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 <linux/hyperv.h>
  35 #include <linux/mempool.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_tcq.h>
  41 #include <scsi/scsi_eh.h>
  42 #include <scsi/scsi_devinfo.h>
  43 #include <scsi/scsi_dbg.h>
  44
  45
  46 #define STORVSC_MIN_BUF_NR                              64
  47 #define STORVSC_RING_BUFFER_SIZE                        (20*PAGE_SIZE)
  48 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
  49
  50 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
  51 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
  52
  53 /* to alert the user that structure sizes may be mismatched even though the */
  54 /* protocol versions match. */
  55
  56
  57 #define REVISION_STRING(REVISION_) #REVISION_
  58 #define FILL_VMSTOR_REVISION(RESULT_LVALUE_)                            \
  59         do {                                                            \
  60                 char *revision_string                                   \
  61                         = REVISION_STRING($Rev : 6 $) + 6;              \
  62                 RESULT_LVALUE_ = 0;                                     \
  63                 while (*revision_string >= '0'                          \
  64                         && *revision_string <= '9') {                   \
  65                         RESULT_LVALUE_ *= 10;                           \
  66                         RESULT_LVALUE_ += *revision_string - '0';       \
  67                         revision_string++;                              \
  68                 }                                                       \
  69         } while (0)
  70
  71 /* Major/minor macros.  Minor version is in LSB, meaning that earlier flat */
  72 /* version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1). */
  73 #define VMSTOR_PROTOCOL_MAJOR(VERSION_)         (((VERSION_) >> 8) & 0xff)
  74 #define VMSTOR_PROTOCOL_MINOR(VERSION_)         (((VERSION_))      & 0xff)
  75 #define VMSTOR_PROTOCOL_VERSION(MAJOR_, MINOR_) ((((MAJOR_) & 0xff) << 8) | \
  76                                                  (((MINOR_) & 0xff)))
  77 #define VMSTOR_INVALID_PROTOCOL_VERSION         (-1)
  78
  79 /* Version history: */
  80 /* V1 Beta                    0.1 */
  81 /* V1 RC < 2008/1/31          1.0 */
  82 /* V1 RC > 2008/1/31          2.0 */
  83 #define VMSTOR_PROTOCOL_VERSION_CURRENT VMSTOR_PROTOCOL_VERSION(4, 2)
  84
  85
  86
  87
  88 /*  This will get replaced with the max transfer length that is possible on */
  89 /*  the host adapter. */
  90 /*  The max transfer length will be published when we offer a vmbus channel. */
  91 #define MAX_TRANSFER_LENGTH     0x40000
  92 #define DEFAULT_PACKET_SIZE (sizeof(struct vmdata_gpa_direct) + \
  93                         sizeof(struct vstor_packet) +           \
  94                         sizesizeof(u64) * (MAX_TRANSFER_LENGTH / PAGE_SIZE)))
  95
  96
  97 /*  Packet structure describing virtual storage requests. */
  98 enum vstor_packet_operation {
  99         VSTOR_OPERATION_COMPLETE_IO             = 1,
 100         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
 101         VSTOR_OPERATION_EXECUTE_SRB             = 3,
 102         VSTOR_OPERATION_RESET_LUN               = 4,
 103         VSTOR_OPERATION_RESET_ADAPTER           = 5,
 104         VSTOR_OPERATION_RESET_BUS               = 6,
 105         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
 106         VSTOR_OPERATION_END_INITIALIZATION      = 8,
 107         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
 108         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
 109         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
 110         VSTOR_OPERATION_MAXIMUM                 = 11
 111 };
 112
 113 /*
 114  * Platform neutral description of a scsi request -
 115  * this remains the same across the write regardless of 32/64 bit
 116  * note: it's patterned off the SCSI_PASS_THROUGH structure
 117  */
 118 #define CDB16GENERIC_LENGTH                     0x10
 119
 120 #ifndef SENSE_BUFFER_SIZE
 121 #define SENSE_BUFFER_SIZE                       0x12
 122 #endif
 123
 124 #define MAX_DATA_BUF_LEN_WITH_PADDING           0x14
 125
 126 struct vmscsi_request {
 127         unsigned short length;
 128         unsigned char srb_status;
 129         unsigned char scsi_status;
 130
 131         unsigned char port_number;
 132         unsigned char path_id;
 133         unsigned char target_id;
 134         unsigned char lun;
 135
 136         unsigned char cdb_length;
 137         unsigned char sense_info_length;
 138         unsigned char data_in;
 139         unsigned char reserved;
 140
 141         unsigned int data_transfer_length;
 142
 143         union {
 144                 unsigned char cdb[CDB16GENERIC_LENGTH];
 145                 unsigned char sense_data[SENSE_BUFFER_SIZE];
 146                 unsigned char reserved_array[MAX_DATA_BUF_LEN_WITH_PADDING];
 147         };
 148 } __attribute((packed));
 149
 150
 151 /*
 152  * This structure is sent during the intialization phase to get the different
 153  * properties of the channel.
 154  */
 155 struct vmstorage_channel_properties {
 156         unsigned short protocol_version;
 157         unsigned char path_id;
 158         unsigned char target_id;
 159
 160         /* Note: port number is only really known on the client side */
 161         unsigned int port_number;
 162         unsigned int flags;
 163         unsigned int max_transfer_bytes;
 164
 165         /*  This id is unique for each channel and will correspond with */
 166         /*  vendor specific data in the inquirydata */
 167         unsigned long long unique_id;
 168 } __packed;
 169
 170 /*  This structure is sent during the storage protocol negotiations. */
 171 struct vmstorage_protocol_version {
 172         /* Major (MSW) and minor (LSW) version numbers. */
 173         unsigned short major_minor;
 174
 175         /*
 176          * Revision number is auto-incremented whenever this file is changed
 177          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 178          * definitely indicate incompatibility--but it does indicate mismatched
 179          * builds.
 180          */
 181         unsigned short revision;
 182 } __packed;
 183
 184 /* Channel Property Flags */
 185 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 186 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 187
 188 struct vstor_packet {
 189         /* Requested operation type */
 190         enum vstor_packet_operation operation;
 191
 192         /*  Flags - see below for values */
 193         unsigned int flags;
 194
 195         /* Status of the request returned from the server side. */
 196         unsigned int status;
 197
 198         /* Data payload area */
 199         union {
 200                 /*
 201                  * Structure used to forward SCSI commands from the
 202                  * client to the server.
 203                  */
 204                 struct vmscsi_request vm_srb;
 205
 206                 /* Structure used to query channel properties. */
 207                 struct vmstorage_channel_properties storage_channel_properties;
 208
 209                 /* Used during version negotiations. */
 210                 struct vmstorage_protocol_version version;
 211         };
 212 } __packed;
 213
 214 /* Packet flags */
 215 /*
 216  * This flag indicates that the server should send back a completion for this
 217  * packet.
 218  */
 219 #define REQUEST_COMPLETION_FLAG 0x1
 220
 221 /*  This is the set of flags that the vsc can set in any packets it sends */
 222 #define VSC_LEGAL_FLAGS         (REQUEST_COMPLETION_FLAG)
 223
 224
 225 /* Defines */
 226
 227 #define STORVSC_MAX_IO_REQUESTS                         128
 228
 229 /*
 230  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
 231  * reality, the path/target is not used (ie always set to 0) so our
 232  * scsi host adapter essentially has 1 bus with 1 target that contains
 233  * up to 256 luns.
 234  */
 235 #define STORVSC_MAX_LUNS_PER_TARGET                     64
 236 #define STORVSC_MAX_TARGETS                             1
 237 #define STORVSC_MAX_CHANNELS                            1
 238 #define STORVSC_MAX_CMD_LEN                             16
 239
 240 /* Matches Windows-end */
 241 enum storvsc_request_type {
 242         WRITE_TYPE,
 243         READ_TYPE,
 244         UNKNOWN_TYPE,
 245 };
 246
 247
 248 struct hv_storvsc_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 /* A storvsc device is a device object that contains a vmbus channel */
 264 struct storvsc_device {
 265         struct hv_device *device;
 266
 267         bool     destroy;
 268         bool     drain_notify;
 269         atomic_t num_outstanding_req;
 270         struct Scsi_Host *host;
 271
 272         wait_queue_head_t waiting_to_drain;
 273
 274         /*
 275          * Each unique Port/Path/Target represents 1 channel ie scsi
 276          * controller. In reality, the pathid, targetid is always 0
 277          * and the port is set by us
 278          */
 279         unsigned int port_number;
 280         unsigned char path_id;
 281         unsigned char target_id;
 282
 283         /* Used for vsc/vsp channel reset process */
 284         struct hv_storvsc_request init_request;
 285         struct hv_storvsc_request reset_request;
 286 };
 287
 288 struct hv_host_device {
 289         struct hv_device *dev;
 290         struct kmem_cache *request_pool;
 291         mempool_t *request_mempool;
 292         unsigned int port;
 293         unsigned char path;
 294         unsigned char target;
 295 };
 296
 297 struct storvsc_cmd_request {
 298         struct list_head entry;
 299         struct scsi_cmnd *cmd;
 300
 301         unsigned int bounce_sgl_count;
 302         struct scatterlist *bounce_sgl;
 303
 304         struct hv_storvsc_request request;
 305 };
 306
 307 struct storvsc_scan_work {
 308         struct work_struct work;
 309         struct Scsi_Host *host;
 310         uint lun;
 311 };
 312
 313 static void storvsc_bus_scan(struct work_struct *work)
 314 {
 315         struct storvsc_scan_work *wrk;
 316         int id, order_id;
 317
 318         wrk = container_of(work, struct storvsc_scan_work, work);
 319         for (id = 0; id < wrk->host->max_id; ++id) {
 320                 if (wrk->host->reverse_ordering)
 321                         order_id = wrk->host->max_id - id - 1;
 322                 else
 323                         order_id = id;
 324
 325                 scsi_scan_target(&wrk->host->shost_gendev, 0,
 326                                 order_id, SCAN_WILD_CARD, 1);
 327         }
 328         kfree(wrk);
 329 }
 330
 331 static inline struct storvsc_device *get_out_stor_device(
 332                                         struct hv_device *device)
 333 {
 334         struct storvsc_device *stor_device;
 335
 336         stor_device = hv_get_drvdata(device);
 337
 338         if (stor_device && stor_device->destroy)
 339                 stor_device = NULL;
 340
 341         return stor_device;
 342 }
 343
 344
 345 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 346 {
 347         dev->drain_notify = true;
 348         wait_event(dev->waiting_to_drain,
 349                    atomic_read(&dev->num_outstanding_req) == 0);
 350         dev->drain_notify = false;
 351 }
 352
 353 static inline struct storvsc_device *get_in_stor_device(
 354                                         struct hv_device *device)
 355 {
 356         struct storvsc_device *stor_device;
 357
 358         stor_device = hv_get_drvdata(device);
 359
 360         if (!stor_device)
 361                 goto get_in_err;
 362
 363         /*
 364          * If the device is being destroyed; allow incoming
 365          * traffic only to cleanup outstanding requests.
 366          */
 367
 368         if (stor_device->destroy  &&
 369                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 370                 stor_device = NULL;
 371
 372 get_in_err:
 373         return stor_device;
 374
 375 }
 376
 377 static int storvsc_channel_init(struct hv_device *device)
 378 {
 379         struct storvsc_device *stor_device;
 380         struct hv_storvsc_request *request;
 381         struct vstor_packet *vstor_packet;
 382         int ret, t;
 383
 384         stor_device = get_out_stor_device(device);
 385         if (!stor_device)
 386                 return -ENODEV;
 387
 388         request = &stor_device->init_request;
 389         vstor_packet = &request->vstor_packet;
 390
 391         /*
 392          * Now, initiate the vsc/vsp initialization protocol on the open
 393          * channel
 394          */
 395         memset(request, 0, sizeof(struct hv_storvsc_request));
 396         init_completion(&request->wait_event);
 397         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 398         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 399
 400         ret = vmbus_sendpacket(device->channel, vstor_packet,
 401                                sizeof(struct vstor_packet),
 402                                (unsigned long)request,
 403                                VM_PKT_DATA_INBAND,
 404                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 405         if (ret != 0)
 406                 goto cleanup;
 407
 408         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 409         if (t == 0) {
 410                 ret = -ETIMEDOUT;
 411                 goto cleanup;
 412         }
 413
 414         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 415             vstor_packet->status != 0)
 416                 goto cleanup;
 417
 418
 419         /* reuse the packet for version range supported */
 420         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 421         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 422         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 423
 424         vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
 425         FILL_VMSTOR_REVISION(vstor_packet->version.revision);
 426
 427         ret = vmbus_sendpacket(device->channel, vstor_packet,
 428                                sizeof(struct vstor_packet),
 429                                (unsigned long)request,
 430                                VM_PKT_DATA_INBAND,
 431                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 432         if (ret != 0)
 433                 goto cleanup;
 434
 435         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 436         if (t == 0) {
 437                 ret = -ETIMEDOUT;
 438                 goto cleanup;
 439         }
 440
 441         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 442             vstor_packet->status != 0)
 443                 goto cleanup;
 444
 445
 446         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 447         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 448         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 449         vstor_packet->storage_channel_properties.port_number =
 450                                         stor_device->port_number;
 451
 452         ret = vmbus_sendpacket(device->channel, vstor_packet,
 453                                sizeof(struct vstor_packet),
 454                                (unsigned long)request,
 455                                VM_PKT_DATA_INBAND,
 456                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 457
 458         if (ret != 0)
 459                 goto cleanup;
 460
 461         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 462         if (t == 0) {
 463                 ret = -ETIMEDOUT;
 464                 goto cleanup;
 465         }
 466
 467         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 468             vstor_packet->status != 0)
 469                 goto cleanup;
 470
 471         stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
 472         stor_device->target_id
 473                 = vstor_packet->storage_channel_properties.target_id;
 474
 475         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 476         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 477         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 478
 479         ret = vmbus_sendpacket(device->channel, vstor_packet,
 480                                sizeof(struct vstor_packet),
 481                                (unsigned long)request,
 482                                VM_PKT_DATA_INBAND,
 483                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 484
 485         if (ret != 0)
 486                 goto cleanup;
 487
 488         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 489         if (t == 0) {
 490                 ret = -ETIMEDOUT;
 491                 goto cleanup;
 492         }
 493
 494         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 495             vstor_packet->status != 0)
 496                 goto cleanup;
 497
 498
 499 cleanup:
 500         return ret;
 501 }
 502
 503 static void storvsc_on_io_completion(struct hv_device *device,
 504                                   struct vstor_packet *vstor_packet,
 505                                   struct hv_storvsc_request *request)
 506 {
 507         struct storvsc_device *stor_device;
 508         struct vstor_packet *stor_pkt;
 509
 510         stor_device = hv_get_drvdata(device);
 511         stor_pkt = &request->vstor_packet;
 512
 513         /*
 514          * The current SCSI handling on the host side does
 515          * not correctly handle:
 516          * INQUIRY command with page code parameter set to 0x80
 517          * MODE_SENSE command with cmd[2] == 0x1c
 518          *
 519          * Setup srb and scsi status so this won't be fatal.
 520          * We do this so we can distinguish truly fatal failues
 521          * (srb status == 0x4) and off-line the device in that case.
 522          */
 523
 524         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
 525                 (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
 526                 vstor_packet->vm_srb.scsi_status = 0;
 527                 vstor_packet->vm_srb.srb_status = 0x1;
 528         }
 529
 530
 531         /* Copy over the status...etc */
 532         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 533         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 534         stor_pkt->vm_srb.sense_info_length =
 535         vstor_packet->vm_srb.sense_info_length;
 536
 537         if (vstor_packet->vm_srb.scsi_status != 0 ||
 538                 vstor_packet->vm_srb.srb_status != 1){
 539                 dev_warn(&device->device,
 540                          "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 541                          stor_pkt->vm_srb.cdb[0],
 542                          vstor_packet->vm_srb.scsi_status,
 543                          vstor_packet->vm_srb.srb_status);
 544         }
 545
 546         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 547                 /* CHECK_CONDITION */
 548                 if (vstor_packet->vm_srb.srb_status & 0x80) {
 549                         /* autosense data available */
 550                         dev_warn(&device->device,
 551                                  "stor pkt %p autosense data valid - len %d\n",
 552                                  request,
 553                                  vstor_packet->vm_srb.sense_info_length);
 554
 555                         memcpy(request->sense_buffer,
 556                                vstor_packet->vm_srb.sense_data,
 557                                vstor_packet->vm_srb.sense_info_length);
 558
 559                 }
 560         }
 561
 562         stor_pkt->vm_srb.data_transfer_length =
 563         vstor_packet->vm_srb.data_transfer_length;
 564
 565         request->on_io_completion(request);
 566
 567         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 568                 stor_device->drain_notify)
 569                 wake_up(&stor_device->waiting_to_drain);
 570
 571
 572 }
 573
 574 static void storvsc_on_receive(struct hv_device *device,
 575                              struct vstor_packet *vstor_packet,
 576                              struct hv_storvsc_request *request)
 577 {
 578         struct storvsc_scan_work *work;
 579         struct storvsc_device *stor_device;
 580
 581         switch (vstor_packet->operation) {
 582         case VSTOR_OPERATION_COMPLETE_IO:
 583                 storvsc_on_io_completion(device, vstor_packet, request);
 584                 break;
 585
 586         case VSTOR_OPERATION_REMOVE_DEVICE:
 587         case VSTOR_OPERATION_ENUMERATE_BUS:
 588                 stor_device = get_in_stor_device(device);
 589                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 590                 if (!work)
 591                         return;
 592
 593                 INIT_WORK(&work->work, storvsc_bus_scan);
 594                 work->host = stor_device->host;
 595                 schedule_work(&work->work);
 596                 break;
 597
 598         default:
 599                 break;
 600         }
 601 }
 602
 603 static void storvsc_on_channel_callback(void *context)
 604 {
 605         struct hv_device *device = (struct hv_device *)context;
 606         struct storvsc_device *stor_device;
 607         u32 bytes_recvd;
 608         u64 request_id;
 609         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 610         struct hv_storvsc_request *request;
 611         int ret;
 612
 613
 614         stor_device = get_in_stor_device(device);
 615         if (!stor_device)
 616                 return;
 617
 618         do {
 619                 ret = vmbus_recvpacket(device->channel, packet,
 620                                        ALIGN(sizeof(struct vstor_packet), 8),
 621                                        &bytes_recvd, &request_id);
 622                 if (ret == 0 && bytes_recvd > 0) {
 623
 624                         request = (struct hv_storvsc_request *)
 625                                         (unsigned long)request_id;
 626
 627                         if ((request == &stor_device->init_request) ||
 628                             (request == &stor_device->reset_request)) {
 629
 630                                 memcpy(&request->vstor_packet, packet,
 631                                        sizeof(struct vstor_packet));
 632                                 complete(&request->wait_event);
 633                         } else {
 634                                 storvsc_on_receive(device,
 635                                                 (struct vstor_packet *)packet,
 636                                                 request);
 637                         }
 638                 } else {
 639                         break;
 640                 }
 641         } while (1);
 642
 643         return;
 644 }
 645
 646 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 647 {
 648         struct vmstorage_channel_properties props;
 649         int ret;
 650
 651         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 652
 653         /* Open the channel */
 654         ret = vmbus_open(device->channel,
 655                          ring_size,
 656                          ring_size,
 657                          (void *)&props,
 658                          sizeof(struct vmstorage_channel_properties),
 659                          storvsc_on_channel_callback, device);
 660
 661         if (ret != 0)
 662                 return ret;
 663
 664         ret = storvsc_channel_init(device);
 665
 666         return ret;
 667 }
 668
 669 static int storvsc_dev_remove(struct hv_device *device)
 670 {
 671         struct storvsc_device *stor_device;
 672         unsigned long flags;
 673
 674         stor_device = hv_get_drvdata(device);
 675
 676         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 677         stor_device->destroy = true;
 678         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 679
 680         /*
 681          * At this point, all outbound traffic should be disable. We
 682          * only allow inbound traffic (responses) to proceed so that
 683          * outstanding requests can be completed.
 684          */
 685
 686         storvsc_wait_to_drain(stor_device);
 687
 688         /*
 689          * Since we have already drained, we don't need to busy wait
 690          * as was done in final_release_stor_device()
 691          * Note that we cannot set the ext pointer to NULL until
 692          * we have drained - to drain the outgoing packets, we need to
 693          * allow incoming packets.
 694          */
 695         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 696         hv_set_drvdata(device, NULL);
 697         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 698
 699         /* Close the channel */
 700         vmbus_close(device->channel);
 701
 702         kfree(stor_device);
 703         return 0;
 704 }
 705
 706 static int storvsc_do_io(struct hv_device *device,
 707                               struct hv_storvsc_request *request)
 708 {
 709         struct storvsc_device *stor_device;
 710         struct vstor_packet *vstor_packet;
 711         int ret = 0;
 712
 713         vstor_packet = &request->vstor_packet;
 714         stor_device = get_out_stor_device(device);
 715
 716         if (!stor_device)
 717                 return -ENODEV;
 718
 719
 720         request->device  = device;
 721
 722
 723         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
 724
 725         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
 726
 727
 728         vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
 729
 730
 731         vstor_packet->vm_srb.data_transfer_length =
 732         request->data_buffer.len;
 733
 734         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 735
 736         if (request->data_buffer.len) {
 737                 ret = vmbus_sendpacket_multipagebuffer(device->channel,
 738                                 &request->data_buffer,
 739                                 vstor_packet,
 740                                 sizeof(struct vstor_packet),
 741                                 (unsigned long)request);
 742         } else {
 743                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 744                                sizeof(struct vstor_packet),
 745                                (unsigned long)request,
 746                                VM_PKT_DATA_INBAND,
 747                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 748         }
 749
 750         if (ret != 0)
 751                 return ret;
 752
 753         atomic_inc(&stor_device->num_outstanding_req);
 754
 755         return ret;
 756 }
 757
 758 static void storvsc_get_ide_info(struct hv_device *dev, int *target, int *path)
 759 {
 760         *target =
 761                 dev->dev_instance.b[5] << 8 | dev->dev_instance.b[4];
 762
 763         *path =
 764                 dev->dev_instance.b[3] << 24 |
 765                 dev->dev_instance.b[2] << 16 |
 766                 dev->dev_instance.b[1] << 8  | dev->dev_instance.b[0];
 767 }
 768
 769
 770 static int storvsc_device_alloc(struct scsi_device *sdevice)
 771 {
 772         /*
 773          * This enables luns to be located sparsely. Otherwise, we may not
 774          * discovered them.
 775          */
 776         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 777         return 0;
 778 }
 779
 780 static int storvsc_merge_bvec(struct request_queue *q,
 781                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 782 {
 783         /* checking done by caller. */
 784         return bvec->bv_len;
 785 }
 786
 787 static int storvsc_device_configure(struct scsi_device *sdevice)
 788 {
 789         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 790                                 STORVSC_MAX_IO_REQUESTS);
 791
 792         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 793
 794         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 795
 796         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 797
 798         return 0;
 799 }
 800
 801 static void destroy_bounce_buffer(struct scatterlist *sgl,
 802                                   unsigned int sg_count)
 803 {
 804         int i;
 805         struct page *page_buf;
 806
 807         for (i = 0; i < sg_count; i++) {
 808                 page_buf = sg_page((&sgl[i]));
 809                 if (page_buf != NULL)
 810                         __free_page(page_buf);
 811         }
 812
 813         kfree(sgl);
 814 }
 815
 816 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 817 {
 818         int i;
 819
 820         /* No need to check */
 821         if (sg_count < 2)
 822                 return -1;
 823
 824         /* We have at least 2 sg entries */
 825         for (i = 0; i < sg_count; i++) {
 826                 if (i == 0) {
 827                         /* make sure 1st one does not have hole */
 828                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 829                                 return i;
 830                 } else if (i == sg_count - 1) {
 831                         /* make sure last one does not have hole */
 832                         if (sgl[i].offset != 0)
 833                                 return i;
 834                 } else {
 835                         /* make sure no hole in the middle */
 836                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 837                                 return i;
 838                 }
 839         }
 840         return -1;
 841 }
 842
 843 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 844                                                 unsigned int sg_count,
 845                                                 unsigned int len)
 846 {
 847         int i;
 848         int num_pages;
 849         struct scatterlist *bounce_sgl;
 850         struct page *page_buf;
 851
 852         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 853
 854         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 855         if (!bounce_sgl)
 856                 return NULL;
 857
 858         for (i = 0; i < num_pages; i++) {
 859                 page_buf = alloc_page(GFP_ATOMIC);
 860                 if (!page_buf)
 861                         goto cleanup;
 862                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 863         }
 864
 865         return bounce_sgl;
 866
 867 cleanup:
 868         destroy_bounce_buffer(bounce_sgl, num_pages);
 869         return NULL;
 870 }
 871
 872
 873 /* Assume the original sgl has enough room */
 874 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 875                                             struct scatterlist *bounce_sgl,
 876                                             unsigned int orig_sgl_count)
 877 {
 878         int i;
 879         int j = 0;
 880         unsigned long src, dest;
 881         unsigned int srclen, destlen, copylen;
 882         unsigned int total_copied = 0;
 883         unsigned long bounce_addr = 0;
 884         unsigned long dest_addr = 0;
 885         unsigned long flags;
 886
 887         local_irq_save(flags);
 888
 889         for (i = 0; i < orig_sgl_count; i++) {
 890                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 891                                         KM_IRQ0) + orig_sgl[i].offset;
 892                 dest = dest_addr;
 893                 destlen = orig_sgl[i].length;
 894
 895                 if (bounce_addr == 0)
 896                         bounce_addr =
 897                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 898                                                         KM_IRQ0);
 899
 900                 while (destlen) {
 901                         src = bounce_addr + bounce_sgl[j].offset;
 902                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 903
 904                         copylen = min(srclen, destlen);
 905                         memcpy((void *)dest, (void *)src, copylen);
 906
 907                         total_copied += copylen;
 908                         bounce_sgl[j].offset += copylen;
 909                         destlen -= copylen;
 910                         dest += copylen;
 911
 912                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 913                                 /* full */
 914                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 915                                 j++;
 916
 917                                 /* if we need to use another bounce buffer */
 918                                 if (destlen || i != orig_sgl_count - 1)
 919                                         bounce_addr =
 920                                         (unsigned long)kmap_atomic(
 921                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 922                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 923                                 /* unmap the last bounce that is < PAGE_SIZE */
 924                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 925                         }
 926                 }
 927
 928                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 929                               KM_IRQ0);
 930         }
 931
 932         local_irq_restore(flags);
 933
 934         return total_copied;
 935 }
 936
 937
 938 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 939 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 940                                           struct scatterlist *bounce_sgl,
 941                                           unsigned int orig_sgl_count)
 942 {
 943         int i;
 944         int j = 0;
 945         unsigned long src, dest;
 946         unsigned int srclen, destlen, copylen;
 947         unsigned int total_copied = 0;
 948         unsigned long bounce_addr = 0;
 949         unsigned long src_addr = 0;
 950         unsigned long flags;
 951
 952         local_irq_save(flags);
 953
 954         for (i = 0; i < orig_sgl_count; i++) {
 955                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 956                                 KM_IRQ0) + orig_sgl[i].offset;
 957                 src = src_addr;
 958                 srclen = orig_sgl[i].length;
 959
 960                 if (bounce_addr == 0)
 961                         bounce_addr =
 962                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 963                                                 KM_IRQ0);
 964
 965                 while (srclen) {
 966                         /* assume bounce offset always == 0 */
 967                         dest = bounce_addr + bounce_sgl[j].length;
 968                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 969
 970                         copylen = min(srclen, destlen);
 971                         memcpy((void *)dest, (void *)src, copylen);
 972
 973                         total_copied += copylen;
 974                         bounce_sgl[j].length += copylen;
 975                         srclen -= copylen;
 976                         src += copylen;
 977
 978                         if (bounce_sgl[j].length == PAGE_SIZE) {
 979                                 /* full..move to next entry */
 980                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 981                                 j++;
 982
 983                                 /* if we need to use another bounce buffer */
 984                                 if (srclen || i != orig_sgl_count - 1)
 985                                         bounce_addr =
 986                                         (unsigned long)kmap_atomic(
 987                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 988
 989                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 990                                 /* unmap the last bounce that is < PAGE_SIZE */
 991                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 992                         }
 993                 }
 994
 995                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 996         }
 997
 998         local_irq_restore(flags);
 999
1000         return total_copied;
1001 }
1002
1003
1004 static int storvsc_remove(struct hv_device *dev)
1005 {
1006         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1007         struct Scsi_Host *host = stor_device->host;
1008         struct hv_host_device *host_dev = shost_priv(host);
1009
1010         scsi_remove_host(host);
1011
1012         scsi_host_put(host);
1013
1014         storvsc_dev_remove(dev);
1015         if (host_dev->request_pool) {
1016                 mempool_destroy(host_dev->request_mempool);
1017                 kmem_cache_destroy(host_dev->request_pool);
1018                 host_dev->request_pool = NULL;
1019                 host_dev->request_mempool = NULL;
1020         }
1021         return 0;
1022 }
1023
1024
1025 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1026                            sector_t capacity, int *info)
1027 {
1028         sector_t nsect = capacity;
1029         sector_t cylinders = nsect;
1030         int heads, sectors_pt;
1031
1032         /*
1033          * We are making up these values; let us keep it simple.
1034          */
1035         heads = 0xff;
1036         sectors_pt = 0x3f;      /* Sectors per track */
1037         sector_div(cylinders, heads * sectors_pt);
1038         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1039                 cylinders = 0xffff;
1040
1041         info[0] = heads;
1042         info[1] = sectors_pt;
1043         info[2] = (int)cylinders;
1044
1045         return 0;
1046 }
1047
1048 static int storvsc_host_reset(struct hv_device *device)
1049 {
1050         struct storvsc_device *stor_device;
1051         struct hv_storvsc_request *request;
1052         struct vstor_packet *vstor_packet;
1053         int ret, t;
1054
1055
1056         stor_device = get_out_stor_device(device);
1057         if (!stor_device)
1058                 return FAILED;
1059
1060         request = &stor_device->reset_request;
1061         vstor_packet = &request->vstor_packet;
1062
1063         init_completion(&request->wait_event);
1064
1065         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1066         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1067         vstor_packet->vm_srb.path_id = stor_device->path_id;
1068
1069         ret = vmbus_sendpacket(device->channel, vstor_packet,
1070                                sizeof(struct vstor_packet),
1071                                (unsigned long)&stor_device->reset_request,
1072                                VM_PKT_DATA_INBAND,
1073                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1074         if (ret != 0)
1075                 return FAILED;
1076
1077         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1078         if (t == 0)
1079                 return TIMEOUT_ERROR;
1080
1081
1082         /*
1083          * At this point, all outstanding requests in the adapter
1084          * should have been flushed out and return to us
1085          */
1086
1087         return SUCCESS;
1088 }
1089
1090
1091 /*
1092  * storvsc_host_reset_handler - Reset the scsi HBA
1093  */
1094 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1095 {
1096         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1097         struct hv_device *dev = host_dev->dev;
1098
1099         return storvsc_host_reset(dev);
1100 }
1101
1102
1103 /*
1104  * storvsc_command_completion - Command completion processing
1105  */
1106 static void storvsc_command_completion(struct hv_storvsc_request *request)
1107 {
1108         struct storvsc_cmd_request *cmd_request =
1109                 (struct storvsc_cmd_request *)request->context;
1110         struct scsi_cmnd *scmnd = cmd_request->cmd;
1111         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1112         void (*scsi_done_fn)(struct scsi_cmnd *);
1113         struct scsi_sense_hdr sense_hdr;
1114         struct vmscsi_request *vm_srb;
1115
1116         vm_srb = &request->vstor_packet.vm_srb;
1117         if (cmd_request->bounce_sgl_count) {
1118                 if (vm_srb->data_in == READ_TYPE) {
1119                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1120                                         cmd_request->bounce_sgl,
1121                                         scsi_sg_count(scmnd));
1122                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1123                                         cmd_request->bounce_sgl_count);
1124                 }
1125         }
1126
1127         /*
1128          * If there is an error; offline the device since all
1129          * error recovery strategies would have already been
1130          * deployed on the host side.
1131          */
1132         if (vm_srb->srb_status == 0x4)
1133                 scmnd->result = DID_TARGET_FAILURE << 16;
1134         else
1135                 scmnd->result = vm_srb->scsi_status;
1136
1137         if (scmnd->result) {
1138                 if (scsi_normalize_sense(scmnd->sense_buffer,
1139                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1140                         scsi_print_sense_hdr("storvsc", &sense_hdr);
1141         }
1142
1143         scsi_set_resid(scmnd,
1144                 request->data_buffer.len -
1145                 vm_srb->data_transfer_length);
1146
1147         scsi_done_fn = scmnd->scsi_done;
1148
1149         scmnd->host_scribble = NULL;
1150         scmnd->scsi_done = NULL;
1151
1152         scsi_done_fn(scmnd);
1153
1154         mempool_free(cmd_request, host_dev->request_mempool);
1155 }
1156
1157 static bool storvsc_check_scsi_cmd(struct scsi_cmnd *scmnd)
1158 {
1159         bool allowed = true;
1160         u8 scsi_op = scmnd->cmnd[0];
1161
1162         switch (scsi_op) {
1163         /* smartd sends this command, which will offline the device */
1164         case SET_WINDOW:
1165                 scmnd->result = ILLEGAL_REQUEST << 16;
1166                 allowed = false;
1167                 break;
1168         default:
1169                 break;
1170         }
1171         return allowed;
1172 }
1173
1174 /*
1175  * storvsc_queuecommand - Initiate command processing
1176  */
1177 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1178 {
1179         int ret;
1180         struct hv_host_device *host_dev = shost_priv(host);
1181         struct hv_device *dev = host_dev->dev;
1182         struct hv_storvsc_request *request;
1183         struct storvsc_cmd_request *cmd_request;
1184         unsigned int request_size = 0;
1185         int i;
1186         struct scatterlist *sgl;
1187         unsigned int sg_count = 0;
1188         struct vmscsi_request *vm_srb;
1189
1190         if (storvsc_check_scsi_cmd(scmnd) == false) {
1191                 scmnd->scsi_done(scmnd);
1192                 return 0;
1193         }
1194
1195         /* If retrying, no need to prep the cmd */
1196         if (scmnd->host_scribble) {
1197
1198                 cmd_request =
1199                         (struct storvsc_cmd_request *)scmnd->host_scribble;
1200
1201                 goto retry_request;
1202         }
1203
1204         request_size = sizeof(struct storvsc_cmd_request);
1205
1206         cmd_request = mempool_alloc(host_dev->request_mempool,
1207                                        GFP_ATOMIC);
1208         if (!cmd_request)
1209                 return SCSI_MLQUEUE_DEVICE_BUSY;
1210
1211         memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
1212
1213         /* Setup the cmd request */
1214         cmd_request->bounce_sgl_count = 0;
1215         cmd_request->bounce_sgl = NULL;
1216         cmd_request->cmd = scmnd;
1217
1218         scmnd->host_scribble = (unsigned char *)cmd_request;
1219
1220         request = &cmd_request->request;
1221         vm_srb = &request->vstor_packet.vm_srb;
1222
1223
1224         /* Build the SRB */
1225         switch (scmnd->sc_data_direction) {
1226         case DMA_TO_DEVICE:
1227                 vm_srb->data_in = WRITE_TYPE;
1228                 break;
1229         case DMA_FROM_DEVICE:
1230                 vm_srb->data_in = READ_TYPE;
1231                 break;
1232         default:
1233                 vm_srb->data_in = UNKNOWN_TYPE;
1234                 break;
1235         }
1236
1237         request->on_io_completion = storvsc_command_completion;
1238         request->context = cmd_request;/* scmnd; */
1239
1240         vm_srb->port_number = host_dev->port;
1241         vm_srb->path_id = scmnd->device->channel;
1242         vm_srb->target_id = scmnd->device->id;
1243         vm_srb->lun = scmnd->device->lun;
1244
1245         vm_srb->cdb_length = scmnd->cmd_len;
1246
1247         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1248
1249         request->sense_buffer = scmnd->sense_buffer;
1250
1251
1252         request->data_buffer.len = scsi_bufflen(scmnd);
1253         if (scsi_sg_count(scmnd)) {
1254                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1255                 sg_count = scsi_sg_count(scmnd);
1256
1257                 /* check if we need to bounce the sgl */
1258                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1259                         cmd_request->bounce_sgl =
1260                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1261                                                      scsi_bufflen(scmnd));
1262                         if (!cmd_request->bounce_sgl) {
1263                                 scmnd->host_scribble = NULL;
1264                                 mempool_free(cmd_request,
1265                                                 host_dev->request_mempool);
1266
1267                                 return SCSI_MLQUEUE_HOST_BUSY;
1268                         }
1269
1270                         cmd_request->bounce_sgl_count =
1271                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1272                                         PAGE_SHIFT;
1273
1274                         if (vm_srb->data_in == WRITE_TYPE)
1275                                 copy_to_bounce_buffer(sgl,
1276                                         cmd_request->bounce_sgl,
1277                                         scsi_sg_count(scmnd));
1278
1279                         sgl = cmd_request->bounce_sgl;
1280                         sg_count = cmd_request->bounce_sgl_count;
1281                 }
1282
1283                 request->data_buffer.offset = sgl[0].offset;
1284
1285                 for (i = 0; i < sg_count; i++)
1286                         request->data_buffer.pfn_array[i] =
1287                                 page_to_pfn(sg_page((&sgl[i])));
1288
1289         } else if (scsi_sglist(scmnd)) {
1290                 request->data_buffer.offset =
1291                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1292                 request->data_buffer.pfn_array[0] =
1293                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1294         }
1295
1296 retry_request:
1297         /* Invokes the vsc to start an IO */
1298         ret = storvsc_do_io(dev, &cmd_request->request);
1299
1300         if (ret == -EAGAIN) {
1301                 /* no more space */
1302
1303                 if (cmd_request->bounce_sgl_count)
1304                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1305                                         cmd_request->bounce_sgl_count);
1306
1307                 mempool_free(cmd_request, host_dev->request_mempool);
1308
1309                 scmnd->host_scribble = NULL;
1310
1311                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1312         }
1313
1314         return ret;
1315 }
1316
1317 /* Scsi driver */
1318 static struct scsi_host_template scsi_driver = {
1319         .module =               THIS_MODULE,
1320         .name =                 "storvsc_host_t",
1321         .bios_param =           storvsc_get_chs,
1322         .queuecommand =         storvsc_queuecommand,
1323         .eh_host_reset_handler =        storvsc_host_reset_handler,
1324         .slave_alloc =          storvsc_device_alloc,
1325         .slave_configure =      storvsc_device_configure,
1326         .cmd_per_lun =          1,
1327         /* 64 max_queue * 1 target */
1328         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1329         .this_id =              -1,
1330         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1331         /* currently 32 */
1332         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1333         /*
1334          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
1335          * into 1 sg element. If set, we must limit the max_segment_size to
1336          * PAGE_SIZE, otherwise we may get 1 sg element that represents
1337          * multiple
1338          */
1339         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
1340         .use_clustering =       ENABLE_CLUSTERING,
1341         /* Make sure we dont get a sg segment crosses a page boundary */
1342         .dma_boundary =         PAGE_SIZE-1,
1343 };
1344
1345 enum {
1346         SCSI_GUID,
1347         IDE_GUID,
1348 };
1349
1350 static const struct hv_vmbus_device_id id_table[] = {
1351         /* SCSI guid */
1352         { VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
1353                        0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
1354           .driver_data = SCSI_GUID },
1355         /* IDE guid */
1356         { VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
1357                        0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
1358           .driver_data = IDE_GUID },
1359         { },
1360 };
1361
1362 MODULE_DEVICE_TABLE(vmbus, id_table);
1363
1364
1365 /*
1366  * storvsc_probe - Add a new device for this driver
1367  */
1368
1369 static int storvsc_probe(struct hv_device *device,
1370                         const struct hv_vmbus_device_id *dev_id)
1371 {
1372         int ret;
1373         int number = STORVSC_MIN_BUF_NR;
1374         struct Scsi_Host *host;
1375         struct hv_host_device *host_dev;
1376         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1377         int path = 0;
1378         int target = 0;
1379         struct storvsc_device *stor_device;
1380
1381         host = scsi_host_alloc(&scsi_driver,
1382                                sizeof(struct hv_host_device));
1383         if (!host)
1384                 return -ENOMEM;
1385
1386         host_dev = shost_priv(host);
1387         memset(host_dev, 0, sizeof(struct hv_host_device));
1388
1389         host_dev->port = host->host_no;
1390         host_dev->dev = device;
1391
1392         host_dev->request_pool =
1393                                 kmem_cache_create(dev_name(&device->device),
1394                                         sizeof(struct storvsc_cmd_request), 0,
1395                                         SLAB_HWCACHE_ALIGN, NULL);
1396
1397         if (!host_dev->request_pool) {
1398                 scsi_host_put(host);
1399                 return -ENOMEM;
1400         }
1401
1402         host_dev->request_mempool = mempool_create(number, mempool_alloc_slab,
1403                                                 mempool_free_slab,
1404                                                 host_dev->request_pool);
1405
1406         if (!host_dev->request_mempool) {
1407                 ret = -ENOMEM;
1408                 goto err_out0;
1409         }
1410
1411         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1412         if (!stor_device) {
1413                 ret = -ENOMEM;
1414                 goto err_out1;
1415         }
1416
1417         stor_device->destroy = false;
1418         init_waitqueue_head(&stor_device->waiting_to_drain);
1419         stor_device->device = device;
1420         stor_device->host = host;
1421         hv_set_drvdata(device, stor_device);
1422
1423         stor_device->port_number = host->host_no;
1424         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1425         if (ret)
1426                 goto err_out2;
1427
1428         if (dev_is_ide)
1429                 storvsc_get_ide_info(device, &target, &path);
1430
1431         host_dev->path = stor_device->path_id;
1432         host_dev->target = stor_device->target_id;
1433
1434         /* max # of devices per target */
1435         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1436         /* max # of targets per channel */
1437         host->max_id = STORVSC_MAX_TARGETS;
1438         /* max # of channels */
1439         host->max_channel = STORVSC_MAX_CHANNELS - 1;
1440         /* max cmd length */
1441         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1442
1443         /* Register the HBA and start the scsi bus scan */
1444         ret = scsi_add_host(host, &device->device);
1445         if (ret != 0)
1446                 goto err_out3;
1447
1448         if (!dev_is_ide) {
1449                 scsi_scan_host(host);
1450                 return 0;
1451         }
1452         ret = scsi_add_device(host, 0, target, 0);
1453         if (ret) {
1454                 scsi_remove_host(host);
1455                 goto err_out3;
1456         }
1457         return 0;
1458
1459 err_out3:
1460         /*
1461          * Once we have connected with the host, we would need to
1462          * to invoke storvsc_dev_remove() to rollback this state and
1463          * this call also frees up the stor_device; hence the jump around
1464          * err_out2 label.
1465          */
1466         storvsc_dev_remove(device);
1467         goto err_out1;
1468
1469 err_out2:
1470         kfree(stor_device);
1471
1472 err_out1:
1473         mempool_destroy(host_dev->request_mempool);
1474
1475 err_out0:
1476         kmem_cache_destroy(host_dev->request_pool);
1477         scsi_host_put(host);
1478         return ret;
1479 }
1480
1481 /* The one and only one */
1482
1483 static struct hv_driver storvsc_drv = {
1484         .name = KBUILD_MODNAME,
1485         .id_table = id_table,
1486         .probe = storvsc_probe,
1487         .remove = storvsc_remove,
1488 };
1489
1490 static int __init storvsc_drv_init(void)
1491 {
1492         u32 max_outstanding_req_per_channel;
1493
1494         /*
1495          * Divide the ring buffer data size (which is 1 page less
1496          * than the ring buffer size since that page is reserved for
1497          * the ring buffer indices) by the max request size (which is
1498          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1499          */
1500         max_outstanding_req_per_channel =
1501                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1502                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1503                 sizeof(struct vstor_packet) + sizeof(u64),
1504                 sizeof(u64)));
1505
1506         if (max_outstanding_req_per_channel <
1507             STORVSC_MAX_IO_REQUESTS)
1508                 return -EINVAL;
1509
1510         return vmbus_driver_register(&storvsc_drv);
1511 }
1512
1513 static void __exit storvsc_drv_exit(void)
1514 {
1515         vmbus_driver_unregister(&storvsc_drv);
1516 }
1517
1518 MODULE_LICENSE("GPL");
1519 MODULE_VERSION(HV_DRV_VERSION);
1520 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1521 module_init(storvsc_drv_init);
1522 module_exit(storvsc_drv_exit);