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/blkdev.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  * Win8: 5.1
  59  */
  60
  61
  62 #define VMSTOR_WIN7_MAJOR 4
  63 #define VMSTOR_WIN7_MINOR 2
  64
  65 #define VMSTOR_WIN8_MAJOR 5
  66 #define VMSTOR_WIN8_MINOR 1
  67
  68
  69 /*  Packet structure describing virtual storage requests. */
  70 enum vstor_packet_operation {
  71         VSTOR_OPERATION_COMPLETE_IO             = 1,
  72         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  73         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  74         VSTOR_OPERATION_RESET_LUN               = 4,
  75         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  76         VSTOR_OPERATION_RESET_BUS               = 6,
  77         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  78         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  79         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  80         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  81         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  82         VSTOR_OPERATION_FCHBA_DATA              = 12,
  83         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  84         VSTOR_OPERATION_MAXIMUM                 = 13
  85 };
  86
  87 /*
  88  * WWN packet for Fibre Channel HBA
  89  */
  90
  91 struct hv_fc_wwn_packet {
  92         bool    primary_active;
  93         u8      reserved1;
  94         u8      reserved2;
  95         u8      primary_port_wwn[8];
  96         u8      primary_node_wwn[8];
  97         u8      secondary_port_wwn[8];
  98         u8      secondary_node_wwn[8];
  99 };
 100
 101
 102
 103 /*
 104  * SRB Flag Bits
 105  */
 106
 107 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 108 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 109 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 110 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 111 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 112 #define SRB_FLAGS_DATA_IN                       0x00000040
 113 #define SRB_FLAGS_DATA_OUT                      0x00000080
 114 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 115 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 116 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 117 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 118 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 119
 120 /*
 121  * This flag indicates the request is part of the workflow for processing a D3.
 122  */
 123 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 124 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 125 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 126 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 127 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 128 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 129 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 130 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 131 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 132 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 133 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 134
 135
 136 /*
 137  * Platform neutral description of a scsi request -
 138  * this remains the same across the write regardless of 32/64 bit
 139  * note: it's patterned off the SCSI_PASS_THROUGH structure
 140  */
 141 #define STORVSC_MAX_CMD_LEN                     0x10
 142
 143 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 144 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 145
 146 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 147 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 148
 149 /*
 150  * Sense buffer size changed in win8; have a run-time
 151  * variable to track the size we should use.
 152  */
 153 static int sense_buffer_size;
 154
 155 /*
 156  * The size of the vmscsi_request has changed in win8. The
 157  * additional size is because of new elements added to the
 158  * structure. These elements are valid only when we are talking
 159  * to a win8 host.
 160  * Track the correction to size we need to apply.
 161  */
 162
 163 static int vmscsi_size_delta;
 164 static int vmstor_current_major;
 165 static int vmstor_current_minor;
 166
 167 struct vmscsi_win8_extension {
 168         /*
 169          * The following were added in Windows 8
 170          */
 171         u16 reserve;
 172         u8  queue_tag;
 173         u8  queue_action;
 174         u32 srb_flags;
 175         u32 time_out_value;
 176         u32 queue_sort_ey;
 177 } __packed;
 178
 179 struct vmscsi_request {
 180         u16 length;
 181         u8 srb_status;
 182         u8 scsi_status;
 183
 184         u8  port_number;
 185         u8  path_id;
 186         u8  target_id;
 187         u8  lun;
 188
 189         u8  cdb_length;
 190         u8  sense_info_length;
 191         u8  data_in;
 192         u8  reserved;
 193
 194         u32 data_transfer_length;
 195
 196         union {
 197                 u8 cdb[STORVSC_MAX_CMD_LEN];
 198                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 199                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 200         };
 201         /*
 202          * The following was added in win8.
 203          */
 204         struct vmscsi_win8_extension win8_extension;
 205
 206 } __attribute((packed));
 207
 208
 209 /*
 210  * This structure is sent during the intialization phase to get the different
 211  * properties of the channel.
 212  */
 213
 214 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 215
 216 struct vmstorage_channel_properties {
 217         u32 reserved;
 218         u16 max_channel_cnt;
 219         u16 reserved1;
 220
 221         u32 flags;
 222         u32   max_transfer_bytes;
 223
 224         u64  reserved2;
 225 } __packed;
 226
 227 /*  This structure is sent during the storage protocol negotiations. */
 228 struct vmstorage_protocol_version {
 229         /* Major (MSW) and minor (LSW) version numbers. */
 230         u16 major_minor;
 231
 232         /*
 233          * Revision number is auto-incremented whenever this file is changed
 234          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 235          * definitely indicate incompatibility--but it does indicate mismatched
 236          * builds.
 237          * This is only used on the windows side. Just set it to 0.
 238          */
 239         u16 revision;
 240 } __packed;
 241
 242 /* Channel Property Flags */
 243 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 244 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 245
 246 struct vstor_packet {
 247         /* Requested operation type */
 248         enum vstor_packet_operation operation;
 249
 250         /*  Flags - see below for values */
 251         u32 flags;
 252
 253         /* Status of the request returned from the server side. */
 254         u32 status;
 255
 256         /* Data payload area */
 257         union {
 258                 /*
 259                  * Structure used to forward SCSI commands from the
 260                  * client to the server.
 261                  */
 262                 struct vmscsi_request vm_srb;
 263
 264                 /* Structure used to query channel properties. */
 265                 struct vmstorage_channel_properties storage_channel_properties;
 266
 267                 /* Used during version negotiations. */
 268                 struct vmstorage_protocol_version version;
 269
 270                 /* Fibre channel address packet */
 271                 struct hv_fc_wwn_packet wwn_packet;
 272
 273                 /* Number of sub-channels to create */
 274                 u16 sub_channel_count;
 275
 276                 /* This will be the maximum of the union members */
 277                 u8  buffer[0x34];
 278         };
 279 } __packed;
 280
 281 /*
 282  * Packet Flags:
 283  *
 284  * This flag indicates that the server should send back a completion for this
 285  * packet.
 286  */
 287
 288 #define REQUEST_COMPLETION_FLAG 0x1
 289
 290 /* Matches Windows-end */
 291 enum storvsc_request_type {
 292         WRITE_TYPE = 0,
 293         READ_TYPE,
 294         UNKNOWN_TYPE,
 295 };
 296
 297 /*
 298  * SRB status codes and masks; a subset of the codes used here.
 299  */
 300
 301 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 302 #define SRB_STATUS_INVALID_LUN  0x20
 303 #define SRB_STATUS_SUCCESS      0x01
 304 #define SRB_STATUS_ABORTED      0x02
 305 #define SRB_STATUS_ERROR        0x04
 306
 307 /*
 308  * This is the end of Protocol specific defines.
 309  */
 310
 311 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 312 static u32 max_outstanding_req_per_channel;
 313
 314 static int storvsc_vcpus_per_sub_channel = 4;
 315
 316 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 317 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 318
 319 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 320 MODULE_PARM_DESC(vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 321 /*
 322  * Timeout in seconds for all devices managed by this driver.
 323  */
 324 static int storvsc_timeout = 180;
 325
 326 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
 327
 328
 329 static void storvsc_on_channel_callback(void *context);
 330
 331 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 332 #define STORVSC_MAX_TARGETS                             2
 333 #define STORVSC_MAX_CHANNELS                            8
 334
 335 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 336 #define STORVSC_FC_MAX_TARGETS                          128
 337 #define STORVSC_FC_MAX_CHANNELS                         8
 338
 339 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 340 #define STORVSC_IDE_MAX_TARGETS                         1
 341 #define STORVSC_IDE_MAX_CHANNELS                        1
 342
 343 struct storvsc_cmd_request {
 344         struct scsi_cmnd *cmd;
 345
 346         unsigned int bounce_sgl_count;
 347         struct scatterlist *bounce_sgl;
 348
 349         struct hv_device *device;
 350
 351         /* Synchronize the request/response if needed */
 352         struct completion wait_event;
 353
 354         struct vmbus_channel_packet_multipage_buffer mpb;
 355         struct vmbus_packet_mpb_array *payload;
 356         u32 payload_sz;
 357
 358         struct vstor_packet vstor_packet;
 359 };
 360
 361
 362 /* A storvsc device is a device object that contains a vmbus channel */
 363 struct storvsc_device {
 364         struct hv_device *device;
 365
 366         bool     destroy;
 367         bool     drain_notify;
 368         bool     open_sub_channel;
 369         atomic_t num_outstanding_req;
 370         struct Scsi_Host *host;
 371
 372         wait_queue_head_t waiting_to_drain;
 373
 374         /*
 375          * Each unique Port/Path/Target represents 1 channel ie scsi
 376          * controller. In reality, the pathid, targetid is always 0
 377          * and the port is set by us
 378          */
 379         unsigned int port_number;
 380         unsigned char path_id;
 381         unsigned char target_id;
 382
 383         /*
 384          * Max I/O, the device can support.
 385          */
 386         u32   max_transfer_bytes;
 387         /* Used for vsc/vsp channel reset process */
 388         struct storvsc_cmd_request init_request;
 389         struct storvsc_cmd_request reset_request;
 390 };
 391
 392 struct hv_host_device {
 393         struct hv_device *dev;
 394         unsigned int port;
 395         unsigned char path;
 396         unsigned char target;
 397 };
 398
 399 struct storvsc_scan_work {
 400         struct work_struct work;
 401         struct Scsi_Host *host;
 402         uint lun;
 403 };
 404
 405 static void storvsc_device_scan(struct work_struct *work)
 406 {
 407         struct storvsc_scan_work *wrk;
 408         uint lun;
 409         struct scsi_device *sdev;
 410
 411         wrk = container_of(work, struct storvsc_scan_work, work);
 412         lun = wrk->lun;
 413
 414         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 415         if (!sdev)
 416                 goto done;
 417         scsi_rescan_device(&sdev->sdev_gendev);
 418         scsi_device_put(sdev);
 419
 420 done:
 421         kfree(wrk);
 422 }
 423
 424 static void storvsc_host_scan(struct work_struct *work)
 425 {
 426         struct storvsc_scan_work *wrk;
 427         struct Scsi_Host *host;
 428         struct scsi_device *sdev;
 429
 430         wrk = container_of(work, struct storvsc_scan_work, work);
 431         host = wrk->host;
 432
 433         /*
 434          * Before scanning the host, first check to see if any of the
 435          * currrently known devices have been hot removed. We issue a
 436          * "unit ready" command against all currently known devices.
 437          * This I/O will result in an error for devices that have been
 438          * removed. As part of handling the I/O error, we remove the device.
 439          *
 440          * When a LUN is added or removed, the host sends us a signal to
 441          * scan the host. Thus we are forced to discover the LUNs that
 442          * may have been removed this way.
 443          */
 444         mutex_lock(&host->scan_mutex);
 445         shost_for_each_device(sdev, host)
 446                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 447         mutex_unlock(&host->scan_mutex);
 448         /*
 449          * Now scan the host to discover LUNs that may have been added.
 450          */
 451         scsi_scan_host(host);
 452
 453         kfree(wrk);
 454 }
 455
 456 static void storvsc_remove_lun(struct work_struct *work)
 457 {
 458         struct storvsc_scan_work *wrk;
 459         struct scsi_device *sdev;
 460
 461         wrk = container_of(work, struct storvsc_scan_work, work);
 462         if (!scsi_host_get(wrk->host))
 463                 goto done;
 464
 465         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 466
 467         if (sdev) {
 468                 scsi_remove_device(sdev);
 469                 scsi_device_put(sdev);
 470         }
 471         scsi_host_put(wrk->host);
 472
 473 done:
 474         kfree(wrk);
 475 }
 476
 477 /*
 478  * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 479  * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 480  */
 481
 482 static inline u16 storvsc_get_version(u8 major, u8 minor)
 483 {
 484         u16 version;
 485
 486         version = ((major << 8) | minor);
 487         return version;
 488 }
 489
 490 /*
 491  * We can get incoming messages from the host that are not in response to
 492  * messages that we have sent out. An example of this would be messages
 493  * received by the guest to notify dynamic addition/removal of LUNs. To
 494  * deal with potential race conditions where the driver may be in the
 495  * midst of being unloaded when we might receive an unsolicited message
 496  * from the host, we have implemented a mechanism to gurantee sequential
 497  * consistency:
 498  *
 499  * 1) Once the device is marked as being destroyed, we will fail all
 500  *    outgoing messages.
 501  * 2) We permit incoming messages when the device is being destroyed,
 502  *    only to properly account for messages already sent out.
 503  */
 504
 505 static inline struct storvsc_device *get_out_stor_device(
 506                                         struct hv_device *device)
 507 {
 508         struct storvsc_device *stor_device;
 509
 510         stor_device = hv_get_drvdata(device);
 511
 512         if (stor_device && stor_device->destroy)
 513                 stor_device = NULL;
 514
 515         return stor_device;
 516 }
 517
 518
 519 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 520 {
 521         dev->drain_notify = true;
 522         wait_event(dev->waiting_to_drain,
 523                    atomic_read(&dev->num_outstanding_req) == 0);
 524         dev->drain_notify = false;
 525 }
 526
 527 static inline struct storvsc_device *get_in_stor_device(
 528                                         struct hv_device *device)
 529 {
 530         struct storvsc_device *stor_device;
 531
 532         stor_device = hv_get_drvdata(device);
 533
 534         if (!stor_device)
 535                 goto get_in_err;
 536
 537         /*
 538          * If the device is being destroyed; allow incoming
 539          * traffic only to cleanup outstanding requests.
 540          */
 541
 542         if (stor_device->destroy  &&
 543                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 544                 stor_device = NULL;
 545
 546 get_in_err:
 547         return stor_device;
 548
 549 }
 550
 551 static void destroy_bounce_buffer(struct scatterlist *sgl,
 552                                   unsigned int sg_count)
 553 {
 554         int i;
 555         struct page *page_buf;
 556
 557         for (i = 0; i < sg_count; i++) {
 558                 page_buf = sg_page((&sgl[i]));
 559                 if (page_buf != NULL)
 560                         __free_page(page_buf);
 561         }
 562
 563         kfree(sgl);
 564 }
 565
 566 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 567 {
 568         int i;
 569
 570         /* No need to check */
 571         if (sg_count < 2)
 572                 return -1;
 573
 574         /* We have at least 2 sg entries */
 575         for (i = 0; i < sg_count; i++) {
 576                 if (i == 0) {
 577                         /* make sure 1st one does not have hole */
 578                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 579                                 return i;
 580                 } else if (i == sg_count - 1) {
 581                         /* make sure last one does not have hole */
 582                         if (sgl[i].offset != 0)
 583                                 return i;
 584                 } else {
 585                         /* make sure no hole in the middle */
 586                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 587                                 return i;
 588                 }
 589         }
 590         return -1;
 591 }
 592
 593 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 594                                                 unsigned int sg_count,
 595                                                 unsigned int len,
 596                                                 int write)
 597 {
 598         int i;
 599         int num_pages;
 600         struct scatterlist *bounce_sgl;
 601         struct page *page_buf;
 602         unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 603
 604         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 605
 606         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 607         if (!bounce_sgl)
 608                 return NULL;
 609
 610         sg_init_table(bounce_sgl, num_pages);
 611         for (i = 0; i < num_pages; i++) {
 612                 page_buf = alloc_page(GFP_ATOMIC);
 613                 if (!page_buf)
 614                         goto cleanup;
 615                 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 616         }
 617
 618         return bounce_sgl;
 619
 620 cleanup:
 621         destroy_bounce_buffer(bounce_sgl, num_pages);
 622         return NULL;
 623 }
 624
 625 /* Assume the original sgl has enough room */
 626 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 627                                             struct scatterlist *bounce_sgl,
 628                                             unsigned int orig_sgl_count,
 629                                             unsigned int bounce_sgl_count)
 630 {
 631         int i;
 632         int j = 0;
 633         unsigned long src, dest;
 634         unsigned int srclen, destlen, copylen;
 635         unsigned int total_copied = 0;
 636         unsigned long bounce_addr = 0;
 637         unsigned long dest_addr = 0;
 638         unsigned long flags;
 639         struct scatterlist *cur_dest_sgl;
 640         struct scatterlist *cur_src_sgl;
 641
 642         local_irq_save(flags);
 643         cur_dest_sgl = orig_sgl;
 644         cur_src_sgl = bounce_sgl;
 645         for (i = 0; i < orig_sgl_count; i++) {
 646                 dest_addr = (unsigned long)
 647                                 kmap_atomic(sg_page(cur_dest_sgl)) +
 648                                 cur_dest_sgl->offset;
 649                 dest = dest_addr;
 650                 destlen = cur_dest_sgl->length;
 651
 652                 if (bounce_addr == 0)
 653                         bounce_addr = (unsigned long)kmap_atomic(
 654                                                         sg_page(cur_src_sgl));
 655
 656                 while (destlen) {
 657                         src = bounce_addr + cur_src_sgl->offset;
 658                         srclen = cur_src_sgl->length - cur_src_sgl->offset;
 659
 660                         copylen = min(srclen, destlen);
 661                         memcpy((void *)dest, (void *)src, copylen);
 662
 663                         total_copied += copylen;
 664                         cur_src_sgl->offset += copylen;
 665                         destlen -= copylen;
 666                         dest += copylen;
 667
 668                         if (cur_src_sgl->offset == cur_src_sgl->length) {
 669                                 /* full */
 670                                 kunmap_atomic((void *)bounce_addr);
 671                                 j++;
 672
 673                                 /*
 674                                  * It is possible that the number of elements
 675                                  * in the bounce buffer may not be equal to
 676                                  * the number of elements in the original
 677                                  * scatter list. Handle this correctly.
 678                                  */
 679
 680                                 if (j == bounce_sgl_count) {
 681                                         /*
 682                                          * We are done; cleanup and return.
 683                                          */
 684                                         kunmap_atomic((void *)(dest_addr -
 685                                                 cur_dest_sgl->offset));
 686                                         local_irq_restore(flags);
 687                                         return total_copied;
 688                                 }
 689
 690                                 /* if we need to use another bounce buffer */
 691                                 if (destlen || i != orig_sgl_count - 1) {
 692                                         cur_src_sgl = sg_next(cur_src_sgl);
 693                                         bounce_addr = (unsigned long)
 694                                                         kmap_atomic(
 695                                                         sg_page(cur_src_sgl));
 696                                 }
 697                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 698                                 /* unmap the last bounce that is < PAGE_SIZE */
 699                                 kunmap_atomic((void *)bounce_addr);
 700                         }
 701                 }
 702
 703                 kunmap_atomic((void *)(dest_addr - cur_dest_sgl->offset));
 704                 cur_dest_sgl = sg_next(cur_dest_sgl);
 705         }
 706
 707         local_irq_restore(flags);
 708
 709         return total_copied;
 710 }
 711
 712 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 713 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 714                                           struct scatterlist *bounce_sgl,
 715                                           unsigned int orig_sgl_count)
 716 {
 717         int i;
 718         int j = 0;
 719         unsigned long src, dest;
 720         unsigned int srclen, destlen, copylen;
 721         unsigned int total_copied = 0;
 722         unsigned long bounce_addr = 0;
 723         unsigned long src_addr = 0;
 724         unsigned long flags;
 725         struct scatterlist *cur_src_sgl;
 726         struct scatterlist *cur_dest_sgl;
 727
 728         local_irq_save(flags);
 729
 730         cur_src_sgl = orig_sgl;
 731         cur_dest_sgl = bounce_sgl;
 732
 733         for (i = 0; i < orig_sgl_count; i++) {
 734                 src_addr = (unsigned long)
 735                                 kmap_atomic(sg_page(cur_src_sgl)) +
 736                                 cur_src_sgl->offset;
 737                 src = src_addr;
 738                 srclen = cur_src_sgl->length;
 739
 740                 if (bounce_addr == 0)
 741                         bounce_addr = (unsigned long)
 742                                         kmap_atomic(sg_page(cur_dest_sgl));
 743
 744                 while (srclen) {
 745                         /* assume bounce offset always == 0 */
 746                         dest = bounce_addr + cur_dest_sgl->length;
 747                         destlen = PAGE_SIZE - cur_dest_sgl->length;
 748
 749                         copylen = min(srclen, destlen);
 750                         memcpy((void *)dest, (void *)src, copylen);
 751
 752                         total_copied += copylen;
 753                         cur_dest_sgl->length += copylen;
 754                         srclen -= copylen;
 755                         src += copylen;
 756
 757                         if (cur_dest_sgl->length == PAGE_SIZE) {
 758                                 /* full..move to next entry */
 759                                 kunmap_atomic((void *)bounce_addr);
 760                                 bounce_addr = 0;
 761                                 j++;
 762                         }
 763
 764                         /* if we need to use another bounce buffer */
 765                         if (srclen && bounce_addr == 0) {
 766                                 cur_dest_sgl = sg_next(cur_dest_sgl);
 767                                 bounce_addr = (unsigned long)
 768                                                 kmap_atomic(
 769                                                 sg_page(cur_dest_sgl));
 770                         }
 771
 772                 }
 773
 774                 kunmap_atomic((void *)(src_addr - cur_src_sgl->offset));
 775                 cur_src_sgl = sg_next(cur_src_sgl);
 776         }
 777
 778         if (bounce_addr)
 779                 kunmap_atomic((void *)bounce_addr);
 780
 781         local_irq_restore(flags);
 782
 783         return total_copied;
 784 }
 785
 786 static void handle_sc_creation(struct vmbus_channel *new_sc)
 787 {
 788         struct hv_device *device = new_sc->primary_channel->device_obj;
 789         struct storvsc_device *stor_device;
 790         struct vmstorage_channel_properties props;
 791
 792         stor_device = get_out_stor_device(device);
 793         if (!stor_device)
 794                 return;
 795
 796         if (stor_device->open_sub_channel == false)
 797                 return;
 798
 799         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 800
 801         vmbus_open(new_sc,
 802                    storvsc_ringbuffer_size,
 803                    storvsc_ringbuffer_size,
 804                    (void *)&props,
 805                    sizeof(struct vmstorage_channel_properties),
 806                    storvsc_on_channel_callback, new_sc);
 807 }
 808
 809 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 810 {
 811         struct storvsc_device *stor_device;
 812         int num_cpus = num_online_cpus();
 813         int num_sc;
 814         struct storvsc_cmd_request *request;
 815         struct vstor_packet *vstor_packet;
 816         int ret, t;
 817
 818         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 819         stor_device = get_out_stor_device(device);
 820         if (!stor_device)
 821                 return;
 822
 823         request = &stor_device->init_request;
 824         vstor_packet = &request->vstor_packet;
 825
 826         stor_device->open_sub_channel = true;
 827         /*
 828          * Establish a handler for dealing with subchannels.
 829          */
 830         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 831
 832         /*
 833          * Check to see if sub-channels have already been created. This
 834          * can happen when this driver is re-loaded after unloading.
 835          */
 836
 837         if (vmbus_are_subchannels_present(device->channel))
 838                 return;
 839
 840         stor_device->open_sub_channel = false;
 841         /*
 842          * Request the host to create sub-channels.
 843          */
 844         memset(request, 0, sizeof(struct storvsc_cmd_request));
 845         init_completion(&request->wait_event);
 846         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 847         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 848         vstor_packet->sub_channel_count = num_sc;
 849
 850         ret = vmbus_sendpacket(device->channel, vstor_packet,
 851                                (sizeof(struct vstor_packet) -
 852                                vmscsi_size_delta),
 853                                (unsigned long)request,
 854                                VM_PKT_DATA_INBAND,
 855                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 856
 857         if (ret != 0)
 858                 return;
 859
 860         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 861         if (t == 0)
 862                 return;
 863
 864         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 865             vstor_packet->status != 0)
 866                 return;
 867
 868         /*
 869          * Now that we created the sub-channels, invoke the check; this
 870          * may trigger the callback.
 871          */
 872         stor_device->open_sub_channel = true;
 873         vmbus_are_subchannels_present(device->channel);
 874 }
 875
 876 static int storvsc_channel_init(struct hv_device *device)
 877 {
 878         struct storvsc_device *stor_device;
 879         struct storvsc_cmd_request *request;
 880         struct vstor_packet *vstor_packet;
 881         int ret, t;
 882         int max_chns;
 883         bool process_sub_channels = false;
 884
 885         stor_device = get_out_stor_device(device);
 886         if (!stor_device)
 887                 return -ENODEV;
 888
 889         request = &stor_device->init_request;
 890         vstor_packet = &request->vstor_packet;
 891
 892         /*
 893          * Now, initiate the vsc/vsp initialization protocol on the open
 894          * channel
 895          */
 896         memset(request, 0, sizeof(struct storvsc_cmd_request));
 897         init_completion(&request->wait_event);
 898         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 899         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 900
 901         ret = vmbus_sendpacket(device->channel, vstor_packet,
 902                                (sizeof(struct vstor_packet) -
 903                                vmscsi_size_delta),
 904                                (unsigned long)request,
 905                                VM_PKT_DATA_INBAND,
 906                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 907         if (ret != 0)
 908                 goto cleanup;
 909
 910         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 911         if (t == 0) {
 912                 ret = -ETIMEDOUT;
 913                 goto cleanup;
 914         }
 915
 916         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 917             vstor_packet->status != 0)
 918                 goto cleanup;
 919
 920
 921         /* reuse the packet for version range supported */
 922         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 923         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 924         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 925
 926         vstor_packet->version.major_minor =
 927                 storvsc_get_version(vmstor_current_major, vmstor_current_minor);
 928
 929         /*
 930          * The revision number is only used in Windows; set it to 0.
 931          */
 932         vstor_packet->version.revision = 0;
 933
 934         ret = vmbus_sendpacket(device->channel, vstor_packet,
 935                                (sizeof(struct vstor_packet) -
 936                                 vmscsi_size_delta),
 937                                (unsigned long)request,
 938                                VM_PKT_DATA_INBAND,
 939                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 940         if (ret != 0)
 941                 goto cleanup;
 942
 943         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 944         if (t == 0) {
 945                 ret = -ETIMEDOUT;
 946                 goto cleanup;
 947         }
 948
 949         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 950             vstor_packet->status != 0)
 951                 goto cleanup;
 952
 953
 954         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 955         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 956         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 957
 958         ret = vmbus_sendpacket(device->channel, vstor_packet,
 959                                (sizeof(struct vstor_packet) -
 960                                 vmscsi_size_delta),
 961                                (unsigned long)request,
 962                                VM_PKT_DATA_INBAND,
 963                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 964
 965         if (ret != 0)
 966                 goto cleanup;
 967
 968         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 969         if (t == 0) {
 970                 ret = -ETIMEDOUT;
 971                 goto cleanup;
 972         }
 973
 974         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 975             vstor_packet->status != 0)
 976                 goto cleanup;
 977
 978         /*
 979          * Check to see if multi-channel support is there.
 980          * Hosts that implement protocol version of 5.1 and above
 981          * support multi-channel.
 982          */
 983         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 984         if (vmbus_proto_version >= VERSION_WIN8) {
 985                 if (vstor_packet->storage_channel_properties.flags &
 986                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 987                         process_sub_channels = true;
 988         }
 989         stor_device->max_transfer_bytes =
 990                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 991
 992         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 993         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 994         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 995
 996         ret = vmbus_sendpacket(device->channel, vstor_packet,
 997                                (sizeof(struct vstor_packet) -
 998                                 vmscsi_size_delta),
 999                                (unsigned long)request,
1000                                VM_PKT_DATA_INBAND,
1001                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1002
1003         if (ret != 0)
1004                 goto cleanup;
1005
1006         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1007         if (t == 0) {
1008                 ret = -ETIMEDOUT;
1009                 goto cleanup;
1010         }
1011
1012         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
1013             vstor_packet->status != 0)
1014                 goto cleanup;
1015
1016         if (process_sub_channels)
1017                 handle_multichannel_storage(device, max_chns);
1018
1019
1020 cleanup:
1021         return ret;
1022 }
1023
1024 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1025                                 struct scsi_cmnd *scmnd,
1026                                 struct Scsi_Host *host,
1027                                 u8 asc, u8 ascq)
1028 {
1029         struct storvsc_scan_work *wrk;
1030         void (*process_err_fn)(struct work_struct *work);
1031         bool do_work = false;
1032
1033         switch (vm_srb->srb_status) {
1034         case SRB_STATUS_ERROR:
1035                 /*
1036                  * If there is an error; offline the device since all
1037                  * error recovery strategies would have already been
1038                  * deployed on the host side. However, if the command
1039                  * were a pass-through command deal with it appropriately.
1040                  */
1041                 switch (scmnd->cmnd[0]) {
1042                 case ATA_16:
1043                 case ATA_12:
1044                         set_host_byte(scmnd, DID_PASSTHROUGH);
1045                         break;
1046                 /*
1047                  * On Some Windows hosts TEST_UNIT_READY command can return
1048                  * SRB_STATUS_ERROR, let the upper level code deal with it
1049                  * based on the sense information.
1050                  */
1051                 case TEST_UNIT_READY:
1052                         break;
1053                 default:
1054                         set_host_byte(scmnd, DID_TARGET_FAILURE);
1055                 }
1056                 break;
1057         case SRB_STATUS_INVALID_LUN:
1058                 do_work = true;
1059                 process_err_fn = storvsc_remove_lun;
1060                 break;
1061         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
1062                 if ((asc == 0x2a) && (ascq == 0x9)) {
1063                         do_work = true;
1064                         process_err_fn = storvsc_device_scan;
1065                         /*
1066                          * Retry the I/O that trigerred this.
1067                          */
1068                         set_host_byte(scmnd, DID_REQUEUE);
1069                 }
1070                 break;
1071         }
1072
1073         if (!do_work)
1074                 return;
1075
1076         /*
1077          * We need to schedule work to process this error; schedule it.
1078          */
1079         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1080         if (!wrk) {
1081                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1082                 return;
1083         }
1084
1085         wrk->host = host;
1086         wrk->lun = vm_srb->lun;
1087         INIT_WORK(&wrk->work, process_err_fn);
1088         schedule_work(&wrk->work);
1089 }
1090
1091
1092 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
1093 {
1094         struct scsi_cmnd *scmnd = cmd_request->cmd;
1095         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1096         struct scsi_sense_hdr sense_hdr;
1097         struct vmscsi_request *vm_srb;
1098         struct Scsi_Host *host;
1099         struct storvsc_device *stor_dev;
1100         struct hv_device *dev = host_dev->dev;
1101         u32 payload_sz = cmd_request->payload_sz;
1102         void *payload = cmd_request->payload;
1103
1104         stor_dev = get_in_stor_device(dev);
1105         host = stor_dev->host;
1106
1107         vm_srb = &cmd_request->vstor_packet.vm_srb;
1108         if (cmd_request->bounce_sgl_count) {
1109                 if (vm_srb->data_in == READ_TYPE)
1110                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1111                                         cmd_request->bounce_sgl,
1112                                         scsi_sg_count(scmnd),
1113                                         cmd_request->bounce_sgl_count);
1114                 destroy_bounce_buffer(cmd_request->bounce_sgl,
1115                                         cmd_request->bounce_sgl_count);
1116         }
1117
1118         scmnd->result = vm_srb->scsi_status;
1119
1120         if (scmnd->result) {
1121                 if (scsi_normalize_sense(scmnd->sense_buffer,
1122                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1123                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1124                                              &sense_hdr);
1125         }
1126
1127         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
1128                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1129                                          sense_hdr.ascq);
1130
1131         scsi_set_resid(scmnd,
1132                 cmd_request->payload->range.len -
1133                 vm_srb->data_transfer_length);
1134
1135         scmnd->scsi_done(scmnd);
1136
1137         if (payload_sz >
1138                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1139                 kfree(payload);
1140 }
1141
1142 static void storvsc_on_io_completion(struct hv_device *device,
1143                                   struct vstor_packet *vstor_packet,
1144                                   struct storvsc_cmd_request *request)
1145 {
1146         struct storvsc_device *stor_device;
1147         struct vstor_packet *stor_pkt;
1148
1149         stor_device = hv_get_drvdata(device);
1150         stor_pkt = &request->vstor_packet;
1151
1152         /*
1153          * The current SCSI handling on the host side does
1154          * not correctly handle:
1155          * INQUIRY command with page code parameter set to 0x80
1156          * MODE_SENSE command with cmd[2] == 0x1c
1157          *
1158          * Setup srb and scsi status so this won't be fatal.
1159          * We do this so we can distinguish truly fatal failues
1160          * (srb status == 0x4) and off-line the device in that case.
1161          */
1162
1163         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1164            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1165                 vstor_packet->vm_srb.scsi_status = 0;
1166                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1167         }
1168
1169
1170         /* Copy over the status...etc */
1171         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1172         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1173         stor_pkt->vm_srb.sense_info_length =
1174         vstor_packet->vm_srb.sense_info_length;
1175
1176
1177         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1178                 /* CHECK_CONDITION */
1179                 if (vstor_packet->vm_srb.srb_status &
1180                         SRB_STATUS_AUTOSENSE_VALID) {
1181                         /* autosense data available */
1182
1183                         memcpy(request->cmd->sense_buffer,
1184                                vstor_packet->vm_srb.sense_data,
1185                                vstor_packet->vm_srb.sense_info_length);
1186
1187                 }
1188         }
1189
1190         stor_pkt->vm_srb.data_transfer_length =
1191         vstor_packet->vm_srb.data_transfer_length;
1192
1193         storvsc_command_completion(request);
1194
1195         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1196                 stor_device->drain_notify)
1197                 wake_up(&stor_device->waiting_to_drain);
1198
1199
1200 }
1201
1202 static void storvsc_on_receive(struct hv_device *device,
1203                              struct vstor_packet *vstor_packet,
1204                              struct storvsc_cmd_request *request)
1205 {
1206         struct storvsc_scan_work *work;
1207         struct storvsc_device *stor_device;
1208
1209         switch (vstor_packet->operation) {
1210         case VSTOR_OPERATION_COMPLETE_IO:
1211                 storvsc_on_io_completion(device, vstor_packet, request);
1212                 break;
1213
1214         case VSTOR_OPERATION_REMOVE_DEVICE:
1215         case VSTOR_OPERATION_ENUMERATE_BUS:
1216                 stor_device = get_in_stor_device(device);
1217                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1218                 if (!work)
1219                         return;
1220
1221                 INIT_WORK(&work->work, storvsc_host_scan);
1222                 work->host = stor_device->host;
1223                 schedule_work(&work->work);
1224                 break;
1225
1226         default:
1227                 break;
1228         }
1229 }
1230
1231 static void storvsc_on_channel_callback(void *context)
1232 {
1233         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1234         struct hv_device *device;
1235         struct storvsc_device *stor_device;
1236         u32 bytes_recvd;
1237         u64 request_id;
1238         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1239         struct storvsc_cmd_request *request;
1240         int ret;
1241
1242         if (channel->primary_channel != NULL)
1243                 device = channel->primary_channel->device_obj;
1244         else
1245                 device = channel->device_obj;
1246
1247         stor_device = get_in_stor_device(device);
1248         if (!stor_device)
1249                 return;
1250
1251         do {
1252                 ret = vmbus_recvpacket(channel, packet,
1253                                        ALIGN((sizeof(struct vstor_packet) -
1254                                              vmscsi_size_delta), 8),
1255                                        &bytes_recvd, &request_id);
1256                 if (ret == 0 && bytes_recvd > 0) {
1257
1258                         request = (struct storvsc_cmd_request *)
1259                                         (unsigned long)request_id;
1260
1261                         if ((request == &stor_device->init_request) ||
1262                             (request == &stor_device->reset_request)) {
1263
1264                                 memcpy(&request->vstor_packet, packet,
1265                                        (sizeof(struct vstor_packet) -
1266                                         vmscsi_size_delta));
1267                                 complete(&request->wait_event);
1268                         } else {
1269                                 storvsc_on_receive(device,
1270                                                 (struct vstor_packet *)packet,
1271                                                 request);
1272                         }
1273                 } else {
1274                         break;
1275                 }
1276         } while (1);
1277
1278         return;
1279 }
1280
1281 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1282 {
1283         struct vmstorage_channel_properties props;
1284         int ret;
1285
1286         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1287
1288         ret = vmbus_open(device->channel,
1289                          ring_size,
1290                          ring_size,
1291                          (void *)&props,
1292                          sizeof(struct vmstorage_channel_properties),
1293                          storvsc_on_channel_callback, device->channel);
1294
1295         if (ret != 0)
1296                 return ret;
1297
1298         ret = storvsc_channel_init(device);
1299
1300         return ret;
1301 }
1302
1303 static int storvsc_dev_remove(struct hv_device *device)
1304 {
1305         struct storvsc_device *stor_device;
1306         unsigned long flags;
1307
1308         stor_device = hv_get_drvdata(device);
1309
1310         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1311         stor_device->destroy = true;
1312         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1313
1314         /*
1315          * At this point, all outbound traffic should be disable. We
1316          * only allow inbound traffic (responses) to proceed so that
1317          * outstanding requests can be completed.
1318          */
1319
1320         storvsc_wait_to_drain(stor_device);
1321
1322         /*
1323          * Since we have already drained, we don't need to busy wait
1324          * as was done in final_release_stor_device()
1325          * Note that we cannot set the ext pointer to NULL until
1326          * we have drained - to drain the outgoing packets, we need to
1327          * allow incoming packets.
1328          */
1329         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1330         hv_set_drvdata(device, NULL);
1331         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1332
1333         /* Close the channel */
1334         vmbus_close(device->channel);
1335
1336         kfree(stor_device);
1337         return 0;
1338 }
1339
1340 static int storvsc_do_io(struct hv_device *device,
1341                          struct storvsc_cmd_request *request)
1342 {
1343         struct storvsc_device *stor_device;
1344         struct vstor_packet *vstor_packet;
1345         struct vmbus_channel *outgoing_channel;
1346         int ret = 0;
1347
1348         vstor_packet = &request->vstor_packet;
1349         stor_device = get_out_stor_device(device);
1350
1351         if (!stor_device)
1352                 return -ENODEV;
1353
1354
1355         request->device  = device;
1356         /*
1357          * Select an an appropriate channel to send the request out.
1358          */
1359
1360         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1361
1362
1363         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1364
1365         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1366                                         vmscsi_size_delta);
1367
1368
1369         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1370
1371
1372         vstor_packet->vm_srb.data_transfer_length =
1373         request->payload->range.len;
1374
1375         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1376
1377         if (request->payload->range.len) {
1378
1379                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1380                                 request->payload, request->payload_sz,
1381                                 vstor_packet,
1382                                 (sizeof(struct vstor_packet) -
1383                                 vmscsi_size_delta),
1384                                 (unsigned long)request);
1385         } else {
1386                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1387                                (sizeof(struct vstor_packet) -
1388                                 vmscsi_size_delta),
1389                                (unsigned long)request,
1390                                VM_PKT_DATA_INBAND,
1391                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1392         }
1393
1394         if (ret != 0)
1395                 return ret;
1396
1397         atomic_inc(&stor_device->num_outstanding_req);
1398
1399         return ret;
1400 }
1401
1402 static int storvsc_device_configure(struct scsi_device *sdevice)
1403 {
1404
1405         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1406
1407         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1408
1409         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1410
1411         sdevice->no_write_same = 1;
1412
1413         /*
1414          * Add blist flags to permit the reading of the VPD pages even when
1415          * the target may claim SPC-2 compliance. MSFT targets currently
1416          * claim SPC-2 compliance while they implement post SPC-2 features.
1417          * With this patch we can correctly handle WRITE_SAME_16 issues.
1418          */
1419         sdevice->sdev_bflags |= msft_blist_flags;
1420
1421         /*
1422          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1423          * if the device is a MSFT virtual device.
1424          */
1425         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1426                 switch (vmbus_proto_version) {
1427                 case VERSION_WIN8:
1428                 case VERSION_WIN8_1:
1429                         sdevice->scsi_level = SCSI_SPC_3;
1430                         break;
1431                 }
1432         }
1433
1434         return 0;
1435 }
1436
1437 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1438                            sector_t capacity, int *info)
1439 {
1440         sector_t nsect = capacity;
1441         sector_t cylinders = nsect;
1442         int heads, sectors_pt;
1443
1444         /*
1445          * We are making up these values; let us keep it simple.
1446          */
1447         heads = 0xff;
1448         sectors_pt = 0x3f;      /* Sectors per track */
1449         sector_div(cylinders, heads * sectors_pt);
1450         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1451                 cylinders = 0xffff;
1452
1453         info[0] = heads;
1454         info[1] = sectors_pt;
1455         info[2] = (int)cylinders;
1456
1457         return 0;
1458 }
1459
1460 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1461 {
1462         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1463         struct hv_device *device = host_dev->dev;
1464
1465         struct storvsc_device *stor_device;
1466         struct storvsc_cmd_request *request;
1467         struct vstor_packet *vstor_packet;
1468         int ret, t;
1469
1470
1471         stor_device = get_out_stor_device(device);
1472         if (!stor_device)
1473                 return FAILED;
1474
1475         request = &stor_device->reset_request;
1476         vstor_packet = &request->vstor_packet;
1477
1478         init_completion(&request->wait_event);
1479
1480         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1481         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1482         vstor_packet->vm_srb.path_id = stor_device->path_id;
1483
1484         ret = vmbus_sendpacket(device->channel, vstor_packet,
1485                                (sizeof(struct vstor_packet) -
1486                                 vmscsi_size_delta),
1487                                (unsigned long)&stor_device->reset_request,
1488                                VM_PKT_DATA_INBAND,
1489                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1490         if (ret != 0)
1491                 return FAILED;
1492
1493         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1494         if (t == 0)
1495                 return TIMEOUT_ERROR;
1496
1497
1498         /*
1499          * At this point, all outstanding requests in the adapter
1500          * should have been flushed out and return to us
1501          * There is a potential race here where the host may be in
1502          * the process of responding when we return from here.
1503          * Just wait for all in-transit packets to be accounted for
1504          * before we return from here.
1505          */
1506         storvsc_wait_to_drain(stor_device);
1507
1508         return SUCCESS;
1509 }
1510
1511 /*
1512  * The host guarantees to respond to each command, although I/O latencies might
1513  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1514  * chance to perform EH.
1515  */
1516 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1517 {
1518         return BLK_EH_RESET_TIMER;
1519 }
1520
1521 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1522 {
1523         bool allowed = true;
1524         u8 scsi_op = scmnd->cmnd[0];
1525
1526         switch (scsi_op) {
1527         /* the host does not handle WRITE_SAME, log accident usage */
1528         case WRITE_SAME:
1529         /*
1530          * smartd sends this command and the host does not handle
1531          * this. So, don't send it.
1532          */
1533         case SET_WINDOW:
1534                 scmnd->result = ILLEGAL_REQUEST << 16;
1535                 allowed = false;
1536                 break;
1537         default:
1538                 break;
1539         }
1540         return allowed;
1541 }
1542
1543 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1544 {
1545         int ret;
1546         struct hv_host_device *host_dev = shost_priv(host);
1547         struct hv_device *dev = host_dev->dev;
1548         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1549         int i;
1550         struct scatterlist *sgl;
1551         unsigned int sg_count = 0;
1552         struct vmscsi_request *vm_srb;
1553         struct scatterlist *cur_sgl;
1554         struct vmbus_packet_mpb_array  *payload;
1555         u32 payload_sz;
1556         u32 length;
1557
1558         if (vmstor_current_major <= VMSTOR_WIN8_MAJOR) {
1559                 /*
1560                  * On legacy hosts filter unimplemented commands.
1561                  * Future hosts are expected to correctly handle
1562                  * unsupported commands. Furthermore, it is
1563                  * possible that some of the currently
1564                  * unsupported commands maybe supported in
1565                  * future versions of the host.
1566                  */
1567                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1568                         scmnd->scsi_done(scmnd);
1569                         return 0;
1570                 }
1571         }
1572
1573         /* Setup the cmd request */
1574         cmd_request->cmd = scmnd;
1575
1576         vm_srb = &cmd_request->vstor_packet.vm_srb;
1577         vm_srb->win8_extension.time_out_value = 60;
1578
1579         vm_srb->win8_extension.srb_flags |=
1580                 (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1581                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1582
1583         /* Build the SRB */
1584         switch (scmnd->sc_data_direction) {
1585         case DMA_TO_DEVICE:
1586                 vm_srb->data_in = WRITE_TYPE;
1587                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1588                 break;
1589         case DMA_FROM_DEVICE:
1590                 vm_srb->data_in = READ_TYPE;
1591                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1592                 break;
1593         case DMA_NONE:
1594                 vm_srb->data_in = UNKNOWN_TYPE;
1595                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1596                 break;
1597         default:
1598                 /*
1599                  * This is DMA_BIDIRECTIONAL or something else we are never
1600                  * supposed to see here.
1601                  */
1602                 WARN(1, "Unexpected data direction: %d\n",
1603                      scmnd->sc_data_direction);
1604                 return -EINVAL;
1605         }
1606
1607
1608         vm_srb->port_number = host_dev->port;
1609         vm_srb->path_id = scmnd->device->channel;
1610         vm_srb->target_id = scmnd->device->id;
1611         vm_srb->lun = scmnd->device->lun;
1612
1613         vm_srb->cdb_length = scmnd->cmd_len;
1614
1615         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1616
1617         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1618         sg_count = scsi_sg_count(scmnd);
1619
1620         length = scsi_bufflen(scmnd);
1621         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1622         payload_sz = sizeof(cmd_request->mpb);
1623
1624         if (sg_count) {
1625                 /* check if we need to bounce the sgl */
1626                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1627                         cmd_request->bounce_sgl =
1628                                 create_bounce_buffer(sgl, sg_count,
1629                                                      length,
1630                                                      vm_srb->data_in);
1631                         if (!cmd_request->bounce_sgl)
1632                                 return SCSI_MLQUEUE_HOST_BUSY;
1633
1634                         cmd_request->bounce_sgl_count =
1635                                 ALIGN(length, PAGE_SIZE) >> PAGE_SHIFT;
1636
1637                         if (vm_srb->data_in == WRITE_TYPE)
1638                                 copy_to_bounce_buffer(sgl,
1639                                         cmd_request->bounce_sgl, sg_count);
1640
1641                         sgl = cmd_request->bounce_sgl;
1642                         sg_count = cmd_request->bounce_sgl_count;
1643                 }
1644
1645
1646                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1647
1648                         payload_sz = (sg_count * sizeof(void *) +
1649                                       sizeof(struct vmbus_packet_mpb_array));
1650                         payload = kmalloc(payload_sz, GFP_ATOMIC);
1651                         if (!payload) {
1652                                 if (cmd_request->bounce_sgl_count)
1653                                         destroy_bounce_buffer(
1654                                         cmd_request->bounce_sgl,
1655                                         cmd_request->bounce_sgl_count);
1656
1657                                         return SCSI_MLQUEUE_DEVICE_BUSY;
1658                         }
1659                 }
1660
1661                 payload->range.len = length;
1662                 payload->range.offset = sgl[0].offset;
1663
1664                 cur_sgl = sgl;
1665                 for (i = 0; i < sg_count; i++) {
1666                         payload->range.pfn_array[i] =
1667                                 page_to_pfn(sg_page((cur_sgl)));
1668                         cur_sgl = sg_next(cur_sgl);
1669                 }
1670
1671         } else if (scsi_sglist(scmnd)) {
1672                 payload->range.len = length;
1673                 payload->range.offset =
1674                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1675                 payload->range.pfn_array[0] =
1676                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1677         }
1678
1679         cmd_request->payload = payload;
1680         cmd_request->payload_sz = payload_sz;
1681
1682         /* Invokes the vsc to start an IO */
1683         ret = storvsc_do_io(dev, cmd_request);
1684
1685         if (ret == -EAGAIN) {
1686                 /* no more space */
1687
1688                 if (cmd_request->bounce_sgl_count)
1689                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1690                                         cmd_request->bounce_sgl_count);
1691
1692                 return SCSI_MLQUEUE_DEVICE_BUSY;
1693         }
1694
1695         return 0;
1696 }
1697
1698 static struct scsi_host_template scsi_driver = {
1699         .module =               THIS_MODULE,
1700         .name =                 "storvsc_host_t",
1701         .cmd_size =             sizeof(struct storvsc_cmd_request),
1702         .bios_param =           storvsc_get_chs,
1703         .queuecommand =         storvsc_queuecommand,
1704         .eh_host_reset_handler =        storvsc_host_reset_handler,
1705         .proc_name =            "storvsc_host",
1706         .eh_timed_out =         storvsc_eh_timed_out,
1707         .slave_configure =      storvsc_device_configure,
1708         .cmd_per_lun =          255,
1709         .this_id =              -1,
1710         .use_clustering =       ENABLE_CLUSTERING,
1711         /* Make sure we dont get a sg segment crosses a page boundary */
1712         .dma_boundary =         PAGE_SIZE-1,
1713         .no_write_same =        1,
1714 };
1715
1716 enum {
1717         SCSI_GUID,
1718         IDE_GUID,
1719         SFC_GUID,
1720 };
1721
1722 static const struct hv_vmbus_device_id id_table[] = {
1723         /* SCSI guid */
1724         { HV_SCSI_GUID,
1725           .driver_data = SCSI_GUID
1726         },
1727         /* IDE guid */
1728         { HV_IDE_GUID,
1729           .driver_data = IDE_GUID
1730         },
1731         /* Fibre Channel GUID */
1732         {
1733           HV_SYNTHFC_GUID,
1734           .driver_data = SFC_GUID
1735         },
1736         { },
1737 };
1738
1739 MODULE_DEVICE_TABLE(vmbus, id_table);
1740
1741 static int storvsc_probe(struct hv_device *device,
1742                         const struct hv_vmbus_device_id *dev_id)
1743 {
1744         int ret;
1745         int num_cpus = num_online_cpus();
1746         struct Scsi_Host *host;
1747         struct hv_host_device *host_dev;
1748         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1749         int target = 0;
1750         struct storvsc_device *stor_device;
1751         int max_luns_per_target;
1752         int max_targets;
1753         int max_channels;
1754         int max_sub_channels = 0;
1755
1756         /*
1757          * Based on the windows host we are running on,
1758          * set state to properly communicate with the host.
1759          */
1760
1761         if (vmbus_proto_version < VERSION_WIN8) {
1762                 sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
1763                 vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1764                 vmstor_current_major = VMSTOR_WIN7_MAJOR;
1765                 vmstor_current_minor = VMSTOR_WIN7_MINOR;
1766                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1767                 max_targets = STORVSC_IDE_MAX_TARGETS;
1768                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1769         } else {
1770                 sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
1771                 vmscsi_size_delta = 0;
1772                 vmstor_current_major = VMSTOR_WIN8_MAJOR;
1773                 vmstor_current_minor = VMSTOR_WIN8_MINOR;
1774                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1775                 max_targets = STORVSC_MAX_TARGETS;
1776                 max_channels = STORVSC_MAX_CHANNELS;
1777                 /*
1778                  * On Windows8 and above, we support sub-channels for storage.
1779                  * The number of sub-channels offerred is based on the number of
1780                  * VCPUs in the guest.
1781                  */
1782                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1783         }
1784
1785         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1786                                  (max_sub_channels + 1));
1787
1788         host = scsi_host_alloc(&scsi_driver,
1789                                sizeof(struct hv_host_device));
1790         if (!host)
1791                 return -ENOMEM;
1792
1793         host_dev = shost_priv(host);
1794         memset(host_dev, 0, sizeof(struct hv_host_device));
1795
1796         host_dev->port = host->host_no;
1797         host_dev->dev = device;
1798
1799
1800         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1801         if (!stor_device) {
1802                 ret = -ENOMEM;
1803                 goto err_out0;
1804         }
1805
1806         stor_device->destroy = false;
1807         stor_device->open_sub_channel = false;
1808         init_waitqueue_head(&stor_device->waiting_to_drain);
1809         stor_device->device = device;
1810         stor_device->host = host;
1811         hv_set_drvdata(device, stor_device);
1812
1813         stor_device->port_number = host->host_no;
1814         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1815         if (ret)
1816                 goto err_out1;
1817
1818         host_dev->path = stor_device->path_id;
1819         host_dev->target = stor_device->target_id;
1820
1821         switch (dev_id->driver_data) {
1822         case SFC_GUID:
1823                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1824                 host->max_id = STORVSC_FC_MAX_TARGETS;
1825                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1826                 break;
1827
1828         case SCSI_GUID:
1829                 host->max_lun = max_luns_per_target;
1830                 host->max_id = max_targets;
1831                 host->max_channel = max_channels - 1;
1832                 break;
1833
1834         default:
1835                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1836                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1837                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1838                 break;
1839         }
1840         /* max cmd length */
1841         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1842
1843         /*
1844          * set the table size based on the info we got
1845          * from the host.
1846          */
1847         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1848
1849         /* Register the HBA and start the scsi bus scan */
1850         ret = scsi_add_host(host, &device->device);
1851         if (ret != 0)
1852                 goto err_out2;
1853
1854         if (!dev_is_ide) {
1855                 scsi_scan_host(host);
1856         } else {
1857                 target = (device->dev_instance.b[5] << 8 |
1858                          device->dev_instance.b[4]);
1859                 ret = scsi_add_device(host, 0, target, 0);
1860                 if (ret) {
1861                         scsi_remove_host(host);
1862                         goto err_out2;
1863                 }
1864         }
1865         return 0;
1866
1867 err_out2:
1868         /*
1869          * Once we have connected with the host, we would need to
1870          * to invoke storvsc_dev_remove() to rollback this state and
1871          * this call also frees up the stor_device; hence the jump around
1872          * err_out1 label.
1873          */
1874         storvsc_dev_remove(device);
1875         goto err_out0;
1876
1877 err_out1:
1878         kfree(stor_device);
1879
1880 err_out0:
1881         scsi_host_put(host);
1882         return ret;
1883 }
1884
1885 static int storvsc_remove(struct hv_device *dev)
1886 {
1887         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1888         struct Scsi_Host *host = stor_device->host;
1889
1890         scsi_remove_host(host);
1891         storvsc_dev_remove(dev);
1892         scsi_host_put(host);
1893
1894         return 0;
1895 }
1896
1897 static struct hv_driver storvsc_drv = {
1898         .name = KBUILD_MODNAME,
1899         .id_table = id_table,
1900         .probe = storvsc_probe,
1901         .remove = storvsc_remove,
1902 };
1903
1904 static int __init storvsc_drv_init(void)
1905 {
1906
1907         /*
1908          * Divide the ring buffer data size (which is 1 page less
1909          * than the ring buffer size since that page is reserved for
1910          * the ring buffer indices) by the max request size (which is
1911          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1912          */
1913         max_outstanding_req_per_channel =
1914                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1915                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1916                 sizeof(struct vstor_packet) + sizeof(u64) -
1917                 vmscsi_size_delta,
1918                 sizeof(u64)));
1919
1920         return vmbus_driver_register(&storvsc_drv);
1921 }
1922
1923 static void __exit storvsc_drv_exit(void)
1924 {
1925         vmbus_driver_unregister(&storvsc_drv);
1926 }
1927
1928 MODULE_LICENSE("GPL");
1929 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1930 module_init(storvsc_drv_init);
1931 module_exit(storvsc_drv_exit);