Pileus Git - ~andy/linux/blob - drivers/staging/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
  36 #include "hyperv.h"
  37 #include "hyperv_vmbus.h"
  38
  39
  40 static struct acpi_device  *hv_acpi_dev;
  41
  42 static struct tasklet_struct msg_dpc;
  43 static struct tasklet_struct event_dpc;
  44
  45 unsigned int vmbus_loglevel = (ALL_MODULES << 16 | INFO_LVL);
  46 EXPORT_SYMBOL(vmbus_loglevel);
  47
  48 static struct completion probe_event;
  49 static int irq;
  50
  51 static void get_channel_info(struct hv_device *device,
  52                              struct hv_device_info *info)
  53 {
  54         struct vmbus_channel_debug_info debug_info;
  55
  56         if (!device->channel)
  57                 return;
  58
  59         vmbus_get_debug_info(device->channel, &debug_info);
  60
  61         info->chn_id = debug_info.relid;
  62         info->chn_state = debug_info.state;
  63         memcpy(&info->chn_type, &debug_info.interfacetype,
  64                sizeof(uuid_le));
  65         memcpy(&info->chn_instance, &debug_info.interface_instance,
  66                sizeof(uuid_le));
  67
  68         info->monitor_id = debug_info.monitorid;
  69
  70         info->server_monitor_pending = debug_info.servermonitor_pending;
  71         info->server_monitor_latency = debug_info.servermonitor_latency;
  72         info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
  73
  74         info->client_monitor_pending = debug_info.clientmonitor_pending;
  75         info->client_monitor_latency = debug_info.clientmonitor_latency;
  76         info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
  77
  78         info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
  79         info->inbound.read_idx = debug_info.inbound.current_read_index;
  80         info->inbound.write_idx = debug_info.inbound.current_write_index;
  81         info->inbound.bytes_avail_toread =
  82                 debug_info.inbound.bytes_avail_toread;
  83         info->inbound.bytes_avail_towrite =
  84                 debug_info.inbound.bytes_avail_towrite;
  85
  86         info->outbound.int_mask =
  87                 debug_info.outbound.current_interrupt_mask;
  88         info->outbound.read_idx = debug_info.outbound.current_read_index;
  89         info->outbound.write_idx = debug_info.outbound.current_write_index;
  90         info->outbound.bytes_avail_toread =
  91                 debug_info.outbound.bytes_avail_toread;
  92         info->outbound.bytes_avail_towrite =
  93                 debug_info.outbound.bytes_avail_towrite;
  94 }
  95
  96 /*
  97  * vmbus_show_device_attr - Show the device attribute in sysfs.
  98  *
  99  * This is invoked when user does a
 100  * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
 101  */
 102 static ssize_t vmbus_show_device_attr(struct device *dev,
 103                                       struct device_attribute *dev_attr,
 104                                       char *buf)
 105 {
 106         struct hv_device *hv_dev = device_to_hv_device(dev);
 107         struct hv_device_info device_info;
 108
 109         memset(&device_info, 0, sizeof(struct hv_device_info));
 110
 111         get_channel_info(hv_dev, &device_info);
 112
 113         if (!strcmp(dev_attr->attr.name, "class_id")) {
 114                 return sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
 115                                "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
 116                                device_info.chn_type.b[3],
 117                                device_info.chn_type.b[2],
 118                                device_info.chn_type.b[1],
 119                                device_info.chn_type.b[0],
 120                                device_info.chn_type.b[5],
 121                                device_info.chn_type.b[4],
 122                                device_info.chn_type.b[7],
 123                                device_info.chn_type.b[6],
 124                                device_info.chn_type.b[8],
 125                                device_info.chn_type.b[9],
 126                                device_info.chn_type.b[10],
 127                                device_info.chn_type.b[11],
 128                                device_info.chn_type.b[12],
 129                                device_info.chn_type.b[13],
 130                                device_info.chn_type.b[14],
 131                                device_info.chn_type.b[15]);
 132         } else if (!strcmp(dev_attr->attr.name, "device_id")) {
 133                 return sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
 134                                "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
 135                                device_info.chn_instance.b[3],
 136                                device_info.chn_instance.b[2],
 137                                device_info.chn_instance.b[1],
 138                                device_info.chn_instance.b[0],
 139                                device_info.chn_instance.b[5],
 140                                device_info.chn_instance.b[4],
 141                                device_info.chn_instance.b[7],
 142                                device_info.chn_instance.b[6],
 143                                device_info.chn_instance.b[8],
 144                                device_info.chn_instance.b[9],
 145                                device_info.chn_instance.b[10],
 146                                device_info.chn_instance.b[11],
 147                                device_info.chn_instance.b[12],
 148                                device_info.chn_instance.b[13],
 149                                device_info.chn_instance.b[14],
 150                                device_info.chn_instance.b[15]);
 151         } else if (!strcmp(dev_attr->attr.name, "state")) {
 152                 return sprintf(buf, "%d\n", device_info.chn_state);
 153         } else if (!strcmp(dev_attr->attr.name, "id")) {
 154                 return sprintf(buf, "%d\n", device_info.chn_id);
 155         } else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
 156                 return sprintf(buf, "%d\n", device_info.outbound.int_mask);
 157         } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
 158                 return sprintf(buf, "%d\n", device_info.outbound.read_idx);
 159         } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
 160                 return sprintf(buf, "%d\n", device_info.outbound.write_idx);
 161         } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
 162                 return sprintf(buf, "%d\n",
 163                                device_info.outbound.bytes_avail_toread);
 164         } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
 165                 return sprintf(buf, "%d\n",
 166                                device_info.outbound.bytes_avail_towrite);
 167         } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
 168                 return sprintf(buf, "%d\n", device_info.inbound.int_mask);
 169         } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
 170                 return sprintf(buf, "%d\n", device_info.inbound.read_idx);
 171         } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
 172                 return sprintf(buf, "%d\n", device_info.inbound.write_idx);
 173         } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
 174                 return sprintf(buf, "%d\n",
 175                                device_info.inbound.bytes_avail_toread);
 176         } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
 177                 return sprintf(buf, "%d\n",
 178                                device_info.inbound.bytes_avail_towrite);
 179         } else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
 180                 return sprintf(buf, "%d\n", device_info.monitor_id);
 181         } else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
 182                 return sprintf(buf, "%d\n", device_info.server_monitor_pending);
 183         } else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
 184                 return sprintf(buf, "%d\n", device_info.server_monitor_latency);
 185         } else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
 186                 return sprintf(buf, "%d\n",
 187                                device_info.server_monitor_conn_id);
 188         } else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
 189                 return sprintf(buf, "%d\n", device_info.client_monitor_pending);
 190         } else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
 191                 return sprintf(buf, "%d\n", device_info.client_monitor_latency);
 192         } else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
 193                 return sprintf(buf, "%d\n",
 194                                device_info.client_monitor_conn_id);
 195         } else {
 196                 return 0;
 197         }
 198 }
 199
 200 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 201 static struct device_attribute vmbus_device_attrs[] = {
 202         __ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
 203         __ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
 204         __ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
 205         __ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
 206         __ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
 207
 208         __ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 209         __ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 210         __ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 211
 212         __ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 213         __ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 214         __ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 215
 216         __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 217         __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 218         __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 219         __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 220         __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 221
 222         __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 223         __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 224         __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 225         __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 226         __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 227         __ATTR_NULL
 228 };
 229
 230
 231 /*
 232  * vmbus_uevent - add uevent for our device
 233  *
 234  * This routine is invoked when a device is added or removed on the vmbus to
 235  * generate a uevent to udev in the userspace. The udev will then look at its
 236  * rule and the uevent generated here to load the appropriate driver
 237  *
 238  * The alias string will be of the form vmbus:guid where guid is the string
 239  * representation of the device guid (each byte of the guid will be
 240  * represented with two hex characters.
 241  */
 242 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 243 {
 244         struct hv_device *dev = device_to_hv_device(device);
 245         int i, ret;
 246         char alias_name[((sizeof((struct hv_vmbus_device_id *)0)->guid) + 1) * 2];
 247
 248         for (i = 0; i < ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2); i += 2)
 249                 sprintf(&alias_name[i], "%02x", dev->dev_type.b[i/2]);
 250
 251         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 252         return ret;
 253 }
 254
 255 static uuid_le null_guid;
 256
 257 static inline bool is_null_guid(const __u8 *guid)
 258 {
 259         if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 260                 return false;
 261         return true;
 262 }
 263
 264
 265 /*
 266  * vmbus_match - Attempt to match the specified device to the specified driver
 267  */
 268 static int vmbus_match(struct device *device, struct device_driver *driver)
 269 {
 270         struct hv_driver *drv = drv_to_hv_drv(driver);
 271         struct hv_device *hv_dev = device_to_hv_device(device);
 272         const struct hv_vmbus_device_id *id_array = drv->id_table;
 273
 274         for (; !is_null_guid(id_array->guid); id_array++)
 275                 if (!memcmp(&id_array->guid, &hv_dev->dev_type.b,
 276                                 sizeof(uuid_le)))
 277                         return 1;
 278
 279         return 0;
 280 }
 281
 282 /*
 283  * vmbus_probe - Add the new vmbus's child device
 284  */
 285 static int vmbus_probe(struct device *child_device)
 286 {
 287         int ret = 0;
 288         struct hv_driver *drv =
 289                         drv_to_hv_drv(child_device->driver);
 290         struct hv_device *dev = device_to_hv_device(child_device);
 291
 292         if (drv->probe) {
 293                 ret = drv->probe(dev);
 294                 if (ret != 0)
 295                         pr_err("probe failed for device %s (%d)\n",
 296                                dev_name(child_device), ret);
 297
 298         } else {
 299                 pr_err("probe not set for driver %s\n",
 300                        dev_name(child_device));
 301                 ret = -ENODEV;
 302         }
 303         return ret;
 304 }
 305
 306 /*
 307  * vmbus_remove - Remove a vmbus device
 308  */
 309 static int vmbus_remove(struct device *child_device)
 310 {
 311         int ret;
 312         struct hv_driver *drv;
 313
 314         struct hv_device *dev = device_to_hv_device(child_device);
 315
 316         if (child_device->driver) {
 317                 drv = drv_to_hv_drv(child_device->driver);
 318
 319                 if (drv->remove) {
 320                         ret = drv->remove(dev);
 321                 } else {
 322                         pr_err("remove not set for driver %s\n",
 323                                 dev_name(child_device));
 324                         ret = -ENODEV;
 325                 }
 326         }
 327
 328         return 0;
 329 }
 330
 331
 332 /*
 333  * vmbus_shutdown - Shutdown a vmbus device
 334  */
 335 static void vmbus_shutdown(struct device *child_device)
 336 {
 337         struct hv_driver *drv;
 338         struct hv_device *dev = device_to_hv_device(child_device);
 339
 340
 341         /* The device may not be attached yet */
 342         if (!child_device->driver)
 343                 return;
 344
 345         drv = drv_to_hv_drv(child_device->driver);
 346
 347         if (drv->shutdown)
 348                 drv->shutdown(dev);
 349
 350         return;
 351 }
 352
 353
 354 /*
 355  * vmbus_device_release - Final callback release of the vmbus child device
 356  */
 357 static void vmbus_device_release(struct device *device)
 358 {
 359         struct hv_device *hv_dev = device_to_hv_device(device);
 360
 361         kfree(hv_dev);
 362
 363 }
 364
 365 /* The one and only one */
 366 static struct bus_type  hv_bus = {
 367         .name =         "vmbus",
 368         .match =                vmbus_match,
 369         .shutdown =             vmbus_shutdown,
 370         .remove =               vmbus_remove,
 371         .probe =                vmbus_probe,
 372         .uevent =               vmbus_uevent,
 373         .dev_attrs =    vmbus_device_attrs,
 374 };
 375
 376 static const char *driver_name = "hyperv";
 377
 378
 379 struct onmessage_work_context {
 380         struct work_struct work;
 381         struct hv_message msg;
 382 };
 383
 384 static void vmbus_onmessage_work(struct work_struct *work)
 385 {
 386         struct onmessage_work_context *ctx;
 387
 388         ctx = container_of(work, struct onmessage_work_context,
 389                            work);
 390         vmbus_onmessage(&ctx->msg);
 391         kfree(ctx);
 392 }
 393
 394 /*
 395  * vmbus_on_msg_dpc - DPC routine to handle messages from the hypervisior
 396  */
 397 static void vmbus_on_msg_dpc(unsigned long data)
 398 {
 399         int cpu = smp_processor_id();
 400         void *page_addr = hv_context.synic_message_page[cpu];
 401         struct hv_message *msg = (struct hv_message *)page_addr +
 402                                   VMBUS_MESSAGE_SINT;
 403         struct onmessage_work_context *ctx;
 404
 405         while (1) {
 406                 if (msg->header.message_type == HVMSG_NONE) {
 407                         /* no msg */
 408                         break;
 409                 } else {
 410                         ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 411                         if (ctx == NULL)
 412                                 continue;
 413                         INIT_WORK(&ctx->work, vmbus_onmessage_work);
 414                         memcpy(&ctx->msg, msg, sizeof(*msg));
 415                         queue_work(vmbus_connection.work_queue, &ctx->work);
 416                 }
 417
 418                 msg->header.message_type = HVMSG_NONE;
 419
 420                 /*
 421                  * Make sure the write to MessageType (ie set to
 422                  * HVMSG_NONE) happens before we read the
 423                  * MessagePending and EOMing. Otherwise, the EOMing
 424                  * will not deliver any more messages since there is
 425                  * no empty slot
 426                  */
 427                 smp_mb();
 428
 429                 if (msg->header.message_flags.msg_pending) {
 430                         /*
 431                          * This will cause message queue rescan to
 432                          * possibly deliver another msg from the
 433                          * hypervisor
 434                          */
 435                         wrmsrl(HV_X64_MSR_EOM, 0);
 436                 }
 437         }
 438 }
 439
 440 /*
 441  * vmbus_on_isr - ISR routine
 442  */
 443 static int vmbus_on_isr(void)
 444 {
 445         int ret = 0;
 446         int cpu = smp_processor_id();
 447         void *page_addr;
 448         struct hv_message *msg;
 449         union hv_synic_event_flags *event;
 450
 451         page_addr = hv_context.synic_message_page[cpu];
 452         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 453
 454         /* Check if there are actual msgs to be process */
 455         if (msg->header.message_type != HVMSG_NONE)
 456                 ret |= 0x1;
 457
 458         page_addr = hv_context.synic_event_page[cpu];
 459         event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
 460
 461         /* Since we are a child, we only need to check bit 0 */
 462         if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0]))
 463                 ret |= 0x2;
 464
 465         return ret;
 466 }
 467
 468
 469 static irqreturn_t vmbus_isr(int irq, void *dev_id)
 470 {
 471         int ret;
 472
 473         ret = vmbus_on_isr();
 474
 475         /* Schedules a dpc if necessary */
 476         if (ret > 0) {
 477                 if (test_bit(0, (unsigned long *)&ret))
 478                         tasklet_schedule(&msg_dpc);
 479
 480                 if (test_bit(1, (unsigned long *)&ret))
 481                         tasklet_schedule(&event_dpc);
 482
 483                 return IRQ_HANDLED;
 484         } else {
 485                 return IRQ_NONE;
 486         }
 487 }
 488
 489 /*
 490  * vmbus_bus_init -Main vmbus driver initialization routine.
 491  *
 492  * Here, we
 493  *      - initialize the vmbus driver context
 494  *      - invoke the vmbus hv main init routine
 495  *      - get the irq resource
 496  *      - retrieve the channel offers
 497  */
 498 static int vmbus_bus_init(int irq)
 499 {
 500         int ret;
 501         unsigned int vector;
 502
 503         /* Hypervisor initialization...setup hypercall page..etc */
 504         ret = hv_init();
 505         if (ret != 0) {
 506                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 507                 return ret;
 508         }
 509
 510         /* Initialize the bus context */
 511         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 512         tasklet_init(&event_dpc, vmbus_on_event, 0);
 513
 514         /* Now, register the bus  with LDM */
 515         ret = bus_register(&hv_bus);
 516         if (ret)
 517                 return ret;
 518
 519         /* Get the interrupt resource */
 520         ret = request_irq(irq, vmbus_isr, IRQF_SAMPLE_RANDOM,
 521                         driver_name, hv_acpi_dev);
 522
 523         if (ret != 0) {
 524                 pr_err("Unable to request IRQ %d\n",
 525                            irq);
 526
 527                 bus_unregister(&hv_bus);
 528
 529                 return ret;
 530         }
 531
 532         vector = IRQ0_VECTOR + irq;
 533
 534         /*
 535          * Notify the hypervisor of our irq and
 536          * connect to the host.
 537          */
 538         on_each_cpu(hv_synic_init, (void *)&vector, 1);
 539         ret = vmbus_connect();
 540         if (ret) {
 541                 free_irq(irq, hv_acpi_dev);
 542                 bus_unregister(&hv_bus);
 543                 return ret;
 544         }
 545
 546
 547         vmbus_request_offers();
 548
 549         return 0;
 550 }
 551
 552 /**
 553  * __vmbus_child_driver_register - Register a vmbus's driver
 554  * @drv: Pointer to driver structure you want to register
 555  * @owner: owner module of the drv
 556  * @mod_name: module name string
 557  *
 558  * Registers the given driver with Linux through the 'driver_register()' call
 559  * and sets up the hyper-v vmbus handling for this driver.
 560  * It will return the state of the 'driver_register()' call.
 561  *
 562  */
 563 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 564 {
 565         int ret;
 566
 567         pr_info("registering driver %s\n", hv_driver->name);
 568
 569         hv_driver->driver.name = hv_driver->name;
 570         hv_driver->driver.owner = owner;
 571         hv_driver->driver.mod_name = mod_name;
 572         hv_driver->driver.bus = &hv_bus;
 573
 574         ret = driver_register(&hv_driver->driver);
 575
 576         vmbus_request_offers();
 577
 578         return ret;
 579 }
 580 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 581
 582 /**
 583  * vmbus_driver_unregister() - Unregister a vmbus's driver
 584  * @drv: Pointer to driver structure you want to un-register
 585  *
 586  * Un-register the given driver that was previous registered with a call to
 587  * vmbus_driver_register()
 588  */
 589 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 590 {
 591         pr_info("unregistering driver %s\n", hv_driver->name);
 592
 593         driver_unregister(&hv_driver->driver);
 594
 595 }
 596 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 597
 598 /*
 599  * vmbus_child_device_create - Creates and registers a new child device
 600  * on the vmbus.
 601  */
 602 struct hv_device *vmbus_child_device_create(uuid_le *type,
 603                                             uuid_le *instance,
 604                                             struct vmbus_channel *channel)
 605 {
 606         struct hv_device *child_device_obj;
 607
 608         /* Allocate the new child device */
 609         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 610         if (!child_device_obj) {
 611                 pr_err("Unable to allocate device object for child device\n");
 612                 return NULL;
 613         }
 614
 615         child_device_obj->channel = channel;
 616         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 617         memcpy(&child_device_obj->dev_instance, instance,
 618                sizeof(uuid_le));
 619
 620
 621         return child_device_obj;
 622 }
 623
 624 /*
 625  * vmbus_child_device_register - Register the child device
 626  */
 627 int vmbus_child_device_register(struct hv_device *child_device_obj)
 628 {
 629         int ret = 0;
 630
 631         static atomic_t device_num = ATOMIC_INIT(0);
 632
 633         /* Set the device name. Otherwise, device_register() will fail. */
 634         dev_set_name(&child_device_obj->device, "vmbus_0_%d",
 635                      atomic_inc_return(&device_num));
 636
 637         /* The new device belongs to this bus */
 638         child_device_obj->device.bus = &hv_bus; /* device->dev.bus; */
 639         child_device_obj->device.parent = &hv_acpi_dev->dev;
 640         child_device_obj->device.release = vmbus_device_release;
 641
 642         /*
 643          * Register with the LDM. This will kick off the driver/device
 644          * binding...which will eventually call vmbus_match() and vmbus_probe()
 645          */
 646         ret = device_register(&child_device_obj->device);
 647
 648         if (ret)
 649                 pr_err("Unable to register child device\n");
 650         else
 651                 pr_info("child device %s registered\n",
 652                         dev_name(&child_device_obj->device));
 653
 654         return ret;
 655 }
 656
 657 /*
 658  * vmbus_child_device_unregister - Remove the specified child device
 659  * from the vmbus.
 660  */
 661 void vmbus_child_device_unregister(struct hv_device *device_obj)
 662 {
 663         /*
 664          * Kick off the process of unregistering the device.
 665          * This will call vmbus_remove() and eventually vmbus_device_release()
 666          */
 667         device_unregister(&device_obj->device);
 668
 669         pr_info("child device %s unregistered\n",
 670                 dev_name(&device_obj->device));
 671 }
 672
 673
 674 /*
 675  * VMBUS is an acpi enumerated device. Get the the IRQ information
 676  * from DSDT.
 677  */
 678
 679 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
 680 {
 681
 682         if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
 683                 struct acpi_resource_irq *irqp;
 684                 irqp = &res->data.irq;
 685
 686                 *((unsigned int *)irq) = irqp->interrupts[0];
 687         }
 688
 689         return AE_OK;
 690 }
 691
 692 static int vmbus_acpi_add(struct acpi_device *device)
 693 {
 694         acpi_status result;
 695
 696         hv_acpi_dev = device;
 697
 698         result =
 699         acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 700                         vmbus_walk_resources, &irq);
 701
 702         if (ACPI_FAILURE(result)) {
 703                 complete(&probe_event);
 704                 return -ENODEV;
 705         }
 706         complete(&probe_event);
 707         return 0;
 708 }
 709
 710 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
 711         {"VMBUS", 0},
 712         {"VMBus", 0},
 713         {"", 0},
 714 };
 715 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
 716
 717 static struct acpi_driver vmbus_acpi_driver = {
 718         .name = "vmbus",
 719         .ids = vmbus_acpi_device_ids,
 720         .ops = {
 721                 .add = vmbus_acpi_add,
 722         },
 723 };
 724
 725 static int __init hv_acpi_init(void)
 726 {
 727         int ret, t;
 728
 729         init_completion(&probe_event);
 730
 731         /*
 732          * Get irq resources first.
 733          */
 734
 735         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 736
 737         if (ret)
 738                 return ret;
 739
 740         t = wait_for_completion_timeout(&probe_event, 5*HZ);
 741         if (t == 0) {
 742                 ret = -ETIMEDOUT;
 743                 goto cleanup;
 744         }
 745
 746         if (irq <= 0) {
 747                 ret = -ENODEV;
 748                 goto cleanup;
 749         }
 750
 751         ret = vmbus_bus_init(irq);
 752         if (ret)
 753                 goto cleanup;
 754
 755         return 0;
 756
 757 cleanup:
 758         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 759         return ret;
 760 }
 761
 762
 763 MODULE_LICENSE("GPL");
 764 MODULE_VERSION(HV_DRV_VERSION);
 765 module_param(vmbus_loglevel, int, S_IRUGO|S_IWUSR);
 766
 767 module_init(hv_acpi_init);