linux/drivers/hv/vmbus_drv.c
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   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 <linux/kernel_stat.h>
  37#include <asm/hyperv.h>
  38#include <asm/hypervisor.h>
  39#include <asm/mshyperv.h>
  40#include "hyperv_vmbus.h"
  41
  42
  43static struct acpi_device  *hv_acpi_dev;
  44
  45static struct tasklet_struct msg_dpc;
  46static struct completion probe_event;
  47static int irq;
  48
  49struct hv_device_info {
  50        u32 chn_id;
  51        u32 chn_state;
  52        uuid_le chn_type;
  53        uuid_le chn_instance;
  54
  55        u32 monitor_id;
  56        u32 server_monitor_pending;
  57        u32 server_monitor_latency;
  58        u32 server_monitor_conn_id;
  59        u32 client_monitor_pending;
  60        u32 client_monitor_latency;
  61        u32 client_monitor_conn_id;
  62
  63        struct hv_dev_port_info inbound;
  64        struct hv_dev_port_info outbound;
  65};
  66
  67static int vmbus_exists(void)
  68{
  69        if (hv_acpi_dev == NULL)
  70                return -ENODEV;
  71
  72        return 0;
  73}
  74
  75
  76static void get_channel_info(struct hv_device *device,
  77                             struct hv_device_info *info)
  78{
  79        struct vmbus_channel_debug_info debug_info;
  80
  81        if (!device->channel)
  82                return;
  83
  84        vmbus_get_debug_info(device->channel, &debug_info);
  85
  86        info->chn_id = debug_info.relid;
  87        info->chn_state = debug_info.state;
  88        memcpy(&info->chn_type, &debug_info.interfacetype,
  89               sizeof(uuid_le));
  90        memcpy(&info->chn_instance, &debug_info.interface_instance,
  91               sizeof(uuid_le));
  92
  93        info->monitor_id = debug_info.monitorid;
  94
  95        info->server_monitor_pending = debug_info.servermonitor_pending;
  96        info->server_monitor_latency = debug_info.servermonitor_latency;
  97        info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
  98
  99        info->client_monitor_pending = debug_info.clientmonitor_pending;
 100        info->client_monitor_latency = debug_info.clientmonitor_latency;
 101        info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
 102
 103        info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
 104        info->inbound.read_idx = debug_info.inbound.current_read_index;
 105        info->inbound.write_idx = debug_info.inbound.current_write_index;
 106        info->inbound.bytes_avail_toread =
 107                debug_info.inbound.bytes_avail_toread;
 108        info->inbound.bytes_avail_towrite =
 109                debug_info.inbound.bytes_avail_towrite;
 110
 111        info->outbound.int_mask =
 112                debug_info.outbound.current_interrupt_mask;
 113        info->outbound.read_idx = debug_info.outbound.current_read_index;
 114        info->outbound.write_idx = debug_info.outbound.current_write_index;
 115        info->outbound.bytes_avail_toread =
 116                debug_info.outbound.bytes_avail_toread;
 117        info->outbound.bytes_avail_towrite =
 118                debug_info.outbound.bytes_avail_towrite;
 119}
 120
 121#define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 122static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 123{
 124        int i;
 125        for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 126                sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 127}
 128
 129/*
 130 * vmbus_show_device_attr - Show the device attribute in sysfs.
 131 *
 132 * This is invoked when user does a
 133 * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
 134 */
 135static ssize_t vmbus_show_device_attr(struct device *dev,
 136                                      struct device_attribute *dev_attr,
 137                                      char *buf)
 138{
 139        struct hv_device *hv_dev = device_to_hv_device(dev);
 140        struct hv_device_info *device_info;
 141        char alias_name[VMBUS_ALIAS_LEN + 1];
 142        int ret = 0;
 143
 144        device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
 145        if (!device_info)
 146                return ret;
 147
 148        get_channel_info(hv_dev, device_info);
 149
 150        if (!strcmp(dev_attr->attr.name, "class_id")) {
 151                ret = sprintf(buf, "{%pUl}\n", device_info->chn_type.b);
 152        } else if (!strcmp(dev_attr->attr.name, "device_id")) {
 153                ret = sprintf(buf, "{%pUl}\n", device_info->chn_instance.b);
 154        } else if (!strcmp(dev_attr->attr.name, "modalias")) {
 155                print_alias_name(hv_dev, alias_name);
 156                ret = sprintf(buf, "vmbus:%s\n", alias_name);
 157        } else if (!strcmp(dev_attr->attr.name, "state")) {
 158                ret = sprintf(buf, "%d\n", device_info->chn_state);
 159        } else if (!strcmp(dev_attr->attr.name, "id")) {
 160                ret = sprintf(buf, "%d\n", device_info->chn_id);
 161        } else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
 162                ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
 163        } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
 164                ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
 165        } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
 166                ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
 167        } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
 168                ret = sprintf(buf, "%d\n",
 169                               device_info->outbound.bytes_avail_toread);
 170        } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
 171                ret = sprintf(buf, "%d\n",
 172                               device_info->outbound.bytes_avail_towrite);
 173        } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
 174                ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
 175        } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
 176                ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
 177        } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
 178                ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
 179        } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
 180                ret = sprintf(buf, "%d\n",
 181                               device_info->inbound.bytes_avail_toread);
 182        } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
 183                ret = sprintf(buf, "%d\n",
 184                               device_info->inbound.bytes_avail_towrite);
 185        } else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
 186                ret = sprintf(buf, "%d\n", device_info->monitor_id);
 187        } else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
 188                ret = sprintf(buf, "%d\n", device_info->server_monitor_pending);
 189        } else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
 190                ret = sprintf(buf, "%d\n", device_info->server_monitor_latency);
 191        } else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
 192                ret = sprintf(buf, "%d\n",
 193                               device_info->server_monitor_conn_id);
 194        } else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
 195                ret = sprintf(buf, "%d\n", device_info->client_monitor_pending);
 196        } else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
 197                ret = sprintf(buf, "%d\n", device_info->client_monitor_latency);
 198        } else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
 199                ret = sprintf(buf, "%d\n",
 200                               device_info->client_monitor_conn_id);
 201        }
 202
 203        kfree(device_info);
 204        return ret;
 205}
 206
 207/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 208static struct device_attribute vmbus_device_attrs[] = {
 209        __ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
 210        __ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
 211        __ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
 212        __ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
 213        __ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
 214        __ATTR(modalias, S_IRUGO, vmbus_show_device_attr, NULL),
 215
 216        __ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 217        __ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 218        __ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 219
 220        __ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 221        __ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 222        __ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 223
 224        __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 225        __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 226        __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 227        __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 228        __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 229
 230        __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 231        __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 232        __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 233        __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 234        __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 235        __ATTR_NULL
 236};
 237
 238
 239/*
 240 * vmbus_uevent - add uevent for our device
 241 *
 242 * This routine is invoked when a device is added or removed on the vmbus to
 243 * generate a uevent to udev in the userspace. The udev will then look at its
 244 * rule and the uevent generated here to load the appropriate driver
 245 *
 246 * The alias string will be of the form vmbus:guid where guid is the string
 247 * representation of the device guid (each byte of the guid will be
 248 * represented with two hex characters.
 249 */
 250static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 251{
 252        struct hv_device *dev = device_to_hv_device(device);
 253        int ret;
 254        char alias_name[VMBUS_ALIAS_LEN + 1];
 255
 256        print_alias_name(dev, alias_name);
 257        ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 258        return ret;
 259}
 260
 261static uuid_le null_guid;
 262
 263static inline bool is_null_guid(const __u8 *guid)
 264{
 265        if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 266                return false;
 267        return true;
 268}
 269
 270/*
 271 * Return a matching hv_vmbus_device_id pointer.
 272 * If there is no match, return NULL.
 273 */
 274static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 275                                        const struct hv_vmbus_device_id *id,
 276                                        __u8 *guid)
 277{
 278        for (; !is_null_guid(id->guid); id++)
 279                if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
 280                        return id;
 281
 282        return NULL;
 283}
 284
 285
 286
 287/*
 288 * vmbus_match - Attempt to match the specified device to the specified driver
 289 */
 290static int vmbus_match(struct device *device, struct device_driver *driver)
 291{
 292        struct hv_driver *drv = drv_to_hv_drv(driver);
 293        struct hv_device *hv_dev = device_to_hv_device(device);
 294
 295        if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
 296                return 1;
 297
 298        return 0;
 299}
 300
 301/*
 302 * vmbus_probe - Add the new vmbus's child device
 303 */
 304static int vmbus_probe(struct device *child_device)
 305{
 306        int ret = 0;
 307        struct hv_driver *drv =
 308                        drv_to_hv_drv(child_device->driver);
 309        struct hv_device *dev = device_to_hv_device(child_device);
 310        const struct hv_vmbus_device_id *dev_id;
 311
 312        dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
 313        if (drv->probe) {
 314                ret = drv->probe(dev, dev_id);
 315                if (ret != 0)
 316                        pr_err("probe failed for device %s (%d)\n",
 317                               dev_name(child_device), ret);
 318
 319        } else {
 320                pr_err("probe not set for driver %s\n",
 321                       dev_name(child_device));
 322                ret = -ENODEV;
 323        }
 324        return ret;
 325}
 326
 327/*
 328 * vmbus_remove - Remove a vmbus device
 329 */
 330static int vmbus_remove(struct device *child_device)
 331{
 332        struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
 333        struct hv_device *dev = device_to_hv_device(child_device);
 334
 335        if (drv->remove)
 336                drv->remove(dev);
 337        else
 338                pr_err("remove not set for driver %s\n",
 339                        dev_name(child_device));
 340
 341        return 0;
 342}
 343
 344
 345/*
 346 * vmbus_shutdown - Shutdown a vmbus device
 347 */
 348static void vmbus_shutdown(struct device *child_device)
 349{
 350        struct hv_driver *drv;
 351        struct hv_device *dev = device_to_hv_device(child_device);
 352
 353
 354        /* The device may not be attached yet */
 355        if (!child_device->driver)
 356                return;
 357
 358        drv = drv_to_hv_drv(child_device->driver);
 359
 360        if (drv->shutdown)
 361                drv->shutdown(dev);
 362
 363        return;
 364}
 365
 366
 367/*
 368 * vmbus_device_release - Final callback release of the vmbus child device
 369 */
 370static void vmbus_device_release(struct device *device)
 371{
 372        struct hv_device *hv_dev = device_to_hv_device(device);
 373
 374        kfree(hv_dev);
 375
 376}
 377
 378/* The one and only one */
 379static struct bus_type  hv_bus = {
 380        .name =         "vmbus",
 381        .match =                vmbus_match,
 382        .shutdown =             vmbus_shutdown,
 383        .remove =               vmbus_remove,
 384        .probe =                vmbus_probe,
 385        .uevent =               vmbus_uevent,
 386        .dev_attrs =    vmbus_device_attrs,
 387};
 388
 389static const char *driver_name = "hyperv";
 390
 391
 392struct onmessage_work_context {
 393        struct work_struct work;
 394        struct hv_message msg;
 395};
 396
 397static void vmbus_onmessage_work(struct work_struct *work)
 398{
 399        struct onmessage_work_context *ctx;
 400
 401        ctx = container_of(work, struct onmessage_work_context,
 402                           work);
 403        vmbus_onmessage(&ctx->msg);
 404        kfree(ctx);
 405}
 406
 407static void vmbus_on_msg_dpc(unsigned long data)
 408{
 409        int cpu = smp_processor_id();
 410        void *page_addr = hv_context.synic_message_page[cpu];
 411        struct hv_message *msg = (struct hv_message *)page_addr +
 412                                  VMBUS_MESSAGE_SINT;
 413        struct onmessage_work_context *ctx;
 414
 415        while (1) {
 416                if (msg->header.message_type == HVMSG_NONE) {
 417                        /* no msg */
 418                        break;
 419                } else {
 420                        ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 421                        if (ctx == NULL)
 422                                continue;
 423                        INIT_WORK(&ctx->work, vmbus_onmessage_work);
 424                        memcpy(&ctx->msg, msg, sizeof(*msg));
 425                        queue_work(vmbus_connection.work_queue, &ctx->work);
 426                }
 427
 428                msg->header.message_type = HVMSG_NONE;
 429
 430                /*
 431                 * Make sure the write to MessageType (ie set to
 432                 * HVMSG_NONE) happens before we read the
 433                 * MessagePending and EOMing. Otherwise, the EOMing
 434                 * will not deliver any more messages since there is
 435                 * no empty slot
 436                 */
 437                mb();
 438
 439                if (msg->header.message_flags.msg_pending) {
 440                        /*
 441                         * This will cause message queue rescan to
 442                         * possibly deliver another msg from the
 443                         * hypervisor
 444                         */
 445                        wrmsrl(HV_X64_MSR_EOM, 0);
 446                }
 447        }
 448}
 449
 450static irqreturn_t vmbus_isr(int irq, void *dev_id)
 451{
 452        int cpu = smp_processor_id();
 453        void *page_addr;
 454        struct hv_message *msg;
 455        union hv_synic_event_flags *event;
 456        bool handled = false;
 457
 458        page_addr = hv_context.synic_event_page[cpu];
 459        if (page_addr == NULL)
 460                return IRQ_NONE;
 461
 462        event = (union hv_synic_event_flags *)page_addr +
 463                                         VMBUS_MESSAGE_SINT;
 464        /*
 465         * Check for events before checking for messages. This is the order
 466         * in which events and messages are checked in Windows guests on
 467         * Hyper-V, and the Windows team suggested we do the same.
 468         */
 469
 470        if ((vmbus_proto_version == VERSION_WS2008) ||
 471                (vmbus_proto_version == VERSION_WIN7)) {
 472
 473                /* Since we are a child, we only need to check bit 0 */
 474                if (sync_test_and_clear_bit(0,
 475                        (unsigned long *) &event->flags32[0])) {
 476                        handled = true;
 477                }
 478        } else {
 479                /*
 480                 * Our host is win8 or above. The signaling mechanism
 481                 * has changed and we can directly look at the event page.
 482                 * If bit n is set then we have an interrup on the channel
 483                 * whose id is n.
 484                 */
 485                handled = true;
 486        }
 487
 488        if (handled)
 489                tasklet_schedule(hv_context.event_dpc[cpu]);
 490
 491
 492        page_addr = hv_context.synic_message_page[cpu];
 493        msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 494
 495        /* Check if there are actual msgs to be processed */
 496        if (msg->header.message_type != HVMSG_NONE) {
 497                handled = true;
 498                tasklet_schedule(&msg_dpc);
 499        }
 500
 501        if (handled)
 502                return IRQ_HANDLED;
 503        else
 504                return IRQ_NONE;
 505}
 506
 507/*
 508 * vmbus interrupt flow handler:
 509 * vmbus interrupts can concurrently occur on multiple CPUs and
 510 * can be handled concurrently.
 511 */
 512
 513static void vmbus_flow_handler(unsigned int irq, struct irq_desc *desc)
 514{
 515        kstat_incr_irqs_this_cpu(irq, desc);
 516
 517        desc->action->handler(irq, desc->action->dev_id);
 518}
 519
 520/*
 521 * vmbus_bus_init -Main vmbus driver initialization routine.
 522 *
 523 * Here, we
 524 *      - initialize the vmbus driver context
 525 *      - invoke the vmbus hv main init routine
 526 *      - get the irq resource
 527 *      - retrieve the channel offers
 528 */
 529static int vmbus_bus_init(int irq)
 530{
 531        int ret;
 532
 533        /* Hypervisor initialization...setup hypercall page..etc */
 534        ret = hv_init();
 535        if (ret != 0) {
 536                pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 537                return ret;
 538        }
 539
 540        tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 541
 542        ret = bus_register(&hv_bus);
 543        if (ret)
 544                goto err_cleanup;
 545
 546        ret = request_irq(irq, vmbus_isr, 0, driver_name, hv_acpi_dev);
 547
 548        if (ret != 0) {
 549                pr_err("Unable to request IRQ %d\n",
 550                           irq);
 551                goto err_unregister;
 552        }
 553
 554        /*
 555         * Vmbus interrupts can be handled concurrently on
 556         * different CPUs. Establish an appropriate interrupt flow
 557         * handler that can support this model.
 558         */
 559        irq_set_handler(irq, vmbus_flow_handler);
 560
 561        /*
 562         * Register our interrupt handler.
 563         */
 564        hv_register_vmbus_handler(irq, vmbus_isr);
 565
 566        ret = hv_synic_alloc();
 567        if (ret)
 568                goto err_alloc;
 569        /*
 570         * Initialize the per-cpu interrupt state and
 571         * connect to the host.
 572         */
 573        on_each_cpu(hv_synic_init, NULL, 1);
 574        ret = vmbus_connect();
 575        if (ret)
 576                goto err_alloc;
 577
 578        vmbus_request_offers();
 579
 580        return 0;
 581
 582err_alloc:
 583        hv_synic_free();
 584        free_irq(irq, hv_acpi_dev);
 585
 586err_unregister:
 587        bus_unregister(&hv_bus);
 588
 589err_cleanup:
 590        hv_cleanup();
 591
 592        return ret;
 593}
 594
 595/**
 596 * __vmbus_child_driver_register - Register a vmbus's driver
 597 * @drv: Pointer to driver structure you want to register
 598 * @owner: owner module of the drv
 599 * @mod_name: module name string
 600 *
 601 * Registers the given driver with Linux through the 'driver_register()' call
 602 * and sets up the hyper-v vmbus handling for this driver.
 603 * It will return the state of the 'driver_register()' call.
 604 *
 605 */
 606int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 607{
 608        int ret;
 609
 610        pr_info("registering driver %s\n", hv_driver->name);
 611
 612        ret = vmbus_exists();
 613        if (ret < 0)
 614                return ret;
 615
 616        hv_driver->driver.name = hv_driver->name;
 617        hv_driver->driver.owner = owner;
 618        hv_driver->driver.mod_name = mod_name;
 619        hv_driver->driver.bus = &hv_bus;
 620
 621        ret = driver_register(&hv_driver->driver);
 622
 623        return ret;
 624}
 625EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 626
 627/**
 628 * vmbus_driver_unregister() - Unregister a vmbus's driver
 629 * @drv: Pointer to driver structure you want to un-register
 630 *
 631 * Un-register the given driver that was previous registered with a call to
 632 * vmbus_driver_register()
 633 */
 634void vmbus_driver_unregister(struct hv_driver *hv_driver)
 635{
 636        pr_info("unregistering driver %s\n", hv_driver->name);
 637
 638        if (!vmbus_exists())
 639                driver_unregister(&hv_driver->driver);
 640}
 641EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 642
 643/*
 644 * vmbus_device_create - Creates and registers a new child device
 645 * on the vmbus.
 646 */
 647struct hv_device *vmbus_device_create(uuid_le *type,
 648                                            uuid_le *instance,
 649                                            struct vmbus_channel *channel)
 650{
 651        struct hv_device *child_device_obj;
 652
 653        child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 654        if (!child_device_obj) {
 655                pr_err("Unable to allocate device object for child device\n");
 656                return NULL;
 657        }
 658
 659        child_device_obj->channel = channel;
 660        memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 661        memcpy(&child_device_obj->dev_instance, instance,
 662               sizeof(uuid_le));
 663
 664
 665        return child_device_obj;
 666}
 667
 668/*
 669 * vmbus_device_register - Register the child device
 670 */
 671int vmbus_device_register(struct hv_device *child_device_obj)
 672{
 673        int ret = 0;
 674
 675        static atomic_t device_num = ATOMIC_INIT(0);
 676
 677        dev_set_name(&child_device_obj->device, "vmbus_0_%d",
 678                     atomic_inc_return(&device_num));
 679
 680        child_device_obj->device.bus = &hv_bus;
 681        child_device_obj->device.parent = &hv_acpi_dev->dev;
 682        child_device_obj->device.release = vmbus_device_release;
 683
 684        /*
 685         * Register with the LDM. This will kick off the driver/device
 686         * binding...which will eventually call vmbus_match() and vmbus_probe()
 687         */
 688        ret = device_register(&child_device_obj->device);
 689
 690        if (ret)
 691                pr_err("Unable to register child device\n");
 692        else
 693                pr_debug("child device %s registered\n",
 694                        dev_name(&child_device_obj->device));
 695
 696        return ret;
 697}
 698
 699/*
 700 * vmbus_device_unregister - Remove the specified child device
 701 * from the vmbus.
 702 */
 703void vmbus_device_unregister(struct hv_device *device_obj)
 704{
 705        pr_debug("child device %s unregistered\n",
 706                dev_name(&device_obj->device));
 707
 708        /*
 709         * Kick off the process of unregistering the device.
 710         * This will call vmbus_remove() and eventually vmbus_device_release()
 711         */
 712        device_unregister(&device_obj->device);
 713}
 714
 715
 716/*
 717 * VMBUS is an acpi enumerated device. Get the the IRQ information
 718 * from DSDT.
 719 */
 720
 721static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
 722{
 723
 724        if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
 725                struct acpi_resource_irq *irqp;
 726                irqp = &res->data.irq;
 727
 728                *((unsigned int *)irq) = irqp->interrupts[0];
 729        }
 730
 731        return AE_OK;
 732}
 733
 734static int vmbus_acpi_add(struct acpi_device *device)
 735{
 736        acpi_status result;
 737
 738        hv_acpi_dev = device;
 739
 740        result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 741                                        vmbus_walk_resources, &irq);
 742
 743        if (ACPI_FAILURE(result)) {
 744                complete(&probe_event);
 745                return -ENODEV;
 746        }
 747        complete(&probe_event);
 748        return 0;
 749}
 750
 751static const struct acpi_device_id vmbus_acpi_device_ids[] = {
 752        {"VMBUS", 0},
 753        {"VMBus", 0},
 754        {"", 0},
 755};
 756MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
 757
 758static struct acpi_driver vmbus_acpi_driver = {
 759        .name = "vmbus",
 760        .ids = vmbus_acpi_device_ids,
 761        .ops = {
 762                .add = vmbus_acpi_add,
 763        },
 764};
 765
 766static int __init hv_acpi_init(void)
 767{
 768        int ret, t;
 769
 770        if (x86_hyper != &x86_hyper_ms_hyperv)
 771                return -ENODEV;
 772
 773        init_completion(&probe_event);
 774
 775        /*
 776         * Get irq resources first.
 777         */
 778
 779        ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 780
 781        if (ret)
 782                return ret;
 783
 784        t = wait_for_completion_timeout(&probe_event, 5*HZ);
 785        if (t == 0) {
 786                ret = -ETIMEDOUT;
 787                goto cleanup;
 788        }
 789
 790        if (irq <= 0) {
 791                ret = -ENODEV;
 792                goto cleanup;
 793        }
 794
 795        ret = vmbus_bus_init(irq);
 796        if (ret)
 797                goto cleanup;
 798
 799        return 0;
 800
 801cleanup:
 802        acpi_bus_unregister_driver(&vmbus_acpi_driver);
 803        hv_acpi_dev = NULL;
 804        return ret;
 805}
 806
 807static void __exit vmbus_exit(void)
 808{
 809
 810        free_irq(irq, hv_acpi_dev);
 811        vmbus_free_channels();
 812        bus_unregister(&hv_bus);
 813        hv_cleanup();
 814        acpi_bus_unregister_driver(&vmbus_acpi_driver);
 815}
 816
 817
 818MODULE_LICENSE("GPL");
 819
 820subsys_initcall(hv_acpi_init);
 821module_exit(vmbus_exit);
 822
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