drivers/staging/hv/storvsc_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 #include <linux/kernel.h>
  24 #include <linux/wait.h>
  25 #include <linux/sched.h>
  26 #include <linux/completion.h>
  27 #include <linux/string.h>
  28 #include <linux/mm.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/device.h>
  34 #include <scsi/scsi.h>
  35 #include <scsi/scsi_cmnd.h>
  36 #include <scsi/scsi_host.h>
  37 #include <scsi/scsi_device.h>
  38 #include <scsi/scsi_tcq.h>
  39 #include <scsi/scsi_eh.h>
  40 #include <scsi/scsi_devinfo.h>
  41 #include <scsi/scsi_dbg.h>
  42
  43 #include "hyperv.h"
  44
  45 #define STORVSC_RING_BUFFER_SIZE                        (20*PAGE_SIZE)
  46 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
  47
  48 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
  49 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
  50
  51 /* to alert the user that structure sizes may be mismatched even though the */
  52 /* protocol versions match. */
  53
  54
  55 #define REVISION_STRING(REVISION_) #REVISION_
  56 #define FILL_VMSTOR_REVISION(RESULT_LVALUE_)                            \
  57         do {                                                            \
  58                 char *revision_string                                   \
  59                         = REVISION_STRING($Rev : 6 $) + 6;              \
  60                 RESULT_LVALUE_ = 0;                                     \
  61                 while (*revision_string >= '0'                          \
  62                         && *revision_string <= '9') {                   \
  63                         RESULT_LVALUE_ *= 10;                           \
  64                         RESULT_LVALUE_ += *revision_string - '0';       \
  65                         revision_string++;                              \
  66                 }                                                       \
  67         } while (0)
  68
  69 /* Major/minor macros.  Minor version is in LSB, meaning that earlier flat */
  70 /* version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1). */
  71 #define VMSTOR_PROTOCOL_MAJOR(VERSION_)         (((VERSION_) >> 8) & 0xff)
  72 #define VMSTOR_PROTOCOL_MINOR(VERSION_)         (((VERSION_))      & 0xff)
  73 #define VMSTOR_PROTOCOL_VERSION(MAJOR_, MINOR_) ((((MAJOR_) & 0xff) << 8) | \
  74                                                  (((MINOR_) & 0xff)))
  75 #define VMSTOR_INVALID_PROTOCOL_VERSION         (-1)
  76
  77 /* Version history: */
  78 /* V1 Beta                    0.1 */
  79 /* V1 RC < 2008/1/31          1.0 */
  80 /* V1 RC > 2008/1/31          2.0 */
  81 #define VMSTOR_PROTOCOL_VERSION_CURRENT VMSTOR_PROTOCOL_VERSION(2, 0)
  82
  83
  84
  85
  86 /*  This will get replaced with the max transfer length that is possible on */
  87 /*  the host adapter. */
  88 /*  The max transfer length will be published when we offer a vmbus channel. */
  89 #define MAX_TRANSFER_LENGTH     0x40000
  90 #define DEFAULT_PACKET_SIZE (sizeof(struct vmdata_gpa_direct) + \
  91                         sizeof(struct vstor_packet) +           \
  92                         sizesizeof(u64) * (MAX_TRANSFER_LENGTH / PAGE_SIZE)))
  93
  94
  95 /*  Packet structure describing virtual storage requests. */
  96 enum vstor_packet_operation {
  97         VSTOR_OPERATION_COMPLETE_IO             = 1,
  98         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  99         VSTOR_OPERATION_EXECUTE_SRB             = 3,
 100         VSTOR_OPERATION_RESET_LUN               = 4,
 101         VSTOR_OPERATION_RESET_ADAPTER           = 5,
 102         VSTOR_OPERATION_RESET_BUS               = 6,
 103         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
 104         VSTOR_OPERATION_END_INITIALIZATION      = 8,
 105         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
 106         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
 107         VSTOR_OPERATION_MAXIMUM                 = 10
 108 };
 109
 110 /*
 111  * Platform neutral description of a scsi request -
 112  * this remains the same across the write regardless of 32/64 bit
 113  * note: it's patterned off the SCSI_PASS_THROUGH structure
 114  */
 115 #define CDB16GENERIC_LENGTH                     0x10
 116
 117 #ifndef SENSE_BUFFER_SIZE
 118 #define SENSE_BUFFER_SIZE                       0x12
 119 #endif
 120
 121 #define MAX_DATA_BUF_LEN_WITH_PADDING           0x14
 122
 123 struct vmscsi_request {
 124         unsigned short length;
 125         unsigned char srb_status;
 126         unsigned char scsi_status;
 127
 128         unsigned char port_number;
 129         unsigned char path_id;
 130         unsigned char target_id;
 131         unsigned char lun;
 132
 133         unsigned char cdb_length;
 134         unsigned char sense_info_length;
 135         unsigned char data_in;
 136         unsigned char reserved;
 137
 138         unsigned int data_transfer_length;
 139
 140         union {
 141                 unsigned char cdb[CDB16GENERIC_LENGTH];
 142                 unsigned char sense_data[SENSE_BUFFER_SIZE];
 143                 unsigned char reserved_array[MAX_DATA_BUF_LEN_WITH_PADDING];
 144         };
 145 } __attribute((packed));
 146
 147
 148 /*
 149  * This structure is sent during the intialization phase to get the different
 150  * properties of the channel.
 151  */
 152 struct vmstorage_channel_properties {
 153         unsigned short protocol_version;
 154         unsigned char path_id;
 155         unsigned char target_id;
 156
 157         /* Note: port number is only really known on the client side */
 158         unsigned int port_number;
 159         unsigned int flags;
 160         unsigned int max_transfer_bytes;
 161
 162         /*  This id is unique for each channel and will correspond with */
 163         /*  vendor specific data in the inquirydata */
 164         unsigned long long unique_id;
 165 } __packed;
 166
 167 /*  This structure is sent during the storage protocol negotiations. */
 168 struct vmstorage_protocol_version {
 169         /* Major (MSW) and minor (LSW) version numbers. */
 170         unsigned short major_minor;
 171
 172         /*
 173          * Revision number is auto-incremented whenever this file is changed
 174          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 175          * definitely indicate incompatibility--but it does indicate mismatched
 176          * builds.
 177          */
 178         unsigned short revision;
 179 } __packed;
 180
 181 /* Channel Property Flags */
 182 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 183 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 184
 185 struct vstor_packet {
 186         /* Requested operation type */
 187         enum vstor_packet_operation operation;
 188
 189         /*  Flags - see below for values */
 190         unsigned int flags;
 191
 192         /* Status of the request returned from the server side. */
 193         unsigned int status;
 194
 195         /* Data payload area */
 196         union {
 197                 /*
 198                  * Structure used to forward SCSI commands from the
 199                  * client to the server.
 200                  */
 201                 struct vmscsi_request vm_srb;
 202
 203                 /* Structure used to query channel properties. */
 204                 struct vmstorage_channel_properties storage_channel_properties;
 205
 206                 /* Used during version negotiations. */
 207                 struct vmstorage_protocol_version version;
 208         };
 209 } __packed;
 210
 211 /* Packet flags */
 212 /*
 213  * This flag indicates that the server should send back a completion for this
 214  * packet.
 215  */
 216 #define REQUEST_COMPLETION_FLAG 0x1
 217
 218 /*  This is the set of flags that the vsc can set in any packets it sends */
 219 #define VSC_LEGAL_FLAGS         (REQUEST_COMPLETION_FLAG)
 220
 221
 222 /* Defines */
 223
 224 #define STORVSC_MAX_IO_REQUESTS                         128
 225
 226 /*
 227  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
 228  * reality, the path/target is not used (ie always set to 0) so our
 229  * scsi host adapter essentially has 1 bus with 1 target that contains
 230  * up to 256 luns.
 231  */
 232 #define STORVSC_MAX_LUNS_PER_TARGET                     64
 233 #define STORVSC_MAX_TARGETS                             1
 234 #define STORVSC_MAX_CHANNELS                            1
 235 #define STORVSC_MAX_CMD_LEN                             16
 236
 237 struct hv_storvsc_request;
 238
 239 /* Matches Windows-end */
 240 enum storvsc_request_type {
 241         WRITE_TYPE,
 242         READ_TYPE,
 243         UNKNOWN_TYPE,
 244 };
 245
 246
 247 struct hv_storvsc_request {
 248         struct hv_storvsc_request *request;
 249         struct hv_device *device;
 250
 251         /* Synchronize the request/response if needed */
 252         struct completion wait_event;
 253
 254         unsigned char *sense_buffer;
 255         void *context;
 256         void (*on_io_completion)(struct hv_storvsc_request *request);
 257         struct hv_multipage_buffer data_buffer;
 258
 259         struct vstor_packet vstor_packet;
 260 };
 261
 262
 263 struct storvsc_device_info {
 264         u32 ring_buffer_size;
 265         unsigned int port_number;
 266         unsigned char path_id;
 267         unsigned char target_id;
 268 };
 269
 270
 271 /* A storvsc device is a device object that contains a vmbus channel */
 272 struct storvsc_device {
 273         struct hv_device *device;
 274
 275         bool     destroy;
 276         bool     drain_notify;
 277         atomic_t num_outstanding_req;
 278
 279         wait_queue_head_t waiting_to_drain;
 280
 281         /*
 282          * Each unique Port/Path/Target represents 1 channel ie scsi
 283          * controller. In reality, the pathid, targetid is always 0
 284          * and the port is set by us
 285          */
 286         unsigned int port_number;
 287         unsigned char path_id;
 288         unsigned char target_id;
 289
 290         /* Used for vsc/vsp channel reset process */
 291         struct hv_storvsc_request init_request;
 292         struct hv_storvsc_request reset_request;
 293 };
 294
 295 struct hv_host_device {
 296         struct hv_device *dev;
 297         struct kmem_cache *request_pool;
 298         unsigned int port;
 299         unsigned char path;
 300         unsigned char target;
 301 };
 302
 303 struct storvsc_cmd_request {
 304         struct list_head entry;
 305         struct scsi_cmnd *cmd;
 306
 307         unsigned int bounce_sgl_count;
 308         struct scatterlist *bounce_sgl;
 309
 310         struct hv_storvsc_request request;
 311 };
 312
 313 static inline struct storvsc_device *get_out_stor_device(
 314                                         struct hv_device *device)
 315 {
 316         struct storvsc_device *stor_device;
 317
 318         stor_device = (struct storvsc_device *)device->ext;
 319
 320         if (stor_device && stor_device->destroy)
 321                 stor_device = NULL;
 322
 323         return stor_device;
 324 }
 325
 326
 327 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 328 {
 329         dev->drain_notify = true;
 330         wait_event(dev->waiting_to_drain,
 331                    atomic_read(&dev->num_outstanding_req) == 0);
 332         dev->drain_notify = false;
 333 }
 334
 335 static inline struct storvsc_device *get_in_stor_device(
 336                                         struct hv_device *device)
 337 {
 338         struct storvsc_device *stor_device;
 339
 340         stor_device = (struct storvsc_device *)device->ext;
 341
 342         if (!stor_device)
 343                 goto get_in_err;
 344
 345         /*
 346          * If the device is being destroyed; allow incoming
 347          * traffic only to cleanup outstanding requests.
 348          */
 349
 350         if (stor_device->destroy  &&
 351                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 352                 stor_device = NULL;
 353
 354 get_in_err:
 355         return stor_device;
 356
 357 }
 358
 359 static int storvsc_channel_init(struct hv_device *device)
 360 {
 361         struct storvsc_device *stor_device;
 362         struct hv_storvsc_request *request;
 363         struct vstor_packet *vstor_packet;
 364         int ret, t;
 365
 366         stor_device = get_out_stor_device(device);
 367         if (!stor_device)
 368                 return -ENODEV;
 369
 370         request = &stor_device->init_request;
 371         vstor_packet = &request->vstor_packet;
 372
 373         /*
 374          * Now, initiate the vsc/vsp initialization protocol on the open
 375          * channel
 376          */
 377         memset(request, 0, sizeof(struct hv_storvsc_request));
 378         init_completion(&request->wait_event);
 379         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 380         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 381
 382         ret = vmbus_sendpacket(device->channel, vstor_packet,
 383                                sizeof(struct vstor_packet),
 384                                (unsigned long)request,
 385                                VM_PKT_DATA_INBAND,
 386                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 387         if (ret != 0)
 388                 goto cleanup;
 389
 390         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 391         if (t == 0) {
 392                 ret = -ETIMEDOUT;
 393                 goto cleanup;
 394         }
 395
 396         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 397             vstor_packet->status != 0)
 398                 goto cleanup;
 399
 400
 401         /* reuse the packet for version range supported */
 402         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 403         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 404         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 405
 406         vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
 407         FILL_VMSTOR_REVISION(vstor_packet->version.revision);
 408
 409         ret = vmbus_sendpacket(device->channel, vstor_packet,
 410                                sizeof(struct vstor_packet),
 411                                (unsigned long)request,
 412                                VM_PKT_DATA_INBAND,
 413                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 414         if (ret != 0)
 415                 goto cleanup;
 416
 417         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 418         if (t == 0) {
 419                 ret = -ETIMEDOUT;
 420                 goto cleanup;
 421         }
 422
 423         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 424             vstor_packet->status != 0)
 425                 goto cleanup;
 426
 427
 428         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 429         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 430         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 431         vstor_packet->storage_channel_properties.port_number =
 432                                         stor_device->port_number;
 433
 434         ret = vmbus_sendpacket(device->channel, vstor_packet,
 435                                sizeof(struct vstor_packet),
 436                                (unsigned long)request,
 437                                VM_PKT_DATA_INBAND,
 438                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 439
 440         if (ret != 0)
 441                 goto cleanup;
 442
 443         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 444         if (t == 0) {
 445                 ret = -ETIMEDOUT;
 446                 goto cleanup;
 447         }
 448
 449         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 450             vstor_packet->status != 0)
 451                 goto cleanup;
 452
 453         stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
 454         stor_device->target_id
 455                 = vstor_packet->storage_channel_properties.target_id;
 456
 457         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 458         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 459         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 460
 461         ret = vmbus_sendpacket(device->channel, vstor_packet,
 462                                sizeof(struct vstor_packet),
 463                                (unsigned long)request,
 464                                VM_PKT_DATA_INBAND,
 465                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 466
 467         if (ret != 0)
 468                 goto cleanup;
 469
 470         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 471         if (t == 0) {
 472                 ret = -ETIMEDOUT;
 473                 goto cleanup;
 474         }
 475
 476         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 477             vstor_packet->status != 0)
 478                 goto cleanup;
 479
 480
 481 cleanup:
 482         return ret;
 483 }
 484
 485 static void storvsc_on_io_completion(struct hv_device *device,
 486                                   struct vstor_packet *vstor_packet,
 487                                   struct hv_storvsc_request *request)
 488 {
 489         struct storvsc_device *stor_device;
 490         struct vstor_packet *stor_pkt;
 491
 492         stor_device = (struct storvsc_device *)device->ext;
 493
 494         stor_pkt = &request->vstor_packet;
 495
 496         /*
 497          * The current SCSI handling on the host side does
 498          * not correctly handle:
 499          * INQUIRY command with page code parameter set to 0x80
 500          * MODE_SENSE command with cmd[2] == 0x1c
 501          *
 502          * Setup srb and scsi status so this won't be fatal.
 503          * We do this so we can distinguish truly fatal failues
 504          * (srb status == 0x4) and off-line the device in that case.
 505          */
 506
 507         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
 508                 (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
 509                 vstor_packet->vm_srb.scsi_status = 0;
 510                 vstor_packet->vm_srb.srb_status = 0x1;
 511         }
 512
 513
 514         /* Copy over the status...etc */
 515         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 516         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 517         stor_pkt->vm_srb.sense_info_length =
 518         vstor_packet->vm_srb.sense_info_length;
 519
 520         if (vstor_packet->vm_srb.scsi_status != 0 ||
 521                 vstor_packet->vm_srb.srb_status != 1){
 522                 DPRINT_WARN(STORVSC,
 523                             "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 524                             stor_pkt->vm_srb.cdb[0],
 525                             vstor_packet->vm_srb.scsi_status,
 526                             vstor_packet->vm_srb.srb_status);
 527         }
 528
 529         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 530                 /* CHECK_CONDITION */
 531                 if (vstor_packet->vm_srb.srb_status & 0x80) {
 532                         /* autosense data available */
 533                         DPRINT_WARN(STORVSC, "storvsc pkt %p autosense data "
 534                                     "valid - len %d\n", request,
 535                                     vstor_packet->vm_srb.sense_info_length);
 536
 537                         memcpy(request->sense_buffer,
 538                                vstor_packet->vm_srb.sense_data,
 539                                vstor_packet->vm_srb.sense_info_length);
 540
 541                 }
 542         }
 543
 544         stor_pkt->vm_srb.data_transfer_length =
 545         vstor_packet->vm_srb.data_transfer_length;
 546
 547         request->on_io_completion(request);
 548
 549         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 550                 stor_device->drain_notify)
 551                 wake_up(&stor_device->waiting_to_drain);
 552
 553
 554 }
 555
 556 static void storvsc_on_receive(struct hv_device *device,
 557                              struct vstor_packet *vstor_packet,
 558                              struct hv_storvsc_request *request)
 559 {
 560         switch (vstor_packet->operation) {
 561         case VSTOR_OPERATION_COMPLETE_IO:
 562                 storvsc_on_io_completion(device, vstor_packet, request);
 563                 break;
 564         case VSTOR_OPERATION_REMOVE_DEVICE:
 565
 566         default:
 567                 break;
 568         }
 569 }
 570
 571 static void storvsc_on_channel_callback(void *context)
 572 {
 573         struct hv_device *device = (struct hv_device *)context;
 574         struct storvsc_device *stor_device;
 575         u32 bytes_recvd;
 576         u64 request_id;
 577         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 578         struct hv_storvsc_request *request;
 579         int ret;
 580
 581
 582         stor_device = get_in_stor_device(device);
 583         if (!stor_device)
 584                 return;
 585
 586         do {
 587                 ret = vmbus_recvpacket(device->channel, packet,
 588                                        ALIGN(sizeof(struct vstor_packet), 8),
 589                                        &bytes_recvd, &request_id);
 590                 if (ret == 0 && bytes_recvd > 0) {
 591
 592                         request = (struct hv_storvsc_request *)
 593                                         (unsigned long)request_id;
 594
 595                         if ((request == &stor_device->init_request) ||
 596                             (request == &stor_device->reset_request)) {
 597
 598                                 memcpy(&request->vstor_packet, packet,
 599                                        sizeof(struct vstor_packet));
 600                                 complete(&request->wait_event);
 601                         } else {
 602                                 storvsc_on_receive(device,
 603                                                 (struct vstor_packet *)packet,
 604                                                 request);
 605                         }
 606                 } else {
 607                         break;
 608                 }
 609         } while (1);
 610
 611         return;
 612 }
 613
 614 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 615 {
 616         struct vmstorage_channel_properties props;
 617         int ret;
 618
 619         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 620
 621         /* Open the channel */
 622         ret = vmbus_open(device->channel,
 623                          ring_size,
 624                          ring_size,
 625                          (void *)&props,
 626                          sizeof(struct vmstorage_channel_properties),
 627                          storvsc_on_channel_callback, device);
 628
 629         if (ret != 0)
 630                 return ret;
 631
 632         ret = storvsc_channel_init(device);
 633
 634         return ret;
 635 }
 636
 637 static int storvsc_dev_remove(struct hv_device *device)
 638 {
 639         struct storvsc_device *stor_device;
 640         unsigned long flags;
 641
 642         stor_device = (struct storvsc_device *)device->ext;
 643
 644         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 645         stor_device->destroy = true;
 646         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 647
 648         /*
 649          * At this point, all outbound traffic should be disable. We
 650          * only allow inbound traffic (responses) to proceed so that
 651          * outstanding requests can be completed.
 652          */
 653
 654         storvsc_wait_to_drain(stor_device);
 655
 656         /*
 657          * Since we have already drained, we don't need to busy wait
 658          * as was done in final_release_stor_device()
 659          * Note that we cannot set the ext pointer to NULL until
 660          * we have drained - to drain the outgoing packets, we need to
 661          * allow incoming packets.
 662          */
 663         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 664         device->ext = NULL;
 665         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 666
 667         /* Close the channel */
 668         vmbus_close(device->channel);
 669
 670         kfree(stor_device);
 671         return 0;
 672 }
 673
 674 static int storvsc_do_io(struct hv_device *device,
 675                               struct hv_storvsc_request *request)
 676 {
 677         struct storvsc_device *stor_device;
 678         struct vstor_packet *vstor_packet;
 679         int ret = 0;
 680
 681         vstor_packet = &request->vstor_packet;
 682         stor_device = get_out_stor_device(device);
 683
 684         if (!stor_device)
 685                 return -ENODEV;
 686
 687
 688         request->device  = device;
 689
 690
 691         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
 692
 693         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
 694
 695
 696         vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
 697
 698
 699         vstor_packet->vm_srb.data_transfer_length =
 700         request->data_buffer.len;
 701
 702         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 703
 704         if (request->data_buffer.len) {
 705                 ret = vmbus_sendpacket_multipagebuffer(device->channel,
 706                                 &request->data_buffer,
 707                                 vstor_packet,
 708                                 sizeof(struct vstor_packet),
 709                                 (unsigned long)request);
 710         } else {
 711                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 712                                sizeof(struct vstor_packet),
 713                                (unsigned long)request,
 714                                VM_PKT_DATA_INBAND,
 715                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 716         }
 717
 718         if (ret != 0)
 719                 return ret;
 720
 721         atomic_inc(&stor_device->num_outstanding_req);
 722
 723         return ret;
 724 }
 725
 726 static void storvsc_get_ide_info(struct hv_device *dev, int *target, int *path)
 727 {
 728         *target =
 729                 dev->dev_instance.b[5] << 8 | dev->dev_instance.b[4];
 730
 731         *path =
 732                 dev->dev_instance.b[3] << 24 |
 733                 dev->dev_instance.b[2] << 16 |
 734                 dev->dev_instance.b[1] << 8  | dev->dev_instance.b[0];
 735 }
 736
 737
 738 static int storvsc_device_alloc(struct scsi_device *sdevice)
 739 {
 740         /*
 741          * This enables luns to be located sparsely. Otherwise, we may not
 742          * discovered them.
 743          */
 744         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 745         return 0;
 746 }
 747
 748 static int storvsc_merge_bvec(struct request_queue *q,
 749                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 750 {
 751         /* checking done by caller. */
 752         return bvec->bv_len;
 753 }
 754
 755 static int storvsc_device_configure(struct scsi_device *sdevice)
 756 {
 757         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 758                                 STORVSC_MAX_IO_REQUESTS);
 759
 760         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 761
 762         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 763
 764         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 765
 766         return 0;
 767 }
 768
 769 static void destroy_bounce_buffer(struct scatterlist *sgl,
 770                                   unsigned int sg_count)
 771 {
 772         int i;
 773         struct page *page_buf;
 774
 775         for (i = 0; i < sg_count; i++) {
 776                 page_buf = sg_page((&sgl[i]));
 777                 if (page_buf != NULL)
 778                         __free_page(page_buf);
 779         }
 780
 781         kfree(sgl);
 782 }
 783
 784 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 785 {
 786         int i;
 787
 788         /* No need to check */
 789         if (sg_count < 2)
 790                 return -1;
 791
 792         /* We have at least 2 sg entries */
 793         for (i = 0; i < sg_count; i++) {
 794                 if (i == 0) {
 795                         /* make sure 1st one does not have hole */
 796                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 797                                 return i;
 798                 } else if (i == sg_count - 1) {
 799                         /* make sure last one does not have hole */
 800                         if (sgl[i].offset != 0)
 801                                 return i;
 802                 } else {
 803                         /* make sure no hole in the middle */
 804                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 805                                 return i;
 806                 }
 807         }
 808         return -1;
 809 }
 810
 811 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 812                                                 unsigned int sg_count,
 813                                                 unsigned int len)
 814 {
 815         int i;
 816         int num_pages;
 817         struct scatterlist *bounce_sgl;
 818         struct page *page_buf;
 819
 820         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 821
 822         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 823         if (!bounce_sgl)
 824                 return NULL;
 825
 826         for (i = 0; i < num_pages; i++) {
 827                 page_buf = alloc_page(GFP_ATOMIC);
 828                 if (!page_buf)
 829                         goto cleanup;
 830                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 831         }
 832
 833         return bounce_sgl;
 834
 835 cleanup:
 836         destroy_bounce_buffer(bounce_sgl, num_pages);
 837         return NULL;
 838 }
 839
 840
 841 /* Assume the original sgl has enough room */
 842 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 843                                             struct scatterlist *bounce_sgl,
 844                                             unsigned int orig_sgl_count)
 845 {
 846         int i;
 847         int j = 0;
 848         unsigned long src, dest;
 849         unsigned int srclen, destlen, copylen;
 850         unsigned int total_copied = 0;
 851         unsigned long bounce_addr = 0;
 852         unsigned long dest_addr = 0;
 853         unsigned long flags;
 854
 855         local_irq_save(flags);
 856
 857         for (i = 0; i < orig_sgl_count; i++) {
 858                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 859                                         KM_IRQ0) + orig_sgl[i].offset;
 860                 dest = dest_addr;
 861                 destlen = orig_sgl[i].length;
 862
 863                 if (bounce_addr == 0)
 864                         bounce_addr =
 865                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 866                                                         KM_IRQ0);
 867
 868                 while (destlen) {
 869                         src = bounce_addr + bounce_sgl[j].offset;
 870                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 871
 872                         copylen = min(srclen, destlen);
 873                         memcpy((void *)dest, (void *)src, copylen);
 874
 875                         total_copied += copylen;
 876                         bounce_sgl[j].offset += copylen;
 877                         destlen -= copylen;
 878                         dest += copylen;
 879
 880                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 881                                 /* full */
 882                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 883                                 j++;
 884
 885                                 /* if we need to use another bounce buffer */
 886                                 if (destlen || i != orig_sgl_count - 1)
 887                                         bounce_addr =
 888                                         (unsigned long)kmap_atomic(
 889                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 890                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 891                                 /* unmap the last bounce that is < PAGE_SIZE */
 892                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 893                         }
 894                 }
 895
 896                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 897                               KM_IRQ0);
 898         }
 899
 900         local_irq_restore(flags);
 901
 902         return total_copied;
 903 }
 904
 905
 906 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 907 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 908                                           struct scatterlist *bounce_sgl,
 909                                           unsigned int orig_sgl_count)
 910 {
 911         int i;
 912         int j = 0;
 913         unsigned long src, dest;
 914         unsigned int srclen, destlen, copylen;
 915         unsigned int total_copied = 0;
 916         unsigned long bounce_addr = 0;
 917         unsigned long src_addr = 0;
 918         unsigned long flags;
 919
 920         local_irq_save(flags);
 921
 922         for (i = 0; i < orig_sgl_count; i++) {
 923                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 924                                 KM_IRQ0) + orig_sgl[i].offset;
 925                 src = src_addr;
 926                 srclen = orig_sgl[i].length;
 927
 928                 if (bounce_addr == 0)
 929                         bounce_addr =
 930                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 931                                                 KM_IRQ0);
 932
 933                 while (srclen) {
 934                         /* assume bounce offset always == 0 */
 935                         dest = bounce_addr + bounce_sgl[j].length;
 936                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 937
 938                         copylen = min(srclen, destlen);
 939                         memcpy((void *)dest, (void *)src, copylen);
 940
 941                         total_copied += copylen;
 942                         bounce_sgl[j].length += copylen;
 943                         srclen -= copylen;
 944                         src += copylen;
 945
 946                         if (bounce_sgl[j].length == PAGE_SIZE) {
 947                                 /* full..move to next entry */
 948                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 949                                 j++;
 950
 951                                 /* if we need to use another bounce buffer */
 952                                 if (srclen || i != orig_sgl_count - 1)
 953                                         bounce_addr =
 954                                         (unsigned long)kmap_atomic(
 955                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 956
 957                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 958                                 /* unmap the last bounce that is < PAGE_SIZE */
 959                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 960                         }
 961                 }
 962
 963                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 964         }
 965
 966         local_irq_restore(flags);
 967
 968         return total_copied;
 969 }
 970
 971
 972 static int storvsc_remove(struct hv_device *dev)
 973 {
 974         struct Scsi_Host *host = dev_get_drvdata(&dev->device);
 975         struct hv_host_device *host_dev =
 976                         (struct hv_host_device *)host->hostdata;
 977
 978         scsi_remove_host(host);
 979
 980         scsi_host_put(host);
 981
 982         storvsc_dev_remove(dev);
 983         if (host_dev->request_pool) {
 984                 kmem_cache_destroy(host_dev->request_pool);
 985                 host_dev->request_pool = NULL;
 986         }
 987         return 0;
 988 }
 989
 990
 991 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 992                            sector_t capacity, int *info)
 993 {
 994         sector_t nsect = capacity;
 995         sector_t cylinders = nsect;
 996         int heads, sectors_pt;
 997
 998         /*
 999          * We are making up these values; let us keep it simple.
1000          */
1001         heads = 0xff;
1002         sectors_pt = 0x3f;      /* Sectors per track */
1003         sector_div(cylinders, heads * sectors_pt);
1004         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1005                 cylinders = 0xffff;
1006
1007         info[0] = heads;
1008         info[1] = sectors_pt;
1009         info[2] = (int)cylinders;
1010
1011         return 0;
1012 }
1013
1014 static int storvsc_host_reset(struct hv_device *device)
1015 {
1016         struct storvsc_device *stor_device;
1017         struct hv_storvsc_request *request;
1018         struct vstor_packet *vstor_packet;
1019         int ret, t;
1020
1021
1022         stor_device = get_out_stor_device(device);
1023         if (!stor_device)
1024                 return -ENODEV;
1025
1026         request = &stor_device->reset_request;
1027         vstor_packet = &request->vstor_packet;
1028
1029         init_completion(&request->wait_event);
1030
1031         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1032         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1033         vstor_packet->vm_srb.path_id = stor_device->path_id;
1034
1035         ret = vmbus_sendpacket(device->channel, vstor_packet,
1036                                sizeof(struct vstor_packet),
1037                                (unsigned long)&stor_device->reset_request,
1038                                VM_PKT_DATA_INBAND,
1039                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1040         if (ret != 0)
1041                 goto cleanup;
1042
1043         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1044         if (t == 0) {
1045                 ret = -ETIMEDOUT;
1046                 goto cleanup;
1047         }
1048
1049
1050         /*
1051          * At this point, all outstanding requests in the adapter
1052          * should have been flushed out and return to us
1053          */
1054
1055 cleanup:
1056         return ret;
1057 }
1058
1059
1060 /*
1061  * storvsc_host_reset_handler - Reset the scsi HBA
1062  */
1063 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1064 {
1065         int ret;
1066         struct hv_host_device *host_dev =
1067                 (struct hv_host_device *)scmnd->device->host->hostdata;
1068         struct hv_device *dev = host_dev->dev;
1069
1070         ret = storvsc_host_reset(dev);
1071         if (ret != 0)
1072                 return ret;
1073
1074         return ret;
1075 }
1076
1077
1078 /*
1079  * storvsc_command_completion - Command completion processing
1080  */
1081 static void storvsc_command_completion(struct hv_storvsc_request *request)
1082 {
1083         struct storvsc_cmd_request *cmd_request =
1084                 (struct storvsc_cmd_request *)request->context;
1085         struct scsi_cmnd *scmnd = cmd_request->cmd;
1086         struct hv_host_device *host_dev =
1087                 (struct hv_host_device *)scmnd->device->host->hostdata;
1088         void (*scsi_done_fn)(struct scsi_cmnd *);
1089         struct scsi_sense_hdr sense_hdr;
1090         struct vmscsi_request *vm_srb;
1091
1092         vm_srb = &request->vstor_packet.vm_srb;
1093         if (cmd_request->bounce_sgl_count) {
1094                 if (vm_srb->data_in == READ_TYPE) {
1095                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1096                                         cmd_request->bounce_sgl,
1097                                         scsi_sg_count(scmnd));
1098                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1099                                         cmd_request->bounce_sgl_count);
1100                 }
1101         }
1102
1103         /*
1104          * If there is an error; offline the device since all
1105          * error recovery strategies would have already been
1106          * deployed on the host side.
1107          */
1108         if (vm_srb->srb_status == 0x4)
1109                 scmnd->result = DID_TARGET_FAILURE << 16;
1110         else
1111                 scmnd->result = vm_srb->scsi_status;
1112
1113         if (scmnd->result) {
1114                 if (scsi_normalize_sense(scmnd->sense_buffer,
1115                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1116                         scsi_print_sense_hdr("storvsc", &sense_hdr);
1117         }
1118
1119         scsi_set_resid(scmnd,
1120                 request->data_buffer.len -
1121                 vm_srb->data_transfer_length);
1122
1123         scsi_done_fn = scmnd->scsi_done;
1124
1125         scmnd->host_scribble = NULL;
1126         scmnd->scsi_done = NULL;
1127
1128         scsi_done_fn(scmnd);
1129
1130         kmem_cache_free(host_dev->request_pool, cmd_request);
1131 }
1132
1133
1134 /*
1135  * storvsc_queuecommand - Initiate command processing
1136  */
1137 static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
1138                                 void (*done)(struct scsi_cmnd *))
1139 {
1140         int ret;
1141         struct hv_host_device *host_dev =
1142                 (struct hv_host_device *)scmnd->device->host->hostdata;
1143         struct hv_device *dev = host_dev->dev;
1144         struct hv_storvsc_request *request;
1145         struct storvsc_cmd_request *cmd_request;
1146         unsigned int request_size = 0;
1147         int i;
1148         struct scatterlist *sgl;
1149         unsigned int sg_count = 0;
1150         struct vmscsi_request *vm_srb;
1151
1152
1153         /* If retrying, no need to prep the cmd */
1154         if (scmnd->host_scribble) {
1155
1156                 cmd_request =
1157                         (struct storvsc_cmd_request *)scmnd->host_scribble;
1158
1159                 goto retry_request;
1160         }
1161
1162         scmnd->scsi_done = done;
1163
1164         request_size = sizeof(struct storvsc_cmd_request);
1165
1166         cmd_request = kmem_cache_zalloc(host_dev->request_pool,
1167                                        GFP_ATOMIC);
1168         if (!cmd_request) {
1169                 scmnd->scsi_done = NULL;
1170                 return SCSI_MLQUEUE_DEVICE_BUSY;
1171         }
1172
1173         /* Setup the cmd request */
1174         cmd_request->bounce_sgl_count = 0;
1175         cmd_request->bounce_sgl = NULL;
1176         cmd_request->cmd = scmnd;
1177
1178         scmnd->host_scribble = (unsigned char *)cmd_request;
1179
1180         request = &cmd_request->request;
1181         vm_srb = &request->vstor_packet.vm_srb;
1182
1183
1184         /* Build the SRB */
1185         switch (scmnd->sc_data_direction) {
1186         case DMA_TO_DEVICE:
1187                 vm_srb->data_in = WRITE_TYPE;
1188                 break;
1189         case DMA_FROM_DEVICE:
1190                 vm_srb->data_in = READ_TYPE;
1191                 break;
1192         default:
1193                 vm_srb->data_in = UNKNOWN_TYPE;
1194                 break;
1195         }
1196
1197         request->on_io_completion = storvsc_command_completion;
1198         request->context = cmd_request;/* scmnd; */
1199
1200         vm_srb->port_number = host_dev->port;
1201         vm_srb->path_id = scmnd->device->channel;
1202         vm_srb->target_id = scmnd->device->id;
1203         vm_srb->lun = scmnd->device->lun;
1204
1205         vm_srb->cdb_length = scmnd->cmd_len;
1206
1207         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1208
1209         request->sense_buffer = scmnd->sense_buffer;
1210
1211
1212         request->data_buffer.len = scsi_bufflen(scmnd);
1213         if (scsi_sg_count(scmnd)) {
1214                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1215                 sg_count = scsi_sg_count(scmnd);
1216
1217                 /* check if we need to bounce the sgl */
1218                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1219                         cmd_request->bounce_sgl =
1220                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1221                                                      scsi_bufflen(scmnd));
1222                         if (!cmd_request->bounce_sgl) {
1223                                 scmnd->scsi_done = NULL;
1224                                 scmnd->host_scribble = NULL;
1225                                 kmem_cache_free(host_dev->request_pool,
1226                                                 cmd_request);
1227
1228                                 return SCSI_MLQUEUE_HOST_BUSY;
1229                         }
1230
1231                         cmd_request->bounce_sgl_count =
1232                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1233                                         PAGE_SHIFT;
1234
1235                         if (vm_srb->data_in == WRITE_TYPE)
1236                                 copy_to_bounce_buffer(sgl,
1237                                         cmd_request->bounce_sgl,
1238                                         scsi_sg_count(scmnd));
1239
1240                         sgl = cmd_request->bounce_sgl;
1241                         sg_count = cmd_request->bounce_sgl_count;
1242                 }
1243
1244                 request->data_buffer.offset = sgl[0].offset;
1245
1246                 for (i = 0; i < sg_count; i++)
1247                         request->data_buffer.pfn_array[i] =
1248                                 page_to_pfn(sg_page((&sgl[i])));
1249
1250         } else if (scsi_sglist(scmnd)) {
1251                 request->data_buffer.offset =
1252                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1253                 request->data_buffer.pfn_array[0] =
1254                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1255         }
1256
1257 retry_request:
1258         /* Invokes the vsc to start an IO */
1259         ret = storvsc_do_io(dev, &cmd_request->request);
1260
1261         if (ret == -EAGAIN) {
1262                 /* no more space */
1263
1264                 if (cmd_request->bounce_sgl_count)
1265                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1266                                         cmd_request->bounce_sgl_count);
1267
1268                 kmem_cache_free(host_dev->request_pool, cmd_request);
1269
1270                 scmnd->scsi_done = NULL;
1271                 scmnd->host_scribble = NULL;
1272
1273                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1274         }
1275
1276         return ret;
1277 }
1278
1279 static DEF_SCSI_QCMD(storvsc_queuecommand)
1280
1281
1282 /* Scsi driver */
1283 static struct scsi_host_template scsi_driver = {
1284         .module =               THIS_MODULE,
1285         .name =                 "storvsc_host_t",
1286         .bios_param =           storvsc_get_chs,
1287         .queuecommand =         storvsc_queuecommand,
1288         .eh_host_reset_handler =        storvsc_host_reset_handler,
1289         .slave_alloc =          storvsc_device_alloc,
1290         .slave_configure =      storvsc_device_configure,
1291         .cmd_per_lun =          1,
1292         /* 64 max_queue * 1 target */
1293         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1294         .this_id =              -1,
1295         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1296         /* currently 32 */
1297         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1298         /*
1299          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
1300          * into 1 sg element. If set, we must limit the max_segment_size to
1301          * PAGE_SIZE, otherwise we may get 1 sg element that represents
1302          * multiple
1303          */
1304         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
1305         .use_clustering =       ENABLE_CLUSTERING,
1306         /* Make sure we dont get a sg segment crosses a page boundary */
1307         .dma_boundary =         PAGE_SIZE-1,
1308 };
1309
1310 enum {
1311         SCSI_GUID,
1312         IDE_GUID,
1313 };
1314
1315 static const struct hv_vmbus_device_id id_table[] = {
1316         /* SCSI guid */
1317         { VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
1318                        0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
1319           .driver_data = SCSI_GUID },
1320         /* IDE guid */
1321         { VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
1322                        0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
1323           .driver_data = IDE_GUID },
1324         { },
1325 };
1326
1327 MODULE_DEVICE_TABLE(vmbus, id_table);
1328
1329
1330 /*
1331  * storvsc_probe - Add a new device for this driver
1332  */
1333
1334 static int storvsc_probe(struct hv_device *device,
1335                         const struct hv_vmbus_device_id *dev_id)
1336 {
1337         int ret;
1338         struct Scsi_Host *host;
1339         struct hv_host_device *host_dev;
1340         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1341         int path = 0;
1342         int target = 0;
1343         struct storvsc_device *stor_device;
1344
1345         host = scsi_host_alloc(&scsi_driver,
1346                                sizeof(struct hv_host_device));
1347         if (!host)
1348                 return -ENOMEM;
1349
1350         dev_set_drvdata(&device->device, host);
1351
1352         host_dev = (struct hv_host_device *)host->hostdata;
1353         memset(host_dev, 0, sizeof(struct hv_host_device));
1354
1355         host_dev->port = host->host_no;
1356         host_dev->dev = device;
1357
1358         host_dev->request_pool =
1359                                 kmem_cache_create(dev_name(&device->device),
1360                                         sizeof(struct storvsc_cmd_request), 0,
1361                                         SLAB_HWCACHE_ALIGN, NULL);
1362
1363         if (!host_dev->request_pool) {
1364                 scsi_host_put(host);
1365                 return -ENOMEM;
1366         }
1367
1368         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1369         if (!stor_device) {
1370                 kmem_cache_destroy(host_dev->request_pool);
1371                 scsi_host_put(host);
1372                 return -ENOMEM;
1373         }
1374
1375         stor_device->destroy = false;
1376         init_waitqueue_head(&stor_device->waiting_to_drain);
1377         stor_device->device = device;
1378         device->ext = stor_device;
1379
1380         stor_device->port_number = host->host_no;
1381         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1382         if (ret) {
1383                 kmem_cache_destroy(host_dev->request_pool);
1384                 scsi_host_put(host);
1385                 kfree(stor_device);
1386                 return ret;
1387         }
1388
1389         if (dev_is_ide)
1390                 storvsc_get_ide_info(device, &target, &path);
1391
1392         host_dev->path = stor_device->path_id;
1393         host_dev->target = stor_device->target_id;
1394
1395         /* max # of devices per target */
1396         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1397         /* max # of targets per channel */
1398         host->max_id = STORVSC_MAX_TARGETS;
1399         /* max # of channels */
1400         host->max_channel = STORVSC_MAX_CHANNELS - 1;
1401         /* max cmd length */
1402         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1403
1404         /* Register the HBA and start the scsi bus scan */
1405         ret = scsi_add_host(host, &device->device);
1406         if (ret != 0)
1407                 goto err_out;
1408
1409         if (!dev_is_ide) {
1410                 scsi_scan_host(host);
1411                 return 0;
1412         }
1413         ret = scsi_add_device(host, 0, target, 0);
1414         if (ret) {
1415                 scsi_remove_host(host);
1416                 goto err_out;
1417         }
1418         return 0;
1419
1420 err_out:
1421         storvsc_dev_remove(device);
1422         kmem_cache_destroy(host_dev->request_pool);
1423         scsi_host_put(host);
1424         return -ENODEV;
1425 }
1426
1427 /* The one and only one */
1428
1429 static struct hv_driver storvsc_drv = {
1430         .name = "storvsc",
1431         .id_table = id_table,
1432         .probe = storvsc_probe,
1433         .remove = storvsc_remove,
1434 };
1435
1436 static int __init storvsc_drv_init(void)
1437 {
1438         u32 max_outstanding_req_per_channel;
1439
1440         /*
1441          * Divide the ring buffer data size (which is 1 page less
1442          * than the ring buffer size since that page is reserved for
1443          * the ring buffer indices) by the max request size (which is
1444          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1445          */
1446         max_outstanding_req_per_channel =
1447                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1448                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1449                 sizeof(struct vstor_packet) + sizeof(u64),
1450                 sizeof(u64)));
1451
1452         if (max_outstanding_req_per_channel <
1453             STORVSC_MAX_IO_REQUESTS)
1454                 return -EINVAL;
1455
1456         return vmbus_driver_register(&storvsc_drv);
1457 }
1458
1459 static void __exit storvsc_drv_exit(void)
1460 {
1461         vmbus_driver_unregister(&storvsc_drv);
1462 }
1463
1464 MODULE_LICENSE("GPL");
1465 MODULE_VERSION(HV_DRV_VERSION);
1466 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1467 module_init(storvsc_drv_init);
1468 module_exit(storvsc_drv_exit);