void (*callback_fn)(void *);
 895
 896         callback_fn = READ_ONCE(channel->onchannel_callback);
 897         if (likely(callback_fn != NULL))
 898                 (*callback_fn)(channel->channel_callback_context);
 899 }
 900
 901 /*
 902  * Schedule all channels with events pending
 903  */
 904 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
 905 {
 906         unsigned long *recv_int_page;
 907         u32 maxbits, relid;
 908
 909         if (vmbus_proto_version < VERSION_WIN8) {
 910                 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
 911                 recv_int_page = vmbus_connection.recv_int_page;
 912         } else {
 913                 /*
 914                  * When the host is win8 and beyond, the event page
 915                  * can be directly checked to get the id of the channel
 916                  * that has the interrupt pending.
 917                  */
 918                 void *page_addr = hv_cpu->synic_event_page;
 919                 union hv_synic_event_flags *event
 920                         = (union hv_synic_event_flags *)page_addr +
 921                                                  VMBUS_MESSAGE_SINT;
 922
 923                 maxbits = HV_EVENT_FLAGS_COUNT;
 924                 recv_int_page = event->flags;
 925         }
 926
 927         if (unlikely(!recv_int_page))
 928                 return;
 929
 930         for_each_set_bit(relid, recv_int_page, maxbits) {
 931                 struct vmbus_channel *channel;
 932
 933                 if (!sync_test_and_clear_bit(relid, recv_int_page))
 934                         continue;
 935
 936                 /* Special case - vmbus channel protocol msg */
 937                 if (relid == 0)
 938                         continue;
 939
 940                 rcu_read_lock();
 941
 942                 /* Find channel based on relid */
 943                 list_for_each_entry_rcu(channel, &hv_cpu->chan_list, percpu_list) {
 944                         if (channel->offermsg.child_relid != relid)
 945                                 continue;
 946
 947                         switch (channel->callback_mode) {
 948                         case HV_CALL_ISR:
 949                                 vmbus_channel_isr(channel);
 950                                 break;
 951
 952                         case HV_CALL_BATCHED:
 953                                 hv_begin_read(&channel->inbound);
 954                                 /* fallthrough */
 955                         case HV_CALL_DIRECT:
 956                                 tasklet_schedule(&channel->callback_event);
 957                         }
 958                 }
 959
 960                 rcu_read_unlock();
 961         }
 962 }
 963
 964 static void vmbus_isr(void)
 965 {
 966         struct hv_per_cpu_context *hv_cpu
 967                 = this_cpu_ptr(hv_context.cpu_context);
 968         void *page_addr = hv_cpu->synic_event_page;
 969         struct hv_message *msg;
 970         union hv_synic_event_flags *event;
 971         bool handled = false;
 972
 973         if (unlikely(page_addr == NULL))
 974                 return;
 975
 976         event = (union hv_synic_event_flags *)page_addr +
 977                                          VMBUS_MESSAGE_SINT;
 978         /*
 979          * Check for events before checking for messages. This is the order
 980          * in which events and messages are checked in Windows guests on
 981          * Hyper-V, and the Windows team suggested we do the same.
 982          */
 983
 984         if ((vmbus_proto_version == VERSION_WS2008) ||
 985                 (vmbus_proto_version == VERSION_WIN7)) {
 986
 987                 /* Since we are a child, we only need to check bit 0 */
 988                 if (sync_test_and_clear_bit(0, event->flags))
 989                         handled = true;
 990         } else {
 991                 /*
 992                  * Our host is win8 or above. The signaling mechanism
 993                  * has changed and we can directly look at the event page.
 994                  * If bit n is set then we have an interrup on the channel
 995                  * whose id is n.
 996                  */
 997                 handled = true;
 998         }
 999
1000         if (handled)
1001                 vmbus_chan_sched(hv_cpu);
1002
1003         page_addr = hv_cpu->synic_message_page;
1004         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1005
1006         /* Check if there are actual msgs to be processed */
1007         if (msg->header.message_type != HVMSG_NONE) {
1008                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
1009                         hv_process_timer_expiration(msg, hv_cpu);
1010                 else
1011                         tasklet_schedule(&hv_cpu->msg_dpc);
1012         }
1013
1014         add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1015 }
1016
1017
1018 /*
1019  * vmbus_bus_init -Main vmbus driver initialization routine.
1020  *
1021  * Here, we
1022  *      - initialize the vmbus driver context
1023  *      - invoke the vmbus hv main init routine
1024  *      - retrieve the channel offers
1025  */
1026 static int vmbus_bus_init(void)
1027 {
1028         int ret;
1029
1030         /* Hypervisor initialization...setup hypercall page..etc */
1031         ret = hv_init();
1032         if (ret != 0) {
1033                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1034                 return ret;
1035         }
1036
1037         ret = bus_register(&hv_bus);
1038         if (ret)
1039                 return ret;
1040
1041         hv_setup_vmbus_irq(vmbus_isr);
1042
1043         ret = hv_synic_alloc();
1044         if (ret)
1045                 goto err_alloc;
1046         /*
1047          * Initialize the per-cpu interrupt state and
1048          * connect to the host.
1049          */
1050         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv:online",
1051                                 hv_synic_init, hv_synic_cleanup);
1052         if (ret < 0)
1053                 goto err_alloc;
1054         hyperv_cpuhp_online = ret;
1055
1056         ret = vmbus_connect();
1057         if (ret)
1058                 goto err_connect;
1059
1060         /*
1061          * Only register if the crash MSRs are available
1062          */
1063         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1064                 register_die_notifier(&hyperv_die_block);
1065                 atomic_notifier_chain_register(&panic_notifier_list,
1066                                                &hyperv_panic_block);
1067         }
1068
1069         vmbus_request_offers();
1070
1071         return 0;
1072
1073 err_connect:
1074         cpuhp_remove_state(hyperv_cpuhp_online);
1075 err_alloc:
1076         hv_synic_free();
1077         hv_remove_vmbus_irq();
1078
1079         bus_unregister(&hv_bus);
1080
1081         return ret;
1082 }
1083
1084 /**
1085  * __vmbus_child_driver_register() - Register a vmbus's driver
1086  * @hv_driver: Pointer to driver structure you want to register
1087  * @owner: owner module of the drv
1088  * @mod_name: module name string
1089  *
1090  * Registers the given driver with Linux through the 'driver_register()' call
1091  * and sets up the hyper-v vmbus handling for this driver.
1092  * It will return the state of the 'driver_register()' call.
1093  *
1094  */
1095 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1096 {
1097         int ret;
1098
1099         pr_info("registering driver %s\n", hv_driver->name);
1100
1101         ret = vmbus_exists();
1102         if (ret < 0)
1103                 return ret;
1104
1105         hv_driver->driver.name = hv_driver->name;
1106         hv_driver->driver.owner = owner;
1107         hv_driver->driver.mod_name = mod_name;
1108         hv_driver->driver.bus = &hv_bus;
1109
1110         spin_lock_init(&hv_driver->dynids.lock);
1111         INIT_LIST_HEAD(&hv_driver->dynids.list);
1112
1113         ret = driver_register(&hv_driver->driver);
1114
1115         return ret;
1116 }
1117 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1118
1119 /**
1120  * vmbus_driver_unregister() - Unregister a vmbus's driver
1121  * @hv_driver: Pointer to driver structure you want to
1122  *             un-register
1123  *
1124  * Un-register the given driver that was previous registered with a call to
1125  * vmbus_driver_register()
1126  */
1127 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1128 {
1129         pr_info("unregistering driver %s\n", hv_driver->name);
1130
1131         if (!vmbus_exists()) {
1132                 driver_unregister(&hv_driver->driver);
1133                 vmbus_free_dynids(hv_driver);
1134         }
1135 }
1136 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1137
1138 /*
1139  * vmbus_device_create - Creates and registers a new child device
1140  * on the vmbus.
1141  */
1142 struct hv_device *vmbus_device_create(const uuid_le *type,
1143                                       const uuid_le *instance,
1144                                       struct vmbus_channel *channel)
1145 {
1146         struct hv_device *child_device_obj;
1147
1148         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1149         if (!child_device_obj) {
1150                 pr_err("Unable to allocate device object for child device\n");
1151                 return NULL;
1152         }
1153
1154         child_device_obj->channel = channel;
1155         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
1156         memcpy(&child_device_obj->dev_instance, instance,
1157                sizeof(uuid_le));
1158         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1159
1160
1161         return child_device_obj;
1162 }
1163
1164 /*
1165  * vmbus_device_register - Register the child device
1166  */
1167 int vmbus_device_register(struct hv_device *child_device_obj)
1168 {
1169         int ret = 0;
1170
1171         dev_set_name(&child_device_obj->device, "%pUl",
1172                      child_device_obj->channel->offermsg.offer.if_instance.b);
1173
1174         child_device_obj->device.bus = &hv_bus;
1175         child_device_obj->device.parent = &hv_acpi_dev->dev;
1176         child_device_obj->device.release = vmbus_device_release;
1177
1178         /*
1179          * Register with the LDM. This will kick off the driver/device
1180          * binding...which will eventually call vmbus_match() and vmbus_probe()
1181          */
1182         ret = device_register(&child_device_obj->device);
1183
1184         if (ret)
1185                 pr_err("Unable to register child device\n");
1186         else
1187                 pr_debug("child device %s registered\n",
1188                         dev_name(&child_device_obj->device));
1189
1190         return ret;
1191 }
1192
1193 /*
1194  * vmbus_device_unregister - Remove the specified child device
1195  * from the vmbus.
1196  */
1197 void vmbus_device_unregister(struct hv_device *device_obj)
1198 {
1199         pr_debug("child device %s unregistered\n",
1200                 dev_name(&device_obj->device));
1201
1202         /*
1203          * Kick off the process of unregistering the device.
1204          * This will call vmbus_remove() and eventually vmbus_device_release()
1205          */
1206         device_unregister(&device_obj->device);
1207 }
1208
1209
1210 /*
1211  * VMBUS is an acpi enumerated device. Get the information we
1212  * need from DSDT.
1213  */
1214 #define VTPM_BASE_ADDRESS 0xfed40000
1215 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1216 {
1217         resource_size_t start = 0;
1218         resource_size_t end = 0;
1219         struct resource *new_res;
1220         struct resource **old_res = &hyperv_mmio;
1221         struct resource **prev_res = NULL;
1222
1223         switch (res->type) {
1224
1225         /*
1226          * "Address" descriptors are for bus windows. Ignore
1227          * "memory" descriptors, which are for registers on
1228          * devices.
1229          */
1230         case ACPI_RESOURCE_TYPE_ADDRESS32:
1231                 start = res->data.address32.address.minimum;
1232                 end = res->data.address32.address.maximum;
1233                 break;
1234
1235         case ACPI_RESOURCE_TYPE_ADDRESS64:
1236                 start = res->data.address64.address.minimum;
1237                 end = res->data.address64.address.maximum;
1238                 break;
1239
1240         default:
1241                 /* Unused resource type */
1242                 return AE_OK;
1243
1244         }
1245         /*
1246          * Ignore ranges that are below 1MB, as they're not
1247          * necessary or useful here.
1248          */
1249         if (end < 0x100000)
1250                 return AE_OK;
1251
1252         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1253         if (!new_res)
1254                 return AE_NO_MEMORY;
1255
1256         /* If this range overlaps the virtual TPM, truncate it. */
1257         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1258                 end = VTPM_BASE_ADDRESS;
1259
1260         new_res->name = "hyperv mmio";
1261         new_res->flags = IORESOURCE_MEM;
1262         new_res->start = start;
1263         new_res->end = end;
1264
1265         /*
1266          * If two ranges are adjacent, merge them.
1267          */
1268         do {
1269                 if (!*old_res) {
1270                         *old_res = new_res;
1271                         break;
1272                 }
1273
1274                 if (((*old_res)->end + 1) == new_res->start) {
1275                         (*old_res)->end = new_res->end;
1276                         kfree(new_res);
1277                         break;
1278                 }
1279
1280                 if ((*old_res)->start == new_res->end + 1) {
1281                         (*old_res)->start = new_res->start;
1282                         kfree(new_res);
1283                         break;
1284                 }
1285
1286                 if ((*old_res)->start > new_res->end) {
1287                         new_res->sibling = *old_res;
1288                         if (prev_res)
1289                                 (*prev_res)->sibling = new_res;
1290                         *old_res = new_res;
1291                         break;
1292                 }
1293
1294                 prev_res = old_res;
1295                 old_res = &(*old_res)->sibling;
1296
1297         } while (1);
1298
1299         return AE_OK;
1300 }
1301
1302 static int vmbus_acpi_remove(struct acpi_device *device)
1303 {
1304         struct resource *cur_res;
1305         struct resource *next_res;
1306
1307         if (hyperv_mmio) {
1308                 if (fb_mmio) {
1309                         __release_region(hyperv_mmio, fb_mmio->start,
1310                                          resource_size(fb_mmio));
1311                         fb_mmio = NULL;
1312                 }
1313
1314                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1315                         next_res = cur_res->sibling;
1316                         kfree(cur_res);
1317                 }
1318         }
1319
1320         return 0;
1321 }
1322
1323 static void vmbus_reserve_fb(void)
1324 {
1325         int size;
1326         /*
1327          * Make a claim for the frame buffer in the resource tree under the
1328          * first node, which will be the one below 4GB.  The length seems to
1329          * be underreported, particularly in a Generation 1 VM.  So start out
1330          * reserving a larger area and make it smaller until it succeeds.
1331          */
1332
1333         if (screen_info.lfb_base) {
1334                 if (efi_enabled(EFI_BOOT))
1335                         size = max_t(__u32, screen_info.lfb_size, 0x800000);
1336                 else
1337                         size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1338
1339                 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1340                         fb_mmio = __request_region(hyperv_mmio,
1341                                                    screen_info.lfb_base, size,
1342                                                    fb_mmio_name, 0);
1343                 }
1344         }
1345 }
1346
1347 /**
1348  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1349  * @new:                If successful, supplied a pointer to the
1350  *                      allocated MMIO space.
1351  * @device_obj:         Identifies the caller
1352  * @min:                Minimum guest physical address of the
1353  *                      allocation
1354  * @max:                Maximum guest physical address
1355  * @size:               Size of the range to be allocated
1356  * @align:              Alignment of the range to be allocated
1357  * @fb_overlap_ok:      Whether this allocation can be allowed
1358  *                      to overlap the video frame buffer.
1359  *
1360  * This function walks the resources granted to VMBus by the
1361  * _CRS object in the ACPI namespace underneath the parent
1362  * "bridge" whether that's a root PCI bus in the Generation 1
1363  * case or a Module Device in the Generation 2 case.  It then
1364  * attempts to allocate from the global MMIO pool in a way that
1365  * matches the constraints supplied in these parameters and by
1366  * that _CRS.
1367  *
1368  * Return: 0 on success, -errno on failure
1369  */
1370 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1371                         resource_size_t min, resource_size_t max,
1372                         resource_size_t size, resource_size_t align,
1373                         bool fb_overlap_ok)
1374 {
1375         struct resource *iter, *shadow;
1376         resource_size_t range_min, range_max, start;
1377         const char *dev_n = dev_name(&device_obj->device);
1378         int retval;
1379
1380         retval = -ENXIO;
1381         down(&hyperv_mmio_lock);
1382
1383         /*
1384          * If overlaps with frame buffers are allowed, then first attempt to
1385          * make the allocation from within the reserved region.  Because it
1386          * is already reserved, no shadow allocation is necessary.
1387          */
1388         if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1389             !(max < fb_mmio->start)) {
1390
1391                 range_min = fb_mmio->start;
1392                 range_max = fb_mmio->end;
1393                 start = (range_min + align - 1) & ~(align - 1);
1394                 for (; start + size - 1 <= range_max; start += align) {
1395                         *new = request_mem_region_exclusive(start, size, dev_n);
1396                         if (*new) {
1397                                 retval = 0;
1398                                 goto exit;
1399                         }
1400                 }
1401         }
1402
1403         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1404                 if ((iter->start >= max) || (iter->end <= min))
1405                         continue;
1406
1407                 range_min = iter->start;
1408                 range_max = iter->end;
1409                 start = (range_min + align - 1) & ~(align - 1);
1410                 for (; start + size - 1 <= range_max; start += align) {
1411                         shadow = __request_region(iter, start, size, NULL,
1412                                                   IORESOURCE_BUSY);
1413                         if (!shadow)
1414                                 continue;
1415
1416                         *new = request_mem_region_exclusive(start, size, dev_n);
1417                         if (*new) {
1418                                 shadow->name = (char *)*new;
1419                                 retval = 0;
1420                                 goto exit;
1421                         }
1422
1423                         __release_region(iter, start, size);
1424                 }
1425         }
1426
1427 exit:
1428         up(&hyperv_mmio_lock);
1429         return retval;
1430 }
1431 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1432
1433 /**
1434  * vmbus_free_mmio() - Free a memory-mapped I/O range.
1435  * @start:              Base address of region to release.
1436  * @size:               Size of the range to be allocated
1437  *
1438  * This function releases anything requested by
1439  * vmbus_mmio_allocate().
1440  */
1441 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
1442 {
1443         struct resource *iter;
1444
1445         down(&hyperv_mmio_lock);
1446         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1447                 if ((iter->start >= start + size) || (iter->end <= start))
1448                         continue;
1449
1450                 __release_region(iter, start, size);
1451         }
1452         release_mem_region(start, size);
1453         up(&hyperv_mmio_lock);
1454
1455 }
1456 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
1457
1458 /**
1459  * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
1460  * @cpu_number: CPU number in Linux terms
1461  *
1462  * This function returns the mapping between the Linux processor
1463  * number and the hypervisor's virtual processor number, useful
1464  * in making hypercalls and such that talk about specific
1465  * processors.
1466  *
1467  * Return: Virtual processor number in Hyper-V terms
1468  */
1469 int vmbus_cpu_number_to_vp_number(int cpu_number)
1470 {
1471         return hv_context.vp_index[cpu_number];
1472 }
1473 EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
1474
1475 static int vmbus_acpi_add(struct acpi_device *device)
1476 {
1477         acpi_status result;
1478         int ret_val = -ENODEV;
1479         struct acpi_device *ancestor;
1480
1481         hv_acpi_dev = device;
1482
1483         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1484                                         vmbus_walk_resources, NULL);
1485
1486         if (ACPI_FAILURE(result))
1487                 goto acpi_walk_err;
1488         /*
1489          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1490          * firmware) is the VMOD that has the mmio ranges. Get that.
1491          */
1492         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1493                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1494                                              vmbus_walk_resources, NULL);
1495
1496                 if (ACPI_FAILURE(result))
1497                         continue;
1498                 if (hyperv_mmio) {
1499                         vmbus_reserve_fb();
1500                         break;
1501                 }
1502         }
1503         ret_val = 0;
1504
1505 acpi_walk_err:
1506         complete(&probe_event);
1507         if (ret_val)
1508                 vmbus_acpi_remove(device);
1509         return ret_val;
1510 }
1511
1512 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1513         {"VMBUS", 0},
1514         {"VMBus", 0},
1515         {"", 0},
1516 };
1517 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1518
1519 static struct acpi_driver vmbus_acpi_driver = {
1520         .name = "vmbus",
1521         .ids = vmbus_acpi_device_ids,
1522         .ops = {
1523                 .add = vmbus_acpi_add,
1524                 .remove = vmbus_acpi_remove,
1525         },
1526 };
1527
1528 static void hv_kexec_handler(void)
1529 {
1530         hv_synic_clockevents_cleanup();
1531         vmbus_initiate_unload(false);
1532         vmbus_connection.conn_state = DISCONNECTED;
1533         /* Make sure conn_state is set as hv_synic_cleanup checks for it */
1534         mb();
1535         cpuhp_remove_state(hyperv_cpuhp_online);
1536         hyperv_cleanup();
1537 };
1538
1539 static void hv_crash_handler(struct pt_regs *regs)
1540 {
1541         vmbus_initiate_unload(true);
1542         /*
1543          * In crash handler we can't schedule synic cleanup for all CPUs,
1544          * doing the cleanup for current CPU only. This should be sufficient
1545          * for kdump.
1546          */
1547         vmbus_connection.conn_state = DISCONNECTED;
1548         hv_synic_cleanup(smp_processor_id());
1549         hyperv_cleanup();
1550 };
1551
1552 static int __init hv_acpi_init(void)
1553 {
1554         int ret, t;
1555
1556         if (x86_hyper != &x86_hyper_ms_hyperv)
1557                 return -ENODEV;
1558
1559         init_completion(&probe_event);
1560
1561         /*
1562          * Get ACPI resources first.
1563          */
1564         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1565
1566         if (ret)
1567                 return ret;
1568
1569         t = wait_for_completion_timeout(&probe_event, 5*HZ);
1570         if (t == 0) {
1571                 ret = -ETIMEDOUT;
1572                 goto cleanup;
1573         }
1574
1575         ret = vmbus_bus_init();
1576         if (ret)
1577                 goto cleanup;
1578
1579         hv_setup_kexec_handler(hv_kexec_handler);
1580         hv_setup_crash_handler(hv_crash_handler);
1581
1582         return 0;
1583
1584 cleanup:
1585         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1586         hv_acpi_dev = NULL;
1587         return ret;
1588 }
1589
1590 static void __exit vmbus_exit(void)
1591 {
1592         int cpu;
1593
1594         hv_remove_kexec_handler();
1595         hv_remove_crash_handler();
1596         vmbus_connection.conn_state = DISCONNECTED;
1597         hv_synic_clockevents_cleanup();
1598         vmbus_disconnect();
1599         hv_remove_vmbus_irq();
1600         for_each_online_cpu(cpu) {
1601                 struct hv_per_cpu_context *hv_cpu
1602                         = per_cpu_ptr(hv_context.cpu_context, cpu);
1603
1604                 tasklet_kill(&hv_cpu->msg_dpc);
1605         }
1606         vmbus_free_channels();
1607
1608         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1609                 unregister_die_notifier(&hyperv_die_block);
1610                 atomic_notifier_chain_unregister(&panic_notifier_list,
1611                                                  &hyperv_panic_block);
1612         }
1613         bus_unregister(&hv_bus);
1614
1615         cpuhp_remove_state(hyperv_cpuhp_online);
1616         hv_synic_free();
1617         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1618 }
1619
1620
1621 MODULE_LICENSE("GPL");
1622
1623 subsys_initcall(hv_acpi_init);
1624 module_exit(vmbus_exit);