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 <asm/hyperv.h>
  36 #include <asm/hypervisor.h>
  37 #include <asm/mshyperv.h>
  38 #include "hyperv_vmbus.h"
  39
  40 static struct acpi_device  *hv_acpi_dev;
  41
  42 static struct tasklet_struct msg_dpc;
  43 static struct completion probe_event;
  44 static int irq;
  45
  46 struct resource hyperv_mmio = {
  47         .name  = "hyperv mmio",
  48         .flags = IORESOURCE_MEM,
  49 };
  50 EXPORT_SYMBOL_GPL(hyperv_mmio);
  51
  52 static int vmbus_exists(void)
  53 {
  54         if (hv_acpi_dev == NULL)
  55                 return -ENODEV;
  56
  57         return 0;
  58 }
  59
  60 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
  61 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
  62 {
  63         int i;
  64         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
  65                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
  66 }
  67
  68 static u8 channel_monitor_group(struct vmbus_channel *channel)
  69 {
  70         return (u8)channel->offermsg.monitorid / 32;
  71 }
  72
  73 static u8 channel_monitor_offset(struct vmbus_channel *channel)
  74 {
  75         return (u8)channel->offermsg.monitorid % 32;
  76 }
  77
  78 static u32 channel_pending(struct vmbus_channel *channel,
  79                            struct hv_monitor_page *monitor_page)
  80 {
  81         u8 monitor_group = channel_monitor_group(channel);
  82         return monitor_page->trigger_group[monitor_group].pending;
  83 }
  84
  85 static u32 channel_latency(struct vmbus_channel *channel,
  86                            struct hv_monitor_page *monitor_page)
  87 {
  88         u8 monitor_group = channel_monitor_group(channel);
  89         u8 monitor_offset = channel_monitor_offset(channel);
  90         return monitor_page->latency[monitor_group][monitor_offset];
  91 }
  92
  93 static u32 channel_conn_id(struct vmbus_channel *channel,
  94                            struct hv_monitor_page *monitor_page)
  95 {
  96         u8 monitor_group = channel_monitor_group(channel);
  97         u8 monitor_offset = channel_monitor_offset(channel);
  98         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
  99 }
 100
 101 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 102                        char *buf)
 103 {
 104         struct hv_device *hv_dev = device_to_hv_device(dev);
 105
 106         if (!hv_dev->channel)
 107                 return -ENODEV;
 108         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 109 }
 110 static DEVICE_ATTR_RO(id);
 111
 112 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 113                           char *buf)
 114 {
 115         struct hv_device *hv_dev = device_to_hv_device(dev);
 116
 117         if (!hv_dev->channel)
 118                 return -ENODEV;
 119         return sprintf(buf, "%d\n", hv_dev->channel->state);
 120 }
 121 static DEVICE_ATTR_RO(state);
 122
 123 static ssize_t monitor_id_show(struct device *dev,
 124                                struct device_attribute *dev_attr, char *buf)
 125 {
 126         struct hv_device *hv_dev = device_to_hv_device(dev);
 127
 128         if (!hv_dev->channel)
 129                 return -ENODEV;
 130         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
 131 }
 132 static DEVICE_ATTR_RO(monitor_id);
 133
 134 static ssize_t class_id_show(struct device *dev,
 135                                struct device_attribute *dev_attr, char *buf)
 136 {
 137         struct hv_device *hv_dev = device_to_hv_device(dev);
 138
 139         if (!hv_dev->channel)
 140                 return -ENODEV;
 141         return sprintf(buf, "{%pUl}\n",
 142                        hv_dev->channel->offermsg.offer.if_type.b);
 143 }
 144 static DEVICE_ATTR_RO(class_id);
 145
 146 static ssize_t device_id_show(struct device *dev,
 147                               struct device_attribute *dev_attr, char *buf)
 148 {
 149         struct hv_device *hv_dev = device_to_hv_device(dev);
 150
 151         if (!hv_dev->channel)
 152                 return -ENODEV;
 153         return sprintf(buf, "{%pUl}\n",
 154                        hv_dev->channel->offermsg.offer.if_instance.b);
 155 }
 156 static DEVICE_ATTR_RO(device_id);
 157
 158 static ssize_t modalias_show(struct device *dev,
 159                              struct device_attribute *dev_attr, char *buf)
 160 {
 161         struct hv_device *hv_dev = device_to_hv_device(dev);
 162         char alias_name[VMBUS_ALIAS_LEN + 1];
 163
 164         print_alias_name(hv_dev, alias_name);
 165         return sprintf(buf, "vmbus:%s\n", alias_name);
 166 }
 167 static DEVICE_ATTR_RO(modalias);
 168
 169 static ssize_t server_monitor_pending_show(struct device *dev,
 170                                            struct device_attribute *dev_attr,
 171                                            char *buf)
 172 {
 173         struct hv_device *hv_dev = device_to_hv_device(dev);
 174
 175         if (!hv_dev->channel)
 176                 return -ENODEV;
 177         return sprintf(buf, "%d\n",
 178                        channel_pending(hv_dev->channel,
 179                                        vmbus_connection.monitor_pages[1]));
 180 }
 181 static DEVICE_ATTR_RO(server_monitor_pending);
 182
 183 static ssize_t client_monitor_pending_show(struct device *dev,
 184                                            struct device_attribute *dev_attr,
 185                                            char *buf)
 186 {
 187         struct hv_device *hv_dev = device_to_hv_device(dev);
 188
 189         if (!hv_dev->channel)
 190                 return -ENODEV;
 191         return sprintf(buf, "%d\n",
 192                        channel_pending(hv_dev->channel,
 193                                        vmbus_connection.monitor_pages[1]));
 194 }
 195 static DEVICE_ATTR_RO(client_monitor_pending);
 196
 197 static ssize_t server_monitor_latency_show(struct device *dev,
 198                                            struct device_attribute *dev_attr,
 199                                            char *buf)
 200 {
 201         struct hv_device *hv_dev = device_to_hv_device(dev);
 202
 203         if (!hv_dev->channel)
 204                 return -ENODEV;
 205         return sprintf(buf, "%d\n",
 206                        channel_latency(hv_dev->channel,
 207                                        vmbus_connection.monitor_pages[0]));
 208 }
 209 static DEVICE_ATTR_RO(server_monitor_latency);
 210
 211 static ssize_t client_monitor_latency_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_latency(hv_dev->channel,
 221                                        vmbus_connection.monitor_pages[1]));
 222 }
 223 static DEVICE_ATTR_RO(client_monitor_latency);
 224
 225 static ssize_t server_monitor_conn_id_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_conn_id(hv_dev->channel,
 235                                        vmbus_connection.monitor_pages[0]));
 236 }
 237 static DEVICE_ATTR_RO(server_monitor_conn_id);
 238
 239 static ssize_t client_monitor_conn_id_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_conn_id(hv_dev->channel,
 249                                        vmbus_connection.monitor_pages[1]));
 250 }
 251 static DEVICE_ATTR_RO(client_monitor_conn_id);
 252
 253 static ssize_t out_intr_mask_show(struct device *dev,
 254                                   struct device_attribute *dev_attr, char *buf)
 255 {
 256         struct hv_device *hv_dev = device_to_hv_device(dev);
 257         struct hv_ring_buffer_debug_info outbound;
 258
 259         if (!hv_dev->channel)
 260                 return -ENODEV;
 261         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 262         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 263 }
 264 static DEVICE_ATTR_RO(out_intr_mask);
 265
 266 static ssize_t out_read_index_show(struct device *dev,
 267                                    struct device_attribute *dev_attr, char *buf)
 268 {
 269         struct hv_device *hv_dev = device_to_hv_device(dev);
 270         struct hv_ring_buffer_debug_info outbound;
 271
 272         if (!hv_dev->channel)
 273                 return -ENODEV;
 274         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 275         return sprintf(buf, "%d\n", outbound.current_read_index);
 276 }
 277 static DEVICE_ATTR_RO(out_read_index);
 278
 279 static ssize_t out_write_index_show(struct device *dev,
 280                                     struct device_attribute *dev_attr,
 281                                     char *buf)
 282 {
 283         struct hv_device *hv_dev = device_to_hv_device(dev);
 284         struct hv_ring_buffer_debug_info outbound;
 285
 286         if (!hv_dev->channel)
 287                 return -ENODEV;
 288         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 289         return sprintf(buf, "%d\n", outbound.current_write_index);
 290 }
 291 static DEVICE_ATTR_RO(out_write_index);
 292
 293 static ssize_t out_read_bytes_avail_show(struct device *dev,
 294                                          struct device_attribute *dev_attr,
 295                                          char *buf)
 296 {
 297         struct hv_device *hv_dev = device_to_hv_device(dev);
 298         struct hv_ring_buffer_debug_info outbound;
 299
 300         if (!hv_dev->channel)
 301                 return -ENODEV;
 302         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 303         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 304 }
 305 static DEVICE_ATTR_RO(out_read_bytes_avail);
 306
 307 static ssize_t out_write_bytes_avail_show(struct device *dev,
 308                                           struct device_attribute *dev_attr,
 309                                           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.bytes_avail_towrite);
 318 }
 319 static DEVICE_ATTR_RO(out_write_bytes_avail);
 320
 321 static ssize_t in_intr_mask_show(struct device *dev,
 322                                  struct device_attribute *dev_attr, char *buf)
 323 {
 324         struct hv_device *hv_dev = device_to_hv_device(dev);
 325         struct hv_ring_buffer_debug_info inbound;
 326
 327         if (!hv_dev->channel)
 328                 return -ENODEV;
 329         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 330         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 331 }
 332 static DEVICE_ATTR_RO(in_intr_mask);
 333
 334 static ssize_t in_read_index_show(struct device *dev,
 335                                   struct device_attribute *dev_attr, char *buf)
 336 {
 337         struct hv_device *hv_dev = device_to_hv_device(dev);
 338         struct hv_ring_buffer_debug_info inbound;
 339
 340         if (!hv_dev->channel)
 341                 return -ENODEV;
 342         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 343         return sprintf(buf, "%d\n", inbound.current_read_index);
 344 }
 345 static DEVICE_ATTR_RO(in_read_index);
 346
 347 static ssize_t in_write_index_show(struct device *dev,
 348                                    struct device_attribute *dev_attr, char *buf)
 349 {
 350         struct hv_device *hv_dev = device_to_hv_device(dev);
 351         struct hv_ring_buffer_debug_info inbound;
 352
 353         if (!hv_dev->channel)
 354                 return -ENODEV;
 355         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 356         return sprintf(buf, "%d\n", inbound.current_write_index);
 357 }
 358 static DEVICE_ATTR_RO(in_write_index);
 359
 360 static ssize_t in_read_bytes_avail_show(struct device *dev,
 361                                         struct device_attribute *dev_attr,
 362                                         char *buf)
 363 {
 364         struct hv_device *hv_dev = device_to_hv_device(dev);
 365         struct hv_ring_buffer_debug_info inbound;
 366
 367         if (!hv_dev->channel)
 368                 return -ENODEV;
 369         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 370         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 371 }
 372 static DEVICE_ATTR_RO(in_read_bytes_avail);
 373
 374 static ssize_t in_write_bytes_avail_show(struct device *dev,
 375                                          struct device_attribute *dev_attr,
 376                                          char *buf)
 377 {
 378         struct hv_device *hv_dev = device_to_hv_device(dev);
 379         struct hv_ring_buffer_debug_info inbound;
 380
 381         if (!hv_dev->channel)
 382                 return -ENODEV;
 383         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 384         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 385 }
 386 static DEVICE_ATTR_RO(in_write_bytes_avail);
 387
 388 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 389 static struct attribute *vmbus_attrs[] = {
 390         &dev_attr_id.attr,
 391         &dev_attr_state.attr,
 392         &dev_attr_monitor_id.attr,
 393         &dev_attr_class_id.attr,
 394         &dev_attr_device_id.attr,
 395         &dev_attr_modalias.attr,
 396         &dev_attr_server_monitor_pending.attr,
 397         &dev_attr_client_monitor_pending.attr,
 398         &dev_attr_server_monitor_latency.attr,
 399         &dev_attr_client_monitor_latency.attr,
 400         &dev_attr_server_monitor_conn_id.attr,
 401         &dev_attr_client_monitor_conn_id.attr,
 402         &dev_attr_out_intr_mask.attr,
 403         &dev_attr_out_read_index.attr,
 404         &dev_attr_out_write_index.attr,
 405         &dev_attr_out_read_bytes_avail.attr,
 406         &dev_attr_out_write_bytes_avail.attr,
 407         &dev_attr_in_intr_mask.attr,
 408         &dev_attr_in_read_index.attr,
 409         &dev_attr_in_write_index.attr,
 410         &dev_attr_in_read_bytes_avail.attr,
 411         &dev_attr_in_write_bytes_avail.attr,
 412         NULL,
 413 };
 414 ATTRIBUTE_GROUPS(vmbus);
 415
 416 /*
 417  * vmbus_uevent - add uevent for our device
 418  *
 419  * This routine is invoked when a device is added or removed on the vmbus to
 420  * generate a uevent to udev in the userspace. The udev will then look at its
 421  * rule and the uevent generated here to load the appropriate driver
 422  *
 423  * The alias string will be of the form vmbus:guid where guid is the string
 424  * representation of the device guid (each byte of the guid will be
 425  * represented with two hex characters.
 426  */
 427 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 428 {
 429         struct hv_device *dev = device_to_hv_device(device);
 430         int ret;
 431         char alias_name[VMBUS_ALIAS_LEN + 1];
 432
 433         print_alias_name(dev, alias_name);
 434         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 435         return ret;
 436 }
 437
 438 static uuid_le null_guid;
 439
 440 static inline bool is_null_guid(const __u8 *guid)
 441 {
 442         if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 443                 return false;
 444         return true;
 445 }
 446
 447 /*
 448  * Return a matching hv_vmbus_device_id pointer.
 449  * If there is no match, return NULL.
 450  */
 451 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 452                                         const struct hv_vmbus_device_id *id,
 453                                         __u8 *guid)
 454 {
 455         for (; !is_null_guid(id->guid); id++)
 456                 if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
 457                         return id;
 458
 459         return NULL;
 460 }
 461
 462
 463
 464 /*
 465  * vmbus_match - Attempt to match the specified device to the specified driver
 466  */
 467 static int vmbus_match(struct device *device, struct device_driver *driver)
 468 {
 469         struct hv_driver *drv = drv_to_hv_drv(driver);
 470         struct hv_device *hv_dev = device_to_hv_device(device);
 471
 472         if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
 473                 return 1;
 474
 475         return 0;
 476 }
 477
 478 /*
 479  * vmbus_probe - Add the new vmbus's child device
 480  */
 481 static int vmbus_probe(struct device *child_device)
 482 {
 483         int ret = 0;
 484         struct hv_driver *drv =
 485                         drv_to_hv_drv(child_device->driver);
 486         struct hv_device *dev = device_to_hv_device(child_device);
 487         const struct hv_vmbus_device_id *dev_id;
 488
 489         dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
 490         if (drv->probe) {
 491                 ret = drv->probe(dev, dev_id);
 492                 if (ret != 0)
 493                         pr_err("probe failed for device %s (%d)\n",
 494                                dev_name(child_device), ret);
 495
 496         } else {
 497                 pr_err("probe not set for driver %s\n",
 498                        dev_name(child_device));
 499                 ret = -ENODEV;
 500         }
 501         return ret;
 502 }
 503
 504 /*
 505  * vmbus_remove - Remove a vmbus device
 506  */
 507 static int vmbus_remove(struct device *child_device)
 508 {
 509         struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
 510         struct hv_device *dev = device_to_hv_device(child_device);
 511
 512         if (drv->remove)
 513                 drv->remove(dev);
 514         else
 515                 pr_err("remove not set for driver %s\n",
 516                         dev_name(child_device));
 517
 518         return 0;
 519 }
 520
 521
 522 /*
 523  * vmbus_shutdown - Shutdown a vmbus device
 524  */
 525 static void vmbus_shutdown(struct device *child_device)
 526 {
 527         struct hv_driver *drv;
 528         struct hv_device *dev = device_to_hv_device(child_device);
 529
 530
 531         /* The device may not be attached yet */
 532         if (!child_device->driver)
 533                 return;
 534
 535         drv = drv_to_hv_drv(child_device->driver);
 536
 537         if (drv->shutdown)
 538                 drv->shutdown(dev);
 539
 540         return;
 541 }
 542
 543
 544 /*
 545  * vmbus_device_release - Final callback release of the vmbus child device
 546  */
 547 static void vmbus_device_release(struct device *device)
 548 {
 549         struct hv_device *hv_dev = device_to_hv_device(device);
 550
 551         kfree(hv_dev);
 552
 553 }
 554
 555 /* The one and only one */
 556 static struct bus_type  hv_bus = {
 557         .name =         "vmbus",
 558         .match =                vmbus_match,
 559         .shutdown =             vmbus_shutdown,
 560         .remove =               vmbus_remove,
 561         .probe =                vmbus_probe,
 562         .uevent =               vmbus_uevent,
 563         .dev_groups =           vmbus_groups,
 564 };
 565
 566 struct onmessage_work_context {
 567         struct work_struct work;
 568         struct hv_message msg;
 569 };
 570
 571 static void vmbus_onmessage_work(struct work_struct *work)
 572 {
 573         struct onmessage_work_context *ctx;
 574
 575         ctx = container_of(work, struct onmessage_work_context,
 576                            work);
 577         vmbus_onmessage(&ctx->msg);
 578         kfree(ctx);
 579 }
 580
 581 static void vmbus_on_msg_dpc(unsigned long data)
 582 {
 583         int cpu = smp_processor_id();
 584         void *page_addr = hv_context.synic_message_page[cpu];
 585         struct hv_message *msg = (struct hv_message *)page_addr +
 586                                   VMBUS_MESSAGE_SINT;
 587         struct onmessage_work_context *ctx;
 588
 589         while (1) {
 590                 if (msg->header.message_type == HVMSG_NONE) {
 591                         /* no msg */
 592                         break;
 593                 } else {
 594                         ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 595                         if (ctx == NULL)
 596                                 continue;
 597                         INIT_WORK(&ctx->work, vmbus_onmessage_work);
 598                         memcpy(&ctx->msg, msg, sizeof(*msg));
 599                         queue_work(vmbus_connection.work_queue, &ctx->work);
 600                 }
 601
 602                 msg->header.message_type = HVMSG_NONE;
 603
 604                 /*
 605                  * Make sure the write to MessageType (ie set to
 606                  * HVMSG_NONE) happens before we read the
 607                  * MessagePending and EOMing. Otherwise, the EOMing
 608                  * will not deliver any more messages since there is
 609                  * no empty slot
 610                  */
 611                 mb();
 612
 613                 if (msg->header.message_flags.msg_pending) {
 614                         /*
 615                          * This will cause message queue rescan to
 616                          * possibly deliver another msg from the
 617                          * hypervisor
 618                          */
 619                         wrmsrl(HV_X64_MSR_EOM, 0);
 620                 }
 621         }
 622 }
 623
 624 static void vmbus_isr(void)
 625 {
 626         int cpu = smp_processor_id();
 627         void *page_addr;
 628         struct hv_message *msg;
 629         union hv_synic_event_flags *event;
 630         bool handled = false;
 631
 632         page_addr = hv_context.synic_event_page[cpu];
 633         if (page_addr == NULL)
 634                 return;
 635
 636         event = (union hv_synic_event_flags *)page_addr +
 637                                          VMBUS_MESSAGE_SINT;
 638         /*
 639          * Check for events before checking for messages. This is the order
 640          * in which events and messages are checked in Windows guests on
 641          * Hyper-V, and the Windows team suggested we do the same.
 642          */
 643
 644         if ((vmbus_proto_version == VERSION_WS2008) ||
 645                 (vmbus_proto_version == VERSION_WIN7)) {
 646
 647                 /* Since we are a child, we only need to check bit 0 */
 648                 if (sync_test_and_clear_bit(0,
 649                         (unsigned long *) &event->flags32[0])) {
 650                         handled = true;
 651                 }
 652         } else {
 653                 /*
 654                  * Our host is win8 or above. The signaling mechanism
 655                  * has changed and we can directly look at the event page.
 656                  * If bit n is set then we have an interrup on the channel
 657                  * whose id is n.
 658                  */
 659                 handled = true;
 660         }
 661
 662         if (handled)
 663                 tasklet_schedule(hv_context.event_dpc[cpu]);
 664
 665
 666         page_addr = hv_context.synic_message_page[cpu];
 667         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 668
 669         /* Check if there are actual msgs to be processed */
 670         if (msg->header.message_type != HVMSG_NONE)
 671                 tasklet_schedule(&msg_dpc);
 672 }
 673
 674 /*
 675  * vmbus_bus_init -Main vmbus driver initialization routine.
 676  *
 677  * Here, we
 678  *      - initialize the vmbus driver context
 679  *      - invoke the vmbus hv main init routine
 680  *      - get the irq resource
 681  *      - retrieve the channel offers
 682  */
 683 static int vmbus_bus_init(int irq)
 684 {
 685         int ret;
 686
 687         /* Hypervisor initialization...setup hypercall page..etc */
 688         ret = hv_init();
 689         if (ret != 0) {
 690                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 691                 return ret;
 692         }
 693
 694         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 695
 696         ret = bus_register(&hv_bus);
 697         if (ret)
 698                 goto err_cleanup;
 699
 700         hv_setup_vmbus_irq(vmbus_isr);
 701
 702         ret = hv_synic_alloc();
 703         if (ret)
 704                 goto err_alloc;
 705         /*
 706          * Initialize the per-cpu interrupt state and
 707          * connect to the host.
 708          */
 709         on_each_cpu(hv_synic_init, NULL, 1);
 710         ret = vmbus_connect();
 711         if (ret)
 712                 goto err_alloc;
 713
 714         vmbus_request_offers();
 715
 716         return 0;
 717
 718 err_alloc:
 719         hv_synic_free();
 720         hv_remove_vmbus_irq();
 721
 722         bus_unregister(&hv_bus);
 723
 724 err_cleanup:
 725         hv_cleanup();
 726
 727         return ret;
 728 }
 729
 730 /**
 731  * __vmbus_child_driver_register - Register a vmbus's driver
 732  * @drv: Pointer to driver structure you want to register
 733  * @owner: owner module of the drv
 734  * @mod_name: module name string
 735  *
 736  * Registers the given driver with Linux through the 'driver_register()' call
 737  * and sets up the hyper-v vmbus handling for this driver.
 738  * It will return the state of the 'driver_register()' call.
 739  *
 740  */
 741 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 742 {
 743         int ret;
 744
 745         pr_info("registering driver %s\n", hv_driver->name);
 746
 747         ret = vmbus_exists();
 748         if (ret < 0)
 749                 return ret;
 750
 751         hv_driver->driver.name = hv_driver->name;
 752         hv_driver->driver.owner = owner;
 753         hv_driver->driver.mod_name = mod_name;
 754         hv_driver->driver.bus = &hv_bus;
 755
 756         ret = driver_register(&hv_driver->driver);
 757
 758         return ret;
 759 }
 760 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 761
 762 /**
 763  * vmbus_driver_unregister() - Unregister a vmbus's driver
 764  * @drv: Pointer to driver structure you want to un-register
 765  *
 766  * Un-register the given driver that was previous registered with a call to
 767  * vmbus_driver_register()
 768  */
 769 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 770 {
 771         pr_info("unregistering driver %s\n", hv_driver->name);
 772
 773         if (!vmbus_exists())
 774                 driver_unregister(&hv_driver->driver);
 775 }
 776 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 777
 778 /*
 779  * vmbus_device_create - Creates and registers a new child device
 780  * on the vmbus.
 781  */
 782 struct hv_device *vmbus_device_create(uuid_le *type,
 783                                             uuid_le *instance,
 784                                             struct vmbus_channel *channel)
 785 {
 786         struct hv_device *child_device_obj;
 787
 788         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 789         if (!child_device_obj) {
 790                 pr_err("Unable to allocate device object for child device\n");
 791                 return NULL;
 792         }
 793
 794         child_device_obj->channel = channel;
 795         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 796         memcpy(&child_device_obj->dev_instance, instance,
 797                sizeof(uuid_le));
 798
 799
 800         return child_device_obj;
 801 }
 802
 803 /*
 804  * vmbus_device_register - Register the child device
 805  */
 806 int vmbus_device_register(struct hv_device *child_device_obj)
 807 {
 808         int ret = 0;
 809
 810         static atomic_t device_num = ATOMIC_INIT(0);
 811
 812         dev_set_name(&child_device_obj->device, "vmbus_0_%d",
 813                      atomic_inc_return(&device_num));
 814
 815         child_device_obj->device.bus = &hv_bus;
 816         child_device_obj->device.parent = &hv_acpi_dev->dev;
 817         child_device_obj->device.release = vmbus_device_release;
 818
 819         /*
 820          * Register with the LDM. This will kick off the driver/device
 821          * binding...which will eventually call vmbus_match() and vmbus_probe()
 822          */
 823         ret = device_register(&child_device_obj->device);
 824
 825         if (ret)
 826                 pr_err("Unable to register child device\n");
 827         else
 828                 pr_debug("child device %s registered\n",
 829                         dev_name(&child_device_obj->device));
 830
 831         return ret;
 832 }
 833
 834 /*
 835  * vmbus_device_unregister - Remove the specified child device
 836  * from the vmbus.
 837  */
 838 void vmbus_device_unregister(struct hv_device *device_obj)
 839 {
 840         pr_debug("child device %s unregistered\n",
 841                 dev_name(&device_obj->device));
 842
 843         /*
 844          * Kick off the process of unregistering the device.
 845          * This will call vmbus_remove() and eventually vmbus_device_release()
 846          */
 847         device_unregister(&device_obj->device);
 848 }
 849
 850
 851 /*
 852  * VMBUS is an acpi enumerated device. Get the the information we
 853  * need from DSDT.
 854  */
 855
 856 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
 857 {
 858         switch (res->type) {
 859         case ACPI_RESOURCE_TYPE_IRQ:
 860                 irq = res->data.irq.interrupts[0];
 861                 break;
 862
 863         case ACPI_RESOURCE_TYPE_ADDRESS64:
 864                 hyperv_mmio.start = res->data.address64.minimum;
 865                 hyperv_mmio.end = res->data.address64.maximum;
 866                 break;
 867         }
 868
 869         return AE_OK;
 870 }
 871
 872 static int vmbus_acpi_add(struct acpi_device *device)
 873 {
 874         acpi_status result;
 875         int ret_val = -ENODEV;
 876
 877         hv_acpi_dev = device;
 878
 879         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 880                                         vmbus_walk_resources, NULL);
 881
 882         if (ACPI_FAILURE(result))
 883                 goto acpi_walk_err;
 884         /*
 885          * The parent of the vmbus acpi device (Gen2 firmware) is the VMOD that
 886          * has the mmio ranges. Get that.
 887          */
 888         if (device->parent) {
 889                 result = acpi_walk_resources(device->parent->handle,
 890                                         METHOD_NAME__CRS,
 891                                         vmbus_walk_resources, NULL);
 892
 893                 if (ACPI_FAILURE(result))
 894                         goto acpi_walk_err;
 895                 if (hyperv_mmio.start && hyperv_mmio.end)
 896                         request_resource(&iomem_resource, &hyperv_mmio);
 897         }
 898         ret_val = 0;
 899
 900 acpi_walk_err:
 901         complete(&probe_event);
 902         return ret_val;
 903 }
 904
 905 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
 906         {"VMBUS", 0},
 907         {"VMBus", 0},
 908         {"", 0},
 909 };
 910 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
 911
 912 static struct acpi_driver vmbus_acpi_driver = {
 913         .name = "vmbus",
 914         .ids = vmbus_acpi_device_ids,
 915         .ops = {
 916                 .add = vmbus_acpi_add,
 917         },
 918 };
 919
 920 static int __init hv_acpi_init(void)
 921 {
 922         int ret, t;
 923
 924         if (x86_hyper != &x86_hyper_ms_hyperv)
 925                 return -ENODEV;
 926
 927         init_completion(&probe_event);
 928
 929         /*
 930          * Get irq resources first.
 931          */
 932         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 933
 934         if (ret)
 935                 return ret;
 936
 937         t = wait_for_completion_timeout(&probe_event, 5*HZ);
 938         if (t == 0) {
 939                 ret = -ETIMEDOUT;
 940                 goto cleanup;
 941         }
 942
 943         if (irq <= 0) {
 944                 ret = -ENODEV;
 945                 goto cleanup;
 946         }
 947
 948         ret = vmbus_bus_init(irq);
 949         if (ret)
 950                 goto cleanup;
 951
 952         return 0;
 953
 954 cleanup:
 955         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 956         hv_acpi_dev = NULL;
 957         return ret;
 958 }
 959
 960 static void __exit vmbus_exit(void)
 961 {
 962         hv_remove_vmbus_irq();
 963         vmbus_free_channels();
 964         bus_unregister(&hv_bus);
 965         hv_cleanup();
 966         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 967 }
 968
 969
 970 MODULE_LICENSE("GPL");
 971
 972 subsys_initcall(hv_acpi_init);
 973 module_exit(vmbus_exit);