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/irq.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/sysctl.h>
  31 #include <linux/slab.h>
  32 #include <linux/acpi.h>
  33 #include <acpi/acpi_bus.h>
  34 #include <linux/completion.h>
  35 #include <linux/hyperv.h>
  36 #include <asm/hyperv.h>
  37 #include <asm/hypervisor.h>
  38 #include "hyperv_vmbus.h"
  39
  40
  41 static struct acpi_device  *hv_acpi_dev;
  42
  43 static struct tasklet_struct msg_dpc;
  44 static struct completion probe_event;
  45 static int irq;
  46
  47 struct hv_device_info {
  48         u32 chn_id;
  49         u32 chn_state;
  50         uuid_le chn_type;
  51         uuid_le chn_instance;
  52
  53         u32 monitor_id;
  54         u32 server_monitor_pending;
  55         u32 server_monitor_latency;
  56         u32 server_monitor_conn_id;
  57         u32 client_monitor_pending;
  58         u32 client_monitor_latency;
  59         u32 client_monitor_conn_id;
  60
  61         struct hv_dev_port_info inbound;
  62         struct hv_dev_port_info outbound;
  63 };
  64
  65 static int vmbus_exists(void)
  66 {
  67         if (hv_acpi_dev == NULL)
  68                 return -ENODEV;
  69
  70         return 0;
  71 }
  72
  73
  74 static void get_channel_info(struct hv_device *device,
  75                              struct hv_device_info *info)
  76 {
  77         struct vmbus_channel_debug_info debug_info;
  78
  79         if (!device->channel)
  80                 return;
  81
  82         vmbus_get_debug_info(device->channel, &debug_info);
  83
  84         info->chn_id = debug_info.relid;
  85         info->chn_state = debug_info.state;
  86         memcpy(&info->chn_type, &debug_info.interfacetype,
  87                sizeof(uuid_le));
  88         memcpy(&info->chn_instance, &debug_info.interface_instance,
  89                sizeof(uuid_le));
  90
  91         info->monitor_id = debug_info.monitorid;
  92
  93         info->server_monitor_pending = debug_info.servermonitor_pending;
  94         info->server_monitor_latency = debug_info.servermonitor_latency;
  95         info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
  96
  97         info->client_monitor_pending = debug_info.clientmonitor_pending;
  98         info->client_monitor_latency = debug_info.clientmonitor_latency;
  99         info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
 100
 101         info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
 102         info->inbound.read_idx = debug_info.inbound.current_read_index;
 103         info->inbound.write_idx = debug_info.inbound.current_write_index;
 104         info->inbound.bytes_avail_toread =
 105                 debug_info.inbound.bytes_avail_toread;
 106         info->inbound.bytes_avail_towrite =
 107                 debug_info.inbound.bytes_avail_towrite;
 108
 109         info->outbound.int_mask =
 110                 debug_info.outbound.current_interrupt_mask;
 111         info->outbound.read_idx = debug_info.outbound.current_read_index;
 112         info->outbound.write_idx = debug_info.outbound.current_write_index;
 113         info->outbound.bytes_avail_toread =
 114                 debug_info.outbound.bytes_avail_toread;
 115         info->outbound.bytes_avail_towrite =
 116                 debug_info.outbound.bytes_avail_towrite;
 117 }
 118
 119 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 120 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 121 {
 122         int i;
 123         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 124                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 125 }
 126
 127 /*
 128  * vmbus_show_device_attr - Show the device attribute in sysfs.
 129  *
 130  * This is invoked when user does a
 131  * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
 132  */
 133 static ssize_t vmbus_show_device_attr(struct device *dev,
 134                                       struct device_attribute *dev_attr,
 135                                       char *buf)
 136 {
 137         struct hv_device *hv_dev = device_to_hv_device(dev);
 138         struct hv_device_info *device_info;
 139         char alias_name[VMBUS_ALIAS_LEN + 1];
 140         int ret = 0;
 141
 142         device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
 143         if (!device_info)
 144                 return ret;
 145
 146         get_channel_info(hv_dev, device_info);
 147
 148         if (!strcmp(dev_attr->attr.name, "class_id")) {
 149                 ret = sprintf(buf, "{%pUl}\n", device_info->chn_type.b);
 150         } else if (!strcmp(dev_attr->attr.name, "device_id")) {
 151                 ret = sprintf(buf, "{%pUl}\n", device_info->chn_instance.b);
 152         } else if (!strcmp(dev_attr->attr.name, "modalias")) {
 153                 print_alias_name(hv_dev, alias_name);
 154                 ret = sprintf(buf, "vmbus:%s\n", alias_name);
 155         } else if (!strcmp(dev_attr->attr.name, "state")) {
 156                 ret = sprintf(buf, "%d\n", device_info->chn_state);
 157         } else if (!strcmp(dev_attr->attr.name, "id")) {
 158                 ret = sprintf(buf, "%d\n", device_info->chn_id);
 159         } else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
 160                 ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
 161         } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
 162                 ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
 163         } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
 164                 ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
 165         } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
 166                 ret = sprintf(buf, "%d\n",
 167                                device_info->outbound.bytes_avail_toread);
 168         } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
 169                 ret = sprintf(buf, "%d\n",
 170                                device_info->outbound.bytes_avail_towrite);
 171         } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
 172                 ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
 173         } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
 174                 ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
 175         } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
 176                 ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
 177         } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
 178                 ret = sprintf(buf, "%d\n",
 179                                device_info->inbound.bytes_avail_toread);
 180         } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
 181                 ret = sprintf(buf, "%d\n",
 182                                device_info->inbound.bytes_avail_towrite);
 183         } else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
 184                 ret = sprintf(buf, "%d\n", device_info->monitor_id);
 185         } else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
 186                 ret = sprintf(buf, "%d\n", device_info->server_monitor_pending);
 187         } else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
 188                 ret = sprintf(buf, "%d\n", device_info->server_monitor_latency);
 189         } else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
 190                 ret = sprintf(buf, "%d\n",
 191                                device_info->server_monitor_conn_id);
 192         } else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
 193                 ret = sprintf(buf, "%d\n", device_info->client_monitor_pending);
 194         } else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
 195                 ret = sprintf(buf, "%d\n", device_info->client_monitor_latency);
 196         } else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
 197                 ret = sprintf(buf, "%d\n",
 198                                device_info->client_monitor_conn_id);
 199         }
 200
 201         kfree(device_info);
 202         return ret;
 203 }
 204
 205 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 206 static struct device_attribute vmbus_device_attrs[] = {
 207         __ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
 208         __ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
 209         __ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
 210         __ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
 211         __ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
 212         __ATTR(modalias, S_IRUGO, vmbus_show_device_attr, NULL),
 213
 214         __ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 215         __ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 216         __ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 217
 218         __ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 219         __ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 220         __ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 221
 222         __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 223         __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 224         __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 225         __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 226         __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 227
 228         __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 229         __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 230         __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 231         __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 232         __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 233         __ATTR_NULL
 234 };
 235
 236
 237 /*
 238  * vmbus_uevent - add uevent for our device
 239  *
 240  * This routine is invoked when a device is added or removed on the vmbus to
 241  * generate a uevent to udev in the userspace. The udev will then look at its
 242  * rule and the uevent generated here to load the appropriate driver
 243  *
 244  * The alias string will be of the form vmbus:guid where guid is the string
 245  * representation of the device guid (each byte of the guid will be
 246  * represented with two hex characters.
 247  */
 248 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 249 {
 250         struct hv_device *dev = device_to_hv_device(device);
 251         int ret;
 252         char alias_name[VMBUS_ALIAS_LEN + 1];
 253
 254         print_alias_name(dev, alias_name);
 255         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 256         return ret;
 257 }
 258
 259 static uuid_le null_guid;
 260
 261 static inline bool is_null_guid(const __u8 *guid)
 262 {
 263         if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 264                 return false;
 265         return true;
 266 }
 267
 268 /*
 269  * Return a matching hv_vmbus_device_id pointer.
 270  * If there is no match, return NULL.
 271  */
 272 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 273                                         const struct hv_vmbus_device_id *id,
 274                                         __u8 *guid)
 275 {
 276         for (; !is_null_guid(id->guid); id++)
 277                 if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
 278                         return id;
 279
 280         return NULL;
 281 }
 282
 283
 284
 285 /*
 286  * vmbus_match - Attempt to match the specified device to the specified driver
 287  */
 288 static int vmbus_match(struct device *device, struct device_driver *driver)
 289 {
 290         struct hv_driver *drv = drv_to_hv_drv(driver);
 291         struct hv_device *hv_dev = device_to_hv_device(device);
 292
 293         if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
 294                 return 1;
 295
 296         return 0;
 297 }
 298
 299 /*
 300  * vmbus_probe - Add the new vmbus's child device
 301  */
 302 static int vmbus_probe(struct device *child_device)
 303 {
 304         int ret = 0;
 305         struct hv_driver *drv =
 306                         drv_to_hv_drv(child_device->driver);
 307         struct hv_device *dev = device_to_hv_device(child_device);
 308         const struct hv_vmbus_device_id *dev_id;
 309
 310         dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
 311         if (drv->probe) {
 312                 ret = drv->probe(dev, dev_id);
 313                 if (ret != 0)
 314                         pr_err("probe failed for device %s (%d)\n",
 315                                dev_name(child_device), ret);
 316
 317         } else {
 318                 pr_err("probe not set for driver %s\n",
 319                        dev_name(child_device));
 320                 ret = -ENODEV;
 321         }
 322         return ret;
 323 }
 324
 325 /*
 326  * vmbus_remove - Remove a vmbus device
 327  */
 328 static int vmbus_remove(struct device *child_device)
 329 {
 330         struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
 331         struct hv_device *dev = device_to_hv_device(child_device);
 332
 333         if (drv->remove)
 334                 drv->remove(dev);
 335         else
 336                 pr_err("remove not set for driver %s\n",
 337                         dev_name(child_device));
 338
 339         return 0;
 340 }
 341
 342
 343 /*
 344  * vmbus_shutdown - Shutdown a vmbus device
 345  */
 346 static void vmbus_shutdown(struct device *child_device)
 347 {
 348         struct hv_driver *drv;
 349         struct hv_device *dev = device_to_hv_device(child_device);
 350
 351
 352         /* The device may not be attached yet */
 353         if (!child_device->driver)
 354                 return;
 355
 356         drv = drv_to_hv_drv(child_device->driver);
 357
 358         if (drv->shutdown)
 359                 drv->shutdown(dev);
 360
 361         return;
 362 }
 363
 364
 365 /*
 366  * vmbus_device_release - Final callback release of the vmbus child device
 367  */
 368 static void vmbus_device_release(struct device *device)
 369 {
 370         struct hv_device *hv_dev = device_to_hv_device(device);
 371
 372         kfree(hv_dev);
 373
 374 }
 375
 376 /* The one and only one */
 377 static struct bus_type  hv_bus = {
 378         .name =         "vmbus",
 379         .match =                vmbus_match,
 380         .shutdown =             vmbus_shutdown,
 381         .remove =               vmbus_remove,
 382         .probe =                vmbus_probe,
 383         .uevent =               vmbus_uevent,
 384         .dev_attrs =    vmbus_device_attrs,
 385 };
 386
 387 static const char *driver_name = "hyperv";
 388
 389
 390 struct onmessage_work_context {
 391         struct work_struct work;
 392         struct hv_message msg;
 393 };
 394
 395 static void vmbus_onmessage_work(struct work_struct *work)
 396 {
 397         struct onmessage_work_context *ctx;
 398
 399         ctx = container_of(work, struct onmessage_work_context,
 400                            work);
 401         vmbus_onmessage(&ctx->msg);
 402         kfree(ctx);
 403 }
 404
 405 static void vmbus_on_msg_dpc(unsigned long data)
 406 {
 407         int cpu = smp_processor_id();
 408         void *page_addr = hv_context.synic_message_page[cpu];
 409         struct hv_message *msg = (struct hv_message *)page_addr +
 410                                   VMBUS_MESSAGE_SINT;
 411         struct onmessage_work_context *ctx;
 412
 413         while (1) {
 414                 if (msg->header.message_type == HVMSG_NONE) {
 415                         /* no msg */
 416                         break;
 417                 } else {
 418                         ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 419                         if (ctx == NULL)
 420                                 continue;
 421                         INIT_WORK(&ctx->work, vmbus_onmessage_work);
 422                         memcpy(&ctx->msg, msg, sizeof(*msg));
 423                         queue_work(vmbus_connection.work_queue, &ctx->work);
 424                 }
 425
 426                 msg->header.message_type = HVMSG_NONE;
 427
 428                 /*
 429                  * Make sure the write to MessageType (ie set to
 430                  * HVMSG_NONE) happens before we read the
 431                  * MessagePending and EOMing. Otherwise, the EOMing
 432                  * will not deliver any more messages since there is
 433                  * no empty slot
 434                  */
 435                 smp_mb();
 436
 437                 if (msg->header.message_flags.msg_pending) {
 438                         /*
 439                          * This will cause message queue rescan to
 440                          * possibly deliver another msg from the
 441                          * hypervisor
 442                          */
 443                         wrmsrl(HV_X64_MSR_EOM, 0);
 444                 }
 445         }
 446 }
 447
 448 static irqreturn_t vmbus_isr(int irq, void *dev_id)
 449 {
 450         int cpu = smp_processor_id();
 451         void *page_addr;
 452         struct hv_message *msg;
 453         union hv_synic_event_flags *event;
 454         bool handled = false;
 455
 456         /*
 457          * Check for events before checking for messages. This is the order
 458          * in which events and messages are checked in Windows guests on
 459          * Hyper-V, and the Windows team suggested we do the same.
 460          */
 461
 462         if ((vmbus_proto_version == VERSION_WS2008) ||
 463                 (vmbus_proto_version == VERSION_WIN7)) {
 464
 465                 page_addr = hv_context.synic_event_page[cpu];
 466                 event = (union hv_synic_event_flags *)page_addr +
 467                                          VMBUS_MESSAGE_SINT;
 468
 469                 /* Since we are a child, we only need to check bit 0 */
 470                 if (sync_test_and_clear_bit(0,
 471                         (unsigned long *) &event->flags32[0])) {
 472                         handled = true;
 473                 }
 474         } else {
 475                 /*
 476                  * Our host is win8 or above. The signaling mechanism
 477                  * has changed and we can directly look at the event page.
 478                  * If bit n is set then we have an interrup on the channel
 479                  * whose id is n.
 480                  */
 481                 handled = true;
 482         }
 483
 484         if (handled)
 485                 tasklet_schedule(hv_context.event_dpc[cpu]);
 486
 487
 488         page_addr = hv_context.synic_message_page[cpu];
 489         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 490
 491         /* Check if there are actual msgs to be processed */
 492         if (msg->header.message_type != HVMSG_NONE) {
 493                 handled = true;
 494                 tasklet_schedule(&msg_dpc);
 495         }
 496
 497         if (handled)
 498                 return IRQ_HANDLED;
 499         else
 500                 return IRQ_NONE;
 501 }
 502
 503 /*
 504  * vmbus_bus_init -Main vmbus driver initialization routine.
 505  *
 506  * Here, we
 507  *      - initialize the vmbus driver context
 508  *      - invoke the vmbus hv main init routine
 509  *      - get the irq resource
 510  *      - retrieve the channel offers
 511  */
 512 static int vmbus_bus_init(int irq)
 513 {
 514         int ret;
 515         unsigned int vector;
 516
 517         /* Hypervisor initialization...setup hypercall page..etc */
 518         ret = hv_init();
 519         if (ret != 0) {
 520                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 521                 return ret;
 522         }
 523
 524         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 525
 526         ret = bus_register(&hv_bus);
 527         if (ret)
 528                 goto err_cleanup;
 529
 530         ret = request_irq(irq, vmbus_isr, 0, driver_name, hv_acpi_dev);
 531
 532         if (ret != 0) {
 533                 pr_err("Unable to request IRQ %d\n",
 534                            irq);
 535                 goto err_unregister;
 536         }
 537
 538         vector = IRQ0_VECTOR + irq;
 539
 540         /*
 541          * Notify the hypervisor of our irq and
 542          * connect to the host.
 543          */
 544         on_each_cpu(hv_synic_init, (void *)&vector, 1);
 545         ret = vmbus_connect();
 546         if (ret)
 547                 goto err_irq;
 548
 549         vmbus_request_offers();
 550
 551         return 0;
 552
 553 err_irq:
 554         free_irq(irq, hv_acpi_dev);
 555
 556 err_unregister:
 557         bus_unregister(&hv_bus);
 558
 559 err_cleanup:
 560         hv_cleanup();
 561
 562         return ret;
 563 }
 564
 565 /**
 566  * __vmbus_child_driver_register - Register a vmbus's driver
 567  * @drv: Pointer to driver structure you want to register
 568  * @owner: owner module of the drv
 569  * @mod_name: module name string
 570  *
 571  * Registers the given driver with Linux through the 'driver_register()' call
 572  * and sets up the hyper-v vmbus handling for this driver.
 573  * It will return the state of the 'driver_register()' call.
 574  *
 575  */
 576 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 577 {
 578         int ret;
 579
 580         pr_info("registering driver %s\n", hv_driver->name);
 581
 582         ret = vmbus_exists();
 583         if (ret < 0)
 584                 return ret;
 585
 586         hv_driver->driver.name = hv_driver->name;
 587         hv_driver->driver.owner = owner;
 588         hv_driver->driver.mod_name = mod_name;
 589         hv_driver->driver.bus = &hv_bus;
 590
 591         ret = driver_register(&hv_driver->driver);
 592
 593         return ret;
 594 }
 595 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 596
 597 /**
 598  * vmbus_driver_unregister() - Unregister a vmbus's driver
 599  * @drv: Pointer to driver structure you want to un-register
 600  *
 601  * Un-register the given driver that was previous registered with a call to
 602  * vmbus_driver_register()
 603  */
 604 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 605 {
 606         pr_info("unregistering driver %s\n", hv_driver->name);
 607
 608         if (!vmbus_exists())
 609                 driver_unregister(&hv_driver->driver);
 610 }
 611 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 612
 613 /*
 614  * vmbus_device_create - Creates and registers a new child device
 615  * on the vmbus.
 616  */
 617 struct hv_device *vmbus_device_create(uuid_le *type,
 618                                             uuid_le *instance,
 619                                             struct vmbus_channel *channel)
 620 {
 621         struct hv_device *child_device_obj;
 622
 623         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 624         if (!child_device_obj) {
 625                 pr_err("Unable to allocate device object for child device\n");
 626                 return NULL;
 627         }
 628
 629         child_device_obj->channel = channel;
 630         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 631         memcpy(&child_device_obj->dev_instance, instance,
 632                sizeof(uuid_le));
 633
 634
 635         return child_device_obj;
 636 }
 637
 638 /*
 639  * vmbus_device_register - Register the child device
 640  */
 641 int vmbus_device_register(struct hv_device *child_device_obj)
 642 {
 643         int ret = 0;
 644
 645         static atomic_t device_num = ATOMIC_INIT(0);
 646
 647         dev_set_name(&child_device_obj->device, "vmbus_0_%d",
 648                      atomic_inc_return(&device_num));
 649
 650         child_device_obj->device.bus = &hv_bus;
 651         child_device_obj->device.parent = &hv_acpi_dev->dev;
 652         child_device_obj->device.release = vmbus_device_release;
 653
 654         /*
 655          * Register with the LDM. This will kick off the driver/device
 656          * binding...which will eventually call vmbus_match() and vmbus_probe()
 657          */
 658         ret = device_register(&child_device_obj->device);
 659
 660         if (ret)
 661                 pr_err("Unable to register child device\n");
 662         else
 663                 pr_info("child device %s registered\n",
 664                         dev_name(&child_device_obj->device));
 665
 666         return ret;
 667 }
 668
 669 /*
 670  * vmbus_device_unregister - Remove the specified child device
 671  * from the vmbus.
 672  */
 673 void vmbus_device_unregister(struct hv_device *device_obj)
 674 {
 675         /*
 676          * Kick off the process of unregistering the device.
 677          * This will call vmbus_remove() and eventually vmbus_device_release()
 678          */
 679         device_unregister(&device_obj->device);
 680
 681         pr_info("child device %s unregistered\n",
 682                 dev_name(&device_obj->device));
 683 }
 684
 685
 686 /*
 687  * VMBUS is an acpi enumerated device. Get the the IRQ information
 688  * from DSDT.
 689  */
 690
 691 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
 692 {
 693
 694         if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
 695                 struct acpi_resource_irq *irqp;
 696                 irqp = &res->data.irq;
 697
 698                 *((unsigned int *)irq) = irqp->interrupts[0];
 699         }
 700
 701         return AE_OK;
 702 }
 703
 704 static int vmbus_acpi_add(struct acpi_device *device)
 705 {
 706         acpi_status result;
 707
 708         hv_acpi_dev = device;
 709
 710         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 711                                         vmbus_walk_resources, &irq);
 712
 713         if (ACPI_FAILURE(result)) {
 714                 complete(&probe_event);
 715                 return -ENODEV;
 716         }
 717         complete(&probe_event);
 718         return 0;
 719 }
 720
 721 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
 722         {"VMBUS", 0},
 723         {"VMBus", 0},
 724         {"", 0},
 725 };
 726 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
 727
 728 static struct acpi_driver vmbus_acpi_driver = {
 729         .name = "vmbus",
 730         .ids = vmbus_acpi_device_ids,
 731         .ops = {
 732                 .add = vmbus_acpi_add,
 733         },
 734 };
 735
 736 static int __init hv_acpi_init(void)
 737 {
 738         int ret, t;
 739
 740         if (x86_hyper != &x86_hyper_ms_hyperv)
 741                 return -ENODEV;
 742
 743         init_completion(&probe_event);
 744
 745         /*
 746          * Get irq resources first.
 747          */
 748
 749         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 750
 751         if (ret)
 752                 return ret;
 753
 754         t = wait_for_completion_timeout(&probe_event, 5*HZ);
 755         if (t == 0) {
 756                 ret = -ETIMEDOUT;
 757                 goto cleanup;
 758         }
 759
 760         if (irq <= 0) {
 761                 ret = -ENODEV;
 762                 goto cleanup;
 763         }
 764
 765         ret = vmbus_bus_init(irq);
 766         if (ret)
 767                 goto cleanup;
 768
 769         return 0;
 770
 771 cleanup:
 772         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 773         hv_acpi_dev = NULL;
 774         return ret;
 775 }
 776
 777 static void __exit vmbus_exit(void)
 778 {
 779
 780         free_irq(irq, hv_acpi_dev);
 781         vmbus_free_channels();
 782         bus_unregister(&hv_bus);
 783         hv_cleanup();
 784         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 785 }
 786
 787
 788 MODULE_LICENSE("GPL");
 789 MODULE_VERSION(HV_DRV_VERSION);
 790
 791 subsys_initcall(hv_acpi_init);
 792 module_exit(vmbus_exit);