drivers/scsi/storvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *   K. Y. Srinivasan <kys@microsoft.com>
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/wait.h>
  25 #include <linux/sched.h>
  26 #include <linux/completion.h>
  27 #include <linux/string.h>
  28 #include <linux/mm.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/device.h>
  34 #include <linux/hyperv.h>
  35 #include <linux/blkdev.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_tcq.h>
  41 #include <scsi/scsi_eh.h>
  42 #include <scsi/scsi_devinfo.h>
  43 #include <scsi/scsi_dbg.h>
  44 #include <scsi/scsi_transport_fc.h>
  45 #include <scsi/scsi_transport.h>
  46
  47 /*
  48  * All wire protocol details (storage protocol between the guest and the host)
  49  * are consolidated here.
  50  *
  51  * Begin protocol definitions.
  52  */
  53
  54 /*
  55  * Version history:
  56  * V1 Beta: 0.1
  57  * V1 RC < 2008/1/31: 1.0
  58  * V1 RC > 2008/1/31:  2.0
  59  * Win7: 4.2
  60  * Win8: 5.1
  61  * Win8.1: 6.0
  62  * Win10: 6.2
  63  */
  64
  65 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  66                                                 (((MINOR_) & 0xff)))
  67
  68 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  69 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  70 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  71 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  72 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  73
  74 /*  Packet structure describing virtual storage requests. */
  75 enum vstor_packet_operation {
  76         VSTOR_OPERATION_COMPLETE_IO             = 1,
  77         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  78         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  79         VSTOR_OPERATION_RESET_LUN               = 4,
  80         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  81         VSTOR_OPERATION_RESET_BUS               = 6,
  82         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  83         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  84         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  85         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  86         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  87         VSTOR_OPERATION_FCHBA_DATA              = 12,
  88         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  89         VSTOR_OPERATION_MAXIMUM                 = 13
  90 };
  91
  92 /*
  93  * WWN packet for Fibre Channel HBA
  94  */
  95
  96 struct hv_fc_wwn_packet {
  97         u8      primary_active;
  98         u8      reserved1[3];
  99         u8      primary_port_wwn[8];
 100         u8      primary_node_wwn[8];
 101         u8      secondary_port_wwn[8];
 102         u8      secondary_node_wwn[8];
 103 };
 104
 105
 106
 107 /*
 108  * SRB Flag Bits
 109  */
 110
 111 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 112 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 113 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 114 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 115 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 116 #define SRB_FLAGS_DATA_IN                       0x00000040
 117 #define SRB_FLAGS_DATA_OUT                      0x00000080
 118 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 119 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 120 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 121 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 122 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 123
 124 /*
 125  * This flag indicates the request is part of the workflow for processing a D3.
 126  */
 127 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 128 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 129 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 130 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 131 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 132 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 133 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 134 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 135 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 136 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 137 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 138
 139
 140 /*
 141  * Platform neutral description of a scsi request -
 142  * this remains the same across the write regardless of 32/64 bit
 143  * note: it's patterned off the SCSI_PASS_THROUGH structure
 144  */
 145 #define STORVSC_MAX_CMD_LEN                     0x10
 146
 147 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 148 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 149
 150 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 151 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 152
 153 /*
 154  * Sense buffer size changed in win8; have a run-time
 155  * variable to track the size we should use.  This value will
 156  * likely change during protocol negotiation but it is valid
 157  * to start by assuming pre-Win8.
 158  */
 159 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 160
 161 /*
 162  * The storage protocol version is determined during the
 163  * initial exchange with the host.  It will indicate which
 164  * storage functionality is available in the host.
 165 */
 166 static int vmstor_proto_version;
 167
 168 #define STORVSC_LOGGING_NONE    0
 169 #define STORVSC_LOGGING_ERROR   1
 170 #define STORVSC_LOGGING_WARN    2
 171
 172 static int logging_level = STORVSC_LOGGING_ERROR;
 173 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 174 MODULE_PARM_DESC(logging_level,
 175         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 176
 177 static inline bool do_logging(int level)
 178 {
 179         return logging_level >= level;
 180 }
 181
 182 #define storvsc_log(dev, level, fmt, ...)                       \
 183 do {                                                            \
 184         if (do_logging(level))                                  \
 185                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 186 } while (0)
 187
 188 struct vmscsi_win8_extension {
 189         /*
 190          * The following were added in Windows 8
 191          */
 192         u16 reserve;
 193         u8  queue_tag;
 194         u8  queue_action;
 195         u32 srb_flags;
 196         u32 time_out_value;
 197         u32 queue_sort_ey;
 198 } __packed;
 199
 200 struct vmscsi_request {
 201         u16 length;
 202         u8 srb_status;
 203         u8 scsi_status;
 204
 205         u8  port_number;
 206         u8  path_id;
 207         u8  target_id;
 208         u8  lun;
 209
 210         u8  cdb_length;
 211         u8  sense_info_length;
 212         u8  data_in;
 213         u8  reserved;
 214
 215         u32 data_transfer_length;
 216
 217         union {
 218                 u8 cdb[STORVSC_MAX_CMD_LEN];
 219                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 220                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 221         };
 222         /*
 223          * The following was added in win8.
 224          */
 225         struct vmscsi_win8_extension win8_extension;
 226
 227 } __attribute((packed));
 228
 229
 230 /*
 231  * The size of the vmscsi_request has changed in win8. The
 232  * additional size is because of new elements added to the
 233  * structure. These elements are valid only when we are talking
 234  * to a win8 host.
 235  * Track the correction to size we need to apply. This value
 236  * will likely change during protocol negotiation but it is
 237  * valid to start by assuming pre-Win8.
 238  */
 239 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 240
 241 /*
 242  * The list of storage protocols in order of preference.
 243  */
 244 struct vmstor_protocol {
 245         int protocol_version;
 246         int sense_buffer_size;
 247         int vmscsi_size_delta;
 248 };
 249
 250
 251 static const struct vmstor_protocol vmstor_protocols[] = {
 252         {
 253                 VMSTOR_PROTO_VERSION_WIN10,
 254                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 255                 0
 256         },
 257         {
 258                 VMSTOR_PROTO_VERSION_WIN8_1,
 259                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 260                 0
 261         },
 262         {
 263                 VMSTOR_PROTO_VERSION_WIN8,
 264                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 265                 0
 266         },
 267         {
 268                 VMSTOR_PROTO_VERSION_WIN7,
 269                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 270                 sizeof(struct vmscsi_win8_extension),
 271         },
 272         {
 273                 VMSTOR_PROTO_VERSION_WIN6,
 274                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 275                 sizeof(struct vmscsi_win8_extension),
 276         }
 277 };
 278
 279
 280 /*
 281  * This structure is sent during the intialization phase to get the different
 282  * properties of the channel.
 283  */
 284
 285 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 286
 287 struct vmstorage_channel_properties {
 288         u32 reserved;
 289         u16 max_channel_cnt;
 290         u16 reserved1;
 291
 292         u32 flags;
 293         u32   max_transfer_bytes;
 294
 295         u64  reserved2;
 296 } __packed;
 297
 298 /*  This structure is sent during the storage protocol negotiations. */
 299 struct vmstorage_protocol_version {
 300         /* Major (MSW) and minor (LSW) version numbers. */
 301         u16 major_minor;
 302
 303         /*
 304          * Revision number is auto-incremented whenever this file is changed
 305          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 306          * definitely indicate incompatibility--but it does indicate mismatched
 307          * builds.
 308          * This is only used on the windows side. Just set it to 0.
 309          */
 310         u16 revision;
 311 } __packed;
 312
 313 /* Channel Property Flags */
 314 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 315 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 316
 317 struct vstor_packet {
 318         /* Requested operation type */
 319         enum vstor_packet_operation operation;
 320
 321         /*  Flags - see below for values */
 322         u32 flags;
 323
 324         /* Status of the request returned from the server side. */
 325         u32 status;
 326
 327         /* Data payload area */
 328         union {
 329                 /*
 330                  * Structure used to forward SCSI commands from the
 331                  * client to the server.
 332                  */
 333                 struct vmscsi_request vm_srb;
 334
 335                 /* Structure used to query channel properties. */
 336                 struct vmstorage_channel_properties storage_channel_properties;
 337
 338                 /* Used during version negotiations. */
 339                 struct vmstorage_protocol_version version;
 340
 341                 /* Fibre channel address packet */
 342                 struct hv_fc_wwn_packet wwn_packet;
 343
 344                 /* Number of sub-channels to create */
 345                 u16 sub_channel_count;
 346
 347                 /* This will be the maximum of the union members */
 348                 u8  buffer[0x34];
 349         };
 350 } __packed;
 351
 352 /*
 353  * Packet Flags:
 354  *
 355  * This flag indicates that the server should send back a completion for this
 356  * packet.
 357  */
 358
 359 #define REQUEST_COMPLETION_FLAG 0x1
 360
 361 /* Matches Windows-end */
 362 enum storvsc_request_type {
 363         WRITE_TYPE = 0,
 364         READ_TYPE,
 365         UNKNOWN_TYPE,
 366 };
 367
 368 /*
 369  * SRB status codes and masks; a subset of the codes used here.
 370  */
 371
 372 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 373 #define SRB_STATUS_QUEUE_FROZEN         0x40
 374 #define SRB_STATUS_INVALID_LUN  0x20
 375 #define SRB_STATUS_SUCCESS      0x01
 376 #define SRB_STATUS_ABORTED      0x02
 377 #define SRB_STATUS_ERROR        0x04
 378
 379 #define SRB_STATUS(status) \
 380         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 381 /*
 382  * This is the end of Protocol specific defines.
 383  */
 384
 385 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 386 static u32 max_outstanding_req_per_channel;
 387
 388 static int storvsc_vcpus_per_sub_channel = 4;
 389
 390 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 391 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 392
 393 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 394 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 395 /*
 396  * Timeout in seconds for all devices managed by this driver.
 397  */
 398 static int storvsc_timeout = 180;
 399
 400 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
 401
 402 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 403 static struct scsi_transport_template *fc_transport_template;
 404 #endif
 405
 406 static void storvsc_on_channel_callback(void *context);
 407
 408 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 409 #define STORVSC_MAX_TARGETS                             2
 410 #define STORVSC_MAX_CHANNELS                            8
 411
 412 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 413 #define STORVSC_FC_MAX_TARGETS                          128
 414 #define STORVSC_FC_MAX_CHANNELS                         8
 415
 416 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 417 #define STORVSC_IDE_MAX_TARGETS                         1
 418 #define STORVSC_IDE_MAX_CHANNELS                        1
 419
 420 struct storvsc_cmd_request {
 421         struct scsi_cmnd *cmd;
 422
 423         struct hv_device *device;
 424
 425         /* Synchronize the request/response if needed */
 426         struct completion wait_event;
 427
 428         struct vmbus_channel_packet_multipage_buffer mpb;
 429         struct vmbus_packet_mpb_array *payload;
 430         u32 payload_sz;
 431
 432         struct vstor_packet vstor_packet;
 433 };
 434
 435
 436 /* A storvsc device is a device object that contains a vmbus channel */
 437 struct storvsc_device {
 438         struct hv_device *device;
 439
 440         bool     destroy;
 441         bool     drain_notify;
 442         bool     open_sub_channel;
 443         atomic_t num_outstanding_req;
 444         struct Scsi_Host *host;
 445
 446         wait_queue_head_t waiting_to_drain;
 447
 448         /*
 449          * Each unique Port/Path/Target represents 1 channel ie scsi
 450          * controller. In reality, the pathid, targetid is always 0
 451          * and the port is set by us
 452          */
 453         unsigned int port_number;
 454         unsigned char path_id;
 455         unsigned char target_id;
 456
 457         /*
 458          * Max I/O, the device can support.
 459          */
 460         u32   max_transfer_bytes;
 461         /* Used for vsc/vsp channel reset process */
 462         struct storvsc_cmd_request init_request;
 463         struct storvsc_cmd_request reset_request;
 464         /*
 465          * Currently active port and node names for FC devices.
 466          */
 467         u64 node_name;
 468         u64 port_name;
 469 };
 470
 471 struct hv_host_device {
 472         struct hv_device *dev;
 473         unsigned int port;
 474         unsigned char path;
 475         unsigned char target;
 476 };
 477
 478 struct storvsc_scan_work {
 479         struct work_struct work;
 480         struct Scsi_Host *host;
 481         u8 lun;
 482         u8 tgt_id;
 483 };
 484
 485 static void storvsc_device_scan(struct work_struct *work)
 486 {
 487         struct storvsc_scan_work *wrk;
 488         struct scsi_device *sdev;
 489
 490         wrk = container_of(work, struct storvsc_scan_work, work);
 491
 492         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 493         if (!sdev)
 494                 goto done;
 495         scsi_rescan_device(&sdev->sdev_gendev);
 496         scsi_device_put(sdev);
 497
 498 done:
 499         kfree(wrk);
 500 }
 501
 502 static void storvsc_host_scan(struct work_struct *work)
 503 {
 504         struct storvsc_scan_work *wrk;
 505         struct Scsi_Host *host;
 506         struct scsi_device *sdev;
 507
 508         wrk = container_of(work, struct storvsc_scan_work, work);
 509         host = wrk->host;
 510
 511         /*
 512          * Before scanning the host, first check to see if any of the
 513          * currrently known devices have been hot removed. We issue a
 514          * "unit ready" command against all currently known devices.
 515          * This I/O will result in an error for devices that have been
 516          * removed. As part of handling the I/O error, we remove the device.
 517          *
 518          * When a LUN is added or removed, the host sends us a signal to
 519          * scan the host. Thus we are forced to discover the LUNs that
 520          * may have been removed this way.
 521          */
 522         mutex_lock(&host->scan_mutex);
 523         shost_for_each_device(sdev, host)
 524                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 525         mutex_unlock(&host->scan_mutex);
 526         /*
 527          * Now scan the host to discover LUNs that may have been added.
 528          */
 529         scsi_scan_host(host);
 530
 531         kfree(wrk);
 532 }
 533
 534 static void storvsc_remove_lun(struct work_struct *work)
 535 {
 536         struct storvsc_scan_work *wrk;
 537         struct scsi_device *sdev;
 538
 539         wrk = container_of(work, struct storvsc_scan_work, work);
 540         if (!scsi_host_get(wrk->host))
 541                 goto done;
 542
 543         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 544
 545         if (sdev) {
 546                 scsi_remove_device(sdev);
 547                 scsi_device_put(sdev);
 548         }
 549         scsi_host_put(wrk->host);
 550
 551 done:
 552         kfree(wrk);
 553 }
 554
 555
 556 /*
 557  * We can get incoming messages from the host that are not in response to
 558  * messages that we have sent out. An example of this would be messages
 559  * received by the guest to notify dynamic addition/removal of LUNs. To
 560  * deal with potential race conditions where the driver may be in the
 561  * midst of being unloaded when we might receive an unsolicited message
 562  * from the host, we have implemented a mechanism to gurantee sequential
 563  * consistency:
 564  *
 565  * 1) Once the device is marked as being destroyed, we will fail all
 566  *    outgoing messages.
 567  * 2) We permit incoming messages when the device is being destroyed,
 568  *    only to properly account for messages already sent out.
 569  */
 570
 571 static inline struct storvsc_device *get_out_stor_device(
 572                                         struct hv_device *device)
 573 {
 574         struct storvsc_device *stor_device;
 575
 576         stor_device = hv_get_drvdata(device);
 577
 578         if (stor_device && stor_device->destroy)
 579                 stor_device = NULL;
 580
 581         return stor_device;
 582 }
 583
 584
 585 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 586 {
 587         dev->drain_notify = true;
 588         wait_event(dev->waiting_to_drain,
 589                    atomic_read(&dev->num_outstanding_req) == 0);
 590         dev->drain_notify = false;
 591 }
 592
 593 static inline struct storvsc_device *get_in_stor_device(
 594                                         struct hv_device *device)
 595 {
 596         struct storvsc_device *stor_device;
 597
 598         stor_device = hv_get_drvdata(device);
 599
 600         if (!stor_device)
 601                 goto get_in_err;
 602
 603         /*
 604          * If the device is being destroyed; allow incoming
 605          * traffic only to cleanup outstanding requests.
 606          */
 607
 608         if (stor_device->destroy  &&
 609                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 610                 stor_device = NULL;
 611
 612 get_in_err:
 613         return stor_device;
 614
 615 }
 616
 617 static void handle_sc_creation(struct vmbus_channel *new_sc)
 618 {
 619         struct hv_device *device = new_sc->primary_channel->device_obj;
 620         struct storvsc_device *stor_device;
 621         struct vmstorage_channel_properties props;
 622
 623         stor_device = get_out_stor_device(device);
 624         if (!stor_device)
 625                 return;
 626
 627         if (stor_device->open_sub_channel == false)
 628                 return;
 629
 630         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 631
 632         vmbus_open(new_sc,
 633                    storvsc_ringbuffer_size,
 634                    storvsc_ringbuffer_size,
 635                    (void *)&props,
 636                    sizeof(struct vmstorage_channel_properties),
 637                    storvsc_on_channel_callback, new_sc);
 638 }
 639
 640 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 641 {
 642         struct storvsc_device *stor_device;
 643         int num_cpus = num_online_cpus();
 644         int num_sc;
 645         struct storvsc_cmd_request *request;
 646         struct vstor_packet *vstor_packet;
 647         int ret, t;
 648
 649         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 650         stor_device = get_out_stor_device(device);
 651         if (!stor_device)
 652                 return;
 653
 654         request = &stor_device->init_request;
 655         vstor_packet = &request->vstor_packet;
 656
 657         stor_device->open_sub_channel = true;
 658         /*
 659          * Establish a handler for dealing with subchannels.
 660          */
 661         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 662
 663         /*
 664          * Check to see if sub-channels have already been created. This
 665          * can happen when this driver is re-loaded after unloading.
 666          */
 667
 668         if (vmbus_are_subchannels_present(device->channel))
 669                 return;
 670
 671         stor_device->open_sub_channel = false;
 672         /*
 673          * Request the host to create sub-channels.
 674          */
 675         memset(request, 0, sizeof(struct storvsc_cmd_request));
 676         init_completion(&request->wait_event);
 677         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 678         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 679         vstor_packet->sub_channel_count = num_sc;
 680
 681         ret = vmbus_sendpacket(device->channel, vstor_packet,
 682                                (sizeof(struct vstor_packet) -
 683                                vmscsi_size_delta),
 684                                (unsigned long)request,
 685                                VM_PKT_DATA_INBAND,
 686                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 687
 688         if (ret != 0)
 689                 return;
 690
 691         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 692         if (t == 0)
 693                 return;
 694
 695         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 696             vstor_packet->status != 0)
 697                 return;
 698
 699         /*
 700          * Now that we created the sub-channels, invoke the check; this
 701          * may trigger the callback.
 702          */
 703         stor_device->open_sub_channel = true;
 704         vmbus_are_subchannels_present(device->channel);
 705 }
 706
 707 static void cache_wwn(struct storvsc_device *stor_device,
 708                       struct vstor_packet *vstor_packet)
 709 {
 710         /*
 711          * Cache the currently active port and node ww names.
 712          */
 713         if (vstor_packet->wwn_packet.primary_active) {
 714                 stor_device->node_name =
 715                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 716                 stor_device->port_name =
 717                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 718         } else {
 719                 stor_device->node_name =
 720                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 721                 stor_device->port_name =
 722                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 723         }
 724 }
 725
 726
 727 static int storvsc_execute_vstor_op(struct hv_device *device,
 728                                     struct storvsc_cmd_request *request,
 729                                     bool status_check)
 730 {
 731         struct vstor_packet *vstor_packet;
 732         int ret, t;
 733
 734         vstor_packet = &request->vstor_packet;
 735
 736         init_completion(&request->wait_event);
 737         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 738
 739         ret = vmbus_sendpacket(device->channel, vstor_packet,
 740                                (sizeof(struct vstor_packet) -
 741                                vmscsi_size_delta),
 742                                (unsigned long)request,
 743                                VM_PKT_DATA_INBAND,
 744                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 745         if (ret != 0)
 746                 return ret;
 747
 748         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 749         if (t == 0)
 750                 return -ETIMEDOUT;
 751
 752         if (!status_check)
 753                 return ret;
 754
 755         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 756             vstor_packet->status != 0)
 757                 return -EINVAL;
 758
 759         return ret;
 760 }
 761
 762 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 763 {
 764         struct storvsc_device *stor_device;
 765         struct storvsc_cmd_request *request;
 766         struct vstor_packet *vstor_packet;
 767         int ret, i;
 768         int max_chns;
 769         bool process_sub_channels = false;
 770
 771         stor_device = get_out_stor_device(device);
 772         if (!stor_device)
 773                 return -ENODEV;
 774
 775         request = &stor_device->init_request;
 776         vstor_packet = &request->vstor_packet;
 777
 778         /*
 779          * Now, initiate the vsc/vsp initialization protocol on the open
 780          * channel
 781          */
 782         memset(request, 0, sizeof(struct storvsc_cmd_request));
 783         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 784         ret = storvsc_execute_vstor_op(device, request, true);
 785         if (ret)
 786                 return ret;
 787         /*
 788          * Query host supported protocol version.
 789          */
 790
 791         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 792                 /* reuse the packet for version range supported */
 793                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 794                 vstor_packet->operation =
 795                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 796
 797                 vstor_packet->version.major_minor =
 798                         vmstor_protocols[i].protocol_version;
 799
 800                 /*
 801                  * The revision number is only used in Windows; set it to 0.
 802                  */
 803                 vstor_packet->version.revision = 0;
 804                 ret = storvsc_execute_vstor_op(device, request, false);
 805                 if (ret != 0)
 806                         return ret;
 807
 808                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 809                         return -EINVAL;
 810
 811                 if (vstor_packet->status == 0) {
 812                         vmstor_proto_version =
 813                                 vmstor_protocols[i].protocol_version;
 814
 815                         sense_buffer_size =
 816                                 vmstor_protocols[i].sense_buffer_size;
 817
 818                         vmscsi_size_delta =
 819                                 vmstor_protocols[i].vmscsi_size_delta;
 820
 821                         break;
 822                 }
 823         }
 824
 825         if (vstor_packet->status != 0)
 826                 return -EINVAL;
 827
 828
 829         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 830         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 831         ret = storvsc_execute_vstor_op(device, request, true);
 832         if (ret != 0)
 833                 return ret;
 834
 835         /*
 836          * Check to see if multi-channel support is there.
 837          * Hosts that implement protocol version of 5.1 and above
 838          * support multi-channel.
 839          */
 840         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 841         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 842                 if (vstor_packet->storage_channel_properties.flags &
 843                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 844                         process_sub_channels = true;
 845         }
 846         stor_device->max_transfer_bytes =
 847                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 848
 849         if (!is_fc)
 850                 goto done;
 851
 852         /*
 853          * For FC devices retrieve FC HBA data.
 854          */
 855         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 856         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 857         ret = storvsc_execute_vstor_op(device, request, true);
 858         if (ret != 0)
 859                 return ret;
 860
 861         /*
 862          * Cache the currently active port and node ww names.
 863          */
 864         cache_wwn(stor_device, vstor_packet);
 865
 866 done:
 867
 868         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 869         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 870         ret = storvsc_execute_vstor_op(device, request, true);
 871         if (ret != 0)
 872                 return ret;
 873
 874         if (process_sub_channels)
 875                 handle_multichannel_storage(device, max_chns);
 876
 877         return ret;
 878 }
 879
 880 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 881                                 struct scsi_cmnd *scmnd,
 882                                 struct Scsi_Host *host,
 883                                 u8 asc, u8 ascq)
 884 {
 885         struct storvsc_scan_work *wrk;
 886         void (*process_err_fn)(struct work_struct *work);
 887         bool do_work = false;
 888
 889         switch (SRB_STATUS(vm_srb->srb_status)) {
 890         case SRB_STATUS_ERROR:
 891                 /*
 892                  * If there is an error; offline the device since all
 893                  * error recovery strategies would have already been
 894                  * deployed on the host side. However, if the command
 895                  * were a pass-through command deal with it appropriately.
 896                  */
 897                 switch (scmnd->cmnd[0]) {
 898                 case ATA_16:
 899                 case ATA_12:
 900                         set_host_byte(scmnd, DID_PASSTHROUGH);
 901                         break;
 902                 /*
 903                  * On Some Windows hosts TEST_UNIT_READY command can return
 904                  * SRB_STATUS_ERROR, let the upper level code deal with it
 905                  * based on the sense information.
 906                  */
 907                 case TEST_UNIT_READY:
 908                         break;
 909                 default:
 910                         set_host_byte(scmnd, DID_TARGET_FAILURE);
 911                 }
 912                 break;
 913         case SRB_STATUS_INVALID_LUN:
 914                 do_work = true;
 915                 process_err_fn = storvsc_remove_lun;
 916                 break;
 917         case SRB_STATUS_ABORTED:
 918                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
 919                     (asc == 0x2a) && (ascq == 0x9)) {
 920                         do_work = true;
 921                         process_err_fn = storvsc_device_scan;
 922                         /*
 923                          * Retry the I/O that trigerred this.
 924                          */
 925                         set_host_byte(scmnd, DID_REQUEUE);
 926                 }
 927                 break;
 928         }
 929
 930         if (!do_work)
 931                 return;
 932
 933         /*
 934          * We need to schedule work to process this error; schedule it.
 935          */
 936         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 937         if (!wrk) {
 938                 set_host_byte(scmnd, DID_TARGET_FAILURE);
 939                 return;
 940         }
 941
 942         wrk->host = host;
 943         wrk->lun = vm_srb->lun;
 944         wrk->tgt_id = vm_srb->target_id;
 945         INIT_WORK(&wrk->work, process_err_fn);
 946         schedule_work(&wrk->work);
 947 }
 948
 949
 950 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
 951                                        struct storvsc_device *stor_dev)
 952 {
 953         struct scsi_cmnd *scmnd = cmd_request->cmd;
 954         struct scsi_sense_hdr sense_hdr;
 955         struct vmscsi_request *vm_srb;
 956         struct Scsi_Host *host;
 957         u32 payload_sz = cmd_request->payload_sz;
 958         void *payload = cmd_request->payload;
 959
 960         host = stor_dev->host;
 961
 962         vm_srb = &cmd_request->vstor_packet.vm_srb;
 963
 964         scmnd->result = vm_srb->scsi_status;
 965
 966         if (scmnd->result) {
 967                 if (scsi_normalize_sense(scmnd->sense_buffer,
 968                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
 969                     do_logging(STORVSC_LOGGING_ERROR))
 970                         scsi_print_sense_hdr(scmnd->device, "storvsc",
 971                                              &sense_hdr);
 972         }
 973
 974         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
 975                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
 976                                          sense_hdr.ascq);
 977
 978         scsi_set_resid(scmnd,
 979                 cmd_request->payload->range.len -
 980                 vm_srb->data_transfer_length);
 981
 982         scmnd->scsi_done(scmnd);
 983
 984         if (payload_sz >
 985                 sizeof(struct vmbus_channel_packet_multipage_buffer))
 986                 kfree(payload);
 987 }
 988
 989 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
 990                                   struct vstor_packet *vstor_packet,
 991                                   struct storvsc_cmd_request *request)
 992 {
 993         struct vstor_packet *stor_pkt;
 994         struct hv_device *device = stor_device->device;
 995
 996         stor_pkt = &request->vstor_packet;
 997
 998         /*
 999          * The current SCSI handling on the host side does
1000          * not correctly handle:
1001          * INQUIRY command with page code parameter set to 0x80
1002          * MODE_SENSE command with cmd[2] == 0x1c
1003          *
1004          * Setup srb and scsi status so this won't be fatal.
1005          * We do this so we can distinguish truly fatal failues
1006          * (srb status == 0x4) and off-line the device in that case.
1007          */
1008
1009         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1010            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1011                 vstor_packet->vm_srb.scsi_status = 0;
1012                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1013         }
1014
1015
1016         /* Copy over the status...etc */
1017         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1018         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1019         stor_pkt->vm_srb.sense_info_length =
1020         vstor_packet->vm_srb.sense_info_length;
1021
1022         if (vstor_packet->vm_srb.scsi_status != 0 ||
1023             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1024                 storvsc_log(device, STORVSC_LOGGING_WARN,
1025                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1026                         stor_pkt->vm_srb.cdb[0],
1027                         vstor_packet->vm_srb.scsi_status,
1028                         vstor_packet->vm_srb.srb_status);
1029
1030         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1031                 /* CHECK_CONDITION */
1032                 if (vstor_packet->vm_srb.srb_status &
1033                         SRB_STATUS_AUTOSENSE_VALID) {
1034                         /* autosense data available */
1035
1036                         storvsc_log(device, STORVSC_LOGGING_WARN,
1037                                 "stor pkt %p autosense data valid - len %d\n",
1038                                 request, vstor_packet->vm_srb.sense_info_length);
1039
1040                         memcpy(request->cmd->sense_buffer,
1041                                vstor_packet->vm_srb.sense_data,
1042                                vstor_packet->vm_srb.sense_info_length);
1043
1044                 }
1045         }
1046
1047         stor_pkt->vm_srb.data_transfer_length =
1048         vstor_packet->vm_srb.data_transfer_length;
1049
1050         storvsc_command_completion(request, stor_device);
1051
1052         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1053                 stor_device->drain_notify)
1054                 wake_up(&stor_device->waiting_to_drain);
1055
1056
1057 }
1058
1059 static void storvsc_on_receive(struct storvsc_device *stor_device,
1060                              struct vstor_packet *vstor_packet,
1061                              struct storvsc_cmd_request *request)
1062 {
1063         struct storvsc_scan_work *work;
1064
1065         switch (vstor_packet->operation) {
1066         case VSTOR_OPERATION_COMPLETE_IO:
1067                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1068                 break;
1069
1070         case VSTOR_OPERATION_REMOVE_DEVICE:
1071         case VSTOR_OPERATION_ENUMERATE_BUS:
1072                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1073                 if (!work)
1074                         return;
1075
1076                 INIT_WORK(&work->work, storvsc_host_scan);
1077                 work->host = stor_device->host;
1078                 schedule_work(&work->work);
1079                 break;
1080
1081         case VSTOR_OPERATION_FCHBA_DATA:
1082                 cache_wwn(stor_device, vstor_packet);
1083 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1084                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1085                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1086 #endif
1087                 break;
1088         default:
1089                 break;
1090         }
1091 }
1092
1093 static void storvsc_on_channel_callback(void *context)
1094 {
1095         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1096         struct hv_device *device;
1097         struct storvsc_device *stor_device;
1098         u32 bytes_recvd;
1099         u64 request_id;
1100         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1101         struct storvsc_cmd_request *request;
1102         int ret;
1103
1104         if (channel->primary_channel != NULL)
1105                 device = channel->primary_channel->device_obj;
1106         else
1107                 device = channel->device_obj;
1108
1109         stor_device = get_in_stor_device(device);
1110         if (!stor_device)
1111                 return;
1112
1113         do {
1114                 ret = vmbus_recvpacket(channel, packet,
1115                                        ALIGN((sizeof(struct vstor_packet) -
1116                                              vmscsi_size_delta), 8),
1117                                        &bytes_recvd, &request_id);
1118                 if (ret == 0 && bytes_recvd > 0) {
1119
1120                         request = (struct storvsc_cmd_request *)
1121                                         (unsigned long)request_id;
1122
1123                         if ((request == &stor_device->init_request) ||
1124                             (request == &stor_device->reset_request)) {
1125
1126                                 memcpy(&request->vstor_packet, packet,
1127                                        (sizeof(struct vstor_packet) -
1128                                         vmscsi_size_delta));
1129                                 complete(&request->wait_event);
1130                         } else {
1131                                 storvsc_on_receive(stor_device,
1132                                                 (struct vstor_packet *)packet,
1133                                                 request);
1134                         }
1135                 } else {
1136                         break;
1137                 }
1138         } while (1);
1139
1140         return;
1141 }
1142
1143 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1144                                   bool is_fc)
1145 {
1146         struct vmstorage_channel_properties props;
1147         int ret;
1148
1149         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1150
1151         ret = vmbus_open(device->channel,
1152                          ring_size,
1153                          ring_size,
1154                          (void *)&props,
1155                          sizeof(struct vmstorage_channel_properties),
1156                          storvsc_on_channel_callback, device->channel);
1157
1158         if (ret != 0)
1159                 return ret;
1160
1161         ret = storvsc_channel_init(device, is_fc);
1162
1163         return ret;
1164 }
1165
1166 static int storvsc_dev_remove(struct hv_device *device)
1167 {
1168         struct storvsc_device *stor_device;
1169         unsigned long flags;
1170
1171         stor_device = hv_get_drvdata(device);
1172
1173         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1174         stor_device->destroy = true;
1175         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1176
1177         /*
1178          * At this point, all outbound traffic should be disable. We
1179          * only allow inbound traffic (responses) to proceed so that
1180          * outstanding requests can be completed.
1181          */
1182
1183         storvsc_wait_to_drain(stor_device);
1184
1185         /*
1186          * Since we have already drained, we don't need to busy wait
1187          * as was done in final_release_stor_device()
1188          * Note that we cannot set the ext pointer to NULL until
1189          * we have drained - to drain the outgoing packets, we need to
1190          * allow incoming packets.
1191          */
1192         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1193         hv_set_drvdata(device, NULL);
1194         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1195
1196         /* Close the channel */
1197         vmbus_close(device->channel);
1198
1199         kfree(stor_device);
1200         return 0;
1201 }
1202
1203 static int storvsc_do_io(struct hv_device *device,
1204                          struct storvsc_cmd_request *request)
1205 {
1206         struct storvsc_device *stor_device;
1207         struct vstor_packet *vstor_packet;
1208         struct vmbus_channel *outgoing_channel;
1209         int ret = 0;
1210
1211         vstor_packet = &request->vstor_packet;
1212         stor_device = get_out_stor_device(device);
1213
1214         if (!stor_device)
1215                 return -ENODEV;
1216
1217
1218         request->device  = device;
1219         /*
1220          * Select an an appropriate channel to send the request out.
1221          */
1222
1223         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1224
1225
1226         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1227
1228         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1229                                         vmscsi_size_delta);
1230
1231
1232         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1233
1234
1235         vstor_packet->vm_srb.data_transfer_length =
1236         request->payload->range.len;
1237
1238         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1239
1240         if (request->payload->range.len) {
1241
1242                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1243                                 request->payload, request->payload_sz,
1244                                 vstor_packet,
1245                                 (sizeof(struct vstor_packet) -
1246                                 vmscsi_size_delta),
1247                                 (unsigned long)request);
1248         } else {
1249                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1250                                (sizeof(struct vstor_packet) -
1251                                 vmscsi_size_delta),
1252                                (unsigned long)request,
1253                                VM_PKT_DATA_INBAND,
1254                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1255         }
1256
1257         if (ret != 0)
1258                 return ret;
1259
1260         atomic_inc(&stor_device->num_outstanding_req);
1261
1262         return ret;
1263 }
1264
1265 static int storvsc_device_configure(struct scsi_device *sdevice)
1266 {
1267
1268         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1269
1270         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1271
1272         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1273
1274         /* Ensure there are no gaps in presented sgls */
1275         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1276
1277         sdevice->no_write_same = 1;
1278
1279         /*
1280          * Add blist flags to permit the reading of the VPD pages even when
1281          * the target may claim SPC-2 compliance. MSFT targets currently
1282          * claim SPC-2 compliance while they implement post SPC-2 features.
1283          * With this patch we can correctly handle WRITE_SAME_16 issues.
1284          */
1285         sdevice->sdev_bflags |= msft_blist_flags;
1286
1287         /*
1288          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1289          * if the device is a MSFT virtual device.  If the host is
1290          * WIN10 or newer, allow write_same.
1291          */
1292         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1293                 switch (vmstor_proto_version) {
1294                 case VMSTOR_PROTO_VERSION_WIN8:
1295                 case VMSTOR_PROTO_VERSION_WIN8_1:
1296                         sdevice->scsi_level = SCSI_SPC_3;
1297                         break;
1298                 }
1299
1300                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1301                         sdevice->no_write_same = 0;
1302         }
1303
1304         return 0;
1305 }
1306
1307 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1308                            sector_t capacity, int *info)
1309 {
1310         sector_t nsect = capacity;
1311         sector_t cylinders = nsect;
1312         int heads, sectors_pt;
1313
1314         /*
1315          * We are making up these values; let us keep it simple.
1316          */
1317         heads = 0xff;
1318         sectors_pt = 0x3f;      /* Sectors per track */
1319         sector_div(cylinders, heads * sectors_pt);
1320         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1321                 cylinders = 0xffff;
1322
1323         info[0] = heads;
1324         info[1] = sectors_pt;
1325         info[2] = (int)cylinders;
1326
1327         return 0;
1328 }
1329
1330 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1331 {
1332         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1333         struct hv_device *device = host_dev->dev;
1334
1335         struct storvsc_device *stor_device;
1336         struct storvsc_cmd_request *request;
1337         struct vstor_packet *vstor_packet;
1338         int ret, t;
1339
1340
1341         stor_device = get_out_stor_device(device);
1342         if (!stor_device)
1343                 return FAILED;
1344
1345         request = &stor_device->reset_request;
1346         vstor_packet = &request->vstor_packet;
1347
1348         init_completion(&request->wait_event);
1349
1350         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1351         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1352         vstor_packet->vm_srb.path_id = stor_device->path_id;
1353
1354         ret = vmbus_sendpacket(device->channel, vstor_packet,
1355                                (sizeof(struct vstor_packet) -
1356                                 vmscsi_size_delta),
1357                                (unsigned long)&stor_device->reset_request,
1358                                VM_PKT_DATA_INBAND,
1359                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1360         if (ret != 0)
1361                 return FAILED;
1362
1363         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1364         if (t == 0)
1365                 return TIMEOUT_ERROR;
1366
1367
1368         /*
1369          * At this point, all outstanding requests in the adapter
1370          * should have been flushed out and return to us
1371          * There is a potential race here where the host may be in
1372          * the process of responding when we return from here.
1373          * Just wait for all in-transit packets to be accounted for
1374          * before we return from here.
1375          */
1376         storvsc_wait_to_drain(stor_device);
1377
1378         return SUCCESS;
1379 }
1380
1381 /*
1382  * The host guarantees to respond to each command, although I/O latencies might
1383  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1384  * chance to perform EH.
1385  */
1386 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1387 {
1388         return BLK_EH_RESET_TIMER;
1389 }
1390
1391 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1392 {
1393         bool allowed = true;
1394         u8 scsi_op = scmnd->cmnd[0];
1395
1396         switch (scsi_op) {
1397         /* the host does not handle WRITE_SAME, log accident usage */
1398         case WRITE_SAME:
1399         /*
1400          * smartd sends this command and the host does not handle
1401          * this. So, don't send it.
1402          */
1403         case SET_WINDOW:
1404                 scmnd->result = ILLEGAL_REQUEST << 16;
1405                 allowed = false;
1406                 break;
1407         default:
1408                 break;
1409         }
1410         return allowed;
1411 }
1412
1413 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1414 {
1415         int ret;
1416         struct hv_host_device *host_dev = shost_priv(host);
1417         struct hv_device *dev = host_dev->dev;
1418         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1419         int i;
1420         struct scatterlist *sgl;
1421         unsigned int sg_count = 0;
1422         struct vmscsi_request *vm_srb;
1423         struct scatterlist *cur_sgl;
1424         struct vmbus_packet_mpb_array  *payload;
1425         u32 payload_sz;
1426         u32 length;
1427
1428         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1429                 /*
1430                  * On legacy hosts filter unimplemented commands.
1431                  * Future hosts are expected to correctly handle
1432                  * unsupported commands. Furthermore, it is
1433                  * possible that some of the currently
1434                  * unsupported commands maybe supported in
1435                  * future versions of the host.
1436                  */
1437                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1438                         scmnd->scsi_done(scmnd);
1439                         return 0;
1440                 }
1441         }
1442
1443         /* Setup the cmd request */
1444         cmd_request->cmd = scmnd;
1445
1446         vm_srb = &cmd_request->vstor_packet.vm_srb;
1447         vm_srb->win8_extension.time_out_value = 60;
1448
1449         vm_srb->win8_extension.srb_flags |=
1450                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1451
1452         /* Build the SRB */
1453         switch (scmnd->sc_data_direction) {
1454         case DMA_TO_DEVICE:
1455                 vm_srb->data_in = WRITE_TYPE;
1456                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1457                 break;
1458         case DMA_FROM_DEVICE:
1459                 vm_srb->data_in = READ_TYPE;
1460                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1461                 break;
1462         case DMA_NONE:
1463                 vm_srb->data_in = UNKNOWN_TYPE;
1464                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1465                 break;
1466         default:
1467                 /*
1468                  * This is DMA_BIDIRECTIONAL or something else we are never
1469                  * supposed to see here.
1470                  */
1471                 WARN(1, "Unexpected data direction: %d\n",
1472                      scmnd->sc_data_direction);
1473                 return -EINVAL;
1474         }
1475
1476
1477         vm_srb->port_number = host_dev->port;
1478         vm_srb->path_id = scmnd->device->channel;
1479         vm_srb->target_id = scmnd->device->id;
1480         vm_srb->lun = scmnd->device->lun;
1481
1482         vm_srb->cdb_length = scmnd->cmd_len;
1483
1484         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1485
1486         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1487         sg_count = scsi_sg_count(scmnd);
1488
1489         length = scsi_bufflen(scmnd);
1490         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1491         payload_sz = sizeof(cmd_request->mpb);
1492
1493         if (sg_count) {
1494                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1495
1496                         payload_sz = (sg_count * sizeof(void *) +
1497                                       sizeof(struct vmbus_packet_mpb_array));
1498                         payload = kmalloc(payload_sz, GFP_ATOMIC);
1499                         if (!payload)
1500                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1501                 }
1502
1503                 payload->range.len = length;
1504                 payload->range.offset = sgl[0].offset;
1505
1506                 cur_sgl = sgl;
1507                 for (i = 0; i < sg_count; i++) {
1508                         payload->range.pfn_array[i] =
1509                                 page_to_pfn(sg_page((cur_sgl)));
1510                         cur_sgl = sg_next(cur_sgl);
1511                 }
1512
1513         } else if (scsi_sglist(scmnd)) {
1514                 payload->range.len = length;
1515                 payload->range.offset =
1516                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1517                 payload->range.pfn_array[0] =
1518                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1519         }
1520
1521         cmd_request->payload = payload;
1522         cmd_request->payload_sz = payload_sz;
1523
1524         /* Invokes the vsc to start an IO */
1525         ret = storvsc_do_io(dev, cmd_request);
1526
1527         if (ret == -EAGAIN) {
1528                 /* no more space */
1529                 return SCSI_MLQUEUE_DEVICE_BUSY;
1530         }
1531
1532         return 0;
1533 }
1534
1535 static struct scsi_host_template scsi_driver = {
1536         .module =               THIS_MODULE,
1537         .name =                 "storvsc_host_t",
1538         .cmd_size =             sizeof(struct storvsc_cmd_request),
1539         .bios_param =           storvsc_get_chs,
1540         .queuecommand =         storvsc_queuecommand,
1541         .eh_host_reset_handler =        storvsc_host_reset_handler,
1542         .proc_name =            "storvsc_host",
1543         .eh_timed_out =         storvsc_eh_timed_out,
1544         .slave_configure =      storvsc_device_configure,
1545         .cmd_per_lun =          255,
1546         .this_id =              -1,
1547         .use_clustering =       ENABLE_CLUSTERING,
1548         /* Make sure we dont get a sg segment crosses a page boundary */
1549         .dma_boundary =         PAGE_SIZE-1,
1550         .no_write_same =        1,
1551 };
1552
1553 enum {
1554         SCSI_GUID,
1555         IDE_GUID,
1556         SFC_GUID,
1557 };
1558
1559 static const struct hv_vmbus_device_id id_table[] = {
1560         /* SCSI guid */
1561         { HV_SCSI_GUID,
1562           .driver_data = SCSI_GUID
1563         },
1564         /* IDE guid */
1565         { HV_IDE_GUID,
1566           .driver_data = IDE_GUID
1567         },
1568         /* Fibre Channel GUID */
1569         {
1570           HV_SYNTHFC_GUID,
1571           .driver_data = SFC_GUID
1572         },
1573         { },
1574 };
1575
1576 MODULE_DEVICE_TABLE(vmbus, id_table);
1577
1578 static int storvsc_probe(struct hv_device *device,
1579                         const struct hv_vmbus_device_id *dev_id)
1580 {
1581         int ret;
1582         int num_cpus = num_online_cpus();
1583         struct Scsi_Host *host;
1584         struct hv_host_device *host_dev;
1585         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1586         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1587         int target = 0;
1588         struct storvsc_device *stor_device;
1589         int max_luns_per_target;
1590         int max_targets;
1591         int max_channels;
1592         int max_sub_channels = 0;
1593
1594         /*
1595          * Based on the windows host we are running on,
1596          * set state to properly communicate with the host.
1597          */
1598
1599         if (vmbus_proto_version < VERSION_WIN8) {
1600                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1601                 max_targets = STORVSC_IDE_MAX_TARGETS;
1602                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1603         } else {
1604                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1605                 max_targets = STORVSC_MAX_TARGETS;
1606                 max_channels = STORVSC_MAX_CHANNELS;
1607                 /*
1608                  * On Windows8 and above, we support sub-channels for storage.
1609                  * The number of sub-channels offerred is based on the number of
1610                  * VCPUs in the guest.
1611                  */
1612                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1613         }
1614
1615         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1616                                  (max_sub_channels + 1));
1617
1618         host = scsi_host_alloc(&scsi_driver,
1619                                sizeof(struct hv_host_device));
1620         if (!host)
1621                 return -ENOMEM;
1622
1623         host_dev = shost_priv(host);
1624         memset(host_dev, 0, sizeof(struct hv_host_device));
1625
1626         host_dev->port = host->host_no;
1627         host_dev->dev = device;
1628
1629
1630         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1631         if (!stor_device) {
1632                 ret = -ENOMEM;
1633                 goto err_out0;
1634         }
1635
1636         stor_device->destroy = false;
1637         stor_device->open_sub_channel = false;
1638         init_waitqueue_head(&stor_device->waiting_to_drain);
1639         stor_device->device = device;
1640         stor_device->host = host;
1641         hv_set_drvdata(device, stor_device);
1642
1643         stor_device->port_number = host->host_no;
1644         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1645         if (ret)
1646                 goto err_out1;
1647
1648         host_dev->path = stor_device->path_id;
1649         host_dev->target = stor_device->target_id;
1650
1651         switch (dev_id->driver_data) {
1652         case SFC_GUID:
1653                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1654                 host->max_id = STORVSC_FC_MAX_TARGETS;
1655                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1656 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1657                 host->transportt = fc_transport_template;
1658 #endif
1659                 break;
1660
1661         case SCSI_GUID:
1662                 host->max_lun = max_luns_per_target;
1663                 host->max_id = max_targets;
1664                 host->max_channel = max_channels - 1;
1665                 break;
1666
1667         default:
1668                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1669                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1670                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1671                 break;
1672         }
1673         /* max cmd length */
1674         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1675
1676         /*
1677          * set the table size based on the info we got
1678          * from the host.
1679          */
1680         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1681
1682         /* Register the HBA and start the scsi bus scan */
1683         ret = scsi_add_host(host, &device->device);
1684         if (ret != 0)
1685                 goto err_out2;
1686
1687         if (!dev_is_ide) {
1688                 scsi_scan_host(host);
1689         } else {
1690                 target = (device->dev_instance.b[5] << 8 |
1691                          device->dev_instance.b[4]);
1692                 ret = scsi_add_device(host, 0, target, 0);
1693                 if (ret) {
1694                         scsi_remove_host(host);
1695                         goto err_out2;
1696                 }
1697         }
1698 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1699         if (host->transportt == fc_transport_template) {
1700                 fc_host_node_name(host) = stor_device->node_name;
1701                 fc_host_port_name(host) = stor_device->port_name;
1702         }
1703 #endif
1704         return 0;
1705
1706 err_out2:
1707         /*
1708          * Once we have connected with the host, we would need to
1709          * to invoke storvsc_dev_remove() to rollback this state and
1710          * this call also frees up the stor_device; hence the jump around
1711          * err_out1 label.
1712          */
1713         storvsc_dev_remove(device);
1714         goto err_out0;
1715
1716 err_out1:
1717         kfree(stor_device);
1718
1719 err_out0:
1720         scsi_host_put(host);
1721         return ret;
1722 }
1723
1724 static int storvsc_remove(struct hv_device *dev)
1725 {
1726         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1727         struct Scsi_Host *host = stor_device->host;
1728
1729 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1730         if (host->transportt == fc_transport_template)
1731                 fc_remove_host(host);
1732 #endif
1733         scsi_remove_host(host);
1734         storvsc_dev_remove(dev);
1735         scsi_host_put(host);
1736
1737         return 0;
1738 }
1739
1740 static struct hv_driver storvsc_drv = {
1741         .name = KBUILD_MODNAME,
1742         .id_table = id_table,
1743         .probe = storvsc_probe,
1744         .remove = storvsc_remove,
1745 };
1746
1747 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1748 static struct fc_function_template fc_transport_functions = {
1749         .show_host_node_name = 1,
1750         .show_host_port_name = 1,
1751 };
1752 #endif
1753
1754 static int __init storvsc_drv_init(void)
1755 {
1756         int ret;
1757
1758         /*
1759          * Divide the ring buffer data size (which is 1 page less
1760          * than the ring buffer size since that page is reserved for
1761          * the ring buffer indices) by the max request size (which is
1762          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1763          */
1764         max_outstanding_req_per_channel =
1765                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1766                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1767                 sizeof(struct vstor_packet) + sizeof(u64) -
1768                 vmscsi_size_delta,
1769                 sizeof(u64)));
1770
1771 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1772         fc_transport_template = fc_attach_transport(&fc_transport_functions);
1773         if (!fc_transport_template)
1774                 return -ENODEV;
1775
1776         /*
1777          * Install Hyper-V specific timeout handler.
1778          */
1779         fc_transport_template->eh_timed_out = storvsc_eh_timed_out;
1780 #endif
1781
1782         ret = vmbus_driver_register(&storvsc_drv);
1783
1784 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1785         if (ret)
1786                 fc_release_transport(fc_transport_template);
1787 #endif
1788
1789         return ret;
1790 }
1791
1792 static void __exit storvsc_drv_exit(void)
1793 {
1794         vmbus_driver_unregister(&storvsc_drv);
1795 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1796         fc_release_transport(fc_transport_template);
1797 #endif
1798 }
1799
1800 MODULE_LICENSE("GPL");
1801 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1802 module_init(storvsc_drv_init);
1803 module_exit(storvsc_drv_exit);