kernel/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         unsigned long flags;
 430
 431         wrk = container_of(work, struct storvsc_scan_work, work);
 432         host = wrk->host;
 433
 434         /*
 435          * Before scanning the host, first check to see if any of the
 436          * currrently known devices have been hot removed. We issue a
 437          * "unit ready" command against all currently known devices.
 438          * This I/O will result in an error for devices that have been
 439          * removed. As part of handling the I/O error, we remove the device.
 440          *
 441          * When a LUN is added or removed, the host sends us a signal to
 442          * scan the host. Thus we are forced to discover the LUNs that
 443          * may have been removed this way.
 444          */
 445         mutex_lock(&host->scan_mutex);
 446         spin_lock_irqsave(host->host_lock, flags);
 447         list_for_each_entry(sdev, &host->__devices, siblings) {
 448                 spin_unlock_irqrestore(host->host_lock, flags);
 449                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 450                 spin_lock_irqsave(host->host_lock, flags);
 451                 continue;
 452         }
 453         spin_unlock_irqrestore(host->host_lock, flags);
 454         mutex_unlock(&host->scan_mutex);
 455         /*
 456          * Now scan the host to discover LUNs that may have been added.
 457          */
 458         scsi_scan_host(host);
 459
 460         kfree(wrk);
 461 }
 462
 463 static void storvsc_remove_lun(struct work_struct *work)
 464 {
 465         struct storvsc_scan_work *wrk;
 466         struct scsi_device *sdev;
 467
 468         wrk = container_of(work, struct storvsc_scan_work, work);
 469         if (!scsi_host_get(wrk->host))
 470                 goto done;
 471
 472         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 473
 474         if (sdev) {
 475                 scsi_remove_device(sdev);
 476                 scsi_device_put(sdev);
 477         }
 478         scsi_host_put(wrk->host);
 479
 480 done:
 481         kfree(wrk);
 482 }
 483
 484 /*
 485  * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 486  * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 487  */
 488
 489 static inline u16 storvsc_get_version(u8 major, u8 minor)
 490 {
 491         u16 version;
 492
 493         version = ((major << 8) | minor);
 494         return version;
 495 }
 496
 497 /*
 498  * We can get incoming messages from the host that are not in response to
 499  * messages that we have sent out. An example of this would be messages
 500  * received by the guest to notify dynamic addition/removal of LUNs. To
 501  * deal with potential race conditions where the driver may be in the
 502  * midst of being unloaded when we might receive an unsolicited message
 503  * from the host, we have implemented a mechanism to gurantee sequential
 504  * consistency:
 505  *
 506  * 1) Once the device is marked as being destroyed, we will fail all
 507  *    outgoing messages.
 508  * 2) We permit incoming messages when the device is being destroyed,
 509  *    only to properly account for messages already sent out.
 510  */
 511
 512 static inline struct storvsc_device *get_out_stor_device(
 513                                         struct hv_device *device)
 514 {
 515         struct storvsc_device *stor_device;
 516
 517         stor_device = hv_get_drvdata(device);
 518
 519         if (stor_device && stor_device->destroy)
 520                 stor_device = NULL;
 521
 522         return stor_device;
 523 }
 524
 525
 526 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 527 {
 528         dev->drain_notify = true;
 529         wait_event(dev->waiting_to_drain,
 530                    atomic_read(&dev->num_outstanding_req) == 0);
 531         dev->drain_notify = false;
 532 }
 533
 534 static inline struct storvsc_device *get_in_stor_device(
 535                                         struct hv_device *device)
 536 {
 537         struct storvsc_device *stor_device;
 538
 539         stor_device = hv_get_drvdata(device);
 540
 541         if (!stor_device)
 542                 goto get_in_err;
 543
 544         /*
 545          * If the device is being destroyed; allow incoming
 546          * traffic only to cleanup outstanding requests.
 547          */
 548
 549         if (stor_device->destroy  &&
 550                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 551                 stor_device = NULL;
 552
 553 get_in_err:
 554         return stor_device;
 555
 556 }
 557
 558 static void destroy_bounce_buffer(struct scatterlist *sgl,
 559                                   unsigned int sg_count)
 560 {
 561         int i;
 562         struct page *page_buf;
 563
 564         for (i = 0; i < sg_count; i++) {
 565                 page_buf = sg_page((&sgl[i]));
 566                 if (page_buf != NULL)
 567                         __free_page(page_buf);
 568         }
 569
 570         kfree(sgl);
 571 }
 572
 573 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 574 {
 575         int i;
 576
 577         /* No need to check */
 578         if (sg_count < 2)
 579                 return -1;
 580
 581         /* We have at least 2 sg entries */
 582         for (i = 0; i < sg_count; i++) {
 583                 if (i == 0) {
 584                         /* make sure 1st one does not have hole */
 585                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 586                                 return i;
 587                 } else if (i == sg_count - 1) {
 588                         /* make sure last one does not have hole */
 589                         if (sgl[i].offset != 0)
 590                                 return i;
 591                 } else {
 592                         /* make sure no hole in the middle */
 593                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 594                                 return i;
 595                 }
 596         }
 597         return -1;
 598 }
 599
 600 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 601                                                 unsigned int sg_count,
 602                                                 unsigned int len,
 603                                                 int write)
 604 {
 605         int i;
 606         int num_pages;
 607         struct scatterlist *bounce_sgl;
 608         struct page *page_buf;
 609         unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 610
 611         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 612
 613         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 614         if (!bounce_sgl)
 615                 return NULL;
 616
 617         sg_init_table(bounce_sgl, num_pages);
 618         for (i = 0; i < num_pages; i++) {
 619                 page_buf = alloc_page(GFP_ATOMIC);
 620                 if (!page_buf)
 621                         goto cleanup;
 622                 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 623         }
 624
 625         return bounce_sgl;
 626
 627 cleanup:
 628         destroy_bounce_buffer(bounce_sgl, num_pages);
 629         return NULL;
 630 }
 631
 632 /* Assume the original sgl has enough room */
 633 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 634                                             struct scatterlist *bounce_sgl,
 635                                             unsigned int orig_sgl_count,
 636                                             unsigned int bounce_sgl_count)
 637 {
 638         int i;
 639         int j = 0;
 640         unsigned long src, dest;
 641         unsigned int srclen, destlen, copylen;
 642         unsigned int total_copied = 0;
 643         unsigned long bounce_addr = 0;
 644         unsigned long dest_addr = 0;
 645         unsigned long flags;
 646         struct scatterlist *cur_dest_sgl;
 647         struct scatterlist *cur_src_sgl;
 648
 649         local_irq_save(flags);
 650         cur_dest_sgl = orig_sgl;
 651         cur_src_sgl = bounce_sgl;
 652         for (i = 0; i < orig_sgl_count; i++) {
 653                 dest_addr = (unsigned long)
 654                                 kmap_atomic(sg_page(cur_dest_sgl)) +
 655                                 cur_dest_sgl->offset;
 656                 dest = dest_addr;
 657                 destlen = cur_dest_sgl->length;
 658
 659                 if (bounce_addr == 0)
 660                         bounce_addr = (unsigned long)kmap_atomic(
 661                                                         sg_page(cur_src_sgl));
 662
 663                 while (destlen) {
 664                         src = bounce_addr + cur_src_sgl->offset;
 665                         srclen = cur_src_sgl->length - cur_src_sgl->offset;
 666
 667                         copylen = min(srclen, destlen);
 668                         memcpy((void *)dest, (void *)src, copylen);
 669
 670                         total_copied += copylen;
 671                         cur_src_sgl->offset += copylen;
 672                         destlen -= copylen;
 673                         dest += copylen;
 674
 675                         if (cur_src_sgl->offset == cur_src_sgl->length) {
 676                                 /* full */
 677                                 kunmap_atomic((void *)bounce_addr);
 678                                 j++;
 679
 680                                 /*
 681                                  * It is possible that the number of elements
 682                                  * in the bounce buffer may not be equal to
 683                                  * the number of elements in the original
 684                                  * scatter list. Handle this correctly.
 685                                  */
 686
 687                                 if (j == bounce_sgl_count) {
 688                                         /*
 689                                          * We are done; cleanup and return.
 690                                          */
 691                                         kunmap_atomic((void *)(dest_addr -
 692                                                 cur_dest_sgl->offset));
 693                                         local_irq_restore(flags);
 694                                         return total_copied;
 695                                 }
 696
 697                                 /* if we need to use another bounce buffer */
 698                                 if (destlen || i != orig_sgl_count - 1) {
 699                                         cur_src_sgl = sg_next(cur_src_sgl);
 700                                         bounce_addr = (unsigned long)
 701                                                         kmap_atomic(
 702                                                         sg_page(cur_src_sgl));
 703                                 }
 704                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 705                                 /* unmap the last bounce that is < PAGE_SIZE */
 706                                 kunmap_atomic((void *)bounce_addr);
 707                         }
 708                 }
 709
 710                 kunmap_atomic((void *)(dest_addr - cur_dest_sgl->offset));
 711                 cur_dest_sgl = sg_next(cur_dest_sgl);
 712         }
 713
 714         local_irq_restore(flags);
 715
 716         return total_copied;
 717 }
 718
 719 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 720 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 721                                           struct scatterlist *bounce_sgl,
 722                                           unsigned int orig_sgl_count)
 723 {
 724         int i;
 725         int j = 0;
 726         unsigned long src, dest;
 727         unsigned int srclen, destlen, copylen;
 728         unsigned int total_copied = 0;
 729         unsigned long bounce_addr = 0;
 730         unsigned long src_addr = 0;
 731         unsigned long flags;
 732         struct scatterlist *cur_src_sgl;
 733         struct scatterlist *cur_dest_sgl;
 734
 735         local_irq_save(flags);
 736
 737         cur_src_sgl = orig_sgl;
 738         cur_dest_sgl = bounce_sgl;
 739
 740         for (i = 0; i < orig_sgl_count; i++) {
 741                 src_addr = (unsigned long)
 742                                 kmap_atomic(sg_page(cur_src_sgl)) +
 743                                 cur_src_sgl->offset;
 744                 src = src_addr;
 745                 srclen = cur_src_sgl->length;
 746
 747                 if (bounce_addr == 0)
 748                         bounce_addr = (unsigned long)
 749                                         kmap_atomic(sg_page(cur_dest_sgl));
 750
 751                 while (srclen) {
 752                         /* assume bounce offset always == 0 */
 753                         dest = bounce_addr + cur_dest_sgl->length;
 754                         destlen = PAGE_SIZE - cur_dest_sgl->length;
 755
 756                         copylen = min(srclen, destlen);
 757                         memcpy((void *)dest, (void *)src, copylen);
 758
 759                         total_copied += copylen;
 760                         cur_dest_sgl->length += copylen;
 761                         srclen -= copylen;
 762                         src += copylen;
 763
 764                         if (cur_dest_sgl->length == PAGE_SIZE) {
 765                                 /* full..move to next entry */
 766                                 kunmap_atomic((void *)bounce_addr);
 767                                 bounce_addr = 0;
 768                                 j++;
 769                         }
 770
 771                         /* if we need to use another bounce buffer */
 772                         if (srclen && bounce_addr == 0) {
 773                                 cur_dest_sgl = sg_next(cur_dest_sgl);
 774                                 bounce_addr = (unsigned long)
 775                                                 kmap_atomic(
 776                                                 sg_page(cur_dest_sgl));
 777                         }
 778
 779                 }
 780
 781                 kunmap_atomic((void *)(src_addr - cur_src_sgl->offset));
 782                 cur_src_sgl = sg_next(cur_src_sgl);
 783         }
 784
 785         if (bounce_addr)
 786                 kunmap_atomic((void *)bounce_addr);
 787
 788         local_irq_restore(flags);
 789
 790         return total_copied;
 791 }
 792
 793 static void handle_sc_creation(struct vmbus_channel *new_sc)
 794 {
 795         struct hv_device *device = new_sc->primary_channel->device_obj;
 796         struct storvsc_device *stor_device;
 797         struct vmstorage_channel_properties props;
 798
 799         stor_device = get_out_stor_device(device);
 800         if (!stor_device)
 801                 return;
 802
 803         if (stor_device->open_sub_channel == false)
 804                 return;
 805
 806         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 807
 808         vmbus_open(new_sc,
 809                    storvsc_ringbuffer_size,
 810                    storvsc_ringbuffer_size,
 811                    (void *)&props,
 812                    sizeof(struct vmstorage_channel_properties),
 813                    storvsc_on_channel_callback, new_sc);
 814 }
 815
 816 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 817 {
 818         struct storvsc_device *stor_device;
 819         int num_cpus = num_online_cpus();
 820         int num_sc;
 821         struct storvsc_cmd_request *request;
 822         struct vstor_packet *vstor_packet;
 823         int ret, t;
 824
 825         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 826         stor_device = get_out_stor_device(device);
 827         if (!stor_device)
 828                 return;
 829
 830         request = &stor_device->init_request;
 831         vstor_packet = &request->vstor_packet;
 832
 833         stor_device->open_sub_channel = true;
 834         /*
 835          * Establish a handler for dealing with subchannels.
 836          */
 837         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 838
 839         /*
 840          * Check to see if sub-channels have already been created. This
 841          * can happen when this driver is re-loaded after unloading.
 842          */
 843
 844         if (vmbus_are_subchannels_present(device->channel))
 845                 return;
 846
 847         stor_device->open_sub_channel = false;
 848         /*
 849          * Request the host to create sub-channels.
 850          */
 851         memset(request, 0, sizeof(struct storvsc_cmd_request));
 852         init_completion(&request->wait_event);
 853         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 854         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 855         vstor_packet->sub_channel_count = num_sc;
 856
 857         ret = vmbus_sendpacket(device->channel, vstor_packet,
 858                                (sizeof(struct vstor_packet) -
 859                                vmscsi_size_delta),
 860                                (unsigned long)request,
 861                                VM_PKT_DATA_INBAND,
 862                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 863
 864         if (ret != 0)
 865                 return;
 866
 867         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 868         if (t == 0)
 869                 return;
 870
 871         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 872             vstor_packet->status != 0)
 873                 return;
 874
 875         /*
 876          * Now that we created the sub-channels, invoke the check; this
 877          * may trigger the callback.
 878          */
 879         stor_device->open_sub_channel = true;
 880         vmbus_are_subchannels_present(device->channel);
 881 }
 882
 883 static int storvsc_channel_init(struct hv_device *device)
 884 {
 885         struct storvsc_device *stor_device;
 886         struct storvsc_cmd_request *request;
 887         struct vstor_packet *vstor_packet;
 888         int ret, t;
 889         int max_chns;
 890         bool process_sub_channels = false;
 891
 892         stor_device = get_out_stor_device(device);
 893         if (!stor_device)
 894                 return -ENODEV;
 895
 896         request = &stor_device->init_request;
 897         vstor_packet = &request->vstor_packet;
 898
 899         /*
 900          * Now, initiate the vsc/vsp initialization protocol on the open
 901          * channel
 902          */
 903         memset(request, 0, sizeof(struct storvsc_cmd_request));
 904         init_completion(&request->wait_event);
 905         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 906         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 907
 908         ret = vmbus_sendpacket(device->channel, vstor_packet,
 909                                (sizeof(struct vstor_packet) -
 910                                vmscsi_size_delta),
 911                                (unsigned long)request,
 912                                VM_PKT_DATA_INBAND,
 913                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 914         if (ret != 0)
 915                 goto cleanup;
 916
 917         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 918         if (t == 0) {
 919                 ret = -ETIMEDOUT;
 920                 goto cleanup;
 921         }
 922
 923         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 924             vstor_packet->status != 0)
 925                 goto cleanup;
 926
 927
 928         /* reuse the packet for version range supported */
 929         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 930         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 931         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 932
 933         vstor_packet->version.major_minor =
 934                 storvsc_get_version(vmstor_current_major, vmstor_current_minor);
 935
 936         /*
 937          * The revision number is only used in Windows; set it to 0.
 938          */
 939         vstor_packet->version.revision = 0;
 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         if (ret != 0)
 948                 goto cleanup;
 949
 950         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 951         if (t == 0) {
 952                 ret = -ETIMEDOUT;
 953                 goto cleanup;
 954         }
 955
 956         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 957             vstor_packet->status != 0)
 958                 goto cleanup;
 959
 960
 961         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 962         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 963         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 964
 965         ret = vmbus_sendpacket(device->channel, vstor_packet,
 966                                (sizeof(struct vstor_packet) -
 967                                 vmscsi_size_delta),
 968                                (unsigned long)request,
 969                                VM_PKT_DATA_INBAND,
 970                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 971
 972         if (ret != 0)
 973                 goto cleanup;
 974
 975         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 976         if (t == 0) {
 977                 ret = -ETIMEDOUT;
 978                 goto cleanup;
 979         }
 980
 981         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 982             vstor_packet->status != 0)
 983                 goto cleanup;
 984
 985         /*
 986          * Check to see if multi-channel support is there.
 987          * Hosts that implement protocol version of 5.1 and above
 988          * support multi-channel.
 989          */
 990         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 991         if ((vmbus_proto_version != VERSION_WIN7) &&
 992            (vmbus_proto_version != VERSION_WS2008))  {
 993                 if (vstor_packet->storage_channel_properties.flags &
 994                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 995                         process_sub_channels = true;
 996         }
 997         stor_device->max_transfer_bytes =
 998                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 999
1000         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1001         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
1002         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1003
1004         ret = vmbus_sendpacket(device->channel, vstor_packet,
1005                                (sizeof(struct vstor_packet) -
1006                                 vmscsi_size_delta),
1007                                (unsigned long)request,
1008                                VM_PKT_DATA_INBAND,
1009                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1010
1011         if (ret != 0)
1012                 goto cleanup;
1013
1014         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1015         if (t == 0) {
1016                 ret = -ETIMEDOUT;
1017                 goto cleanup;
1018         }
1019
1020         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
1021             vstor_packet->status != 0)
1022                 goto cleanup;
1023
1024         if (process_sub_channels)
1025                 handle_multichannel_storage(device, max_chns);
1026
1027
1028 cleanup:
1029         return ret;
1030 }
1031
1032 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1033                                 struct scsi_cmnd *scmnd,
1034                                 struct Scsi_Host *host,
1035                                 u8 asc, u8 ascq)
1036 {
1037         struct storvsc_scan_work *wrk;
1038         void (*process_err_fn)(struct work_struct *work);
1039         bool do_work = false;
1040
1041         switch (vm_srb->srb_status) {
1042         case SRB_STATUS_ERROR:
1043                 /*
1044                  * If there is an error; offline the device since all
1045                  * error recovery strategies would have already been
1046                  * deployed on the host side. However, if the command
1047                  * were a pass-through command deal with it appropriately.
1048                  */
1049                 switch (scmnd->cmnd[0]) {
1050                 case ATA_16:
1051                 case ATA_12:
1052                         set_host_byte(scmnd, DID_PASSTHROUGH);
1053                         break;
1054                 /*
1055                  * On Some Windows hosts TEST_UNIT_READY command can return
1056                  * SRB_STATUS_ERROR, let the upper level code deal with it
1057                  * based on the sense information.
1058                  */
1059                 case TEST_UNIT_READY:
1060                         break;
1061                 default:
1062                         set_host_byte(scmnd, DID_TARGET_FAILURE);
1063                 }
1064                 break;
1065         case SRB_STATUS_INVALID_LUN:
1066                 do_work = true;
1067                 process_err_fn = storvsc_remove_lun;
1068                 break;
1069         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
1070                 if ((asc == 0x2a) && (ascq == 0x9)) {
1071                         do_work = true;
1072                         process_err_fn = storvsc_device_scan;
1073                         /*
1074                          * Retry the I/O that trigerred this.
1075                          */
1076                         set_host_byte(scmnd, DID_REQUEUE);
1077                 }
1078                 break;
1079         }
1080
1081         if (!do_work)
1082                 return;
1083
1084         /*
1085          * We need to schedule work to process this error; schedule it.
1086          */
1087         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1088         if (!wrk) {
1089                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1090                 return;
1091         }
1092
1093         wrk->host = host;
1094         wrk->lun = vm_srb->lun;
1095         INIT_WORK(&wrk->work, process_err_fn);
1096         schedule_work(&wrk->work);
1097 }
1098
1099
1100 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
1101 {
1102         struct scsi_cmnd *scmnd = cmd_request->cmd;
1103         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1104         struct scsi_sense_hdr sense_hdr;
1105         struct vmscsi_request *vm_srb;
1106         struct Scsi_Host *host;
1107         struct storvsc_device *stor_dev;
1108         struct hv_device *dev = host_dev->dev;
1109         u32 payload_sz = cmd_request->payload_sz;
1110         void *payload = cmd_request->payload;
1111
1112         stor_dev = get_in_stor_device(dev);
1113         host = stor_dev->host;
1114
1115         vm_srb = &cmd_request->vstor_packet.vm_srb;
1116         if (cmd_request->bounce_sgl_count) {
1117                 if (vm_srb->data_in == READ_TYPE)
1118                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1119                                         cmd_request->bounce_sgl,
1120                                         scsi_sg_count(scmnd),
1121                                         cmd_request->bounce_sgl_count);
1122                 destroy_bounce_buffer(cmd_request->bounce_sgl,
1123                                         cmd_request->bounce_sgl_count);
1124         }
1125
1126         scmnd->result = vm_srb->scsi_status;
1127
1128         if (scmnd->result) {
1129                 if (scsi_normalize_sense(scmnd->sense_buffer,
1130                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1131                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1132                                              &sense_hdr);
1133         }
1134
1135         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
1136                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1137                                          sense_hdr.ascq);
1138
1139         scsi_set_resid(scmnd,
1140                 cmd_request->payload->range.len -
1141                 vm_srb->data_transfer_length);
1142
1143         scmnd->scsi_done(scmnd);
1144
1145         if (payload_sz >
1146                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1147                 kfree(payload);
1148 }
1149
1150 static void storvsc_on_io_completion(struct hv_device *device,
1151                                   struct vstor_packet *vstor_packet,
1152                                   struct storvsc_cmd_request *request)
1153 {
1154         struct storvsc_device *stor_device;
1155         struct vstor_packet *stor_pkt;
1156
1157         stor_device = hv_get_drvdata(device);
1158         stor_pkt = &request->vstor_packet;
1159
1160         /*
1161          * The current SCSI handling on the host side does
1162          * not correctly handle:
1163          * INQUIRY command with page code parameter set to 0x80
1164          * MODE_SENSE command with cmd[2] == 0x1c
1165          *
1166          * Setup srb and scsi status so this won't be fatal.
1167          * We do this so we can distinguish truly fatal failues
1168          * (srb status == 0x4) and off-line the device in that case.
1169          */
1170
1171         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1172            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1173                 vstor_packet->vm_srb.scsi_status = 0;
1174                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1175         }
1176
1177
1178         /* Copy over the status...etc */
1179         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1180         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1181         stor_pkt->vm_srb.sense_info_length =
1182         vstor_packet->vm_srb.sense_info_length;
1183
1184
1185         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1186                 /* CHECK_CONDITION */
1187                 if (vstor_packet->vm_srb.srb_status &
1188                         SRB_STATUS_AUTOSENSE_VALID) {
1189                         /* autosense data available */
1190
1191                         memcpy(request->cmd->sense_buffer,
1192                                vstor_packet->vm_srb.sense_data,
1193                                vstor_packet->vm_srb.sense_info_length);
1194
1195                 }
1196         }
1197
1198         stor_pkt->vm_srb.data_transfer_length =
1199         vstor_packet->vm_srb.data_transfer_length;
1200
1201         storvsc_command_completion(request);
1202
1203         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1204                 stor_device->drain_notify)
1205                 wake_up(&stor_device->waiting_to_drain);
1206
1207
1208 }
1209
1210 static void storvsc_on_receive(struct hv_device *device,
1211                              struct vstor_packet *vstor_packet,
1212                              struct storvsc_cmd_request *request)
1213 {
1214         struct storvsc_scan_work *work;
1215         struct storvsc_device *stor_device;
1216
1217         switch (vstor_packet->operation) {
1218         case VSTOR_OPERATION_COMPLETE_IO:
1219                 storvsc_on_io_completion(device, vstor_packet, request);
1220                 break;
1221
1222         case VSTOR_OPERATION_REMOVE_DEVICE:
1223         case VSTOR_OPERATION_ENUMERATE_BUS:
1224                 stor_device = get_in_stor_device(device);
1225                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1226                 if (!work)
1227                         return;
1228
1229                 INIT_WORK(&work->work, storvsc_host_scan);
1230                 work->host = stor_device->host;
1231                 schedule_work(&work->work);
1232                 break;
1233
1234         default:
1235                 break;
1236         }
1237 }
1238
1239 static void storvsc_on_channel_callback(void *context)
1240 {
1241         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1242         struct hv_device *device;
1243         struct storvsc_device *stor_device;
1244         u32 bytes_recvd;
1245         u64 request_id;
1246         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1247         struct storvsc_cmd_request *request;
1248         int ret;
1249
1250         if (channel->primary_channel != NULL)
1251                 device = channel->primary_channel->device_obj;
1252         else
1253                 device = channel->device_obj;
1254
1255         stor_device = get_in_stor_device(device);
1256         if (!stor_device)
1257                 return;
1258
1259         do {
1260                 ret = vmbus_recvpacket(channel, packet,
1261                                        ALIGN((sizeof(struct vstor_packet) -
1262                                              vmscsi_size_delta), 8),
1263                                        &bytes_recvd, &request_id);
1264                 if (ret == 0 && bytes_recvd > 0) {
1265
1266                         request = (struct storvsc_cmd_request *)
1267                                         (unsigned long)request_id;
1268
1269                         if ((request == &stor_device->init_request) ||
1270                             (request == &stor_device->reset_request)) {
1271
1272                                 memcpy(&request->vstor_packet, packet,
1273                                        (sizeof(struct vstor_packet) -
1274                                         vmscsi_size_delta));
1275                                 complete(&request->wait_event);
1276                         } else {
1277                                 storvsc_on_receive(device,
1278                                                 (struct vstor_packet *)packet,
1279                                                 request);
1280                         }
1281                 } else {
1282                         break;
1283                 }
1284         } while (1);
1285
1286         return;
1287 }
1288
1289 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1290 {
1291         struct vmstorage_channel_properties props;
1292         int ret;
1293
1294         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1295
1296         ret = vmbus_open(device->channel,
1297                          ring_size,
1298                          ring_size,
1299                          (void *)&props,
1300                          sizeof(struct vmstorage_channel_properties),
1301                          storvsc_on_channel_callback, device->channel);
1302
1303         if (ret != 0)
1304                 return ret;
1305
1306         ret = storvsc_channel_init(device);
1307
1308         return ret;
1309 }
1310
1311 static int storvsc_dev_remove(struct hv_device *device)
1312 {
1313         struct storvsc_device *stor_device;
1314         unsigned long flags;
1315
1316         stor_device = hv_get_drvdata(device);
1317
1318         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1319         stor_device->destroy = true;
1320         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1321
1322         /*
1323          * At this point, all outbound traffic should be disable. We
1324          * only allow inbound traffic (responses) to proceed so that
1325          * outstanding requests can be completed.
1326          */
1327
1328         storvsc_wait_to_drain(stor_device);
1329
1330         /*
1331          * Since we have already drained, we don't need to busy wait
1332          * as was done in final_release_stor_device()
1333          * Note that we cannot set the ext pointer to NULL until
1334          * we have drained - to drain the outgoing packets, we need to
1335          * allow incoming packets.
1336          */
1337         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1338         hv_set_drvdata(device, NULL);
1339         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1340
1341         /* Close the channel */
1342         vmbus_close(device->channel);
1343
1344         kfree(stor_device);
1345         return 0;
1346 }
1347
1348 static int storvsc_do_io(struct hv_device *device,
1349                          struct storvsc_cmd_request *request)
1350 {
1351         struct storvsc_device *stor_device;
1352         struct vstor_packet *vstor_packet;
1353         struct vmbus_channel *outgoing_channel;
1354         int ret = 0;
1355
1356         vstor_packet = &request->vstor_packet;
1357         stor_device = get_out_stor_device(device);
1358
1359         if (!stor_device)
1360                 return -ENODEV;
1361
1362
1363         request->device  = device;
1364         /*
1365          * Select an an appropriate channel to send the request out.
1366          */
1367
1368         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1369
1370
1371         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1372
1373         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1374                                         vmscsi_size_delta);
1375
1376
1377         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1378
1379
1380         vstor_packet->vm_srb.data_transfer_length =
1381         request->payload->range.len;
1382
1383         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1384
1385         if (request->payload->range.len) {
1386
1387                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1388                                 request->payload, request->payload_sz,
1389                                 vstor_packet,
1390                                 (sizeof(struct vstor_packet) -
1391                                 vmscsi_size_delta),
1392                                 (unsigned long)request);
1393         } else {
1394                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1395                                (sizeof(struct vstor_packet) -
1396                                 vmscsi_size_delta),
1397                                (unsigned long)request,
1398                                VM_PKT_DATA_INBAND,
1399                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1400         }
1401
1402         if (ret != 0)
1403                 return ret;
1404
1405         atomic_inc(&stor_device->num_outstanding_req);
1406
1407         return ret;
1408 }
1409
1410 static int storvsc_device_configure(struct scsi_device *sdevice)
1411 {
1412
1413         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1414
1415         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1416
1417         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1418
1419         sdevice->no_write_same = 1;
1420
1421         /*
1422          * Add blist flags to permit the reading of the VPD pages even when
1423          * the target may claim SPC-2 compliance. MSFT targets currently
1424          * claim SPC-2 compliance while they implement post SPC-2 features.
1425          * With this patch we can correctly handle WRITE_SAME_16 issues.
1426          */
1427         sdevice->sdev_bflags |= msft_blist_flags;
1428
1429         /*
1430          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1431          * if the device is a MSFT virtual device.
1432          */
1433         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1434                 switch (vmbus_proto_version) {
1435                 case VERSION_WIN8:
1436                 case VERSION_WIN8_1:
1437                         sdevice->scsi_level = SCSI_SPC_3;
1438                         break;
1439                 }
1440         }
1441
1442         return 0;
1443 }
1444
1445 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1446                            sector_t capacity, int *info)
1447 {
1448         sector_t nsect = capacity;
1449         sector_t cylinders = nsect;
1450         int heads, sectors_pt;
1451
1452         /*
1453          * We are making up these values; let us keep it simple.
1454          */
1455         heads = 0xff;
1456         sectors_pt = 0x3f;      /* Sectors per track */
1457         sector_div(cylinders, heads * sectors_pt);
1458         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1459                 cylinders = 0xffff;
1460
1461         info[0] = heads;
1462         info[1] = sectors_pt;
1463         info[2] = (int)cylinders;
1464
1465         return 0;
1466 }
1467
1468 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1469 {
1470         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1471         struct hv_device *device = host_dev->dev;
1472
1473         struct storvsc_device *stor_device;
1474         struct storvsc_cmd_request *request;
1475         struct vstor_packet *vstor_packet;
1476         int ret, t;
1477
1478
1479         stor_device = get_out_stor_device(device);
1480         if (!stor_device)
1481                 return FAILED;
1482
1483         request = &stor_device->reset_request;
1484         vstor_packet = &request->vstor_packet;
1485
1486         init_completion(&request->wait_event);
1487
1488         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1489         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1490         vstor_packet->vm_srb.path_id = stor_device->path_id;
1491
1492         ret = vmbus_sendpacket(device->channel, vstor_packet,
1493                                (sizeof(struct vstor_packet) -
1494                                 vmscsi_size_delta),
1495                                (unsigned long)&stor_device->reset_request,
1496                                VM_PKT_DATA_INBAND,
1497                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1498         if (ret != 0)
1499                 return FAILED;
1500
1501         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1502         if (t == 0)
1503                 return TIMEOUT_ERROR;
1504
1505
1506         /*
1507          * At this point, all outstanding requests in the adapter
1508          * should have been flushed out and return to us
1509          * There is a potential race here where the host may be in
1510          * the process of responding when we return from here.
1511          * Just wait for all in-transit packets to be accounted for
1512          * before we return from here.
1513          */
1514         storvsc_wait_to_drain(stor_device);
1515
1516         return SUCCESS;
1517 }
1518
1519 /*
1520  * The host guarantees to respond to each command, although I/O latencies might
1521  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1522  * chance to perform EH.
1523  */
1524 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1525 {
1526         return BLK_EH_RESET_TIMER;
1527 }
1528
1529 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1530 {
1531         bool allowed = true;
1532         u8 scsi_op = scmnd->cmnd[0];
1533
1534         switch (scsi_op) {
1535         /* the host does not handle WRITE_SAME, log accident usage */
1536         case WRITE_SAME:
1537         /*
1538          * smartd sends this command and the host does not handle
1539          * this. So, don't send it.
1540          */
1541         case SET_WINDOW:
1542                 scmnd->result = ILLEGAL_REQUEST << 16;
1543                 allowed = false;
1544                 break;
1545         default:
1546                 break;
1547         }
1548         return allowed;
1549 }
1550
1551 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1552 {
1553         int ret;
1554         struct hv_host_device *host_dev = shost_priv(host);
1555         struct hv_device *dev = host_dev->dev;
1556         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1557         int i;
1558         struct scatterlist *sgl;
1559         unsigned int sg_count = 0;
1560         struct vmscsi_request *vm_srb;
1561         struct scatterlist *cur_sgl;
1562         struct vmbus_packet_mpb_array  *payload;
1563         u32 payload_sz;
1564         u32 length;
1565
1566         if (vmstor_current_major <= VMSTOR_WIN8_MAJOR) {
1567                 /*
1568                  * On legacy hosts filter unimplemented commands.
1569                  * Future hosts are expected to correctly handle
1570                  * unsupported commands. Furthermore, it is
1571                  * possible that some of the currently
1572                  * unsupported commands maybe supported in
1573                  * future versions of the host.
1574                  */
1575                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1576                         scmnd->scsi_done(scmnd);
1577                         return 0;
1578                 }
1579         }
1580
1581         /* Setup the cmd request */
1582         cmd_request->cmd = scmnd;
1583
1584         vm_srb = &cmd_request->vstor_packet.vm_srb;
1585         vm_srb->win8_extension.time_out_value = 60;
1586
1587         vm_srb->win8_extension.srb_flags |=
1588                 (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1589                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1590
1591         /* Build the SRB */
1592         switch (scmnd->sc_data_direction) {
1593         case DMA_TO_DEVICE:
1594                 vm_srb->data_in = WRITE_TYPE;
1595                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1596                 break;
1597         case DMA_FROM_DEVICE:
1598                 vm_srb->data_in = READ_TYPE;
1599                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1600                 break;
1601         default:
1602                 vm_srb->data_in = UNKNOWN_TYPE;
1603                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1604                 break;
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         switch (vmbus_proto_version) {
1762         case VERSION_WS2008:
1763         case VERSION_WIN7:
1764                 sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
1765                 vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1766                 vmstor_current_major = VMSTOR_WIN7_MAJOR;
1767                 vmstor_current_minor = VMSTOR_WIN7_MINOR;
1768                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1769                 max_targets = STORVSC_IDE_MAX_TARGETS;
1770                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1771                 break;
1772         default:
1773                 sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
1774                 vmscsi_size_delta = 0;
1775                 vmstor_current_major = VMSTOR_WIN8_MAJOR;
1776                 vmstor_current_minor = VMSTOR_WIN8_MINOR;
1777                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1778                 max_targets = STORVSC_MAX_TARGETS;
1779                 max_channels = STORVSC_MAX_CHANNELS;
1780                 /*
1781                  * On Windows8 and above, we support sub-channels for storage.
1782                  * The number of sub-channels offerred is based on the number of
1783                  * VCPUs in the guest.
1784                  */
1785                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1786                 break;
1787         }
1788
1789         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1790                                  (max_sub_channels + 1));
1791
1792         host = scsi_host_alloc(&scsi_driver,
1793                                sizeof(struct hv_host_device));
1794         if (!host)
1795                 return -ENOMEM;
1796
1797         host_dev = shost_priv(host);
1798         memset(host_dev, 0, sizeof(struct hv_host_device));
1799
1800         host_dev->port = host->host_no;
1801         host_dev->dev = device;
1802
1803
1804         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1805         if (!stor_device) {
1806                 ret = -ENOMEM;
1807                 goto err_out0;
1808         }
1809
1810         stor_device->destroy = false;
1811         stor_device->open_sub_channel = false;
1812         init_waitqueue_head(&stor_device->waiting_to_drain);
1813         stor_device->device = device;
1814         stor_device->host = host;
1815         hv_set_drvdata(device, stor_device);
1816
1817         stor_device->port_number = host->host_no;
1818         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1819         if (ret)
1820                 goto err_out1;
1821
1822         host_dev->path = stor_device->path_id;
1823         host_dev->target = stor_device->target_id;
1824
1825         switch (dev_id->driver_data) {
1826         case SFC_GUID:
1827                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1828                 host->max_id = STORVSC_FC_MAX_TARGETS;
1829                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1830                 break;
1831
1832         case SCSI_GUID:
1833                 host->max_lun = max_luns_per_target;
1834                 host->max_id = max_targets;
1835                 host->max_channel = max_channels - 1;
1836                 break;
1837
1838         default:
1839                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1840                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1841                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1842                 break;
1843         }
1844         /* max cmd length */
1845         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1846
1847         /*
1848          * set the table size based on the info we got
1849          * from the host.
1850          */
1851         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1852
1853         /* Register the HBA and start the scsi bus scan */
1854         ret = scsi_add_host(host, &device->device);
1855         if (ret != 0)
1856                 goto err_out2;
1857
1858         if (!dev_is_ide) {
1859                 scsi_scan_host(host);
1860         } else {
1861                 target = (device->dev_instance.b[5] << 8 |
1862                          device->dev_instance.b[4]);
1863                 ret = scsi_add_device(host, 0, target, 0);
1864                 if (ret) {
1865                         scsi_remove_host(host);
1866                         goto err_out2;
1867                 }
1868         }
1869         return 0;
1870
1871 err_out2:
1872         /*
1873          * Once we have connected with the host, we would need to
1874          * to invoke storvsc_dev_remove() to rollback this state and
1875          * this call also frees up the stor_device; hence the jump around
1876          * err_out1 label.
1877          */
1878         storvsc_dev_remove(device);
1879         goto err_out0;
1880
1881 err_out1:
1882         kfree(stor_device);
1883
1884 err_out0:
1885         scsi_host_put(host);
1886         return ret;
1887 }
1888
1889 static int storvsc_remove(struct hv_device *dev)
1890 {
1891         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1892         struct Scsi_Host *host = stor_device->host;
1893
1894         scsi_remove_host(host);
1895         storvsc_dev_remove(dev);
1896         scsi_host_put(host);
1897
1898         return 0;
1899 }
1900
1901 static struct hv_driver storvsc_drv = {
1902         .name = KBUILD_MODNAME,
1903         .id_table = id_table,
1904         .probe = storvsc_probe,
1905         .remove = storvsc_remove,
1906 };
1907
1908 static int __init storvsc_drv_init(void)
1909 {
1910
1911         /*
1912          * Divide the ring buffer data size (which is 1 page less
1913          * than the ring buffer size since that page is reserved for
1914          * the ring buffer indices) by the max request size (which is
1915          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1916          */
1917         max_outstanding_req_per_channel =
1918                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1919                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1920                 sizeof(struct vstor_packet) + sizeof(u64) -
1921                 vmscsi_size_delta,
1922                 sizeof(u64)));
1923
1924         return vmbus_driver_register(&storvsc_drv);
1925 }
1926
1927 static void __exit storvsc_drv_exit(void)
1928 {
1929         vmbus_driver_unregister(&storvsc_drv);
1930 }
1931
1932 MODULE_LICENSE("GPL");
1933 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1934 module_init(storvsc_drv_init);
1935 module_exit(storvsc_drv_exit);