drivers/scsi/storvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *   K. Y. Srinivasan <kys@microsoft.com>
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/wait.h>
  25 #include <linux/sched.h>
  26 #include <linux/completion.h>
  27 #include <linux/string.h>
  28 #include <linux/mm.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/device.h>
  34 #include <linux/hyperv.h>
  35 #include <linux/mempool.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_tcq.h>
  41 #include <scsi/scsi_eh.h>
  42 #include <scsi/scsi_devinfo.h>
  43 #include <scsi/scsi_dbg.h>
  44
  45 /*
  46  * All wire protocol details (storage protocol between the guest and the host)
  47  * are consolidated here.
  48  *
  49  * Begin protocol definitions.
  50  */
  51
  52 /*
  53  * Version history:
  54  * V1 Beta: 0.1
  55  * V1 RC < 2008/1/31: 1.0
  56  * V1 RC > 2008/1/31:  2.0
  57  * Win7: 4.2
  58  */
  59
  60 #define VMSTOR_CURRENT_MAJOR  4
  61 #define VMSTOR_CURRENT_MINOR  2
  62
  63
  64 /*  Packet structure describing virtual storage requests. */
  65 enum vstor_packet_operation {
  66         VSTOR_OPERATION_COMPLETE_IO             = 1,
  67         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  68         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  69         VSTOR_OPERATION_RESET_LUN               = 4,
  70         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  71         VSTOR_OPERATION_RESET_BUS               = 6,
  72         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  73         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  74         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  75         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  76         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  77         VSTOR_OPERATION_MAXIMUM                 = 11
  78 };
  79
  80 /*
  81  * Platform neutral description of a scsi request -
  82  * this remains the same across the write regardless of 32/64 bit
  83  * note: it's patterned off the SCSI_PASS_THROUGH structure
  84  */
  85 #define STORVSC_MAX_CMD_LEN                     0x10
  86 #define STORVSC_SENSE_BUFFER_SIZE               0x12
  87 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
  88
  89 struct vmscsi_request {
  90         u16 length;
  91         u8 srb_status;
  92         u8 scsi_status;
  93
  94         u8  port_number;
  95         u8  path_id;
  96         u8  target_id;
  97         u8  lun;
  98
  99         u8  cdb_length;
 100         u8  sense_info_length;
 101         u8  data_in;
 102         u8  reserved;
 103
 104         u32 data_transfer_length;
 105
 106         union {
 107                 u8 cdb[STORVSC_MAX_CMD_LEN];
 108                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 109                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 110         };
 111 } __attribute((packed));
 112
 113
 114 /*
 115  * This structure is sent during the intialization phase to get the different
 116  * properties of the channel.
 117  */
 118 struct vmstorage_channel_properties {
 119         u16 protocol_version;
 120         u8  path_id;
 121         u8 target_id;
 122
 123         /* Note: port number is only really known on the client side */
 124         u32  port_number;
 125         u32  flags;
 126         u32   max_transfer_bytes;
 127
 128         /*
 129          * This id is unique for each channel and will correspond with
 130          * vendor specific data in the inquiry data.
 131          */
 132
 133         u64  unique_id;
 134 } __packed;
 135
 136 /*  This structure is sent during the storage protocol negotiations. */
 137 struct vmstorage_protocol_version {
 138         /* Major (MSW) and minor (LSW) version numbers. */
 139         u16 major_minor;
 140
 141         /*
 142          * Revision number is auto-incremented whenever this file is changed
 143          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 144          * definitely indicate incompatibility--but it does indicate mismatched
 145          * builds.
 146          * This is only used on the windows side. Just set it to 0.
 147          */
 148         u16 revision;
 149 } __packed;
 150
 151 /* Channel Property Flags */
 152 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 153 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 154
 155 struct vstor_packet {
 156         /* Requested operation type */
 157         enum vstor_packet_operation operation;
 158
 159         /*  Flags - see below for values */
 160         u32 flags;
 161
 162         /* Status of the request returned from the server side. */
 163         u32 status;
 164
 165         /* Data payload area */
 166         union {
 167                 /*
 168                  * Structure used to forward SCSI commands from the
 169                  * client to the server.
 170                  */
 171                 struct vmscsi_request vm_srb;
 172
 173                 /* Structure used to query channel properties. */
 174                 struct vmstorage_channel_properties storage_channel_properties;
 175
 176                 /* Used during version negotiations. */
 177                 struct vmstorage_protocol_version version;
 178         };
 179 } __packed;
 180
 181 /*
 182  * Packet Flags:
 183  *
 184  * This flag indicates that the server should send back a completion for this
 185  * packet.
 186  */
 187
 188 #define REQUEST_COMPLETION_FLAG 0x1
 189
 190 /* Matches Windows-end */
 191 enum storvsc_request_type {
 192         WRITE_TYPE = 0,
 193         READ_TYPE,
 194         UNKNOWN_TYPE,
 195 };
 196
 197 /*
 198  * SRB status codes and masks; a subset of the codes used here.
 199  */
 200
 201 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 202 #define SRB_STATUS_INVALID_LUN  0x20
 203 #define SRB_STATUS_SUCCESS      0x01
 204 #define SRB_STATUS_ERROR        0x04
 205
 206 /*
 207  * This is the end of Protocol specific defines.
 208  */
 209
 210
 211 /*
 212  * We setup a mempool to allocate request structures for this driver
 213  * on a per-lun basis. The following define specifies the number of
 214  * elements in the pool.
 215  */
 216
 217 #define STORVSC_MIN_BUF_NR                              64
 218 static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
 219
 220 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 221 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 222
 223 #define STORVSC_MAX_IO_REQUESTS                         128
 224
 225 /*
 226  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
 227  * reality, the path/target is not used (ie always set to 0) so our
 228  * scsi host adapter essentially has 1 bus with 1 target that contains
 229  * up to 256 luns.
 230  */
 231 #define STORVSC_MAX_LUNS_PER_TARGET                     64
 232 #define STORVSC_MAX_TARGETS                             1
 233 #define STORVSC_MAX_CHANNELS                            1
 234
 235
 236
 237 struct storvsc_cmd_request {
 238         struct list_head entry;
 239         struct scsi_cmnd *cmd;
 240
 241         unsigned int bounce_sgl_count;
 242         struct scatterlist *bounce_sgl;
 243
 244         struct hv_device *device;
 245
 246         /* Synchronize the request/response if needed */
 247         struct completion wait_event;
 248
 249         unsigned char *sense_buffer;
 250         struct hv_multipage_buffer data_buffer;
 251         struct vstor_packet vstor_packet;
 252 };
 253
 254
 255 /* A storvsc device is a device object that contains a vmbus channel */
 256 struct storvsc_device {
 257         struct hv_device *device;
 258
 259         bool     destroy;
 260         bool     drain_notify;
 261         atomic_t num_outstanding_req;
 262         struct Scsi_Host *host;
 263
 264         wait_queue_head_t waiting_to_drain;
 265
 266         /*
 267          * Each unique Port/Path/Target represents 1 channel ie scsi
 268          * controller. In reality, the pathid, targetid is always 0
 269          * and the port is set by us
 270          */
 271         unsigned int port_number;
 272         unsigned char path_id;
 273         unsigned char target_id;
 274
 275         /* Used for vsc/vsp channel reset process */
 276         struct storvsc_cmd_request init_request;
 277         struct storvsc_cmd_request reset_request;
 278 };
 279
 280 struct stor_mem_pools {
 281         struct kmem_cache *request_pool;
 282         mempool_t *request_mempool;
 283 };
 284
 285 struct hv_host_device {
 286         struct hv_device *dev;
 287         unsigned int port;
 288         unsigned char path;
 289         unsigned char target;
 290 };
 291
 292 struct storvsc_scan_work {
 293         struct work_struct work;
 294         struct Scsi_Host *host;
 295         uint lun;
 296 };
 297
 298 static void storvsc_bus_scan(struct work_struct *work)
 299 {
 300         struct storvsc_scan_work *wrk;
 301         int id, order_id;
 302
 303         wrk = container_of(work, struct storvsc_scan_work, work);
 304         for (id = 0; id < wrk->host->max_id; ++id) {
 305                 if (wrk->host->reverse_ordering)
 306                         order_id = wrk->host->max_id - id - 1;
 307                 else
 308                         order_id = id;
 309
 310                 scsi_scan_target(&wrk->host->shost_gendev, 0,
 311                                 order_id, SCAN_WILD_CARD, 1);
 312         }
 313         kfree(wrk);
 314 }
 315
 316 static void storvsc_remove_lun(struct work_struct *work)
 317 {
 318         struct storvsc_scan_work *wrk;
 319         struct scsi_device *sdev;
 320
 321         wrk = container_of(work, struct storvsc_scan_work, work);
 322         if (!scsi_host_get(wrk->host))
 323                 goto done;
 324
 325         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 326
 327         if (sdev) {
 328                 scsi_remove_device(sdev);
 329                 scsi_device_put(sdev);
 330         }
 331         scsi_host_put(wrk->host);
 332
 333 done:
 334         kfree(wrk);
 335 }
 336
 337 /*
 338  * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 339  * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 340  */
 341
 342 static inline u16 storvsc_get_version(u8 major, u8 minor)
 343 {
 344         u16 version;
 345
 346         version = ((major << 8) | minor);
 347         return version;
 348 }
 349
 350 /*
 351  * We can get incoming messages from the host that are not in response to
 352  * messages that we have sent out. An example of this would be messages
 353  * received by the guest to notify dynamic addition/removal of LUNs. To
 354  * deal with potential race conditions where the driver may be in the
 355  * midst of being unloaded when we might receive an unsolicited message
 356  * from the host, we have implemented a mechanism to gurantee sequential
 357  * consistency:
 358  *
 359  * 1) Once the device is marked as being destroyed, we will fail all
 360  *    outgoing messages.
 361  * 2) We permit incoming messages when the device is being destroyed,
 362  *    only to properly account for messages already sent out.
 363  */
 364
 365 static inline struct storvsc_device *get_out_stor_device(
 366                                         struct hv_device *device)
 367 {
 368         struct storvsc_device *stor_device;
 369
 370         stor_device = hv_get_drvdata(device);
 371
 372         if (stor_device && stor_device->destroy)
 373                 stor_device = NULL;
 374
 375         return stor_device;
 376 }
 377
 378
 379 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 380 {
 381         dev->drain_notify = true;
 382         wait_event(dev->waiting_to_drain,
 383                    atomic_read(&dev->num_outstanding_req) == 0);
 384         dev->drain_notify = false;
 385 }
 386
 387 static inline struct storvsc_device *get_in_stor_device(
 388                                         struct hv_device *device)
 389 {
 390         struct storvsc_device *stor_device;
 391
 392         stor_device = hv_get_drvdata(device);
 393
 394         if (!stor_device)
 395                 goto get_in_err;
 396
 397         /*
 398          * If the device is being destroyed; allow incoming
 399          * traffic only to cleanup outstanding requests.
 400          */
 401
 402         if (stor_device->destroy  &&
 403                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 404                 stor_device = NULL;
 405
 406 get_in_err:
 407         return stor_device;
 408
 409 }
 410
 411 static void destroy_bounce_buffer(struct scatterlist *sgl,
 412                                   unsigned int sg_count)
 413 {
 414         int i;
 415         struct page *page_buf;
 416
 417         for (i = 0; i < sg_count; i++) {
 418                 page_buf = sg_page((&sgl[i]));
 419                 if (page_buf != NULL)
 420                         __free_page(page_buf);
 421         }
 422
 423         kfree(sgl);
 424 }
 425
 426 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 427 {
 428         int i;
 429
 430         /* No need to check */
 431         if (sg_count < 2)
 432                 return -1;
 433
 434         /* We have at least 2 sg entries */
 435         for (i = 0; i < sg_count; i++) {
 436                 if (i == 0) {
 437                         /* make sure 1st one does not have hole */
 438                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 439                                 return i;
 440                 } else if (i == sg_count - 1) {
 441                         /* make sure last one does not have hole */
 442                         if (sgl[i].offset != 0)
 443                                 return i;
 444                 } else {
 445                         /* make sure no hole in the middle */
 446                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 447                                 return i;
 448                 }
 449         }
 450         return -1;
 451 }
 452
 453 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 454                                                 unsigned int sg_count,
 455                                                 unsigned int len,
 456                                                 int write)
 457 {
 458         int i;
 459         int num_pages;
 460         struct scatterlist *bounce_sgl;
 461         struct page *page_buf;
 462         unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 463
 464         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 465
 466         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 467         if (!bounce_sgl)
 468                 return NULL;
 469
 470         for (i = 0; i < num_pages; i++) {
 471                 page_buf = alloc_page(GFP_ATOMIC);
 472                 if (!page_buf)
 473                         goto cleanup;
 474                 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 475         }
 476
 477         return bounce_sgl;
 478
 479 cleanup:
 480         destroy_bounce_buffer(bounce_sgl, num_pages);
 481         return NULL;
 482 }
 483
 484 /* Disgusting wrapper functions */
 485 static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
 486 {
 487         void *addr = kmap_atomic(sg_page(sgl + idx));
 488         return (unsigned long)addr;
 489 }
 490
 491 static inline void sg_kunmap_atomic(unsigned long addr)
 492 {
 493         kunmap_atomic((void *)addr);
 494 }
 495
 496
 497 /* Assume the original sgl has enough room */
 498 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 499                                             struct scatterlist *bounce_sgl,
 500                                             unsigned int orig_sgl_count,
 501                                             unsigned int bounce_sgl_count)
 502 {
 503         int i;
 504         int j = 0;
 505         unsigned long src, dest;
 506         unsigned int srclen, destlen, copylen;
 507         unsigned int total_copied = 0;
 508         unsigned long bounce_addr = 0;
 509         unsigned long dest_addr = 0;
 510         unsigned long flags;
 511
 512         local_irq_save(flags);
 513
 514         for (i = 0; i < orig_sgl_count; i++) {
 515                 dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 516                 dest = dest_addr;
 517                 destlen = orig_sgl[i].length;
 518
 519                 if (bounce_addr == 0)
 520                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 521
 522                 while (destlen) {
 523                         src = bounce_addr + bounce_sgl[j].offset;
 524                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 525
 526                         copylen = min(srclen, destlen);
 527                         memcpy((void *)dest, (void *)src, copylen);
 528
 529                         total_copied += copylen;
 530                         bounce_sgl[j].offset += copylen;
 531                         destlen -= copylen;
 532                         dest += copylen;
 533
 534                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 535                                 /* full */
 536                                 sg_kunmap_atomic(bounce_addr);
 537                                 j++;
 538
 539                                 /*
 540                                  * It is possible that the number of elements
 541                                  * in the bounce buffer may not be equal to
 542                                  * the number of elements in the original
 543                                  * scatter list. Handle this correctly.
 544                                  */
 545
 546                                 if (j == bounce_sgl_count) {
 547                                         /*
 548                                          * We are done; cleanup and return.
 549                                          */
 550                                         sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 551                                         local_irq_restore(flags);
 552                                         return total_copied;
 553                                 }
 554
 555                                 /* if we need to use another bounce buffer */
 556                                 if (destlen || i != orig_sgl_count - 1)
 557                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 558                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 559                                 /* unmap the last bounce that is < PAGE_SIZE */
 560                                 sg_kunmap_atomic(bounce_addr);
 561                         }
 562                 }
 563
 564                 sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 565         }
 566
 567         local_irq_restore(flags);
 568
 569         return total_copied;
 570 }
 571
 572 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 573 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 574                                           struct scatterlist *bounce_sgl,
 575                                           unsigned int orig_sgl_count)
 576 {
 577         int i;
 578         int j = 0;
 579         unsigned long src, dest;
 580         unsigned int srclen, destlen, copylen;
 581         unsigned int total_copied = 0;
 582         unsigned long bounce_addr = 0;
 583         unsigned long src_addr = 0;
 584         unsigned long flags;
 585
 586         local_irq_save(flags);
 587
 588         for (i = 0; i < orig_sgl_count; i++) {
 589                 src_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 590                 src = src_addr;
 591                 srclen = orig_sgl[i].length;
 592
 593                 if (bounce_addr == 0)
 594                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 595
 596                 while (srclen) {
 597                         /* assume bounce offset always == 0 */
 598                         dest = bounce_addr + bounce_sgl[j].length;
 599                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 600
 601                         copylen = min(srclen, destlen);
 602                         memcpy((void *)dest, (void *)src, copylen);
 603
 604                         total_copied += copylen;
 605                         bounce_sgl[j].length += copylen;
 606                         srclen -= copylen;
 607                         src += copylen;
 608
 609                         if (bounce_sgl[j].length == PAGE_SIZE) {
 610                                 /* full..move to next entry */
 611                                 sg_kunmap_atomic(bounce_addr);
 612                                 j++;
 613
 614                                 /* if we need to use another bounce buffer */
 615                                 if (srclen || i != orig_sgl_count - 1)
 616                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 617
 618                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 619                                 /* unmap the last bounce that is < PAGE_SIZE */
 620                                 sg_kunmap_atomic(bounce_addr);
 621                         }
 622                 }
 623
 624                 sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
 625         }
 626
 627         local_irq_restore(flags);
 628
 629         return total_copied;
 630 }
 631
 632 static int storvsc_channel_init(struct hv_device *device)
 633 {
 634         struct storvsc_device *stor_device;
 635         struct storvsc_cmd_request *request;
 636         struct vstor_packet *vstor_packet;
 637         int ret, t;
 638
 639         stor_device = get_out_stor_device(device);
 640         if (!stor_device)
 641                 return -ENODEV;
 642
 643         request = &stor_device->init_request;
 644         vstor_packet = &request->vstor_packet;
 645
 646         /*
 647          * Now, initiate the vsc/vsp initialization protocol on the open
 648          * channel
 649          */
 650         memset(request, 0, sizeof(struct storvsc_cmd_request));
 651         init_completion(&request->wait_event);
 652         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 653         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 654
 655         ret = vmbus_sendpacket(device->channel, vstor_packet,
 656                                sizeof(struct vstor_packet),
 657                                (unsigned long)request,
 658                                VM_PKT_DATA_INBAND,
 659                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 660         if (ret != 0)
 661                 goto cleanup;
 662
 663         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 664         if (t == 0) {
 665                 ret = -ETIMEDOUT;
 666                 goto cleanup;
 667         }
 668
 669         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 670             vstor_packet->status != 0)
 671                 goto cleanup;
 672
 673
 674         /* reuse the packet for version range supported */
 675         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 676         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 677         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 678
 679         vstor_packet->version.major_minor =
 680                 storvsc_get_version(VMSTOR_CURRENT_MAJOR, VMSTOR_CURRENT_MINOR);
 681
 682         /*
 683          * The revision number is only used in Windows; set it to 0.
 684          */
 685         vstor_packet->version.revision = 0;
 686
 687         ret = vmbus_sendpacket(device->channel, vstor_packet,
 688                                sizeof(struct vstor_packet),
 689                                (unsigned long)request,
 690                                VM_PKT_DATA_INBAND,
 691                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 692         if (ret != 0)
 693                 goto cleanup;
 694
 695         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 696         if (t == 0) {
 697                 ret = -ETIMEDOUT;
 698                 goto cleanup;
 699         }
 700
 701         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 702             vstor_packet->status != 0)
 703                 goto cleanup;
 704
 705
 706         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 707         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 708         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 709         vstor_packet->storage_channel_properties.port_number =
 710                                         stor_device->port_number;
 711
 712         ret = vmbus_sendpacket(device->channel, vstor_packet,
 713                                sizeof(struct vstor_packet),
 714                                (unsigned long)request,
 715                                VM_PKT_DATA_INBAND,
 716                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 717
 718         if (ret != 0)
 719                 goto cleanup;
 720
 721         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 722         if (t == 0) {
 723                 ret = -ETIMEDOUT;
 724                 goto cleanup;
 725         }
 726
 727         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 728             vstor_packet->status != 0)
 729                 goto cleanup;
 730
 731         stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
 732         stor_device->target_id
 733                 = vstor_packet->storage_channel_properties.target_id;
 734
 735         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 736         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 737         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 738
 739         ret = vmbus_sendpacket(device->channel, vstor_packet,
 740                                sizeof(struct vstor_packet),
 741                                (unsigned long)request,
 742                                VM_PKT_DATA_INBAND,
 743                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 744
 745         if (ret != 0)
 746                 goto cleanup;
 747
 748         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 749         if (t == 0) {
 750                 ret = -ETIMEDOUT;
 751                 goto cleanup;
 752         }
 753
 754         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 755             vstor_packet->status != 0)
 756                 goto cleanup;
 757
 758
 759 cleanup:
 760         return ret;
 761 }
 762
 763
 764 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
 765 {
 766         struct scsi_cmnd *scmnd = cmd_request->cmd;
 767         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
 768         void (*scsi_done_fn)(struct scsi_cmnd *);
 769         struct scsi_sense_hdr sense_hdr;
 770         struct vmscsi_request *vm_srb;
 771         struct storvsc_scan_work *wrk;
 772         struct stor_mem_pools *memp = scmnd->device->hostdata;
 773
 774         vm_srb = &cmd_request->vstor_packet.vm_srb;
 775         if (cmd_request->bounce_sgl_count) {
 776                 if (vm_srb->data_in == READ_TYPE)
 777                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 778                                         cmd_request->bounce_sgl,
 779                                         scsi_sg_count(scmnd),
 780                                         cmd_request->bounce_sgl_count);
 781                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 782                                         cmd_request->bounce_sgl_count);
 783         }
 784
 785         /*
 786          * If there is an error; offline the device since all
 787          * error recovery strategies would have already been
 788          * deployed on the host side. However, if the command
 789          * were a pass-through command deal with it appropriately.
 790          */
 791         scmnd->result = vm_srb->scsi_status;
 792
 793         if (vm_srb->srb_status == SRB_STATUS_ERROR) {
 794                 switch (scmnd->cmnd[0]) {
 795                 case ATA_16:
 796                 case ATA_12:
 797                         set_host_byte(scmnd, DID_PASSTHROUGH);
 798                         break;
 799                 default:
 800                         set_host_byte(scmnd, DID_TARGET_FAILURE);
 801                 }
 802         }
 803
 804
 805         /*
 806          * If the LUN is invalid; remove the device.
 807          */
 808         if (vm_srb->srb_status == SRB_STATUS_INVALID_LUN) {
 809                 struct storvsc_device *stor_dev;
 810                 struct hv_device *dev = host_dev->dev;
 811                 struct Scsi_Host *host;
 812
 813                 stor_dev = get_in_stor_device(dev);
 814                 host = stor_dev->host;
 815
 816                 wrk = kmalloc(sizeof(struct storvsc_scan_work),
 817                                 GFP_ATOMIC);
 818                 if (!wrk) {
 819                         scmnd->result = DID_TARGET_FAILURE << 16;
 820                 } else {
 821                         wrk->host = host;
 822                         wrk->lun = vm_srb->lun;
 823                         INIT_WORK(&wrk->work, storvsc_remove_lun);
 824                         schedule_work(&wrk->work);
 825                 }
 826         }
 827
 828         if (scmnd->result) {
 829                 if (scsi_normalize_sense(scmnd->sense_buffer,
 830                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
 831                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 832         }
 833
 834         scsi_set_resid(scmnd,
 835                 cmd_request->data_buffer.len -
 836                 vm_srb->data_transfer_length);
 837
 838         scsi_done_fn = scmnd->scsi_done;
 839
 840         scmnd->host_scribble = NULL;
 841         scmnd->scsi_done = NULL;
 842
 843         scsi_done_fn(scmnd);
 844
 845         mempool_free(cmd_request, memp->request_mempool);
 846 }
 847
 848 static void storvsc_on_io_completion(struct hv_device *device,
 849                                   struct vstor_packet *vstor_packet,
 850                                   struct storvsc_cmd_request *request)
 851 {
 852         struct storvsc_device *stor_device;
 853         struct vstor_packet *stor_pkt;
 854
 855         stor_device = hv_get_drvdata(device);
 856         stor_pkt = &request->vstor_packet;
 857
 858         /*
 859          * The current SCSI handling on the host side does
 860          * not correctly handle:
 861          * INQUIRY command with page code parameter set to 0x80
 862          * MODE_SENSE command with cmd[2] == 0x1c
 863          *
 864          * Setup srb and scsi status so this won't be fatal.
 865          * We do this so we can distinguish truly fatal failues
 866          * (srb status == 0x4) and off-line the device in that case.
 867          */
 868
 869         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
 870            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
 871                 vstor_packet->vm_srb.scsi_status = 0;
 872                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
 873         }
 874
 875
 876         /* Copy over the status...etc */
 877         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 878         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 879         stor_pkt->vm_srb.sense_info_length =
 880         vstor_packet->vm_srb.sense_info_length;
 881
 882         if (vstor_packet->vm_srb.scsi_status != 0 ||
 883                 vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS){
 884                 dev_warn(&device->device,
 885                          "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 886                          stor_pkt->vm_srb.cdb[0],
 887                          vstor_packet->vm_srb.scsi_status,
 888                          vstor_packet->vm_srb.srb_status);
 889         }
 890
 891         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 892                 /* CHECK_CONDITION */
 893                 if (vstor_packet->vm_srb.srb_status &
 894                         SRB_STATUS_AUTOSENSE_VALID) {
 895                         /* autosense data available */
 896                         dev_warn(&device->device,
 897                                  "stor pkt %p autosense data valid - len %d\n",
 898                                  request,
 899                                  vstor_packet->vm_srb.sense_info_length);
 900
 901                         memcpy(request->sense_buffer,
 902                                vstor_packet->vm_srb.sense_data,
 903                                vstor_packet->vm_srb.sense_info_length);
 904
 905                 }
 906         }
 907
 908         stor_pkt->vm_srb.data_transfer_length =
 909         vstor_packet->vm_srb.data_transfer_length;
 910
 911         storvsc_command_completion(request);
 912
 913         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 914                 stor_device->drain_notify)
 915                 wake_up(&stor_device->waiting_to_drain);
 916
 917
 918 }
 919
 920 static void storvsc_on_receive(struct hv_device *device,
 921                              struct vstor_packet *vstor_packet,
 922                              struct storvsc_cmd_request *request)
 923 {
 924         struct storvsc_scan_work *work;
 925         struct storvsc_device *stor_device;
 926
 927         switch (vstor_packet->operation) {
 928         case VSTOR_OPERATION_COMPLETE_IO:
 929                 storvsc_on_io_completion(device, vstor_packet, request);
 930                 break;
 931
 932         case VSTOR_OPERATION_REMOVE_DEVICE:
 933         case VSTOR_OPERATION_ENUMERATE_BUS:
 934                 stor_device = get_in_stor_device(device);
 935                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 936                 if (!work)
 937                         return;
 938
 939                 INIT_WORK(&work->work, storvsc_bus_scan);
 940                 work->host = stor_device->host;
 941                 schedule_work(&work->work);
 942                 break;
 943
 944         default:
 945                 break;
 946         }
 947 }
 948
 949 static void storvsc_on_channel_callback(void *context)
 950 {
 951         struct hv_device *device = (struct hv_device *)context;
 952         struct storvsc_device *stor_device;
 953         u32 bytes_recvd;
 954         u64 request_id;
 955         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 956         struct storvsc_cmd_request *request;
 957         int ret;
 958
 959
 960         stor_device = get_in_stor_device(device);
 961         if (!stor_device)
 962                 return;
 963
 964         do {
 965                 ret = vmbus_recvpacket(device->channel, packet,
 966                                        ALIGN(sizeof(struct vstor_packet), 8),
 967                                        &bytes_recvd, &request_id);
 968                 if (ret == 0 && bytes_recvd > 0) {
 969
 970                         request = (struct storvsc_cmd_request *)
 971                                         (unsigned long)request_id;
 972
 973                         if ((request == &stor_device->init_request) ||
 974                             (request == &stor_device->reset_request)) {
 975
 976                                 memcpy(&request->vstor_packet, packet,
 977                                        sizeof(struct vstor_packet));
 978                                 complete(&request->wait_event);
 979                         } else {
 980                                 storvsc_on_receive(device,
 981                                                 (struct vstor_packet *)packet,
 982                                                 request);
 983                         }
 984                 } else {
 985                         break;
 986                 }
 987         } while (1);
 988
 989         return;
 990 }
 991
 992 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 993 {
 994         struct vmstorage_channel_properties props;
 995         int ret;
 996
 997         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 998
 999         ret = vmbus_open(device->channel,
1000                          ring_size,
1001                          ring_size,
1002                          (void *)&props,
1003                          sizeof(struct vmstorage_channel_properties),
1004                          storvsc_on_channel_callback, device);
1005
1006         if (ret != 0)
1007                 return ret;
1008
1009         ret = storvsc_channel_init(device);
1010
1011         return ret;
1012 }
1013
1014 static int storvsc_dev_remove(struct hv_device *device)
1015 {
1016         struct storvsc_device *stor_device;
1017         unsigned long flags;
1018
1019         stor_device = hv_get_drvdata(device);
1020
1021         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1022         stor_device->destroy = true;
1023         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1024
1025         /*
1026          * At this point, all outbound traffic should be disable. We
1027          * only allow inbound traffic (responses) to proceed so that
1028          * outstanding requests can be completed.
1029          */
1030
1031         storvsc_wait_to_drain(stor_device);
1032
1033         /*
1034          * Since we have already drained, we don't need to busy wait
1035          * as was done in final_release_stor_device()
1036          * Note that we cannot set the ext pointer to NULL until
1037          * we have drained - to drain the outgoing packets, we need to
1038          * allow incoming packets.
1039          */
1040         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1041         hv_set_drvdata(device, NULL);
1042         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1043
1044         /* Close the channel */
1045         vmbus_close(device->channel);
1046
1047         kfree(stor_device);
1048         return 0;
1049 }
1050
1051 static int storvsc_do_io(struct hv_device *device,
1052                               struct storvsc_cmd_request *request)
1053 {
1054         struct storvsc_device *stor_device;
1055         struct vstor_packet *vstor_packet;
1056         int ret = 0;
1057
1058         vstor_packet = &request->vstor_packet;
1059         stor_device = get_out_stor_device(device);
1060
1061         if (!stor_device)
1062                 return -ENODEV;
1063
1064
1065         request->device  = device;
1066
1067
1068         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1069
1070         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1071
1072
1073         vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1074
1075
1076         vstor_packet->vm_srb.data_transfer_length =
1077         request->data_buffer.len;
1078
1079         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1080
1081         if (request->data_buffer.len) {
1082                 ret = vmbus_sendpacket_multipagebuffer(device->channel,
1083                                 &request->data_buffer,
1084                                 vstor_packet,
1085                                 sizeof(struct vstor_packet),
1086                                 (unsigned long)request);
1087         } else {
1088                 ret = vmbus_sendpacket(device->channel, vstor_packet,
1089                                sizeof(struct vstor_packet),
1090                                (unsigned long)request,
1091                                VM_PKT_DATA_INBAND,
1092                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1093         }
1094
1095         if (ret != 0)
1096                 return ret;
1097
1098         atomic_inc(&stor_device->num_outstanding_req);
1099
1100         return ret;
1101 }
1102
1103 static int storvsc_device_alloc(struct scsi_device *sdevice)
1104 {
1105         struct stor_mem_pools *memp;
1106         int number = STORVSC_MIN_BUF_NR;
1107
1108         memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
1109         if (!memp)
1110                 return -ENOMEM;
1111
1112         memp->request_pool =
1113                 kmem_cache_create(dev_name(&sdevice->sdev_dev),
1114                                 sizeof(struct storvsc_cmd_request), 0,
1115                                 SLAB_HWCACHE_ALIGN, NULL);
1116
1117         if (!memp->request_pool)
1118                 goto err0;
1119
1120         memp->request_mempool = mempool_create(number, mempool_alloc_slab,
1121                                                 mempool_free_slab,
1122                                                 memp->request_pool);
1123
1124         if (!memp->request_mempool)
1125                 goto err1;
1126
1127         sdevice->hostdata = memp;
1128
1129         return 0;
1130
1131 err1:
1132         kmem_cache_destroy(memp->request_pool);
1133
1134 err0:
1135         kfree(memp);
1136         return -ENOMEM;
1137 }
1138
1139 static void storvsc_device_destroy(struct scsi_device *sdevice)
1140 {
1141         struct stor_mem_pools *memp = sdevice->hostdata;
1142
1143         mempool_destroy(memp->request_mempool);
1144         kmem_cache_destroy(memp->request_pool);
1145         kfree(memp);
1146         sdevice->hostdata = NULL;
1147 }
1148
1149 static int storvsc_device_configure(struct scsi_device *sdevice)
1150 {
1151         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
1152                                 STORVSC_MAX_IO_REQUESTS);
1153
1154         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1155
1156         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1157
1158         return 0;
1159 }
1160
1161 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1162                            sector_t capacity, int *info)
1163 {
1164         sector_t nsect = capacity;
1165         sector_t cylinders = nsect;
1166         int heads, sectors_pt;
1167
1168         /*
1169          * We are making up these values; let us keep it simple.
1170          */
1171         heads = 0xff;
1172         sectors_pt = 0x3f;      /* Sectors per track */
1173         sector_div(cylinders, heads * sectors_pt);
1174         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1175                 cylinders = 0xffff;
1176
1177         info[0] = heads;
1178         info[1] = sectors_pt;
1179         info[2] = (int)cylinders;
1180
1181         return 0;
1182 }
1183
1184 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1185 {
1186         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1187         struct hv_device *device = host_dev->dev;
1188
1189         struct storvsc_device *stor_device;
1190         struct storvsc_cmd_request *request;
1191         struct vstor_packet *vstor_packet;
1192         int ret, t;
1193
1194
1195         stor_device = get_out_stor_device(device);
1196         if (!stor_device)
1197                 return FAILED;
1198
1199         request = &stor_device->reset_request;
1200         vstor_packet = &request->vstor_packet;
1201
1202         init_completion(&request->wait_event);
1203
1204         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1205         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1206         vstor_packet->vm_srb.path_id = stor_device->path_id;
1207
1208         ret = vmbus_sendpacket(device->channel, vstor_packet,
1209                                sizeof(struct vstor_packet),
1210                                (unsigned long)&stor_device->reset_request,
1211                                VM_PKT_DATA_INBAND,
1212                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1213         if (ret != 0)
1214                 return FAILED;
1215
1216         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1217         if (t == 0)
1218                 return TIMEOUT_ERROR;
1219
1220
1221         /*
1222          * At this point, all outstanding requests in the adapter
1223          * should have been flushed out and return to us
1224          * There is a potential race here where the host may be in
1225          * the process of responding when we return from here.
1226          * Just wait for all in-transit packets to be accounted for
1227          * before we return from here.
1228          */
1229         storvsc_wait_to_drain(stor_device);
1230
1231         return SUCCESS;
1232 }
1233
1234 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1235 {
1236         bool allowed = true;
1237         u8 scsi_op = scmnd->cmnd[0];
1238
1239         switch (scsi_op) {
1240         /*
1241          * smartd sends this command and the host does not handle
1242          * this. So, don't send it.
1243          */
1244         case SET_WINDOW:
1245                 scmnd->result = ILLEGAL_REQUEST << 16;
1246                 allowed = false;
1247                 break;
1248         default:
1249                 break;
1250         }
1251         return allowed;
1252 }
1253
1254 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1255 {
1256         int ret;
1257         struct hv_host_device *host_dev = shost_priv(host);
1258         struct hv_device *dev = host_dev->dev;
1259         struct storvsc_cmd_request *cmd_request;
1260         unsigned int request_size = 0;
1261         int i;
1262         struct scatterlist *sgl;
1263         unsigned int sg_count = 0;
1264         struct vmscsi_request *vm_srb;
1265         struct stor_mem_pools *memp = scmnd->device->hostdata;
1266
1267         if (!storvsc_scsi_cmd_ok(scmnd)) {
1268                 scmnd->scsi_done(scmnd);
1269                 return 0;
1270         }
1271
1272         request_size = sizeof(struct storvsc_cmd_request);
1273
1274         cmd_request = mempool_alloc(memp->request_mempool,
1275                                        GFP_ATOMIC);
1276
1277         /*
1278          * We might be invoked in an interrupt context; hence
1279          * mempool_alloc() can fail.
1280          */
1281         if (!cmd_request)
1282                 return SCSI_MLQUEUE_DEVICE_BUSY;
1283
1284         memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
1285
1286         /* Setup the cmd request */
1287         cmd_request->cmd = scmnd;
1288
1289         scmnd->host_scribble = (unsigned char *)cmd_request;
1290
1291         vm_srb = &cmd_request->vstor_packet.vm_srb;
1292
1293
1294         /* Build the SRB */
1295         switch (scmnd->sc_data_direction) {
1296         case DMA_TO_DEVICE:
1297                 vm_srb->data_in = WRITE_TYPE;
1298                 break;
1299         case DMA_FROM_DEVICE:
1300                 vm_srb->data_in = READ_TYPE;
1301                 break;
1302         default:
1303                 vm_srb->data_in = UNKNOWN_TYPE;
1304                 break;
1305         }
1306
1307
1308         vm_srb->port_number = host_dev->port;
1309         vm_srb->path_id = scmnd->device->channel;
1310         vm_srb->target_id = scmnd->device->id;
1311         vm_srb->lun = scmnd->device->lun;
1312
1313         vm_srb->cdb_length = scmnd->cmd_len;
1314
1315         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1316
1317         cmd_request->sense_buffer = scmnd->sense_buffer;
1318
1319
1320         cmd_request->data_buffer.len = scsi_bufflen(scmnd);
1321         if (scsi_sg_count(scmnd)) {
1322                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1323                 sg_count = scsi_sg_count(scmnd);
1324
1325                 /* check if we need to bounce the sgl */
1326                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1327                         cmd_request->bounce_sgl =
1328                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1329                                                      scsi_bufflen(scmnd),
1330                                                      vm_srb->data_in);
1331                         if (!cmd_request->bounce_sgl) {
1332                                 ret = SCSI_MLQUEUE_HOST_BUSY;
1333                                 goto queue_error;
1334                         }
1335
1336                         cmd_request->bounce_sgl_count =
1337                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1338                                         PAGE_SHIFT;
1339
1340                         if (vm_srb->data_in == WRITE_TYPE)
1341                                 copy_to_bounce_buffer(sgl,
1342                                         cmd_request->bounce_sgl,
1343                                         scsi_sg_count(scmnd));
1344
1345                         sgl = cmd_request->bounce_sgl;
1346                         sg_count = cmd_request->bounce_sgl_count;
1347                 }
1348
1349                 cmd_request->data_buffer.offset = sgl[0].offset;
1350
1351                 for (i = 0; i < sg_count; i++)
1352                         cmd_request->data_buffer.pfn_array[i] =
1353                                 page_to_pfn(sg_page((&sgl[i])));
1354
1355         } else if (scsi_sglist(scmnd)) {
1356                 cmd_request->data_buffer.offset =
1357                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1358                 cmd_request->data_buffer.pfn_array[0] =
1359                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1360         }
1361
1362         /* Invokes the vsc to start an IO */
1363         ret = storvsc_do_io(dev, cmd_request);
1364
1365         if (ret == -EAGAIN) {
1366                 /* no more space */
1367
1368                 if (cmd_request->bounce_sgl_count) {
1369                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1370                                         cmd_request->bounce_sgl_count);
1371
1372                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1373                         goto queue_error;
1374                 }
1375         }
1376
1377         return 0;
1378
1379 queue_error:
1380         mempool_free(cmd_request, memp->request_mempool);
1381         scmnd->host_scribble = NULL;
1382         return ret;
1383 }
1384
1385 static struct scsi_host_template scsi_driver = {
1386         .module =               THIS_MODULE,
1387         .name =                 "storvsc_host_t",
1388         .bios_param =           storvsc_get_chs,
1389         .queuecommand =         storvsc_queuecommand,
1390         .eh_host_reset_handler =        storvsc_host_reset_handler,
1391         .slave_alloc =          storvsc_device_alloc,
1392         .slave_destroy =        storvsc_device_destroy,
1393         .slave_configure =      storvsc_device_configure,
1394         .cmd_per_lun =          1,
1395         /* 64 max_queue * 1 target */
1396         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1397         .this_id =              -1,
1398         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1399         /* currently 32 */
1400         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1401         .use_clustering =       DISABLE_CLUSTERING,
1402         /* Make sure we dont get a sg segment crosses a page boundary */
1403         .dma_boundary =         PAGE_SIZE-1,
1404 };
1405
1406 enum {
1407         SCSI_GUID,
1408         IDE_GUID,
1409 };
1410
1411 static const struct hv_vmbus_device_id id_table[] = {
1412         /* SCSI guid */
1413         { VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
1414                        0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
1415           .driver_data = SCSI_GUID },
1416         /* IDE guid */
1417         { VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
1418                        0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
1419           .driver_data = IDE_GUID },
1420         { },
1421 };
1422
1423 MODULE_DEVICE_TABLE(vmbus, id_table);
1424
1425 static int storvsc_probe(struct hv_device *device,
1426                         const struct hv_vmbus_device_id *dev_id)
1427 {
1428         int ret;
1429         struct Scsi_Host *host;
1430         struct hv_host_device *host_dev;
1431         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1432         int target = 0;
1433         struct storvsc_device *stor_device;
1434
1435         host = scsi_host_alloc(&scsi_driver,
1436                                sizeof(struct hv_host_device));
1437         if (!host)
1438                 return -ENOMEM;
1439
1440         host_dev = shost_priv(host);
1441         memset(host_dev, 0, sizeof(struct hv_host_device));
1442
1443         host_dev->port = host->host_no;
1444         host_dev->dev = device;
1445
1446
1447         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1448         if (!stor_device) {
1449                 ret = -ENOMEM;
1450                 goto err_out0;
1451         }
1452
1453         stor_device->destroy = false;
1454         init_waitqueue_head(&stor_device->waiting_to_drain);
1455         stor_device->device = device;
1456         stor_device->host = host;
1457         hv_set_drvdata(device, stor_device);
1458
1459         stor_device->port_number = host->host_no;
1460         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1461         if (ret)
1462                 goto err_out1;
1463
1464         host_dev->path = stor_device->path_id;
1465         host_dev->target = stor_device->target_id;
1466
1467         /* max # of devices per target */
1468         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1469         /* max # of targets per channel */
1470         host->max_id = STORVSC_MAX_TARGETS;
1471         /* max # of channels */
1472         host->max_channel = STORVSC_MAX_CHANNELS - 1;
1473         /* max cmd length */
1474         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1475
1476         /* Register the HBA and start the scsi bus scan */
1477         ret = scsi_add_host(host, &device->device);
1478         if (ret != 0)
1479                 goto err_out2;
1480
1481         if (!dev_is_ide) {
1482                 scsi_scan_host(host);
1483         } else {
1484                 target = (device->dev_instance.b[5] << 8 |
1485                          device->dev_instance.b[4]);
1486                 ret = scsi_add_device(host, 0, target, 0);
1487                 if (ret) {
1488                         scsi_remove_host(host);
1489                         goto err_out2;
1490                 }
1491         }
1492         return 0;
1493
1494 err_out2:
1495         /*
1496          * Once we have connected with the host, we would need to
1497          * to invoke storvsc_dev_remove() to rollback this state and
1498          * this call also frees up the stor_device; hence the jump around
1499          * err_out1 label.
1500          */
1501         storvsc_dev_remove(device);
1502         goto err_out0;
1503
1504 err_out1:
1505         kfree(stor_device);
1506
1507 err_out0:
1508         scsi_host_put(host);
1509         return ret;
1510 }
1511
1512 static int storvsc_remove(struct hv_device *dev)
1513 {
1514         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1515         struct Scsi_Host *host = stor_device->host;
1516
1517         scsi_remove_host(host);
1518         storvsc_dev_remove(dev);
1519         scsi_host_put(host);
1520
1521         return 0;
1522 }
1523
1524 static struct hv_driver storvsc_drv = {
1525         .name = KBUILD_MODNAME,
1526         .id_table = id_table,
1527         .probe = storvsc_probe,
1528         .remove = storvsc_remove,
1529 };
1530
1531 static int __init storvsc_drv_init(void)
1532 {
1533         u32 max_outstanding_req_per_channel;
1534
1535         /*
1536          * Divide the ring buffer data size (which is 1 page less
1537          * than the ring buffer size since that page is reserved for
1538          * the ring buffer indices) by the max request size (which is
1539          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1540          */
1541         max_outstanding_req_per_channel =
1542                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1543                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1544                 sizeof(struct vstor_packet) + sizeof(u64),
1545                 sizeof(u64)));
1546
1547         if (max_outstanding_req_per_channel <
1548             STORVSC_MAX_IO_REQUESTS)
1549                 return -EINVAL;
1550
1551         return vmbus_driver_register(&storvsc_drv);
1552 }
1553
1554 static void __exit storvsc_drv_exit(void)
1555 {
1556         vmbus_driver_unregister(&storvsc_drv);
1557 }
1558
1559 MODULE_LICENSE("GPL");
1560 MODULE_VERSION(HV_DRV_VERSION);
1561 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1562 module_init(storvsc_drv_init);
1563 module_exit(storvsc_drv_exit);