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 = (20 * PAGE_SIZE);
 312
 313 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 314 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 315
 316 /*
 317  * Timeout in seconds for all devices managed by this driver.
 318  */
 319 static int storvsc_timeout = 180;
 320
 321 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
 322
 323 #define STORVSC_MAX_IO_REQUESTS                         200
 324
 325 static void storvsc_on_channel_callback(void *context);
 326
 327 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 328 #define STORVSC_MAX_TARGETS                             2
 329 #define STORVSC_MAX_CHANNELS                            8
 330
 331 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 332 #define STORVSC_FC_MAX_TARGETS                          128
 333 #define STORVSC_FC_MAX_CHANNELS                         8
 334
 335 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 336 #define STORVSC_IDE_MAX_TARGETS                         1
 337 #define STORVSC_IDE_MAX_CHANNELS                        1
 338
 339 struct storvsc_cmd_request {
 340         struct scsi_cmnd *cmd;
 341
 342         unsigned int bounce_sgl_count;
 343         struct scatterlist *bounce_sgl;
 344
 345         struct hv_device *device;
 346
 347         /* Synchronize the request/response if needed */
 348         struct completion wait_event;
 349
 350         struct hv_multipage_buffer data_buffer;
 351         struct vstor_packet vstor_packet;
 352 };
 353
 354
 355 /* A storvsc device is a device object that contains a vmbus channel */
 356 struct storvsc_device {
 357         struct hv_device *device;
 358
 359         bool     destroy;
 360         bool     drain_notify;
 361         bool     open_sub_channel;
 362         atomic_t num_outstanding_req;
 363         struct Scsi_Host *host;
 364
 365         wait_queue_head_t waiting_to_drain;
 366
 367         /*
 368          * Each unique Port/Path/Target represents 1 channel ie scsi
 369          * controller. In reality, the pathid, targetid is always 0
 370          * and the port is set by us
 371          */
 372         unsigned int port_number;
 373         unsigned char path_id;
 374         unsigned char target_id;
 375
 376         /* Used for vsc/vsp channel reset process */
 377         struct storvsc_cmd_request init_request;
 378         struct storvsc_cmd_request reset_request;
 379 };
 380
 381 struct hv_host_device {
 382         struct hv_device *dev;
 383         unsigned int port;
 384         unsigned char path;
 385         unsigned char target;
 386 };
 387
 388 struct storvsc_scan_work {
 389         struct work_struct work;
 390         struct Scsi_Host *host;
 391         uint lun;
 392 };
 393
 394 static void storvsc_device_scan(struct work_struct *work)
 395 {
 396         struct storvsc_scan_work *wrk;
 397         uint lun;
 398         struct scsi_device *sdev;
 399
 400         wrk = container_of(work, struct storvsc_scan_work, work);
 401         lun = wrk->lun;
 402
 403         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 404         if (!sdev)
 405                 goto done;
 406         scsi_rescan_device(&sdev->sdev_gendev);
 407         scsi_device_put(sdev);
 408
 409 done:
 410         kfree(wrk);
 411 }
 412
 413 static void storvsc_host_scan(struct work_struct *work)
 414 {
 415         struct storvsc_scan_work *wrk;
 416         struct Scsi_Host *host;
 417         struct scsi_device *sdev;
 418         unsigned long flags;
 419
 420         wrk = container_of(work, struct storvsc_scan_work, work);
 421         host = wrk->host;
 422
 423         /*
 424          * Before scanning the host, first check to see if any of the
 425          * currrently known devices have been hot removed. We issue a
 426          * "unit ready" command against all currently known devices.
 427          * This I/O will result in an error for devices that have been
 428          * removed. As part of handling the I/O error, we remove the device.
 429          *
 430          * When a LUN is added or removed, the host sends us a signal to
 431          * scan the host. Thus we are forced to discover the LUNs that
 432          * may have been removed this way.
 433          */
 434         mutex_lock(&host->scan_mutex);
 435         spin_lock_irqsave(host->host_lock, flags);
 436         list_for_each_entry(sdev, &host->__devices, siblings) {
 437                 spin_unlock_irqrestore(host->host_lock, flags);
 438                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 439                 spin_lock_irqsave(host->host_lock, flags);
 440                 continue;
 441         }
 442         spin_unlock_irqrestore(host->host_lock, flags);
 443         mutex_unlock(&host->scan_mutex);
 444         /*
 445          * Now scan the host to discover LUNs that may have been added.
 446          */
 447         scsi_scan_host(host);
 448
 449         kfree(wrk);
 450 }
 451
 452 static void storvsc_remove_lun(struct work_struct *work)
 453 {
 454         struct storvsc_scan_work *wrk;
 455         struct scsi_device *sdev;
 456
 457         wrk = container_of(work, struct storvsc_scan_work, work);
 458         if (!scsi_host_get(wrk->host))
 459                 goto done;
 460
 461         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 462
 463         if (sdev) {
 464                 scsi_remove_device(sdev);
 465                 scsi_device_put(sdev);
 466         }
 467         scsi_host_put(wrk->host);
 468
 469 done:
 470         kfree(wrk);
 471 }
 472
 473 /*
 474  * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 475  * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 476  */
 477
 478 static inline u16 storvsc_get_version(u8 major, u8 minor)
 479 {
 480         u16 version;
 481
 482         version = ((major << 8) | minor);
 483         return version;
 484 }
 485
 486 /*
 487  * We can get incoming messages from the host that are not in response to
 488  * messages that we have sent out. An example of this would be messages
 489  * received by the guest to notify dynamic addition/removal of LUNs. To
 490  * deal with potential race conditions where the driver may be in the
 491  * midst of being unloaded when we might receive an unsolicited message
 492  * from the host, we have implemented a mechanism to gurantee sequential
 493  * consistency:
 494  *
 495  * 1) Once the device is marked as being destroyed, we will fail all
 496  *    outgoing messages.
 497  * 2) We permit incoming messages when the device is being destroyed,
 498  *    only to properly account for messages already sent out.
 499  */
 500
 501 static inline struct storvsc_device *get_out_stor_device(
 502                                         struct hv_device *device)
 503 {
 504         struct storvsc_device *stor_device;
 505
 506         stor_device = hv_get_drvdata(device);
 507
 508         if (stor_device && stor_device->destroy)
 509                 stor_device = NULL;
 510
 511         return stor_device;
 512 }
 513
 514
 515 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 516 {
 517         dev->drain_notify = true;
 518         wait_event(dev->waiting_to_drain,
 519                    atomic_read(&dev->num_outstanding_req) == 0);
 520         dev->drain_notify = false;
 521 }
 522
 523 static inline struct storvsc_device *get_in_stor_device(
 524                                         struct hv_device *device)
 525 {
 526         struct storvsc_device *stor_device;
 527
 528         stor_device = hv_get_drvdata(device);
 529
 530         if (!stor_device)
 531                 goto get_in_err;
 532
 533         /*
 534          * If the device is being destroyed; allow incoming
 535          * traffic only to cleanup outstanding requests.
 536          */
 537
 538         if (stor_device->destroy  &&
 539                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 540                 stor_device = NULL;
 541
 542 get_in_err:
 543         return stor_device;
 544
 545 }
 546
 547 static void destroy_bounce_buffer(struct scatterlist *sgl,
 548                                   unsigned int sg_count)
 549 {
 550         int i;
 551         struct page *page_buf;
 552
 553         for (i = 0; i < sg_count; i++) {
 554                 page_buf = sg_page((&sgl[i]));
 555                 if (page_buf != NULL)
 556                         __free_page(page_buf);
 557         }
 558
 559         kfree(sgl);
 560 }
 561
 562 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 563 {
 564         int i;
 565
 566         /* No need to check */
 567         if (sg_count < 2)
 568                 return -1;
 569
 570         /* We have at least 2 sg entries */
 571         for (i = 0; i < sg_count; i++) {
 572                 if (i == 0) {
 573                         /* make sure 1st one does not have hole */
 574                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 575                                 return i;
 576                 } else if (i == sg_count - 1) {
 577                         /* make sure last one does not have hole */
 578                         if (sgl[i].offset != 0)
 579                                 return i;
 580                 } else {
 581                         /* make sure no hole in the middle */
 582                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 583                                 return i;
 584                 }
 585         }
 586         return -1;
 587 }
 588
 589 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 590                                                 unsigned int sg_count,
 591                                                 unsigned int len,
 592                                                 int write)
 593 {
 594         int i;
 595         int num_pages;
 596         struct scatterlist *bounce_sgl;
 597         struct page *page_buf;
 598         unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 599
 600         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 601
 602         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 603         if (!bounce_sgl)
 604                 return NULL;
 605
 606         sg_init_table(bounce_sgl, num_pages);
 607         for (i = 0; i < num_pages; i++) {
 608                 page_buf = alloc_page(GFP_ATOMIC);
 609                 if (!page_buf)
 610                         goto cleanup;
 611                 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 612         }
 613
 614         return bounce_sgl;
 615
 616 cleanup:
 617         destroy_bounce_buffer(bounce_sgl, num_pages);
 618         return NULL;
 619 }
 620
 621 /* Disgusting wrapper functions */
 622 static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
 623 {
 624         void *addr = kmap_atomic(sg_page(sgl + idx));
 625         return (unsigned long)addr;
 626 }
 627
 628 static inline void sg_kunmap_atomic(unsigned long addr)
 629 {
 630         kunmap_atomic((void *)addr);
 631 }
 632
 633
 634 /* Assume the original sgl has enough room */
 635 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 636                                             struct scatterlist *bounce_sgl,
 637                                             unsigned int orig_sgl_count,
 638                                             unsigned int bounce_sgl_count)
 639 {
 640         int i;
 641         int j = 0;
 642         unsigned long src, dest;
 643         unsigned int srclen, destlen, copylen;
 644         unsigned int total_copied = 0;
 645         unsigned long bounce_addr = 0;
 646         unsigned long dest_addr = 0;
 647         unsigned long flags;
 648
 649         local_irq_save(flags);
 650
 651         for (i = 0; i < orig_sgl_count; i++) {
 652                 dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 653                 dest = dest_addr;
 654                 destlen = orig_sgl[i].length;
 655
 656                 if (bounce_addr == 0)
 657                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 658
 659                 while (destlen) {
 660                         src = bounce_addr + bounce_sgl[j].offset;
 661                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 662
 663                         copylen = min(srclen, destlen);
 664                         memcpy((void *)dest, (void *)src, copylen);
 665
 666                         total_copied += copylen;
 667                         bounce_sgl[j].offset += copylen;
 668                         destlen -= copylen;
 669                         dest += copylen;
 670
 671                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 672                                 /* full */
 673                                 sg_kunmap_atomic(bounce_addr);
 674                                 j++;
 675
 676                                 /*
 677                                  * It is possible that the number of elements
 678                                  * in the bounce buffer may not be equal to
 679                                  * the number of elements in the original
 680                                  * scatter list. Handle this correctly.
 681                                  */
 682
 683                                 if (j == bounce_sgl_count) {
 684                                         /*
 685                                          * We are done; cleanup and return.
 686                                          */
 687                                         sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 688                                         local_irq_restore(flags);
 689                                         return total_copied;
 690                                 }
 691
 692                                 /* if we need to use another bounce buffer */
 693                                 if (destlen || i != orig_sgl_count - 1)
 694                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 695                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 696                                 /* unmap the last bounce that is < PAGE_SIZE */
 697                                 sg_kunmap_atomic(bounce_addr);
 698                         }
 699                 }
 700
 701                 sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 702         }
 703
 704         local_irq_restore(flags);
 705
 706         return total_copied;
 707 }
 708
 709 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 710 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 711                                           struct scatterlist *bounce_sgl,
 712                                           unsigned int orig_sgl_count)
 713 {
 714         int i;
 715         int j = 0;
 716         unsigned long src, dest;
 717         unsigned int srclen, destlen, copylen;
 718         unsigned int total_copied = 0;
 719         unsigned long bounce_addr = 0;
 720         unsigned long src_addr = 0;
 721         unsigned long flags;
 722
 723         local_irq_save(flags);
 724
 725         for (i = 0; i < orig_sgl_count; i++) {
 726                 src_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 727                 src = src_addr;
 728                 srclen = orig_sgl[i].length;
 729
 730                 if (bounce_addr == 0)
 731                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 732
 733                 while (srclen) {
 734                         /* assume bounce offset always == 0 */
 735                         dest = bounce_addr + bounce_sgl[j].length;
 736                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 737
 738                         copylen = min(srclen, destlen);
 739                         memcpy((void *)dest, (void *)src, copylen);
 740
 741                         total_copied += copylen;
 742                         bounce_sgl[j].length += copylen;
 743                         srclen -= copylen;
 744                         src += copylen;
 745
 746                         if (bounce_sgl[j].length == PAGE_SIZE) {
 747                                 /* full..move to next entry */
 748                                 sg_kunmap_atomic(bounce_addr);
 749                                 j++;
 750
 751                                 /* if we need to use another bounce buffer */
 752                                 if (srclen || i != orig_sgl_count - 1)
 753                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 754
 755                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 756                                 /* unmap the last bounce that is < PAGE_SIZE */
 757                                 sg_kunmap_atomic(bounce_addr);
 758                         }
 759                 }
 760
 761                 sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
 762         }
 763
 764         local_irq_restore(flags);
 765
 766         return total_copied;
 767 }
 768
 769 static void handle_sc_creation(struct vmbus_channel *new_sc)
 770 {
 771         struct hv_device *device = new_sc->primary_channel->device_obj;
 772         struct storvsc_device *stor_device;
 773         struct vmstorage_channel_properties props;
 774
 775         stor_device = get_out_stor_device(device);
 776         if (!stor_device)
 777                 return;
 778
 779         if (stor_device->open_sub_channel == false)
 780                 return;
 781
 782         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 783
 784         vmbus_open(new_sc,
 785                    storvsc_ringbuffer_size,
 786                    storvsc_ringbuffer_size,
 787                    (void *)&props,
 788                    sizeof(struct vmstorage_channel_properties),
 789                    storvsc_on_channel_callback, new_sc);
 790 }
 791
 792 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 793 {
 794         struct storvsc_device *stor_device;
 795         int num_cpus = num_online_cpus();
 796         int num_sc;
 797         struct storvsc_cmd_request *request;
 798         struct vstor_packet *vstor_packet;
 799         int ret, t;
 800
 801         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 802         stor_device = get_out_stor_device(device);
 803         if (!stor_device)
 804                 return;
 805
 806         request = &stor_device->init_request;
 807         vstor_packet = &request->vstor_packet;
 808
 809         stor_device->open_sub_channel = true;
 810         /*
 811          * Establish a handler for dealing with subchannels.
 812          */
 813         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 814
 815         /*
 816          * Check to see if sub-channels have already been created. This
 817          * can happen when this driver is re-loaded after unloading.
 818          */
 819
 820         if (vmbus_are_subchannels_present(device->channel))
 821                 return;
 822
 823         stor_device->open_sub_channel = false;
 824         /*
 825          * Request the host to create sub-channels.
 826          */
 827         memset(request, 0, sizeof(struct storvsc_cmd_request));
 828         init_completion(&request->wait_event);
 829         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 830         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 831         vstor_packet->sub_channel_count = num_sc;
 832
 833         ret = vmbus_sendpacket(device->channel, vstor_packet,
 834                                (sizeof(struct vstor_packet) -
 835                                vmscsi_size_delta),
 836                                (unsigned long)request,
 837                                VM_PKT_DATA_INBAND,
 838                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 839
 840         if (ret != 0)
 841                 return;
 842
 843         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 844         if (t == 0)
 845                 return;
 846
 847         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 848             vstor_packet->status != 0)
 849                 return;
 850
 851         /*
 852          * Now that we created the sub-channels, invoke the check; this
 853          * may trigger the callback.
 854          */
 855         stor_device->open_sub_channel = true;
 856         vmbus_are_subchannels_present(device->channel);
 857 }
 858
 859 static int storvsc_channel_init(struct hv_device *device)
 860 {
 861         struct storvsc_device *stor_device;
 862         struct storvsc_cmd_request *request;
 863         struct vstor_packet *vstor_packet;
 864         int ret, t;
 865         int max_chns;
 866         bool process_sub_channels = false;
 867
 868         stor_device = get_out_stor_device(device);
 869         if (!stor_device)
 870                 return -ENODEV;
 871
 872         request = &stor_device->init_request;
 873         vstor_packet = &request->vstor_packet;
 874
 875         /*
 876          * Now, initiate the vsc/vsp initialization protocol on the open
 877          * channel
 878          */
 879         memset(request, 0, sizeof(struct storvsc_cmd_request));
 880         init_completion(&request->wait_event);
 881         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 882         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 883
 884         ret = vmbus_sendpacket(device->channel, vstor_packet,
 885                                (sizeof(struct vstor_packet) -
 886                                vmscsi_size_delta),
 887                                (unsigned long)request,
 888                                VM_PKT_DATA_INBAND,
 889                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 890         if (ret != 0)
 891                 goto cleanup;
 892
 893         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 894         if (t == 0) {
 895                 ret = -ETIMEDOUT;
 896                 goto cleanup;
 897         }
 898
 899         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 900             vstor_packet->status != 0)
 901                 goto cleanup;
 902
 903
 904         /* reuse the packet for version range supported */
 905         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 906         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 907         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 908
 909         vstor_packet->version.major_minor =
 910                 storvsc_get_version(vmstor_current_major, vmstor_current_minor);
 911
 912         /*
 913          * The revision number is only used in Windows; set it to 0.
 914          */
 915         vstor_packet->version.revision = 0;
 916
 917         ret = vmbus_sendpacket(device->channel, vstor_packet,
 918                                (sizeof(struct vstor_packet) -
 919                                 vmscsi_size_delta),
 920                                (unsigned long)request,
 921                                VM_PKT_DATA_INBAND,
 922                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 923         if (ret != 0)
 924                 goto cleanup;
 925
 926         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 927         if (t == 0) {
 928                 ret = -ETIMEDOUT;
 929                 goto cleanup;
 930         }
 931
 932         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 933             vstor_packet->status != 0)
 934                 goto cleanup;
 935
 936
 937         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 938         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 939         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 940
 941         ret = vmbus_sendpacket(device->channel, vstor_packet,
 942                                (sizeof(struct vstor_packet) -
 943                                 vmscsi_size_delta),
 944                                (unsigned long)request,
 945                                VM_PKT_DATA_INBAND,
 946                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 947
 948         if (ret != 0)
 949                 goto cleanup;
 950
 951         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 952         if (t == 0) {
 953                 ret = -ETIMEDOUT;
 954                 goto cleanup;
 955         }
 956
 957         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 958             vstor_packet->status != 0)
 959                 goto cleanup;
 960
 961         /*
 962          * Check to see if multi-channel support is there.
 963          * Hosts that implement protocol version of 5.1 and above
 964          * support multi-channel.
 965          */
 966         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 967         if ((vmbus_proto_version != VERSION_WIN7) &&
 968            (vmbus_proto_version != VERSION_WS2008))  {
 969                 if (vstor_packet->storage_channel_properties.flags &
 970                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 971                         process_sub_channels = true;
 972         }
 973
 974         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 975         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 976         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 977
 978         ret = vmbus_sendpacket(device->channel, vstor_packet,
 979                                (sizeof(struct vstor_packet) -
 980                                 vmscsi_size_delta),
 981                                (unsigned long)request,
 982                                VM_PKT_DATA_INBAND,
 983                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 984
 985         if (ret != 0)
 986                 goto cleanup;
 987
 988         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 989         if (t == 0) {
 990                 ret = -ETIMEDOUT;
 991                 goto cleanup;
 992         }
 993
 994         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 995             vstor_packet->status != 0)
 996                 goto cleanup;
 997
 998         if (process_sub_channels)
 999                 handle_multichannel_storage(device, max_chns);
1000
1001
1002 cleanup:
1003         return ret;
1004 }
1005
1006 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1007                                 struct scsi_cmnd *scmnd,
1008                                 struct Scsi_Host *host,
1009                                 u8 asc, u8 ascq)
1010 {
1011         struct storvsc_scan_work *wrk;
1012         void (*process_err_fn)(struct work_struct *work);
1013         bool do_work = false;
1014
1015         switch (vm_srb->srb_status) {
1016         case SRB_STATUS_ERROR:
1017                 /*
1018                  * If there is an error; offline the device since all
1019                  * error recovery strategies would have already been
1020                  * deployed on the host side. However, if the command
1021                  * were a pass-through command deal with it appropriately.
1022                  */
1023                 switch (scmnd->cmnd[0]) {
1024                 case ATA_16:
1025                 case ATA_12:
1026                         set_host_byte(scmnd, DID_PASSTHROUGH);
1027                         break;
1028                 /*
1029                  * On Some Windows hosts TEST_UNIT_READY command can return
1030                  * SRB_STATUS_ERROR, let the upper level code deal with it
1031                  * based on the sense information.
1032                  */
1033                 case TEST_UNIT_READY:
1034                         break;
1035                 default:
1036                         set_host_byte(scmnd, DID_TARGET_FAILURE);
1037                 }
1038                 break;
1039         case SRB_STATUS_INVALID_LUN:
1040                 do_work = true;
1041                 process_err_fn = storvsc_remove_lun;
1042                 break;
1043         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
1044                 if ((asc == 0x2a) && (ascq == 0x9)) {
1045                         do_work = true;
1046                         process_err_fn = storvsc_device_scan;
1047                         /*
1048                          * Retry the I/O that trigerred this.
1049                          */
1050                         set_host_byte(scmnd, DID_REQUEUE);
1051                 }
1052                 break;
1053         }
1054
1055         if (!do_work)
1056                 return;
1057
1058         /*
1059          * We need to schedule work to process this error; schedule it.
1060          */
1061         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1062         if (!wrk) {
1063                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1064                 return;
1065         }
1066
1067         wrk->host = host;
1068         wrk->lun = vm_srb->lun;
1069         INIT_WORK(&wrk->work, process_err_fn);
1070         schedule_work(&wrk->work);
1071 }
1072
1073
1074 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
1075 {
1076         struct scsi_cmnd *scmnd = cmd_request->cmd;
1077         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1078         struct scsi_sense_hdr sense_hdr;
1079         struct vmscsi_request *vm_srb;
1080         struct Scsi_Host *host;
1081         struct storvsc_device *stor_dev;
1082         struct hv_device *dev = host_dev->dev;
1083
1084         stor_dev = get_in_stor_device(dev);
1085         host = stor_dev->host;
1086
1087         vm_srb = &cmd_request->vstor_packet.vm_srb;
1088         if (cmd_request->bounce_sgl_count) {
1089                 if (vm_srb->data_in == READ_TYPE)
1090                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1091                                         cmd_request->bounce_sgl,
1092                                         scsi_sg_count(scmnd),
1093                                         cmd_request->bounce_sgl_count);
1094                 destroy_bounce_buffer(cmd_request->bounce_sgl,
1095                                         cmd_request->bounce_sgl_count);
1096         }
1097
1098         scmnd->result = vm_srb->scsi_status;
1099
1100         if (scmnd->result) {
1101                 if (scsi_normalize_sense(scmnd->sense_buffer,
1102                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1103                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1104                                              &sense_hdr);
1105         }
1106
1107         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
1108                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1109                                          sense_hdr.ascq);
1110
1111         scsi_set_resid(scmnd,
1112                 cmd_request->data_buffer.len -
1113                 vm_srb->data_transfer_length);
1114
1115         scmnd->scsi_done(scmnd);
1116 }
1117
1118 static void storvsc_on_io_completion(struct hv_device *device,
1119                                   struct vstor_packet *vstor_packet,
1120                                   struct storvsc_cmd_request *request)
1121 {
1122         struct storvsc_device *stor_device;
1123         struct vstor_packet *stor_pkt;
1124
1125         stor_device = hv_get_drvdata(device);
1126         stor_pkt = &request->vstor_packet;
1127
1128         /*
1129          * The current SCSI handling on the host side does
1130          * not correctly handle:
1131          * INQUIRY command with page code parameter set to 0x80
1132          * MODE_SENSE command with cmd[2] == 0x1c
1133          *
1134          * Setup srb and scsi status so this won't be fatal.
1135          * We do this so we can distinguish truly fatal failues
1136          * (srb status == 0x4) and off-line the device in that case.
1137          */
1138
1139         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1140            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1141                 vstor_packet->vm_srb.scsi_status = 0;
1142                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1143         }
1144
1145
1146         /* Copy over the status...etc */
1147         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1148         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1149         stor_pkt->vm_srb.sense_info_length =
1150         vstor_packet->vm_srb.sense_info_length;
1151
1152
1153         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1154                 /* CHECK_CONDITION */
1155                 if (vstor_packet->vm_srb.srb_status &
1156                         SRB_STATUS_AUTOSENSE_VALID) {
1157                         /* autosense data available */
1158
1159                         memcpy(request->cmd->sense_buffer,
1160                                vstor_packet->vm_srb.sense_data,
1161                                vstor_packet->vm_srb.sense_info_length);
1162
1163                 }
1164         }
1165
1166         stor_pkt->vm_srb.data_transfer_length =
1167         vstor_packet->vm_srb.data_transfer_length;
1168
1169         storvsc_command_completion(request);
1170
1171         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1172                 stor_device->drain_notify)
1173                 wake_up(&stor_device->waiting_to_drain);
1174
1175
1176 }
1177
1178 static void storvsc_on_receive(struct hv_device *device,
1179                              struct vstor_packet *vstor_packet,
1180                              struct storvsc_cmd_request *request)
1181 {
1182         struct storvsc_scan_work *work;
1183         struct storvsc_device *stor_device;
1184
1185         switch (vstor_packet->operation) {
1186         case VSTOR_OPERATION_COMPLETE_IO:
1187                 storvsc_on_io_completion(device, vstor_packet, request);
1188                 break;
1189
1190         case VSTOR_OPERATION_REMOVE_DEVICE:
1191         case VSTOR_OPERATION_ENUMERATE_BUS:
1192                 stor_device = get_in_stor_device(device);
1193                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1194                 if (!work)
1195                         return;
1196
1197                 INIT_WORK(&work->work, storvsc_host_scan);
1198                 work->host = stor_device->host;
1199                 schedule_work(&work->work);
1200                 break;
1201
1202         default:
1203                 break;
1204         }
1205 }
1206
1207 static void storvsc_on_channel_callback(void *context)
1208 {
1209         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1210         struct hv_device *device;
1211         struct storvsc_device *stor_device;
1212         u32 bytes_recvd;
1213         u64 request_id;
1214         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1215         struct storvsc_cmd_request *request;
1216         int ret;
1217
1218         if (channel->primary_channel != NULL)
1219                 device = channel->primary_channel->device_obj;
1220         else
1221                 device = channel->device_obj;
1222
1223         stor_device = get_in_stor_device(device);
1224         if (!stor_device)
1225                 return;
1226
1227         do {
1228                 ret = vmbus_recvpacket(channel, packet,
1229                                        ALIGN((sizeof(struct vstor_packet) -
1230                                              vmscsi_size_delta), 8),
1231                                        &bytes_recvd, &request_id);
1232                 if (ret == 0 && bytes_recvd > 0) {
1233
1234                         request = (struct storvsc_cmd_request *)
1235                                         (unsigned long)request_id;
1236
1237                         if ((request == &stor_device->init_request) ||
1238                             (request == &stor_device->reset_request)) {
1239
1240                                 memcpy(&request->vstor_packet, packet,
1241                                        (sizeof(struct vstor_packet) -
1242                                         vmscsi_size_delta));
1243                                 complete(&request->wait_event);
1244                         } else {
1245                                 storvsc_on_receive(device,
1246                                                 (struct vstor_packet *)packet,
1247                                                 request);
1248                         }
1249                 } else {
1250                         break;
1251                 }
1252         } while (1);
1253
1254         return;
1255 }
1256
1257 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1258 {
1259         struct vmstorage_channel_properties props;
1260         int ret;
1261
1262         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1263
1264         ret = vmbus_open(device->channel,
1265                          ring_size,
1266                          ring_size,
1267                          (void *)&props,
1268                          sizeof(struct vmstorage_channel_properties),
1269                          storvsc_on_channel_callback, device->channel);
1270
1271         if (ret != 0)
1272                 return ret;
1273
1274         ret = storvsc_channel_init(device);
1275
1276         return ret;
1277 }
1278
1279 static int storvsc_dev_remove(struct hv_device *device)
1280 {
1281         struct storvsc_device *stor_device;
1282         unsigned long flags;
1283
1284         stor_device = hv_get_drvdata(device);
1285
1286         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1287         stor_device->destroy = true;
1288         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1289
1290         /*
1291          * At this point, all outbound traffic should be disable. We
1292          * only allow inbound traffic (responses) to proceed so that
1293          * outstanding requests can be completed.
1294          */
1295
1296         storvsc_wait_to_drain(stor_device);
1297
1298         /*
1299          * Since we have already drained, we don't need to busy wait
1300          * as was done in final_release_stor_device()
1301          * Note that we cannot set the ext pointer to NULL until
1302          * we have drained - to drain the outgoing packets, we need to
1303          * allow incoming packets.
1304          */
1305         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1306         hv_set_drvdata(device, NULL);
1307         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1308
1309         /* Close the channel */
1310         vmbus_close(device->channel);
1311
1312         kfree(stor_device);
1313         return 0;
1314 }
1315
1316 static int storvsc_do_io(struct hv_device *device,
1317                               struct storvsc_cmd_request *request)
1318 {
1319         struct storvsc_device *stor_device;
1320         struct vstor_packet *vstor_packet;
1321         struct vmbus_channel *outgoing_channel;
1322         int ret = 0;
1323
1324         vstor_packet = &request->vstor_packet;
1325         stor_device = get_out_stor_device(device);
1326
1327         if (!stor_device)
1328                 return -ENODEV;
1329
1330
1331         request->device  = device;
1332         /*
1333          * Select an an appropriate channel to send the request out.
1334          */
1335
1336         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1337
1338
1339         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1340
1341         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1342                                         vmscsi_size_delta);
1343
1344
1345         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1346
1347
1348         vstor_packet->vm_srb.data_transfer_length =
1349         request->data_buffer.len;
1350
1351         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1352
1353         if (request->data_buffer.len) {
1354                 ret = vmbus_sendpacket_multipagebuffer(outgoing_channel,
1355                                 &request->data_buffer,
1356                                 vstor_packet,
1357                                 (sizeof(struct vstor_packet) -
1358                                 vmscsi_size_delta),
1359                                 (unsigned long)request);
1360         } else {
1361                 ret = vmbus_sendpacket(device->channel, vstor_packet,
1362                                (sizeof(struct vstor_packet) -
1363                                 vmscsi_size_delta),
1364                                (unsigned long)request,
1365                                VM_PKT_DATA_INBAND,
1366                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1367         }
1368
1369         if (ret != 0)
1370                 return ret;
1371
1372         atomic_inc(&stor_device->num_outstanding_req);
1373
1374         return ret;
1375 }
1376
1377 static int storvsc_device_configure(struct scsi_device *sdevice)
1378 {
1379         scsi_change_queue_depth(sdevice, STORVSC_MAX_IO_REQUESTS);
1380
1381         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1382
1383         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1384
1385         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1386
1387         sdevice->no_write_same = 1;
1388
1389         /*
1390          * Add blist flags to permit the reading of the VPD pages even when
1391          * the target may claim SPC-2 compliance. MSFT targets currently
1392          * claim SPC-2 compliance while they implement post SPC-2 features.
1393          * With this patch we can correctly handle WRITE_SAME_16 issues.
1394          */
1395         sdevice->sdev_bflags |= msft_blist_flags;
1396
1397         /*
1398          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1399          * if the device is a MSFT virtual device.
1400          */
1401         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1402                 switch (vmbus_proto_version) {
1403                 case VERSION_WIN8:
1404                 case VERSION_WIN8_1:
1405                         sdevice->scsi_level = SCSI_SPC_3;
1406                         break;
1407                 }
1408         }
1409
1410         return 0;
1411 }
1412
1413 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1414                            sector_t capacity, int *info)
1415 {
1416         sector_t nsect = capacity;
1417         sector_t cylinders = nsect;
1418         int heads, sectors_pt;
1419
1420         /*
1421          * We are making up these values; let us keep it simple.
1422          */
1423         heads = 0xff;
1424         sectors_pt = 0x3f;      /* Sectors per track */
1425         sector_div(cylinders, heads * sectors_pt);
1426         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1427                 cylinders = 0xffff;
1428
1429         info[0] = heads;
1430         info[1] = sectors_pt;
1431         info[2] = (int)cylinders;
1432
1433         return 0;
1434 }
1435
1436 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1437 {
1438         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1439         struct hv_device *device = host_dev->dev;
1440
1441         struct storvsc_device *stor_device;
1442         struct storvsc_cmd_request *request;
1443         struct vstor_packet *vstor_packet;
1444         int ret, t;
1445
1446
1447         stor_device = get_out_stor_device(device);
1448         if (!stor_device)
1449                 return FAILED;
1450
1451         request = &stor_device->reset_request;
1452         vstor_packet = &request->vstor_packet;
1453
1454         init_completion(&request->wait_event);
1455
1456         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1457         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1458         vstor_packet->vm_srb.path_id = stor_device->path_id;
1459
1460         ret = vmbus_sendpacket(device->channel, vstor_packet,
1461                                (sizeof(struct vstor_packet) -
1462                                 vmscsi_size_delta),
1463                                (unsigned long)&stor_device->reset_request,
1464                                VM_PKT_DATA_INBAND,
1465                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1466         if (ret != 0)
1467                 return FAILED;
1468
1469         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1470         if (t == 0)
1471                 return TIMEOUT_ERROR;
1472
1473
1474         /*
1475          * At this point, all outstanding requests in the adapter
1476          * should have been flushed out and return to us
1477          * There is a potential race here where the host may be in
1478          * the process of responding when we return from here.
1479          * Just wait for all in-transit packets to be accounted for
1480          * before we return from here.
1481          */
1482         storvsc_wait_to_drain(stor_device);
1483
1484         return SUCCESS;
1485 }
1486
1487 /*
1488  * The host guarantees to respond to each command, although I/O latencies might
1489  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1490  * chance to perform EH.
1491  */
1492 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1493 {
1494         return BLK_EH_RESET_TIMER;
1495 }
1496
1497 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1498 {
1499         bool allowed = true;
1500         u8 scsi_op = scmnd->cmnd[0];
1501
1502         switch (scsi_op) {
1503         /* the host does not handle WRITE_SAME, log accident usage */
1504         case WRITE_SAME:
1505         /*
1506          * smartd sends this command and the host does not handle
1507          * this. So, don't send it.
1508          */
1509         case SET_WINDOW:
1510                 scmnd->result = ILLEGAL_REQUEST << 16;
1511                 allowed = false;
1512                 break;
1513         default:
1514                 break;
1515         }
1516         return allowed;
1517 }
1518
1519 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1520 {
1521         int ret;
1522         struct hv_host_device *host_dev = shost_priv(host);
1523         struct hv_device *dev = host_dev->dev;
1524         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1525         int i;
1526         struct scatterlist *sgl;
1527         unsigned int sg_count = 0;
1528         struct vmscsi_request *vm_srb;
1529
1530         if (vmstor_current_major <= VMSTOR_WIN8_MAJOR) {
1531                 /*
1532                  * On legacy hosts filter unimplemented commands.
1533                  * Future hosts are expected to correctly handle
1534                  * unsupported commands. Furthermore, it is
1535                  * possible that some of the currently
1536                  * unsupported commands maybe supported in
1537                  * future versions of the host.
1538                  */
1539                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1540                         scmnd->scsi_done(scmnd);
1541                         return 0;
1542                 }
1543         }
1544
1545         /* Setup the cmd request */
1546         cmd_request->cmd = scmnd;
1547
1548         vm_srb = &cmd_request->vstor_packet.vm_srb;
1549         vm_srb->win8_extension.time_out_value = 60;
1550
1551         vm_srb->win8_extension.srb_flags |=
1552                 (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1553                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1554
1555         /* Build the SRB */
1556         switch (scmnd->sc_data_direction) {
1557         case DMA_TO_DEVICE:
1558                 vm_srb->data_in = WRITE_TYPE;
1559                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1560                 break;
1561         case DMA_FROM_DEVICE:
1562                 vm_srb->data_in = READ_TYPE;
1563                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1564                 break;
1565         default:
1566                 vm_srb->data_in = UNKNOWN_TYPE;
1567                 vm_srb->win8_extension.srb_flags |= (SRB_FLAGS_DATA_IN |
1568                                                      SRB_FLAGS_DATA_OUT);
1569                 break;
1570         }
1571
1572
1573         vm_srb->port_number = host_dev->port;
1574         vm_srb->path_id = scmnd->device->channel;
1575         vm_srb->target_id = scmnd->device->id;
1576         vm_srb->lun = scmnd->device->lun;
1577
1578         vm_srb->cdb_length = scmnd->cmd_len;
1579
1580         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1581
1582         cmd_request->data_buffer.len = scsi_bufflen(scmnd);
1583         if (scsi_sg_count(scmnd)) {
1584                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1585                 sg_count = scsi_sg_count(scmnd);
1586
1587                 /* check if we need to bounce the sgl */
1588                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1589                         cmd_request->bounce_sgl =
1590                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1591                                                      scsi_bufflen(scmnd),
1592                                                      vm_srb->data_in);
1593                         if (!cmd_request->bounce_sgl)
1594                                 return SCSI_MLQUEUE_HOST_BUSY;
1595
1596                         cmd_request->bounce_sgl_count =
1597                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1598                                         PAGE_SHIFT;
1599
1600                         if (vm_srb->data_in == WRITE_TYPE)
1601                                 copy_to_bounce_buffer(sgl,
1602                                         cmd_request->bounce_sgl,
1603                                         scsi_sg_count(scmnd));
1604
1605                         sgl = cmd_request->bounce_sgl;
1606                         sg_count = cmd_request->bounce_sgl_count;
1607                 }
1608
1609                 cmd_request->data_buffer.offset = sgl[0].offset;
1610
1611                 for (i = 0; i < sg_count; i++)
1612                         cmd_request->data_buffer.pfn_array[i] =
1613                                 page_to_pfn(sg_page((&sgl[i])));
1614
1615         } else if (scsi_sglist(scmnd)) {
1616                 cmd_request->data_buffer.offset =
1617                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1618                 cmd_request->data_buffer.pfn_array[0] =
1619                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1620         }
1621
1622         /* Invokes the vsc to start an IO */
1623         ret = storvsc_do_io(dev, cmd_request);
1624
1625         if (ret == -EAGAIN) {
1626                 /* no more space */
1627
1628                 if (cmd_request->bounce_sgl_count)
1629                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1630                                         cmd_request->bounce_sgl_count);
1631
1632                 return SCSI_MLQUEUE_DEVICE_BUSY;
1633         }
1634
1635         return 0;
1636 }
1637
1638 static struct scsi_host_template scsi_driver = {
1639         .module =               THIS_MODULE,
1640         .name =                 "storvsc_host_t",
1641         .cmd_size =             sizeof(struct storvsc_cmd_request),
1642         .bios_param =           storvsc_get_chs,
1643         .queuecommand =         storvsc_queuecommand,
1644         .eh_host_reset_handler =        storvsc_host_reset_handler,
1645         .proc_name =            "storvsc_host",
1646         .eh_timed_out =         storvsc_eh_timed_out,
1647         .slave_configure =      storvsc_device_configure,
1648         .cmd_per_lun =          255,
1649         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1650         .this_id =              -1,
1651         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1652         /* currently 32 */
1653         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1654         .use_clustering =       DISABLE_CLUSTERING,
1655         /* Make sure we dont get a sg segment crosses a page boundary */
1656         .dma_boundary =         PAGE_SIZE-1,
1657         .no_write_same =        1,
1658 };
1659
1660 enum {
1661         SCSI_GUID,
1662         IDE_GUID,
1663         SFC_GUID,
1664 };
1665
1666 static const struct hv_vmbus_device_id id_table[] = {
1667         /* SCSI guid */
1668         { HV_SCSI_GUID,
1669           .driver_data = SCSI_GUID
1670         },
1671         /* IDE guid */
1672         { HV_IDE_GUID,
1673           .driver_data = IDE_GUID
1674         },
1675         /* Fibre Channel GUID */
1676         {
1677           HV_SYNTHFC_GUID,
1678           .driver_data = SFC_GUID
1679         },
1680         { },
1681 };
1682
1683 MODULE_DEVICE_TABLE(vmbus, id_table);
1684
1685 static int storvsc_probe(struct hv_device *device,
1686                         const struct hv_vmbus_device_id *dev_id)
1687 {
1688         int ret;
1689         struct Scsi_Host *host;
1690         struct hv_host_device *host_dev;
1691         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1692         int target = 0;
1693         struct storvsc_device *stor_device;
1694         int max_luns_per_target;
1695         int max_targets;
1696         int max_channels;
1697
1698         /*
1699          * Based on the windows host we are running on,
1700          * set state to properly communicate with the host.
1701          */
1702
1703         switch (vmbus_proto_version) {
1704         case VERSION_WS2008:
1705         case VERSION_WIN7:
1706                 sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
1707                 vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1708                 vmstor_current_major = VMSTOR_WIN7_MAJOR;
1709                 vmstor_current_minor = VMSTOR_WIN7_MINOR;
1710                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1711                 max_targets = STORVSC_IDE_MAX_TARGETS;
1712                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1713                 break;
1714         default:
1715                 sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
1716                 vmscsi_size_delta = 0;
1717                 vmstor_current_major = VMSTOR_WIN8_MAJOR;
1718                 vmstor_current_minor = VMSTOR_WIN8_MINOR;
1719                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1720                 max_targets = STORVSC_MAX_TARGETS;
1721                 max_channels = STORVSC_MAX_CHANNELS;
1722                 break;
1723         }
1724
1725         if (dev_id->driver_data == SFC_GUID)
1726                 scsi_driver.can_queue = (STORVSC_MAX_IO_REQUESTS *
1727                                          STORVSC_FC_MAX_TARGETS);
1728         host = scsi_host_alloc(&scsi_driver,
1729                                sizeof(struct hv_host_device));
1730         if (!host)
1731                 return -ENOMEM;
1732
1733         host_dev = shost_priv(host);
1734         memset(host_dev, 0, sizeof(struct hv_host_device));
1735
1736         host_dev->port = host->host_no;
1737         host_dev->dev = device;
1738
1739
1740         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1741         if (!stor_device) {
1742                 ret = -ENOMEM;
1743                 goto err_out0;
1744         }
1745
1746         stor_device->destroy = false;
1747         stor_device->open_sub_channel = false;
1748         init_waitqueue_head(&stor_device->waiting_to_drain);
1749         stor_device->device = device;
1750         stor_device->host = host;
1751         hv_set_drvdata(device, stor_device);
1752
1753         stor_device->port_number = host->host_no;
1754         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1755         if (ret)
1756                 goto err_out1;
1757
1758         host_dev->path = stor_device->path_id;
1759         host_dev->target = stor_device->target_id;
1760
1761         switch (dev_id->driver_data) {
1762         case SFC_GUID:
1763                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1764                 host->max_id = STORVSC_FC_MAX_TARGETS;
1765                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1766                 break;
1767
1768         case SCSI_GUID:
1769                 host->max_lun = max_luns_per_target;
1770                 host->max_id = max_targets;
1771                 host->max_channel = max_channels - 1;
1772                 break;
1773
1774         default:
1775                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1776                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1777                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1778                 break;
1779         }
1780         /* max cmd length */
1781         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1782
1783         /* Register the HBA and start the scsi bus scan */
1784         ret = scsi_add_host(host, &device->device);
1785         if (ret != 0)
1786                 goto err_out2;
1787
1788         if (!dev_is_ide) {
1789                 scsi_scan_host(host);
1790         } else {
1791                 target = (device->dev_instance.b[5] << 8 |
1792                          device->dev_instance.b[4]);
1793                 ret = scsi_add_device(host, 0, target, 0);
1794                 if (ret) {
1795                         scsi_remove_host(host);
1796                         goto err_out2;
1797                 }
1798         }
1799         return 0;
1800
1801 err_out2:
1802         /*
1803          * Once we have connected with the host, we would need to
1804          * to invoke storvsc_dev_remove() to rollback this state and
1805          * this call also frees up the stor_device; hence the jump around
1806          * err_out1 label.
1807          */
1808         storvsc_dev_remove(device);
1809         goto err_out0;
1810
1811 err_out1:
1812         kfree(stor_device);
1813
1814 err_out0:
1815         scsi_host_put(host);
1816         return ret;
1817 }
1818
1819 static int storvsc_remove(struct hv_device *dev)
1820 {
1821         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1822         struct Scsi_Host *host = stor_device->host;
1823
1824         scsi_remove_host(host);
1825         storvsc_dev_remove(dev);
1826         scsi_host_put(host);
1827
1828         return 0;
1829 }
1830
1831 static struct hv_driver storvsc_drv = {
1832         .name = KBUILD_MODNAME,
1833         .id_table = id_table,
1834         .probe = storvsc_probe,
1835         .remove = storvsc_remove,
1836 };
1837
1838 static int __init storvsc_drv_init(void)
1839 {
1840         u32 max_outstanding_req_per_channel;
1841
1842         /*
1843          * Divide the ring buffer data size (which is 1 page less
1844          * than the ring buffer size since that page is reserved for
1845          * the ring buffer indices) by the max request size (which is
1846          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1847          */
1848         max_outstanding_req_per_channel =
1849                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1850                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1851                 sizeof(struct vstor_packet) + sizeof(u64) -
1852                 vmscsi_size_delta,
1853                 sizeof(u64)));
1854
1855         if (max_outstanding_req_per_channel <
1856             STORVSC_MAX_IO_REQUESTS)
1857                 return -EINVAL;
1858
1859         return vmbus_driver_register(&storvsc_drv);
1860 }
1861
1862 static void __exit storvsc_drv_exit(void)
1863 {
1864         vmbus_driver_unregister(&storvsc_drv);
1865 }
1866
1867 MODULE_LICENSE("GPL");
1868 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1869 module_init(storvsc_drv_init);
1870 module_exit(storvsc_drv_exit);