drivers/scsi/storvsc_drv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   5  * Authors:
   6  *   Haiyang Zhang <haiyangz@microsoft.com>
   7  *   Hank Janssen  <hjanssen@microsoft.com>
   8  *   K. Y. Srinivasan <kys@microsoft.com>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/wait.h>
  13 #include <linux/sched.h>
  14 #include <linux/completion.h>
  15 #include <linux/string.h>
  16 #include <linux/mm.h>
  17 #include <linux/delay.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/module.h>
  21 #include <linux/device.h>
  22 #include <linux/hyperv.h>
  23 #include <linux/blkdev.h>
  24 #include <scsi/scsi.h>
  25 #include <scsi/scsi_cmnd.h>
  26 #include <scsi/scsi_host.h>
  27 #include <scsi/scsi_device.h>
  28 #include <scsi/scsi_tcq.h>
  29 #include <scsi/scsi_eh.h>
  30 #include <scsi/scsi_devinfo.h>
  31 #include <scsi/scsi_dbg.h>
  32 #include <scsi/scsi_transport_fc.h>
  33 #include <scsi/scsi_transport.h>
  34
  35 /*
  36  * All wire protocol details (storage protocol between the guest and the host)
  37  * are consolidated here.
  38  *
  39  * Begin protocol definitions.
  40  */
  41
  42 /*
  43  * Version history:
  44  * V1 Beta: 0.1
  45  * V1 RC < 2008/1/31: 1.0
  46  * V1 RC > 2008/1/31:  2.0
  47  * Win7: 4.2
  48  * Win8: 5.1
  49  * Win8.1: 6.0
  50  * Win10: 6.2
  51  */
  52
  53 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  54                                                 (((MINOR_) & 0xff)))
  55
  56 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  57 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  58 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  59 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  60 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  61
  62 /*  Packet structure describing virtual storage requests. */
  63 enum vstor_packet_operation {
  64         VSTOR_OPERATION_COMPLETE_IO             = 1,
  65         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  66         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  67         VSTOR_OPERATION_RESET_LUN               = 4,
  68         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  69         VSTOR_OPERATION_RESET_BUS               = 6,
  70         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  71         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  72         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  73         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  74         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  75         VSTOR_OPERATION_FCHBA_DATA              = 12,
  76         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  77         VSTOR_OPERATION_MAXIMUM                 = 13
  78 };
  79
  80 /*
  81  * WWN packet for Fibre Channel HBA
  82  */
  83
  84 struct hv_fc_wwn_packet {
  85         u8      primary_active;
  86         u8      reserved1[3];
  87         u8      primary_port_wwn[8];
  88         u8      primary_node_wwn[8];
  89         u8      secondary_port_wwn[8];
  90         u8      secondary_node_wwn[8];
  91 };
  92
  93
  94
  95 /*
  96  * SRB Flag Bits
  97  */
  98
  99 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 100 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 101 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 102 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 103 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 104 #define SRB_FLAGS_DATA_IN                       0x00000040
 105 #define SRB_FLAGS_DATA_OUT                      0x00000080
 106 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 107 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 108 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 109 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 110 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 111
 112 /*
 113  * This flag indicates the request is part of the workflow for processing a D3.
 114  */
 115 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 116 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 117 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 118 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 119 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 120 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 121 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 122 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 123 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 124 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 125 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 126
 127 #define SP_UNTAGGED                     ((unsigned char) ~0)
 128 #define SRB_SIMPLE_TAG_REQUEST          0x20
 129
 130 /*
 131  * Platform neutral description of a scsi request -
 132  * this remains the same across the write regardless of 32/64 bit
 133  * note: it's patterned off the SCSI_PASS_THROUGH structure
 134  */
 135 #define STORVSC_MAX_CMD_LEN                     0x10
 136
 137 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 138 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 139
 140 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 141 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 142
 143 /*
 144  * Sense buffer size changed in win8; have a run-time
 145  * variable to track the size we should use.  This value will
 146  * likely change during protocol negotiation but it is valid
 147  * to start by assuming pre-Win8.
 148  */
 149 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 150
 151 /*
 152  * The storage protocol version is determined during the
 153  * initial exchange with the host.  It will indicate which
 154  * storage functionality is available in the host.
 155 */
 156 static int vmstor_proto_version;
 157
 158 #define STORVSC_LOGGING_NONE    0
 159 #define STORVSC_LOGGING_ERROR   1
 160 #define STORVSC_LOGGING_WARN    2
 161
 162 static int logging_level = STORVSC_LOGGING_ERROR;
 163 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 164 MODULE_PARM_DESC(logging_level,
 165         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 166
 167 static inline bool do_logging(int level)
 168 {
 169         return logging_level >= level;
 170 }
 171
 172 #define storvsc_log(dev, level, fmt, ...)                       \
 173 do {                                                            \
 174         if (do_logging(level))                                  \
 175                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 176 } while (0)
 177
 178 struct vmscsi_win8_extension {
 179         /*
 180          * The following were added in Windows 8
 181          */
 182         u16 reserve;
 183         u8  queue_tag;
 184         u8  queue_action;
 185         u32 srb_flags;
 186         u32 time_out_value;
 187         u32 queue_sort_ey;
 188 } __packed;
 189
 190 struct vmscsi_request {
 191         u16 length;
 192         u8 srb_status;
 193         u8 scsi_status;
 194
 195         u8  port_number;
 196         u8  path_id;
 197         u8  target_id;
 198         u8  lun;
 199
 200         u8  cdb_length;
 201         u8  sense_info_length;
 202         u8  data_in;
 203         u8  reserved;
 204
 205         u32 data_transfer_length;
 206
 207         union {
 208                 u8 cdb[STORVSC_MAX_CMD_LEN];
 209                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 210                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 211         };
 212         /*
 213          * The following was added in win8.
 214          */
 215         struct vmscsi_win8_extension win8_extension;
 216
 217 } __attribute((packed));
 218
 219 /*
 220  * The list of storage protocols in order of preference.
 221  */
 222 struct vmstor_protocol {
 223         int protocol_version;
 224         int sense_buffer_size;
 225         int vmscsi_size_delta;
 226 };
 227
 228
 229 static const struct vmstor_protocol vmstor_protocols[] = {
 230         {
 231                 VMSTOR_PROTO_VERSION_WIN10,
 232                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 233                 0
 234         },
 235         {
 236                 VMSTOR_PROTO_VERSION_WIN8_1,
 237                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 238                 0
 239         },
 240         {
 241                 VMSTOR_PROTO_VERSION_WIN8,
 242                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 243                 0
 244         },
 245         {
 246                 VMSTOR_PROTO_VERSION_WIN7,
 247                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 248                 sizeof(struct vmscsi_win8_extension),
 249         },
 250         {
 251                 VMSTOR_PROTO_VERSION_WIN6,
 252                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 253                 sizeof(struct vmscsi_win8_extension),
 254         }
 255 };
 256
 257
 258 /*
 259  * This structure is sent during the initialization phase to get the different
 260  * properties of the channel.
 261  */
 262
 263 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 264
 265 struct vmstorage_channel_properties {
 266         u32 reserved;
 267         u16 max_channel_cnt;
 268         u16 reserved1;
 269
 270         u32 flags;
 271         u32   max_transfer_bytes;
 272
 273         u64  reserved2;
 274 } __packed;
 275
 276 /*  This structure is sent during the storage protocol negotiations. */
 277 struct vmstorage_protocol_version {
 278         /* Major (MSW) and minor (LSW) version numbers. */
 279         u16 major_minor;
 280
 281         /*
 282          * Revision number is auto-incremented whenever this file is changed
 283          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 284          * definitely indicate incompatibility--but it does indicate mismatched
 285          * builds.
 286          * This is only used on the windows side. Just set it to 0.
 287          */
 288         u16 revision;
 289 } __packed;
 290
 291 /* Channel Property Flags */
 292 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 293 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 294
 295 struct vstor_packet {
 296         /* Requested operation type */
 297         enum vstor_packet_operation operation;
 298
 299         /*  Flags - see below for values */
 300         u32 flags;
 301
 302         /* Status of the request returned from the server side. */
 303         u32 status;
 304
 305         /* Data payload area */
 306         union {
 307                 /*
 308                  * Structure used to forward SCSI commands from the
 309                  * client to the server.
 310                  */
 311                 struct vmscsi_request vm_srb;
 312
 313                 /* Structure used to query channel properties. */
 314                 struct vmstorage_channel_properties storage_channel_properties;
 315
 316                 /* Used during version negotiations. */
 317                 struct vmstorage_protocol_version version;
 318
 319                 /* Fibre channel address packet */
 320                 struct hv_fc_wwn_packet wwn_packet;
 321
 322                 /* Number of sub-channels to create */
 323                 u16 sub_channel_count;
 324
 325                 /* This will be the maximum of the union members */
 326                 u8  buffer[0x34];
 327         };
 328 } __packed;
 329
 330 /*
 331  * Packet Flags:
 332  *
 333  * This flag indicates that the server should send back a completion for this
 334  * packet.
 335  */
 336
 337 #define REQUEST_COMPLETION_FLAG 0x1
 338
 339 /* Matches Windows-end */
 340 enum storvsc_request_type {
 341         WRITE_TYPE = 0,
 342         READ_TYPE,
 343         UNKNOWN_TYPE,
 344 };
 345
 346 /*
 347  * SRB status codes and masks. In the 8-bit field, the two high order bits
 348  * are flags, while the remaining 6 bits are an integer status code.  The
 349  * definitions here include only the subset of the integer status codes that
 350  * are tested for in this driver.
 351  */
 352 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 353 #define SRB_STATUS_QUEUE_FROZEN         0x40
 354
 355 /* SRB status integer codes */
 356 #define SRB_STATUS_SUCCESS              0x01
 357 #define SRB_STATUS_ABORTED              0x02
 358 #define SRB_STATUS_ERROR                0x04
 359 #define SRB_STATUS_INVALID_REQUEST      0x06
 360 #define SRB_STATUS_DATA_OVERRUN         0x12
 361 #define SRB_STATUS_INVALID_LUN          0x20
 362
 363 #define SRB_STATUS(status) \
 364         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 365 /*
 366  * This is the end of Protocol specific defines.
 367  */
 368
 369 static int storvsc_ringbuffer_size = (128 * 1024);
 370 static u32 max_outstanding_req_per_channel;
 371 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 372
 373 static int storvsc_vcpus_per_sub_channel = 4;
 374 static unsigned int storvsc_max_hw_queues;
 375
 376 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 377 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 378
 379 module_param(storvsc_max_hw_queues, uint, 0644);
 380 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
 381
 382 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 383 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 384
 385 static int ring_avail_percent_lowater = 10;
 386 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 387 MODULE_PARM_DESC(ring_avail_percent_lowater,
 388                 "Select a channel if available ring size > this in percent");
 389
 390 /*
 391  * Timeout in seconds for all devices managed by this driver.
 392  */
 393 static int storvsc_timeout = 180;
 394
 395 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 396 static struct scsi_transport_template *fc_transport_template;
 397 #endif
 398
 399 static struct scsi_host_template scsi_driver;
 400 static void storvsc_on_channel_callback(void *context);
 401
 402 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 403 #define STORVSC_MAX_TARGETS                             2
 404 #define STORVSC_MAX_CHANNELS                            8
 405
 406 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 407 #define STORVSC_FC_MAX_TARGETS                          128
 408 #define STORVSC_FC_MAX_CHANNELS                         8
 409
 410 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 411 #define STORVSC_IDE_MAX_TARGETS                         1
 412 #define STORVSC_IDE_MAX_CHANNELS                        1
 413
 414 /*
 415  * Upper bound on the size of a storvsc packet. vmscsi_size_delta is not
 416  * included in the calculation because it is set after STORVSC_MAX_PKT_SIZE
 417  * is used in storvsc_connect_to_vsp
 418  */
 419 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
 420                               sizeof(struct vstor_packet))
 421
 422 struct storvsc_cmd_request {
 423         struct scsi_cmnd *cmd;
 424
 425         struct hv_device *device;
 426
 427         /* Synchronize the request/response if needed */
 428         struct completion wait_event;
 429
 430         struct vmbus_channel_packet_multipage_buffer mpb;
 431         struct vmbus_packet_mpb_array *payload;
 432         u32 payload_sz;
 433
 434         struct vstor_packet vstor_packet;
 435 };
 436
 437
 438 /* A storvsc device is a device object that contains a vmbus channel */
 439 struct storvsc_device {
 440         struct hv_device *device;
 441
 442         bool     destroy;
 443         bool     drain_notify;
 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          * The size of the vmscsi_request has changed in win8. The
 460          * additional size is because of new elements added to the
 461          * structure. These elements are valid only when we are talking
 462          * to a win8 host.
 463          * Track the correction to size we need to apply. This value
 464          * will likely change during protocol negotiation but it is
 465          * valid to start by assuming pre-Win8.
 466          */
 467         int vmscsi_size_delta;
 468
 469         /*
 470          * Max I/O, the device can support.
 471          */
 472         u32   max_transfer_bytes;
 473         /*
 474          * Number of sub-channels we will open.
 475          */
 476         u16 num_sc;
 477         struct vmbus_channel **stor_chns;
 478         /*
 479          * Mask of CPUs bound to subchannels.
 480          */
 481         struct cpumask alloced_cpus;
 482         /*
 483          * Serializes modifications of stor_chns[] from storvsc_do_io()
 484          * and storvsc_change_target_cpu().
 485          */
 486         spinlock_t lock;
 487         /* Used for vsc/vsp channel reset process */
 488         struct storvsc_cmd_request init_request;
 489         struct storvsc_cmd_request reset_request;
 490         /*
 491          * Currently active port and node names for FC devices.
 492          */
 493         u64 node_name;
 494         u64 port_name;
 495 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 496         struct fc_rport *rport;
 497 #endif
 498 };
 499
 500 struct hv_host_device {
 501         struct hv_device *dev;
 502         unsigned int port;
 503         unsigned char path;
 504         unsigned char target;
 505         struct workqueue_struct *handle_error_wq;
 506         struct work_struct host_scan_work;
 507         struct Scsi_Host *host;
 508 };
 509
 510 struct storvsc_scan_work {
 511         struct work_struct work;
 512         struct Scsi_Host *host;
 513         u8 lun;
 514         u8 tgt_id;
 515 };
 516
 517 static void storvsc_device_scan(struct work_struct *work)
 518 {
 519         struct storvsc_scan_work *wrk;
 520         struct scsi_device *sdev;
 521
 522         wrk = container_of(work, struct storvsc_scan_work, work);
 523
 524         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 525         if (!sdev)
 526                 goto done;
 527         scsi_rescan_device(&sdev->sdev_gendev);
 528         scsi_device_put(sdev);
 529
 530 done:
 531         kfree(wrk);
 532 }
 533
 534 static void storvsc_host_scan(struct work_struct *work)
 535 {
 536         struct Scsi_Host *host;
 537         struct scsi_device *sdev;
 538         struct hv_host_device *host_device =
 539                 container_of(work, struct hv_host_device, host_scan_work);
 540
 541         host = host_device->host;
 542         /*
 543          * Before scanning the host, first check to see if any of the
 544          * currrently known devices have been hot removed. We issue a
 545          * "unit ready" command against all currently known devices.
 546          * This I/O will result in an error for devices that have been
 547          * removed. As part of handling the I/O error, we remove the device.
 548          *
 549          * When a LUN is added or removed, the host sends us a signal to
 550          * scan the host. Thus we are forced to discover the LUNs that
 551          * may have been removed this way.
 552          */
 553         mutex_lock(&host->scan_mutex);
 554         shost_for_each_device(sdev, host)
 555                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 556         mutex_unlock(&host->scan_mutex);
 557         /*
 558          * Now scan the host to discover LUNs that may have been added.
 559          */
 560         scsi_scan_host(host);
 561 }
 562
 563 static void storvsc_remove_lun(struct work_struct *work)
 564 {
 565         struct storvsc_scan_work *wrk;
 566         struct scsi_device *sdev;
 567
 568         wrk = container_of(work, struct storvsc_scan_work, work);
 569         if (!scsi_host_get(wrk->host))
 570                 goto done;
 571
 572         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 573
 574         if (sdev) {
 575                 scsi_remove_device(sdev);
 576                 scsi_device_put(sdev);
 577         }
 578         scsi_host_put(wrk->host);
 579
 580 done:
 581         kfree(wrk);
 582 }
 583
 584
 585 /*
 586  * We can get incoming messages from the host that are not in response to
 587  * messages that we have sent out. An example of this would be messages
 588  * received by the guest to notify dynamic addition/removal of LUNs. To
 589  * deal with potential race conditions where the driver may be in the
 590  * midst of being unloaded when we might receive an unsolicited message
 591  * from the host, we have implemented a mechanism to gurantee sequential
 592  * consistency:
 593  *
 594  * 1) Once the device is marked as being destroyed, we will fail all
 595  *    outgoing messages.
 596  * 2) We permit incoming messages when the device is being destroyed,
 597  *    only to properly account for messages already sent out.
 598  */
 599
 600 static inline struct storvsc_device *get_out_stor_device(
 601                                         struct hv_device *device)
 602 {
 603         struct storvsc_device *stor_device;
 604
 605         stor_device = hv_get_drvdata(device);
 606
 607         if (stor_device && stor_device->destroy)
 608                 stor_device = NULL;
 609
 610         return stor_device;
 611 }
 612
 613
 614 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 615 {
 616         dev->drain_notify = true;
 617         wait_event(dev->waiting_to_drain,
 618                    atomic_read(&dev->num_outstanding_req) == 0);
 619         dev->drain_notify = false;
 620 }
 621
 622 static inline struct storvsc_device *get_in_stor_device(
 623                                         struct hv_device *device)
 624 {
 625         struct storvsc_device *stor_device;
 626
 627         stor_device = hv_get_drvdata(device);
 628
 629         if (!stor_device)
 630                 goto get_in_err;
 631
 632         /*
 633          * If the device is being destroyed; allow incoming
 634          * traffic only to cleanup outstanding requests.
 635          */
 636
 637         if (stor_device->destroy  &&
 638                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 639                 stor_device = NULL;
 640
 641 get_in_err:
 642         return stor_device;
 643
 644 }
 645
 646 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 647                                       u32 new)
 648 {
 649         struct storvsc_device *stor_device;
 650         struct vmbus_channel *cur_chn;
 651         bool old_is_alloced = false;
 652         struct hv_device *device;
 653         unsigned long flags;
 654         int cpu;
 655
 656         device = channel->primary_channel ?
 657                         channel->primary_channel->device_obj
 658                                 : channel->device_obj;
 659         stor_device = get_out_stor_device(device);
 660         if (!stor_device)
 661                 return;
 662
 663         /* See storvsc_do_io() -> get_og_chn(). */
 664         spin_lock_irqsave(&stor_device->lock, flags);
 665
 666         /*
 667          * Determines if the storvsc device has other channels assigned to
 668          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 669          * array.
 670          */
 671         if (device->channel != channel && device->channel->target_cpu == old) {
 672                 cur_chn = device->channel;
 673                 old_is_alloced = true;
 674                 goto old_is_alloced;
 675         }
 676         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 677                 if (cur_chn == channel)
 678                         continue;
 679                 if (cur_chn->target_cpu == old) {
 680                         old_is_alloced = true;
 681                         goto old_is_alloced;
 682                 }
 683         }
 684
 685 old_is_alloced:
 686         if (old_is_alloced)
 687                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 688         else
 689                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 690
 691         /* "Flush" the stor_chns array. */
 692         for_each_possible_cpu(cpu) {
 693                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 694                                         cpu, &stor_device->alloced_cpus))
 695                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 696         }
 697
 698         WRITE_ONCE(stor_device->stor_chns[new], channel);
 699         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 700
 701         spin_unlock_irqrestore(&stor_device->lock, flags);
 702 }
 703
 704 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 705 {
 706         struct storvsc_cmd_request *request =
 707                 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
 708
 709         if (rqst_addr == VMBUS_RQST_INIT)
 710                 return VMBUS_RQST_INIT;
 711         if (rqst_addr == VMBUS_RQST_RESET)
 712                 return VMBUS_RQST_RESET;
 713
 714         /*
 715          * Cannot return an ID of 0, which is reserved for an unsolicited
 716          * message from Hyper-V.
 717          */
 718         return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
 719 }
 720
 721 static void handle_sc_creation(struct vmbus_channel *new_sc)
 722 {
 723         struct hv_device *device = new_sc->primary_channel->device_obj;
 724         struct device *dev = &device->device;
 725         struct storvsc_device *stor_device;
 726         struct vmstorage_channel_properties props;
 727         int ret;
 728
 729         stor_device = get_out_stor_device(device);
 730         if (!stor_device)
 731                 return;
 732
 733         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 734         new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
 735
 736         new_sc->next_request_id_callback = storvsc_next_request_id;
 737
 738         ret = vmbus_open(new_sc,
 739                          storvsc_ringbuffer_size,
 740                          storvsc_ringbuffer_size,
 741                          (void *)&props,
 742                          sizeof(struct vmstorage_channel_properties),
 743                          storvsc_on_channel_callback, new_sc);
 744
 745         /* In case vmbus_open() fails, we don't use the sub-channel. */
 746         if (ret != 0) {
 747                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 748                 return;
 749         }
 750
 751         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 752
 753         /* Add the sub-channel to the array of available channels. */
 754         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 755         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 756 }
 757
 758 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 759 {
 760         struct device *dev = &device->device;
 761         struct storvsc_device *stor_device;
 762         int num_sc;
 763         struct storvsc_cmd_request *request;
 764         struct vstor_packet *vstor_packet;
 765         int ret, t;
 766
 767         /*
 768          * If the number of CPUs is artificially restricted, such as
 769          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 770          * sub-channels >= the number of CPUs. These sub-channels
 771          * should not be created. The primary channel is already created
 772          * and assigned to one CPU, so check against # CPUs - 1.
 773          */
 774         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 775         if (!num_sc)
 776                 return;
 777
 778         stor_device = get_out_stor_device(device);
 779         if (!stor_device)
 780                 return;
 781
 782         stor_device->num_sc = num_sc;
 783         request = &stor_device->init_request;
 784         vstor_packet = &request->vstor_packet;
 785
 786         /*
 787          * Establish a handler for dealing with subchannels.
 788          */
 789         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 790
 791         /*
 792          * Request the host to create sub-channels.
 793          */
 794         memset(request, 0, sizeof(struct storvsc_cmd_request));
 795         init_completion(&request->wait_event);
 796         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 797         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 798         vstor_packet->sub_channel_count = num_sc;
 799
 800         ret = vmbus_sendpacket(device->channel, vstor_packet,
 801                                (sizeof(struct vstor_packet) -
 802                                stor_device->vmscsi_size_delta),
 803                                VMBUS_RQST_INIT,
 804                                VM_PKT_DATA_INBAND,
 805                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 806
 807         if (ret != 0) {
 808                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 809                 return;
 810         }
 811
 812         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 813         if (t == 0) {
 814                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 815                 return;
 816         }
 817
 818         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 819             vstor_packet->status != 0) {
 820                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 821                         vstor_packet->operation, vstor_packet->status);
 822                 return;
 823         }
 824
 825         /*
 826          * We need to do nothing here, because vmbus_process_offer()
 827          * invokes channel->sc_creation_callback, which will open and use
 828          * the sub-channel(s).
 829          */
 830 }
 831
 832 static void cache_wwn(struct storvsc_device *stor_device,
 833                       struct vstor_packet *vstor_packet)
 834 {
 835         /*
 836          * Cache the currently active port and node ww names.
 837          */
 838         if (vstor_packet->wwn_packet.primary_active) {
 839                 stor_device->node_name =
 840                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 841                 stor_device->port_name =
 842                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 843         } else {
 844                 stor_device->node_name =
 845                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 846                 stor_device->port_name =
 847                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 848         }
 849 }
 850
 851
 852 static int storvsc_execute_vstor_op(struct hv_device *device,
 853                                     struct storvsc_cmd_request *request,
 854                                     bool status_check)
 855 {
 856         struct storvsc_device *stor_device;
 857         struct vstor_packet *vstor_packet;
 858         int ret, t;
 859
 860         stor_device = get_out_stor_device(device);
 861         if (!stor_device)
 862                 return -ENODEV;
 863
 864         vstor_packet = &request->vstor_packet;
 865
 866         init_completion(&request->wait_event);
 867         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 868
 869         ret = vmbus_sendpacket(device->channel, vstor_packet,
 870                                (sizeof(struct vstor_packet) -
 871                                stor_device->vmscsi_size_delta),
 872                                VMBUS_RQST_INIT,
 873                                VM_PKT_DATA_INBAND,
 874                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 875         if (ret != 0)
 876                 return ret;
 877
 878         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 879         if (t == 0)
 880                 return -ETIMEDOUT;
 881
 882         if (!status_check)
 883                 return ret;
 884
 885         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 886             vstor_packet->status != 0)
 887                 return -EINVAL;
 888
 889         return ret;
 890 }
 891
 892 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 893 {
 894         struct storvsc_device *stor_device;
 895         struct storvsc_cmd_request *request;
 896         struct vstor_packet *vstor_packet;
 897         int ret, i;
 898         int max_chns;
 899         bool process_sub_channels = false;
 900
 901         stor_device = get_out_stor_device(device);
 902         if (!stor_device)
 903                 return -ENODEV;
 904
 905         request = &stor_device->init_request;
 906         vstor_packet = &request->vstor_packet;
 907
 908         /*
 909          * Now, initiate the vsc/vsp initialization protocol on the open
 910          * channel
 911          */
 912         memset(request, 0, sizeof(struct storvsc_cmd_request));
 913         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 914         ret = storvsc_execute_vstor_op(device, request, true);
 915         if (ret)
 916                 return ret;
 917         /*
 918          * Query host supported protocol version.
 919          */
 920
 921         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 922                 /* reuse the packet for version range supported */
 923                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 924                 vstor_packet->operation =
 925                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 926
 927                 vstor_packet->version.major_minor =
 928                         vmstor_protocols[i].protocol_version;
 929
 930                 /*
 931                  * The revision number is only used in Windows; set it to 0.
 932                  */
 933                 vstor_packet->version.revision = 0;
 934                 ret = storvsc_execute_vstor_op(device, request, false);
 935                 if (ret != 0)
 936                         return ret;
 937
 938                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 939                         return -EINVAL;
 940
 941                 if (vstor_packet->status == 0) {
 942                         vmstor_proto_version =
 943                                 vmstor_protocols[i].protocol_version;
 944
 945                         sense_buffer_size =
 946                                 vmstor_protocols[i].sense_buffer_size;
 947
 948                         stor_device->vmscsi_size_delta =
 949                                 vmstor_protocols[i].vmscsi_size_delta;
 950
 951                         break;
 952                 }
 953         }
 954
 955         if (vstor_packet->status != 0)
 956                 return -EINVAL;
 957
 958
 959         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 960         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 961         ret = storvsc_execute_vstor_op(device, request, true);
 962         if (ret != 0)
 963                 return ret;
 964
 965         /*
 966          * Check to see if multi-channel support is there.
 967          * Hosts that implement protocol version of 5.1 and above
 968          * support multi-channel.
 969          */
 970         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 971
 972         /*
 973          * Allocate state to manage the sub-channels.
 974          * We allocate an array based on the numbers of possible CPUs
 975          * (Hyper-V does not support cpu online/offline).
 976          * This Array will be sparseley populated with unique
 977          * channels - primary + sub-channels.
 978          * We will however populate all the slots to evenly distribute
 979          * the load.
 980          */
 981         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 982                                          GFP_KERNEL);
 983         if (stor_device->stor_chns == NULL)
 984                 return -ENOMEM;
 985
 986         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 987
 988         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 989         cpumask_set_cpu(device->channel->target_cpu,
 990                         &stor_device->alloced_cpus);
 991
 992         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 993                 if (vstor_packet->storage_channel_properties.flags &
 994                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 995                         process_sub_channels = true;
 996         }
 997         stor_device->max_transfer_bytes =
 998                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 999
1000         if (!is_fc)
1001                 goto done;
1002
1003         /*
1004          * For FC devices retrieve FC HBA data.
1005          */
1006         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1007         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
1008         ret = storvsc_execute_vstor_op(device, request, true);
1009         if (ret != 0)
1010                 return ret;
1011
1012         /*
1013          * Cache the currently active port and node ww names.
1014          */
1015         cache_wwn(stor_device, vstor_packet);
1016
1017 done:
1018
1019         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1020         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
1021         ret = storvsc_execute_vstor_op(device, request, true);
1022         if (ret != 0)
1023                 return ret;
1024
1025         if (process_sub_channels)
1026                 handle_multichannel_storage(device, max_chns);
1027
1028         return ret;
1029 }
1030
1031 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1032                                 struct scsi_cmnd *scmnd,
1033                                 struct Scsi_Host *host,
1034                                 u8 asc, u8 ascq)
1035 {
1036         struct storvsc_scan_work *wrk;
1037         void (*process_err_fn)(struct work_struct *work);
1038         struct hv_host_device *host_dev = shost_priv(host);
1039
1040         switch (SRB_STATUS(vm_srb->srb_status)) {
1041         case SRB_STATUS_ERROR:
1042         case SRB_STATUS_ABORTED:
1043         case SRB_STATUS_INVALID_REQUEST:
1044                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
1045                         /* Check for capacity change */
1046                         if ((asc == 0x2a) && (ascq == 0x9)) {
1047                                 process_err_fn = storvsc_device_scan;
1048                                 /* Retry the I/O that triggered this. */
1049                                 set_host_byte(scmnd, DID_REQUEUE);
1050                                 goto do_work;
1051                         }
1052
1053                         /*
1054                          * Otherwise, let upper layer deal with the
1055                          * error when sense message is present
1056                          */
1057                         return;
1058                 }
1059
1060                 /*
1061                  * If there is an error; offline the device since all
1062                  * error recovery strategies would have already been
1063                  * deployed on the host side. However, if the command
1064                  * were a pass-through command deal with it appropriately.
1065                  */
1066                 switch (scmnd->cmnd[0]) {
1067                 case ATA_16:
1068                 case ATA_12:
1069                         set_host_byte(scmnd, DID_PASSTHROUGH);
1070                         break;
1071                 /*
1072                  * On some Hyper-V hosts TEST_UNIT_READY command can
1073                  * return SRB_STATUS_ERROR. Let the upper level code
1074                  * deal with it based on the sense information.
1075                  */
1076                 case TEST_UNIT_READY:
1077                         break;
1078                 default:
1079                         set_host_byte(scmnd, DID_ERROR);
1080                 }
1081                 return;
1082
1083         case SRB_STATUS_INVALID_LUN:
1084                 set_host_byte(scmnd, DID_NO_CONNECT);
1085                 process_err_fn = storvsc_remove_lun;
1086                 goto do_work;
1087
1088         }
1089         return;
1090
1091 do_work:
1092         /*
1093          * We need to schedule work to process this error; schedule it.
1094          */
1095         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1096         if (!wrk) {
1097                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1098                 return;
1099         }
1100
1101         wrk->host = host;
1102         wrk->lun = vm_srb->lun;
1103         wrk->tgt_id = vm_srb->target_id;
1104         INIT_WORK(&wrk->work, process_err_fn);
1105         queue_work(host_dev->handle_error_wq, &wrk->work);
1106 }
1107
1108
1109 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1110                                        struct storvsc_device *stor_dev)
1111 {
1112         struct scsi_cmnd *scmnd = cmd_request->cmd;
1113         struct scsi_sense_hdr sense_hdr;
1114         struct vmscsi_request *vm_srb;
1115         u32 data_transfer_length;
1116         struct Scsi_Host *host;
1117         u32 payload_sz = cmd_request->payload_sz;
1118         void *payload = cmd_request->payload;
1119         bool sense_ok;
1120
1121         host = stor_dev->host;
1122
1123         vm_srb = &cmd_request->vstor_packet.vm_srb;
1124         data_transfer_length = vm_srb->data_transfer_length;
1125
1126         scmnd->result = vm_srb->scsi_status;
1127
1128         if (scmnd->result) {
1129                 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1130                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1131
1132                 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1133                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1134                                              &sense_hdr);
1135         }
1136
1137         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1138                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1139                                          sense_hdr.ascq);
1140                 /*
1141                  * The Windows driver set data_transfer_length on
1142                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1143                  * is untouched.  In these cases we set it to 0.
1144                  */
1145                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1146                         data_transfer_length = 0;
1147         }
1148
1149         /* Validate data_transfer_length (from Hyper-V) */
1150         if (data_transfer_length > cmd_request->payload->range.len)
1151                 data_transfer_length = cmd_request->payload->range.len;
1152
1153         scsi_set_resid(scmnd,
1154                 cmd_request->payload->range.len - data_transfer_length);
1155
1156         scmnd->scsi_done(scmnd);
1157
1158         if (payload_sz >
1159                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1160                 kfree(payload);
1161 }
1162
1163 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1164                                   struct vstor_packet *vstor_packet,
1165                                   struct storvsc_cmd_request *request)
1166 {
1167         struct vstor_packet *stor_pkt;
1168         struct hv_device *device = stor_device->device;
1169
1170         stor_pkt = &request->vstor_packet;
1171
1172         /*
1173          * The current SCSI handling on the host side does
1174          * not correctly handle:
1175          * INQUIRY command with page code parameter set to 0x80
1176          * MODE_SENSE command with cmd[2] == 0x1c
1177          *
1178          * Setup srb and scsi status so this won't be fatal.
1179          * We do this so we can distinguish truly fatal failues
1180          * (srb status == 0x4) and off-line the device in that case.
1181          */
1182
1183         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1184            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1185                 vstor_packet->vm_srb.scsi_status = 0;
1186                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1187         }
1188
1189         /* Copy over the status...etc */
1190         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1191         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1192
1193         /*
1194          * Copy over the sense_info_length, but limit to the known max
1195          * size if Hyper-V returns a bad value.
1196          */
1197         stor_pkt->vm_srb.sense_info_length = min_t(u8, sense_buffer_size,
1198                 vstor_packet->vm_srb.sense_info_length);
1199
1200         if (vstor_packet->vm_srb.scsi_status != 0 ||
1201             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1202
1203                 /*
1204                  * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1205                  * return errors when detecting devices using TEST_UNIT_READY,
1206                  * and logging these as errors produces unhelpful noise.
1207                  */
1208                 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1209                         STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1210
1211                 storvsc_log(device, loglevel,
1212                         "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1213                         scsi_cmd_to_rq(request->cmd)->tag,
1214                         stor_pkt->vm_srb.cdb[0],
1215                         vstor_packet->vm_srb.scsi_status,
1216                         vstor_packet->vm_srb.srb_status,
1217                         vstor_packet->status);
1218         }
1219
1220         if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1221             (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1222                 memcpy(request->cmd->sense_buffer,
1223                        vstor_packet->vm_srb.sense_data,
1224                        stor_pkt->vm_srb.sense_info_length);
1225
1226         stor_pkt->vm_srb.data_transfer_length =
1227                 vstor_packet->vm_srb.data_transfer_length;
1228
1229         storvsc_command_completion(request, stor_device);
1230
1231         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1232                 stor_device->drain_notify)
1233                 wake_up(&stor_device->waiting_to_drain);
1234 }
1235
1236 static void storvsc_on_receive(struct storvsc_device *stor_device,
1237                              struct vstor_packet *vstor_packet,
1238                              struct storvsc_cmd_request *request)
1239 {
1240         struct hv_host_device *host_dev;
1241         switch (vstor_packet->operation) {
1242         case VSTOR_OPERATION_COMPLETE_IO:
1243                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1244                 break;
1245
1246         case VSTOR_OPERATION_REMOVE_DEVICE:
1247         case VSTOR_OPERATION_ENUMERATE_BUS:
1248                 host_dev = shost_priv(stor_device->host);
1249                 queue_work(
1250                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1251                 break;
1252
1253         case VSTOR_OPERATION_FCHBA_DATA:
1254                 cache_wwn(stor_device, vstor_packet);
1255 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1256                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1257                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1258 #endif
1259                 break;
1260         default:
1261                 break;
1262         }
1263 }
1264
1265 static void storvsc_on_channel_callback(void *context)
1266 {
1267         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1268         const struct vmpacket_descriptor *desc;
1269         struct hv_device *device;
1270         struct storvsc_device *stor_device;
1271         struct Scsi_Host *shost;
1272
1273         if (channel->primary_channel != NULL)
1274                 device = channel->primary_channel->device_obj;
1275         else
1276                 device = channel->device_obj;
1277
1278         stor_device = get_in_stor_device(device);
1279         if (!stor_device)
1280                 return;
1281
1282         shost = stor_device->host;
1283
1284         foreach_vmbus_pkt(desc, channel) {
1285                 struct vstor_packet *packet = hv_pkt_data(desc);
1286                 struct storvsc_cmd_request *request = NULL;
1287                 u32 pktlen = hv_pkt_datalen(desc);
1288                 u64 rqst_id = desc->trans_id;
1289                 u32 minlen = rqst_id ? sizeof(struct vstor_packet) -
1290                         stor_device->vmscsi_size_delta : sizeof(enum vstor_packet_operation);
1291
1292                 if (pktlen < minlen) {
1293                         dev_err(&device->device,
1294                                 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1295                                 rqst_id, pktlen, minlen);
1296                         continue;
1297                 }
1298
1299                 if (rqst_id == VMBUS_RQST_INIT) {
1300                         request = &stor_device->init_request;
1301                 } else if (rqst_id == VMBUS_RQST_RESET) {
1302                         request = &stor_device->reset_request;
1303                 } else {
1304                         /* Hyper-V can send an unsolicited message with ID of 0 */
1305                         if (rqst_id == 0) {
1306                                 /*
1307                                  * storvsc_on_receive() looks at the vstor_packet in the message
1308                                  * from the ring buffer.
1309                                  *
1310                                  * - If the operation in the vstor_packet is COMPLETE_IO, then
1311                                  *   we call storvsc_on_io_completion(), and dereference the
1312                                  *   guest memory address.  Make sure we don't call
1313                                  *   storvsc_on_io_completion() with a guest memory address
1314                                  *   that is zero if Hyper-V were to construct and send such
1315                                  *   a bogus packet.
1316                                  *
1317                                  * - If the operation in the vstor_packet is FCHBA_DATA, then
1318                                  *   we call cache_wwn(), and access the data payload area of
1319                                  *   the packet (wwn_packet); however, there is no guarantee
1320                                  *   that the packet is big enough to contain such area.
1321                                  *   Future-proof the code by rejecting such a bogus packet.
1322                                  */
1323                                 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1324                                     packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1325                                         dev_err(&device->device, "Invalid packet with ID of 0\n");
1326                                         continue;
1327                                 }
1328                         } else {
1329                                 struct scsi_cmnd *scmnd;
1330
1331                                 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1332                                 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1333                                 if (scmnd == NULL) {
1334                                         dev_err(&device->device, "Incorrect transaction ID\n");
1335                                         continue;
1336                                 }
1337                                 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1338                         }
1339
1340                         storvsc_on_receive(stor_device, packet, request);
1341                         continue;
1342                 }
1343
1344                 memcpy(&request->vstor_packet, packet,
1345                        (sizeof(struct vstor_packet) - stor_device->vmscsi_size_delta));
1346                 complete(&request->wait_event);
1347         }
1348 }
1349
1350 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1351                                   bool is_fc)
1352 {
1353         struct vmstorage_channel_properties props;
1354         int ret;
1355
1356         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1357
1358         device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1359         device->channel->next_request_id_callback = storvsc_next_request_id;
1360
1361         ret = vmbus_open(device->channel,
1362                          ring_size,
1363                          ring_size,
1364                          (void *)&props,
1365                          sizeof(struct vmstorage_channel_properties),
1366                          storvsc_on_channel_callback, device->channel);
1367
1368         if (ret != 0)
1369                 return ret;
1370
1371         ret = storvsc_channel_init(device, is_fc);
1372
1373         return ret;
1374 }
1375
1376 static int storvsc_dev_remove(struct hv_device *device)
1377 {
1378         struct storvsc_device *stor_device;
1379
1380         stor_device = hv_get_drvdata(device);
1381
1382         stor_device->destroy = true;
1383
1384         /* Make sure flag is set before waiting */
1385         wmb();
1386
1387         /*
1388          * At this point, all outbound traffic should be disable. We
1389          * only allow inbound traffic (responses) to proceed so that
1390          * outstanding requests can be completed.
1391          */
1392
1393         storvsc_wait_to_drain(stor_device);
1394
1395         /*
1396          * Since we have already drained, we don't need to busy wait
1397          * as was done in final_release_stor_device()
1398          * Note that we cannot set the ext pointer to NULL until
1399          * we have drained - to drain the outgoing packets, we need to
1400          * allow incoming packets.
1401          */
1402         hv_set_drvdata(device, NULL);
1403
1404         /* Close the channel */
1405         vmbus_close(device->channel);
1406
1407         kfree(stor_device->stor_chns);
1408         kfree(stor_device);
1409         return 0;
1410 }
1411
1412 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1413                                         u16 q_num)
1414 {
1415         u16 slot = 0;
1416         u16 hash_qnum;
1417         const struct cpumask *node_mask;
1418         int num_channels, tgt_cpu;
1419
1420         if (stor_device->num_sc == 0) {
1421                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1422                 return stor_device->device->channel;
1423         }
1424
1425         /*
1426          * Our channel array is sparsley populated and we
1427          * initiated I/O on a processor/hw-q that does not
1428          * currently have a designated channel. Fix this.
1429          * The strategy is simple:
1430          * I. Ensure NUMA locality
1431          * II. Distribute evenly (best effort)
1432          */
1433
1434         node_mask = cpumask_of_node(cpu_to_node(q_num));
1435
1436         num_channels = 0;
1437         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1438                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1439                         num_channels++;
1440         }
1441         if (num_channels == 0) {
1442                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1443                 return stor_device->device->channel;
1444         }
1445
1446         hash_qnum = q_num;
1447         while (hash_qnum >= num_channels)
1448                 hash_qnum -= num_channels;
1449
1450         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1451                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1452                         continue;
1453                 if (slot == hash_qnum)
1454                         break;
1455                 slot++;
1456         }
1457
1458         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1459
1460         return stor_device->stor_chns[q_num];
1461 }
1462
1463
1464 static int storvsc_do_io(struct hv_device *device,
1465                          struct storvsc_cmd_request *request, u16 q_num)
1466 {
1467         struct storvsc_device *stor_device;
1468         struct vstor_packet *vstor_packet;
1469         struct vmbus_channel *outgoing_channel, *channel;
1470         unsigned long flags;
1471         int ret = 0;
1472         const struct cpumask *node_mask;
1473         int tgt_cpu;
1474
1475         vstor_packet = &request->vstor_packet;
1476         stor_device = get_out_stor_device(device);
1477
1478         if (!stor_device)
1479                 return -ENODEV;
1480
1481
1482         request->device  = device;
1483         /*
1484          * Select an appropriate channel to send the request out.
1485          */
1486         /* See storvsc_change_target_cpu(). */
1487         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1488         if (outgoing_channel != NULL) {
1489                 if (outgoing_channel->target_cpu == q_num) {
1490                         /*
1491                          * Ideally, we want to pick a different channel if
1492                          * available on the same NUMA node.
1493                          */
1494                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1495                         for_each_cpu_wrap(tgt_cpu,
1496                                  &stor_device->alloced_cpus, q_num + 1) {
1497                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1498                                         continue;
1499                                 if (tgt_cpu == q_num)
1500                                         continue;
1501                                 channel = READ_ONCE(
1502                                         stor_device->stor_chns[tgt_cpu]);
1503                                 if (channel == NULL)
1504                                         continue;
1505                                 if (hv_get_avail_to_write_percent(
1506                                                         &channel->outbound)
1507                                                 > ring_avail_percent_lowater) {
1508                                         outgoing_channel = channel;
1509                                         goto found_channel;
1510                                 }
1511                         }
1512
1513                         /*
1514                          * All the other channels on the same NUMA node are
1515                          * busy. Try to use the channel on the current CPU
1516                          */
1517                         if (hv_get_avail_to_write_percent(
1518                                                 &outgoing_channel->outbound)
1519                                         > ring_avail_percent_lowater)
1520                                 goto found_channel;
1521
1522                         /*
1523                          * If we reach here, all the channels on the current
1524                          * NUMA node are busy. Try to find a channel in
1525                          * other NUMA nodes
1526                          */
1527                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1528                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1529                                         continue;
1530                                 channel = READ_ONCE(
1531                                         stor_device->stor_chns[tgt_cpu]);
1532                                 if (channel == NULL)
1533                                         continue;
1534                                 if (hv_get_avail_to_write_percent(
1535                                                         &channel->outbound)
1536                                                 > ring_avail_percent_lowater) {
1537                                         outgoing_channel = channel;
1538                                         goto found_channel;
1539                                 }
1540                         }
1541                 }
1542         } else {
1543                 spin_lock_irqsave(&stor_device->lock, flags);
1544                 outgoing_channel = stor_device->stor_chns[q_num];
1545                 if (outgoing_channel != NULL) {
1546                         spin_unlock_irqrestore(&stor_device->lock, flags);
1547                         goto found_channel;
1548                 }
1549                 outgoing_channel = get_og_chn(stor_device, q_num);
1550                 spin_unlock_irqrestore(&stor_device->lock, flags);
1551         }
1552
1553 found_channel:
1554         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1555
1556         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1557                                         stor_device->vmscsi_size_delta);
1558
1559
1560         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1561
1562
1563         vstor_packet->vm_srb.data_transfer_length =
1564         request->payload->range.len;
1565
1566         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1567
1568         if (request->payload->range.len) {
1569
1570                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1571                                 request->payload, request->payload_sz,
1572                                 vstor_packet,
1573                                 (sizeof(struct vstor_packet) -
1574                                 stor_device->vmscsi_size_delta),
1575                                 (unsigned long)request);
1576         } else {
1577                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1578                                (sizeof(struct vstor_packet) -
1579                                 stor_device->vmscsi_size_delta),
1580                                (unsigned long)request,
1581                                VM_PKT_DATA_INBAND,
1582                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1583         }
1584
1585         if (ret != 0)
1586                 return ret;
1587
1588         atomic_inc(&stor_device->num_outstanding_req);
1589
1590         return ret;
1591 }
1592
1593 static int storvsc_device_alloc(struct scsi_device *sdevice)
1594 {
1595         /*
1596          * Set blist flag to permit the reading of the VPD pages even when
1597          * the target may claim SPC-2 compliance. MSFT targets currently
1598          * claim SPC-2 compliance while they implement post SPC-2 features.
1599          * With this flag we can correctly handle WRITE_SAME_16 issues.
1600          *
1601          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1602          * still supports REPORT LUN.
1603          */
1604         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1605
1606         return 0;
1607 }
1608
1609 static int storvsc_device_configure(struct scsi_device *sdevice)
1610 {
1611         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1612
1613         sdevice->no_write_same = 1;
1614
1615         /*
1616          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1617          * if the device is a MSFT virtual device.  If the host is
1618          * WIN10 or newer, allow write_same.
1619          */
1620         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1621                 switch (vmstor_proto_version) {
1622                 case VMSTOR_PROTO_VERSION_WIN8:
1623                 case VMSTOR_PROTO_VERSION_WIN8_1:
1624                         sdevice->scsi_level = SCSI_SPC_3;
1625                         break;
1626                 }
1627
1628                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1629                         sdevice->no_write_same = 0;
1630         }
1631
1632         return 0;
1633 }
1634
1635 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1636                            sector_t capacity, int *info)
1637 {
1638         sector_t nsect = capacity;
1639         sector_t cylinders = nsect;
1640         int heads, sectors_pt;
1641
1642         /*
1643          * We are making up these values; let us keep it simple.
1644          */
1645         heads = 0xff;
1646         sectors_pt = 0x3f;      /* Sectors per track */
1647         sector_div(cylinders, heads * sectors_pt);
1648         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1649                 cylinders = 0xffff;
1650
1651         info[0] = heads;
1652         info[1] = sectors_pt;
1653         info[2] = (int)cylinders;
1654
1655         return 0;
1656 }
1657
1658 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1659 {
1660         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1661         struct hv_device *device = host_dev->dev;
1662
1663         struct storvsc_device *stor_device;
1664         struct storvsc_cmd_request *request;
1665         struct vstor_packet *vstor_packet;
1666         int ret, t;
1667
1668         stor_device = get_out_stor_device(device);
1669         if (!stor_device)
1670                 return FAILED;
1671
1672         request = &stor_device->reset_request;
1673         vstor_packet = &request->vstor_packet;
1674         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1675
1676         init_completion(&request->wait_event);
1677
1678         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1679         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1680         vstor_packet->vm_srb.path_id = stor_device->path_id;
1681
1682         ret = vmbus_sendpacket(device->channel, vstor_packet,
1683                                (sizeof(struct vstor_packet) -
1684                                 stor_device->vmscsi_size_delta),
1685                                VMBUS_RQST_RESET,
1686                                VM_PKT_DATA_INBAND,
1687                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1688         if (ret != 0)
1689                 return FAILED;
1690
1691         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1692         if (t == 0)
1693                 return TIMEOUT_ERROR;
1694
1695
1696         /*
1697          * At this point, all outstanding requests in the adapter
1698          * should have been flushed out and return to us
1699          * There is a potential race here where the host may be in
1700          * the process of responding when we return from here.
1701          * Just wait for all in-transit packets to be accounted for
1702          * before we return from here.
1703          */
1704         storvsc_wait_to_drain(stor_device);
1705
1706         return SUCCESS;
1707 }
1708
1709 /*
1710  * The host guarantees to respond to each command, although I/O latencies might
1711  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1712  * chance to perform EH.
1713  */
1714 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1715 {
1716 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1717         if (scmnd->device->host->transportt == fc_transport_template)
1718                 return fc_eh_timed_out(scmnd);
1719 #endif
1720         return BLK_EH_RESET_TIMER;
1721 }
1722
1723 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1724 {
1725         bool allowed = true;
1726         u8 scsi_op = scmnd->cmnd[0];
1727
1728         switch (scsi_op) {
1729         /* the host does not handle WRITE_SAME, log accident usage */
1730         case WRITE_SAME:
1731         /*
1732          * smartd sends this command and the host does not handle
1733          * this. So, don't send it.
1734          */
1735         case SET_WINDOW:
1736                 set_host_byte(scmnd, DID_ERROR);
1737                 allowed = false;
1738                 break;
1739         default:
1740                 break;
1741         }
1742         return allowed;
1743 }
1744
1745 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1746 {
1747         int ret;
1748         struct hv_host_device *host_dev = shost_priv(host);
1749         struct hv_device *dev = host_dev->dev;
1750         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1751         int i;
1752         struct scatterlist *sgl;
1753         unsigned int sg_count;
1754         struct vmscsi_request *vm_srb;
1755         struct vmbus_packet_mpb_array  *payload;
1756         u32 payload_sz;
1757         u32 length;
1758
1759         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1760                 /*
1761                  * On legacy hosts filter unimplemented commands.
1762                  * Future hosts are expected to correctly handle
1763                  * unsupported commands. Furthermore, it is
1764                  * possible that some of the currently
1765                  * unsupported commands maybe supported in
1766                  * future versions of the host.
1767                  */
1768                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1769                         scmnd->scsi_done(scmnd);
1770                         return 0;
1771                 }
1772         }
1773
1774         /* Setup the cmd request */
1775         cmd_request->cmd = scmnd;
1776
1777         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1778         vm_srb = &cmd_request->vstor_packet.vm_srb;
1779         vm_srb->win8_extension.time_out_value = 60;
1780
1781         vm_srb->win8_extension.srb_flags |=
1782                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1783
1784         if (scmnd->device->tagged_supported) {
1785                 vm_srb->win8_extension.srb_flags |=
1786                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1787                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1788                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1789         }
1790
1791         /* Build the SRB */
1792         switch (scmnd->sc_data_direction) {
1793         case DMA_TO_DEVICE:
1794                 vm_srb->data_in = WRITE_TYPE;
1795                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1796                 break;
1797         case DMA_FROM_DEVICE:
1798                 vm_srb->data_in = READ_TYPE;
1799                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1800                 break;
1801         case DMA_NONE:
1802                 vm_srb->data_in = UNKNOWN_TYPE;
1803                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1804                 break;
1805         default:
1806                 /*
1807                  * This is DMA_BIDIRECTIONAL or something else we are never
1808                  * supposed to see here.
1809                  */
1810                 WARN(1, "Unexpected data direction: %d\n",
1811                      scmnd->sc_data_direction);
1812                 return -EINVAL;
1813         }
1814
1815
1816         vm_srb->port_number = host_dev->port;
1817         vm_srb->path_id = scmnd->device->channel;
1818         vm_srb->target_id = scmnd->device->id;
1819         vm_srb->lun = scmnd->device->lun;
1820
1821         vm_srb->cdb_length = scmnd->cmd_len;
1822
1823         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1824
1825         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1826         sg_count = scsi_sg_count(scmnd);
1827
1828         length = scsi_bufflen(scmnd);
1829         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1830         payload_sz = sizeof(cmd_request->mpb);
1831
1832         if (sg_count) {
1833                 unsigned int hvpgoff, hvpfns_to_add;
1834                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1835                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1836                 u64 hvpfn;
1837
1838                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1839
1840                         payload_sz = (hvpg_count * sizeof(u64) +
1841                                       sizeof(struct vmbus_packet_mpb_array));
1842                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1843                         if (!payload)
1844                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1845                 }
1846
1847                 payload->range.len = length;
1848                 payload->range.offset = offset_in_hvpg;
1849
1850
1851                 for (i = 0; sgl != NULL; sgl = sg_next(sgl)) {
1852                         /*
1853                          * Init values for the current sgl entry. hvpgoff
1854                          * and hvpfns_to_add are in units of Hyper-V size
1855                          * pages. Handling the PAGE_SIZE != HV_HYP_PAGE_SIZE
1856                          * case also handles values of sgl->offset that are
1857                          * larger than PAGE_SIZE. Such offsets are handled
1858                          * even on other than the first sgl entry, provided
1859                          * they are a multiple of PAGE_SIZE.
1860                          */
1861                         hvpgoff = HVPFN_DOWN(sgl->offset);
1862                         hvpfn = page_to_hvpfn(sg_page(sgl)) + hvpgoff;
1863                         hvpfns_to_add = HVPFN_UP(sgl->offset + sgl->length) -
1864                                                 hvpgoff;
1865
1866                         /*
1867                          * Fill the next portion of the PFN array with
1868                          * sequential Hyper-V PFNs for the continguous physical
1869                          * memory described by the sgl entry. The end of the
1870                          * last sgl should be reached at the same time that
1871                          * the PFN array is filled.
1872                          */
1873                         while (hvpfns_to_add--)
1874                                 payload->range.pfn_array[i++] = hvpfn++;
1875                 }
1876         }
1877
1878         cmd_request->payload = payload;
1879         cmd_request->payload_sz = payload_sz;
1880
1881         /* Invokes the vsc to start an IO */
1882         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1883         put_cpu();
1884
1885         if (ret == -EAGAIN) {
1886                 if (payload_sz > sizeof(cmd_request->mpb))
1887                         kfree(payload);
1888                 /* no more space */
1889                 return SCSI_MLQUEUE_DEVICE_BUSY;
1890         }
1891
1892         return 0;
1893 }
1894
1895 static struct scsi_host_template scsi_driver = {
1896         .module =               THIS_MODULE,
1897         .name =                 "storvsc_host_t",
1898         .cmd_size =             sizeof(struct storvsc_cmd_request),
1899         .bios_param =           storvsc_get_chs,
1900         .queuecommand =         storvsc_queuecommand,
1901         .eh_host_reset_handler =        storvsc_host_reset_handler,
1902         .proc_name =            "storvsc_host",
1903         .eh_timed_out =         storvsc_eh_timed_out,
1904         .slave_alloc =          storvsc_device_alloc,
1905         .slave_configure =      storvsc_device_configure,
1906         .cmd_per_lun =          2048,
1907         .this_id =              -1,
1908         /* Ensure there are no gaps in presented sgls */
1909         .virt_boundary_mask =   HV_HYP_PAGE_SIZE - 1,
1910         .no_write_same =        1,
1911         .track_queue_depth =    1,
1912         .change_queue_depth =   storvsc_change_queue_depth,
1913 };
1914
1915 enum {
1916         SCSI_GUID,
1917         IDE_GUID,
1918         SFC_GUID,
1919 };
1920
1921 static const struct hv_vmbus_device_id id_table[] = {
1922         /* SCSI guid */
1923         { HV_SCSI_GUID,
1924           .driver_data = SCSI_GUID
1925         },
1926         /* IDE guid */
1927         { HV_IDE_GUID,
1928           .driver_data = IDE_GUID
1929         },
1930         /* Fibre Channel GUID */
1931         {
1932           HV_SYNTHFC_GUID,
1933           .driver_data = SFC_GUID
1934         },
1935         { },
1936 };
1937
1938 MODULE_DEVICE_TABLE(vmbus, id_table);
1939
1940 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1941
1942 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1943 {
1944         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1945 }
1946
1947 static int storvsc_probe(struct hv_device *device,
1948                         const struct hv_vmbus_device_id *dev_id)
1949 {
1950         int ret;
1951         int num_cpus = num_online_cpus();
1952         int num_present_cpus = num_present_cpus();
1953         struct Scsi_Host *host;
1954         struct hv_host_device *host_dev;
1955         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1956         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1957         int target = 0;
1958         struct storvsc_device *stor_device;
1959         int max_luns_per_target;
1960         int max_targets;
1961         int max_channels;
1962         int max_sub_channels = 0;
1963         u32 max_xfer_bytes;
1964
1965         /*
1966          * Based on the windows host we are running on,
1967          * set state to properly communicate with the host.
1968          */
1969
1970         if (vmbus_proto_version < VERSION_WIN8) {
1971                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1972                 max_targets = STORVSC_IDE_MAX_TARGETS;
1973                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1974         } else {
1975                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1976                 max_targets = STORVSC_MAX_TARGETS;
1977                 max_channels = STORVSC_MAX_CHANNELS;
1978                 /*
1979                  * On Windows8 and above, we support sub-channels for storage
1980                  * on SCSI and FC controllers.
1981                  * The number of sub-channels offerred is based on the number of
1982                  * VCPUs in the guest.
1983                  */
1984                 if (!dev_is_ide)
1985                         max_sub_channels =
1986                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1987         }
1988
1989         scsi_driver.can_queue = max_outstanding_req_per_channel *
1990                                 (max_sub_channels + 1) *
1991                                 (100 - ring_avail_percent_lowater) / 100;
1992
1993         host = scsi_host_alloc(&scsi_driver,
1994                                sizeof(struct hv_host_device));
1995         if (!host)
1996                 return -ENOMEM;
1997
1998         host_dev = shost_priv(host);
1999         memset(host_dev, 0, sizeof(struct hv_host_device));
2000
2001         host_dev->port = host->host_no;
2002         host_dev->dev = device;
2003         host_dev->host = host;
2004
2005
2006         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
2007         if (!stor_device) {
2008                 ret = -ENOMEM;
2009                 goto err_out0;
2010         }
2011
2012         stor_device->destroy = false;
2013         init_waitqueue_head(&stor_device->waiting_to_drain);
2014         stor_device->device = device;
2015         stor_device->host = host;
2016         stor_device->vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
2017         spin_lock_init(&stor_device->lock);
2018         hv_set_drvdata(device, stor_device);
2019
2020         stor_device->port_number = host->host_no;
2021         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
2022         if (ret)
2023                 goto err_out1;
2024
2025         host_dev->path = stor_device->path_id;
2026         host_dev->target = stor_device->target_id;
2027
2028         switch (dev_id->driver_data) {
2029         case SFC_GUID:
2030                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
2031                 host->max_id = STORVSC_FC_MAX_TARGETS;
2032                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
2033 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2034                 host->transportt = fc_transport_template;
2035 #endif
2036                 break;
2037
2038         case SCSI_GUID:
2039                 host->max_lun = max_luns_per_target;
2040                 host->max_id = max_targets;
2041                 host->max_channel = max_channels - 1;
2042                 break;
2043
2044         default:
2045                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
2046                 host->max_id = STORVSC_IDE_MAX_TARGETS;
2047                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
2048                 break;
2049         }
2050         /* max cmd length */
2051         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
2052         /*
2053          * Any reasonable Hyper-V configuration should provide
2054          * max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
2055          * protecting it from any weird value.
2056          */
2057         max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
2058         /* max_hw_sectors_kb */
2059         host->max_sectors = max_xfer_bytes >> 9;
2060         /*
2061          * There are 2 requirements for Hyper-V storvsc sgl segments,
2062          * based on which the below calculation for max segments is
2063          * done:
2064          *
2065          * 1. Except for the first and last sgl segment, all sgl segments
2066          *    should be align to HV_HYP_PAGE_SIZE, that also means the
2067          *    maximum number of segments in a sgl can be calculated by
2068          *    dividing the total max transfer length by HV_HYP_PAGE_SIZE.
2069          *
2070          * 2. Except for the first and last, each entry in the SGL must
2071          *    have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2072          */
2073         host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2074         /*
2075          * For non-IDE disks, the host supports multiple channels.
2076          * Set the number of HW queues we are supporting.
2077          */
2078         if (!dev_is_ide) {
2079                 if (storvsc_max_hw_queues > num_present_cpus) {
2080                         storvsc_max_hw_queues = 0;
2081                         storvsc_log(device, STORVSC_LOGGING_WARN,
2082                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2083                 }
2084                 if (storvsc_max_hw_queues)
2085                         host->nr_hw_queues = storvsc_max_hw_queues;
2086                 else
2087                         host->nr_hw_queues = num_present_cpus;
2088         }
2089
2090         /*
2091          * Set the error handler work queue.
2092          */
2093         host_dev->handle_error_wq =
2094                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2095                                                 0,
2096                                                 host->host_no);
2097         if (!host_dev->handle_error_wq) {
2098                 ret = -ENOMEM;
2099                 goto err_out2;
2100         }
2101         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2102         /* Register the HBA and start the scsi bus scan */
2103         ret = scsi_add_host(host, &device->device);
2104         if (ret != 0)
2105                 goto err_out3;
2106
2107         if (!dev_is_ide) {
2108                 scsi_scan_host(host);
2109         } else {
2110                 target = (device->dev_instance.b[5] << 8 |
2111                          device->dev_instance.b[4]);
2112                 ret = scsi_add_device(host, 0, target, 0);
2113                 if (ret)
2114                         goto err_out4;
2115         }
2116 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2117         if (host->transportt == fc_transport_template) {
2118                 struct fc_rport_identifiers ids = {
2119                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2120                 };
2121
2122                 fc_host_node_name(host) = stor_device->node_name;
2123                 fc_host_port_name(host) = stor_device->port_name;
2124                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2125                 if (!stor_device->rport) {
2126                         ret = -ENOMEM;
2127                         goto err_out4;
2128                 }
2129         }
2130 #endif
2131         return 0;
2132
2133 err_out4:
2134         scsi_remove_host(host);
2135
2136 err_out3:
2137         destroy_workqueue(host_dev->handle_error_wq);
2138
2139 err_out2:
2140         /*
2141          * Once we have connected with the host, we would need to
2142          * to invoke storvsc_dev_remove() to rollback this state and
2143          * this call also frees up the stor_device; hence the jump around
2144          * err_out1 label.
2145          */
2146         storvsc_dev_remove(device);
2147         goto err_out0;
2148
2149 err_out1:
2150         kfree(stor_device->stor_chns);
2151         kfree(stor_device);
2152
2153 err_out0:
2154         scsi_host_put(host);
2155         return ret;
2156 }
2157
2158 /* Change a scsi target's queue depth */
2159 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2160 {
2161         if (queue_depth > scsi_driver.can_queue)
2162                 queue_depth = scsi_driver.can_queue;
2163
2164         return scsi_change_queue_depth(sdev, queue_depth);
2165 }
2166
2167 static int storvsc_remove(struct hv_device *dev)
2168 {
2169         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2170         struct Scsi_Host *host = stor_device->host;
2171         struct hv_host_device *host_dev = shost_priv(host);
2172
2173 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2174         if (host->transportt == fc_transport_template) {
2175                 fc_remote_port_delete(stor_device->rport);
2176                 fc_remove_host(host);
2177         }
2178 #endif
2179         destroy_workqueue(host_dev->handle_error_wq);
2180         scsi_remove_host(host);
2181         storvsc_dev_remove(dev);
2182         scsi_host_put(host);
2183
2184         return 0;
2185 }
2186
2187 static int storvsc_suspend(struct hv_device *hv_dev)
2188 {
2189         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2190         struct Scsi_Host *host = stor_device->host;
2191         struct hv_host_device *host_dev = shost_priv(host);
2192
2193         storvsc_wait_to_drain(stor_device);
2194
2195         drain_workqueue(host_dev->handle_error_wq);
2196
2197         vmbus_close(hv_dev->channel);
2198
2199         kfree(stor_device->stor_chns);
2200         stor_device->stor_chns = NULL;
2201
2202         cpumask_clear(&stor_device->alloced_cpus);
2203
2204         return 0;
2205 }
2206
2207 static int storvsc_resume(struct hv_device *hv_dev)
2208 {
2209         int ret;
2210
2211         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2212                                      hv_dev_is_fc(hv_dev));
2213         return ret;
2214 }
2215
2216 static struct hv_driver storvsc_drv = {
2217         .name = KBUILD_MODNAME,
2218         .id_table = id_table,
2219         .probe = storvsc_probe,
2220         .remove = storvsc_remove,
2221         .suspend = storvsc_suspend,
2222         .resume = storvsc_resume,
2223         .driver = {
2224                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2225         },
2226 };
2227
2228 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2229 static struct fc_function_template fc_transport_functions = {
2230         .show_host_node_name = 1,
2231         .show_host_port_name = 1,
2232 };
2233 #endif
2234
2235 static int __init storvsc_drv_init(void)
2236 {
2237         int ret;
2238
2239         /*
2240          * Divide the ring buffer data size (which is 1 page less
2241          * than the ring buffer size since that page is reserved for
2242          * the ring buffer indices) by the max request size (which is
2243          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2244          *
2245          * The computation underestimates max_outstanding_req_per_channel
2246          * for Win7 and older hosts because it does not take into account
2247          * the vmscsi_size_delta correction to the max request size.
2248          */
2249         max_outstanding_req_per_channel =
2250                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2251                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2252                 sizeof(struct vstor_packet) + sizeof(u64),
2253                 sizeof(u64)));
2254
2255 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2256         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2257         if (!fc_transport_template)
2258                 return -ENODEV;
2259 #endif
2260
2261         ret = vmbus_driver_register(&storvsc_drv);
2262
2263 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2264         if (ret)
2265                 fc_release_transport(fc_transport_template);
2266 #endif
2267
2268         return ret;
2269 }
2270
2271 static void __exit storvsc_drv_exit(void)
2272 {
2273         vmbus_driver_unregister(&storvsc_drv);
2274 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2275         fc_release_transport(fc_transport_template);
2276 #endif
2277 }
2278
2279 MODULE_LICENSE("GPL");
2280 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2281 module_init(storvsc_drv_init);
2282 module_exit(storvsc_drv_exit);