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