linux/drivers/scsi/storvsc_drv.c
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   1/*
   2 * Copyright (c) 2009, Microsoft Corporation.
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms and conditions of the GNU General Public License,
   6 * version 2, as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope it will be useful, but WITHOUT
   9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11 * more details.
  12 *
  13 * You should have received a copy of the GNU General Public License along with
  14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15 * Place - Suite 330, Boston, MA 02111-1307 USA.
  16 *
  17 * Authors:
  18 *   Haiyang Zhang <haiyangz@microsoft.com>
  19 *   Hank Janssen  <hjanssen@microsoft.com>
  20 *   K. Y. Srinivasan <kys@microsoft.com>
  21 */
  22
  23#include <linux/kernel.h>
  24#include <linux/wait.h>
  25#include <linux/sched.h>
  26#include <linux/completion.h>
  27#include <linux/string.h>
  28#include <linux/mm.h>
  29#include <linux/delay.h>
  30#include <linux/init.h>
  31#include <linux/slab.h>
  32#include <linux/module.h>
  33#include <linux/device.h>
  34#include <linux/hyperv.h>
  35#include <linux/mempool.h>
  36#include <scsi/scsi.h>
  37#include <scsi/scsi_cmnd.h>
  38#include <scsi/scsi_host.h>
  39#include <scsi/scsi_device.h>
  40#include <scsi/scsi_tcq.h>
  41#include <scsi/scsi_eh.h>
  42#include <scsi/scsi_devinfo.h>
  43#include <scsi/scsi_dbg.h>
  44
  45/*
  46 * All wire protocol details (storage protocol between the guest and the host)
  47 * are consolidated here.
  48 *
  49 * Begin protocol definitions.
  50 */
  51
  52/*
  53 * Version history:
  54 * V1 Beta: 0.1
  55 * V1 RC < 2008/1/31: 1.0
  56 * V1 RC > 2008/1/31:  2.0
  57 * Win7: 4.2
  58 */
  59
  60#define VMSTOR_CURRENT_MAJOR  4
  61#define VMSTOR_CURRENT_MINOR  2
  62
  63
  64/*  Packet structure describing virtual storage requests. */
  65enum vstor_packet_operation {
  66        VSTOR_OPERATION_COMPLETE_IO             = 1,
  67        VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  68        VSTOR_OPERATION_EXECUTE_SRB             = 3,
  69        VSTOR_OPERATION_RESET_LUN               = 4,
  70        VSTOR_OPERATION_RESET_ADAPTER           = 5,
  71        VSTOR_OPERATION_RESET_BUS               = 6,
  72        VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  73        VSTOR_OPERATION_END_INITIALIZATION      = 8,
  74        VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  75        VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  76        VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  77        VSTOR_OPERATION_MAXIMUM                 = 11
  78};
  79
  80/*
  81 * Platform neutral description of a scsi request -
  82 * this remains the same across the write regardless of 32/64 bit
  83 * note: it's patterned off the SCSI_PASS_THROUGH structure
  84 */
  85#define STORVSC_MAX_CMD_LEN                     0x10
  86#define STORVSC_SENSE_BUFFER_SIZE               0x12
  87#define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
  88
  89struct vmscsi_request {
  90        u16 length;
  91        u8 srb_status;
  92        u8 scsi_status;
  93
  94        u8  port_number;
  95        u8  path_id;
  96        u8  target_id;
  97        u8  lun;
  98
  99        u8  cdb_length;
 100        u8  sense_info_length;
 101        u8  data_in;
 102        u8  reserved;
 103
 104        u32 data_transfer_length;
 105
 106        union {
 107                u8 cdb[STORVSC_MAX_CMD_LEN];
 108                u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 109                u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 110        };
 111} __attribute((packed));
 112
 113
 114/*
 115 * This structure is sent during the intialization phase to get the different
 116 * properties of the channel.
 117 */
 118struct vmstorage_channel_properties {
 119        u16 protocol_version;
 120        u8  path_id;
 121        u8 target_id;
 122
 123        /* Note: port number is only really known on the client side */
 124        u32  port_number;
 125        u32  flags;
 126        u32   max_transfer_bytes;
 127
 128        /*
 129         * This id is unique for each channel and will correspond with
 130         * vendor specific data in the inquiry data.
 131         */
 132
 133        u64  unique_id;
 134} __packed;
 135
 136/*  This structure is sent during the storage protocol negotiations. */
 137struct vmstorage_protocol_version {
 138        /* Major (MSW) and minor (LSW) version numbers. */
 139        u16 major_minor;
 140
 141        /*
 142         * Revision number is auto-incremented whenever this file is changed
 143         * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 144         * definitely indicate incompatibility--but it does indicate mismatched
 145         * builds.
 146         * This is only used on the windows side. Just set it to 0.
 147         */
 148        u16 revision;
 149} __packed;
 150
 151/* Channel Property Flags */
 152#define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 153#define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 154
 155struct vstor_packet {
 156        /* Requested operation type */
 157        enum vstor_packet_operation operation;
 158
 159        /*  Flags - see below for values */
 160        u32 flags;
 161
 162        /* Status of the request returned from the server side. */
 163        u32 status;
 164
 165        /* Data payload area */
 166        union {
 167                /*
 168                 * Structure used to forward SCSI commands from the
 169                 * client to the server.
 170                 */
 171                struct vmscsi_request vm_srb;
 172
 173                /* Structure used to query channel properties. */
 174                struct vmstorage_channel_properties storage_channel_properties;
 175
 176                /* Used during version negotiations. */
 177                struct vmstorage_protocol_version version;
 178        };
 179} __packed;
 180
 181/*
 182 * Packet Flags:
 183 *
 184 * This flag indicates that the server should send back a completion for this
 185 * packet.
 186 */
 187
 188#define REQUEST_COMPLETION_FLAG 0x1
 189
 190/* Matches Windows-end */
 191enum storvsc_request_type {
 192        WRITE_TYPE = 0,
 193        READ_TYPE,
 194        UNKNOWN_TYPE,
 195};
 196
 197/*
 198 * SRB status codes and masks; a subset of the codes used here.
 199 */
 200
 201#define SRB_STATUS_AUTOSENSE_VALID      0x80
 202#define SRB_STATUS_INVALID_LUN  0x20
 203#define SRB_STATUS_SUCCESS      0x01
 204#define SRB_STATUS_ERROR        0x04
 205
 206/*
 207 * This is the end of Protocol specific defines.
 208 */
 209
 210
 211/*
 212 * We setup a mempool to allocate request structures for this driver
 213 * on a per-lun basis. The following define specifies the number of
 214 * elements in the pool.
 215 */
 216
 217#define STORVSC_MIN_BUF_NR                              64
 218static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
 219
 220module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 221MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 222
 223#define STORVSC_MAX_IO_REQUESTS                         128
 224
 225/*
 226 * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
 227 * reality, the path/target is not used (ie always set to 0) so our
 228 * scsi host adapter essentially has 1 bus with 1 target that contains
 229 * up to 256 luns.
 230 */
 231#define STORVSC_MAX_LUNS_PER_TARGET                     64
 232#define STORVSC_MAX_TARGETS                             1
 233#define STORVSC_MAX_CHANNELS                            1
 234
 235
 236
 237struct storvsc_cmd_request {
 238        struct list_head entry;
 239        struct scsi_cmnd *cmd;
 240
 241        unsigned int bounce_sgl_count;
 242        struct scatterlist *bounce_sgl;
 243
 244        struct hv_device *device;
 245
 246        /* Synchronize the request/response if needed */
 247        struct completion wait_event;
 248
 249        unsigned char *sense_buffer;
 250        struct hv_multipage_buffer data_buffer;
 251        struct vstor_packet vstor_packet;
 252};
 253
 254
 255/* A storvsc device is a device object that contains a vmbus channel */
 256struct storvsc_device {
 257        struct hv_device *device;
 258
 259        bool     destroy;
 260        bool     drain_notify;
 261        atomic_t num_outstanding_req;
 262        struct Scsi_Host *host;
 263
 264        wait_queue_head_t waiting_to_drain;
 265
 266        /*
 267         * Each unique Port/Path/Target represents 1 channel ie scsi
 268         * controller. In reality, the pathid, targetid is always 0
 269         * and the port is set by us
 270         */
 271        unsigned int port_number;
 272        unsigned char path_id;
 273        unsigned char target_id;
 274
 275        /* Used for vsc/vsp channel reset process */
 276        struct storvsc_cmd_request init_request;
 277        struct storvsc_cmd_request reset_request;
 278};
 279
 280struct stor_mem_pools {
 281        struct kmem_cache *request_pool;
 282        mempool_t *request_mempool;
 283};
 284
 285struct hv_host_device {
 286        struct hv_device *dev;
 287        unsigned int port;
 288        unsigned char path;
 289        unsigned char target;
 290};
 291
 292struct storvsc_scan_work {
 293        struct work_struct work;
 294        struct Scsi_Host *host;
 295        uint lun;
 296};
 297
 298static void storvsc_bus_scan(struct work_struct *work)
 299{
 300        struct storvsc_scan_work *wrk;
 301        int id, order_id;
 302
 303        wrk = container_of(work, struct storvsc_scan_work, work);
 304        for (id = 0; id < wrk->host->max_id; ++id) {
 305                if (wrk->host->reverse_ordering)
 306                        order_id = wrk->host->max_id - id - 1;
 307                else
 308                        order_id = id;
 309
 310                scsi_scan_target(&wrk->host->shost_gendev, 0,
 311                                order_id, SCAN_WILD_CARD, 1);
 312        }
 313        kfree(wrk);
 314}
 315
 316static void storvsc_remove_lun(struct work_struct *work)
 317{
 318        struct storvsc_scan_work *wrk;
 319        struct scsi_device *sdev;
 320
 321        wrk = container_of(work, struct storvsc_scan_work, work);
 322        if (!scsi_host_get(wrk->host))
 323                goto done;
 324
 325        sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 326
 327        if (sdev) {
 328                scsi_remove_device(sdev);
 329                scsi_device_put(sdev);
 330        }
 331        scsi_host_put(wrk->host);
 332
 333done:
 334        kfree(wrk);
 335}
 336
 337/*
 338 * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
 339 * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
 340 */
 341
 342static inline u16 storvsc_get_version(u8 major, u8 minor)
 343{
 344        u16 version;
 345
 346        version = ((major << 8) | minor);
 347        return version;
 348}
 349
 350/*
 351 * We can get incoming messages from the host that are not in response to
 352 * messages that we have sent out. An example of this would be messages
 353 * received by the guest to notify dynamic addition/removal of LUNs. To
 354 * deal with potential race conditions where the driver may be in the
 355 * midst of being unloaded when we might receive an unsolicited message
 356 * from the host, we have implemented a mechanism to gurantee sequential
 357 * consistency:
 358 *
 359 * 1) Once the device is marked as being destroyed, we will fail all
 360 *    outgoing messages.
 361 * 2) We permit incoming messages when the device is being destroyed,
 362 *    only to properly account for messages already sent out.
 363 */
 364
 365static inline struct storvsc_device *get_out_stor_device(
 366                                        struct hv_device *device)
 367{
 368        struct storvsc_device *stor_device;
 369
 370        stor_device = hv_get_drvdata(device);
 371
 372        if (stor_device && stor_device->destroy)
 373                stor_device = NULL;
 374
 375        return stor_device;
 376}
 377
 378
 379static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 380{
 381        dev->drain_notify = true;
 382        wait_event(dev->waiting_to_drain,
 383                   atomic_read(&dev->num_outstanding_req) == 0);
 384        dev->drain_notify = false;
 385}
 386
 387static inline struct storvsc_device *get_in_stor_device(
 388                                        struct hv_device *device)
 389{
 390        struct storvsc_device *stor_device;
 391
 392        stor_device = hv_get_drvdata(device);
 393
 394        if (!stor_device)
 395                goto get_in_err;
 396
 397        /*
 398         * If the device is being destroyed; allow incoming
 399         * traffic only to cleanup outstanding requests.
 400         */
 401
 402        if (stor_device->destroy  &&
 403                (atomic_read(&stor_device->num_outstanding_req) == 0))
 404                stor_device = NULL;
 405
 406get_in_err:
 407        return stor_device;
 408
 409}
 410
 411static void destroy_bounce_buffer(struct scatterlist *sgl,
 412                                  unsigned int sg_count)
 413{
 414        int i;
 415        struct page *page_buf;
 416
 417        for (i = 0; i < sg_count; i++) {
 418                page_buf = sg_page((&sgl[i]));
 419                if (page_buf != NULL)
 420                        __free_page(page_buf);
 421        }
 422
 423        kfree(sgl);
 424}
 425
 426static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 427{
 428        int i;
 429
 430        /* No need to check */
 431        if (sg_count < 2)
 432                return -1;
 433
 434        /* We have at least 2 sg entries */
 435        for (i = 0; i < sg_count; i++) {
 436                if (i == 0) {
 437                        /* make sure 1st one does not have hole */
 438                        if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 439                                return i;
 440                } else if (i == sg_count - 1) {
 441                        /* make sure last one does not have hole */
 442                        if (sgl[i].offset != 0)
 443                                return i;
 444                } else {
 445                        /* make sure no hole in the middle */
 446                        if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 447                                return i;
 448                }
 449        }
 450        return -1;
 451}
 452
 453static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 454                                                unsigned int sg_count,
 455                                                unsigned int len,
 456                                                int write)
 457{
 458        int i;
 459        int num_pages;
 460        struct scatterlist *bounce_sgl;
 461        struct page *page_buf;
 462        unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
 463
 464        num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 465
 466        bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 467        if (!bounce_sgl)
 468                return NULL;
 469
 470        sg_init_table(bounce_sgl, num_pages);
 471        for (i = 0; i < num_pages; i++) {
 472                page_buf = alloc_page(GFP_ATOMIC);
 473                if (!page_buf)
 474                        goto cleanup;
 475                sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
 476        }
 477
 478        return bounce_sgl;
 479
 480cleanup:
 481        destroy_bounce_buffer(bounce_sgl, num_pages);
 482        return NULL;
 483}
 484
 485/* Disgusting wrapper functions */
 486static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
 487{
 488        void *addr = kmap_atomic(sg_page(sgl + idx));
 489        return (unsigned long)addr;
 490}
 491
 492static inline void sg_kunmap_atomic(unsigned long addr)
 493{
 494        kunmap_atomic((void *)addr);
 495}
 496
 497
 498/* Assume the original sgl has enough room */
 499static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 500                                            struct scatterlist *bounce_sgl,
 501                                            unsigned int orig_sgl_count,
 502                                            unsigned int bounce_sgl_count)
 503{
 504        int i;
 505        int j = 0;
 506        unsigned long src, dest;
 507        unsigned int srclen, destlen, copylen;
 508        unsigned int total_copied = 0;
 509        unsigned long bounce_addr = 0;
 510        unsigned long dest_addr = 0;
 511        unsigned long flags;
 512
 513        local_irq_save(flags);
 514
 515        for (i = 0; i < orig_sgl_count; i++) {
 516                dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 517                dest = dest_addr;
 518                destlen = orig_sgl[i].length;
 519
 520                if (bounce_addr == 0)
 521                        bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 522
 523                while (destlen) {
 524                        src = bounce_addr + bounce_sgl[j].offset;
 525                        srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 526
 527                        copylen = min(srclen, destlen);
 528                        memcpy((void *)dest, (void *)src, copylen);
 529
 530                        total_copied += copylen;
 531                        bounce_sgl[j].offset += copylen;
 532                        destlen -= copylen;
 533                        dest += copylen;
 534
 535                        if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 536                                /* full */
 537                                sg_kunmap_atomic(bounce_addr);
 538                                j++;
 539
 540                                /*
 541                                 * It is possible that the number of elements
 542                                 * in the bounce buffer may not be equal to
 543                                 * the number of elements in the original
 544                                 * scatter list. Handle this correctly.
 545                                 */
 546
 547                                if (j == bounce_sgl_count) {
 548                                        /*
 549                                         * We are done; cleanup and return.
 550                                         */
 551                                        sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 552                                        local_irq_restore(flags);
 553                                        return total_copied;
 554                                }
 555
 556                                /* if we need to use another bounce buffer */
 557                                if (destlen || i != orig_sgl_count - 1)
 558                                        bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 559                        } else if (destlen == 0 && i == orig_sgl_count - 1) {
 560                                /* unmap the last bounce that is < PAGE_SIZE */
 561                                sg_kunmap_atomic(bounce_addr);
 562                        }
 563                }
 564
 565                sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
 566        }
 567
 568        local_irq_restore(flags);
 569
 570        return total_copied;
 571}
 572
 573/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 574static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 575                                          struct scatterlist *bounce_sgl,
 576                                          unsigned int orig_sgl_count)
 577{
 578        int i;
 579        int j = 0;
 580        unsigned long src, dest;
 581        unsigned int srclen, destlen, copylen;
 582        unsigned int total_copied = 0;
 583        unsigned long bounce_addr = 0;
 584        unsigned long src_addr = 0;
 585        unsigned long flags;
 586
 587        local_irq_save(flags);
 588
 589        for (i = 0; i < orig_sgl_count; i++) {
 590                src_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
 591                src = src_addr;
 592                srclen = orig_sgl[i].length;
 593
 594                if (bounce_addr == 0)
 595                        bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 596
 597                while (srclen) {
 598                        /* assume bounce offset always == 0 */
 599                        dest = bounce_addr + bounce_sgl[j].length;
 600                        destlen = PAGE_SIZE - bounce_sgl[j].length;
 601
 602                        copylen = min(srclen, destlen);
 603                        memcpy((void *)dest, (void *)src, copylen);
 604
 605                        total_copied += copylen;
 606                        bounce_sgl[j].length += copylen;
 607                        srclen -= copylen;
 608                        src += copylen;
 609
 610                        if (bounce_sgl[j].length == PAGE_SIZE) {
 611                                /* full..move to next entry */
 612                                sg_kunmap_atomic(bounce_addr);
 613                                j++;
 614
 615                                /* if we need to use another bounce buffer */
 616                                if (srclen || i != orig_sgl_count - 1)
 617                                        bounce_addr = sg_kmap_atomic(bounce_sgl,j);
 618
 619                        } else if (srclen == 0 && i == orig_sgl_count - 1) {
 620                                /* unmap the last bounce that is < PAGE_SIZE */
 621                                sg_kunmap_atomic(bounce_addr);
 622                        }
 623                }
 624
 625                sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
 626        }
 627
 628        local_irq_restore(flags);
 629
 630        return total_copied;
 631}
 632
 633static int storvsc_channel_init(struct hv_device *device)
 634{
 635        struct storvsc_device *stor_device;
 636        struct storvsc_cmd_request *request;
 637        struct vstor_packet *vstor_packet;
 638        int ret, t;
 639
 640        stor_device = get_out_stor_device(device);
 641        if (!stor_device)
 642                return -ENODEV;
 643
 644        request = &stor_device->init_request;
 645        vstor_packet = &request->vstor_packet;
 646
 647        /*
 648         * Now, initiate the vsc/vsp initialization protocol on the open
 649         * channel
 650         */
 651        memset(request, 0, sizeof(struct storvsc_cmd_request));
 652        init_completion(&request->wait_event);
 653        vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 654        vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 655
 656        ret = vmbus_sendpacket(device->channel, vstor_packet,
 657                               sizeof(struct vstor_packet),
 658                               (unsigned long)request,
 659                               VM_PKT_DATA_INBAND,
 660                               VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 661        if (ret != 0)
 662                goto cleanup;
 663
 664        t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 665        if (t == 0) {
 666                ret = -ETIMEDOUT;
 667                goto cleanup;
 668        }
 669
 670        if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 671            vstor_packet->status != 0)
 672                goto cleanup;
 673
 674
 675        /* reuse the packet for version range supported */
 676        memset(vstor_packet, 0, sizeof(struct vstor_packet));
 677        vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 678        vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 679
 680        vstor_packet->version.major_minor =
 681                storvsc_get_version(VMSTOR_CURRENT_MAJOR, VMSTOR_CURRENT_MINOR);
 682
 683        /*
 684         * The revision number is only used in Windows; set it to 0.
 685         */
 686        vstor_packet->version.revision = 0;
 687
 688        ret = vmbus_sendpacket(device->channel, vstor_packet,
 689                               sizeof(struct vstor_packet),
 690                               (unsigned long)request,
 691                               VM_PKT_DATA_INBAND,
 692                               VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 693        if (ret != 0)
 694                goto cleanup;
 695
 696        t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 697        if (t == 0) {
 698                ret = -ETIMEDOUT;
 699                goto cleanup;
 700        }
 701
 702        if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 703            vstor_packet->status != 0)
 704                goto cleanup;
 705
 706
 707        memset(vstor_packet, 0, sizeof(struct vstor_packet));
 708        vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 709        vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 710        vstor_packet->storage_channel_properties.port_number =
 711                                        stor_device->port_number;
 712
 713        ret = vmbus_sendpacket(device->channel, vstor_packet,
 714                               sizeof(struct vstor_packet),
 715                               (unsigned long)request,
 716                               VM_PKT_DATA_INBAND,
 717                               VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 718
 719        if (ret != 0)
 720                goto cleanup;
 721
 722        t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 723        if (t == 0) {
 724                ret = -ETIMEDOUT;
 725                goto cleanup;
 726        }
 727
 728        if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 729            vstor_packet->status != 0)
 730                goto cleanup;
 731
 732        stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
 733        stor_device->target_id
 734                = vstor_packet->storage_channel_properties.target_id;
 735
 736        memset(vstor_packet, 0, sizeof(struct vstor_packet));
 737        vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 738        vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 739
 740        ret = vmbus_sendpacket(device->channel, vstor_packet,
 741                               sizeof(struct vstor_packet),
 742                               (unsigned long)request,
 743                               VM_PKT_DATA_INBAND,
 744                               VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 745
 746        if (ret != 0)
 747                goto cleanup;
 748
 749        t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 750        if (t == 0) {
 751                ret = -ETIMEDOUT;
 752                goto cleanup;
 753        }
 754
 755        if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 756            vstor_packet->status != 0)
 757                goto cleanup;
 758
 759
 760cleanup:
 761        return ret;
 762}
 763
 764
 765static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
 766{
 767        struct scsi_cmnd *scmnd = cmd_request->cmd;
 768        struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
 769        void (*scsi_done_fn)(struct scsi_cmnd *);
 770        struct scsi_sense_hdr sense_hdr;
 771        struct vmscsi_request *vm_srb;
 772        struct storvsc_scan_work *wrk;
 773        struct stor_mem_pools *memp = scmnd->device->hostdata;
 774
 775        vm_srb = &cmd_request->vstor_packet.vm_srb;
 776        if (cmd_request->bounce_sgl_count) {
 777                if (vm_srb->data_in == READ_TYPE)
 778                        copy_from_bounce_buffer(scsi_sglist(scmnd),
 779                                        cmd_request->bounce_sgl,
 780                                        scsi_sg_count(scmnd),
 781                                        cmd_request->bounce_sgl_count);
 782                destroy_bounce_buffer(cmd_request->bounce_sgl,
 783                                        cmd_request->bounce_sgl_count);
 784        }
 785
 786        /*
 787         * If there is an error; offline the device since all
 788         * error recovery strategies would have already been
 789         * deployed on the host side. However, if the command
 790         * were a pass-through command deal with it appropriately.
 791         */
 792        scmnd->result = vm_srb->scsi_status;
 793
 794        if (vm_srb->srb_status == SRB_STATUS_ERROR) {
 795                switch (scmnd->cmnd[0]) {
 796                case ATA_16:
 797                case ATA_12:
 798                        set_host_byte(scmnd, DID_PASSTHROUGH);
 799                        break;
 800                default:
 801                        set_host_byte(scmnd, DID_TARGET_FAILURE);
 802                }
 803        }
 804
 805
 806        /*
 807         * If the LUN is invalid; remove the device.
 808         */
 809        if (vm_srb->srb_status == SRB_STATUS_INVALID_LUN) {
 810                struct storvsc_device *stor_dev;
 811                struct hv_device *dev = host_dev->dev;
 812                struct Scsi_Host *host;
 813
 814                stor_dev = get_in_stor_device(dev);
 815                host = stor_dev->host;
 816
 817                wrk = kmalloc(sizeof(struct storvsc_scan_work),
 818                                GFP_ATOMIC);
 819                if (!wrk) {
 820                        scmnd->result = DID_TARGET_FAILURE << 16;
 821                } else {
 822                        wrk->host = host;
 823                        wrk->lun = vm_srb->lun;
 824                        INIT_WORK(&wrk->work, storvsc_remove_lun);
 825                        schedule_work(&wrk->work);
 826                }
 827        }
 828
 829        if (scmnd->result) {
 830                if (scsi_normalize_sense(scmnd->sense_buffer,
 831                                SCSI_SENSE_BUFFERSIZE, &sense_hdr))
 832                        scsi_print_sense_hdr("storvsc", &sense_hdr);
 833        }
 834
 835        scsi_set_resid(scmnd,
 836                cmd_request->data_buffer.len -
 837                vm_srb->data_transfer_length);
 838
 839        scsi_done_fn = scmnd->scsi_done;
 840
 841        scmnd->host_scribble = NULL;
 842        scmnd->scsi_done = NULL;
 843
 844        scsi_done_fn(scmnd);
 845
 846        mempool_free(cmd_request, memp->request_mempool);
 847}
 848
 849static void storvsc_on_io_completion(struct hv_device *device,
 850                                  struct vstor_packet *vstor_packet,
 851                                  struct storvsc_cmd_request *request)
 852{
 853        struct storvsc_device *stor_device;
 854        struct vstor_packet *stor_pkt;
 855
 856        stor_device = hv_get_drvdata(device);
 857        stor_pkt = &request->vstor_packet;
 858
 859        /*
 860         * The current SCSI handling on the host side does
 861         * not correctly handle:
 862         * INQUIRY command with page code parameter set to 0x80
 863         * MODE_SENSE command with cmd[2] == 0x1c
 864         *
 865         * Setup srb and scsi status so this won't be fatal.
 866         * We do this so we can distinguish truly fatal failues
 867         * (srb status == 0x4) and off-line the device in that case.
 868         */
 869
 870        if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
 871           (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
 872                vstor_packet->vm_srb.scsi_status = 0;
 873                vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
 874        }
 875
 876
 877        /* Copy over the status...etc */
 878        stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 879        stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 880        stor_pkt->vm_srb.sense_info_length =
 881        vstor_packet->vm_srb.sense_info_length;
 882
 883        if (vstor_packet->vm_srb.scsi_status != 0 ||
 884                vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS){
 885                dev_warn(&device->device,
 886                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 887                         stor_pkt->vm_srb.cdb[0],
 888                         vstor_packet->vm_srb.scsi_status,
 889                         vstor_packet->vm_srb.srb_status);
 890        }
 891
 892        if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 893                /* CHECK_CONDITION */
 894                if (vstor_packet->vm_srb.srb_status &
 895                        SRB_STATUS_AUTOSENSE_VALID) {
 896                        /* autosense data available */
 897                        dev_warn(&device->device,
 898                                 "stor pkt %p autosense data valid - len %d\n",
 899                                 request,
 900                                 vstor_packet->vm_srb.sense_info_length);
 901
 902                        memcpy(request->sense_buffer,
 903                               vstor_packet->vm_srb.sense_data,
 904                               vstor_packet->vm_srb.sense_info_length);
 905
 906                }
 907        }
 908
 909        stor_pkt->vm_srb.data_transfer_length =
 910        vstor_packet->vm_srb.data_transfer_length;
 911
 912        storvsc_command_completion(request);
 913
 914        if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 915                stor_device->drain_notify)
 916                wake_up(&stor_device->waiting_to_drain);
 917
 918
 919}
 920
 921static void storvsc_on_receive(struct hv_device *device,
 922                             struct vstor_packet *vstor_packet,
 923                             struct storvsc_cmd_request *request)
 924{
 925        struct storvsc_scan_work *work;
 926        struct storvsc_device *stor_device;
 927
 928        switch (vstor_packet->operation) {
 929        case VSTOR_OPERATION_COMPLETE_IO:
 930                storvsc_on_io_completion(device, vstor_packet, request);
 931                break;
 932
 933        case VSTOR_OPERATION_REMOVE_DEVICE:
 934        case VSTOR_OPERATION_ENUMERATE_BUS:
 935                stor_device = get_in_stor_device(device);
 936                work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 937                if (!work)
 938                        return;
 939
 940                INIT_WORK(&work->work, storvsc_bus_scan);
 941                work->host = stor_device->host;
 942                schedule_work(&work->work);
 943                break;
 944
 945        default:
 946                break;
 947        }
 948}
 949
 950static void storvsc_on_channel_callback(void *context)
 951{
 952        struct hv_device *device = (struct hv_device *)context;
 953        struct storvsc_device *stor_device;
 954        u32 bytes_recvd;
 955        u64 request_id;
 956        unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 957        struct storvsc_cmd_request *request;
 958        int ret;
 959
 960
 961        stor_device = get_in_stor_device(device);
 962        if (!stor_device)
 963                return;
 964
 965        do {
 966                ret = vmbus_recvpacket(device->channel, packet,
 967                                       ALIGN(sizeof(struct vstor_packet), 8),
 968                                       &bytes_recvd, &request_id);
 969                if (ret == 0 && bytes_recvd > 0) {
 970
 971                        request = (struct storvsc_cmd_request *)
 972                                        (unsigned long)request_id;
 973
 974                        if ((request == &stor_device->init_request) ||
 975                            (request == &stor_device->reset_request)) {
 976
 977                                memcpy(&request->vstor_packet, packet,
 978                                       sizeof(struct vstor_packet));
 979                                complete(&request->wait_event);
 980                        } else {
 981                                storvsc_on_receive(device,
 982                                                (struct vstor_packet *)packet,
 983                                                request);
 984                        }
 985                } else {
 986                        break;
 987                }
 988        } while (1);
 989
 990        return;
 991}
 992
 993static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 994{
 995        struct vmstorage_channel_properties props;
 996        int ret;
 997
 998        memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 999
1000        ret = vmbus_open(device->channel,
1001                         ring_size,
1002                         ring_size,
1003                         (void *)&props,
1004                         sizeof(struct vmstorage_channel_properties),
1005                         storvsc_on_channel_callback, device);
1006
1007        if (ret != 0)
1008                return ret;
1009
1010        ret = storvsc_channel_init(device);
1011
1012        return ret;
1013}
1014
1015static int storvsc_dev_remove(struct hv_device *device)
1016{
1017        struct storvsc_device *stor_device;
1018        unsigned long flags;
1019
1020        stor_device = hv_get_drvdata(device);
1021
1022        spin_lock_irqsave(&device->channel->inbound_lock, flags);
1023        stor_device->destroy = true;
1024        spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1025
1026        /*
1027         * At this point, all outbound traffic should be disable. We
1028         * only allow inbound traffic (responses) to proceed so that
1029         * outstanding requests can be completed.
1030         */
1031
1032        storvsc_wait_to_drain(stor_device);
1033
1034        /*
1035         * Since we have already drained, we don't need to busy wait
1036         * as was done in final_release_stor_device()
1037         * Note that we cannot set the ext pointer to NULL until
1038         * we have drained - to drain the outgoing packets, we need to
1039         * allow incoming packets.
1040         */
1041        spin_lock_irqsave(&device->channel->inbound_lock, flags);
1042        hv_set_drvdata(device, NULL);
1043        spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1044
1045        /* Close the channel */
1046        vmbus_close(device->channel);
1047
1048        kfree(stor_device);
1049        return 0;
1050}
1051
1052static int storvsc_do_io(struct hv_device *device,
1053                              struct storvsc_cmd_request *request)
1054{
1055        struct storvsc_device *stor_device;
1056        struct vstor_packet *vstor_packet;
1057        int ret = 0;
1058
1059        vstor_packet = &request->vstor_packet;
1060        stor_device = get_out_stor_device(device);
1061
1062        if (!stor_device)
1063                return -ENODEV;
1064
1065
1066        request->device  = device;
1067
1068
1069        vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1070
1071        vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1072
1073
1074        vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1075
1076
1077        vstor_packet->vm_srb.data_transfer_length =
1078        request->data_buffer.len;
1079
1080        vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1081
1082        if (request->data_buffer.len) {
1083                ret = vmbus_sendpacket_multipagebuffer(device->channel,
1084                                &request->data_buffer,
1085                                vstor_packet,
1086                                sizeof(struct vstor_packet),
1087                                (unsigned long)request);
1088        } else {
1089                ret = vmbus_sendpacket(device->channel, vstor_packet,
1090                               sizeof(struct vstor_packet),
1091                               (unsigned long)request,
1092                               VM_PKT_DATA_INBAND,
1093                               VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1094        }
1095
1096        if (ret != 0)
1097                return ret;
1098
1099        atomic_inc(&stor_device->num_outstanding_req);
1100
1101        return ret;
1102}
1103
1104static int storvsc_device_alloc(struct scsi_device *sdevice)
1105{
1106        struct stor_mem_pools *memp;
1107        int number = STORVSC_MIN_BUF_NR;
1108
1109        memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
1110        if (!memp)
1111                return -ENOMEM;
1112
1113        memp->request_pool =
1114                kmem_cache_create(dev_name(&sdevice->sdev_dev),
1115                                sizeof(struct storvsc_cmd_request), 0,
1116                                SLAB_HWCACHE_ALIGN, NULL);
1117
1118        if (!memp->request_pool)
1119                goto err0;
1120
1121        memp->request_mempool = mempool_create(number, mempool_alloc_slab,
1122                                                mempool_free_slab,
1123                                                memp->request_pool);
1124
1125        if (!memp->request_mempool)
1126                goto err1;
1127
1128        sdevice->hostdata = memp;
1129
1130        return 0;
1131
1132err1:
1133        kmem_cache_destroy(memp->request_pool);
1134
1135err0:
1136        kfree(memp);
1137        return -ENOMEM;
1138}
1139
1140static void storvsc_device_destroy(struct scsi_device *sdevice)
1141{
1142        struct stor_mem_pools *memp = sdevice->hostdata;
1143
1144        mempool_destroy(memp->request_mempool);
1145        kmem_cache_destroy(memp->request_pool);
1146        kfree(memp);
1147        sdevice->hostdata = NULL;
1148}
1149
1150static int storvsc_device_configure(struct scsi_device *sdevice)
1151{
1152        scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
1153                                STORVSC_MAX_IO_REQUESTS);
1154
1155        blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1156
1157        blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1158
1159        return 0;
1160}
1161
1162static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1163                           sector_t capacity, int *info)
1164{
1165        sector_t nsect = capacity;
1166        sector_t cylinders = nsect;
1167        int heads, sectors_pt;
1168
1169        /*
1170         * We are making up these values; let us keep it simple.
1171         */
1172        heads = 0xff;
1173        sectors_pt = 0x3f;      /* Sectors per track */
1174        sector_div(cylinders, heads * sectors_pt);
1175        if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1176                cylinders = 0xffff;
1177
1178        info[0] = heads;
1179        info[1] = sectors_pt;
1180        info[2] = (int)cylinders;
1181
1182        return 0;
1183}
1184
1185static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1186{
1187        struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1188        struct hv_device *device = host_dev->dev;
1189
1190        struct storvsc_device *stor_device;
1191        struct storvsc_cmd_request *request;
1192        struct vstor_packet *vstor_packet;
1193        int ret, t;
1194
1195
1196        stor_device = get_out_stor_device(device);
1197        if (!stor_device)
1198                return FAILED;
1199
1200        request = &stor_device->reset_request;
1201        vstor_packet = &request->vstor_packet;
1202
1203        init_completion(&request->wait_event);
1204
1205        vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1206        vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1207        vstor_packet->vm_srb.path_id = stor_device->path_id;
1208
1209        ret = vmbus_sendpacket(device->channel, vstor_packet,
1210                               sizeof(struct vstor_packet),
1211                               (unsigned long)&stor_device->reset_request,
1212                               VM_PKT_DATA_INBAND,
1213                               VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1214        if (ret != 0)
1215                return FAILED;
1216
1217        t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1218        if (t == 0)
1219                return TIMEOUT_ERROR;
1220
1221
1222        /*
1223         * At this point, all outstanding requests in the adapter
1224         * should have been flushed out and return to us
1225         * There is a potential race here where the host may be in
1226         * the process of responding when we return from here.
1227         * Just wait for all in-transit packets to be accounted for
1228         * before we return from here.
1229         */
1230        storvsc_wait_to_drain(stor_device);
1231
1232        return SUCCESS;
1233}
1234
1235static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1236{
1237        bool allowed = true;
1238        u8 scsi_op = scmnd->cmnd[0];
1239
1240        switch (scsi_op) {
1241        /*
1242         * smartd sends this command and the host does not handle
1243         * this. So, don't send it.
1244         */
1245        case SET_WINDOW:
1246                scmnd->result = ILLEGAL_REQUEST << 16;
1247                allowed = false;
1248                break;
1249        default:
1250                break;
1251        }
1252        return allowed;
1253}
1254
1255static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1256{
1257        int ret;
1258        struct hv_host_device *host_dev = shost_priv(host);
1259        struct hv_device *dev = host_dev->dev;
1260        struct storvsc_cmd_request *cmd_request;
1261        unsigned int request_size = 0;
1262        int i;
1263        struct scatterlist *sgl;
1264        unsigned int sg_count = 0;
1265        struct vmscsi_request *vm_srb;
1266        struct stor_mem_pools *memp = scmnd->device->hostdata;
1267
1268        if (!storvsc_scsi_cmd_ok(scmnd)) {
1269                scmnd->scsi_done(scmnd);
1270                return 0;
1271        }
1272
1273        request_size = sizeof(struct storvsc_cmd_request);
1274
1275        cmd_request = mempool_alloc(memp->request_mempool,
1276                                       GFP_ATOMIC);
1277
1278        /*
1279         * We might be invoked in an interrupt context; hence
1280         * mempool_alloc() can fail.
1281         */
1282        if (!cmd_request)
1283                return SCSI_MLQUEUE_DEVICE_BUSY;
1284
1285        memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
1286
1287        /* Setup the cmd request */
1288        cmd_request->cmd = scmnd;
1289
1290        scmnd->host_scribble = (unsigned char *)cmd_request;
1291
1292        vm_srb = &cmd_request->vstor_packet.vm_srb;
1293
1294
1295        /* Build the SRB */
1296        switch (scmnd->sc_data_direction) {
1297        case DMA_TO_DEVICE:
1298                vm_srb->data_in = WRITE_TYPE;
1299                break;
1300        case DMA_FROM_DEVICE:
1301                vm_srb->data_in = READ_TYPE;
1302                break;
1303        default:
1304                vm_srb->data_in = UNKNOWN_TYPE;
1305                break;
1306        }
1307
1308
1309        vm_srb->port_number = host_dev->port;
1310        vm_srb->path_id = scmnd->device->channel;
1311        vm_srb->target_id = scmnd->device->id;
1312        vm_srb->lun = scmnd->device->lun;
1313
1314        vm_srb->cdb_length = scmnd->cmd_len;
1315
1316        memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1317
1318        cmd_request->sense_buffer = scmnd->sense_buffer;
1319
1320
1321        cmd_request->data_buffer.len = scsi_bufflen(scmnd);
1322        if (scsi_sg_count(scmnd)) {
1323                sgl = (struct scatterlist *)scsi_sglist(scmnd);
1324                sg_count = scsi_sg_count(scmnd);
1325
1326                /* check if we need to bounce the sgl */
1327                if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1328                        cmd_request->bounce_sgl =
1329                                create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1330                                                     scsi_bufflen(scmnd),
1331                                                     vm_srb->data_in);
1332                        if (!cmd_request->bounce_sgl) {
1333                                ret = SCSI_MLQUEUE_HOST_BUSY;
1334                                goto queue_error;
1335                        }
1336
1337                        cmd_request->bounce_sgl_count =
1338                                ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1339                                        PAGE_SHIFT;
1340
1341                        if (vm_srb->data_in == WRITE_TYPE)
1342                                copy_to_bounce_buffer(sgl,
1343                                        cmd_request->bounce_sgl,
1344                                        scsi_sg_count(scmnd));
1345
1346                        sgl = cmd_request->bounce_sgl;
1347                        sg_count = cmd_request->bounce_sgl_count;
1348                }
1349
1350                cmd_request->data_buffer.offset = sgl[0].offset;
1351
1352                for (i = 0; i < sg_count; i++)
1353                        cmd_request->data_buffer.pfn_array[i] =
1354                                page_to_pfn(sg_page((&sgl[i])));
1355
1356        } else if (scsi_sglist(scmnd)) {
1357                cmd_request->data_buffer.offset =
1358                        virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1359                cmd_request->data_buffer.pfn_array[0] =
1360                        virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1361        }
1362
1363        /* Invokes the vsc to start an IO */
1364        ret = storvsc_do_io(dev, cmd_request);
1365
1366        if (ret == -EAGAIN) {
1367                /* no more space */
1368
1369                if (cmd_request->bounce_sgl_count) {
1370                        destroy_bounce_buffer(cmd_request->bounce_sgl,
1371                                        cmd_request->bounce_sgl_count);
1372
1373                        ret = SCSI_MLQUEUE_DEVICE_BUSY;
1374                        goto queue_error;
1375                }
1376        }
1377
1378        return 0;
1379
1380queue_error:
1381        mempool_free(cmd_request, memp->request_mempool);
1382        scmnd->host_scribble = NULL;
1383        return ret;
1384}
1385
1386static struct scsi_host_template scsi_driver = {
1387        .module =               THIS_MODULE,
1388        .name =                 "storvsc_host_t",
1389        .bios_param =           storvsc_get_chs,
1390        .queuecommand =         storvsc_queuecommand,
1391        .eh_host_reset_handler =        storvsc_host_reset_handler,
1392        .slave_alloc =          storvsc_device_alloc,
1393        .slave_destroy =        storvsc_device_destroy,
1394        .slave_configure =      storvsc_device_configure,
1395        .cmd_per_lun =          1,
1396        /* 64 max_queue * 1 target */
1397        .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1398        .this_id =              -1,
1399        /* no use setting to 0 since ll_blk_rw reset it to 1 */
1400        /* currently 32 */
1401        .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
1402        .use_clustering =       DISABLE_CLUSTERING,
1403        /* Make sure we dont get a sg segment crosses a page boundary */
1404        .dma_boundary =         PAGE_SIZE-1,
1405};
1406
1407enum {
1408        SCSI_GUID,
1409        IDE_GUID,
1410};
1411
1412static const struct hv_vmbus_device_id id_table[] = {
1413        /* SCSI guid */
1414        { VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
1415                       0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
1416          .driver_data = SCSI_GUID },
1417        /* IDE guid */
1418        { VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
1419                       0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
1420          .driver_data = IDE_GUID },
1421        { },
1422};
1423
1424MODULE_DEVICE_TABLE(vmbus, id_table);
1425
1426static int storvsc_probe(struct hv_device *device,
1427                        const struct hv_vmbus_device_id *dev_id)
1428{
1429        int ret;
1430        struct Scsi_Host *host;
1431        struct hv_host_device *host_dev;
1432        bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1433        int target = 0;
1434        struct storvsc_device *stor_device;
1435
1436        host = scsi_host_alloc(&scsi_driver,
1437                               sizeof(struct hv_host_device));
1438        if (!host)
1439                return -ENOMEM;
1440
1441        host_dev = shost_priv(host);
1442        memset(host_dev, 0, sizeof(struct hv_host_device));
1443
1444        host_dev->port = host->host_no;
1445        host_dev->dev = device;
1446
1447
1448        stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1449        if (!stor_device) {
1450                ret = -ENOMEM;
1451                goto err_out0;
1452        }
1453
1454        stor_device->destroy = false;
1455        init_waitqueue_head(&stor_device->waiting_to_drain);
1456        stor_device->device = device;
1457        stor_device->host = host;
1458        hv_set_drvdata(device, stor_device);
1459
1460        stor_device->port_number = host->host_no;
1461        ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1462        if (ret)
1463                goto err_out1;
1464
1465        host_dev->path = stor_device->path_id;
1466        host_dev->target = stor_device->target_id;
1467
1468        /* max # of devices per target */
1469        host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1470        /* max # of targets per channel */
1471        host->max_id = STORVSC_MAX_TARGETS;
1472        /* max # of channels */
1473        host->max_channel = STORVSC_MAX_CHANNELS - 1;
1474        /* max cmd length */
1475        host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1476
1477        /* Register the HBA and start the scsi bus scan */
1478        ret = scsi_add_host(host, &device->device);
1479        if (ret != 0)
1480                goto err_out2;
1481
1482        if (!dev_is_ide) {
1483                scsi_scan_host(host);
1484        } else {
1485                target = (device->dev_instance.b[5] << 8 |
1486                         device->dev_instance.b[4]);
1487                ret = scsi_add_device(host, 0, target, 0);
1488                if (ret) {
1489                        scsi_remove_host(host);
1490                        goto err_out2;
1491                }
1492        }
1493        return 0;
1494
1495err_out2:
1496        /*
1497         * Once we have connected with the host, we would need to
1498         * to invoke storvsc_dev_remove() to rollback this state and
1499         * this call also frees up the stor_device; hence the jump around
1500         * err_out1 label.
1501         */
1502        storvsc_dev_remove(device);
1503        goto err_out0;
1504
1505err_out1:
1506        kfree(stor_device);
1507
1508err_out0:
1509        scsi_host_put(host);
1510        return ret;
1511}
1512
1513static int storvsc_remove(struct hv_device *dev)
1514{
1515        struct storvsc_device *stor_device = hv_get_drvdata(dev);
1516        struct Scsi_Host *host = stor_device->host;
1517
1518        scsi_remove_host(host);
1519        storvsc_dev_remove(dev);
1520        scsi_host_put(host);
1521
1522        return 0;
1523}
1524
1525static struct hv_driver storvsc_drv = {
1526        .name = KBUILD_MODNAME,
1527        .id_table = id_table,
1528        .probe = storvsc_probe,
1529        .remove = storvsc_remove,
1530};
1531
1532static int __init storvsc_drv_init(void)
1533{
1534        u32 max_outstanding_req_per_channel;
1535
1536        /*
1537         * Divide the ring buffer data size (which is 1 page less
1538         * than the ring buffer size since that page is reserved for
1539         * the ring buffer indices) by the max request size (which is
1540         * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1541         */
1542        max_outstanding_req_per_channel =
1543                ((storvsc_ringbuffer_size - PAGE_SIZE) /
1544                ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1545                sizeof(struct vstor_packet) + sizeof(u64),
1546                sizeof(u64)));
1547
1548        if (max_outstanding_req_per_channel <
1549            STORVSC_MAX_IO_REQUESTS)
1550                return -EINVAL;
1551
1552        return vmbus_driver_register(&storvsc_drv);
1553}
1554
1555static void __exit storvsc_drv_exit(void)
1556{
1557        vmbus_driver_unregister(&storvsc_drv);
1558}
1559
1560MODULE_LICENSE("GPL");
1561MODULE_VERSION(HV_DRV_VERSION);
1562MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1563module_init(storvsc_drv_init);
1564module_exit(storvsc_drv_exit);
1565
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