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 #define SP_UNTAGGED                     ((unsigned char) ~0)
 140 #define SRB_SIMPLE_TAG_REQUEST          0x20
 141
 142 /*
 143  * Platform neutral description of a scsi request -
 144  * this remains the same across the write regardless of 32/64 bit
 145  * note: it's patterned off the SCSI_PASS_THROUGH structure
 146  */
 147 #define STORVSC_MAX_CMD_LEN                     0x10
 148
 149 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 150 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 151
 152 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 153 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 154
 155 /*
 156  * Sense buffer size changed in win8; have a run-time
 157  * variable to track the size we should use.  This value will
 158  * likely change during protocol negotiation but it is valid
 159  * to start by assuming pre-Win8.
 160  */
 161 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 162
 163 /*
 164  * The storage protocol version is determined during the
 165  * initial exchange with the host.  It will indicate which
 166  * storage functionality is available in the host.
 167 */
 168 static int vmstor_proto_version;
 169
 170 #define STORVSC_LOGGING_NONE    0
 171 #define STORVSC_LOGGING_ERROR   1
 172 #define STORVSC_LOGGING_WARN    2
 173
 174 static int logging_level = STORVSC_LOGGING_ERROR;
 175 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 176 MODULE_PARM_DESC(logging_level,
 177         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 178
 179 static inline bool do_logging(int level)
 180 {
 181         return logging_level >= level;
 182 }
 183
 184 #define storvsc_log(dev, level, fmt, ...)                       \
 185 do {                                                            \
 186         if (do_logging(level))                                  \
 187                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 188 } while (0)
 189
 190 struct vmscsi_win8_extension {
 191         /*
 192          * The following were added in Windows 8
 193          */
 194         u16 reserve;
 195         u8  queue_tag;
 196         u8  queue_action;
 197         u32 srb_flags;
 198         u32 time_out_value;
 199         u32 queue_sort_ey;
 200 } __packed;
 201
 202 struct vmscsi_request {
 203         u16 length;
 204         u8 srb_status;
 205         u8 scsi_status;
 206
 207         u8  port_number;
 208         u8  path_id;
 209         u8  target_id;
 210         u8  lun;
 211
 212         u8  cdb_length;
 213         u8  sense_info_length;
 214         u8  data_in;
 215         u8  reserved;
 216
 217         u32 data_transfer_length;
 218
 219         union {
 220                 u8 cdb[STORVSC_MAX_CMD_LEN];
 221                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 222                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 223         };
 224         /*
 225          * The following was added in win8.
 226          */
 227         struct vmscsi_win8_extension win8_extension;
 228
 229 } __attribute((packed));
 230
 231
 232 /*
 233  * The size of the vmscsi_request has changed in win8. The
 234  * additional size is because of new elements added to the
 235  * structure. These elements are valid only when we are talking
 236  * to a win8 host.
 237  * Track the correction to size we need to apply. This value
 238  * will likely change during protocol negotiation but it is
 239  * valid to start by assuming pre-Win8.
 240  */
 241 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 242
 243 /*
 244  * The list of storage protocols in order of preference.
 245  */
 246 struct vmstor_protocol {
 247         int protocol_version;
 248         int sense_buffer_size;
 249         int vmscsi_size_delta;
 250 };
 251
 252
 253 static const struct vmstor_protocol vmstor_protocols[] = {
 254         {
 255                 VMSTOR_PROTO_VERSION_WIN10,
 256                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 257                 0
 258         },
 259         {
 260                 VMSTOR_PROTO_VERSION_WIN8_1,
 261                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 262                 0
 263         },
 264         {
 265                 VMSTOR_PROTO_VERSION_WIN8,
 266                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 267                 0
 268         },
 269         {
 270                 VMSTOR_PROTO_VERSION_WIN7,
 271                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 272                 sizeof(struct vmscsi_win8_extension),
 273         },
 274         {
 275                 VMSTOR_PROTO_VERSION_WIN6,
 276                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 277                 sizeof(struct vmscsi_win8_extension),
 278         }
 279 };
 280
 281
 282 /*
 283  * This structure is sent during the intialization phase to get the different
 284  * properties of the channel.
 285  */
 286
 287 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 288
 289 struct vmstorage_channel_properties {
 290         u32 reserved;
 291         u16 max_channel_cnt;
 292         u16 reserved1;
 293
 294         u32 flags;
 295         u32   max_transfer_bytes;
 296
 297         u64  reserved2;
 298 } __packed;
 299
 300 /*  This structure is sent during the storage protocol negotiations. */
 301 struct vmstorage_protocol_version {
 302         /* Major (MSW) and minor (LSW) version numbers. */
 303         u16 major_minor;
 304
 305         /*
 306          * Revision number is auto-incremented whenever this file is changed
 307          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 308          * definitely indicate incompatibility--but it does indicate mismatched
 309          * builds.
 310          * This is only used on the windows side. Just set it to 0.
 311          */
 312         u16 revision;
 313 } __packed;
 314
 315 /* Channel Property Flags */
 316 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 317 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 318
 319 struct vstor_packet {
 320         /* Requested operation type */
 321         enum vstor_packet_operation operation;
 322
 323         /*  Flags - see below for values */
 324         u32 flags;
 325
 326         /* Status of the request returned from the server side. */
 327         u32 status;
 328
 329         /* Data payload area */
 330         union {
 331                 /*
 332                  * Structure used to forward SCSI commands from the
 333                  * client to the server.
 334                  */
 335                 struct vmscsi_request vm_srb;
 336
 337                 /* Structure used to query channel properties. */
 338                 struct vmstorage_channel_properties storage_channel_properties;
 339
 340                 /* Used during version negotiations. */
 341                 struct vmstorage_protocol_version version;
 342
 343                 /* Fibre channel address packet */
 344                 struct hv_fc_wwn_packet wwn_packet;
 345
 346                 /* Number of sub-channels to create */
 347                 u16 sub_channel_count;
 348
 349                 /* This will be the maximum of the union members */
 350                 u8  buffer[0x34];
 351         };
 352 } __packed;
 353
 354 /*
 355  * Packet Flags:
 356  *
 357  * This flag indicates that the server should send back a completion for this
 358  * packet.
 359  */
 360
 361 #define REQUEST_COMPLETION_FLAG 0x1
 362
 363 /* Matches Windows-end */
 364 enum storvsc_request_type {
 365         WRITE_TYPE = 0,
 366         READ_TYPE,
 367         UNKNOWN_TYPE,
 368 };
 369
 370 /*
 371  * SRB status codes and masks; a subset of the codes used here.
 372  */
 373
 374 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 375 #define SRB_STATUS_QUEUE_FROZEN         0x40
 376 #define SRB_STATUS_INVALID_LUN  0x20
 377 #define SRB_STATUS_SUCCESS      0x01
 378 #define SRB_STATUS_ABORTED      0x02
 379 #define SRB_STATUS_ERROR        0x04
 380 #define SRB_STATUS_DATA_OVERRUN 0x12
 381
 382 #define SRB_STATUS(status) \
 383         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 384 /*
 385  * This is the end of Protocol specific defines.
 386  */
 387
 388 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 389 static u32 max_outstanding_req_per_channel;
 390
 391 static int storvsc_vcpus_per_sub_channel = 4;
 392
 393 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 394 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 395
 396 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 397 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 398 /*
 399  * Timeout in seconds for all devices managed by this driver.
 400  */
 401 static int storvsc_timeout = 180;
 402
 403 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 404 static struct scsi_transport_template *fc_transport_template;
 405 #endif
 406
 407 static void storvsc_on_channel_callback(void *context);
 408
 409 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 410 #define STORVSC_MAX_TARGETS                             2
 411 #define STORVSC_MAX_CHANNELS                            8
 412
 413 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 414 #define STORVSC_FC_MAX_TARGETS                          128
 415 #define STORVSC_FC_MAX_CHANNELS                         8
 416
 417 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 418 #define STORVSC_IDE_MAX_TARGETS                         1
 419 #define STORVSC_IDE_MAX_CHANNELS                        1
 420
 421 struct storvsc_cmd_request {
 422         struct scsi_cmnd *cmd;
 423
 424         struct hv_device *device;
 425
 426         /* Synchronize the request/response if needed */
 427         struct completion wait_event;
 428
 429         struct vmbus_channel_packet_multipage_buffer mpb;
 430         struct vmbus_packet_mpb_array *payload;
 431         u32 payload_sz;
 432
 433         struct vstor_packet vstor_packet;
 434 };
 435
 436
 437 /* A storvsc device is a device object that contains a vmbus channel */
 438 struct storvsc_device {
 439         struct hv_device *device;
 440
 441         bool     destroy;
 442         bool     drain_notify;
 443         bool     open_sub_channel;
 444         atomic_t num_outstanding_req;
 445         struct Scsi_Host *host;
 446
 447         wait_queue_head_t waiting_to_drain;
 448
 449         /*
 450          * Each unique Port/Path/Target represents 1 channel ie scsi
 451          * controller. In reality, the pathid, targetid is always 0
 452          * and the port is set by us
 453          */
 454         unsigned int port_number;
 455         unsigned char path_id;
 456         unsigned char target_id;
 457
 458         /*
 459          * Max I/O, the device can support.
 460          */
 461         u32   max_transfer_bytes;
 462         /* Used for vsc/vsp channel reset process */
 463         struct storvsc_cmd_request init_request;
 464         struct storvsc_cmd_request reset_request;
 465         /*
 466          * Currently active port and node names for FC devices.
 467          */
 468         u64 node_name;
 469         u64 port_name;
 470 };
 471
 472 struct hv_host_device {
 473         struct hv_device *dev;
 474         unsigned int port;
 475         unsigned char path;
 476         unsigned char target;
 477 };
 478
 479 struct storvsc_scan_work {
 480         struct work_struct work;
 481         struct Scsi_Host *host;
 482         u8 lun;
 483         u8 tgt_id;
 484 };
 485
 486 static void storvsc_device_scan(struct work_struct *work)
 487 {
 488         struct storvsc_scan_work *wrk;
 489         struct scsi_device *sdev;
 490
 491         wrk = container_of(work, struct storvsc_scan_work, work);
 492
 493         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 494         if (!sdev)
 495                 goto done;
 496         scsi_rescan_device(&sdev->sdev_gendev);
 497         scsi_device_put(sdev);
 498
 499 done:
 500         kfree(wrk);
 501 }
 502
 503 static void storvsc_host_scan(struct work_struct *work)
 504 {
 505         struct storvsc_scan_work *wrk;
 506         struct Scsi_Host *host;
 507         struct scsi_device *sdev;
 508
 509         wrk = container_of(work, struct storvsc_scan_work, work);
 510         host = wrk->host;
 511
 512         /*
 513          * Before scanning the host, first check to see if any of the
 514          * currrently known devices have been hot removed. We issue a
 515          * "unit ready" command against all currently known devices.
 516          * This I/O will result in an error for devices that have been
 517          * removed. As part of handling the I/O error, we remove the device.
 518          *
 519          * When a LUN is added or removed, the host sends us a signal to
 520          * scan the host. Thus we are forced to discover the LUNs that
 521          * may have been removed this way.
 522          */
 523         mutex_lock(&host->scan_mutex);
 524         shost_for_each_device(sdev, host)
 525                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 526         mutex_unlock(&host->scan_mutex);
 527         /*
 528          * Now scan the host to discover LUNs that may have been added.
 529          */
 530         scsi_scan_host(host);
 531
 532         kfree(wrk);
 533 }
 534
 535 static void storvsc_remove_lun(struct work_struct *work)
 536 {
 537         struct storvsc_scan_work *wrk;
 538         struct scsi_device *sdev;
 539
 540         wrk = container_of(work, struct storvsc_scan_work, work);
 541         if (!scsi_host_get(wrk->host))
 542                 goto done;
 543
 544         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 545
 546         if (sdev) {
 547                 scsi_remove_device(sdev);
 548                 scsi_device_put(sdev);
 549         }
 550         scsi_host_put(wrk->host);
 551
 552 done:
 553         kfree(wrk);
 554 }
 555
 556
 557 /*
 558  * We can get incoming messages from the host that are not in response to
 559  * messages that we have sent out. An example of this would be messages
 560  * received by the guest to notify dynamic addition/removal of LUNs. To
 561  * deal with potential race conditions where the driver may be in the
 562  * midst of being unloaded when we might receive an unsolicited message
 563  * from the host, we have implemented a mechanism to gurantee sequential
 564  * consistency:
 565  *
 566  * 1) Once the device is marked as being destroyed, we will fail all
 567  *    outgoing messages.
 568  * 2) We permit incoming messages when the device is being destroyed,
 569  *    only to properly account for messages already sent out.
 570  */
 571
 572 static inline struct storvsc_device *get_out_stor_device(
 573                                         struct hv_device *device)
 574 {
 575         struct storvsc_device *stor_device;
 576
 577         stor_device = hv_get_drvdata(device);
 578
 579         if (stor_device && stor_device->destroy)
 580                 stor_device = NULL;
 581
 582         return stor_device;
 583 }
 584
 585
 586 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 587 {
 588         dev->drain_notify = true;
 589         wait_event(dev->waiting_to_drain,
 590                    atomic_read(&dev->num_outstanding_req) == 0);
 591         dev->drain_notify = false;
 592 }
 593
 594 static inline struct storvsc_device *get_in_stor_device(
 595                                         struct hv_device *device)
 596 {
 597         struct storvsc_device *stor_device;
 598
 599         stor_device = hv_get_drvdata(device);
 600
 601         if (!stor_device)
 602                 goto get_in_err;
 603
 604         /*
 605          * If the device is being destroyed; allow incoming
 606          * traffic only to cleanup outstanding requests.
 607          */
 608
 609         if (stor_device->destroy  &&
 610                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 611                 stor_device = NULL;
 612
 613 get_in_err:
 614         return stor_device;
 615
 616 }
 617
 618 static void handle_sc_creation(struct vmbus_channel *new_sc)
 619 {
 620         struct hv_device *device = new_sc->primary_channel->device_obj;
 621         struct storvsc_device *stor_device;
 622         struct vmstorage_channel_properties props;
 623
 624         stor_device = get_out_stor_device(device);
 625         if (!stor_device)
 626                 return;
 627
 628         if (stor_device->open_sub_channel == false)
 629                 return;
 630
 631         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 632
 633         vmbus_open(new_sc,
 634                    storvsc_ringbuffer_size,
 635                    storvsc_ringbuffer_size,
 636                    (void *)&props,
 637                    sizeof(struct vmstorage_channel_properties),
 638                    storvsc_on_channel_callback, new_sc);
 639 }
 640
 641 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 642 {
 643         struct storvsc_device *stor_device;
 644         int num_sc;
 645         struct storvsc_cmd_request *request;
 646         struct vstor_packet *vstor_packet;
 647         int ret, t;
 648
 649         /*
 650          * If the number of CPUs is artificially restricted, such as
 651          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 652          * sub-channels >= the number of CPUs. These sub-channels
 653          * should not be created. The primary channel is already created
 654          * and assigned to one CPU, so check against # CPUs - 1.
 655          */
 656         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 657         if (!num_sc)
 658                 return;
 659
 660         stor_device = get_out_stor_device(device);
 661         if (!stor_device)
 662                 return;
 663
 664         request = &stor_device->init_request;
 665         vstor_packet = &request->vstor_packet;
 666
 667         stor_device->open_sub_channel = true;
 668         /*
 669          * Establish a handler for dealing with subchannels.
 670          */
 671         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 672
 673         /*
 674          * Check to see if sub-channels have already been created. This
 675          * can happen when this driver is re-loaded after unloading.
 676          */
 677
 678         if (vmbus_are_subchannels_present(device->channel))
 679                 return;
 680
 681         stor_device->open_sub_channel = false;
 682         /*
 683          * Request the host to create sub-channels.
 684          */
 685         memset(request, 0, sizeof(struct storvsc_cmd_request));
 686         init_completion(&request->wait_event);
 687         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 688         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 689         vstor_packet->sub_channel_count = num_sc;
 690
 691         ret = vmbus_sendpacket(device->channel, vstor_packet,
 692                                (sizeof(struct vstor_packet) -
 693                                vmscsi_size_delta),
 694                                (unsigned long)request,
 695                                VM_PKT_DATA_INBAND,
 696                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 697
 698         if (ret != 0)
 699                 return;
 700
 701         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 702         if (t == 0)
 703                 return;
 704
 705         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 706             vstor_packet->status != 0)
 707                 return;
 708
 709         /*
 710          * Now that we created the sub-channels, invoke the check; this
 711          * may trigger the callback.
 712          */
 713         stor_device->open_sub_channel = true;
 714         vmbus_are_subchannels_present(device->channel);
 715 }
 716
 717 static void cache_wwn(struct storvsc_device *stor_device,
 718                       struct vstor_packet *vstor_packet)
 719 {
 720         /*
 721          * Cache the currently active port and node ww names.
 722          */
 723         if (vstor_packet->wwn_packet.primary_active) {
 724                 stor_device->node_name =
 725                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 726                 stor_device->port_name =
 727                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 728         } else {
 729                 stor_device->node_name =
 730                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 731                 stor_device->port_name =
 732                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 733         }
 734 }
 735
 736
 737 static int storvsc_execute_vstor_op(struct hv_device *device,
 738                                     struct storvsc_cmd_request *request,
 739                                     bool status_check)
 740 {
 741         struct vstor_packet *vstor_packet;
 742         int ret, t;
 743
 744         vstor_packet = &request->vstor_packet;
 745
 746         init_completion(&request->wait_event);
 747         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 748
 749         ret = vmbus_sendpacket(device->channel, vstor_packet,
 750                                (sizeof(struct vstor_packet) -
 751                                vmscsi_size_delta),
 752                                (unsigned long)request,
 753                                VM_PKT_DATA_INBAND,
 754                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 755         if (ret != 0)
 756                 return ret;
 757
 758         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 759         if (t == 0)
 760                 return -ETIMEDOUT;
 761
 762         if (!status_check)
 763                 return ret;
 764
 765         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 766             vstor_packet->status != 0)
 767                 return -EINVAL;
 768
 769         return ret;
 770 }
 771
 772 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 773 {
 774         struct storvsc_device *stor_device;
 775         struct storvsc_cmd_request *request;
 776         struct vstor_packet *vstor_packet;
 777         int ret, i;
 778         int max_chns;
 779         bool process_sub_channels = false;
 780
 781         stor_device = get_out_stor_device(device);
 782         if (!stor_device)
 783                 return -ENODEV;
 784
 785         request = &stor_device->init_request;
 786         vstor_packet = &request->vstor_packet;
 787
 788         /*
 789          * Now, initiate the vsc/vsp initialization protocol on the open
 790          * channel
 791          */
 792         memset(request, 0, sizeof(struct storvsc_cmd_request));
 793         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 794         ret = storvsc_execute_vstor_op(device, request, true);
 795         if (ret)
 796                 return ret;
 797         /*
 798          * Query host supported protocol version.
 799          */
 800
 801         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 802                 /* reuse the packet for version range supported */
 803                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 804                 vstor_packet->operation =
 805                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 806
 807                 vstor_packet->version.major_minor =
 808                         vmstor_protocols[i].protocol_version;
 809
 810                 /*
 811                  * The revision number is only used in Windows; set it to 0.
 812                  */
 813                 vstor_packet->version.revision = 0;
 814                 ret = storvsc_execute_vstor_op(device, request, false);
 815                 if (ret != 0)
 816                         return ret;
 817
 818                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 819                         return -EINVAL;
 820
 821                 if (vstor_packet->status == 0) {
 822                         vmstor_proto_version =
 823                                 vmstor_protocols[i].protocol_version;
 824
 825                         sense_buffer_size =
 826                                 vmstor_protocols[i].sense_buffer_size;
 827
 828                         vmscsi_size_delta =
 829                                 vmstor_protocols[i].vmscsi_size_delta;
 830
 831                         break;
 832                 }
 833         }
 834
 835         if (vstor_packet->status != 0)
 836                 return -EINVAL;
 837
 838
 839         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 840         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 841         ret = storvsc_execute_vstor_op(device, request, true);
 842         if (ret != 0)
 843                 return ret;
 844
 845         /*
 846          * Check to see if multi-channel support is there.
 847          * Hosts that implement protocol version of 5.1 and above
 848          * support multi-channel.
 849          */
 850         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 851         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 852                 if (vstor_packet->storage_channel_properties.flags &
 853                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 854                         process_sub_channels = true;
 855         }
 856         stor_device->max_transfer_bytes =
 857                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 858
 859         if (!is_fc)
 860                 goto done;
 861
 862         /*
 863          * For FC devices retrieve FC HBA data.
 864          */
 865         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 866         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 867         ret = storvsc_execute_vstor_op(device, request, true);
 868         if (ret != 0)
 869                 return ret;
 870
 871         /*
 872          * Cache the currently active port and node ww names.
 873          */
 874         cache_wwn(stor_device, vstor_packet);
 875
 876 done:
 877
 878         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 879         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 880         ret = storvsc_execute_vstor_op(device, request, true);
 881         if (ret != 0)
 882                 return ret;
 883
 884         if (process_sub_channels)
 885                 handle_multichannel_storage(device, max_chns);
 886
 887         return ret;
 888 }
 889
 890 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 891                                 struct scsi_cmnd *scmnd,
 892                                 struct Scsi_Host *host,
 893                                 u8 asc, u8 ascq)
 894 {
 895         struct storvsc_scan_work *wrk;
 896         void (*process_err_fn)(struct work_struct *work);
 897         bool do_work = false;
 898
 899         switch (SRB_STATUS(vm_srb->srb_status)) {
 900         case SRB_STATUS_ERROR:
 901                 /*
 902                  * Let upper layer deal with error when
 903                  * sense message is present.
 904                  */
 905
 906                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
 907                         break;
 908                 /*
 909                  * If there is an error; offline the device since all
 910                  * error recovery strategies would have already been
 911                  * deployed on the host side. However, if the command
 912                  * were a pass-through command deal with it appropriately.
 913                  */
 914                 switch (scmnd->cmnd[0]) {
 915                 case ATA_16:
 916                 case ATA_12:
 917                         set_host_byte(scmnd, DID_PASSTHROUGH);
 918                         break;
 919                 /*
 920                  * On Some Windows hosts TEST_UNIT_READY command can return
 921                  * SRB_STATUS_ERROR, let the upper level code deal with it
 922                  * based on the sense information.
 923                  */
 924                 case TEST_UNIT_READY:
 925                         break;
 926                 default:
 927                         set_host_byte(scmnd, DID_ERROR);
 928                 }
 929                 break;
 930         case SRB_STATUS_INVALID_LUN:
 931                 set_host_byte(scmnd, DID_NO_CONNECT);
 932                 do_work = true;
 933                 process_err_fn = storvsc_remove_lun;
 934                 break;
 935         case SRB_STATUS_ABORTED:
 936                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
 937                     (asc == 0x2a) && (ascq == 0x9)) {
 938                         do_work = true;
 939                         process_err_fn = storvsc_device_scan;
 940                         /*
 941                          * Retry the I/O that trigerred this.
 942                          */
 943                         set_host_byte(scmnd, DID_REQUEUE);
 944                 }
 945                 break;
 946         }
 947
 948         if (!do_work)
 949                 return;
 950
 951         /*
 952          * We need to schedule work to process this error; schedule it.
 953          */
 954         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 955         if (!wrk) {
 956                 set_host_byte(scmnd, DID_TARGET_FAILURE);
 957                 return;
 958         }
 959
 960         wrk->host = host;
 961         wrk->lun = vm_srb->lun;
 962         wrk->tgt_id = vm_srb->target_id;
 963         INIT_WORK(&wrk->work, process_err_fn);
 964         schedule_work(&wrk->work);
 965 }
 966
 967
 968 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
 969                                        struct storvsc_device *stor_dev)
 970 {
 971         struct scsi_cmnd *scmnd = cmd_request->cmd;
 972         struct scsi_sense_hdr sense_hdr;
 973         struct vmscsi_request *vm_srb;
 974         u32 data_transfer_length;
 975         struct Scsi_Host *host;
 976         u32 payload_sz = cmd_request->payload_sz;
 977         void *payload = cmd_request->payload;
 978
 979         host = stor_dev->host;
 980
 981         vm_srb = &cmd_request->vstor_packet.vm_srb;
 982         data_transfer_length = vm_srb->data_transfer_length;
 983
 984         scmnd->result = vm_srb->scsi_status;
 985
 986         if (scmnd->result) {
 987                 if (scsi_normalize_sense(scmnd->sense_buffer,
 988                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
 989                     !(sense_hdr.sense_key == NOT_READY &&
 990                                  sense_hdr.asc == 0x03A) &&
 991                     do_logging(STORVSC_LOGGING_ERROR))
 992                         scsi_print_sense_hdr(scmnd->device, "storvsc",
 993                                              &sense_hdr);
 994         }
 995
 996         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
 997                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
 998                                          sense_hdr.ascq);
 999                 /*
1000                  * The Windows driver set data_transfer_length on
1001                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1002                  * is untouched.  In these cases we set it to 0.
1003                  */
1004                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1005                         data_transfer_length = 0;
1006         }
1007
1008         scsi_set_resid(scmnd,
1009                 cmd_request->payload->range.len - data_transfer_length);
1010
1011         scmnd->scsi_done(scmnd);
1012
1013         if (payload_sz >
1014                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1015                 kfree(payload);
1016 }
1017
1018 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1019                                   struct vstor_packet *vstor_packet,
1020                                   struct storvsc_cmd_request *request)
1021 {
1022         struct vstor_packet *stor_pkt;
1023         struct hv_device *device = stor_device->device;
1024
1025         stor_pkt = &request->vstor_packet;
1026
1027         /*
1028          * The current SCSI handling on the host side does
1029          * not correctly handle:
1030          * INQUIRY command with page code parameter set to 0x80
1031          * MODE_SENSE command with cmd[2] == 0x1c
1032          *
1033          * Setup srb and scsi status so this won't be fatal.
1034          * We do this so we can distinguish truly fatal failues
1035          * (srb status == 0x4) and off-line the device in that case.
1036          */
1037
1038         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1039            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1040                 vstor_packet->vm_srb.scsi_status = 0;
1041                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1042         }
1043
1044
1045         /* Copy over the status...etc */
1046         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1047         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1048         stor_pkt->vm_srb.sense_info_length =
1049         vstor_packet->vm_srb.sense_info_length;
1050
1051         if (vstor_packet->vm_srb.scsi_status != 0 ||
1052             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1053                 storvsc_log(device, STORVSC_LOGGING_WARN,
1054                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1055                         stor_pkt->vm_srb.cdb[0],
1056                         vstor_packet->vm_srb.scsi_status,
1057                         vstor_packet->vm_srb.srb_status);
1058
1059         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1060                 /* CHECK_CONDITION */
1061                 if (vstor_packet->vm_srb.srb_status &
1062                         SRB_STATUS_AUTOSENSE_VALID) {
1063                         /* autosense data available */
1064
1065                         storvsc_log(device, STORVSC_LOGGING_WARN,
1066                                 "stor pkt %p autosense data valid - len %d\n",
1067                                 request, vstor_packet->vm_srb.sense_info_length);
1068
1069                         memcpy(request->cmd->sense_buffer,
1070                                vstor_packet->vm_srb.sense_data,
1071                                vstor_packet->vm_srb.sense_info_length);
1072
1073                 }
1074         }
1075
1076         stor_pkt->vm_srb.data_transfer_length =
1077         vstor_packet->vm_srb.data_transfer_length;
1078
1079         storvsc_command_completion(request, stor_device);
1080
1081         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1082                 stor_device->drain_notify)
1083                 wake_up(&stor_device->waiting_to_drain);
1084
1085
1086 }
1087
1088 static void storvsc_on_receive(struct storvsc_device *stor_device,
1089                              struct vstor_packet *vstor_packet,
1090                              struct storvsc_cmd_request *request)
1091 {
1092         struct storvsc_scan_work *work;
1093
1094         switch (vstor_packet->operation) {
1095         case VSTOR_OPERATION_COMPLETE_IO:
1096                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1097                 break;
1098
1099         case VSTOR_OPERATION_REMOVE_DEVICE:
1100         case VSTOR_OPERATION_ENUMERATE_BUS:
1101                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1102                 if (!work)
1103                         return;
1104
1105                 INIT_WORK(&work->work, storvsc_host_scan);
1106                 work->host = stor_device->host;
1107                 schedule_work(&work->work);
1108                 break;
1109
1110         case VSTOR_OPERATION_FCHBA_DATA:
1111                 cache_wwn(stor_device, vstor_packet);
1112 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1113                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1114                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1115 #endif
1116                 break;
1117         default:
1118                 break;
1119         }
1120 }
1121
1122 static void storvsc_on_channel_callback(void *context)
1123 {
1124         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1125         struct hv_device *device;
1126         struct storvsc_device *stor_device;
1127         u32 bytes_recvd;
1128         u64 request_id;
1129         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1130         struct storvsc_cmd_request *request;
1131         int ret;
1132
1133         if (channel->primary_channel != NULL)
1134                 device = channel->primary_channel->device_obj;
1135         else
1136                 device = channel->device_obj;
1137
1138         stor_device = get_in_stor_device(device);
1139         if (!stor_device)
1140                 return;
1141
1142         do {
1143                 ret = vmbus_recvpacket(channel, packet,
1144                                        ALIGN((sizeof(struct vstor_packet) -
1145                                              vmscsi_size_delta), 8),
1146                                        &bytes_recvd, &request_id);
1147                 if (ret == 0 && bytes_recvd > 0) {
1148
1149                         request = (struct storvsc_cmd_request *)
1150                                         (unsigned long)request_id;
1151
1152                         if ((request == &stor_device->init_request) ||
1153                             (request == &stor_device->reset_request)) {
1154
1155                                 memcpy(&request->vstor_packet, packet,
1156                                        (sizeof(struct vstor_packet) -
1157                                         vmscsi_size_delta));
1158                                 complete(&request->wait_event);
1159                         } else {
1160                                 storvsc_on_receive(stor_device,
1161                                                 (struct vstor_packet *)packet,
1162                                                 request);
1163                         }
1164                 } else {
1165                         break;
1166                 }
1167         } while (1);
1168
1169         return;
1170 }
1171
1172 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1173                                   bool is_fc)
1174 {
1175         struct vmstorage_channel_properties props;
1176         int ret;
1177
1178         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1179
1180         ret = vmbus_open(device->channel,
1181                          ring_size,
1182                          ring_size,
1183                          (void *)&props,
1184                          sizeof(struct vmstorage_channel_properties),
1185                          storvsc_on_channel_callback, device->channel);
1186
1187         if (ret != 0)
1188                 return ret;
1189
1190         ret = storvsc_channel_init(device, is_fc);
1191
1192         return ret;
1193 }
1194
1195 static int storvsc_dev_remove(struct hv_device *device)
1196 {
1197         struct storvsc_device *stor_device;
1198         unsigned long flags;
1199
1200         stor_device = hv_get_drvdata(device);
1201
1202         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1203         stor_device->destroy = true;
1204         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1205
1206         /*
1207          * At this point, all outbound traffic should be disable. We
1208          * only allow inbound traffic (responses) to proceed so that
1209          * outstanding requests can be completed.
1210          */
1211
1212         storvsc_wait_to_drain(stor_device);
1213
1214         /*
1215          * Since we have already drained, we don't need to busy wait
1216          * as was done in final_release_stor_device()
1217          * Note that we cannot set the ext pointer to NULL until
1218          * we have drained - to drain the outgoing packets, we need to
1219          * allow incoming packets.
1220          */
1221         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1222         hv_set_drvdata(device, NULL);
1223         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1224
1225         /* Close the channel */
1226         vmbus_close(device->channel);
1227
1228         kfree(stor_device);
1229         return 0;
1230 }
1231
1232 static int storvsc_do_io(struct hv_device *device,
1233                          struct storvsc_cmd_request *request)
1234 {
1235         struct storvsc_device *stor_device;
1236         struct vstor_packet *vstor_packet;
1237         struct vmbus_channel *outgoing_channel;
1238         int ret = 0;
1239
1240         vstor_packet = &request->vstor_packet;
1241         stor_device = get_out_stor_device(device);
1242
1243         if (!stor_device)
1244                 return -ENODEV;
1245
1246
1247         request->device  = device;
1248         /*
1249          * Select an an appropriate channel to send the request out.
1250          */
1251
1252         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1253
1254
1255         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1256
1257         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1258                                         vmscsi_size_delta);
1259
1260
1261         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1262
1263
1264         vstor_packet->vm_srb.data_transfer_length =
1265         request->payload->range.len;
1266
1267         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1268
1269         if (request->payload->range.len) {
1270
1271                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1272                                 request->payload, request->payload_sz,
1273                                 vstor_packet,
1274                                 (sizeof(struct vstor_packet) -
1275                                 vmscsi_size_delta),
1276                                 (unsigned long)request);
1277         } else {
1278                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1279                                (sizeof(struct vstor_packet) -
1280                                 vmscsi_size_delta),
1281                                (unsigned long)request,
1282                                VM_PKT_DATA_INBAND,
1283                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1284         }
1285
1286         if (ret != 0)
1287                 return ret;
1288
1289         atomic_inc(&stor_device->num_outstanding_req);
1290
1291         return ret;
1292 }
1293
1294 static int storvsc_device_alloc(struct scsi_device *sdevice)
1295 {
1296         /*
1297          * Set blist flag to permit the reading of the VPD pages even when
1298          * the target may claim SPC-2 compliance. MSFT targets currently
1299          * claim SPC-2 compliance while they implement post SPC-2 features.
1300          * With this flag we can correctly handle WRITE_SAME_16 issues.
1301          *
1302          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1303          * still supports REPORT LUN.
1304          */
1305         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1306
1307         return 0;
1308 }
1309
1310 static int storvsc_device_configure(struct scsi_device *sdevice)
1311 {
1312
1313         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1314
1315         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1316
1317         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1318
1319         /* Ensure there are no gaps in presented sgls */
1320         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1321
1322         sdevice->no_write_same = 1;
1323
1324         /*
1325          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1326          * if the device is a MSFT virtual device.  If the host is
1327          * WIN10 or newer, allow write_same.
1328          */
1329         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1330                 switch (vmstor_proto_version) {
1331                 case VMSTOR_PROTO_VERSION_WIN8:
1332                 case VMSTOR_PROTO_VERSION_WIN8_1:
1333                         sdevice->scsi_level = SCSI_SPC_3;
1334                         break;
1335                 }
1336
1337                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1338                         sdevice->no_write_same = 0;
1339         }
1340
1341         return 0;
1342 }
1343
1344 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1345                            sector_t capacity, int *info)
1346 {
1347         sector_t nsect = capacity;
1348         sector_t cylinders = nsect;
1349         int heads, sectors_pt;
1350
1351         /*
1352          * We are making up these values; let us keep it simple.
1353          */
1354         heads = 0xff;
1355         sectors_pt = 0x3f;      /* Sectors per track */
1356         sector_div(cylinders, heads * sectors_pt);
1357         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1358                 cylinders = 0xffff;
1359
1360         info[0] = heads;
1361         info[1] = sectors_pt;
1362         info[2] = (int)cylinders;
1363
1364         return 0;
1365 }
1366
1367 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1368 {
1369         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1370         struct hv_device *device = host_dev->dev;
1371
1372         struct storvsc_device *stor_device;
1373         struct storvsc_cmd_request *request;
1374         struct vstor_packet *vstor_packet;
1375         int ret, t;
1376
1377
1378         stor_device = get_out_stor_device(device);
1379         if (!stor_device)
1380                 return FAILED;
1381
1382         request = &stor_device->reset_request;
1383         vstor_packet = &request->vstor_packet;
1384
1385         init_completion(&request->wait_event);
1386
1387         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1388         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1389         vstor_packet->vm_srb.path_id = stor_device->path_id;
1390
1391         ret = vmbus_sendpacket(device->channel, vstor_packet,
1392                                (sizeof(struct vstor_packet) -
1393                                 vmscsi_size_delta),
1394                                (unsigned long)&stor_device->reset_request,
1395                                VM_PKT_DATA_INBAND,
1396                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1397         if (ret != 0)
1398                 return FAILED;
1399
1400         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1401         if (t == 0)
1402                 return TIMEOUT_ERROR;
1403
1404
1405         /*
1406          * At this point, all outstanding requests in the adapter
1407          * should have been flushed out and return to us
1408          * There is a potential race here where the host may be in
1409          * the process of responding when we return from here.
1410          * Just wait for all in-transit packets to be accounted for
1411          * before we return from here.
1412          */
1413         storvsc_wait_to_drain(stor_device);
1414
1415         return SUCCESS;
1416 }
1417
1418 /*
1419  * The host guarantees to respond to each command, although I/O latencies might
1420  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1421  * chance to perform EH.
1422  */
1423 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1424 {
1425         return BLK_EH_RESET_TIMER;
1426 }
1427
1428 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1429 {
1430         bool allowed = true;
1431         u8 scsi_op = scmnd->cmnd[0];
1432
1433         switch (scsi_op) {
1434         /* the host does not handle WRITE_SAME, log accident usage */
1435         case WRITE_SAME:
1436         /*
1437          * smartd sends this command and the host does not handle
1438          * this. So, don't send it.
1439          */
1440         case SET_WINDOW:
1441                 scmnd->result = ILLEGAL_REQUEST << 16;
1442                 allowed = false;
1443                 break;
1444         default:
1445                 break;
1446         }
1447         return allowed;
1448 }
1449
1450 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1451 {
1452         int ret;
1453         struct hv_host_device *host_dev = shost_priv(host);
1454         struct hv_device *dev = host_dev->dev;
1455         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1456         int i;
1457         struct scatterlist *sgl;
1458         unsigned int sg_count = 0;
1459         struct vmscsi_request *vm_srb;
1460         struct scatterlist *cur_sgl;
1461         struct vmbus_packet_mpb_array  *payload;
1462         u32 payload_sz;
1463         u32 length;
1464
1465         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1466                 /*
1467                  * On legacy hosts filter unimplemented commands.
1468                  * Future hosts are expected to correctly handle
1469                  * unsupported commands. Furthermore, it is
1470                  * possible that some of the currently
1471                  * unsupported commands maybe supported in
1472                  * future versions of the host.
1473                  */
1474                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1475                         scmnd->scsi_done(scmnd);
1476                         return 0;
1477                 }
1478         }
1479
1480         /* Setup the cmd request */
1481         cmd_request->cmd = scmnd;
1482
1483         vm_srb = &cmd_request->vstor_packet.vm_srb;
1484         vm_srb->win8_extension.time_out_value = 60;
1485
1486         vm_srb->win8_extension.srb_flags |=
1487                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1488
1489         if (scmnd->device->tagged_supported) {
1490                 vm_srb->win8_extension.srb_flags |=
1491                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1492                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1493                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1494         }
1495
1496         /* Build the SRB */
1497         switch (scmnd->sc_data_direction) {
1498         case DMA_TO_DEVICE:
1499                 vm_srb->data_in = WRITE_TYPE;
1500                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1501                 break;
1502         case DMA_FROM_DEVICE:
1503                 vm_srb->data_in = READ_TYPE;
1504                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1505                 break;
1506         case DMA_NONE:
1507                 vm_srb->data_in = UNKNOWN_TYPE;
1508                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1509                 break;
1510         default:
1511                 /*
1512                  * This is DMA_BIDIRECTIONAL or something else we are never
1513                  * supposed to see here.
1514                  */
1515                 WARN(1, "Unexpected data direction: %d\n",
1516                      scmnd->sc_data_direction);
1517                 return -EINVAL;
1518         }
1519
1520
1521         vm_srb->port_number = host_dev->port;
1522         vm_srb->path_id = scmnd->device->channel;
1523         vm_srb->target_id = scmnd->device->id;
1524         vm_srb->lun = scmnd->device->lun;
1525
1526         vm_srb->cdb_length = scmnd->cmd_len;
1527
1528         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1529
1530         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1531         sg_count = scsi_sg_count(scmnd);
1532
1533         length = scsi_bufflen(scmnd);
1534         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1535         payload_sz = sizeof(cmd_request->mpb);
1536
1537         if (sg_count) {
1538                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1539
1540                         payload_sz = (sg_count * sizeof(void *) +
1541                                       sizeof(struct vmbus_packet_mpb_array));
1542                         payload = kmalloc(payload_sz, GFP_ATOMIC);
1543                         if (!payload)
1544                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1545                 }
1546
1547                 payload->range.len = length;
1548                 payload->range.offset = sgl[0].offset;
1549
1550                 cur_sgl = sgl;
1551                 for (i = 0; i < sg_count; i++) {
1552                         payload->range.pfn_array[i] =
1553                                 page_to_pfn(sg_page((cur_sgl)));
1554                         cur_sgl = sg_next(cur_sgl);
1555                 }
1556
1557         } else if (scsi_sglist(scmnd)) {
1558                 payload->range.len = length;
1559                 payload->range.offset =
1560                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1561                 payload->range.pfn_array[0] =
1562                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1563         }
1564
1565         cmd_request->payload = payload;
1566         cmd_request->payload_sz = payload_sz;
1567
1568         /* Invokes the vsc to start an IO */
1569         ret = storvsc_do_io(dev, cmd_request);
1570
1571         if (ret == -EAGAIN) {
1572                 if (payload_sz > sizeof(cmd_request->mpb))
1573                         kfree(payload);
1574                 /* no more space */
1575                 return SCSI_MLQUEUE_DEVICE_BUSY;
1576         }
1577
1578         return 0;
1579 }
1580
1581 static struct scsi_host_template scsi_driver = {
1582         .module =               THIS_MODULE,
1583         .name =                 "storvsc_host_t",
1584         .cmd_size =             sizeof(struct storvsc_cmd_request),
1585         .bios_param =           storvsc_get_chs,
1586         .queuecommand =         storvsc_queuecommand,
1587         .eh_host_reset_handler =        storvsc_host_reset_handler,
1588         .proc_name =            "storvsc_host",
1589         .eh_timed_out =         storvsc_eh_timed_out,
1590         .slave_alloc =          storvsc_device_alloc,
1591         .slave_configure =      storvsc_device_configure,
1592         .cmd_per_lun =          2048,
1593         .this_id =              -1,
1594         .use_clustering =       ENABLE_CLUSTERING,
1595         /* Make sure we dont get a sg segment crosses a page boundary */
1596         .dma_boundary =         PAGE_SIZE-1,
1597         .no_write_same =        1,
1598 };
1599
1600 enum {
1601         SCSI_GUID,
1602         IDE_GUID,
1603         SFC_GUID,
1604 };
1605
1606 static const struct hv_vmbus_device_id id_table[] = {
1607         /* SCSI guid */
1608         { HV_SCSI_GUID,
1609           .driver_data = SCSI_GUID
1610         },
1611         /* IDE guid */
1612         { HV_IDE_GUID,
1613           .driver_data = IDE_GUID
1614         },
1615         /* Fibre Channel GUID */
1616         {
1617           HV_SYNTHFC_GUID,
1618           .driver_data = SFC_GUID
1619         },
1620         { },
1621 };
1622
1623 MODULE_DEVICE_TABLE(vmbus, id_table);
1624
1625 static int storvsc_probe(struct hv_device *device,
1626                         const struct hv_vmbus_device_id *dev_id)
1627 {
1628         int ret;
1629         int num_cpus = num_online_cpus();
1630         struct Scsi_Host *host;
1631         struct hv_host_device *host_dev;
1632         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1633         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1634         int target = 0;
1635         struct storvsc_device *stor_device;
1636         int max_luns_per_target;
1637         int max_targets;
1638         int max_channels;
1639         int max_sub_channels = 0;
1640
1641         /*
1642          * Based on the windows host we are running on,
1643          * set state to properly communicate with the host.
1644          */
1645
1646         if (vmbus_proto_version < VERSION_WIN8) {
1647                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1648                 max_targets = STORVSC_IDE_MAX_TARGETS;
1649                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1650         } else {
1651                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1652                 max_targets = STORVSC_MAX_TARGETS;
1653                 max_channels = STORVSC_MAX_CHANNELS;
1654                 /*
1655                  * On Windows8 and above, we support sub-channels for storage.
1656                  * The number of sub-channels offerred is based on the number of
1657                  * VCPUs in the guest.
1658                  */
1659                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1660         }
1661
1662         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1663                                  (max_sub_channels + 1));
1664
1665         host = scsi_host_alloc(&scsi_driver,
1666                                sizeof(struct hv_host_device));
1667         if (!host)
1668                 return -ENOMEM;
1669
1670         host_dev = shost_priv(host);
1671         memset(host_dev, 0, sizeof(struct hv_host_device));
1672
1673         host_dev->port = host->host_no;
1674         host_dev->dev = device;
1675
1676
1677         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1678         if (!stor_device) {
1679                 ret = -ENOMEM;
1680                 goto err_out0;
1681         }
1682
1683         stor_device->destroy = false;
1684         stor_device->open_sub_channel = false;
1685         init_waitqueue_head(&stor_device->waiting_to_drain);
1686         stor_device->device = device;
1687         stor_device->host = host;
1688         hv_set_drvdata(device, stor_device);
1689
1690         stor_device->port_number = host->host_no;
1691         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1692         if (ret)
1693                 goto err_out1;
1694
1695         host_dev->path = stor_device->path_id;
1696         host_dev->target = stor_device->target_id;
1697
1698         switch (dev_id->driver_data) {
1699         case SFC_GUID:
1700                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1701                 host->max_id = STORVSC_FC_MAX_TARGETS;
1702                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1703 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1704                 host->transportt = fc_transport_template;
1705 #endif
1706                 break;
1707
1708         case SCSI_GUID:
1709                 host->max_lun = max_luns_per_target;
1710                 host->max_id = max_targets;
1711                 host->max_channel = max_channels - 1;
1712                 break;
1713
1714         default:
1715                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1716                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1717                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1718                 break;
1719         }
1720         /* max cmd length */
1721         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1722
1723         /*
1724          * set the table size based on the info we got
1725          * from the host.
1726          */
1727         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1728
1729         /* Register the HBA and start the scsi bus scan */
1730         ret = scsi_add_host(host, &device->device);
1731         if (ret != 0)
1732                 goto err_out2;
1733
1734         if (!dev_is_ide) {
1735                 scsi_scan_host(host);
1736         } else {
1737                 target = (device->dev_instance.b[5] << 8 |
1738                          device->dev_instance.b[4]);
1739                 ret = scsi_add_device(host, 0, target, 0);
1740                 if (ret) {
1741                         scsi_remove_host(host);
1742                         goto err_out2;
1743                 }
1744         }
1745 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1746         if (host->transportt == fc_transport_template) {
1747                 fc_host_node_name(host) = stor_device->node_name;
1748                 fc_host_port_name(host) = stor_device->port_name;
1749         }
1750 #endif
1751         return 0;
1752
1753 err_out2:
1754         /*
1755          * Once we have connected with the host, we would need to
1756          * to invoke storvsc_dev_remove() to rollback this state and
1757          * this call also frees up the stor_device; hence the jump around
1758          * err_out1 label.
1759          */
1760         storvsc_dev_remove(device);
1761         goto err_out0;
1762
1763 err_out1:
1764         kfree(stor_device);
1765
1766 err_out0:
1767         scsi_host_put(host);
1768         return ret;
1769 }
1770
1771 static int storvsc_remove(struct hv_device *dev)
1772 {
1773         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1774         struct Scsi_Host *host = stor_device->host;
1775
1776 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1777         if (host->transportt == fc_transport_template)
1778                 fc_remove_host(host);
1779 #endif
1780         scsi_remove_host(host);
1781         storvsc_dev_remove(dev);
1782         scsi_host_put(host);
1783
1784         return 0;
1785 }
1786
1787 static struct hv_driver storvsc_drv = {
1788         .name = KBUILD_MODNAME,
1789         .id_table = id_table,
1790         .probe = storvsc_probe,
1791         .remove = storvsc_remove,
1792 };
1793
1794 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1795 static struct fc_function_template fc_transport_functions = {
1796         .show_host_node_name = 1,
1797         .show_host_port_name = 1,
1798 };
1799 #endif
1800
1801 static int __init storvsc_drv_init(void)
1802 {
1803         int ret;
1804
1805         /*
1806          * Divide the ring buffer data size (which is 1 page less
1807          * than the ring buffer size since that page is reserved for
1808          * the ring buffer indices) by the max request size (which is
1809          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1810          */
1811         max_outstanding_req_per_channel =
1812                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1813                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1814                 sizeof(struct vstor_packet) + sizeof(u64) -
1815                 vmscsi_size_delta,
1816                 sizeof(u64)));
1817
1818 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1819         fc_transport_template = fc_attach_transport(&fc_transport_functions);
1820         if (!fc_transport_template)
1821                 return -ENODEV;
1822
1823         /*
1824          * Install Hyper-V specific timeout handler.
1825          */
1826         fc_transport_template->eh_timed_out = storvsc_eh_timed_out;
1827 #endif
1828
1829         ret = vmbus_driver_register(&storvsc_drv);
1830
1831 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1832         if (ret)
1833                 fc_release_transport(fc_transport_template);
1834 #endif
1835
1836         return ret;
1837 }
1838
1839 static void __exit storvsc_drv_exit(void)
1840 {
1841         vmbus_driver_unregister(&storvsc_drv);
1842 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1843         fc_release_transport(fc_transport_template);
1844 #endif
1845 }
1846
1847 MODULE_LICENSE("GPL");
1848 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1849 module_init(storvsc_drv_init);
1850 module_exit(storvsc_drv_exit);