drivers/scsi/storvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *   K. Y. Srinivasan <kys@microsoft.com>
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/wait.h>
  25 #include <linux/sched.h>
  26 #include <linux/completion.h>
  27 #include <linux/string.h>
  28 #include <linux/mm.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/device.h>
  34 #include <linux/hyperv.h>
  35 #include <linux/mempool.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_tcq.h>
  41 #include <scsi/scsi_eh.h>
  42 #include <scsi/scsi_devinfo.h>
  43 #include <scsi/scsi_dbg.h>
  44
  45 /*
  46  * All wire protocol details (storage protocol between the guest and the host)
  47  * are consolidated here.
  48  *
  49  * Begin protocol definitions.
  50  */
  51
  52 /*
  53  * Version history:
  54  * V1 Beta: 0.1
  55  * V1 RC < 2008/1/31: 1.0
  56  * V1 RC > 2008/1/31:  2.0
  57  * Win7: 4.2
  58  * 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
 312 /*
 313  * We setup a mempool to allocate request structures for this driver
 314  * on a per-lun basis. The following define specifies the number of
 315  * elements in the pool.
 316  */
 317
 318 #define STORVSC_MIN_BUF_NR                              64
 319 static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
 320
 321 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 322 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 323
 324 /*
 325  * Timeout in seconds for all devices managed by this driver.
 326  */
 327 static int storvsc_timeout = 180;
 328
 329 #define STORVSC_MAX_IO_REQUESTS                         200
 330
 331 static void storvsc_on_channel_callback(void *context);
 332
 333 /*
 334  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
 335  * reality, the path/target is not used (ie always set to 0) so our
 336  * scsi host adapter essentially has 1 bus with 1 target that contains
 337  * up to 256 luns.
 338  */
 339 #define STORVSC_MAX_LUNS_PER_TARGET                     64
 340 #define STORVSC_MAX_TARGETS                             1
 341 #define STORVSC_MAX_CHANNELS                            1
 342
 343
 344
 345 struct storvsc_cmd_request {
 346         struct list_head entry;
 347         struct scsi_cmnd *cmd;
 348
 349         unsigned int bounce_sgl_count;
 350         struct scatterlist *bounce_sgl;
 351
 352         struct hv_device *device;
 353
 354         /* Synchronize the request/response if needed */
 355         struct completion wait_event;
 356
 357         unsigned char *sense_buffer;
 358         struct hv_multipage_buffer data_buffer;
 359         struct vstor_packet vstor_packet;
 360 };
 361
 362
 363 /* A storvsc device is a device object that contains a vmbus channel */
 364 struct storvsc_device {
 365         struct hv_device *device;
 366
 367         bool     destroy;
 368         bool     drain_notify;
 369         bool     open_sub_channel;
 370         atomic_t num_outstanding_req;
 371         struct Scsi_Host *host;
 372
 373         wait_queue_head_t waiting_to_drain;
 374
 375         /*
 376          * Each unique Port/Path/Target represents 1 channel ie scsi
 377          * controller. In reality, the pathid, targetid is always 0
 378          * and the port is set by us
 379          */
 380         unsigned int port_number;
 381         unsigned char path_id;
 382         unsigned char target_id;
 383
 384         /* Used for vsc/vsp channel reset process */
 385         struct storvsc_cmd_request init_request;
 386         struct storvsc_cmd_request reset_request;
 387 };
 388
 389 struct stor_mem_pools {
 390         struct kmem_cache *request_pool;
 391         mempool_t *request_mempool;
 392 };
 393
 394 struct hv_host_device {
 395         struct hv_device *dev;
 396         unsigned int port;
 397         unsigned char path;
 398         unsigned char target;
 399 };
 400
 401 struct storvsc_scan_work {
 402         struct work_struct work;
 403         struct Scsi_Host *host;
 404         uint lun;
 405 };
 406
 407 static void storvsc_device_scan(struct work_struct *work)
 408 {
 409         struct storvsc_scan_work *wrk;
 410         uint lun;
 411         struct scsi_device *sdev;
 412
 413         wrk = container_of(work, struct storvsc_scan_work, work);
 414         lun = wrk->lun;
 415
 416         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 417         if (!sdev)
 418                 goto done;
 419         scsi_rescan_device(&sdev->sdev_gendev);
 420         scsi_device_put(sdev);
 421
 422 done:
 423         kfree(wrk);
 424 }
 425
 426 static void storvsc_bus_scan(struct work_struct *work)
 427 {
 428         struct storvsc_scan_work *wrk;
 429         int id, order_id;
 430
 431         wrk = container_of(work, struct storvsc_scan_work, work);
 432         for (id = 0; id < wrk->host->max_id; ++id) {
 433                 if (wrk->host->reverse_ordering)
 434                         order_id = wrk->host->max_id - id - 1;
 435                 else
 436                         order_id = id;
 437
 438                 scsi_scan_target(&wrk->host->shost_gendev, 0,
 439                                 order_id, SCAN_WILD_CARD, 1);
 440         }
 441         kfree(wrk);
 442 }
 443
 444 static void storvsc_remove_lun(struct work_struct *work)
 445 {
 446         struct storvsc_scan_work *wrk;
 447         struct scsi_device *sdev;
 448
 449         wrk = container_of(work, struct storvsc_scan_work, work);
 450         if (!scsi_host_get(wrk->host))
 451                 goto done;
 452
 453         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 454
 455         if (sdev) {
 456                 scsi_remove_device(sdev);
 457                 scsi_device_put(sdev);
 458         }
 459         scsi_host_put(wrk->host);
 460
 461 done:
 462         kfree(wrk);
 463 }
 464
 465 /*
 466  * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 467  * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 468  */
 469
 470 static inline u16 storvsc_get_version(u8 major, u8 minor)
 471 {
 472         u16 version;
 473
 474         version = ((major << 8) | minor);
 475         return version;
 476 }
 477
 478 /*
 479  * We can get incoming messages from the host that are not in response to
 480  * messages that we have sent out. An example of this would be messages
 481  * received by the guest to notify dynamic addition/removal of LUNs. To
 482  * deal with potential race conditions where the driver may be in the
 483  * midst of being unloaded when we might receive an unsolicited message
 484  * from the host, we have implemented a mechanism to gurantee sequential
 485  * consistency:
 486  *
 487  * 1) Once the device is marked as being destroyed, we will fail all
 488  *    outgoing messages.
 489  * 2) We permit incoming messages when the device is being destroyed,
 490  *    only to properly account for messages already sent out.
 491  */
 492
 493 static inline struct storvsc_device *get_out_stor_device(
 494                                         struct hv_device *device)
 495 {
 496         struct storvsc_device *stor_device;
 497
 498         stor_device = hv_get_drvdata(device);
 499
 500         if (stor_device && stor_device->destroy)
 501                 stor_device = NULL;
 502
 503         return stor_device;
 504 }
 505
 506
 507 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 508 {
 509         dev->drain_notify = true;
 510         wait_event(dev->waiting_to_drain,
 511                    atomic_read(&dev->num_outstanding_req) == 0);
 512         dev->drain_notify = false;
 513 }
 514
 515 static inline struct storvsc_device *get_in_stor_device(
 516                                         struct hv_device *device)
 517 {
 518         struct storvsc_device *stor_device;
 519
 520         stor_device = hv_get_drvdata(device);
 521
 522         if (!stor_device)
 523                 goto get_in_err;
 524
 525         /*
 526          * If the device is being destroyed; allow incoming
 527          * traffic only to cleanup outstanding requests.
 528          */
 529
 530         if (stor_device->destroy  &&
 531                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 532                 stor_device = NULL;
 533
 534 get_in_err:
 535         return stor_device;
 536
 537 }
 538
 539 static void destroy_bounce_buffer(struct scatterlist *sgl,
 540                                   unsigned int sg_count)
 541 {
 542         int i;
 543         struct page *page_buf;
 544
 545         for (i = 0; i < sg_count; i++) {
 546                 page_buf = sg_page((&sgl[i]));
 547                 if (page_buf != NULL)
 548                         __free_page(page_buf);
 549         }
 550
 551         kfree(sgl);
 552 }
 553
 554 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 555 {
 556         int i;
 557
 558         /* No need to check */
 559         if (sg_count < 2)
 560                 return -1;
 561
 562         /* We have at least 2 sg entries */
 563         for (i = 0; i < sg_count; i++) {
 564                 if (i == 0) {
 565                         /* make sure 1st one does not have hole */
 566                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 567                                 return i;
 568                 } else if (i == sg_count - 1) {
 569                         /* make sure last one does not have hole */
 570                         if (sgl[i].offset != 0)
 571                                 return i;
 572                 } else {
 573                         /* make sure no hole in the middle */
 574                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 575                                 return i;
 576                 }
 577         }
 578         return -1;
 579 }
 580
 581 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 582                                                 unsigned int sg_count,
 583                                                 unsigned int len,
 584                                                 int write)
 585 {
 586         int i;
 587         int num_pages;
 588         struct scatterlist *bounce_sgl;
 589         struct page *page_buf;
 590         unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 591
 592         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 593
 594         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 595         if (!bounce_sgl)
 596                 return NULL;
 597
 598         sg_init_table(bounce_sgl, num_pages);
 599         for (i = 0; i < num_pages; i++) {
 600                 page_buf = alloc_page(GFP_ATOMIC);
 601                 if (!page_buf)
 602                         goto cleanup;
 603                 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 604         }
 605
 606         return bounce_sgl;
 607
 608 cleanup:
 609         destroy_bounce_buffer(bounce_sgl, num_pages);
 610         return NULL;
 611 }
 612
 613 /* Disgusting wrapper functions */
 614 static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
 615 {
 616         void *addr = kmap_atomic(sg_page(sgl + idx));
 617         return (unsigned long)addr;
 618 }
 619
 620 static inline void sg_kunmap_atomic(unsigned long addr)
 621 {
 622         kunmap_atomic((void *)addr);
 623 }
 624
 625
 626 /* Assume the original sgl has enough room */
 627 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 628                                             struct scatterlist *bounce_sgl,
 629                                             unsigned int orig_sgl_count,
 630                                             unsigned int bounce_sgl_count)
 631 {
 632         int i;
 633         int j = 0;
 634         unsigned long src, dest;
 635         unsigned int srclen, destlen, copylen;
 636         unsigned int total_copied = 0;
 637         unsigned long bounce_addr = 0;
 638         unsigned long dest_addr = 0;
 639         unsigned long flags;
 640
 641         local_irq_save(flags);
 642
 643         for (i = 0; i < orig_sgl_count; i++) {
 644                 dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 645                 dest = dest_addr;
 646                 destlen = orig_sgl[i].length;
 647
 648                 if (bounce_addr == 0)
 649                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 650
 651                 while (destlen) {
 652                         src = bounce_addr + bounce_sgl[j].offset;
 653                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 654
 655                         copylen = min(srclen, destlen);
 656                         memcpy((void *)dest, (void *)src, copylen);
 657
 658                         total_copied += copylen;
 659                         bounce_sgl[j].offset += copylen;
 660                         destlen -= copylen;
 661                         dest += copylen;
 662
 663                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 664                                 /* full */
 665                                 sg_kunmap_atomic(bounce_addr);
 666                                 j++;
 667
 668                                 /*
 669                                  * It is possible that the number of elements
 670                                  * in the bounce buffer may not be equal to
 671                                  * the number of elements in the original
 672                                  * scatter list. Handle this correctly.
 673                                  */
 674
 675                                 if (j == bounce_sgl_count) {
 676                                         /*
 677                                          * We are done; cleanup and return.
 678                                          */
 679                                         sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 680                                         local_irq_restore(flags);
 681                                         return total_copied;
 682                                 }
 683
 684                                 /* if we need to use another bounce buffer */
 685                                 if (destlen || i != orig_sgl_count - 1)
 686                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 687                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 688                                 /* unmap the last bounce that is < PAGE_SIZE */
 689                                 sg_kunmap_atomic(bounce_addr);
 690                         }
 691                 }
 692
 693                 sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 694         }
 695
 696         local_irq_restore(flags);
 697
 698         return total_copied;
 699 }
 700
 701 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 702 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 703                                           struct scatterlist *bounce_sgl,
 704                                           unsigned int orig_sgl_count)
 705 {
 706         int i;
 707         int j = 0;
 708         unsigned long src, dest;
 709         unsigned int srclen, destlen, copylen;
 710         unsigned int total_copied = 0;
 711         unsigned long bounce_addr = 0;
 712         unsigned long src_addr = 0;
 713         unsigned long flags;
 714
 715         local_irq_save(flags);
 716
 717         for (i = 0; i < orig_sgl_count; i++) {
 718                 src_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 719                 src = src_addr;
 720                 srclen = orig_sgl[i].length;
 721
 722                 if (bounce_addr == 0)
 723                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 724
 725                 while (srclen) {
 726                         /* assume bounce offset always == 0 */
 727                         dest = bounce_addr + bounce_sgl[j].length;
 728                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 729
 730                         copylen = min(srclen, destlen);
 731                         memcpy((void *)dest, (void *)src, copylen);
 732
 733                         total_copied += copylen;
 734                         bounce_sgl[j].length += copylen;
 735                         srclen -= copylen;
 736                         src += copylen;
 737
 738                         if (bounce_sgl[j].length == PAGE_SIZE) {
 739                                 /* full..move to next entry */
 740                                 sg_kunmap_atomic(bounce_addr);
 741                                 j++;
 742
 743                                 /* if we need to use another bounce buffer */
 744                                 if (srclen || i != orig_sgl_count - 1)
 745                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 746
 747                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 748                                 /* unmap the last bounce that is < PAGE_SIZE */
 749                                 sg_kunmap_atomic(bounce_addr);
 750                         }
 751                 }
 752
 753                 sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
 754         }
 755
 756         local_irq_restore(flags);
 757
 758         return total_copied;
 759 }
 760
 761 static void handle_sc_creation(struct vmbus_channel *new_sc)
 762 {
 763         struct hv_device *device = new_sc->primary_channel->device_obj;
 764         struct storvsc_device *stor_device;
 765         struct vmstorage_channel_properties props;
 766
 767         stor_device = get_out_stor_device(device);
 768         if (!stor_device)
 769                 return;
 770
 771         if (stor_device->open_sub_channel == false)
 772                 return;
 773
 774         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 775
 776         vmbus_open(new_sc,
 777                    storvsc_ringbuffer_size,
 778                    storvsc_ringbuffer_size,
 779                    (void *)&props,
 780                    sizeof(struct vmstorage_channel_properties),
 781                    storvsc_on_channel_callback, new_sc);
 782 }
 783
 784 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 785 {
 786         struct storvsc_device *stor_device;
 787         int num_cpus = num_online_cpus();
 788         int num_sc;
 789         struct storvsc_cmd_request *request;
 790         struct vstor_packet *vstor_packet;
 791         int ret, t;
 792
 793         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 794         stor_device = get_out_stor_device(device);
 795         if (!stor_device)
 796                 return;
 797
 798         request = &stor_device->init_request;
 799         vstor_packet = &request->vstor_packet;
 800
 801         stor_device->open_sub_channel = true;
 802         /*
 803          * Establish a handler for dealing with subchannels.
 804          */
 805         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 806
 807         /*
 808          * Check to see if sub-channels have already been created. This
 809          * can happen when this driver is re-loaded after unloading.
 810          */
 811
 812         if (vmbus_are_subchannels_present(device->channel))
 813                 return;
 814
 815         stor_device->open_sub_channel = false;
 816         /*
 817          * Request the host to create sub-channels.
 818          */
 819         memset(request, 0, sizeof(struct storvsc_cmd_request));
 820         init_completion(&request->wait_event);
 821         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 822         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 823         vstor_packet->sub_channel_count = num_sc;
 824
 825         ret = vmbus_sendpacket(device->channel, vstor_packet,
 826                                (sizeof(struct vstor_packet) -
 827                                vmscsi_size_delta),
 828                                (unsigned long)request,
 829                                VM_PKT_DATA_INBAND,
 830                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 831
 832         if (ret != 0)
 833                 return;
 834
 835         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 836         if (t == 0)
 837                 return;
 838
 839         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 840             vstor_packet->status != 0)
 841                 return;
 842
 843         /*
 844          * Now that we created the sub-channels, invoke the check; this
 845          * may trigger the callback.
 846          */
 847         stor_device->open_sub_channel = true;
 848         vmbus_are_subchannels_present(device->channel);
 849 }
 850
 851 static int storvsc_channel_init(struct hv_device *device)
 852 {
 853         struct storvsc_device *stor_device;
 854         struct storvsc_cmd_request *request;
 855         struct vstor_packet *vstor_packet;
 856         int ret, t;
 857         int max_chns;
 858         bool process_sub_channels = false;
 859
 860         stor_device = get_out_stor_device(device);
 861         if (!stor_device)
 862                 return -ENODEV;
 863
 864         request = &stor_device->init_request;
 865         vstor_packet = &request->vstor_packet;
 866
 867         /*
 868          * Now, initiate the vsc/vsp initialization protocol on the open
 869          * channel
 870          */
 871         memset(request, 0, sizeof(struct storvsc_cmd_request));
 872         init_completion(&request->wait_event);
 873         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 874         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 875
 876         ret = vmbus_sendpacket(device->channel, vstor_packet,
 877                                (sizeof(struct vstor_packet) -
 878                                vmscsi_size_delta),
 879                                (unsigned long)request,
 880                                VM_PKT_DATA_INBAND,
 881                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 882         if (ret != 0)
 883                 goto cleanup;
 884
 885         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 886         if (t == 0) {
 887                 ret = -ETIMEDOUT;
 888                 goto cleanup;
 889         }
 890
 891         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 892             vstor_packet->status != 0)
 893                 goto cleanup;
 894
 895
 896         /* reuse the packet for version range supported */
 897         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 898         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 899         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 900
 901         vstor_packet->version.major_minor =
 902                 storvsc_get_version(vmstor_current_major, vmstor_current_minor);
 903
 904         /*
 905          * The revision number is only used in Windows; set it to 0.
 906          */
 907         vstor_packet->version.revision = 0;
 908
 909         ret = vmbus_sendpacket(device->channel, vstor_packet,
 910                                (sizeof(struct vstor_packet) -
 911                                 vmscsi_size_delta),
 912                                (unsigned long)request,
 913                                VM_PKT_DATA_INBAND,
 914                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 915         if (ret != 0)
 916                 goto cleanup;
 917
 918         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 919         if (t == 0) {
 920                 ret = -ETIMEDOUT;
 921                 goto cleanup;
 922         }
 923
 924         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 925             vstor_packet->status != 0)
 926                 goto cleanup;
 927
 928
 929         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 930         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 931         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 932
 933         ret = vmbus_sendpacket(device->channel, vstor_packet,
 934                                (sizeof(struct vstor_packet) -
 935                                 vmscsi_size_delta),
 936                                (unsigned long)request,
 937                                VM_PKT_DATA_INBAND,
 938                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 939
 940         if (ret != 0)
 941                 goto cleanup;
 942
 943         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 944         if (t == 0) {
 945                 ret = -ETIMEDOUT;
 946                 goto cleanup;
 947         }
 948
 949         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 950             vstor_packet->status != 0)
 951                 goto cleanup;
 952
 953         /*
 954          * Check to see if multi-channel support is there.
 955          * Hosts that implement protocol version of 5.1 and above
 956          * support multi-channel.
 957          */
 958         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 959         if ((vmbus_proto_version != VERSION_WIN7) &&
 960            (vmbus_proto_version != VERSION_WS2008))  {
 961                 if (vstor_packet->storage_channel_properties.flags &
 962                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 963                         process_sub_channels = true;
 964         }
 965
 966         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 967         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 968         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 969
 970         ret = vmbus_sendpacket(device->channel, vstor_packet,
 971                                (sizeof(struct vstor_packet) -
 972                                 vmscsi_size_delta),
 973                                (unsigned long)request,
 974                                VM_PKT_DATA_INBAND,
 975                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 976
 977         if (ret != 0)
 978                 goto cleanup;
 979
 980         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 981         if (t == 0) {
 982                 ret = -ETIMEDOUT;
 983                 goto cleanup;
 984         }
 985
 986         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 987             vstor_packet->status != 0)
 988                 goto cleanup;
 989
 990         if (process_sub_channels)
 991                 handle_multichannel_storage(device, max_chns);
 992
 993
 994 cleanup:
 995         return ret;
 996 }
 997
 998 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 999                                 struct scsi_cmnd *scmnd,
1000                                 struct Scsi_Host *host,
1001                                 u8 asc, u8 ascq)
1002 {
1003         struct storvsc_scan_work *wrk;
1004         void (*process_err_fn)(struct work_struct *work);
1005         bool do_work = false;
1006
1007         switch (vm_srb->srb_status) {
1008         case SRB_STATUS_ERROR:
1009                 /*
1010                  * If there is an error; offline the device since all
1011                  * error recovery strategies would have already been
1012                  * deployed on the host side. However, if the command
1013                  * were a pass-through command deal with it appropriately.
1014                  */
1015                 switch (scmnd->cmnd[0]) {
1016                 case ATA_16:
1017                 case ATA_12:
1018                         set_host_byte(scmnd, DID_PASSTHROUGH);
1019                         break;
1020                 default:
1021                         set_host_byte(scmnd, DID_TARGET_FAILURE);
1022                 }
1023                 break;
1024         case SRB_STATUS_INVALID_LUN:
1025                 do_work = true;
1026                 process_err_fn = storvsc_remove_lun;
1027                 break;
1028         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
1029                 if ((asc == 0x2a) && (ascq == 0x9)) {
1030                         do_work = true;
1031                         process_err_fn = storvsc_device_scan;
1032                         /*
1033                          * Retry the I/O that trigerred this.
1034                          */
1035                         set_host_byte(scmnd, DID_REQUEUE);
1036                 }
1037                 break;
1038         }
1039
1040         if (!do_work)
1041                 return;
1042
1043         /*
1044          * We need to schedule work to process this error; schedule it.
1045          */
1046         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1047         if (!wrk) {
1048                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1049                 return;
1050         }
1051
1052         wrk->host = host;
1053         wrk->lun = vm_srb->lun;
1054         INIT_WORK(&wrk->work, process_err_fn);
1055         schedule_work(&wrk->work);
1056 }
1057
1058
1059 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
1060 {
1061         struct scsi_cmnd *scmnd = cmd_request->cmd;
1062         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1063         void (*scsi_done_fn)(struct scsi_cmnd *);
1064         struct scsi_sense_hdr sense_hdr;
1065         struct vmscsi_request *vm_srb;
1066         struct stor_mem_pools *memp = scmnd->device->hostdata;
1067         struct Scsi_Host *host;
1068         struct storvsc_device *stor_dev;
1069         struct hv_device *dev = host_dev->dev;
1070
1071         stor_dev = get_in_stor_device(dev);
1072         host = stor_dev->host;
1073
1074         vm_srb = &cmd_request->vstor_packet.vm_srb;
1075         if (cmd_request->bounce_sgl_count) {
1076                 if (vm_srb->data_in == READ_TYPE)
1077                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1078                                         cmd_request->bounce_sgl,
1079                                         scsi_sg_count(scmnd),
1080                                         cmd_request->bounce_sgl_count);
1081                 destroy_bounce_buffer(cmd_request->bounce_sgl,
1082                                         cmd_request->bounce_sgl_count);
1083         }
1084
1085         scmnd->result = vm_srb->scsi_status;
1086
1087         if (scmnd->result) {
1088                 if (scsi_normalize_sense(scmnd->sense_buffer,
1089                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1090                         scsi_print_sense_hdr("storvsc", &sense_hdr);
1091         }
1092
1093         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
1094                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1095                                          sense_hdr.ascq);
1096
1097         scsi_set_resid(scmnd,
1098                 cmd_request->data_buffer.len -
1099                 vm_srb->data_transfer_length);
1100
1101         scsi_done_fn = scmnd->scsi_done;
1102
1103         scmnd->host_scribble = NULL;
1104         scmnd->scsi_done = NULL;
1105
1106         scsi_done_fn(scmnd);
1107
1108         mempool_free(cmd_request, memp->request_mempool);
1109 }
1110
1111 static void storvsc_on_io_completion(struct hv_device *device,
1112                                   struct vstor_packet *vstor_packet,
1113                                   struct storvsc_cmd_request *request)
1114 {
1115         struct storvsc_device *stor_device;
1116         struct vstor_packet *stor_pkt;
1117
1118         stor_device = hv_get_drvdata(device);
1119         stor_pkt = &request->vstor_packet;
1120
1121         /*
1122          * The current SCSI handling on the host side does
1123          * not correctly handle:
1124          * INQUIRY command with page code parameter set to 0x80
1125          * MODE_SENSE command with cmd[2] == 0x1c
1126          *
1127          * Setup srb and scsi status so this won't be fatal.
1128          * We do this so we can distinguish truly fatal failues
1129          * (srb status == 0x4) and off-line the device in that case.
1130          */
1131
1132         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1133            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1134                 vstor_packet->vm_srb.scsi_status = 0;
1135                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1136         }
1137
1138
1139         /* Copy over the status...etc */
1140         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1141         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1142         stor_pkt->vm_srb.sense_info_length =
1143         vstor_packet->vm_srb.sense_info_length;
1144
1145         if (vstor_packet->vm_srb.scsi_status != 0 ||
1146                 vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS){
1147                 dev_warn(&device->device,
1148                          "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1149                          stor_pkt->vm_srb.cdb[0],
1150                          vstor_packet->vm_srb.scsi_status,
1151                          vstor_packet->vm_srb.srb_status);
1152         }
1153
1154         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1155                 /* CHECK_CONDITION */
1156                 if (vstor_packet->vm_srb.srb_status &
1157                         SRB_STATUS_AUTOSENSE_VALID) {
1158                         /* autosense data available */
1159                         dev_warn(&device->device,
1160                                  "stor pkt %p autosense data valid - len %d\n",
1161                                  request,
1162                                  vstor_packet->vm_srb.sense_info_length);
1163
1164                         memcpy(request->sense_buffer,
1165                                vstor_packet->vm_srb.sense_data,
1166                                vstor_packet->vm_srb.sense_info_length);
1167
1168                 }
1169         }
1170
1171         stor_pkt->vm_srb.data_transfer_length =
1172         vstor_packet->vm_srb.data_transfer_length;
1173
1174         storvsc_command_completion(request);
1175
1176         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1177                 stor_device->drain_notify)
1178                 wake_up(&stor_device->waiting_to_drain);
1179
1180
1181 }
1182
1183 static void storvsc_on_receive(struct hv_device *device,
1184                              struct vstor_packet *vstor_packet,
1185                              struct storvsc_cmd_request *request)
1186 {
1187         struct storvsc_scan_work *work;
1188         struct storvsc_device *stor_device;
1189
1190         switch (vstor_packet->operation) {
1191         case VSTOR_OPERATION_COMPLETE_IO:
1192                 storvsc_on_io_completion(device, vstor_packet, request);
1193                 break;
1194
1195         case VSTOR_OPERATION_REMOVE_DEVICE:
1196         case VSTOR_OPERATION_ENUMERATE_BUS:
1197                 stor_device = get_in_stor_device(device);
1198                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1199                 if (!work)
1200                         return;
1201
1202                 INIT_WORK(&work->work, storvsc_bus_scan);
1203                 work->host = stor_device->host;
1204                 schedule_work(&work->work);
1205                 break;
1206
1207         default:
1208                 break;
1209         }
1210 }
1211
1212 static void storvsc_on_channel_callback(void *context)
1213 {
1214         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1215         struct hv_device *device;
1216         struct storvsc_device *stor_device;
1217         u32 bytes_recvd;
1218         u64 request_id;
1219         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1220         struct storvsc_cmd_request *request;
1221         int ret;
1222
1223         if (channel->primary_channel != NULL)
1224                 device = channel->primary_channel->device_obj;
1225         else
1226                 device = channel->device_obj;
1227
1228         stor_device = get_in_stor_device(device);
1229         if (!stor_device)
1230                 return;
1231
1232         do {
1233                 ret = vmbus_recvpacket(channel, packet,
1234                                        ALIGN((sizeof(struct vstor_packet) -
1235                                              vmscsi_size_delta), 8),
1236                                        &bytes_recvd, &request_id);
1237                 if (ret == 0 && bytes_recvd > 0) {
1238
1239                         request = (struct storvsc_cmd_request *)
1240                                         (unsigned long)request_id;
1241
1242                         if ((request == &stor_device->init_request) ||
1243                             (request == &stor_device->reset_request)) {
1244
1245                                 memcpy(&request->vstor_packet, packet,
1246                                        (sizeof(struct vstor_packet) -
1247                                         vmscsi_size_delta));
1248                                 complete(&request->wait_event);
1249                         } else {
1250                                 storvsc_on_receive(device,
1251                                                 (struct vstor_packet *)packet,
1252                                                 request);
1253                         }
1254                 } else {
1255                         break;
1256                 }
1257         } while (1);
1258
1259         return;
1260 }
1261
1262 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1263 {
1264         struct vmstorage_channel_properties props;
1265         int ret;
1266
1267         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1268
1269         ret = vmbus_open(device->channel,
1270                          ring_size,
1271                          ring_size,
1272                          (void *)&props,
1273                          sizeof(struct vmstorage_channel_properties),
1274                          storvsc_on_channel_callback, device->channel);
1275
1276         if (ret != 0)
1277                 return ret;
1278
1279         ret = storvsc_channel_init(device);
1280
1281         return ret;
1282 }
1283
1284 static int storvsc_dev_remove(struct hv_device *device)
1285 {
1286         struct storvsc_device *stor_device;
1287         unsigned long flags;
1288
1289         stor_device = hv_get_drvdata(device);
1290
1291         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1292         stor_device->destroy = true;
1293         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1294
1295         /*
1296          * At this point, all outbound traffic should be disable. We
1297          * only allow inbound traffic (responses) to proceed so that
1298          * outstanding requests can be completed.
1299          */
1300
1301         storvsc_wait_to_drain(stor_device);
1302
1303         /*
1304          * Since we have already drained, we don't need to busy wait
1305          * as was done in final_release_stor_device()
1306          * Note that we cannot set the ext pointer to NULL until
1307          * we have drained - to drain the outgoing packets, we need to
1308          * allow incoming packets.
1309          */
1310         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1311         hv_set_drvdata(device, NULL);
1312         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1313
1314         /* Close the channel */
1315         vmbus_close(device->channel);
1316
1317         kfree(stor_device);
1318         return 0;
1319 }
1320
1321 static int storvsc_do_io(struct hv_device *device,
1322                               struct storvsc_cmd_request *request)
1323 {
1324         struct storvsc_device *stor_device;
1325         struct vstor_packet *vstor_packet;
1326         struct vmbus_channel *outgoing_channel;
1327         int ret = 0;
1328
1329         vstor_packet = &request->vstor_packet;
1330         stor_device = get_out_stor_device(device);
1331
1332         if (!stor_device)
1333                 return -ENODEV;
1334
1335
1336         request->device  = device;
1337         /*
1338          * Select an an appropriate channel to send the request out.
1339          */
1340
1341         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1342
1343
1344         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1345
1346         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1347                                         vmscsi_size_delta);
1348
1349
1350         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1351
1352
1353         vstor_packet->vm_srb.data_transfer_length =
1354         request->data_buffer.len;
1355
1356         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1357
1358         if (request->data_buffer.len) {
1359                 ret = vmbus_sendpacket_multipagebuffer(outgoing_channel,
1360                                 &request->data_buffer,
1361                                 vstor_packet,
1362                                 (sizeof(struct vstor_packet) -
1363                                 vmscsi_size_delta),
1364                                 (unsigned long)request);
1365         } else {
1366                 ret = vmbus_sendpacket(device->channel, vstor_packet,
1367                                (sizeof(struct vstor_packet) -
1368                                 vmscsi_size_delta),
1369                                (unsigned long)request,
1370                                VM_PKT_DATA_INBAND,
1371                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1372         }
1373
1374         if (ret != 0)
1375                 return ret;
1376
1377         atomic_inc(&stor_device->num_outstanding_req);
1378
1379         return ret;
1380 }
1381
1382 static int storvsc_device_alloc(struct scsi_device *sdevice)
1383 {
1384         struct stor_mem_pools *memp;
1385         int number = STORVSC_MIN_BUF_NR;
1386
1387         memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
1388         if (!memp)
1389                 return -ENOMEM;
1390
1391         memp->request_pool =
1392                 kmem_cache_create(dev_name(&sdevice->sdev_dev),
1393                                 sizeof(struct storvsc_cmd_request), 0,
1394                                 SLAB_HWCACHE_ALIGN, NULL);
1395
1396         if (!memp->request_pool)
1397                 goto err0;
1398
1399         memp->request_mempool = mempool_create(number, mempool_alloc_slab,
1400                                                 mempool_free_slab,
1401                                                 memp->request_pool);
1402
1403         if (!memp->request_mempool)
1404                 goto err1;
1405
1406         sdevice->hostdata = memp;
1407
1408         return 0;
1409
1410 err1:
1411         kmem_cache_destroy(memp->request_pool);
1412
1413 err0:
1414         kfree(memp);
1415         return -ENOMEM;
1416 }
1417
1418 static void storvsc_device_destroy(struct scsi_device *sdevice)
1419 {
1420         struct stor_mem_pools *memp = sdevice->hostdata;
1421
1422         mempool_destroy(memp->request_mempool);
1423         kmem_cache_destroy(memp->request_pool);
1424         kfree(memp);
1425         sdevice->hostdata = NULL;
1426 }
1427
1428 static int storvsc_device_configure(struct scsi_device *sdevice)
1429 {
1430         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
1431                                 STORVSC_MAX_IO_REQUESTS);
1432
1433         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1434
1435         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1436
1437         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1438
1439         sdevice->no_write_same = 1;
1440
1441         return 0;
1442 }
1443
1444 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1445                            sector_t capacity, int *info)
1446 {
1447         sector_t nsect = capacity;
1448         sector_t cylinders = nsect;
1449         int heads, sectors_pt;
1450
1451         /*
1452          * We are making up these values; let us keep it simple.
1453          */
1454         heads = 0xff;
1455         sectors_pt = 0x3f;      /* Sectors per track */
1456         sector_div(cylinders, heads * sectors_pt);
1457         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1458                 cylinders = 0xffff;
1459
1460         info[0] = heads;
1461         info[1] = sectors_pt;
1462         info[2] = (int)cylinders;
1463
1464         return 0;
1465 }
1466
1467 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1468 {
1469         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1470         struct hv_device *device = host_dev->dev;
1471
1472         struct storvsc_device *stor_device;
1473         struct storvsc_cmd_request *request;
1474         struct vstor_packet *vstor_packet;
1475         int ret, t;
1476
1477
1478         stor_device = get_out_stor_device(device);
1479         if (!stor_device)
1480                 return FAILED;
1481
1482         request = &stor_device->reset_request;
1483         vstor_packet = &request->vstor_packet;
1484
1485         init_completion(&request->wait_event);
1486
1487         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1488         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1489         vstor_packet->vm_srb.path_id = stor_device->path_id;
1490
1491         ret = vmbus_sendpacket(device->channel, vstor_packet,
1492                                (sizeof(struct vstor_packet) -
1493                                 vmscsi_size_delta),
1494                                (unsigned long)&stor_device->reset_request,
1495                                VM_PKT_DATA_INBAND,
1496                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1497         if (ret != 0)
1498                 return FAILED;
1499
1500         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1501         if (t == 0)
1502                 return TIMEOUT_ERROR;
1503
1504
1505         /*
1506          * At this point, all outstanding requests in the adapter
1507          * should have been flushed out and return to us
1508          * There is a potential race here where the host may be in
1509          * the process of responding when we return from here.
1510          * Just wait for all in-transit packets to be accounted for
1511          * before we return from here.
1512          */
1513         storvsc_wait_to_drain(stor_device);
1514
1515         return SUCCESS;
1516 }
1517
1518 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1519 {
1520         bool allowed = true;
1521         u8 scsi_op = scmnd->cmnd[0];
1522
1523         switch (scsi_op) {
1524         /* the host does not handle WRITE_SAME, log accident usage */
1525         case WRITE_SAME:
1526         /*
1527          * smartd sends this command and the host does not handle
1528          * this. So, don't send it.
1529          */
1530         case SET_WINDOW:
1531                 scmnd->result = ILLEGAL_REQUEST << 16;
1532                 allowed = false;
1533                 break;
1534         default:
1535                 break;
1536         }
1537         return allowed;
1538 }
1539
1540 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1541 {
1542         int ret;
1543         struct hv_host_device *host_dev = shost_priv(host);
1544         struct hv_device *dev = host_dev->dev;
1545         struct storvsc_cmd_request *cmd_request;
1546         unsigned int request_size = 0;
1547         int i;
1548         struct scatterlist *sgl;
1549         unsigned int sg_count = 0;
1550         struct vmscsi_request *vm_srb;
1551         struct stor_mem_pools *memp = scmnd->device->hostdata;
1552
1553         if (!storvsc_scsi_cmd_ok(scmnd)) {
1554                 scmnd->scsi_done(scmnd);
1555                 return 0;
1556         }
1557
1558         request_size = sizeof(struct storvsc_cmd_request);
1559
1560         cmd_request = mempool_alloc(memp->request_mempool,
1561                                        GFP_ATOMIC);
1562
1563         /*
1564          * We might be invoked in an interrupt context; hence
1565          * mempool_alloc() can fail.
1566          */
1567         if (!cmd_request)
1568                 return SCSI_MLQUEUE_DEVICE_BUSY;
1569
1570         memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
1571
1572         /* Setup the cmd request */
1573         cmd_request->cmd = scmnd;
1574
1575         scmnd->host_scribble = (unsigned char *)cmd_request;
1576
1577         vm_srb = &cmd_request->vstor_packet.vm_srb;
1578         vm_srb->win8_extension.time_out_value = 60;
1579
1580
1581         /* Build the SRB */
1582         switch (scmnd->sc_data_direction) {
1583         case DMA_TO_DEVICE:
1584                 vm_srb->data_in = WRITE_TYPE;
1585                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1586                 vm_srb->win8_extension.srb_flags |=
1587                         (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1588                         SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1589                 break;
1590         case DMA_FROM_DEVICE:
1591                 vm_srb->data_in = READ_TYPE;
1592                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1593                 vm_srb->win8_extension.srb_flags |=
1594                         (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1595                         SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1596                 break;
1597         default:
1598                 vm_srb->data_in = UNKNOWN_TYPE;
1599                 vm_srb->win8_extension.srb_flags = 0;
1600                 break;
1601         }
1602
1603
1604         vm_srb->port_number = host_dev->port;
1605         vm_srb->path_id = scmnd->device->channel;
1606         vm_srb->target_id = scmnd->device->id;
1607         vm_srb->lun = scmnd->device->lun;
1608
1609         vm_srb->cdb_length = scmnd->cmd_len;
1610
1611         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1612
1613         cmd_request->sense_buffer = scmnd->sense_buffer;
1614
1615
1616         cmd_request->data_buffer.len = scsi_bufflen(scmnd);
1617         if (scsi_sg_count(scmnd)) {
1618                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1619                 sg_count = scsi_sg_count(scmnd);
1620
1621                 /* check if we need to bounce the sgl */
1622                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1623                         cmd_request->bounce_sgl =
1624                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1625                                                      scsi_bufflen(scmnd),
1626                                                      vm_srb->data_in);
1627                         if (!cmd_request->bounce_sgl) {
1628                                 ret = SCSI_MLQUEUE_HOST_BUSY;
1629                                 goto queue_error;
1630                         }
1631
1632                         cmd_request->bounce_sgl_count =
1633                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1634                                         PAGE_SHIFT;
1635
1636                         if (vm_srb->data_in == WRITE_TYPE)
1637                                 copy_to_bounce_buffer(sgl,
1638                                         cmd_request->bounce_sgl,
1639                                         scsi_sg_count(scmnd));
1640
1641                         sgl = cmd_request->bounce_sgl;
1642                         sg_count = cmd_request->bounce_sgl_count;
1643                 }
1644
1645                 cmd_request->data_buffer.offset = sgl[0].offset;
1646
1647                 for (i = 0; i < sg_count; i++)
1648                         cmd_request->data_buffer.pfn_array[i] =
1649                                 page_to_pfn(sg_page((&sgl[i])));
1650
1651         } else if (scsi_sglist(scmnd)) {
1652                 cmd_request->data_buffer.offset =
1653                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1654                 cmd_request->data_buffer.pfn_array[0] =
1655                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1656         }
1657
1658         /* Invokes the vsc to start an IO */
1659         ret = storvsc_do_io(dev, cmd_request);
1660
1661         if (ret == -EAGAIN) {
1662                 /* no more space */
1663
1664                 if (cmd_request->bounce_sgl_count) {
1665                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1666                                         cmd_request->bounce_sgl_count);
1667
1668                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1669                         goto queue_error;
1670                 }
1671         }
1672
1673         return 0;
1674
1675 queue_error:
1676         mempool_free(cmd_request, memp->request_mempool);
1677         scmnd->host_scribble = NULL;
1678         return ret;
1679 }
1680
1681 static struct scsi_host_template scsi_driver = {
1682         .module =               THIS_MODULE,
1683         .name =                 "storvsc_host_t",
1684         .bios_param =           storvsc_get_chs,
1685         .queuecommand =         storvsc_queuecommand,
1686         .eh_host_reset_handler =        storvsc_host_reset_handler,
1687         .slave_alloc =          storvsc_device_alloc,
1688         .slave_destroy =        storvsc_device_destroy,
1689         .slave_configure =      storvsc_device_configure,
1690         .cmd_per_lun =          1,
1691         /* 64 max_queue * 1 target */
1692         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1693         .this_id =              -1,
1694         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1695         /* currently 32 */
1696         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1697         .use_clustering =       DISABLE_CLUSTERING,
1698         /* Make sure we dont get a sg segment crosses a page boundary */
1699         .dma_boundary =         PAGE_SIZE-1,
1700 };
1701
1702 enum {
1703         SCSI_GUID,
1704         IDE_GUID,
1705         SFC_GUID,
1706 };
1707
1708 static const struct hv_vmbus_device_id id_table[] = {
1709         /* SCSI guid */
1710         { HV_SCSI_GUID,
1711           .driver_data = SCSI_GUID
1712         },
1713         /* IDE guid */
1714         { HV_IDE_GUID,
1715           .driver_data = IDE_GUID
1716         },
1717         /* Fibre Channel GUID */
1718         {
1719           HV_SYNTHFC_GUID,
1720           .driver_data = SFC_GUID
1721         },
1722         { },
1723 };
1724
1725 MODULE_DEVICE_TABLE(vmbus, id_table);
1726
1727 static int storvsc_probe(struct hv_device *device,
1728                         const struct hv_vmbus_device_id *dev_id)
1729 {
1730         int ret;
1731         struct Scsi_Host *host;
1732         struct hv_host_device *host_dev;
1733         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1734         int target = 0;
1735         struct storvsc_device *stor_device;
1736
1737         /*
1738          * Based on the windows host we are running on,
1739          * set state to properly communicate with the host.
1740          */
1741
1742         if (vmbus_proto_version == VERSION_WIN8) {
1743                 sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
1744                 vmscsi_size_delta = 0;
1745                 vmstor_current_major = VMSTOR_WIN8_MAJOR;
1746                 vmstor_current_minor = VMSTOR_WIN8_MINOR;
1747         } else {
1748                 sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
1749                 vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1750                 vmstor_current_major = VMSTOR_WIN7_MAJOR;
1751                 vmstor_current_minor = VMSTOR_WIN7_MINOR;
1752         }
1753
1754
1755         host = scsi_host_alloc(&scsi_driver,
1756                                sizeof(struct hv_host_device));
1757         if (!host)
1758                 return -ENOMEM;
1759
1760         host_dev = shost_priv(host);
1761         memset(host_dev, 0, sizeof(struct hv_host_device));
1762
1763         host_dev->port = host->host_no;
1764         host_dev->dev = device;
1765
1766
1767         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1768         if (!stor_device) {
1769                 ret = -ENOMEM;
1770                 goto err_out0;
1771         }
1772
1773         stor_device->destroy = false;
1774         stor_device->open_sub_channel = false;
1775         init_waitqueue_head(&stor_device->waiting_to_drain);
1776         stor_device->device = device;
1777         stor_device->host = host;
1778         hv_set_drvdata(device, stor_device);
1779
1780         stor_device->port_number = host->host_no;
1781         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1782         if (ret)
1783                 goto err_out1;
1784
1785         host_dev->path = stor_device->path_id;
1786         host_dev->target = stor_device->target_id;
1787
1788         /* max # of devices per target */
1789         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1790         /* max # of targets per channel */
1791         host->max_id = STORVSC_MAX_TARGETS;
1792         /* max # of channels */
1793         host->max_channel = STORVSC_MAX_CHANNELS - 1;
1794         /* max cmd length */
1795         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1796
1797         /* Register the HBA and start the scsi bus scan */
1798         ret = scsi_add_host(host, &device->device);
1799         if (ret != 0)
1800                 goto err_out2;
1801
1802         if (!dev_is_ide) {
1803                 scsi_scan_host(host);
1804         } else {
1805                 target = (device->dev_instance.b[5] << 8 |
1806                          device->dev_instance.b[4]);
1807                 ret = scsi_add_device(host, 0, target, 0);
1808                 if (ret) {
1809                         scsi_remove_host(host);
1810                         goto err_out2;
1811                 }
1812         }
1813         return 0;
1814
1815 err_out2:
1816         /*
1817          * Once we have connected with the host, we would need to
1818          * to invoke storvsc_dev_remove() to rollback this state and
1819          * this call also frees up the stor_device; hence the jump around
1820          * err_out1 label.
1821          */
1822         storvsc_dev_remove(device);
1823         goto err_out0;
1824
1825 err_out1:
1826         kfree(stor_device);
1827
1828 err_out0:
1829         scsi_host_put(host);
1830         return ret;
1831 }
1832
1833 static int storvsc_remove(struct hv_device *dev)
1834 {
1835         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1836         struct Scsi_Host *host = stor_device->host;
1837
1838         scsi_remove_host(host);
1839         storvsc_dev_remove(dev);
1840         scsi_host_put(host);
1841
1842         return 0;
1843 }
1844
1845 static struct hv_driver storvsc_drv = {
1846         .name = KBUILD_MODNAME,
1847         .id_table = id_table,
1848         .probe = storvsc_probe,
1849         .remove = storvsc_remove,
1850 };
1851
1852 static int __init storvsc_drv_init(void)
1853 {
1854         u32 max_outstanding_req_per_channel;
1855
1856         /*
1857          * Divide the ring buffer data size (which is 1 page less
1858          * than the ring buffer size since that page is reserved for
1859          * the ring buffer indices) by the max request size (which is
1860          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1861          */
1862         max_outstanding_req_per_channel =
1863                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1864                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1865                 sizeof(struct vstor_packet) + sizeof(u64) -
1866                 vmscsi_size_delta,
1867                 sizeof(u64)));
1868
1869         if (max_outstanding_req_per_channel <
1870             STORVSC_MAX_IO_REQUESTS)
1871                 return -EINVAL;
1872
1873         return vmbus_driver_register(&storvsc_drv);
1874 }
1875
1876 static void __exit storvsc_drv_exit(void)
1877 {
1878         vmbus_driver_unregister(&storvsc_drv);
1879 }
1880
1881 MODULE_LICENSE("GPL");
1882 MODULE_VERSION(HV_DRV_VERSION);
1883 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1884 module_init(storvsc_drv_init);
1885 module_exit(storvsc_drv_exit);