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 #define STORVSC_MAX_IO_REQUESTS                         200
 331
 332 static void storvsc_on_channel_callback(void *context);
 333
 334 /*
 335  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
 336  * reality, the path/target is not used (ie always set to 0) so our
 337  * scsi host adapter essentially has 1 bus with 1 target that contains
 338  * up to 256 luns.
 339  */
 340 #define STORVSC_MAX_LUNS_PER_TARGET                     64
 341 #define STORVSC_MAX_TARGETS                             1
 342 #define STORVSC_MAX_CHANNELS                            1
 343
 344
 345
 346 struct storvsc_cmd_request {
 347         struct list_head entry;
 348         struct scsi_cmnd *cmd;
 349
 350         unsigned int bounce_sgl_count;
 351         struct scatterlist *bounce_sgl;
 352
 353         struct hv_device *device;
 354
 355         /* Synchronize the request/response if needed */
 356         struct completion wait_event;
 357
 358         unsigned char *sense_buffer;
 359         struct hv_multipage_buffer data_buffer;
 360         struct vstor_packet vstor_packet;
 361 };
 362
 363
 364 /* A storvsc device is a device object that contains a vmbus channel */
 365 struct storvsc_device {
 366         struct hv_device *device;
 367
 368         bool     destroy;
 369         bool     drain_notify;
 370         bool     open_sub_channel;
 371         atomic_t num_outstanding_req;
 372         struct Scsi_Host *host;
 373
 374         wait_queue_head_t waiting_to_drain;
 375
 376         /*
 377          * Each unique Port/Path/Target represents 1 channel ie scsi
 378          * controller. In reality, the pathid, targetid is always 0
 379          * and the port is set by us
 380          */
 381         unsigned int port_number;
 382         unsigned char path_id;
 383         unsigned char target_id;
 384
 385         /* Used for vsc/vsp channel reset process */
 386         struct storvsc_cmd_request init_request;
 387         struct storvsc_cmd_request reset_request;
 388 };
 389
 390 struct stor_mem_pools {
 391         struct kmem_cache *request_pool;
 392         mempool_t *request_mempool;
 393 };
 394
 395 struct hv_host_device {
 396         struct hv_device *dev;
 397         unsigned int port;
 398         unsigned char path;
 399         unsigned char target;
 400 };
 401
 402 struct storvsc_scan_work {
 403         struct work_struct work;
 404         struct Scsi_Host *host;
 405         uint lun;
 406 };
 407
 408 static void storvsc_device_scan(struct work_struct *work)
 409 {
 410         struct storvsc_scan_work *wrk;
 411         uint lun;
 412         struct scsi_device *sdev;
 413
 414         wrk = container_of(work, struct storvsc_scan_work, work);
 415         lun = wrk->lun;
 416
 417         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 418         if (!sdev)
 419                 goto done;
 420         scsi_rescan_device(&sdev->sdev_gendev);
 421         scsi_device_put(sdev);
 422
 423 done:
 424         kfree(wrk);
 425 }
 426
 427 static void storvsc_bus_scan(struct work_struct *work)
 428 {
 429         struct storvsc_scan_work *wrk;
 430         int id, order_id;
 431
 432         wrk = container_of(work, struct storvsc_scan_work, work);
 433         for (id = 0; id < wrk->host->max_id; ++id) {
 434                 if (wrk->host->reverse_ordering)
 435                         order_id = wrk->host->max_id - id - 1;
 436                 else
 437                         order_id = id;
 438
 439                 scsi_scan_target(&wrk->host->shost_gendev, 0,
 440                                 order_id, SCAN_WILD_CARD, 1);
 441         }
 442         kfree(wrk);
 443 }
 444
 445 static void storvsc_remove_lun(struct work_struct *work)
 446 {
 447         struct storvsc_scan_work *wrk;
 448         struct scsi_device *sdev;
 449
 450         wrk = container_of(work, struct storvsc_scan_work, work);
 451         if (!scsi_host_get(wrk->host))
 452                 goto done;
 453
 454         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 455
 456         if (sdev) {
 457                 scsi_remove_device(sdev);
 458                 scsi_device_put(sdev);
 459         }
 460         scsi_host_put(wrk->host);
 461
 462 done:
 463         kfree(wrk);
 464 }
 465
 466 /*
 467  * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 468  * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 469  */
 470
 471 static inline u16 storvsc_get_version(u8 major, u8 minor)
 472 {
 473         u16 version;
 474
 475         version = ((major << 8) | minor);
 476         return version;
 477 }
 478
 479 /*
 480  * We can get incoming messages from the host that are not in response to
 481  * messages that we have sent out. An example of this would be messages
 482  * received by the guest to notify dynamic addition/removal of LUNs. To
 483  * deal with potential race conditions where the driver may be in the
 484  * midst of being unloaded when we might receive an unsolicited message
 485  * from the host, we have implemented a mechanism to gurantee sequential
 486  * consistency:
 487  *
 488  * 1) Once the device is marked as being destroyed, we will fail all
 489  *    outgoing messages.
 490  * 2) We permit incoming messages when the device is being destroyed,
 491  *    only to properly account for messages already sent out.
 492  */
 493
 494 static inline struct storvsc_device *get_out_stor_device(
 495                                         struct hv_device *device)
 496 {
 497         struct storvsc_device *stor_device;
 498
 499         stor_device = hv_get_drvdata(device);
 500
 501         if (stor_device && stor_device->destroy)
 502                 stor_device = NULL;
 503
 504         return stor_device;
 505 }
 506
 507
 508 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 509 {
 510         dev->drain_notify = true;
 511         wait_event(dev->waiting_to_drain,
 512                    atomic_read(&dev->num_outstanding_req) == 0);
 513         dev->drain_notify = false;
 514 }
 515
 516 static inline struct storvsc_device *get_in_stor_device(
 517                                         struct hv_device *device)
 518 {
 519         struct storvsc_device *stor_device;
 520
 521         stor_device = hv_get_drvdata(device);
 522
 523         if (!stor_device)
 524                 goto get_in_err;
 525
 526         /*
 527          * If the device is being destroyed; allow incoming
 528          * traffic only to cleanup outstanding requests.
 529          */
 530
 531         if (stor_device->destroy  &&
 532                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 533                 stor_device = NULL;
 534
 535 get_in_err:
 536         return stor_device;
 537
 538 }
 539
 540 static void destroy_bounce_buffer(struct scatterlist *sgl,
 541                                   unsigned int sg_count)
 542 {
 543         int i;
 544         struct page *page_buf;
 545
 546         for (i = 0; i < sg_count; i++) {
 547                 page_buf = sg_page((&sgl[i]));
 548                 if (page_buf != NULL)
 549                         __free_page(page_buf);
 550         }
 551
 552         kfree(sgl);
 553 }
 554
 555 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 556 {
 557         int i;
 558
 559         /* No need to check */
 560         if (sg_count < 2)
 561                 return -1;
 562
 563         /* We have at least 2 sg entries */
 564         for (i = 0; i < sg_count; i++) {
 565                 if (i == 0) {
 566                         /* make sure 1st one does not have hole */
 567                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 568                                 return i;
 569                 } else if (i == sg_count - 1) {
 570                         /* make sure last one does not have hole */
 571                         if (sgl[i].offset != 0)
 572                                 return i;
 573                 } else {
 574                         /* make sure no hole in the middle */
 575                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 576                                 return i;
 577                 }
 578         }
 579         return -1;
 580 }
 581
 582 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 583                                                 unsigned int sg_count,
 584                                                 unsigned int len,
 585                                                 int write)
 586 {
 587         int i;
 588         int num_pages;
 589         struct scatterlist *bounce_sgl;
 590         struct page *page_buf;
 591         unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 592
 593         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 594
 595         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 596         if (!bounce_sgl)
 597                 return NULL;
 598
 599         sg_init_table(bounce_sgl, num_pages);
 600         for (i = 0; i < num_pages; i++) {
 601                 page_buf = alloc_page(GFP_ATOMIC);
 602                 if (!page_buf)
 603                         goto cleanup;
 604                 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 605         }
 606
 607         return bounce_sgl;
 608
 609 cleanup:
 610         destroy_bounce_buffer(bounce_sgl, num_pages);
 611         return NULL;
 612 }
 613
 614 /* Disgusting wrapper functions */
 615 static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
 616 {
 617         void *addr = kmap_atomic(sg_page(sgl + idx));
 618         return (unsigned long)addr;
 619 }
 620
 621 static inline void sg_kunmap_atomic(unsigned long addr)
 622 {
 623         kunmap_atomic((void *)addr);
 624 }
 625
 626
 627 /* Assume the original sgl has enough room */
 628 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 629                                             struct scatterlist *bounce_sgl,
 630                                             unsigned int orig_sgl_count,
 631                                             unsigned int bounce_sgl_count)
 632 {
 633         int i;
 634         int j = 0;
 635         unsigned long src, dest;
 636         unsigned int srclen, destlen, copylen;
 637         unsigned int total_copied = 0;
 638         unsigned long bounce_addr = 0;
 639         unsigned long dest_addr = 0;
 640         unsigned long flags;
 641
 642         local_irq_save(flags);
 643
 644         for (i = 0; i < orig_sgl_count; i++) {
 645                 dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 646                 dest = dest_addr;
 647                 destlen = orig_sgl[i].length;
 648
 649                 if (bounce_addr == 0)
 650                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 651
 652                 while (destlen) {
 653                         src = bounce_addr + bounce_sgl[j].offset;
 654                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 655
 656                         copylen = min(srclen, destlen);
 657                         memcpy((void *)dest, (void *)src, copylen);
 658
 659                         total_copied += copylen;
 660                         bounce_sgl[j].offset += copylen;
 661                         destlen -= copylen;
 662                         dest += copylen;
 663
 664                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 665                                 /* full */
 666                                 sg_kunmap_atomic(bounce_addr);
 667                                 j++;
 668
 669                                 /*
 670                                  * It is possible that the number of elements
 671                                  * in the bounce buffer may not be equal to
 672                                  * the number of elements in the original
 673                                  * scatter list. Handle this correctly.
 674                                  */
 675
 676                                 if (j == bounce_sgl_count) {
 677                                         /*
 678                                          * We are done; cleanup and return.
 679                                          */
 680                                         sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 681                                         local_irq_restore(flags);
 682                                         return total_copied;
 683                                 }
 684
 685                                 /* if we need to use another bounce buffer */
 686                                 if (destlen || i != orig_sgl_count - 1)
 687                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 688                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 689                                 /* unmap the last bounce that is < PAGE_SIZE */
 690                                 sg_kunmap_atomic(bounce_addr);
 691                         }
 692                 }
 693
 694                 sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 695         }
 696
 697         local_irq_restore(flags);
 698
 699         return total_copied;
 700 }
 701
 702 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 703 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 704                                           struct scatterlist *bounce_sgl,
 705                                           unsigned int orig_sgl_count)
 706 {
 707         int i;
 708         int j = 0;
 709         unsigned long src, dest;
 710         unsigned int srclen, destlen, copylen;
 711         unsigned int total_copied = 0;
 712         unsigned long bounce_addr = 0;
 713         unsigned long src_addr = 0;
 714         unsigned long flags;
 715
 716         local_irq_save(flags);
 717
 718         for (i = 0; i < orig_sgl_count; i++) {
 719                 src_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 720                 src = src_addr;
 721                 srclen = orig_sgl[i].length;
 722
 723                 if (bounce_addr == 0)
 724                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 725
 726                 while (srclen) {
 727                         /* assume bounce offset always == 0 */
 728                         dest = bounce_addr + bounce_sgl[j].length;
 729                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 730
 731                         copylen = min(srclen, destlen);
 732                         memcpy((void *)dest, (void *)src, copylen);
 733
 734                         total_copied += copylen;
 735                         bounce_sgl[j].length += copylen;
 736                         srclen -= copylen;
 737                         src += copylen;
 738
 739                         if (bounce_sgl[j].length == PAGE_SIZE) {
 740                                 /* full..move to next entry */
 741                                 sg_kunmap_atomic(bounce_addr);
 742                                 j++;
 743
 744                                 /* if we need to use another bounce buffer */
 745                                 if (srclen || i != orig_sgl_count - 1)
 746                                         bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 747
 748                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 749                                 /* unmap the last bounce that is < PAGE_SIZE */
 750                                 sg_kunmap_atomic(bounce_addr);
 751                         }
 752                 }
 753
 754                 sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
 755         }
 756
 757         local_irq_restore(flags);
 758
 759         return total_copied;
 760 }
 761
 762 static void handle_sc_creation(struct vmbus_channel *new_sc)
 763 {
 764         struct hv_device *device = new_sc->primary_channel->device_obj;
 765         struct storvsc_device *stor_device;
 766         struct vmstorage_channel_properties props;
 767
 768         stor_device = get_out_stor_device(device);
 769         if (!stor_device)
 770                 return;
 771
 772         if (stor_device->open_sub_channel == false)
 773                 return;
 774
 775         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 776
 777         vmbus_open(new_sc,
 778                    storvsc_ringbuffer_size,
 779                    storvsc_ringbuffer_size,
 780                    (void *)&props,
 781                    sizeof(struct vmstorage_channel_properties),
 782                    storvsc_on_channel_callback, new_sc);
 783 }
 784
 785 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 786 {
 787         struct storvsc_device *stor_device;
 788         int num_cpus = num_online_cpus();
 789         int num_sc;
 790         struct storvsc_cmd_request *request;
 791         struct vstor_packet *vstor_packet;
 792         int ret, t;
 793
 794         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 795         stor_device = get_out_stor_device(device);
 796         if (!stor_device)
 797                 return;
 798
 799         request = &stor_device->init_request;
 800         vstor_packet = &request->vstor_packet;
 801
 802         stor_device->open_sub_channel = true;
 803         /*
 804          * Establish a handler for dealing with subchannels.
 805          */
 806         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 807
 808         /*
 809          * Check to see if sub-channels have already been created. This
 810          * can happen when this driver is re-loaded after unloading.
 811          */
 812
 813         if (vmbus_are_subchannels_present(device->channel))
 814                 return;
 815
 816         stor_device->open_sub_channel = false;
 817         /*
 818          * Request the host to create sub-channels.
 819          */
 820         memset(request, 0, sizeof(struct storvsc_cmd_request));
 821         init_completion(&request->wait_event);
 822         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 823         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 824         vstor_packet->sub_channel_count = num_sc;
 825
 826         ret = vmbus_sendpacket(device->channel, vstor_packet,
 827                                (sizeof(struct vstor_packet) -
 828                                vmscsi_size_delta),
 829                                (unsigned long)request,
 830                                VM_PKT_DATA_INBAND,
 831                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 832
 833         if (ret != 0)
 834                 return;
 835
 836         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 837         if (t == 0)
 838                 return;
 839
 840         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 841             vstor_packet->status != 0)
 842                 return;
 843
 844         /*
 845          * Now that we created the sub-channels, invoke the check; this
 846          * may trigger the callback.
 847          */
 848         stor_device->open_sub_channel = true;
 849         vmbus_are_subchannels_present(device->channel);
 850 }
 851
 852 static int storvsc_channel_init(struct hv_device *device)
 853 {
 854         struct storvsc_device *stor_device;
 855         struct storvsc_cmd_request *request;
 856         struct vstor_packet *vstor_packet;
 857         int ret, t;
 858         int max_chns;
 859         bool process_sub_channels = false;
 860
 861         stor_device = get_out_stor_device(device);
 862         if (!stor_device)
 863                 return -ENODEV;
 864
 865         request = &stor_device->init_request;
 866         vstor_packet = &request->vstor_packet;
 867
 868         /*
 869          * Now, initiate the vsc/vsp initialization protocol on the open
 870          * channel
 871          */
 872         memset(request, 0, sizeof(struct storvsc_cmd_request));
 873         init_completion(&request->wait_event);
 874         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 875         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 876
 877         ret = vmbus_sendpacket(device->channel, vstor_packet,
 878                                (sizeof(struct vstor_packet) -
 879                                vmscsi_size_delta),
 880                                (unsigned long)request,
 881                                VM_PKT_DATA_INBAND,
 882                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 883         if (ret != 0)
 884                 goto cleanup;
 885
 886         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 887         if (t == 0) {
 888                 ret = -ETIMEDOUT;
 889                 goto cleanup;
 890         }
 891
 892         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 893             vstor_packet->status != 0)
 894                 goto cleanup;
 895
 896
 897         /* reuse the packet for version range supported */
 898         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 899         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 900         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 901
 902         vstor_packet->version.major_minor =
 903                 storvsc_get_version(vmstor_current_major, vmstor_current_minor);
 904
 905         /*
 906          * The revision number is only used in Windows; set it to 0.
 907          */
 908         vstor_packet->version.revision = 0;
 909
 910         ret = vmbus_sendpacket(device->channel, vstor_packet,
 911                                (sizeof(struct vstor_packet) -
 912                                 vmscsi_size_delta),
 913                                (unsigned long)request,
 914                                VM_PKT_DATA_INBAND,
 915                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 916         if (ret != 0)
 917                 goto cleanup;
 918
 919         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 920         if (t == 0) {
 921                 ret = -ETIMEDOUT;
 922                 goto cleanup;
 923         }
 924
 925         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 926             vstor_packet->status != 0)
 927                 goto cleanup;
 928
 929
 930         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 931         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 932         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 933
 934         ret = vmbus_sendpacket(device->channel, vstor_packet,
 935                                (sizeof(struct vstor_packet) -
 936                                 vmscsi_size_delta),
 937                                (unsigned long)request,
 938                                VM_PKT_DATA_INBAND,
 939                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 940
 941         if (ret != 0)
 942                 goto cleanup;
 943
 944         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 945         if (t == 0) {
 946                 ret = -ETIMEDOUT;
 947                 goto cleanup;
 948         }
 949
 950         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 951             vstor_packet->status != 0)
 952                 goto cleanup;
 953
 954         /*
 955          * Check to see if multi-channel support is there.
 956          * Hosts that implement protocol version of 5.1 and above
 957          * support multi-channel.
 958          */
 959         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 960         if ((vmbus_proto_version != VERSION_WIN7) &&
 961            (vmbus_proto_version != VERSION_WS2008))  {
 962                 if (vstor_packet->storage_channel_properties.flags &
 963                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 964                         process_sub_channels = true;
 965         }
 966
 967         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 968         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 969         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 970
 971         ret = vmbus_sendpacket(device->channel, vstor_packet,
 972                                (sizeof(struct vstor_packet) -
 973                                 vmscsi_size_delta),
 974                                (unsigned long)request,
 975                                VM_PKT_DATA_INBAND,
 976                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 977
 978         if (ret != 0)
 979                 goto cleanup;
 980
 981         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 982         if (t == 0) {
 983                 ret = -ETIMEDOUT;
 984                 goto cleanup;
 985         }
 986
 987         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 988             vstor_packet->status != 0)
 989                 goto cleanup;
 990
 991         if (process_sub_channels)
 992                 handle_multichannel_storage(device, max_chns);
 993
 994
 995 cleanup:
 996         return ret;
 997 }
 998
 999 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1000                                 struct scsi_cmnd *scmnd,
1001                                 struct Scsi_Host *host,
1002                                 u8 asc, u8 ascq)
1003 {
1004         struct storvsc_scan_work *wrk;
1005         void (*process_err_fn)(struct work_struct *work);
1006         bool do_work = false;
1007
1008         switch (vm_srb->srb_status) {
1009         case SRB_STATUS_ERROR:
1010                 /*
1011                  * If there is an error; offline the device since all
1012                  * error recovery strategies would have already been
1013                  * deployed on the host side. However, if the command
1014                  * were a pass-through command deal with it appropriately.
1015                  */
1016                 switch (scmnd->cmnd[0]) {
1017                 case ATA_16:
1018                 case ATA_12:
1019                         set_host_byte(scmnd, DID_PASSTHROUGH);
1020                         break;
1021                 default:
1022                         set_host_byte(scmnd, DID_TARGET_FAILURE);
1023                 }
1024                 break;
1025         case SRB_STATUS_INVALID_LUN:
1026                 do_work = true;
1027                 process_err_fn = storvsc_remove_lun;
1028                 break;
1029         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
1030                 if ((asc == 0x2a) && (ascq == 0x9)) {
1031                         do_work = true;
1032                         process_err_fn = storvsc_device_scan;
1033                         /*
1034                          * Retry the I/O that trigerred this.
1035                          */
1036                         set_host_byte(scmnd, DID_REQUEUE);
1037                 }
1038                 break;
1039         }
1040
1041         if (!do_work)
1042                 return;
1043
1044         /*
1045          * We need to schedule work to process this error; schedule it.
1046          */
1047         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1048         if (!wrk) {
1049                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1050                 return;
1051         }
1052
1053         wrk->host = host;
1054         wrk->lun = vm_srb->lun;
1055         INIT_WORK(&wrk->work, process_err_fn);
1056         schedule_work(&wrk->work);
1057 }
1058
1059
1060 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
1061 {
1062         struct scsi_cmnd *scmnd = cmd_request->cmd;
1063         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1064         void (*scsi_done_fn)(struct scsi_cmnd *);
1065         struct scsi_sense_hdr sense_hdr;
1066         struct vmscsi_request *vm_srb;
1067         struct stor_mem_pools *memp = scmnd->device->hostdata;
1068         struct Scsi_Host *host;
1069         struct storvsc_device *stor_dev;
1070         struct hv_device *dev = host_dev->dev;
1071
1072         stor_dev = get_in_stor_device(dev);
1073         host = stor_dev->host;
1074
1075         vm_srb = &cmd_request->vstor_packet.vm_srb;
1076         if (cmd_request->bounce_sgl_count) {
1077                 if (vm_srb->data_in == READ_TYPE)
1078                         copy_from_bounce_buffer(scsi_sglist(scmnd),
1079                                         cmd_request->bounce_sgl,
1080                                         scsi_sg_count(scmnd),
1081                                         cmd_request->bounce_sgl_count);
1082                 destroy_bounce_buffer(cmd_request->bounce_sgl,
1083                                         cmd_request->bounce_sgl_count);
1084         }
1085
1086         scmnd->result = vm_srb->scsi_status;
1087
1088         if (scmnd->result) {
1089                 if (scsi_normalize_sense(scmnd->sense_buffer,
1090                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1091                         scsi_print_sense_hdr("storvsc", &sense_hdr);
1092         }
1093
1094         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
1095                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1096                                          sense_hdr.ascq);
1097
1098         scsi_set_resid(scmnd,
1099                 cmd_request->data_buffer.len -
1100                 vm_srb->data_transfer_length);
1101
1102         scsi_done_fn = scmnd->scsi_done;
1103
1104         scmnd->host_scribble = NULL;
1105         scmnd->scsi_done = NULL;
1106
1107         scsi_done_fn(scmnd);
1108
1109         mempool_free(cmd_request, memp->request_mempool);
1110 }
1111
1112 static void storvsc_on_io_completion(struct hv_device *device,
1113                                   struct vstor_packet *vstor_packet,
1114                                   struct storvsc_cmd_request *request)
1115 {
1116         struct storvsc_device *stor_device;
1117         struct vstor_packet *stor_pkt;
1118
1119         stor_device = hv_get_drvdata(device);
1120         stor_pkt = &request->vstor_packet;
1121
1122         /*
1123          * The current SCSI handling on the host side does
1124          * not correctly handle:
1125          * INQUIRY command with page code parameter set to 0x80
1126          * MODE_SENSE command with cmd[2] == 0x1c
1127          *
1128          * Setup srb and scsi status so this won't be fatal.
1129          * We do this so we can distinguish truly fatal failues
1130          * (srb status == 0x4) and off-line the device in that case.
1131          */
1132
1133         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1134            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1135                 vstor_packet->vm_srb.scsi_status = 0;
1136                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1137         }
1138
1139
1140         /* Copy over the status...etc */
1141         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1142         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1143         stor_pkt->vm_srb.sense_info_length =
1144         vstor_packet->vm_srb.sense_info_length;
1145
1146         if (vstor_packet->vm_srb.scsi_status != 0 ||
1147                 vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS){
1148                 dev_warn(&device->device,
1149                          "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1150                          stor_pkt->vm_srb.cdb[0],
1151                          vstor_packet->vm_srb.scsi_status,
1152                          vstor_packet->vm_srb.srb_status);
1153         }
1154
1155         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1156                 /* CHECK_CONDITION */
1157                 if (vstor_packet->vm_srb.srb_status &
1158                         SRB_STATUS_AUTOSENSE_VALID) {
1159                         /* autosense data available */
1160                         dev_warn(&device->device,
1161                                  "stor pkt %p autosense data valid - len %d\n",
1162                                  request,
1163                                  vstor_packet->vm_srb.sense_info_length);
1164
1165                         memcpy(request->sense_buffer,
1166                                vstor_packet->vm_srb.sense_data,
1167                                vstor_packet->vm_srb.sense_info_length);
1168
1169                 }
1170         }
1171
1172         stor_pkt->vm_srb.data_transfer_length =
1173         vstor_packet->vm_srb.data_transfer_length;
1174
1175         storvsc_command_completion(request);
1176
1177         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1178                 stor_device->drain_notify)
1179                 wake_up(&stor_device->waiting_to_drain);
1180
1181
1182 }
1183
1184 static void storvsc_on_receive(struct hv_device *device,
1185                              struct vstor_packet *vstor_packet,
1186                              struct storvsc_cmd_request *request)
1187 {
1188         struct storvsc_scan_work *work;
1189         struct storvsc_device *stor_device;
1190
1191         switch (vstor_packet->operation) {
1192         case VSTOR_OPERATION_COMPLETE_IO:
1193                 storvsc_on_io_completion(device, vstor_packet, request);
1194                 break;
1195
1196         case VSTOR_OPERATION_REMOVE_DEVICE:
1197         case VSTOR_OPERATION_ENUMERATE_BUS:
1198                 stor_device = get_in_stor_device(device);
1199                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1200                 if (!work)
1201                         return;
1202
1203                 INIT_WORK(&work->work, storvsc_bus_scan);
1204                 work->host = stor_device->host;
1205                 schedule_work(&work->work);
1206                 break;
1207
1208         default:
1209                 break;
1210         }
1211 }
1212
1213 static void storvsc_on_channel_callback(void *context)
1214 {
1215         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1216         struct hv_device *device;
1217         struct storvsc_device *stor_device;
1218         u32 bytes_recvd;
1219         u64 request_id;
1220         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1221         struct storvsc_cmd_request *request;
1222         int ret;
1223
1224         if (channel->primary_channel != NULL)
1225                 device = channel->primary_channel->device_obj;
1226         else
1227                 device = channel->device_obj;
1228
1229         stor_device = get_in_stor_device(device);
1230         if (!stor_device)
1231                 return;
1232
1233         do {
1234                 ret = vmbus_recvpacket(channel, packet,
1235                                        ALIGN((sizeof(struct vstor_packet) -
1236                                              vmscsi_size_delta), 8),
1237                                        &bytes_recvd, &request_id);
1238                 if (ret == 0 && bytes_recvd > 0) {
1239
1240                         request = (struct storvsc_cmd_request *)
1241                                         (unsigned long)request_id;
1242
1243                         if ((request == &stor_device->init_request) ||
1244                             (request == &stor_device->reset_request)) {
1245
1246                                 memcpy(&request->vstor_packet, packet,
1247                                        (sizeof(struct vstor_packet) -
1248                                         vmscsi_size_delta));
1249                                 complete(&request->wait_event);
1250                         } else {
1251                                 storvsc_on_receive(device,
1252                                                 (struct vstor_packet *)packet,
1253                                                 request);
1254                         }
1255                 } else {
1256                         break;
1257                 }
1258         } while (1);
1259
1260         return;
1261 }
1262
1263 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1264 {
1265         struct vmstorage_channel_properties props;
1266         int ret;
1267
1268         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1269
1270         ret = vmbus_open(device->channel,
1271                          ring_size,
1272                          ring_size,
1273                          (void *)&props,
1274                          sizeof(struct vmstorage_channel_properties),
1275                          storvsc_on_channel_callback, device->channel);
1276
1277         if (ret != 0)
1278                 return ret;
1279
1280         ret = storvsc_channel_init(device);
1281
1282         return ret;
1283 }
1284
1285 static int storvsc_dev_remove(struct hv_device *device)
1286 {
1287         struct storvsc_device *stor_device;
1288         unsigned long flags;
1289
1290         stor_device = hv_get_drvdata(device);
1291
1292         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1293         stor_device->destroy = true;
1294         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1295
1296         /*
1297          * At this point, all outbound traffic should be disable. We
1298          * only allow inbound traffic (responses) to proceed so that
1299          * outstanding requests can be completed.
1300          */
1301
1302         storvsc_wait_to_drain(stor_device);
1303
1304         /*
1305          * Since we have already drained, we don't need to busy wait
1306          * as was done in final_release_stor_device()
1307          * Note that we cannot set the ext pointer to NULL until
1308          * we have drained - to drain the outgoing packets, we need to
1309          * allow incoming packets.
1310          */
1311         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1312         hv_set_drvdata(device, NULL);
1313         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1314
1315         /* Close the channel */
1316         vmbus_close(device->channel);
1317
1318         kfree(stor_device);
1319         return 0;
1320 }
1321
1322 static int storvsc_do_io(struct hv_device *device,
1323                               struct storvsc_cmd_request *request)
1324 {
1325         struct storvsc_device *stor_device;
1326         struct vstor_packet *vstor_packet;
1327         struct vmbus_channel *outgoing_channel;
1328         int ret = 0;
1329
1330         vstor_packet = &request->vstor_packet;
1331         stor_device = get_out_stor_device(device);
1332
1333         if (!stor_device)
1334                 return -ENODEV;
1335
1336
1337         request->device  = device;
1338         /*
1339          * Select an an appropriate channel to send the request out.
1340          */
1341
1342         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1343
1344
1345         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1346
1347         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1348                                         vmscsi_size_delta);
1349
1350
1351         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1352
1353
1354         vstor_packet->vm_srb.data_transfer_length =
1355         request->data_buffer.len;
1356
1357         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1358
1359         if (request->data_buffer.len) {
1360                 ret = vmbus_sendpacket_multipagebuffer(outgoing_channel,
1361                                 &request->data_buffer,
1362                                 vstor_packet,
1363                                 (sizeof(struct vstor_packet) -
1364                                 vmscsi_size_delta),
1365                                 (unsigned long)request);
1366         } else {
1367                 ret = vmbus_sendpacket(device->channel, vstor_packet,
1368                                (sizeof(struct vstor_packet) -
1369                                 vmscsi_size_delta),
1370                                (unsigned long)request,
1371                                VM_PKT_DATA_INBAND,
1372                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1373         }
1374
1375         if (ret != 0)
1376                 return ret;
1377
1378         atomic_inc(&stor_device->num_outstanding_req);
1379
1380         return ret;
1381 }
1382
1383 static int storvsc_device_alloc(struct scsi_device *sdevice)
1384 {
1385         struct stor_mem_pools *memp;
1386         int number = STORVSC_MIN_BUF_NR;
1387
1388         memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
1389         if (!memp)
1390                 return -ENOMEM;
1391
1392         memp->request_pool =
1393                 kmem_cache_create(dev_name(&sdevice->sdev_dev),
1394                                 sizeof(struct storvsc_cmd_request), 0,
1395                                 SLAB_HWCACHE_ALIGN, NULL);
1396
1397         if (!memp->request_pool)
1398                 goto err0;
1399
1400         memp->request_mempool = mempool_create(number, mempool_alloc_slab,
1401                                                 mempool_free_slab,
1402                                                 memp->request_pool);
1403
1404         if (!memp->request_mempool)
1405                 goto err1;
1406
1407         sdevice->hostdata = memp;
1408
1409         return 0;
1410
1411 err1:
1412         kmem_cache_destroy(memp->request_pool);
1413
1414 err0:
1415         kfree(memp);
1416         return -ENOMEM;
1417 }
1418
1419 static void storvsc_device_destroy(struct scsi_device *sdevice)
1420 {
1421         struct stor_mem_pools *memp = sdevice->hostdata;
1422
1423         if (!memp)
1424                 return;
1425
1426         mempool_destroy(memp->request_mempool);
1427         kmem_cache_destroy(memp->request_pool);
1428         kfree(memp);
1429         sdevice->hostdata = NULL;
1430 }
1431
1432 static int storvsc_device_configure(struct scsi_device *sdevice)
1433 {
1434         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
1435                                 STORVSC_MAX_IO_REQUESTS);
1436
1437         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1438
1439         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1440
1441         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1442
1443         sdevice->no_write_same = 1;
1444
1445         return 0;
1446 }
1447
1448 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1449                            sector_t capacity, int *info)
1450 {
1451         sector_t nsect = capacity;
1452         sector_t cylinders = nsect;
1453         int heads, sectors_pt;
1454
1455         /*
1456          * We are making up these values; let us keep it simple.
1457          */
1458         heads = 0xff;
1459         sectors_pt = 0x3f;      /* Sectors per track */
1460         sector_div(cylinders, heads * sectors_pt);
1461         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1462                 cylinders = 0xffff;
1463
1464         info[0] = heads;
1465         info[1] = sectors_pt;
1466         info[2] = (int)cylinders;
1467
1468         return 0;
1469 }
1470
1471 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1472 {
1473         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1474         struct hv_device *device = host_dev->dev;
1475
1476         struct storvsc_device *stor_device;
1477         struct storvsc_cmd_request *request;
1478         struct vstor_packet *vstor_packet;
1479         int ret, t;
1480
1481
1482         stor_device = get_out_stor_device(device);
1483         if (!stor_device)
1484                 return FAILED;
1485
1486         request = &stor_device->reset_request;
1487         vstor_packet = &request->vstor_packet;
1488
1489         init_completion(&request->wait_event);
1490
1491         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1492         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1493         vstor_packet->vm_srb.path_id = stor_device->path_id;
1494
1495         ret = vmbus_sendpacket(device->channel, vstor_packet,
1496                                (sizeof(struct vstor_packet) -
1497                                 vmscsi_size_delta),
1498                                (unsigned long)&stor_device->reset_request,
1499                                VM_PKT_DATA_INBAND,
1500                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1501         if (ret != 0)
1502                 return FAILED;
1503
1504         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1505         if (t == 0)
1506                 return TIMEOUT_ERROR;
1507
1508
1509         /*
1510          * At this point, all outstanding requests in the adapter
1511          * should have been flushed out and return to us
1512          * There is a potential race here where the host may be in
1513          * the process of responding when we return from here.
1514          * Just wait for all in-transit packets to be accounted for
1515          * before we return from here.
1516          */
1517         storvsc_wait_to_drain(stor_device);
1518
1519         return SUCCESS;
1520 }
1521
1522 /*
1523  * The host guarantees to respond to each command, although I/O latencies might
1524  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1525  * chance to perform EH.
1526  */
1527 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1528 {
1529         return BLK_EH_RESET_TIMER;
1530 }
1531
1532 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1533 {
1534         bool allowed = true;
1535         u8 scsi_op = scmnd->cmnd[0];
1536
1537         switch (scsi_op) {
1538         /* the host does not handle WRITE_SAME, log accident usage */
1539         case WRITE_SAME:
1540         /*
1541          * smartd sends this command and the host does not handle
1542          * this. So, don't send it.
1543          */
1544         case SET_WINDOW:
1545                 scmnd->result = ILLEGAL_REQUEST << 16;
1546                 allowed = false;
1547                 break;
1548         default:
1549                 break;
1550         }
1551         return allowed;
1552 }
1553
1554 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1555 {
1556         int ret;
1557         struct hv_host_device *host_dev = shost_priv(host);
1558         struct hv_device *dev = host_dev->dev;
1559         struct storvsc_cmd_request *cmd_request;
1560         unsigned int request_size = 0;
1561         int i;
1562         struct scatterlist *sgl;
1563         unsigned int sg_count = 0;
1564         struct vmscsi_request *vm_srb;
1565         struct stor_mem_pools *memp = scmnd->device->hostdata;
1566
1567         if (!storvsc_scsi_cmd_ok(scmnd)) {
1568                 scmnd->scsi_done(scmnd);
1569                 return 0;
1570         }
1571
1572         request_size = sizeof(struct storvsc_cmd_request);
1573
1574         cmd_request = mempool_alloc(memp->request_mempool,
1575                                        GFP_ATOMIC);
1576
1577         /*
1578          * We might be invoked in an interrupt context; hence
1579          * mempool_alloc() can fail.
1580          */
1581         if (!cmd_request)
1582                 return SCSI_MLQUEUE_DEVICE_BUSY;
1583
1584         memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
1585
1586         /* Setup the cmd request */
1587         cmd_request->cmd = scmnd;
1588
1589         scmnd->host_scribble = (unsigned char *)cmd_request;
1590
1591         vm_srb = &cmd_request->vstor_packet.vm_srb;
1592         vm_srb->win8_extension.time_out_value = 60;
1593
1594
1595         /* Build the SRB */
1596         switch (scmnd->sc_data_direction) {
1597         case DMA_TO_DEVICE:
1598                 vm_srb->data_in = WRITE_TYPE;
1599                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1600                 vm_srb->win8_extension.srb_flags |=
1601                         (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1602                         SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1603                 break;
1604         case DMA_FROM_DEVICE:
1605                 vm_srb->data_in = READ_TYPE;
1606                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1607                 vm_srb->win8_extension.srb_flags |=
1608                         (SRB_FLAGS_QUEUE_ACTION_ENABLE |
1609                         SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1610                 break;
1611         default:
1612                 vm_srb->data_in = UNKNOWN_TYPE;
1613                 vm_srb->win8_extension.srb_flags = 0;
1614                 break;
1615         }
1616
1617
1618         vm_srb->port_number = host_dev->port;
1619         vm_srb->path_id = scmnd->device->channel;
1620         vm_srb->target_id = scmnd->device->id;
1621         vm_srb->lun = scmnd->device->lun;
1622
1623         vm_srb->cdb_length = scmnd->cmd_len;
1624
1625         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1626
1627         cmd_request->sense_buffer = scmnd->sense_buffer;
1628
1629
1630         cmd_request->data_buffer.len = scsi_bufflen(scmnd);
1631         if (scsi_sg_count(scmnd)) {
1632                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1633                 sg_count = scsi_sg_count(scmnd);
1634
1635                 /* check if we need to bounce the sgl */
1636                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1637                         cmd_request->bounce_sgl =
1638                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1639                                                      scsi_bufflen(scmnd),
1640                                                      vm_srb->data_in);
1641                         if (!cmd_request->bounce_sgl) {
1642                                 ret = SCSI_MLQUEUE_HOST_BUSY;
1643                                 goto queue_error;
1644                         }
1645
1646                         cmd_request->bounce_sgl_count =
1647                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1648                                         PAGE_SHIFT;
1649
1650                         if (vm_srb->data_in == WRITE_TYPE)
1651                                 copy_to_bounce_buffer(sgl,
1652                                         cmd_request->bounce_sgl,
1653                                         scsi_sg_count(scmnd));
1654
1655                         sgl = cmd_request->bounce_sgl;
1656                         sg_count = cmd_request->bounce_sgl_count;
1657                 }
1658
1659                 cmd_request->data_buffer.offset = sgl[0].offset;
1660
1661                 for (i = 0; i < sg_count; i++)
1662                         cmd_request->data_buffer.pfn_array[i] =
1663                                 page_to_pfn(sg_page((&sgl[i])));
1664
1665         } else if (scsi_sglist(scmnd)) {
1666                 cmd_request->data_buffer.offset =
1667                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1668                 cmd_request->data_buffer.pfn_array[0] =
1669                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1670         }
1671
1672         /* Invokes the vsc to start an IO */
1673         ret = storvsc_do_io(dev, cmd_request);
1674
1675         if (ret == -EAGAIN) {
1676                 /* no more space */
1677
1678                 if (cmd_request->bounce_sgl_count) {
1679                         destroy_bounce_buffer(cmd_request->bounce_sgl,
1680                                         cmd_request->bounce_sgl_count);
1681
1682                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1683                         goto queue_error;
1684                 }
1685         }
1686
1687         return 0;
1688
1689 queue_error:
1690         mempool_free(cmd_request, memp->request_mempool);
1691         scmnd->host_scribble = NULL;
1692         return ret;
1693 }
1694
1695 static struct scsi_host_template scsi_driver = {
1696         .module =               THIS_MODULE,
1697         .name =                 "storvsc_host_t",
1698         .bios_param =           storvsc_get_chs,
1699         .queuecommand =         storvsc_queuecommand,
1700         .eh_host_reset_handler =        storvsc_host_reset_handler,
1701         .eh_timed_out =         storvsc_eh_timed_out,
1702         .slave_alloc =          storvsc_device_alloc,
1703         .slave_destroy =        storvsc_device_destroy,
1704         .slave_configure =      storvsc_device_configure,
1705         .cmd_per_lun =          1,
1706         /* 64 max_queue * 1 target */
1707         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1708         .this_id =              -1,
1709         /* no use setting to 0 since ll_blk_rw reset it to 1 */
1710         /* currently 32 */
1711         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1712         .use_clustering =       DISABLE_CLUSTERING,
1713         /* Make sure we dont get a sg segment crosses a page boundary */
1714         .dma_boundary =         PAGE_SIZE-1,
1715         .no_write_same =        1,
1716 };
1717
1718 enum {
1719         SCSI_GUID,
1720         IDE_GUID,
1721         SFC_GUID,
1722 };
1723
1724 static const struct hv_vmbus_device_id id_table[] = {
1725         /* SCSI guid */
1726         { HV_SCSI_GUID,
1727           .driver_data = SCSI_GUID
1728         },
1729         /* IDE guid */
1730         { HV_IDE_GUID,
1731           .driver_data = IDE_GUID
1732         },
1733         /* Fibre Channel GUID */
1734         {
1735           HV_SYNTHFC_GUID,
1736           .driver_data = SFC_GUID
1737         },
1738         { },
1739 };
1740
1741 MODULE_DEVICE_TABLE(vmbus, id_table);
1742
1743 static int storvsc_probe(struct hv_device *device,
1744                         const struct hv_vmbus_device_id *dev_id)
1745 {
1746         int ret;
1747         struct Scsi_Host *host;
1748         struct hv_host_device *host_dev;
1749         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1750         int target = 0;
1751         struct storvsc_device *stor_device;
1752
1753         /*
1754          * Based on the windows host we are running on,
1755          * set state to properly communicate with the host.
1756          */
1757
1758         if (vmbus_proto_version == VERSION_WIN8) {
1759                 sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
1760                 vmscsi_size_delta = 0;
1761                 vmstor_current_major = VMSTOR_WIN8_MAJOR;
1762                 vmstor_current_minor = VMSTOR_WIN8_MINOR;
1763         } else {
1764                 sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
1765                 vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1766                 vmstor_current_major = VMSTOR_WIN7_MAJOR;
1767                 vmstor_current_minor = VMSTOR_WIN7_MINOR;
1768         }
1769
1770
1771         host = scsi_host_alloc(&scsi_driver,
1772                                sizeof(struct hv_host_device));
1773         if (!host)
1774                 return -ENOMEM;
1775
1776         host_dev = shost_priv(host);
1777         memset(host_dev, 0, sizeof(struct hv_host_device));
1778
1779         host_dev->port = host->host_no;
1780         host_dev->dev = device;
1781
1782
1783         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1784         if (!stor_device) {
1785                 ret = -ENOMEM;
1786                 goto err_out0;
1787         }
1788
1789         stor_device->destroy = false;
1790         stor_device->open_sub_channel = false;
1791         init_waitqueue_head(&stor_device->waiting_to_drain);
1792         stor_device->device = device;
1793         stor_device->host = host;
1794         hv_set_drvdata(device, stor_device);
1795
1796         stor_device->port_number = host->host_no;
1797         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1798         if (ret)
1799                 goto err_out1;
1800
1801         host_dev->path = stor_device->path_id;
1802         host_dev->target = stor_device->target_id;
1803
1804         /* max # of devices per target */
1805         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1806         /* max # of targets per channel */
1807         host->max_id = STORVSC_MAX_TARGETS;
1808         /* max # of channels */
1809         host->max_channel = STORVSC_MAX_CHANNELS - 1;
1810         /* max cmd length */
1811         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1812
1813         /* Register the HBA and start the scsi bus scan */
1814         ret = scsi_add_host(host, &device->device);
1815         if (ret != 0)
1816                 goto err_out2;
1817
1818         if (!dev_is_ide) {
1819                 scsi_scan_host(host);
1820         } else {
1821                 target = (device->dev_instance.b[5] << 8 |
1822                          device->dev_instance.b[4]);
1823                 ret = scsi_add_device(host, 0, target, 0);
1824                 if (ret) {
1825                         scsi_remove_host(host);
1826                         goto err_out2;
1827                 }
1828         }
1829         return 0;
1830
1831 err_out2:
1832         /*
1833          * Once we have connected with the host, we would need to
1834          * to invoke storvsc_dev_remove() to rollback this state and
1835          * this call also frees up the stor_device; hence the jump around
1836          * err_out1 label.
1837          */
1838         storvsc_dev_remove(device);
1839         goto err_out0;
1840
1841 err_out1:
1842         kfree(stor_device);
1843
1844 err_out0:
1845         scsi_host_put(host);
1846         return ret;
1847 }
1848
1849 static int storvsc_remove(struct hv_device *dev)
1850 {
1851         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1852         struct Scsi_Host *host = stor_device->host;
1853
1854         scsi_remove_host(host);
1855         storvsc_dev_remove(dev);
1856         scsi_host_put(host);
1857
1858         return 0;
1859 }
1860
1861 static struct hv_driver storvsc_drv = {
1862         .name = KBUILD_MODNAME,
1863         .id_table = id_table,
1864         .probe = storvsc_probe,
1865         .remove = storvsc_remove,
1866 };
1867
1868 static int __init storvsc_drv_init(void)
1869 {
1870         u32 max_outstanding_req_per_channel;
1871
1872         /*
1873          * Divide the ring buffer data size (which is 1 page less
1874          * than the ring buffer size since that page is reserved for
1875          * the ring buffer indices) by the max request size (which is
1876          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1877          */
1878         max_outstanding_req_per_channel =
1879                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1880                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1881                 sizeof(struct vstor_packet) + sizeof(u64) -
1882                 vmscsi_size_delta,
1883                 sizeof(u64)));
1884
1885         if (max_outstanding_req_per_channel <
1886             STORVSC_MAX_IO_REQUESTS)
1887                 return -EINVAL;
1888
1889         return vmbus_driver_register(&storvsc_drv);
1890 }
1891
1892 static void __exit storvsc_drv_exit(void)
1893 {
1894         vmbus_driver_unregister(&storvsc_drv);
1895 }
1896
1897 MODULE_LICENSE("GPL");
1898 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1899 module_init(storvsc_drv_init);
1900 module_exit(storvsc_drv_exit);