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 <linux/blkdev.h>
  37 #include <scsi/scsi.h>
  38 #include <scsi/scsi_cmnd.h>
  39 #include <scsi/scsi_host.h>
  40 #include <scsi/scsi_device.h>
  41 #include <scsi/scsi_tcq.h>
  42 #include <scsi/scsi_eh.h>
  43 #include <scsi/scsi_devinfo.h>
  44 #include <scsi/scsi_dbg.h>
  45
  46 /*
  47  * All wire protocol details (storage protocol between the guest and the host)
  48  * are consolidated here.
  49  *
  50  * Begin protocol definitions.
  51  */
  52
  53 /*
  54  * Version history:
  55  * V1 Beta: 0.1
  56  * V1 RC < 2008/1/31: 1.0
  57  * V1 RC > 2008/1/31:  2.0
  58  * Win7: 4.2
  59  * Win8: 5.1
  60  */
  61
  62
  63 #define VMSTOR_WIN7_MAJOR 4
  64 #define VMSTOR_WIN7_MINOR 2
  65
  66 #define VMSTOR_WIN8_MAJOR 5
  67 #define VMSTOR_WIN8_MINOR 1
  68
  69
  70 /*  Packet structure describing virtual storage requests. */
  71 enum vstor_packet_operation {
  72         VSTOR_OPERATION_COMPLETE_IO             = 1,
  73         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  74         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  75         VSTOR_OPERATION_RESET_LUN               = 4,
  76         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  77         VSTOR_OPERATION_RESET_BUS               = 6,
  78         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  79         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  80         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  81         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  82         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  83         VSTOR_OPERATION_FCHBA_DATA              = 12,
  84         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  85         VSTOR_OPERATION_MAXIMUM                 = 13
  86 };
  87
  88 /*
  89  * WWN packet for Fibre Channel HBA
  90  */
  91
  92 struct hv_fc_wwn_packet {
  93         bool    primary_active;
  94         u8      reserved1;
  95         u8      reserved2;
  96         u8      primary_port_wwn[8];
  97         u8      primary_node_wwn[8];
  98         u8      secondary_port_wwn[8];
  99         u8      secondary_node_wwn[8];
 100 };
 101
 102
 103
 104 /*
 105  * SRB Flag Bits
 106  */
 107
 108 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 109 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 110 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 111 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 112 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 113 #define SRB_FLAGS_DATA_IN                       0x00000040
 114 #define SRB_FLAGS_DATA_OUT                      0x00000080
 115 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 116 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 117 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 118 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 119 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 120
 121 /*
 122  * This flag indicates the request is part of the workflow for processing a D3.
 123  */
 124 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 125 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 126 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 127 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 128 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 129 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 130 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 131 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 132 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 133 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 134 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 135
 136
 137 /*
 138  * Platform neutral description of a scsi request -
 139  * this remains the same across the write regardless of 32/64 bit
 140  * note: it's patterned off the SCSI_PASS_THROUGH structure
 141  */
 142 #define STORVSC_MAX_CMD_LEN                     0x10
 143
 144 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 145 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 146
 147 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 148 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 149
 150 /*
 151  * Sense buffer size changed in win8; have a run-time
 152  * variable to track the size we should use.
 153  */
 154 static int sense_buffer_size;
 155
 156 /*
 157  * The size of the vmscsi_request has changed in win8. The
 158  * additional size is because of new elements added to the
 159  * structure. These elements are valid only when we are talking
 160  * to a win8 host.
 161  * Track the correction to size we need to apply.
 162  */
 163
 164 static int vmscsi_size_delta;
 165 static int vmstor_current_major;
 166 static int vmstor_current_minor;
 167
 168 struct vmscsi_win8_extension {
 169         /*
 170          * The following were added in Windows 8
 171          */
 172         u16 reserve;
 173         u8  queue_tag;
 174         u8  queue_action;
 175         u32 srb_flags;
 176         u32 time_out_value;
 177         u32 queue_sort_ey;
 178 } __packed;
 179
 180 struct vmscsi_request {
 181         u16 length;
 182         u8 srb_status;
 183         u8 scsi_status;
 184
 185         u8  port_number;
 186         u8  path_id;
 187         u8  target_id;
 188         u8  lun;
 189
 190         u8  cdb_length;
 191         u8  sense_info_length;
 192         u8  data_in;
 193         u8  reserved;
 194
 195         u32 data_transfer_length;
 196
 197         union {
 198                 u8 cdb[STORVSC_MAX_CMD_LEN];
 199                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 200                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 201         };
 202         /*
 203          * The following was added in win8.
 204          */
 205         struct vmscsi_win8_extension win8_extension;
 206
 207 } __attribute((packed));
 208
 209
 210 /*
 211  * This structure is sent during the intialization phase to get the different
 212  * properties of the channel.
 213  */
 214
 215 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 216
 217 struct vmstorage_channel_properties {
 218         u32 reserved;
 219         u16 max_channel_cnt;
 220         u16 reserved1;
 221
 222         u32 flags;
 223         u32   max_transfer_bytes;
 224
 225         u64  reserved2;
 226 } __packed;
 227
 228 /*  This structure is sent during the storage protocol negotiations. */
 229 struct vmstorage_protocol_version {
 230         /* Major (MSW) and minor (LSW) version numbers. */
 231         u16 major_minor;
 232
 233         /*
 234          * Revision number is auto-incremented whenever this file is changed
 235          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 236          * definitely indicate incompatibility--but it does indicate mismatched
 237          * builds.
 238          * This is only used on the windows side. Just set it to 0.
 239          */
 240         u16 revision;
 241 } __packed;
 242
 243 /* Channel Property Flags */
 244 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 245 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 246
 247 struct vstor_packet {
 248         /* Requested operation type */
 249         enum vstor_packet_operation operation;
 250
 251         /*  Flags - see below for values */
 252         u32 flags;
 253
 254         /* Status of the request returned from the server side. */
 255         u32 status;
 256
 257         /* Data payload area */
 258         union {
 259                 /*
 260                  * Structure used to forward SCSI commands from the
 261                  * client to the server.
 262                  */
 263                 struct vmscsi_request vm_srb;
 264
 265                 /* Structure used to query channel properties. */
 266                 struct vmstorage_channel_properties storage_channel_properties;
 267
 268                 /* Used during version negotiations. */
 269                 struct vmstorage_protocol_version version;
 270
 271                 /* Fibre channel address packet */
 272                 struct hv_fc_wwn_packet wwn_packet;
 273
 274                 /* Number of sub-channels to create */
 275                 u16 sub_channel_count;
 276
 277                 /* This will be the maximum of the union members */
 278                 u8  buffer[0x34];
 279         };
 280 } __packed;
 281
 282 /*
 283  * Packet Flags:
 284  *
 285  * This flag indicates that the server should send back a completion for this
 286  * packet.
 287  */
 288
 289 #define REQUEST_COMPLETION_FLAG 0x1
 290
 291 /* Matches Windows-end */
 292 enum storvsc_request_type {
 293         WRITE_TYPE = 0,
 294         READ_TYPE,
 295         UNKNOWN_TYPE,
 296 };
 297
 298 /*
 299  * SRB status codes and masks; a subset of the codes used here.
 300  */
 301
 302 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 303 #define SRB_STATUS_INVALID_LUN  0x20
 304 #define SRB_STATUS_SUCCESS      0x01
 305 #define SRB_STATUS_ABORTED      0x02
 306 #define SRB_STATUS_ERROR        0x04
 307
 308 /*
 309  * This is the end of Protocol specific defines.
 310  */
 311
 312
 313 /*
 314  * We setup a mempool to allocate request structures for this driver
 315  * on a per-lun basis. The following define specifies the number of
 316  * elements in the pool.
 317  */
 318
 319 #define STORVSC_MIN_BUF_NR                              64
 320 static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
 321
 322 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 323 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 324
 325 /*
 326  * Timeout in seconds for all devices managed by this driver.
 327  */
 328 static int storvsc_timeout = 180;
 329
 330 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
 331
 332 #define STORVSC_MAX_IO_REQUESTS                         200
 333
 334 static void storvsc_on_channel_callback(void *context);
 335
 336 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 337 #define STORVSC_MAX_TARGETS                             2
 338 #define STORVSC_MAX_CHANNELS                            8
 339
 340 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 341 #define STORVSC_FC_MAX_TARGETS                          128
 342 #define STORVSC_FC_MAX_CHANNELS                         8
 343
 344 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 345 #define STORVSC_IDE_MAX_TARGETS                         1
 346 #define STORVSC_IDE_MAX_CHANNELS                        1
 347
 348 struct storvsc_cmd_request {
 349         struct list_head entry;
 350         struct scsi_cmnd *cmd;
 351
 352         unsigned int bounce_sgl_count;
 353         struct scatterlist *bounce_sgl;
 354
 355         struct hv_device *device;
 356
 357         /* Synchronize the request/response if needed */
 358         struct completion wait_event;
 359
 360         unsigned char *sense_buffer;
 361         struct hv_multipage_buffer data_buffer;
 362         struct vstor_packet vstor_packet;
 363 };
 364
 365
 366 /* A storvsc device is a device object that contains a vmbus channel */
 367 struct storvsc_device {
 368         struct hv_device *device;
 369
 370         bool     destroy;
 371         bool     drain_notify;
 372         bool     open_sub_channel;
 373         atomic_t num_outstanding_req;
 374         struct Scsi_Host *host;
 375
 376         wait_queue_head_t waiting_to_drain;
 377
 378         /*
 379          * Each unique Port/Path/Target represents 1 channel ie scsi
 380          * controller. In reality, the pathid, targetid is always 0
 381          * and the port is set by us
 382          */
 383         unsigned int port_number;
 384         unsigned char path_id;
 385         unsigned char target_id;
 386
 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 stor_mem_pools {
 393         struct kmem_cache *request_pool;
 394         mempool_t *request_mempool;
 395 };
 396
 397 struct hv_host_device {
 398         struct hv_device *dev;
 399         unsigned int port;
 400         unsigned char path;
 401         unsigned char target;
 402 };
 403
 404 struct storvsc_scan_work {
 405         struct work_struct work;
 406         struct Scsi_Host *host;
 407         uint lun;
 408 };
 409
 410 static void storvsc_device_scan(struct work_struct *work)
 411 {
 412         struct storvsc_scan_work *wrk;
 413         uint lun;
 414         struct scsi_device *sdev;
 415
 416         wrk = container_of(work, struct storvsc_scan_work, work);
 417         lun = wrk->lun;
 418
 419         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 420         if (!sdev)
 421                 goto done;
 422         scsi_rescan_device(&sdev->sdev_gendev);
 423         scsi_device_put(sdev);
 424
 425 done:
 426         kfree(wrk);
 427 }
 428
 429 static void storvsc_bus_scan(struct work_struct *work)
 430 {
 431         struct storvsc_scan_work *wrk;
 432         int id, order_id;
 433
 434         wrk = container_of(work, struct storvsc_scan_work, work);
 435         for (id = 0; id < wrk->host->max_id; ++id) {
 436                 if (wrk->host->reverse_ordering)
 437                         order_id = wrk->host->max_id - id - 1;
 438                 else
 439                         order_id = id;
 440
 441                 scsi_scan_target(&wrk->host->shost_gendev, 0,
 442                                 order_id, SCAN_WILD_CARD, 1);
 443         }
 444         kfree(wrk);
 445 }
 446
 447 static void storvsc_remove_lun(struct work_struct *work)
 448 {
 449         struct storvsc_scan_work *wrk;
 450         struct scsi_device *sdev;
 451
 452         wrk = container_of(work, struct storvsc_scan_work, work);
 453         if (!scsi_host_get(wrk->host))
 454                 goto done;
 455
 456         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 457
 458         if (sdev) {
 459                 scsi_remove_device(sdev);
 460                 scsi_device_put(sdev);
 461         }
 462         scsi_host_put(wrk->host);
 463
 464 done:
 465         kfree(wrk);
 466 }
 467
 468 /*
 469  * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 470  * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 471  */
 472
 473 static inline u16 storvsc_get_version(u8 major, u8 minor)
 474 {
 475         u16 version;
 476
 477         version = ((major << 8) | minor);
 478         return version;
 479 }
 480
 481 /*
 482  * We can get incoming messages from the host that are not in response to
 483  * messages that we have sent out. An example of this would be messages
 484  * received by the guest to notify dynamic addition/removal of LUNs. To
 485  * deal with potential race conditions where the driver may be in the
 486  * midst of being unloaded when we might receive an unsolicited message
 487  * from the host, we have implemented a mechanism to gurantee sequential
 488  * consistency:
 489  *
 490  * 1) Once the device is marked as being destroyed, we will fail all
 491  *    outgoing messages.
 492  * 2) We permit incoming messages when the device is being destroyed,
 493  *    only to properly account for messages already sent out.
 494  */
 495
 496 static inline struct storvsc_device *get_out_stor_device(
 497                                         struct hv_device *device)
 498 {
 499         struct storvsc_device *stor_device;
 500
 501         stor_device = hv_get_drvdata(device);
 502
 503         if (stor_device && stor_device->destroy)
 504                 stor_device = NULL;
 505
 506         return stor_device;
 507 }
 508
 509
 510 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 511 {
 512         dev->drain_notify = true;
 513         wait_event(dev->waiting_to_drain,
 514                    atomic_read(&dev->num_outstanding_req) == 0);
 515         dev->drain_notify = false;
 516 }
 517
 518 static inline struct storvsc_device *get_in_stor_device(
 519                                         struct hv_device *device)
 520 {
 521         struct storvsc_device *stor_device;
 522
 523         stor_device = hv_get_drvdata(device);
 524
 525         if (!stor_device)
 526                 goto get_in_err;
 527
 528         /*
 529          * If the device is being destroyed; allow incoming
 530          * traffic only to cleanup outstanding requests.
 531          */
 532
 533         if (stor_device->destroy  &&
 534                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 535                 stor_device = NULL;
 536
 537 get_in_err:
 538         return stor_device;
 539
 540 }
 541
 542 static void destroy_bounce_buffer(struct scatterlist *sgl,
 543                                   unsigned int sg_count)
 544 {
 545         int i;
 546         struct page *page_buf;
 547
 548         for (i = 0; i < sg_count; i++) {
 549                 page_buf = sg_page((&sgl[i]));
 550                 if (page_buf != NULL)
 551                         __free_page(page_buf);
 552         }
 553
 554         kfree(sgl);
 555 }
 556
 557 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 558 {
 559         int i;
 560
 561         /* No need to check */
 562         if (sg_count < 2)
 563                 return -1;
 564
 565         /* We have at least 2 sg entries */
 566         for (i = 0; i < sg_count; i++) {
 567                 if (i == 0) {
 568                         /* make sure 1st one does not have hole */
 569                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 570                                 return i;
 571                 } else if (i == sg_count - 1) {
 572                         /* make sure last one does not have hole */
 573                         if (sgl[i].offset != 0)
 574                                 return i;
 575                 } else {
 576                         /* make sure no hole in the middle */
 577                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 578                                 return i;
 579                 }
 580         }
 581         return -1;
 582 }
 583
 584 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 585                                                 unsigned int sg_count,
 586                                                 unsigned int len,
 587                                                 int write)
 588 {
 589         int i;
 590         int num_pages;
 591         struct scatterlist *bounce_sgl;
 592         struct page *page_buf;
 593         unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 594
 595         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 596
 597         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 598         if (!bounce_sgl)
 599                 return NULL;
 600
 601         sg_init_table(bounce_sgl, num_pages);
 602         for (i = 0; i < num_pages; i++) {
 603                 page_buf = alloc_page(GFP_ATOMIC);
 604                 if (!page_buf)
 605                         goto cleanup;
 606                 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 607         }
 608
 609         return bounce_sgl;
 610
 611 cleanup:
 612         destroy_bounce_buffer(bounce_sgl, num_pages);
 613         return NULL;
 614 }
 615
 616 /* Disgusting wrapper functions */
 617 static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
 618 {
 619         void *addr = kmap_atomic(sg_page(sgl + idx));
 620         return (unsigned long)addr;
 621 }
 622
 623 static inline void sg_kunmap_atomic(unsigned long addr)
 624 {
 625         kunmap_atomic((void *)addr);
 626 }
 627
 628
 629 /* Assume the original sgl has enough room */
 630 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 631                                             struct scatterlist *bounce_sgl,
 632                                             unsigned int orig_sgl_count,
 633                                             unsigned int bounce_sgl_count)
 634 {
 635         int i;
 636         int j = 0;
 637         unsigned long src, dest;
 638         unsigned int srclen, destlen, copylen;
 639         unsigned int total_copied = 0;
 640         unsigned long bounce_addr = 0;
 641         unsigned long dest_addr = 0;
 642         unsigned long flags;
 643
 644         local_irq_save(flags);
 645
 646         for (i = 0; i < orig_sgl_count; i++) {
 647                 dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 648                 dest = dest_addr;
 649                 destlen = orig_sgl[i].length;
 650
 651                 if (bounce_addr == 0)
 652                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 653
 654                 while (destlen) {
 655                         src = bounce_addr + bounce_sgl[j].offset;
 656                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 657
 658                         copylen = min(srclen, destlen);
 659                         memcpy((void *)dest, (void *)src, copylen);
 660
 661                         total_copied += copylen;
 662                         bounce_sgl[j].offset += copylen;
 663                         destlen -= copylen;
 664                         dest += copylen;
 665
 666                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 667                                 /* full */
 668                                 sg_kunmap_atomic(bounce_addr);
 669                                 j++;
 670
 671                                 /*
 672                                  * It is possible that the number of elements
 673                                  * in the bounce buffer may not be equal to
 674                                  * the number of elements in the original
 675                                  * scatter list. Handle this correctly.
 676                                  */
 677
 678                                 if (j == bounce_sgl_count) {
 679                                         /*
 680                                          * We are done; cleanup and return.
 681                                          */
 682                                         sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 683                                         local_irq_restore(flags);
 684                                         return total_copied;
 685                                 }
 686
 687                                 /* if we need to use another bounce buffer */
 688                                 if (destlen || i != orig_sgl_count - 1)
 689                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 690                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 691                                 /* unmap the last bounce that is < PAGE_SIZE */
 692                                 sg_kunmap_atomic(bounce_addr);
 693                         }
 694                 }
 695
 696                 sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 697         }
 698
 699         local_irq_restore(flags);
 700
 701         return total_copied;
 702 }
 703
 704 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 705 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 706                                           struct scatterlist *bounce_sgl,
 707                                           unsigned int orig_sgl_count)
 708 {
 709         int i;
 710         int j = 0;
 711         unsigned long src, dest;
 712         unsigned int srclen, destlen, copylen;
 713         unsigned int total_copied = 0;
 714         unsigned long bounce_addr = 0;
 715         unsigned long src_addr = 0;
 716         unsigned long flags;
 717
 718         local_irq_save(flags);
 719
 720         for (i = 0; i < orig_sgl_count; i++) {
 721                 src_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 722                 src = src_addr;
 723                 srclen = orig_sgl[i].length;
 724
 725                 if (bounce_addr == 0)
 726                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 727
 728                 while (srclen) {
 729                         /* assume bounce offset always == 0 */
 730                         dest = bounce_addr + bounce_sgl[j].length;
 731                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 732
 733                         copylen = min(srclen, destlen);
 734                         memcpy((void *)dest, (void *)src, copylen);
 735
 736                         total_copied += copylen;
 737                         bounce_sgl[j].length += copylen;
 738                         srclen -= copylen;
 739                         src += copylen;
 740
 741                         if (bounce_sgl[j].length == PAGE_SIZE) {
 742                                 /* full..move to next entry */
 743                                 sg_kunmap_atomic(bounce_addr);
 744                                 j++;
 745
 746                                 /* if we need to use another bounce buffer */
 747                                 if (srclen || i != orig_sgl_count - 1)
 748                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 749
 750                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 751                                 /* unmap the last bounce that is < PAGE_SIZE */
 752                                 sg_kunmap_atomic(bounce_addr);
 753                         }
 754                 }
 755
 756                 sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
 757         }
 758
 759         local_irq_restore(flags);
 760
 761         return total_copied;
 762 }
 763
 764 static void handle_sc_creation(struct vmbus_channel *new_sc)
 765 {
 766         struct hv_device *device = new_sc->primary_channel->device_obj;
 767         struct storvsc_device *stor_device;
 768         struct vmstorage_channel_properties props;
 769
 770         stor_device = get_out_stor_device(device);
 771         if (!stor_device)
 772                 return;
 773
 774         if (stor_device->open_sub_channel == false)
 775                 return;
 776
 777         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 778
 779         vmbus_open(new_sc,
 780                    storvsc_ringbuffer_size,
 781                    storvsc_ringbuffer_size,
 782                    (void *)&props,
 783                    sizeof(struct vmstorage_channel_properties),
 784                    storvsc_on_channel_callback, new_sc);
 785 }
 786
 787 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 788 {
 789         struct storvsc_device *stor_device;
 790         int num_cpus = num_online_cpus();
 791         int num_sc;
 792         struct storvsc_cmd_request *request;
 793         struct vstor_packet *vstor_packet;
 794         int ret, t;
 795
 796         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 797         stor_device = get_out_stor_device(device);
 798         if (!stor_device)
 799                 return;
 800
 801         request = &stor_device->init_request;
 802         vstor_packet = &request->vstor_packet;
 803
 804         stor_device->open_sub_channel = true;
 805         /*
 806          * Establish a handler for dealing with subchannels.
 807          */
 808         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 809
 810         /*
 811          * Check to see if sub-channels have already been created. This
 812          * can happen when this driver is re-loaded after unloading.
 813          */
 814
 815         if (vmbus_are_subchannels_present(device->channel))
 816                 return;
 817
 818         stor_device->open_sub_channel = false;
 819         /*
 820          * Request the host to create sub-channels.
 821          */
 822         memset(request, 0, sizeof(struct storvsc_cmd_request));
 823         init_completion(&request->wait_event);
 824         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 825         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 826         vstor_packet->sub_channel_count = num_sc;
 827
 828         ret = vmbus_sendpacket(device->channel, vstor_packet,
 829                                (sizeof(struct vstor_packet) -
 830                                vmscsi_size_delta),
 831                                (unsigned long)request,
 832                                VM_PKT_DATA_INBAND,
 833                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 834
 835         if (ret != 0)
 836                 return;
 837
 838         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 839         if (t == 0)
 840                 return;
 841
 842         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 843             vstor_packet->status != 0)
 844                 return;
 845
 846         /*
 847          * Now that we created the sub-channels, invoke the check; this
 848          * may trigger the callback.
 849          */
 850         stor_device->open_sub_channel = true;
 851         vmbus_are_subchannels_present(device->channel);
 852 }
 853
 854 static int storvsc_channel_init(struct hv_device *device)
 855 {
 856         struct storvsc_device *stor_device;
 857         struct storvsc_cmd_request *request;
 858         struct vstor_packet *vstor_packet;
 859         int ret, t;
 860         int max_chns;
 861         bool process_sub_channels = false;
 862
 863         stor_device = get_out_stor_device(device);
 864         if (!stor_device)
 865                 return -ENODEV;
 866
 867         request = &stor_device->init_request;
 868         vstor_packet = &request->vstor_packet;
 869
 870         /*
 871          * Now, initiate the vsc/vsp initialization protocol on the open
 872          * channel
 873          */
 874         memset(request, 0, sizeof(struct storvsc_cmd_request));
 875         init_completion(&request->wait_event);
 876         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 877         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 878
 879         ret = vmbus_sendpacket(device->channel, vstor_packet,
 880                                (sizeof(struct vstor_packet) -
 881                                vmscsi_size_delta),
 882                                (unsigned long)request,
 883                                VM_PKT_DATA_INBAND,
 884                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 885         if (ret != 0)
 886                 goto cleanup;
 887
 888         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 889         if (t == 0) {
 890                 ret = -ETIMEDOUT;
 891                 goto cleanup;
 892         }
 893
 894         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 895             vstor_packet->status != 0)
 896                 goto cleanup;
 897
 898
 899         /* reuse the packet for version range supported */
 900         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 901         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 902         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 903
 904         vstor_packet->version.major_minor =
 905                 storvsc_get_version(vmstor_current_major, vmstor_current_minor);
 906
 907         /*
 908          * The revision number is only used in Windows; set it to 0.
 909          */
 910         vstor_packet->version.revision = 0;
 911
 912         ret = vmbus_sendpacket(device->channel, vstor_packet,
 913                                (sizeof(struct vstor_packet) -
 914                                 vmscsi_size_delta),
 915                                (unsigned long)request,
 916                                VM_PKT_DATA_INBAND,
 917                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 918         if (ret != 0)
 919                 goto cleanup;
 920
 921         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 922         if (t == 0) {
 923                 ret = -ETIMEDOUT;
 924                 goto cleanup;
 925         }
 926
 927         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 928             vstor_packet->status != 0)
 929                 goto cleanup;
 930
 931
 932         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 933         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 934         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 935
 936         ret = vmbus_sendpacket(device->channel, vstor_packet,
 937                                (sizeof(struct vstor_packet) -
 938                                 vmscsi_size_delta),
 939                                (unsigned long)request,
 940                                VM_PKT_DATA_INBAND,
 941                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 942
 943         if (ret != 0)
 944                 goto cleanup;
 945
 946         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 947         if (t == 0) {
 948                 ret = -ETIMEDOUT;
 949                 goto cleanup;
 950         }
 951
 952         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 953             vstor_packet->status != 0)
 954                 goto cleanup;
 955
 956         /*
 957          * Check to see if multi-channel support is there.
 958          * Hosts that implement protocol version of 5.1 and above
 959          * support multi-channel.
 960          */
 961         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 962         if ((vmbus_proto_version != VERSION_WIN7) &&
 963            (vmbus_proto_version != VERSION_WS2008))  {
 964                 if (vstor_packet->storage_channel_properties.flags &
 965                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 966                         process_sub_channels = true;
 967         }
 968
 969         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 970         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 971         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 972
 973         ret = vmbus_sendpacket(device->channel, vstor_packet,
 974                                (sizeof(struct vstor_packet) -
 975                                 vmscsi_size_delta),
 976                                (unsigned long)request,
 977                                VM_PKT_DATA_INBAND,
 978                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 979
 980         if (ret != 0)
 981                 goto cleanup;
 982
 983         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 984         if (t == 0) {
 985                 ret = -ETIMEDOUT;
 986                 goto cleanup;
 987         }
 988
 989         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 990             vstor_packet->status != 0)
 991                 goto cleanup;
 992
 993         if (process_sub_channels)
 994                 handle_multichannel_storage(device, max_chns);
 995
 996
 997 cleanup:
 998         return ret;
 999 }
1000
1001 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1002                                 struct scsi_cmnd *scmnd,
1003                                 struct Scsi_Host *host,
1004                                 u8 asc, u8 ascq)
1005 {
1006         struct storvsc_scan_work *wrk;
1007         void (*process_err_fn)(struct work_struct *work);
1008         bool do_work = false;
1009
1010         switch (vm_srb->srb_status) {
1011         case SRB_STATUS_ERROR:
1012                 /*
1013                  * If there is an error; offline the device since all
1014                  * error recovery strategies would have already been
1015                  * deployed on the host side. However, if the command
1016                  * were a pass-through command deal with it appropriately.
1017                  */
1018                 switch (scmnd->cmnd[0]) {
1019                 case ATA_16:
1020                 case ATA_12:
1021                         set_host_byte(scmnd, DID_PASSTHROUGH);
1022                         break;
1023                 /*
1024                  * On Some Windows hosts TEST_UNIT_READY command can return
1025                  * SRB_STATUS_ERROR, let the upper level code deal with it
1026                  * based on the sense information.
1027                  */
1028                 case TEST_UNIT_READY:
1029                         break;
1030                 default:
1031                         set_host_byte(scmnd, DID_TARGET_FAILURE);
1032                 }
1033                 break;
1034         case SRB_STATUS_INVALID_LUN:
1035                 do_work = true;
1036                 process_err_fn = storvsc_remove_lun;
1037                 break;
1038         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
1039                 if ((asc == 0x2a) && (ascq == 0x9)) {
1040                         do_work = true;
1041                         process_err_fn = storvsc_device_scan;
1042                         /*
1043                          * Retry the I/O that trigerred this.
1044                          */
1045                         set_host_byte(scmnd, DID_REQUEUE);
1046                 }
1047                 break;
1048         }
1049
1050         if (!do_work)
1051                 return;
1052
1053         /*
1054          * We need to schedule work to process this error; schedule it.
1055          */
1056         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1057         if (!wrk) {
1058                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1059                 return;
1060         }
1061
1062         wrk->host = host;
1063         wrk->lun = vm_srb->lun;
1064         INIT_WORK(&wrk->work, process_err_fn);
1065         schedule_work(&wrk->work);
1066 }
1067
1068
1069 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
1070 {
1071         struct scsi_cmnd *scmnd = cmd_request->cmd;
1072         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1073         void (*scsi_done_fn)(struct scsi_cmnd *);
1074         struct scsi_sense_hdr sense_hdr;
1075         struct vmscsi_request *vm_srb;
1076         struct stor_mem_pools *memp = scmnd->device->hostdata;
1077         struct Scsi_Host *host;
1078         struct storvsc_device *stor_dev;
1079         struct hv_device *dev = host_dev->dev;
1080
1081         stor_dev = get_in_stor_device(dev);
1082         host = stor_dev->host;
1083
1084         vm_srb = &cmd_request->vstor_packet.vm_srb;
1085         if (cmd_request->bounce_sgl_count) {
1086                 if (vm_srb->data_in == READ_TYPE)
1087                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1088                                         cmd_request->bounce_sgl,
1089                                         scsi_sg_count(scmnd),
1090                                         cmd_request->bounce_sgl_count);
1091                 destroy_bounce_buffer(cmd_request->bounce_sgl,
1092                                         cmd_request->bounce_sgl_count);
1093         }
1094
1095         scmnd->result = vm_srb->scsi_status;
1096
1097         if (scmnd->result) {
1098                 if (scsi_normalize_sense(scmnd->sense_buffer,
1099                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1100                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1101                                              &sense_hdr);
1102         }
1103
1104         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
1105                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1106                                          sense_hdr.ascq);
1107
1108         scsi_set_resid(scmnd,
1109                 cmd_request->data_buffer.len -
1110                 vm_srb->data_transfer_length);
1111
1112         scsi_done_fn = scmnd->scsi_done;
1113
1114         scmnd->host_scribble = NULL;
1115         scmnd->scsi_done = NULL;
1116
1117         scsi_done_fn(scmnd);
1118
1119         mempool_free(cmd_request, memp->request_mempool);
1120 }
1121
1122 static void storvsc_on_io_completion(struct hv_device *device,
1123                                   struct vstor_packet *vstor_packet,
1124                                   struct storvsc_cmd_request *request)
1125 {
1126         struct storvsc_device *stor_device;
1127         struct vstor_packet *stor_pkt;
1128
1129         stor_device = hv_get_drvdata(device);
1130         stor_pkt = &request->vstor_packet;
1131
1132         /*
1133          * The current SCSI handling on the host side does
1134          * not correctly handle:
1135          * INQUIRY command with page code parameter set to 0x80
1136          * MODE_SENSE command with cmd[2] == 0x1c
1137          *
1138          * Setup srb and scsi status so this won't be fatal.
1139          * We do this so we can distinguish truly fatal failues
1140          * (srb status == 0x4) and off-line the device in that case.
1141          */
1142
1143         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1144            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1145                 vstor_packet->vm_srb.scsi_status = 0;
1146                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1147         }
1148
1149
1150         /* Copy over the status...etc */
1151         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1152         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1153         stor_pkt->vm_srb.sense_info_length =
1154         vstor_packet->vm_srb.sense_info_length;
1155
1156
1157         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1158                 /* CHECK_CONDITION */
1159                 if (vstor_packet->vm_srb.srb_status &
1160                         SRB_STATUS_AUTOSENSE_VALID) {
1161                         /* autosense data available */
1162
1163                         memcpy(request->sense_buffer,
1164                                vstor_packet->vm_srb.sense_data,
1165                                vstor_packet->vm_srb.sense_info_length);
1166
1167                 }
1168         }
1169
1170         stor_pkt->vm_srb.data_transfer_length =
1171         vstor_packet->vm_srb.data_transfer_length;
1172
1173         storvsc_command_completion(request);
1174
1175         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1176                 stor_device->drain_notify)
1177                 wake_up(&stor_device->waiting_to_drain);
1178
1179
1180 }
1181
1182 static void storvsc_on_receive(struct hv_device *device,
1183                              struct vstor_packet *vstor_packet,
1184                              struct storvsc_cmd_request *request)
1185 {
1186         struct storvsc_scan_work *work;
1187         struct storvsc_device *stor_device;
1188
1189         switch (vstor_packet->operation) {
1190         case VSTOR_OPERATION_COMPLETE_IO:
1191                 storvsc_on_io_completion(device, vstor_packet, request);
1192                 break;
1193
1194         case VSTOR_OPERATION_REMOVE_DEVICE:
1195         case VSTOR_OPERATION_ENUMERATE_BUS:
1196                 stor_device = get_in_stor_device(device);
1197                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1198                 if (!work)
1199                         return;
1200
1201                 INIT_WORK(&work->work, storvsc_bus_scan);
1202                 work->host = stor_device->host;
1203                 schedule_work(&work->work);
1204                 break;
1205
1206         default:
1207                 break;
1208         }
1209 }
1210
1211 static void storvsc_on_channel_callback(void *context)
1212 {
1213         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1214         struct hv_device *device;
1215         struct storvsc_device *stor_device;
1216         u32 bytes_recvd;
1217         u64 request_id;
1218         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1219         struct storvsc_cmd_request *request;
1220         int ret;
1221
1222         if (channel->primary_channel != NULL)
1223                 device = channel->primary_channel->device_obj;
1224         else
1225                 device = channel->device_obj;
1226
1227         stor_device = get_in_stor_device(device);
1228         if (!stor_device)
1229                 return;
1230
1231         do {
1232                 ret = vmbus_recvpacket(channel, packet,
1233                                        ALIGN((sizeof(struct vstor_packet) -
1234                                              vmscsi_size_delta), 8),
1235                                        &bytes_recvd, &request_id);
1236                 if (ret == 0 && bytes_recvd > 0) {
1237
1238                         request = (struct storvsc_cmd_request *)
1239                                         (unsigned long)request_id;
1240
1241                         if ((request == &stor_device->init_request) ||
1242                             (request == &stor_device->reset_request)) {
1243
1244                                 memcpy(&request->vstor_packet, packet,
1245                                        (sizeof(struct vstor_packet) -
1246                                         vmscsi_size_delta));
1247                                 complete(&request->wait_event);
1248                         } else {
1249                                 storvsc_on_receive(device,
1250                                                 (struct vstor_packet *)packet,
1251                                                 request);
1252                         }
1253                 } else {
1254                         break;
1255                 }
1256         } while (1);
1257
1258         return;
1259 }
1260
1261 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1262 {
1263         struct vmstorage_channel_properties props;
1264         int ret;
1265
1266         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1267
1268         ret = vmbus_open(device->channel,
1269                          ring_size,
1270                          ring_size,
1271                          (void *)&props,
1272                          sizeof(struct vmstorage_channel_properties),
1273                          storvsc_on_channel_callback, device->channel);
1274
1275         if (ret != 0)
1276                 return ret;
1277
1278         ret = storvsc_channel_init(device);
1279
1280         return ret;
1281 }
1282
1283 static int storvsc_dev_remove(struct hv_device *device)
1284 {
1285         struct storvsc_device *stor_device;
1286         unsigned long flags;
1287
1288         stor_device = hv_get_drvdata(device);
1289
1290         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1291         stor_device->destroy = true;
1292         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1293
1294         /*
1295          * At this point, all outbound traffic should be disable. We
1296          * only allow inbound traffic (responses) to proceed so that
1297          * outstanding requests can be completed.
1298          */
1299
1300         storvsc_wait_to_drain(stor_device);
1301
1302         /*
1303          * Since we have already drained, we don't need to busy wait
1304          * as was done in final_release_stor_device()
1305          * Note that we cannot set the ext pointer to NULL until
1306          * we have drained - to drain the outgoing packets, we need to
1307          * allow incoming packets.
1308          */
1309         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1310         hv_set_drvdata(device, NULL);
1311         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1312
1313         /* Close the channel */
1314         vmbus_close(device->channel);
1315
1316         kfree(stor_device);
1317         return 0;
1318 }
1319
1320 static int storvsc_do_io(struct hv_device *device,
1321                               struct storvsc_cmd_request *request)
1322 {
1323         struct storvsc_device *stor_device;
1324         struct vstor_packet *vstor_packet;
1325         struct vmbus_channel *outgoing_channel;
1326         int ret = 0;
1327
1328         vstor_packet = &request->vstor_packet;
1329         stor_device = get_out_stor_device(device);
1330
1331         if (!stor_device)
1332                 return -ENODEV;
1333
1334
1335         request->device  = device;
1336         /*
1337          * Select an an appropriate channel to send the request out.
1338          */
1339
1340         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1341
1342
1343         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1344
1345         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1346                                         vmscsi_size_delta);
1347
1348
1349         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1350
1351
1352         vstor_packet->vm_srb.data_transfer_length =
1353         request->data_buffer.len;
1354
1355         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1356
1357         if (request->data_buffer.len) {
1358                 ret = vmbus_sendpacket_multipagebuffer(outgoing_channel,
1359                                 &request->data_buffer,
1360                                 vstor_packet,
1361                                 (sizeof(struct vstor_packet) -
1362                                 vmscsi_size_delta),
1363                                 (unsigned long)request);
1364         } else {
1365                 ret = vmbus_sendpacket(device->channel, vstor_packet,
1366                                (sizeof(struct vstor_packet) -
1367                                 vmscsi_size_delta),
1368                                (unsigned long)request,
1369                                VM_PKT_DATA_INBAND,
1370                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1371         }
1372
1373         if (ret != 0)
1374                 return ret;
1375
1376         atomic_inc(&stor_device->num_outstanding_req);
1377
1378         return ret;
1379 }
1380
1381 static int storvsc_device_alloc(struct scsi_device *sdevice)
1382 {
1383         struct stor_mem_pools *memp;
1384         int number = STORVSC_MIN_BUF_NR;
1385
1386         memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
1387         if (!memp)
1388                 return -ENOMEM;
1389
1390         memp->request_pool =
1391                 kmem_cache_create(dev_name(&sdevice->sdev_dev),
1392                                 sizeof(struct storvsc_cmd_request), 0,
1393                                 SLAB_HWCACHE_ALIGN, NULL);
1394
1395         if (!memp->request_pool)
1396                 goto err0;
1397
1398         memp->request_mempool = mempool_create(number, mempool_alloc_slab,
1399                                                 mempool_free_slab,
1400                                                 memp->request_pool);
1401
1402         if (!memp->request_mempool)
1403                 goto err1;
1404
1405         sdevice->hostdata = memp;
1406
1407         return 0;
1408
1409 err1:
1410         kmem_cache_destroy(memp->request_pool);
1411
1412 err0:
1413         kfree(memp);
1414         return -ENOMEM;
1415 }
1416
1417 static void storvsc_device_destroy(struct scsi_device *sdevice)
1418 {
1419         struct stor_mem_pools *memp = sdevice->hostdata;
1420
1421         if (!memp)
1422                 return;
1423
1424         mempool_destroy(memp->request_mempool);
1425         kmem_cache_destroy(memp->request_pool);
1426         kfree(memp);
1427         sdevice->hostdata = NULL;
1428 }
1429
1430 static int storvsc_device_configure(struct scsi_device *sdevice)
1431 {
1432         scsi_change_queue_depth(sdevice, STORVSC_MAX_IO_REQUESTS);
1433
1434         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1435
1436         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1437
1438         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1439
1440         sdevice->no_write_same = 1;
1441
1442         /*
1443          * Add blist flags to permit the reading of the VPD pages even when
1444          * the target may claim SPC-2 compliance. MSFT targets currently
1445          * claim SPC-2 compliance while they implement post SPC-2 features.
1446          * With this patch we can correctly handle WRITE_SAME_16 issues.
1447          */
1448         sdevice->sdev_bflags |= msft_blist_flags;
1449
1450         return 0;
1451 }
1452
1453 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1454                            sector_t capacity, int *info)
1455 {
1456         sector_t nsect = capacity;
1457         sector_t cylinders = nsect;
1458         int heads, sectors_pt;
1459
1460         /*
1461          * We are making up these values; let us keep it simple.
1462          */
1463         heads = 0xff;
1464         sectors_pt = 0x3f;      /* Sectors per track */
1465         sector_div(cylinders, heads * sectors_pt);
1466         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1467                 cylinders = 0xffff;
1468
1469         info[0] = heads;
1470         info[1] = sectors_pt;
1471         info[2] = (int)cylinders;
1472
1473         return 0;
1474 }
1475
1476 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1477 {
1478         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1479         struct hv_device *device = host_dev->dev;
1480
1481         struct storvsc_device *stor_device;
1482         struct storvsc_cmd_request *request;
1483         struct vstor_packet *vstor_packet;
1484         int ret, t;
1485
1486
1487         stor_device = get_out_stor_device(device);
1488         if (!stor_device)
1489                 return FAILED;
1490
1491         request = &stor_device->reset_request;
1492         vstor_packet = &request->vstor_packet;
1493
1494         init_completion(&request->wait_event);
1495
1496         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1497         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1498         vstor_packet->vm_srb.path_id = stor_device->path_id;
1499
1500         ret = vmbus_sendpacket(device->channel, vstor_packet,
1501                                (sizeof(struct vstor_packet) -
1502                                 vmscsi_size_delta),
1503                                (unsigned long)&stor_device->reset_request,
1504                                VM_PKT_DATA_INBAND,
1505                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1506         if (ret != 0)
1507                 return FAILED;
1508
1509         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1510         if (t == 0)
1511                 return TIMEOUT_ERROR;
1512
1513
1514         /*
1515          * At this point, all outstanding requests in the adapter
1516          * should have been flushed out and return to us
1517          * There is a potential race here where the host may be in
1518          * the process of responding when we return from here.
1519          * Just wait for all in-transit packets to be accounted for
1520          * before we return from here.
1521          */
1522         storvsc_wait_to_drain(stor_device);
1523
1524         return SUCCESS;
1525 }
1526
1527 /*
1528  * The host guarantees to respond to each command, although I/O latencies might
1529  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1530  * chance to perform EH.
1531  */
1532 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1533 {
1534         return BLK_EH_RESET_TIMER;
1535 }
1536
1537 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1538 {
1539         bool allowed = true;
1540         u8 scsi_op = scmnd->cmnd[0];
1541
1542         switch (scsi_op) {
1543         /* the host does not handle WRITE_SAME, log accident usage */
1544         case WRITE_SAME:
1545         /*
1546          * smartd sends this command and the host does not handle
1547          * this. So, don't send it.
1548          */
1549         case SET_WINDOW:
1550                 scmnd->result = ILLEGAL_REQUEST << 16;
1551                 allowed = false;
1552                 break;
1553         default:
1554                 break;
1555         }
1556         return allowed;
1557 }
1558
1559 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1560 {
1561         int ret;
1562         struct hv_host_device *host_dev = shost_priv(host);
1563         struct hv_device *dev = host_dev->dev;
1564         struct storvsc_cmd_request *cmd_request;
1565         unsigned int request_size = 0;
1566         int i;
1567         struct scatterlist *sgl;
1568         unsigned int sg_count = 0;
1569         struct vmscsi_request *vm_srb;
1570         struct stor_mem_pools *memp = scmnd->device->hostdata;
1571
1572         if (vmstor_current_major <= VMSTOR_WIN8_MAJOR) {
1573                 /*
1574                  * On legacy hosts filter unimplemented commands.
1575                  * Future hosts are expected to correctly handle
1576                  * unsupported commands. Furthermore, it is
1577                  * possible that some of the currently
1578                  * unsupported commands maybe supported in
1579                  * future versions of the host.
1580                  */
1581                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1582                         scmnd->scsi_done(scmnd);
1583                         return 0;
1584                 }
1585         }
1586
1587         request_size = sizeof(struct storvsc_cmd_request);
1588
1589         cmd_request = mempool_alloc(memp->request_mempool,
1590                                        GFP_ATOMIC);
1591
1592         /*
1593          * We might be invoked in an interrupt context; hence
1594          * mempool_alloc() can fail.
1595          */
1596         if (!cmd_request)
1597                 return SCSI_MLQUEUE_DEVICE_BUSY;
1598
1599         memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
1600
1601         /* Setup the cmd request */
1602         cmd_request->cmd = scmnd;
1603
1604         scmnd->host_scribble = (unsigned char *)cmd_request;
1605
1606         vm_srb = &cmd_request->vstor_packet.vm_srb;
1607         vm_srb->win8_extension.time_out_value = 60;
1608
1609         vm_srb->win8_extension.srb_flags |=
1610                 (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1611                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1612
1613         /* Build the SRB */
1614         switch (scmnd->sc_data_direction) {
1615         case DMA_TO_DEVICE:
1616                 vm_srb->data_in = WRITE_TYPE;
1617                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1618                 break;
1619         case DMA_FROM_DEVICE:
1620                 vm_srb->data_in = READ_TYPE;
1621                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1622                 break;
1623         default:
1624                 vm_srb->data_in = UNKNOWN_TYPE;
1625                 vm_srb->win8_extension.srb_flags |= (SRB_FLAGS_DATA_IN |
1626                                                      SRB_FLAGS_DATA_OUT);
1627                 break;
1628         }
1629
1630
1631         vm_srb->port_number = host_dev->port;
1632         vm_srb->path_id = scmnd->device->channel;
1633         vm_srb->target_id = scmnd->device->id;
1634         vm_srb->lun = scmnd->device->lun;
1635
1636         vm_srb->cdb_length = scmnd->cmd_len;
1637
1638         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1639
1640         cmd_request->sense_buffer = scmnd->sense_buffer;
1641
1642
1643         cmd_request->data_buffer.len = scsi_bufflen(scmnd);
1644         if (scsi_sg_count(scmnd)) {
1645                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1646                 sg_count = scsi_sg_count(scmnd);
1647
1648                 /* check if we need to bounce the sgl */
1649                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1650                         cmd_request->bounce_sgl =
1651                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1652                                                      scsi_bufflen(scmnd),
1653                                                      vm_srb->data_in);
1654                         if (!cmd_request->bounce_sgl) {
1655                                 ret = SCSI_MLQUEUE_HOST_BUSY;
1656                                 goto queue_error;
1657                         }
1658
1659                         cmd_request->bounce_sgl_count =
1660                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1661                                         PAGE_SHIFT;
1662
1663                         if (vm_srb->data_in == WRITE_TYPE)
1664                                 copy_to_bounce_buffer(sgl,
1665                                         cmd_request->bounce_sgl,
1666                                         scsi_sg_count(scmnd));
1667
1668                         sgl = cmd_request->bounce_sgl;
1669                         sg_count = cmd_request->bounce_sgl_count;
1670                 }
1671
1672                 cmd_request->data_buffer.offset = sgl[0].offset;
1673
1674                 for (i = 0; i < sg_count; i++)
1675                         cmd_request->data_buffer.pfn_array[i] =
1676                                 page_to_pfn(sg_page((&sgl[i])));
1677
1678         } else if (scsi_sglist(scmnd)) {
1679                 cmd_request->data_buffer.offset =
1680                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1681                 cmd_request->data_buffer.pfn_array[0] =
1682                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1683         }
1684
1685         /* Invokes the vsc to start an IO */
1686         ret = storvsc_do_io(dev, cmd_request);
1687
1688         if (ret == -EAGAIN) {
1689                 /* no more space */
1690
1691                 if (cmd_request->bounce_sgl_count) {
1692                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1693                                         cmd_request->bounce_sgl_count);
1694
1695                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1696                         goto queue_error;
1697                 }
1698         }
1699
1700         return 0;
1701
1702 queue_error:
1703         mempool_free(cmd_request, memp->request_mempool);
1704         scmnd->host_scribble = NULL;
1705         return ret;
1706 }
1707
1708 static struct scsi_host_template scsi_driver = {
1709         .module =               THIS_MODULE,
1710         .name =                 "storvsc_host_t",
1711         .bios_param =           storvsc_get_chs,
1712         .queuecommand =         storvsc_queuecommand,
1713         .eh_host_reset_handler =        storvsc_host_reset_handler,
1714         .eh_timed_out =         storvsc_eh_timed_out,
1715         .slave_alloc =          storvsc_device_alloc,
1716         .slave_destroy =        storvsc_device_destroy,
1717         .slave_configure =      storvsc_device_configure,
1718         .cmd_per_lun =          255,
1719         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1720         .this_id =              -1,
1721         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1722         /* currently 32 */
1723         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1724         .use_clustering =       DISABLE_CLUSTERING,
1725         /* Make sure we dont get a sg segment crosses a page boundary */
1726         .dma_boundary =         PAGE_SIZE-1,
1727         .no_write_same =        1,
1728 };
1729
1730 enum {
1731         SCSI_GUID,
1732         IDE_GUID,
1733         SFC_GUID,
1734 };
1735
1736 static const struct hv_vmbus_device_id id_table[] = {
1737         /* SCSI guid */
1738         { HV_SCSI_GUID,
1739           .driver_data = SCSI_GUID
1740         },
1741         /* IDE guid */
1742         { HV_IDE_GUID,
1743           .driver_data = IDE_GUID
1744         },
1745         /* Fibre Channel GUID */
1746         {
1747           HV_SYNTHFC_GUID,
1748           .driver_data = SFC_GUID
1749         },
1750         { },
1751 };
1752
1753 MODULE_DEVICE_TABLE(vmbus, id_table);
1754
1755 static int storvsc_probe(struct hv_device *device,
1756                         const struct hv_vmbus_device_id *dev_id)
1757 {
1758         int ret;
1759         struct Scsi_Host *host;
1760         struct hv_host_device *host_dev;
1761         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1762         int target = 0;
1763         struct storvsc_device *stor_device;
1764
1765         /*
1766          * Based on the windows host we are running on,
1767          * set state to properly communicate with the host.
1768          */
1769
1770         switch (vmbus_proto_version) {
1771         case VERSION_WS2008:
1772         case VERSION_WIN7:
1773                 sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
1774                 vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1775                 vmstor_current_major = VMSTOR_WIN7_MAJOR;
1776                 vmstor_current_minor = VMSTOR_WIN7_MINOR;
1777                 break;
1778         default:
1779                 sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
1780                 vmscsi_size_delta = 0;
1781                 vmstor_current_major = VMSTOR_WIN8_MAJOR;
1782                 vmstor_current_minor = VMSTOR_WIN8_MINOR;
1783                 break;
1784         }
1785
1786         if (dev_id->driver_data == SFC_GUID)
1787                 scsi_driver.can_queue = (STORVSC_MAX_IO_REQUESTS *
1788                                          STORVSC_FC_MAX_TARGETS);
1789         host = scsi_host_alloc(&scsi_driver,
1790                                sizeof(struct hv_host_device));
1791         if (!host)
1792                 return -ENOMEM;
1793
1794         host_dev = shost_priv(host);
1795         memset(host_dev, 0, sizeof(struct hv_host_device));
1796
1797         host_dev->port = host->host_no;
1798         host_dev->dev = device;
1799
1800
1801         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1802         if (!stor_device) {
1803                 ret = -ENOMEM;
1804                 goto err_out0;
1805         }
1806
1807         stor_device->destroy = false;
1808         stor_device->open_sub_channel = false;
1809         init_waitqueue_head(&stor_device->waiting_to_drain);
1810         stor_device->device = device;
1811         stor_device->host = host;
1812         hv_set_drvdata(device, stor_device);
1813
1814         stor_device->port_number = host->host_no;
1815         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1816         if (ret)
1817                 goto err_out1;
1818
1819         host_dev->path = stor_device->path_id;
1820         host_dev->target = stor_device->target_id;
1821
1822         switch (dev_id->driver_data) {
1823         case SFC_GUID:
1824                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1825                 host->max_id = STORVSC_FC_MAX_TARGETS;
1826                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1827                 break;
1828
1829         case SCSI_GUID:
1830                 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1831                 host->max_id = STORVSC_MAX_TARGETS;
1832                 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1833                 break;
1834
1835         default:
1836                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1837                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1838                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1839                 break;
1840         }
1841         /* max cmd length */
1842         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1843
1844         /* Register the HBA and start the scsi bus scan */
1845         ret = scsi_add_host(host, &device->device);
1846         if (ret != 0)
1847                 goto err_out2;
1848
1849         if (!dev_is_ide) {
1850                 scsi_scan_host(host);
1851         } else {
1852                 target = (device->dev_instance.b[5] << 8 |
1853                          device->dev_instance.b[4]);
1854                 ret = scsi_add_device(host, 0, target, 0);
1855                 if (ret) {
1856                         scsi_remove_host(host);
1857                         goto err_out2;
1858                 }
1859         }
1860         return 0;
1861
1862 err_out2:
1863         /*
1864          * Once we have connected with the host, we would need to
1865          * to invoke storvsc_dev_remove() to rollback this state and
1866          * this call also frees up the stor_device; hence the jump around
1867          * err_out1 label.
1868          */
1869         storvsc_dev_remove(device);
1870         goto err_out0;
1871
1872 err_out1:
1873         kfree(stor_device);
1874
1875 err_out0:
1876         scsi_host_put(host);
1877         return ret;
1878 }
1879
1880 static int storvsc_remove(struct hv_device *dev)
1881 {
1882         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1883         struct Scsi_Host *host = stor_device->host;
1884
1885         scsi_remove_host(host);
1886         storvsc_dev_remove(dev);
1887         scsi_host_put(host);
1888
1889         return 0;
1890 }
1891
1892 static struct hv_driver storvsc_drv = {
1893         .name = KBUILD_MODNAME,
1894         .id_table = id_table,
1895         .probe = storvsc_probe,
1896         .remove = storvsc_remove,
1897 };
1898
1899 static int __init storvsc_drv_init(void)
1900 {
1901         u32 max_outstanding_req_per_channel;
1902
1903         /*
1904          * Divide the ring buffer data size (which is 1 page less
1905          * than the ring buffer size since that page is reserved for
1906          * the ring buffer indices) by the max request size (which is
1907          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1908          */
1909         max_outstanding_req_per_channel =
1910                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1911                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1912                 sizeof(struct vstor_packet) + sizeof(u64) -
1913                 vmscsi_size_delta,
1914                 sizeof(u64)));
1915
1916         if (max_outstanding_req_per_channel <
1917             STORVSC_MAX_IO_REQUESTS)
1918                 return -EINVAL;
1919
1920         return vmbus_driver_register(&storvsc_drv);
1921 }
1922
1923 static void __exit storvsc_drv_exit(void)
1924 {
1925         vmbus_driver_unregister(&storvsc_drv);
1926 }
1927
1928 MODULE_LICENSE("GPL");
1929 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1930 module_init(storvsc_drv_init);
1931 module_exit(storvsc_drv_exit);