Pileus Git - ~andy/linux/blob - 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
 236 struct hv_storvsc_request;
 237
 238 /* Matches Windows-end */
 239 enum storvsc_request_type {
 240         WRITE_TYPE,
 241         READ_TYPE,
 242         UNKNOWN_TYPE,
 243 };
 244
 245
 246 struct hv_storvsc_request {
 247         struct hv_storvsc_request *request;
 248         struct hv_device *device;
 249
 250         /* Synchronize the request/response if needed */
 251         struct completion wait_event;
 252
 253         unsigned char *sense_buffer;
 254         void *context;
 255         void (*on_io_completion)(struct hv_storvsc_request *request);
 256         struct hv_multipage_buffer data_buffer;
 257
 258         struct vstor_packet vstor_packet;
 259 };
 260
 261
 262 struct storvsc_device_info {
 263         u32 ring_buffer_size;
 264         unsigned int port_number;
 265         unsigned char path_id;
 266         unsigned char target_id;
 267 };
 268
 269
 270 /* A storvsc device is a device object that contains a vmbus channel */
 271 struct storvsc_device {
 272         struct hv_device *device;
 273
 274         bool     destroy;
 275         bool     drain_notify;
 276         atomic_t num_outstanding_req;
 277
 278         wait_queue_head_t waiting_to_drain;
 279
 280         /*
 281          * Each unique Port/Path/Target represents 1 channel ie scsi
 282          * controller. In reality, the pathid, targetid is always 0
 283          * and the port is set by us
 284          */
 285         unsigned int port_number;
 286         unsigned char path_id;
 287         unsigned char target_id;
 288
 289         /* Used for vsc/vsp channel reset process */
 290         struct hv_storvsc_request init_request;
 291         struct hv_storvsc_request reset_request;
 292 };
 293
 294 struct hv_host_device {
 295         struct hv_device *dev;
 296         struct kmem_cache *request_pool;
 297         unsigned int port;
 298         unsigned char path;
 299         unsigned char target;
 300 };
 301
 302 struct storvsc_cmd_request {
 303         struct list_head entry;
 304         struct scsi_cmnd *cmd;
 305
 306         unsigned int bounce_sgl_count;
 307         struct scatterlist *bounce_sgl;
 308
 309         struct hv_storvsc_request request;
 310 };
 311
 312 static inline struct storvsc_device *get_out_stor_device(
 313                                         struct hv_device *device)
 314 {
 315         struct storvsc_device *stor_device;
 316
 317         stor_device = (struct storvsc_device *)device->ext;
 318
 319         if (stor_device && stor_device->destroy)
 320                 stor_device = NULL;
 321
 322         return stor_device;
 323 }
 324
 325
 326 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 327 {
 328         dev->drain_notify = true;
 329         wait_event(dev->waiting_to_drain,
 330                    atomic_read(&dev->num_outstanding_req) == 0);
 331         dev->drain_notify = false;
 332 }
 333
 334 static inline struct storvsc_device *alloc_stor_device(struct hv_device *device)
 335 {
 336         struct storvsc_device *stor_device;
 337
 338         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
 339         if (!stor_device)
 340                 return NULL;
 341
 342         stor_device->destroy = false;
 343         init_waitqueue_head(&stor_device->waiting_to_drain);
 344         stor_device->device = device;
 345         device->ext = stor_device;
 346
 347         return stor_device;
 348 }
 349
 350
 351 static inline struct storvsc_device *get_in_stor_device(
 352                                         struct hv_device *device)
 353 {
 354         struct storvsc_device *stor_device;
 355
 356         stor_device = (struct storvsc_device *)device->ext;
 357
 358         if (!stor_device)
 359                 goto get_in_err;
 360
 361         /*
 362          * If the device is being destroyed; allow incoming
 363          * traffic only to cleanup outstanding requests.
 364          */
 365
 366         if (stor_device->destroy  &&
 367                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 368                 stor_device = NULL;
 369
 370 get_in_err:
 371         return stor_device;
 372
 373 }
 374
 375 static int storvsc_channel_init(struct hv_device *device)
 376 {
 377         struct storvsc_device *stor_device;
 378         struct hv_storvsc_request *request;
 379         struct vstor_packet *vstor_packet;
 380         int ret, t;
 381
 382         stor_device = get_out_stor_device(device);
 383         if (!stor_device)
 384                 return -ENODEV;
 385
 386         request = &stor_device->init_request;
 387         vstor_packet = &request->vstor_packet;
 388
 389         /*
 390          * Now, initiate the vsc/vsp initialization protocol on the open
 391          * channel
 392          */
 393         memset(request, 0, sizeof(struct hv_storvsc_request));
 394         init_completion(&request->wait_event);
 395         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 396         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 397
 398         ret = vmbus_sendpacket(device->channel, vstor_packet,
 399                                sizeof(struct vstor_packet),
 400                                (unsigned long)request,
 401                                VM_PKT_DATA_INBAND,
 402                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 403         if (ret != 0)
 404                 goto cleanup;
 405
 406         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 407         if (t == 0) {
 408                 ret = -ETIMEDOUT;
 409                 goto cleanup;
 410         }
 411
 412         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 413             vstor_packet->status != 0)
 414                 goto cleanup;
 415
 416
 417         /* reuse the packet for version range supported */
 418         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 419         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 420         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 421
 422         vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
 423         FILL_VMSTOR_REVISION(vstor_packet->version.revision);
 424
 425         ret = vmbus_sendpacket(device->channel, vstor_packet,
 426                                sizeof(struct vstor_packet),
 427                                (unsigned long)request,
 428                                VM_PKT_DATA_INBAND,
 429                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 430         if (ret != 0)
 431                 goto cleanup;
 432
 433         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 434         if (t == 0) {
 435                 ret = -ETIMEDOUT;
 436                 goto cleanup;
 437         }
 438
 439         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 440             vstor_packet->status != 0)
 441                 goto cleanup;
 442
 443
 444         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 445         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 446         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 447         vstor_packet->storage_channel_properties.port_number =
 448                                         stor_device->port_number;
 449
 450         ret = vmbus_sendpacket(device->channel, vstor_packet,
 451                                sizeof(struct vstor_packet),
 452                                (unsigned long)request,
 453                                VM_PKT_DATA_INBAND,
 454                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 455
 456         if (ret != 0)
 457                 goto cleanup;
 458
 459         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 460         if (t == 0) {
 461                 ret = -ETIMEDOUT;
 462                 goto cleanup;
 463         }
 464
 465         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 466             vstor_packet->status != 0)
 467                 goto cleanup;
 468
 469         stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
 470         stor_device->target_id
 471                 = vstor_packet->storage_channel_properties.target_id;
 472
 473         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 474         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 475         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 476
 477         ret = vmbus_sendpacket(device->channel, vstor_packet,
 478                                sizeof(struct vstor_packet),
 479                                (unsigned long)request,
 480                                VM_PKT_DATA_INBAND,
 481                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 482
 483         if (ret != 0)
 484                 goto cleanup;
 485
 486         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 487         if (t == 0) {
 488                 ret = -ETIMEDOUT;
 489                 goto cleanup;
 490         }
 491
 492         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 493             vstor_packet->status != 0)
 494                 goto cleanup;
 495
 496
 497 cleanup:
 498         return ret;
 499 }
 500
 501 static void storvsc_on_io_completion(struct hv_device *device,
 502                                   struct vstor_packet *vstor_packet,
 503                                   struct hv_storvsc_request *request)
 504 {
 505         struct storvsc_device *stor_device;
 506         struct vstor_packet *stor_pkt;
 507
 508         stor_device = (struct storvsc_device *)device->ext;
 509
 510         stor_pkt = &request->vstor_packet;
 511
 512         /*
 513          * The current SCSI handling on the host side does
 514          * not correctly handle:
 515          * INQUIRY command with page code parameter set to 0x80
 516          * MODE_SENSE command with cmd[2] == 0x1c
 517          *
 518          * Setup srb and scsi status so this won't be fatal.
 519          * We do this so we can distinguish truly fatal failues
 520          * (srb status == 0x4) and off-line the device in that case.
 521          */
 522
 523         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
 524                 (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
 525                 vstor_packet->vm_srb.scsi_status = 0;
 526                 vstor_packet->vm_srb.srb_status = 0x1;
 527         }
 528
 529
 530         /* Copy over the status...etc */
 531         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 532         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 533         stor_pkt->vm_srb.sense_info_length =
 534         vstor_packet->vm_srb.sense_info_length;
 535
 536         if (vstor_packet->vm_srb.scsi_status != 0 ||
 537                 vstor_packet->vm_srb.srb_status != 1){
 538                 DPRINT_WARN(STORVSC,
 539                             "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 540                             stor_pkt->vm_srb.cdb[0],
 541                             vstor_packet->vm_srb.scsi_status,
 542                             vstor_packet->vm_srb.srb_status);
 543         }
 544
 545         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 546                 /* CHECK_CONDITION */
 547                 if (vstor_packet->vm_srb.srb_status & 0x80) {
 548                         /* autosense data available */
 549                         DPRINT_WARN(STORVSC, "storvsc pkt %p autosense data "
 550                                     "valid - len %d\n", request,
 551                                     vstor_packet->vm_srb.sense_info_length);
 552
 553                         memcpy(request->sense_buffer,
 554                                vstor_packet->vm_srb.sense_data,
 555                                vstor_packet->vm_srb.sense_info_length);
 556
 557                 }
 558         }
 559
 560         stor_pkt->vm_srb.data_transfer_length =
 561         vstor_packet->vm_srb.data_transfer_length;
 562
 563         request->on_io_completion(request);
 564
 565         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 566                 stor_device->drain_notify)
 567                 wake_up(&stor_device->waiting_to_drain);
 568
 569
 570 }
 571
 572 static void storvsc_on_receive(struct hv_device *device,
 573                              struct vstor_packet *vstor_packet,
 574                              struct hv_storvsc_request *request)
 575 {
 576         switch (vstor_packet->operation) {
 577         case VSTOR_OPERATION_COMPLETE_IO:
 578                 storvsc_on_io_completion(device, vstor_packet, request);
 579                 break;
 580         case VSTOR_OPERATION_REMOVE_DEVICE:
 581
 582         default:
 583                 break;
 584         }
 585 }
 586
 587 static void storvsc_on_channel_callback(void *context)
 588 {
 589         struct hv_device *device = (struct hv_device *)context;
 590         struct storvsc_device *stor_device;
 591         u32 bytes_recvd;
 592         u64 request_id;
 593         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 594         struct hv_storvsc_request *request;
 595         int ret;
 596
 597
 598         stor_device = get_in_stor_device(device);
 599         if (!stor_device)
 600                 return;
 601
 602         do {
 603                 ret = vmbus_recvpacket(device->channel, packet,
 604                                        ALIGN(sizeof(struct vstor_packet), 8),
 605                                        &bytes_recvd, &request_id);
 606                 if (ret == 0 && bytes_recvd > 0) {
 607
 608                         request = (struct hv_storvsc_request *)
 609                                         (unsigned long)request_id;
 610
 611                         if ((request == &stor_device->init_request) ||
 612                             (request == &stor_device->reset_request)) {
 613
 614                                 memcpy(&request->vstor_packet, packet,
 615                                        sizeof(struct vstor_packet));
 616                                 complete(&request->wait_event);
 617                         } else {
 618                                 storvsc_on_receive(device,
 619                                                 (struct vstor_packet *)packet,
 620                                                 request);
 621                         }
 622                 } else {
 623                         break;
 624                 }
 625         } while (1);
 626
 627         return;
 628 }
 629
 630 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 631 {
 632         struct vmstorage_channel_properties props;
 633         int ret;
 634
 635         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 636
 637         /* Open the channel */
 638         ret = vmbus_open(device->channel,
 639                          ring_size,
 640                          ring_size,
 641                          (void *)&props,
 642                          sizeof(struct vmstorage_channel_properties),
 643                          storvsc_on_channel_callback, device);
 644
 645         if (ret != 0)
 646                 return ret;
 647
 648         ret = storvsc_channel_init(device);
 649
 650         return ret;
 651 }
 652
 653 static int storvsc_dev_add(struct hv_device *device,
 654                                         void *additional_info)
 655 {
 656         struct storvsc_device *stor_device;
 657         struct storvsc_device_info *device_info;
 658         int ret = 0;
 659
 660         device_info = (struct storvsc_device_info *)additional_info;
 661         stor_device = alloc_stor_device(device);
 662         if (!stor_device)
 663                 return -ENOMEM;
 664
 665         /* Save the channel properties to our storvsc channel */
 666
 667         /*
 668          * If we support more than 1 scsi channel, we need to set the
 669          * port number here to the scsi channel but how do we get the
 670          * scsi channel prior to the bus scan.
 671          *
 672          * The host does not support this.
 673          */
 674
 675         stor_device->port_number = device_info->port_number;
 676         /* Send it back up */
 677         ret = storvsc_connect_to_vsp(device, device_info->ring_buffer_size);
 678         if (ret) {
 679                 kfree(stor_device);
 680                 return ret;
 681         }
 682         device_info->path_id = stor_device->path_id;
 683         device_info->target_id = stor_device->target_id;
 684
 685         return ret;
 686 }
 687
 688 static int storvsc_dev_remove(struct hv_device *device)
 689 {
 690         struct storvsc_device *stor_device;
 691         unsigned long flags;
 692
 693         stor_device = (struct storvsc_device *)device->ext;
 694
 695         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 696         stor_device->destroy = true;
 697         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 698
 699         /*
 700          * At this point, all outbound traffic should be disable. We
 701          * only allow inbound traffic (responses) to proceed so that
 702          * outstanding requests can be completed.
 703          */
 704
 705         storvsc_wait_to_drain(stor_device);
 706
 707         /*
 708          * Since we have already drained, we don't need to busy wait
 709          * as was done in final_release_stor_device()
 710          * Note that we cannot set the ext pointer to NULL until
 711          * we have drained - to drain the outgoing packets, we need to
 712          * allow incoming packets.
 713          */
 714         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 715         device->ext = NULL;
 716         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 717
 718         /* Close the channel */
 719         vmbus_close(device->channel);
 720
 721         kfree(stor_device);
 722         return 0;
 723 }
 724
 725 static int storvsc_do_io(struct hv_device *device,
 726                               struct hv_storvsc_request *request)
 727 {
 728         struct storvsc_device *stor_device;
 729         struct vstor_packet *vstor_packet;
 730         int ret = 0;
 731
 732         vstor_packet = &request->vstor_packet;
 733         stor_device = get_out_stor_device(device);
 734
 735         if (!stor_device)
 736                 return -ENODEV;
 737
 738
 739         request->device  = device;
 740
 741
 742         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
 743
 744         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
 745
 746
 747         vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
 748
 749
 750         vstor_packet->vm_srb.data_transfer_length =
 751         request->data_buffer.len;
 752
 753         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 754
 755         if (request->data_buffer.len) {
 756                 ret = vmbus_sendpacket_multipagebuffer(device->channel,
 757                                 &request->data_buffer,
 758                                 vstor_packet,
 759                                 sizeof(struct vstor_packet),
 760                                 (unsigned long)request);
 761         } else {
 762                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 763                                sizeof(struct vstor_packet),
 764                                (unsigned long)request,
 765                                VM_PKT_DATA_INBAND,
 766                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 767         }
 768
 769         if (ret != 0)
 770                 return ret;
 771
 772         atomic_inc(&stor_device->num_outstanding_req);
 773
 774         return ret;
 775 }
 776
 777 static void storvsc_get_ide_info(struct hv_device *dev, int *target, int *path)
 778 {
 779         *target =
 780                 dev->dev_instance.b[5] << 8 | dev->dev_instance.b[4];
 781
 782         *path =
 783                 dev->dev_instance.b[3] << 24 |
 784                 dev->dev_instance.b[2] << 16 |
 785                 dev->dev_instance.b[1] << 8  | dev->dev_instance.b[0];
 786 }
 787
 788
 789 static int storvsc_device_alloc(struct scsi_device *sdevice)
 790 {
 791         /*
 792          * This enables luns to be located sparsely. Otherwise, we may not
 793          * discovered them.
 794          */
 795         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 796         return 0;
 797 }
 798
 799 static int storvsc_merge_bvec(struct request_queue *q,
 800                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 801 {
 802         /* checking done by caller. */
 803         return bvec->bv_len;
 804 }
 805
 806 static int storvsc_device_configure(struct scsi_device *sdevice)
 807 {
 808         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 809                                 STORVSC_MAX_IO_REQUESTS);
 810
 811         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 812
 813         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 814
 815         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 816
 817         return 0;
 818 }
 819
 820 static void destroy_bounce_buffer(struct scatterlist *sgl,
 821                                   unsigned int sg_count)
 822 {
 823         int i;
 824         struct page *page_buf;
 825
 826         for (i = 0; i < sg_count; i++) {
 827                 page_buf = sg_page((&sgl[i]));
 828                 if (page_buf != NULL)
 829                         __free_page(page_buf);
 830         }
 831
 832         kfree(sgl);
 833 }
 834
 835 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 836 {
 837         int i;
 838
 839         /* No need to check */
 840         if (sg_count < 2)
 841                 return -1;
 842
 843         /* We have at least 2 sg entries */
 844         for (i = 0; i < sg_count; i++) {
 845                 if (i == 0) {
 846                         /* make sure 1st one does not have hole */
 847                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 848                                 return i;
 849                 } else if (i == sg_count - 1) {
 850                         /* make sure last one does not have hole */
 851                         if (sgl[i].offset != 0)
 852                                 return i;
 853                 } else {
 854                         /* make sure no hole in the middle */
 855                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 856                                 return i;
 857                 }
 858         }
 859         return -1;
 860 }
 861
 862 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 863                                                 unsigned int sg_count,
 864                                                 unsigned int len)
 865 {
 866         int i;
 867         int num_pages;
 868         struct scatterlist *bounce_sgl;
 869         struct page *page_buf;
 870
 871         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 872
 873         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 874         if (!bounce_sgl)
 875                 return NULL;
 876
 877         for (i = 0; i < num_pages; i++) {
 878                 page_buf = alloc_page(GFP_ATOMIC);
 879                 if (!page_buf)
 880                         goto cleanup;
 881                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 882         }
 883
 884         return bounce_sgl;
 885
 886 cleanup:
 887         destroy_bounce_buffer(bounce_sgl, num_pages);
 888         return NULL;
 889 }
 890
 891
 892 /* Assume the original sgl has enough room */
 893 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 894                                             struct scatterlist *bounce_sgl,
 895                                             unsigned int orig_sgl_count)
 896 {
 897         int i;
 898         int j = 0;
 899         unsigned long src, dest;
 900         unsigned int srclen, destlen, copylen;
 901         unsigned int total_copied = 0;
 902         unsigned long bounce_addr = 0;
 903         unsigned long dest_addr = 0;
 904         unsigned long flags;
 905
 906         local_irq_save(flags);
 907
 908         for (i = 0; i < orig_sgl_count; i++) {
 909                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 910                                         KM_IRQ0) + orig_sgl[i].offset;
 911                 dest = dest_addr;
 912                 destlen = orig_sgl[i].length;
 913
 914                 if (bounce_addr == 0)
 915                         bounce_addr =
 916                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 917                                                         KM_IRQ0);
 918
 919                 while (destlen) {
 920                         src = bounce_addr + bounce_sgl[j].offset;
 921                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 922
 923                         copylen = min(srclen, destlen);
 924                         memcpy((void *)dest, (void *)src, copylen);
 925
 926                         total_copied += copylen;
 927                         bounce_sgl[j].offset += copylen;
 928                         destlen -= copylen;
 929                         dest += copylen;
 930
 931                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 932                                 /* full */
 933                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 934                                 j++;
 935
 936                                 /* if we need to use another bounce buffer */
 937                                 if (destlen || i != orig_sgl_count - 1)
 938                                         bounce_addr =
 939                                         (unsigned long)kmap_atomic(
 940                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 941                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 942                                 /* unmap the last bounce that is < PAGE_SIZE */
 943                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 944                         }
 945                 }
 946
 947                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 948                               KM_IRQ0);
 949         }
 950
 951         local_irq_restore(flags);
 952
 953         return total_copied;
 954 }
 955
 956
 957 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 958 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 959                                           struct scatterlist *bounce_sgl,
 960                                           unsigned int orig_sgl_count)
 961 {
 962         int i;
 963         int j = 0;
 964         unsigned long src, dest;
 965         unsigned int srclen, destlen, copylen;
 966         unsigned int total_copied = 0;
 967         unsigned long bounce_addr = 0;
 968         unsigned long src_addr = 0;
 969         unsigned long flags;
 970
 971         local_irq_save(flags);
 972
 973         for (i = 0; i < orig_sgl_count; i++) {
 974                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 975                                 KM_IRQ0) + orig_sgl[i].offset;
 976                 src = src_addr;
 977                 srclen = orig_sgl[i].length;
 978
 979                 if (bounce_addr == 0)
 980                         bounce_addr =
 981                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 982                                                 KM_IRQ0);
 983
 984                 while (srclen) {
 985                         /* assume bounce offset always == 0 */
 986                         dest = bounce_addr + bounce_sgl[j].length;
 987                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 988
 989                         copylen = min(srclen, destlen);
 990                         memcpy((void *)dest, (void *)src, copylen);
 991
 992                         total_copied += copylen;
 993                         bounce_sgl[j].length += copylen;
 994                         srclen -= copylen;
 995                         src += copylen;
 996
 997                         if (bounce_sgl[j].length == PAGE_SIZE) {
 998                                 /* full..move to next entry */
 999                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
1000                                 j++;
1001
1002                                 /* if we need to use another bounce buffer */
1003                                 if (srclen || i != orig_sgl_count - 1)
1004                                         bounce_addr =
1005                                         (unsigned long)kmap_atomic(
1006                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
1007
1008                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
1009                                 /* unmap the last bounce that is < PAGE_SIZE */
1010                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
1011                         }
1012                 }
1013
1014                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
1015         }
1016
1017         local_irq_restore(flags);
1018
1019         return total_copied;
1020 }
1021
1022
1023 static int storvsc_remove(struct hv_device *dev)
1024 {
1025         struct Scsi_Host *host = dev_get_drvdata(&dev->device);
1026         struct hv_host_device *host_dev =
1027                         (struct hv_host_device *)host->hostdata;
1028
1029         scsi_remove_host(host);
1030
1031         scsi_host_put(host);
1032
1033         storvsc_dev_remove(dev);
1034         if (host_dev->request_pool) {
1035                 kmem_cache_destroy(host_dev->request_pool);
1036                 host_dev->request_pool = NULL;
1037         }
1038         return 0;
1039 }
1040
1041
1042 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1043                            sector_t capacity, int *info)
1044 {
1045         sector_t nsect = capacity;
1046         sector_t cylinders = nsect;
1047         int heads, sectors_pt;
1048
1049         /*
1050          * We are making up these values; let us keep it simple.
1051          */
1052         heads = 0xff;
1053         sectors_pt = 0x3f;      /* Sectors per track */
1054         sector_div(cylinders, heads * sectors_pt);
1055         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1056                 cylinders = 0xffff;
1057
1058         info[0] = heads;
1059         info[1] = sectors_pt;
1060         info[2] = (int)cylinders;
1061
1062         return 0;
1063 }
1064
1065 static int storvsc_host_reset(struct hv_device *device)
1066 {
1067         struct storvsc_device *stor_device;
1068         struct hv_storvsc_request *request;
1069         struct vstor_packet *vstor_packet;
1070         int ret, t;
1071
1072
1073         stor_device = get_out_stor_device(device);
1074         if (!stor_device)
1075                 return -ENODEV;
1076
1077         request = &stor_device->reset_request;
1078         vstor_packet = &request->vstor_packet;
1079
1080         init_completion(&request->wait_event);
1081
1082         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1083         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1084         vstor_packet->vm_srb.path_id = stor_device->path_id;
1085
1086         ret = vmbus_sendpacket(device->channel, vstor_packet,
1087                                sizeof(struct vstor_packet),
1088                                (unsigned long)&stor_device->reset_request,
1089                                VM_PKT_DATA_INBAND,
1090                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1091         if (ret != 0)
1092                 goto cleanup;
1093
1094         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1095         if (t == 0) {
1096                 ret = -ETIMEDOUT;
1097                 goto cleanup;
1098         }
1099
1100
1101         /*
1102          * At this point, all outstanding requests in the adapter
1103          * should have been flushed out and return to us
1104          */
1105
1106 cleanup:
1107         return ret;
1108 }
1109
1110
1111 /*
1112  * storvsc_host_reset_handler - Reset the scsi HBA
1113  */
1114 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1115 {
1116         int ret;
1117         struct hv_host_device *host_dev =
1118                 (struct hv_host_device *)scmnd->device->host->hostdata;
1119         struct hv_device *dev = host_dev->dev;
1120
1121         ret = storvsc_host_reset(dev);
1122         if (ret != 0)
1123                 return ret;
1124
1125         return ret;
1126 }
1127
1128
1129 /*
1130  * storvsc_command_completion - Command completion processing
1131  */
1132 static void storvsc_command_completion(struct hv_storvsc_request *request)
1133 {
1134         struct storvsc_cmd_request *cmd_request =
1135                 (struct storvsc_cmd_request *)request->context;
1136         struct scsi_cmnd *scmnd = cmd_request->cmd;
1137         struct hv_host_device *host_dev =
1138                 (struct hv_host_device *)scmnd->device->host->hostdata;
1139         void (*scsi_done_fn)(struct scsi_cmnd *);
1140         struct scsi_sense_hdr sense_hdr;
1141         struct vmscsi_request *vm_srb;
1142
1143         vm_srb = &request->vstor_packet.vm_srb;
1144         if (cmd_request->bounce_sgl_count) {
1145                 if (vm_srb->data_in == READ_TYPE) {
1146                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1147                                         cmd_request->bounce_sgl,
1148                                         scsi_sg_count(scmnd));
1149                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1150                                         cmd_request->bounce_sgl_count);
1151                 }
1152         }
1153
1154         /*
1155          * If there is an error; offline the device since all
1156          * error recovery strategies would have already been
1157          * deployed on the host side.
1158          */
1159         if (vm_srb->srb_status == 0x4)
1160                 scmnd->result = DID_TARGET_FAILURE << 16;
1161         else
1162                 scmnd->result = vm_srb->scsi_status;
1163
1164         if (scmnd->result) {
1165                 if (scsi_normalize_sense(scmnd->sense_buffer,
1166                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1167                         scsi_print_sense_hdr("storvsc", &sense_hdr);
1168         }
1169
1170         scsi_set_resid(scmnd,
1171                 request->data_buffer.len -
1172                 vm_srb->data_transfer_length);
1173
1174         scsi_done_fn = scmnd->scsi_done;
1175
1176         scmnd->host_scribble = NULL;
1177         scmnd->scsi_done = NULL;
1178
1179         scsi_done_fn(scmnd);
1180
1181         kmem_cache_free(host_dev->request_pool, cmd_request);
1182 }
1183
1184
1185 /*
1186  * storvsc_queuecommand - Initiate command processing
1187  */
1188 static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
1189                                 void (*done)(struct scsi_cmnd *))
1190 {
1191         int ret;
1192         struct hv_host_device *host_dev =
1193                 (struct hv_host_device *)scmnd->device->host->hostdata;
1194         struct hv_device *dev = host_dev->dev;
1195         struct hv_storvsc_request *request;
1196         struct storvsc_cmd_request *cmd_request;
1197         unsigned int request_size = 0;
1198         int i;
1199         struct scatterlist *sgl;
1200         unsigned int sg_count = 0;
1201         struct vmscsi_request *vm_srb;
1202
1203
1204         /* If retrying, no need to prep the cmd */
1205         if (scmnd->host_scribble) {
1206
1207                 cmd_request =
1208                         (struct storvsc_cmd_request *)scmnd->host_scribble;
1209
1210                 goto retry_request;
1211         }
1212
1213         scmnd->scsi_done = done;
1214
1215         request_size = sizeof(struct storvsc_cmd_request);
1216
1217         cmd_request = kmem_cache_zalloc(host_dev->request_pool,
1218                                        GFP_ATOMIC);
1219         if (!cmd_request) {
1220                 scmnd->scsi_done = NULL;
1221                 return SCSI_MLQUEUE_DEVICE_BUSY;
1222         }
1223
1224         /* Setup the cmd request */
1225         cmd_request->bounce_sgl_count = 0;
1226         cmd_request->bounce_sgl = NULL;
1227         cmd_request->cmd = scmnd;
1228
1229         scmnd->host_scribble = (unsigned char *)cmd_request;
1230
1231         request = &cmd_request->request;
1232         vm_srb = &request->vstor_packet.vm_srb;
1233
1234
1235         /* Build the SRB */
1236         switch (scmnd->sc_data_direction) {
1237         case DMA_TO_DEVICE:
1238                 vm_srb->data_in = WRITE_TYPE;
1239                 break;
1240         case DMA_FROM_DEVICE:
1241                 vm_srb->data_in = READ_TYPE;
1242                 break;
1243         default:
1244                 vm_srb->data_in = UNKNOWN_TYPE;
1245                 break;
1246         }
1247
1248         request->on_io_completion = storvsc_command_completion;
1249         request->context = cmd_request;/* scmnd; */
1250
1251         vm_srb->port_number = host_dev->port;
1252         vm_srb->path_id = scmnd->device->channel;
1253         vm_srb->target_id = scmnd->device->id;
1254         vm_srb->lun = scmnd->device->lun;
1255
1256         vm_srb->cdb_length = scmnd->cmd_len;
1257
1258         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1259
1260         request->sense_buffer = scmnd->sense_buffer;
1261
1262
1263         request->data_buffer.len = scsi_bufflen(scmnd);
1264         if (scsi_sg_count(scmnd)) {
1265                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1266                 sg_count = scsi_sg_count(scmnd);
1267
1268                 /* check if we need to bounce the sgl */
1269                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1270                         cmd_request->bounce_sgl =
1271                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1272                                                      scsi_bufflen(scmnd));
1273                         if (!cmd_request->bounce_sgl) {
1274                                 scmnd->scsi_done = NULL;
1275                                 scmnd->host_scribble = NULL;
1276                                 kmem_cache_free(host_dev->request_pool,
1277                                                 cmd_request);
1278
1279                                 return SCSI_MLQUEUE_HOST_BUSY;
1280                         }
1281
1282                         cmd_request->bounce_sgl_count =
1283                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1284                                         PAGE_SHIFT;
1285
1286                         if (vm_srb->data_in == WRITE_TYPE)
1287                                 copy_to_bounce_buffer(sgl,
1288                                         cmd_request->bounce_sgl,
1289                                         scsi_sg_count(scmnd));
1290
1291                         sgl = cmd_request->bounce_sgl;
1292                         sg_count = cmd_request->bounce_sgl_count;
1293                 }
1294
1295                 request->data_buffer.offset = sgl[0].offset;
1296
1297                 for (i = 0; i < sg_count; i++)
1298                         request->data_buffer.pfn_array[i] =
1299                                 page_to_pfn(sg_page((&sgl[i])));
1300
1301         } else if (scsi_sglist(scmnd)) {
1302                 request->data_buffer.offset =
1303                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1304                 request->data_buffer.pfn_array[0] =
1305                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1306         }
1307
1308 retry_request:
1309         /* Invokes the vsc to start an IO */
1310         ret = storvsc_do_io(dev, &cmd_request->request);
1311
1312         if (ret == -EAGAIN) {
1313                 /* no more space */
1314
1315                 if (cmd_request->bounce_sgl_count)
1316                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1317                                         cmd_request->bounce_sgl_count);
1318
1319                 kmem_cache_free(host_dev->request_pool, cmd_request);
1320
1321                 scmnd->scsi_done = NULL;
1322                 scmnd->host_scribble = NULL;
1323
1324                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1325         }
1326
1327         return ret;
1328 }
1329
1330 static DEF_SCSI_QCMD(storvsc_queuecommand)
1331
1332
1333 /* Scsi driver */
1334 static struct scsi_host_template scsi_driver = {
1335         .module =               THIS_MODULE,
1336         .name =                 "storvsc_host_t",
1337         .bios_param =           storvsc_get_chs,
1338         .queuecommand =         storvsc_queuecommand,
1339         .eh_host_reset_handler =        storvsc_host_reset_handler,
1340         .slave_alloc =          storvsc_device_alloc,
1341         .slave_configure =      storvsc_device_configure,
1342         .cmd_per_lun =          1,
1343         /* 64 max_queue * 1 target */
1344         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1345         .this_id =              -1,
1346         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1347         /* currently 32 */
1348         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1349         /*
1350          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
1351          * into 1 sg element. If set, we must limit the max_segment_size to
1352          * PAGE_SIZE, otherwise we may get 1 sg element that represents
1353          * multiple
1354          */
1355         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
1356         .use_clustering =       ENABLE_CLUSTERING,
1357         /* Make sure we dont get a sg segment crosses a page boundary */
1358         .dma_boundary =         PAGE_SIZE-1,
1359 };
1360
1361 /*
1362  * The storvsc_probe function assumes that the IDE guid
1363  * is the second entry.
1364  */
1365 static const struct hv_vmbus_device_id id_table[] = {
1366         /* SCSI guid */
1367         { VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
1368                        0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f) },
1369         /* IDE guid */
1370         { VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
1371                        0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5) },
1372         { },
1373 };
1374
1375 MODULE_DEVICE_TABLE(vmbus, id_table);
1376
1377
1378 /*
1379  * storvsc_probe - Add a new device for this driver
1380  */
1381
1382 static int storvsc_probe(struct hv_device *device)
1383 {
1384         int ret;
1385         struct Scsi_Host *host;
1386         struct hv_host_device *host_dev;
1387         struct storvsc_device_info device_info;
1388         bool dev_is_ide;
1389         int path = 0;
1390         int target = 0;
1391
1392         if (!memcmp(&device->dev_type.b, id_table[1].guid, sizeof(uuid_le)))
1393                 dev_is_ide = true;
1394         else
1395                 dev_is_ide = false;
1396
1397         host = scsi_host_alloc(&scsi_driver,
1398                                sizeof(struct hv_host_device));
1399         if (!host)
1400                 return -ENOMEM;
1401
1402         dev_set_drvdata(&device->device, host);
1403
1404         host_dev = (struct hv_host_device *)host->hostdata;
1405         memset(host_dev, 0, sizeof(struct hv_host_device));
1406
1407         host_dev->port = host->host_no;
1408         host_dev->dev = device;
1409
1410         host_dev->request_pool =
1411                                 kmem_cache_create(dev_name(&device->device),
1412                                         sizeof(struct storvsc_cmd_request), 0,
1413                                         SLAB_HWCACHE_ALIGN, NULL);
1414
1415         if (!host_dev->request_pool) {
1416                 scsi_host_put(host);
1417                 return -ENOMEM;
1418         }
1419
1420         device_info.port_number = host->host_no;
1421         device_info.ring_buffer_size  = storvsc_ringbuffer_size;
1422         /* Call to the vsc driver to add the device */
1423         ret = storvsc_dev_add(device, (void *)&device_info);
1424
1425         if (ret != 0) {
1426                 kmem_cache_destroy(host_dev->request_pool);
1427                 scsi_host_put(host);
1428                 return -ENODEV;
1429         }
1430
1431         if (dev_is_ide)
1432                 storvsc_get_ide_info(device, &target, &path);
1433
1434         host_dev->path = device_info.path_id;
1435         host_dev->target = device_info.target_id;
1436
1437         /* max # of devices per target */
1438         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1439         /* max # of targets per channel */
1440         host->max_id = STORVSC_MAX_TARGETS;
1441         /* max # of channels */
1442         host->max_channel = STORVSC_MAX_CHANNELS - 1;
1443
1444         /* Register the HBA and start the scsi bus scan */
1445         ret = scsi_add_host(host, &device->device);
1446         if (ret != 0)
1447                 goto err_out;
1448
1449         if (!dev_is_ide) {
1450                 scsi_scan_host(host);
1451                 return 0;
1452         }
1453         ret = scsi_add_device(host, 0, target, 0);
1454         if (ret) {
1455                 scsi_remove_host(host);
1456                 goto err_out;
1457         }
1458         return 0;
1459
1460 err_out:
1461         storvsc_dev_remove(device);
1462         kmem_cache_destroy(host_dev->request_pool);
1463         scsi_host_put(host);
1464         return -ENODEV;
1465 }
1466
1467 /* The one and only one */
1468
1469 static struct hv_driver storvsc_drv = {
1470         .name = "storvsc",
1471         .id_table = id_table,
1472         .probe = storvsc_probe,
1473         .remove = storvsc_remove,
1474 };
1475
1476 static int __init storvsc_drv_init(void)
1477 {
1478         u32 max_outstanding_req_per_channel;
1479
1480         /*
1481          * Divide the ring buffer data size (which is 1 page less
1482          * than the ring buffer size since that page is reserved for
1483          * the ring buffer indices) by the max request size (which is
1484          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1485          */
1486         max_outstanding_req_per_channel =
1487                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1488                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1489                 sizeof(struct vstor_packet) + sizeof(u64),
1490                 sizeof(u64)));
1491
1492         if (max_outstanding_req_per_channel <
1493             STORVSC_MAX_IO_REQUESTS)
1494                 return -EINVAL;
1495
1496         return vmbus_driver_register(&storvsc_drv);
1497 }
1498
1499 static void __exit storvsc_drv_exit(void)
1500 {
1501         vmbus_driver_unregister(&storvsc_drv);
1502 }
1503
1504 MODULE_LICENSE("GPL");
1505 MODULE_VERSION(HV_DRV_VERSION);
1506 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1507 module_init(storvsc_drv_init);
1508 module_exit(storvsc_drv_exit);