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 <linux/dma-mapping.h>
  25
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_cmnd.h>
  28 #include <scsi/scsi_host.h>
  29 #include <scsi/scsi_device.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_devinfo.h>
  33 #include <scsi/scsi_dbg.h>
  34 #include <scsi/scsi_transport_fc.h>
  35 #include <scsi/scsi_transport.h>
  36
  37 /*
  38  * All wire protocol details (storage protocol between the guest and the host)
  39  * are consolidated here.
  40  *
  41  * Begin protocol definitions.
  42  */
  43
  44 /*
  45  * Version history:
  46  * V1 Beta: 0.1
  47  * V1 RC < 2008/1/31: 1.0
  48  * V1 RC > 2008/1/31:  2.0
  49  * Win7: 4.2
  50  * Win8: 5.1
  51  * Win8.1: 6.0
  52  * Win10: 6.2
  53  */
  54
  55 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  56                                                 (((MINOR_) & 0xff)))
  57 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  58 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  59 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  60 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  61 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  62
  63 /* channel callback timeout in ms */
  64 #define CALLBACK_TIMEOUT               2
  65
  66 /*  Packet structure describing virtual storage requests. */
  67 enum vstor_packet_operation {
  68         VSTOR_OPERATION_COMPLETE_IO             = 1,
  69         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  70         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  71         VSTOR_OPERATION_RESET_LUN               = 4,
  72         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  73         VSTOR_OPERATION_RESET_BUS               = 6,
  74         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  75         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  76         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  77         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  78         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  79         VSTOR_OPERATION_FCHBA_DATA              = 12,
  80         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  81         VSTOR_OPERATION_MAXIMUM                 = 13
  82 };
  83
  84 /*
  85  * WWN packet for Fibre Channel HBA
  86  */
  87
  88 struct hv_fc_wwn_packet {
  89         u8      primary_active;
  90         u8      reserved1[3];
  91         u8      primary_port_wwn[8];
  92         u8      primary_node_wwn[8];
  93         u8      secondary_port_wwn[8];
  94         u8      secondary_node_wwn[8];
  95 };
  96
  97
  98
  99 /*
 100  * SRB Flag Bits
 101  */
 102
 103 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 104 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 105 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 106 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 107 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 108 #define SRB_FLAGS_DATA_IN                       0x00000040
 109 #define SRB_FLAGS_DATA_OUT                      0x00000080
 110 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 111 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 112 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 113 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 114 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 115
 116 /*
 117  * This flag indicates the request is part of the workflow for processing a D3.
 118  */
 119 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 120 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 121 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 122 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 123 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 124 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 125 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 126 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 127 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 128 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 129 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 130
 131 #define SP_UNTAGGED                     ((unsigned char) ~0)
 132 #define SRB_SIMPLE_TAG_REQUEST          0x20
 133
 134 /*
 135  * Platform neutral description of a scsi request -
 136  * this remains the same across the write regardless of 32/64 bit
 137  * note: it's patterned off the SCSI_PASS_THROUGH structure
 138  */
 139 #define STORVSC_MAX_CMD_LEN                     0x10
 140
 141 /* Sense buffer size is the same for all versions since Windows 8 */
 142 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 143 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 144
 145 /*
 146  * The storage protocol version is determined during the
 147  * initial exchange with the host.  It will indicate which
 148  * storage functionality is available in the host.
 149 */
 150 static int vmstor_proto_version;
 151
 152 #define STORVSC_LOGGING_NONE    0
 153 #define STORVSC_LOGGING_ERROR   1
 154 #define STORVSC_LOGGING_WARN    2
 155
 156 static int logging_level = STORVSC_LOGGING_ERROR;
 157 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 158 MODULE_PARM_DESC(logging_level,
 159         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 160
 161 static inline bool do_logging(int level)
 162 {
 163         return logging_level >= level;
 164 }
 165
 166 #define storvsc_log(dev, level, fmt, ...)                       \
 167 do {                                                            \
 168         if (do_logging(level))                                  \
 169                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 170 } while (0)
 171
 172 struct vmscsi_request {
 173         u16 length;
 174         u8 srb_status;
 175         u8 scsi_status;
 176
 177         u8  port_number;
 178         u8  path_id;
 179         u8  target_id;
 180         u8  lun;
 181
 182         u8  cdb_length;
 183         u8  sense_info_length;
 184         u8  data_in;
 185         u8  reserved;
 186
 187         u32 data_transfer_length;
 188
 189         union {
 190                 u8 cdb[STORVSC_MAX_CMD_LEN];
 191                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 192                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 193         };
 194         /*
 195          * The following was added in win8.
 196          */
 197         u16 reserve;
 198         u8  queue_tag;
 199         u8  queue_action;
 200         u32 srb_flags;
 201         u32 time_out_value;
 202         u32 queue_sort_ey;
 203
 204 } __attribute((packed));
 205
 206 /*
 207  * The list of windows version in order of preference.
 208  */
 209
 210 static const int protocol_version[] = {
 211                 VMSTOR_PROTO_VERSION_WIN10,
 212                 VMSTOR_PROTO_VERSION_WIN8_1,
 213                 VMSTOR_PROTO_VERSION_WIN8,
 214 };
 215
 216
 217 /*
 218  * This structure is sent during the initialization phase to get the different
 219  * properties of the channel.
 220  */
 221
 222 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 223
 224 struct vmstorage_channel_properties {
 225         u32 reserved;
 226         u16 max_channel_cnt;
 227         u16 reserved1;
 228
 229         u32 flags;
 230         u32   max_transfer_bytes;
 231
 232         u64  reserved2;
 233 } __packed;
 234
 235 /*  This structure is sent during the storage protocol negotiations. */
 236 struct vmstorage_protocol_version {
 237         /* Major (MSW) and minor (LSW) version numbers. */
 238         u16 major_minor;
 239
 240         /*
 241          * Revision number is auto-incremented whenever this file is changed
 242          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 243          * definitely indicate incompatibility--but it does indicate mismatched
 244          * builds.
 245          * This is only used on the windows side. Just set it to 0.
 246          */
 247         u16 revision;
 248 } __packed;
 249
 250 /* Channel Property Flags */
 251 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 252 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 253
 254 struct vstor_packet {
 255         /* Requested operation type */
 256         enum vstor_packet_operation operation;
 257
 258         /*  Flags - see below for values */
 259         u32 flags;
 260
 261         /* Status of the request returned from the server side. */
 262         u32 status;
 263
 264         /* Data payload area */
 265         union {
 266                 /*
 267                  * Structure used to forward SCSI commands from the
 268                  * client to the server.
 269                  */
 270                 struct vmscsi_request vm_srb;
 271
 272                 /* Structure used to query channel properties. */
 273                 struct vmstorage_channel_properties storage_channel_properties;
 274
 275                 /* Used during version negotiations. */
 276                 struct vmstorage_protocol_version version;
 277
 278                 /* Fibre channel address packet */
 279                 struct hv_fc_wwn_packet wwn_packet;
 280
 281                 /* Number of sub-channels to create */
 282                 u16 sub_channel_count;
 283
 284                 /* This will be the maximum of the union members */
 285                 u8  buffer[0x34];
 286         };
 287 } __packed;
 288
 289 /*
 290  * Packet Flags:
 291  *
 292  * This flag indicates that the server should send back a completion for this
 293  * packet.
 294  */
 295
 296 #define REQUEST_COMPLETION_FLAG 0x1
 297
 298 /* Matches Windows-end */
 299 enum storvsc_request_type {
 300         WRITE_TYPE = 0,
 301         READ_TYPE,
 302         UNKNOWN_TYPE,
 303 };
 304
 305 /*
 306  * SRB status codes and masks. In the 8-bit field, the two high order bits
 307  * are flags, while the remaining 6 bits are an integer status code.  The
 308  * definitions here include only the subset of the integer status codes that
 309  * are tested for in this driver.
 310  */
 311 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 312 #define SRB_STATUS_QUEUE_FROZEN         0x40
 313
 314 /* SRB status integer codes */
 315 #define SRB_STATUS_SUCCESS              0x01
 316 #define SRB_STATUS_ABORTED              0x02
 317 #define SRB_STATUS_ERROR                0x04
 318 #define SRB_STATUS_INVALID_REQUEST      0x06
 319 #define SRB_STATUS_DATA_OVERRUN         0x12
 320 #define SRB_STATUS_INVALID_LUN          0x20
 321 #define SRB_STATUS_INTERNAL_ERROR       0x30
 322
 323 #define SRB_STATUS(status) \
 324         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 325 /*
 326  * This is the end of Protocol specific defines.
 327  */
 328
 329 static int storvsc_ringbuffer_size = (128 * 1024);
 330 static u32 max_outstanding_req_per_channel;
 331 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 332
 333 static int storvsc_vcpus_per_sub_channel = 4;
 334 static unsigned int storvsc_max_hw_queues;
 335
 336 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 337 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 338
 339 module_param(storvsc_max_hw_queues, uint, 0644);
 340 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
 341
 342 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 343 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 344
 345 static int ring_avail_percent_lowater = 10;
 346 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 347 MODULE_PARM_DESC(ring_avail_percent_lowater,
 348                 "Select a channel if available ring size > this in percent");
 349
 350 /*
 351  * Timeout in seconds for all devices managed by this driver.
 352  */
 353 static int storvsc_timeout = 180;
 354
 355 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 356 static struct scsi_transport_template *fc_transport_template;
 357 #endif
 358
 359 static struct scsi_host_template scsi_driver;
 360 static void storvsc_on_channel_callback(void *context);
 361
 362 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 363 #define STORVSC_MAX_TARGETS                             2
 364 #define STORVSC_MAX_CHANNELS                            8
 365
 366 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 367 #define STORVSC_FC_MAX_TARGETS                          128
 368 #define STORVSC_FC_MAX_CHANNELS                         8
 369
 370 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 371 #define STORVSC_IDE_MAX_TARGETS                         1
 372 #define STORVSC_IDE_MAX_CHANNELS                        1
 373
 374 /*
 375  * Upper bound on the size of a storvsc packet.
 376  */
 377 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
 378                               sizeof(struct vstor_packet))
 379
 380 struct storvsc_cmd_request {
 381         struct scsi_cmnd *cmd;
 382
 383         struct hv_device *device;
 384
 385         /* Synchronize the request/response if needed */
 386         struct completion wait_event;
 387
 388         struct vmbus_channel_packet_multipage_buffer mpb;
 389         struct vmbus_packet_mpb_array *payload;
 390         u32 payload_sz;
 391
 392         struct vstor_packet vstor_packet;
 393 };
 394
 395
 396 /* A storvsc device is a device object that contains a vmbus channel */
 397 struct storvsc_device {
 398         struct hv_device *device;
 399
 400         bool     destroy;
 401         bool     drain_notify;
 402         atomic_t num_outstanding_req;
 403         struct Scsi_Host *host;
 404
 405         wait_queue_head_t waiting_to_drain;
 406
 407         /*
 408          * Each unique Port/Path/Target represents 1 channel ie scsi
 409          * controller. In reality, the pathid, targetid is always 0
 410          * and the port is set by us
 411          */
 412         unsigned int port_number;
 413         unsigned char path_id;
 414         unsigned char target_id;
 415
 416         /*
 417          * Max I/O, the device can support.
 418          */
 419         u32   max_transfer_bytes;
 420         /*
 421          * Number of sub-channels we will open.
 422          */
 423         u16 num_sc;
 424         struct vmbus_channel **stor_chns;
 425         /*
 426          * Mask of CPUs bound to subchannels.
 427          */
 428         struct cpumask alloced_cpus;
 429         /*
 430          * Serializes modifications of stor_chns[] from storvsc_do_io()
 431          * and storvsc_change_target_cpu().
 432          */
 433         spinlock_t lock;
 434         /* Used for vsc/vsp channel reset process */
 435         struct storvsc_cmd_request init_request;
 436         struct storvsc_cmd_request reset_request;
 437         /*
 438          * Currently active port and node names for FC devices.
 439          */
 440         u64 node_name;
 441         u64 port_name;
 442 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 443         struct fc_rport *rport;
 444 #endif
 445 };
 446
 447 struct hv_host_device {
 448         struct hv_device *dev;
 449         unsigned int port;
 450         unsigned char path;
 451         unsigned char target;
 452         struct workqueue_struct *handle_error_wq;
 453         struct work_struct host_scan_work;
 454         struct Scsi_Host *host;
 455 };
 456
 457 struct storvsc_scan_work {
 458         struct work_struct work;
 459         struct Scsi_Host *host;
 460         u8 lun;
 461         u8 tgt_id;
 462 };
 463
 464 static void storvsc_device_scan(struct work_struct *work)
 465 {
 466         struct storvsc_scan_work *wrk;
 467         struct scsi_device *sdev;
 468
 469         wrk = container_of(work, struct storvsc_scan_work, work);
 470
 471         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 472         if (!sdev)
 473                 goto done;
 474         scsi_rescan_device(&sdev->sdev_gendev);
 475         scsi_device_put(sdev);
 476
 477 done:
 478         kfree(wrk);
 479 }
 480
 481 static void storvsc_host_scan(struct work_struct *work)
 482 {
 483         struct Scsi_Host *host;
 484         struct scsi_device *sdev;
 485         struct hv_host_device *host_device =
 486                 container_of(work, struct hv_host_device, host_scan_work);
 487
 488         host = host_device->host;
 489         /*
 490          * Before scanning the host, first check to see if any of the
 491          * currently known devices have been hot removed. We issue a
 492          * "unit ready" command against all currently known devices.
 493          * This I/O will result in an error for devices that have been
 494          * removed. As part of handling the I/O error, we remove the device.
 495          *
 496          * When a LUN is added or removed, the host sends us a signal to
 497          * scan the host. Thus we are forced to discover the LUNs that
 498          * may have been removed this way.
 499          */
 500         mutex_lock(&host->scan_mutex);
 501         shost_for_each_device(sdev, host)
 502                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 503         mutex_unlock(&host->scan_mutex);
 504         /*
 505          * Now scan the host to discover LUNs that may have been added.
 506          */
 507         scsi_scan_host(host);
 508 }
 509
 510 static void storvsc_remove_lun(struct work_struct *work)
 511 {
 512         struct storvsc_scan_work *wrk;
 513         struct scsi_device *sdev;
 514
 515         wrk = container_of(work, struct storvsc_scan_work, work);
 516         if (!scsi_host_get(wrk->host))
 517                 goto done;
 518
 519         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 520
 521         if (sdev) {
 522                 scsi_remove_device(sdev);
 523                 scsi_device_put(sdev);
 524         }
 525         scsi_host_put(wrk->host);
 526
 527 done:
 528         kfree(wrk);
 529 }
 530
 531
 532 /*
 533  * We can get incoming messages from the host that are not in response to
 534  * messages that we have sent out. An example of this would be messages
 535  * received by the guest to notify dynamic addition/removal of LUNs. To
 536  * deal with potential race conditions where the driver may be in the
 537  * midst of being unloaded when we might receive an unsolicited message
 538  * from the host, we have implemented a mechanism to gurantee sequential
 539  * consistency:
 540  *
 541  * 1) Once the device is marked as being destroyed, we will fail all
 542  *    outgoing messages.
 543  * 2) We permit incoming messages when the device is being destroyed,
 544  *    only to properly account for messages already sent out.
 545  */
 546
 547 static inline struct storvsc_device *get_out_stor_device(
 548                                         struct hv_device *device)
 549 {
 550         struct storvsc_device *stor_device;
 551
 552         stor_device = hv_get_drvdata(device);
 553
 554         if (stor_device && stor_device->destroy)
 555                 stor_device = NULL;
 556
 557         return stor_device;
 558 }
 559
 560
 561 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 562 {
 563         dev->drain_notify = true;
 564         wait_event(dev->waiting_to_drain,
 565                    atomic_read(&dev->num_outstanding_req) == 0);
 566         dev->drain_notify = false;
 567 }
 568
 569 static inline struct storvsc_device *get_in_stor_device(
 570                                         struct hv_device *device)
 571 {
 572         struct storvsc_device *stor_device;
 573
 574         stor_device = hv_get_drvdata(device);
 575
 576         if (!stor_device)
 577                 goto get_in_err;
 578
 579         /*
 580          * If the device is being destroyed; allow incoming
 581          * traffic only to cleanup outstanding requests.
 582          */
 583
 584         if (stor_device->destroy  &&
 585                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 586                 stor_device = NULL;
 587
 588 get_in_err:
 589         return stor_device;
 590
 591 }
 592
 593 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 594                                       u32 new)
 595 {
 596         struct storvsc_device *stor_device;
 597         struct vmbus_channel *cur_chn;
 598         bool old_is_alloced = false;
 599         struct hv_device *device;
 600         unsigned long flags;
 601         int cpu;
 602
 603         device = channel->primary_channel ?
 604                         channel->primary_channel->device_obj
 605                                 : channel->device_obj;
 606         stor_device = get_out_stor_device(device);
 607         if (!stor_device)
 608                 return;
 609
 610         /* See storvsc_do_io() -> get_og_chn(). */
 611         spin_lock_irqsave(&stor_device->lock, flags);
 612
 613         /*
 614          * Determines if the storvsc device has other channels assigned to
 615          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 616          * array.
 617          */
 618         if (device->channel != channel && device->channel->target_cpu == old) {
 619                 cur_chn = device->channel;
 620                 old_is_alloced = true;
 621                 goto old_is_alloced;
 622         }
 623         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 624                 if (cur_chn == channel)
 625                         continue;
 626                 if (cur_chn->target_cpu == old) {
 627                         old_is_alloced = true;
 628                         goto old_is_alloced;
 629                 }
 630         }
 631
 632 old_is_alloced:
 633         if (old_is_alloced)
 634                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 635         else
 636                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 637
 638         /* "Flush" the stor_chns array. */
 639         for_each_possible_cpu(cpu) {
 640                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 641                                         cpu, &stor_device->alloced_cpus))
 642                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 643         }
 644
 645         WRITE_ONCE(stor_device->stor_chns[new], channel);
 646         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 647
 648         spin_unlock_irqrestore(&stor_device->lock, flags);
 649 }
 650
 651 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 652 {
 653         struct storvsc_cmd_request *request =
 654                 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
 655
 656         if (rqst_addr == VMBUS_RQST_INIT)
 657                 return VMBUS_RQST_INIT;
 658         if (rqst_addr == VMBUS_RQST_RESET)
 659                 return VMBUS_RQST_RESET;
 660
 661         /*
 662          * Cannot return an ID of 0, which is reserved for an unsolicited
 663          * message from Hyper-V.
 664          */
 665         return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
 666 }
 667
 668 static void handle_sc_creation(struct vmbus_channel *new_sc)
 669 {
 670         struct hv_device *device = new_sc->primary_channel->device_obj;
 671         struct device *dev = &device->device;
 672         struct storvsc_device *stor_device;
 673         struct vmstorage_channel_properties props;
 674         int ret;
 675
 676         stor_device = get_out_stor_device(device);
 677         if (!stor_device)
 678                 return;
 679
 680         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 681         new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
 682
 683         new_sc->next_request_id_callback = storvsc_next_request_id;
 684
 685         ret = vmbus_open(new_sc,
 686                          storvsc_ringbuffer_size,
 687                          storvsc_ringbuffer_size,
 688                          (void *)&props,
 689                          sizeof(struct vmstorage_channel_properties),
 690                          storvsc_on_channel_callback, new_sc);
 691
 692         /* In case vmbus_open() fails, we don't use the sub-channel. */
 693         if (ret != 0) {
 694                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 695                 return;
 696         }
 697
 698         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 699
 700         /* Add the sub-channel to the array of available channels. */
 701         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 702         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 703 }
 704
 705 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 706 {
 707         struct device *dev = &device->device;
 708         struct storvsc_device *stor_device;
 709         int num_sc;
 710         struct storvsc_cmd_request *request;
 711         struct vstor_packet *vstor_packet;
 712         int ret, t;
 713
 714         /*
 715          * If the number of CPUs is artificially restricted, such as
 716          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 717          * sub-channels >= the number of CPUs. These sub-channels
 718          * should not be created. The primary channel is already created
 719          * and assigned to one CPU, so check against # CPUs - 1.
 720          */
 721         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 722         if (!num_sc)
 723                 return;
 724
 725         stor_device = get_out_stor_device(device);
 726         if (!stor_device)
 727                 return;
 728
 729         stor_device->num_sc = num_sc;
 730         request = &stor_device->init_request;
 731         vstor_packet = &request->vstor_packet;
 732
 733         /*
 734          * Establish a handler for dealing with subchannels.
 735          */
 736         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 737
 738         /*
 739          * Request the host to create sub-channels.
 740          */
 741         memset(request, 0, sizeof(struct storvsc_cmd_request));
 742         init_completion(&request->wait_event);
 743         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 744         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 745         vstor_packet->sub_channel_count = num_sc;
 746
 747         ret = vmbus_sendpacket(device->channel, vstor_packet,
 748                                sizeof(struct vstor_packet),
 749                                VMBUS_RQST_INIT,
 750                                VM_PKT_DATA_INBAND,
 751                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 752
 753         if (ret != 0) {
 754                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 755                 return;
 756         }
 757
 758         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 759         if (t == 0) {
 760                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 761                 return;
 762         }
 763
 764         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 765             vstor_packet->status != 0) {
 766                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 767                         vstor_packet->operation, vstor_packet->status);
 768                 return;
 769         }
 770
 771         /*
 772          * We need to do nothing here, because vmbus_process_offer()
 773          * invokes channel->sc_creation_callback, which will open and use
 774          * the sub-channel(s).
 775          */
 776 }
 777
 778 static void cache_wwn(struct storvsc_device *stor_device,
 779                       struct vstor_packet *vstor_packet)
 780 {
 781         /*
 782          * Cache the currently active port and node ww names.
 783          */
 784         if (vstor_packet->wwn_packet.primary_active) {
 785                 stor_device->node_name =
 786                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 787                 stor_device->port_name =
 788                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 789         } else {
 790                 stor_device->node_name =
 791                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 792                 stor_device->port_name =
 793                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 794         }
 795 }
 796
 797
 798 static int storvsc_execute_vstor_op(struct hv_device *device,
 799                                     struct storvsc_cmd_request *request,
 800                                     bool status_check)
 801 {
 802         struct storvsc_device *stor_device;
 803         struct vstor_packet *vstor_packet;
 804         int ret, t;
 805
 806         stor_device = get_out_stor_device(device);
 807         if (!stor_device)
 808                 return -ENODEV;
 809
 810         vstor_packet = &request->vstor_packet;
 811
 812         init_completion(&request->wait_event);
 813         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 814
 815         ret = vmbus_sendpacket(device->channel, vstor_packet,
 816                                sizeof(struct vstor_packet),
 817                                VMBUS_RQST_INIT,
 818                                VM_PKT_DATA_INBAND,
 819                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 820         if (ret != 0)
 821                 return ret;
 822
 823         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 824         if (t == 0)
 825                 return -ETIMEDOUT;
 826
 827         if (!status_check)
 828                 return ret;
 829
 830         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 831             vstor_packet->status != 0)
 832                 return -EINVAL;
 833
 834         return ret;
 835 }
 836
 837 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 838 {
 839         struct storvsc_device *stor_device;
 840         struct storvsc_cmd_request *request;
 841         struct vstor_packet *vstor_packet;
 842         int ret, i;
 843         int max_chns;
 844         bool process_sub_channels = false;
 845
 846         stor_device = get_out_stor_device(device);
 847         if (!stor_device)
 848                 return -ENODEV;
 849
 850         request = &stor_device->init_request;
 851         vstor_packet = &request->vstor_packet;
 852
 853         /*
 854          * Now, initiate the vsc/vsp initialization protocol on the open
 855          * channel
 856          */
 857         memset(request, 0, sizeof(struct storvsc_cmd_request));
 858         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 859         ret = storvsc_execute_vstor_op(device, request, true);
 860         if (ret)
 861                 return ret;
 862         /*
 863          * Query host supported protocol version.
 864          */
 865
 866         for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
 867                 /* reuse the packet for version range supported */
 868                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 869                 vstor_packet->operation =
 870                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 871
 872                 vstor_packet->version.major_minor = protocol_version[i];
 873
 874                 /*
 875                  * The revision number is only used in Windows; set it to 0.
 876                  */
 877                 vstor_packet->version.revision = 0;
 878                 ret = storvsc_execute_vstor_op(device, request, false);
 879                 if (ret != 0)
 880                         return ret;
 881
 882                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 883                         return -EINVAL;
 884
 885                 if (vstor_packet->status == 0) {
 886                         vmstor_proto_version = protocol_version[i];
 887
 888                         break;
 889                 }
 890         }
 891
 892         if (vstor_packet->status != 0) {
 893                 dev_err(&device->device, "Obsolete Hyper-V version\n");
 894                 return -EINVAL;
 895         }
 896
 897
 898         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 899         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 900         ret = storvsc_execute_vstor_op(device, request, true);
 901         if (ret != 0)
 902                 return ret;
 903
 904         /*
 905          * Check to see if multi-channel support is there.
 906          * Hosts that implement protocol version of 5.1 and above
 907          * support multi-channel.
 908          */
 909         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 910
 911         /*
 912          * Allocate state to manage the sub-channels.
 913          * We allocate an array based on the numbers of possible CPUs
 914          * (Hyper-V does not support cpu online/offline).
 915          * This Array will be sparseley populated with unique
 916          * channels - primary + sub-channels.
 917          * We will however populate all the slots to evenly distribute
 918          * the load.
 919          */
 920         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 921                                          GFP_KERNEL);
 922         if (stor_device->stor_chns == NULL)
 923                 return -ENOMEM;
 924
 925         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 926
 927         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 928         cpumask_set_cpu(device->channel->target_cpu,
 929                         &stor_device->alloced_cpus);
 930
 931         if (vstor_packet->storage_channel_properties.flags &
 932             STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 933                 process_sub_channels = true;
 934
 935         stor_device->max_transfer_bytes =
 936                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 937
 938         if (!is_fc)
 939                 goto done;
 940
 941         /*
 942          * For FC devices retrieve FC HBA data.
 943          */
 944         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 945         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 946         ret = storvsc_execute_vstor_op(device, request, true);
 947         if (ret != 0)
 948                 return ret;
 949
 950         /*
 951          * Cache the currently active port and node ww names.
 952          */
 953         cache_wwn(stor_device, vstor_packet);
 954
 955 done:
 956
 957         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 958         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 959         ret = storvsc_execute_vstor_op(device, request, true);
 960         if (ret != 0)
 961                 return ret;
 962
 963         if (process_sub_channels)
 964                 handle_multichannel_storage(device, max_chns);
 965
 966         return ret;
 967 }
 968
 969 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 970                                 struct scsi_cmnd *scmnd,
 971                                 struct Scsi_Host *host,
 972                                 u8 asc, u8 ascq)
 973 {
 974         struct storvsc_scan_work *wrk;
 975         void (*process_err_fn)(struct work_struct *work);
 976         struct hv_host_device *host_dev = shost_priv(host);
 977
 978         switch (SRB_STATUS(vm_srb->srb_status)) {
 979         case SRB_STATUS_ERROR:
 980         case SRB_STATUS_ABORTED:
 981         case SRB_STATUS_INVALID_REQUEST:
 982         case SRB_STATUS_INTERNAL_ERROR:
 983                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
 984                         /* Check for capacity change */
 985                         if ((asc == 0x2a) && (ascq == 0x9)) {
 986                                 process_err_fn = storvsc_device_scan;
 987                                 /* Retry the I/O that triggered this. */
 988                                 set_host_byte(scmnd, DID_REQUEUE);
 989                                 goto do_work;
 990                         }
 991
 992                         /*
 993                          * Check for "Operating parameters have changed"
 994                          * due to Hyper-V changing the VHD/VHDX BlockSize
 995                          * when adding/removing a differencing disk. This
 996                          * causes discard_granularity to change, so do a
 997                          * rescan to pick up the new granularity. We don't
 998                          * want scsi_report_sense() to output a message
 999                          * that a sysadmin wouldn't know what to do with.
1000                          */
1001                         if ((asc == 0x3f) && (ascq != 0x03) &&
1002                                         (ascq != 0x0e)) {
1003                                 process_err_fn = storvsc_device_scan;
1004                                 set_host_byte(scmnd, DID_REQUEUE);
1005                                 goto do_work;
1006                         }
1007
1008                         /*
1009                          * Otherwise, let upper layer deal with the
1010                          * error when sense message is present
1011                          */
1012                         return;
1013                 }
1014
1015                 /*
1016                  * If there is an error; offline the device since all
1017                  * error recovery strategies would have already been
1018                  * deployed on the host side. However, if the command
1019                  * were a pass-through command deal with it appropriately.
1020                  */
1021                 switch (scmnd->cmnd[0]) {
1022                 case ATA_16:
1023                 case ATA_12:
1024                         set_host_byte(scmnd, DID_PASSTHROUGH);
1025                         break;
1026                 /*
1027                  * On some Hyper-V hosts TEST_UNIT_READY command can
1028                  * return SRB_STATUS_ERROR. Let the upper level code
1029                  * deal with it based on the sense information.
1030                  */
1031                 case TEST_UNIT_READY:
1032                         break;
1033                 default:
1034                         set_host_byte(scmnd, DID_ERROR);
1035                 }
1036                 return;
1037
1038         case SRB_STATUS_INVALID_LUN:
1039                 set_host_byte(scmnd, DID_NO_CONNECT);
1040                 process_err_fn = storvsc_remove_lun;
1041                 goto do_work;
1042
1043         }
1044         return;
1045
1046 do_work:
1047         /*
1048          * We need to schedule work to process this error; schedule it.
1049          */
1050         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1051         if (!wrk) {
1052                 set_host_byte(scmnd, DID_BAD_TARGET);
1053                 return;
1054         }
1055
1056         wrk->host = host;
1057         wrk->lun = vm_srb->lun;
1058         wrk->tgt_id = vm_srb->target_id;
1059         INIT_WORK(&wrk->work, process_err_fn);
1060         queue_work(host_dev->handle_error_wq, &wrk->work);
1061 }
1062
1063
1064 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1065                                        struct storvsc_device *stor_dev)
1066 {
1067         struct scsi_cmnd *scmnd = cmd_request->cmd;
1068         struct scsi_sense_hdr sense_hdr;
1069         struct vmscsi_request *vm_srb;
1070         u32 data_transfer_length;
1071         struct Scsi_Host *host;
1072         u32 payload_sz = cmd_request->payload_sz;
1073         void *payload = cmd_request->payload;
1074         bool sense_ok;
1075
1076         host = stor_dev->host;
1077
1078         vm_srb = &cmd_request->vstor_packet.vm_srb;
1079         data_transfer_length = vm_srb->data_transfer_length;
1080
1081         scmnd->result = vm_srb->scsi_status;
1082
1083         if (scmnd->result) {
1084                 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1085                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1086
1087                 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1088                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1089                                              &sense_hdr);
1090         }
1091
1092         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1093                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1094                                          sense_hdr.ascq);
1095                 /*
1096                  * The Windows driver set data_transfer_length on
1097                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1098                  * is untouched.  In these cases we set it to 0.
1099                  */
1100                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1101                         data_transfer_length = 0;
1102         }
1103
1104         /* Validate data_transfer_length (from Hyper-V) */
1105         if (data_transfer_length > cmd_request->payload->range.len)
1106                 data_transfer_length = cmd_request->payload->range.len;
1107
1108         scsi_set_resid(scmnd,
1109                 cmd_request->payload->range.len - data_transfer_length);
1110
1111         scsi_done(scmnd);
1112
1113         if (payload_sz >
1114                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1115                 kfree(payload);
1116 }
1117
1118 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1119                                   struct vstor_packet *vstor_packet,
1120                                   struct storvsc_cmd_request *request)
1121 {
1122         struct vstor_packet *stor_pkt;
1123         struct hv_device *device = stor_device->device;
1124
1125         stor_pkt = &request->vstor_packet;
1126
1127         /*
1128          * The current SCSI handling on the host side does
1129          * not correctly handle:
1130          * INQUIRY command with page code parameter set to 0x80
1131          * MODE_SENSE command with cmd[2] == 0x1c
1132          *
1133          * Setup srb and scsi status so this won't be fatal.
1134          * We do this so we can distinguish truly fatal failues
1135          * (srb status == 0x4) and off-line the device in that case.
1136          */
1137
1138         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1139            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1140                 vstor_packet->vm_srb.scsi_status = 0;
1141                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1142         }
1143
1144         /* Copy over the status...etc */
1145         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1146         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1147
1148         /*
1149          * Copy over the sense_info_length, but limit to the known max
1150          * size if Hyper-V returns a bad value.
1151          */
1152         stor_pkt->vm_srb.sense_info_length = min_t(u8, STORVSC_SENSE_BUFFER_SIZE,
1153                 vstor_packet->vm_srb.sense_info_length);
1154
1155         if (vstor_packet->vm_srb.scsi_status != 0 ||
1156             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1157
1158                 /*
1159                  * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1160                  * return errors when detecting devices using TEST_UNIT_READY,
1161                  * and logging these as errors produces unhelpful noise.
1162                  */
1163                 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1164                         STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1165
1166                 storvsc_log(device, loglevel,
1167                         "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1168                         scsi_cmd_to_rq(request->cmd)->tag,
1169                         stor_pkt->vm_srb.cdb[0],
1170                         vstor_packet->vm_srb.scsi_status,
1171                         vstor_packet->vm_srb.srb_status,
1172                         vstor_packet->status);
1173         }
1174
1175         if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1176             (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1177                 memcpy(request->cmd->sense_buffer,
1178                        vstor_packet->vm_srb.sense_data,
1179                        stor_pkt->vm_srb.sense_info_length);
1180
1181         stor_pkt->vm_srb.data_transfer_length =
1182                 vstor_packet->vm_srb.data_transfer_length;
1183
1184         storvsc_command_completion(request, stor_device);
1185
1186         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1187                 stor_device->drain_notify)
1188                 wake_up(&stor_device->waiting_to_drain);
1189 }
1190
1191 static void storvsc_on_receive(struct storvsc_device *stor_device,
1192                              struct vstor_packet *vstor_packet,
1193                              struct storvsc_cmd_request *request)
1194 {
1195         struct hv_host_device *host_dev;
1196         switch (vstor_packet->operation) {
1197         case VSTOR_OPERATION_COMPLETE_IO:
1198                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1199                 break;
1200
1201         case VSTOR_OPERATION_REMOVE_DEVICE:
1202         case VSTOR_OPERATION_ENUMERATE_BUS:
1203                 host_dev = shost_priv(stor_device->host);
1204                 queue_work(
1205                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1206                 break;
1207
1208         case VSTOR_OPERATION_FCHBA_DATA:
1209                 cache_wwn(stor_device, vstor_packet);
1210 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1211                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1212                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1213 #endif
1214                 break;
1215         default:
1216                 break;
1217         }
1218 }
1219
1220 static void storvsc_on_channel_callback(void *context)
1221 {
1222         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1223         const struct vmpacket_descriptor *desc;
1224         struct hv_device *device;
1225         struct storvsc_device *stor_device;
1226         struct Scsi_Host *shost;
1227         unsigned long time_limit = jiffies + msecs_to_jiffies(CALLBACK_TIMEOUT);
1228
1229         if (channel->primary_channel != NULL)
1230                 device = channel->primary_channel->device_obj;
1231         else
1232                 device = channel->device_obj;
1233
1234         stor_device = get_in_stor_device(device);
1235         if (!stor_device)
1236                 return;
1237
1238         shost = stor_device->host;
1239
1240         foreach_vmbus_pkt(desc, channel) {
1241                 struct vstor_packet *packet = hv_pkt_data(desc);
1242                 struct storvsc_cmd_request *request = NULL;
1243                 u32 pktlen = hv_pkt_datalen(desc);
1244                 u64 rqst_id = desc->trans_id;
1245                 u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
1246                         sizeof(enum vstor_packet_operation);
1247
1248                 if (unlikely(time_after(jiffies, time_limit))) {
1249                         hv_pkt_iter_close(channel);
1250                         return;
1251                 }
1252
1253                 if (pktlen < minlen) {
1254                         dev_err(&device->device,
1255                                 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1256                                 rqst_id, pktlen, minlen);
1257                         continue;
1258                 }
1259
1260                 if (rqst_id == VMBUS_RQST_INIT) {
1261                         request = &stor_device->init_request;
1262                 } else if (rqst_id == VMBUS_RQST_RESET) {
1263                         request = &stor_device->reset_request;
1264                 } else {
1265                         /* Hyper-V can send an unsolicited message with ID of 0 */
1266                         if (rqst_id == 0) {
1267                                 /*
1268                                  * storvsc_on_receive() looks at the vstor_packet in the message
1269                                  * from the ring buffer.
1270                                  *
1271                                  * - If the operation in the vstor_packet is COMPLETE_IO, then
1272                                  *   we call storvsc_on_io_completion(), and dereference the
1273                                  *   guest memory address.  Make sure we don't call
1274                                  *   storvsc_on_io_completion() with a guest memory address
1275                                  *   that is zero if Hyper-V were to construct and send such
1276                                  *   a bogus packet.
1277                                  *
1278                                  * - If the operation in the vstor_packet is FCHBA_DATA, then
1279                                  *   we call cache_wwn(), and access the data payload area of
1280                                  *   the packet (wwn_packet); however, there is no guarantee
1281                                  *   that the packet is big enough to contain such area.
1282                                  *   Future-proof the code by rejecting such a bogus packet.
1283                                  */
1284                                 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1285                                     packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1286                                         dev_err(&device->device, "Invalid packet with ID of 0\n");
1287                                         continue;
1288                                 }
1289                         } else {
1290                                 struct scsi_cmnd *scmnd;
1291
1292                                 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1293                                 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1294                                 if (scmnd == NULL) {
1295                                         dev_err(&device->device, "Incorrect transaction ID\n");
1296                                         continue;
1297                                 }
1298                                 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1299                                 scsi_dma_unmap(scmnd);
1300                         }
1301
1302                         storvsc_on_receive(stor_device, packet, request);
1303                         continue;
1304                 }
1305
1306                 memcpy(&request->vstor_packet, packet,
1307                        sizeof(struct vstor_packet));
1308                 complete(&request->wait_event);
1309         }
1310 }
1311
1312 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1313                                   bool is_fc)
1314 {
1315         struct vmstorage_channel_properties props;
1316         int ret;
1317
1318         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1319
1320         device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1321         device->channel->next_request_id_callback = storvsc_next_request_id;
1322
1323         ret = vmbus_open(device->channel,
1324                          ring_size,
1325                          ring_size,
1326                          (void *)&props,
1327                          sizeof(struct vmstorage_channel_properties),
1328                          storvsc_on_channel_callback, device->channel);
1329
1330         if (ret != 0)
1331                 return ret;
1332
1333         ret = storvsc_channel_init(device, is_fc);
1334
1335         return ret;
1336 }
1337
1338 static int storvsc_dev_remove(struct hv_device *device)
1339 {
1340         struct storvsc_device *stor_device;
1341
1342         stor_device = hv_get_drvdata(device);
1343
1344         stor_device->destroy = true;
1345
1346         /* Make sure flag is set before waiting */
1347         wmb();
1348
1349         /*
1350          * At this point, all outbound traffic should be disable. We
1351          * only allow inbound traffic (responses) to proceed so that
1352          * outstanding requests can be completed.
1353          */
1354
1355         storvsc_wait_to_drain(stor_device);
1356
1357         /*
1358          * Since we have already drained, we don't need to busy wait
1359          * as was done in final_release_stor_device()
1360          * Note that we cannot set the ext pointer to NULL until
1361          * we have drained - to drain the outgoing packets, we need to
1362          * allow incoming packets.
1363          */
1364         hv_set_drvdata(device, NULL);
1365
1366         /* Close the channel */
1367         vmbus_close(device->channel);
1368
1369         kfree(stor_device->stor_chns);
1370         kfree(stor_device);
1371         return 0;
1372 }
1373
1374 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1375                                         u16 q_num)
1376 {
1377         u16 slot = 0;
1378         u16 hash_qnum;
1379         const struct cpumask *node_mask;
1380         int num_channels, tgt_cpu;
1381
1382         if (stor_device->num_sc == 0) {
1383                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1384                 return stor_device->device->channel;
1385         }
1386
1387         /*
1388          * Our channel array is sparsley populated and we
1389          * initiated I/O on a processor/hw-q that does not
1390          * currently have a designated channel. Fix this.
1391          * The strategy is simple:
1392          * I. Ensure NUMA locality
1393          * II. Distribute evenly (best effort)
1394          */
1395
1396         node_mask = cpumask_of_node(cpu_to_node(q_num));
1397
1398         num_channels = 0;
1399         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1400                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1401                         num_channels++;
1402         }
1403         if (num_channels == 0) {
1404                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1405                 return stor_device->device->channel;
1406         }
1407
1408         hash_qnum = q_num;
1409         while (hash_qnum >= num_channels)
1410                 hash_qnum -= num_channels;
1411
1412         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1413                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1414                         continue;
1415                 if (slot == hash_qnum)
1416                         break;
1417                 slot++;
1418         }
1419
1420         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1421
1422         return stor_device->stor_chns[q_num];
1423 }
1424
1425
1426 static int storvsc_do_io(struct hv_device *device,
1427                          struct storvsc_cmd_request *request, u16 q_num)
1428 {
1429         struct storvsc_device *stor_device;
1430         struct vstor_packet *vstor_packet;
1431         struct vmbus_channel *outgoing_channel, *channel;
1432         unsigned long flags;
1433         int ret = 0;
1434         const struct cpumask *node_mask;
1435         int tgt_cpu;
1436
1437         vstor_packet = &request->vstor_packet;
1438         stor_device = get_out_stor_device(device);
1439
1440         if (!stor_device)
1441                 return -ENODEV;
1442
1443
1444         request->device  = device;
1445         /*
1446          * Select an appropriate channel to send the request out.
1447          */
1448         /* See storvsc_change_target_cpu(). */
1449         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1450         if (outgoing_channel != NULL) {
1451                 if (outgoing_channel->target_cpu == q_num) {
1452                         /*
1453                          * Ideally, we want to pick a different channel if
1454                          * available on the same NUMA node.
1455                          */
1456                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1457                         for_each_cpu_wrap(tgt_cpu,
1458                                  &stor_device->alloced_cpus, q_num + 1) {
1459                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1460                                         continue;
1461                                 if (tgt_cpu == q_num)
1462                                         continue;
1463                                 channel = READ_ONCE(
1464                                         stor_device->stor_chns[tgt_cpu]);
1465                                 if (channel == NULL)
1466                                         continue;
1467                                 if (hv_get_avail_to_write_percent(
1468                                                         &channel->outbound)
1469                                                 > ring_avail_percent_lowater) {
1470                                         outgoing_channel = channel;
1471                                         goto found_channel;
1472                                 }
1473                         }
1474
1475                         /*
1476                          * All the other channels on the same NUMA node are
1477                          * busy. Try to use the channel on the current CPU
1478                          */
1479                         if (hv_get_avail_to_write_percent(
1480                                                 &outgoing_channel->outbound)
1481                                         > ring_avail_percent_lowater)
1482                                 goto found_channel;
1483
1484                         /*
1485                          * If we reach here, all the channels on the current
1486                          * NUMA node are busy. Try to find a channel in
1487                          * other NUMA nodes
1488                          */
1489                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1490                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1491                                         continue;
1492                                 channel = READ_ONCE(
1493                                         stor_device->stor_chns[tgt_cpu]);
1494                                 if (channel == NULL)
1495                                         continue;
1496                                 if (hv_get_avail_to_write_percent(
1497                                                         &channel->outbound)
1498                                                 > ring_avail_percent_lowater) {
1499                                         outgoing_channel = channel;
1500                                         goto found_channel;
1501                                 }
1502                         }
1503                 }
1504         } else {
1505                 spin_lock_irqsave(&stor_device->lock, flags);
1506                 outgoing_channel = stor_device->stor_chns[q_num];
1507                 if (outgoing_channel != NULL) {
1508                         spin_unlock_irqrestore(&stor_device->lock, flags);
1509                         goto found_channel;
1510                 }
1511                 outgoing_channel = get_og_chn(stor_device, q_num);
1512                 spin_unlock_irqrestore(&stor_device->lock, flags);
1513         }
1514
1515 found_channel:
1516         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1517
1518         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1519
1520
1521         vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1522
1523
1524         vstor_packet->vm_srb.data_transfer_length =
1525         request->payload->range.len;
1526
1527         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1528
1529         if (request->payload->range.len) {
1530
1531                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1532                                 request->payload, request->payload_sz,
1533                                 vstor_packet,
1534                                 sizeof(struct vstor_packet),
1535                                 (unsigned long)request);
1536         } else {
1537                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1538                                sizeof(struct vstor_packet),
1539                                (unsigned long)request,
1540                                VM_PKT_DATA_INBAND,
1541                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1542         }
1543
1544         if (ret != 0)
1545                 return ret;
1546
1547         atomic_inc(&stor_device->num_outstanding_req);
1548
1549         return ret;
1550 }
1551
1552 static int storvsc_device_alloc(struct scsi_device *sdevice)
1553 {
1554         /*
1555          * Set blist flag to permit the reading of the VPD pages even when
1556          * the target may claim SPC-2 compliance. MSFT targets currently
1557          * claim SPC-2 compliance while they implement post SPC-2 features.
1558          * With this flag we can correctly handle WRITE_SAME_16 issues.
1559          *
1560          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1561          * still supports REPORT LUN.
1562          */
1563         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1564
1565         return 0;
1566 }
1567
1568 static int storvsc_device_configure(struct scsi_device *sdevice)
1569 {
1570         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1571
1572         /* storvsc devices don't support MAINTENANCE_IN SCSI cmd */
1573         sdevice->no_report_opcodes = 1;
1574         sdevice->no_write_same = 1;
1575
1576         /*
1577          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1578          * if the device is a MSFT virtual device.  If the host is
1579          * WIN10 or newer, allow write_same.
1580          */
1581         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1582                 switch (vmstor_proto_version) {
1583                 case VMSTOR_PROTO_VERSION_WIN8:
1584                 case VMSTOR_PROTO_VERSION_WIN8_1:
1585                         sdevice->scsi_level = SCSI_SPC_3;
1586                         break;
1587                 }
1588
1589                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1590                         sdevice->no_write_same = 0;
1591         }
1592
1593         return 0;
1594 }
1595
1596 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1597                            sector_t capacity, int *info)
1598 {
1599         sector_t nsect = capacity;
1600         sector_t cylinders = nsect;
1601         int heads, sectors_pt;
1602
1603         /*
1604          * We are making up these values; let us keep it simple.
1605          */
1606         heads = 0xff;
1607         sectors_pt = 0x3f;      /* Sectors per track */
1608         sector_div(cylinders, heads * sectors_pt);
1609         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1610                 cylinders = 0xffff;
1611
1612         info[0] = heads;
1613         info[1] = sectors_pt;
1614         info[2] = (int)cylinders;
1615
1616         return 0;
1617 }
1618
1619 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1620 {
1621         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1622         struct hv_device *device = host_dev->dev;
1623
1624         struct storvsc_device *stor_device;
1625         struct storvsc_cmd_request *request;
1626         struct vstor_packet *vstor_packet;
1627         int ret, t;
1628
1629         stor_device = get_out_stor_device(device);
1630         if (!stor_device)
1631                 return FAILED;
1632
1633         request = &stor_device->reset_request;
1634         vstor_packet = &request->vstor_packet;
1635         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1636
1637         init_completion(&request->wait_event);
1638
1639         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1640         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1641         vstor_packet->vm_srb.path_id = stor_device->path_id;
1642
1643         ret = vmbus_sendpacket(device->channel, vstor_packet,
1644                                sizeof(struct vstor_packet),
1645                                VMBUS_RQST_RESET,
1646                                VM_PKT_DATA_INBAND,
1647                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1648         if (ret != 0)
1649                 return FAILED;
1650
1651         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1652         if (t == 0)
1653                 return TIMEOUT_ERROR;
1654
1655
1656         /*
1657          * At this point, all outstanding requests in the adapter
1658          * should have been flushed out and return to us
1659          * There is a potential race here where the host may be in
1660          * the process of responding when we return from here.
1661          * Just wait for all in-transit packets to be accounted for
1662          * before we return from here.
1663          */
1664         storvsc_wait_to_drain(stor_device);
1665
1666         return SUCCESS;
1667 }
1668
1669 /*
1670  * The host guarantees to respond to each command, although I/O latencies might
1671  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1672  * chance to perform EH.
1673  */
1674 static enum scsi_timeout_action storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1675 {
1676 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1677         if (scmnd->device->host->transportt == fc_transport_template)
1678                 return fc_eh_timed_out(scmnd);
1679 #endif
1680         return SCSI_EH_RESET_TIMER;
1681 }
1682
1683 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1684 {
1685         bool allowed = true;
1686         u8 scsi_op = scmnd->cmnd[0];
1687
1688         switch (scsi_op) {
1689         /* the host does not handle WRITE_SAME, log accident usage */
1690         case WRITE_SAME:
1691         /*
1692          * smartd sends this command and the host does not handle
1693          * this. So, don't send it.
1694          */
1695         case SET_WINDOW:
1696                 set_host_byte(scmnd, DID_ERROR);
1697                 allowed = false;
1698                 break;
1699         default:
1700                 break;
1701         }
1702         return allowed;
1703 }
1704
1705 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1706 {
1707         int ret;
1708         struct hv_host_device *host_dev = shost_priv(host);
1709         struct hv_device *dev = host_dev->dev;
1710         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1711         struct scatterlist *sgl;
1712         struct vmscsi_request *vm_srb;
1713         struct vmbus_packet_mpb_array  *payload;
1714         u32 payload_sz;
1715         u32 length;
1716
1717         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1718                 /*
1719                  * On legacy hosts filter unimplemented commands.
1720                  * Future hosts are expected to correctly handle
1721                  * unsupported commands. Furthermore, it is
1722                  * possible that some of the currently
1723                  * unsupported commands maybe supported in
1724                  * future versions of the host.
1725                  */
1726                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1727                         scsi_done(scmnd);
1728                         return 0;
1729                 }
1730         }
1731
1732         /* Setup the cmd request */
1733         cmd_request->cmd = scmnd;
1734
1735         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1736         vm_srb = &cmd_request->vstor_packet.vm_srb;
1737         vm_srb->time_out_value = 60;
1738
1739         vm_srb->srb_flags |=
1740                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1741
1742         if (scmnd->device->tagged_supported) {
1743                 vm_srb->srb_flags |=
1744                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1745                 vm_srb->queue_tag = SP_UNTAGGED;
1746                 vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
1747         }
1748
1749         /* Build the SRB */
1750         switch (scmnd->sc_data_direction) {
1751         case DMA_TO_DEVICE:
1752                 vm_srb->data_in = WRITE_TYPE;
1753                 vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
1754                 break;
1755         case DMA_FROM_DEVICE:
1756                 vm_srb->data_in = READ_TYPE;
1757                 vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
1758                 break;
1759         case DMA_NONE:
1760                 vm_srb->data_in = UNKNOWN_TYPE;
1761                 vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1762                 break;
1763         default:
1764                 /*
1765                  * This is DMA_BIDIRECTIONAL or something else we are never
1766                  * supposed to see here.
1767                  */
1768                 WARN(1, "Unexpected data direction: %d\n",
1769                      scmnd->sc_data_direction);
1770                 return -EINVAL;
1771         }
1772
1773
1774         vm_srb->port_number = host_dev->port;
1775         vm_srb->path_id = scmnd->device->channel;
1776         vm_srb->target_id = scmnd->device->id;
1777         vm_srb->lun = scmnd->device->lun;
1778
1779         vm_srb->cdb_length = scmnd->cmd_len;
1780
1781         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1782
1783         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1784
1785         length = scsi_bufflen(scmnd);
1786         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1787         payload_sz = 0;
1788
1789         if (scsi_sg_count(scmnd)) {
1790                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1791                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1792                 struct scatterlist *sg;
1793                 unsigned long hvpfn, hvpfns_to_add;
1794                 int j, i = 0, sg_count;
1795
1796                 payload_sz = (hvpg_count * sizeof(u64) +
1797                               sizeof(struct vmbus_packet_mpb_array));
1798
1799                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1800                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1801                         if (!payload)
1802                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1803                 }
1804
1805                 payload->range.len = length;
1806                 payload->range.offset = offset_in_hvpg;
1807
1808                 sg_count = scsi_dma_map(scmnd);
1809                 if (sg_count < 0) {
1810                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1811                         goto err_free_payload;
1812                 }
1813
1814                 for_each_sg(sgl, sg, sg_count, j) {
1815                         /*
1816                          * Init values for the current sgl entry. hvpfns_to_add
1817                          * is in units of Hyper-V size pages. Handling the
1818                          * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1819                          * values of sgl->offset that are larger than PAGE_SIZE.
1820                          * Such offsets are handled even on other than the first
1821                          * sgl entry, provided they are a multiple of PAGE_SIZE.
1822                          */
1823                         hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1824                         hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1825                                                  sg_dma_len(sg)) - hvpfn;
1826
1827                         /*
1828                          * Fill the next portion of the PFN array with
1829                          * sequential Hyper-V PFNs for the continguous physical
1830                          * memory described by the sgl entry. The end of the
1831                          * last sgl should be reached at the same time that
1832                          * the PFN array is filled.
1833                          */
1834                         while (hvpfns_to_add--)
1835                                 payload->range.pfn_array[i++] = hvpfn++;
1836                 }
1837         }
1838
1839         cmd_request->payload = payload;
1840         cmd_request->payload_sz = payload_sz;
1841
1842         /* Invokes the vsc to start an IO */
1843         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1844         put_cpu();
1845
1846         if (ret)
1847                 scsi_dma_unmap(scmnd);
1848
1849         if (ret == -EAGAIN) {
1850                 /* no more space */
1851                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1852                 goto err_free_payload;
1853         }
1854
1855         return 0;
1856
1857 err_free_payload:
1858         if (payload_sz > sizeof(cmd_request->mpb))
1859                 kfree(payload);
1860
1861         return ret;
1862 }
1863
1864 static struct scsi_host_template scsi_driver = {
1865         .module =               THIS_MODULE,
1866         .name =                 "storvsc_host_t",
1867         .cmd_size =             sizeof(struct storvsc_cmd_request),
1868         .bios_param =           storvsc_get_chs,
1869         .queuecommand =         storvsc_queuecommand,
1870         .eh_host_reset_handler =        storvsc_host_reset_handler,
1871         .proc_name =            "storvsc_host",
1872         .eh_timed_out =         storvsc_eh_timed_out,
1873         .slave_alloc =          storvsc_device_alloc,
1874         .slave_configure =      storvsc_device_configure,
1875         .cmd_per_lun =          2048,
1876         .this_id =              -1,
1877         /* Ensure there are no gaps in presented sgls */
1878         .virt_boundary_mask =   HV_HYP_PAGE_SIZE - 1,
1879         .no_write_same =        1,
1880         .track_queue_depth =    1,
1881         .change_queue_depth =   storvsc_change_queue_depth,
1882 };
1883
1884 enum {
1885         SCSI_GUID,
1886         IDE_GUID,
1887         SFC_GUID,
1888 };
1889
1890 static const struct hv_vmbus_device_id id_table[] = {
1891         /* SCSI guid */
1892         { HV_SCSI_GUID,
1893           .driver_data = SCSI_GUID
1894         },
1895         /* IDE guid */
1896         { HV_IDE_GUID,
1897           .driver_data = IDE_GUID
1898         },
1899         /* Fibre Channel GUID */
1900         {
1901           HV_SYNTHFC_GUID,
1902           .driver_data = SFC_GUID
1903         },
1904         { },
1905 };
1906
1907 MODULE_DEVICE_TABLE(vmbus, id_table);
1908
1909 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1910
1911 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1912 {
1913         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1914 }
1915
1916 static int storvsc_probe(struct hv_device *device,
1917                         const struct hv_vmbus_device_id *dev_id)
1918 {
1919         int ret;
1920         int num_cpus = num_online_cpus();
1921         int num_present_cpus = num_present_cpus();
1922         struct Scsi_Host *host;
1923         struct hv_host_device *host_dev;
1924         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1925         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1926         int target = 0;
1927         struct storvsc_device *stor_device;
1928         int max_sub_channels = 0;
1929         u32 max_xfer_bytes;
1930
1931         /*
1932          * We support sub-channels for storage on SCSI and FC controllers.
1933          * The number of sub-channels offerred is based on the number of
1934          * VCPUs in the guest.
1935          */
1936         if (!dev_is_ide)
1937                 max_sub_channels =
1938                         (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1939
1940         scsi_driver.can_queue = max_outstanding_req_per_channel *
1941                                 (max_sub_channels + 1) *
1942                                 (100 - ring_avail_percent_lowater) / 100;
1943
1944         host = scsi_host_alloc(&scsi_driver,
1945                                sizeof(struct hv_host_device));
1946         if (!host)
1947                 return -ENOMEM;
1948
1949         host_dev = shost_priv(host);
1950         memset(host_dev, 0, sizeof(struct hv_host_device));
1951
1952         host_dev->port = host->host_no;
1953         host_dev->dev = device;
1954         host_dev->host = host;
1955
1956
1957         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1958         if (!stor_device) {
1959                 ret = -ENOMEM;
1960                 goto err_out0;
1961         }
1962
1963         stor_device->destroy = false;
1964         init_waitqueue_head(&stor_device->waiting_to_drain);
1965         stor_device->device = device;
1966         stor_device->host = host;
1967         spin_lock_init(&stor_device->lock);
1968         hv_set_drvdata(device, stor_device);
1969         dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
1970
1971         stor_device->port_number = host->host_no;
1972         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1973         if (ret)
1974                 goto err_out1;
1975
1976         host_dev->path = stor_device->path_id;
1977         host_dev->target = stor_device->target_id;
1978
1979         switch (dev_id->driver_data) {
1980         case SFC_GUID:
1981                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1982                 host->max_id = STORVSC_FC_MAX_TARGETS;
1983                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1984 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1985                 host->transportt = fc_transport_template;
1986 #endif
1987                 break;
1988
1989         case SCSI_GUID:
1990                 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1991                 host->max_id = STORVSC_MAX_TARGETS;
1992                 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1993                 break;
1994
1995         default:
1996                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1997                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1998                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1999                 break;
2000         }
2001         /* max cmd length */
2002         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
2003         /*
2004          * Any reasonable Hyper-V configuration should provide
2005          * max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
2006          * protecting it from any weird value.
2007          */
2008         max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
2009         /* max_hw_sectors_kb */
2010         host->max_sectors = max_xfer_bytes >> 9;
2011         /*
2012          * There are 2 requirements for Hyper-V storvsc sgl segments,
2013          * based on which the below calculation for max segments is
2014          * done:
2015          *
2016          * 1. Except for the first and last sgl segment, all sgl segments
2017          *    should be align to HV_HYP_PAGE_SIZE, that also means the
2018          *    maximum number of segments in a sgl can be calculated by
2019          *    dividing the total max transfer length by HV_HYP_PAGE_SIZE.
2020          *
2021          * 2. Except for the first and last, each entry in the SGL must
2022          *    have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2023          */
2024         host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2025         /*
2026          * For non-IDE disks, the host supports multiple channels.
2027          * Set the number of HW queues we are supporting.
2028          */
2029         if (!dev_is_ide) {
2030                 if (storvsc_max_hw_queues > num_present_cpus) {
2031                         storvsc_max_hw_queues = 0;
2032                         storvsc_log(device, STORVSC_LOGGING_WARN,
2033                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2034                 }
2035                 if (storvsc_max_hw_queues)
2036                         host->nr_hw_queues = storvsc_max_hw_queues;
2037                 else
2038                         host->nr_hw_queues = num_present_cpus;
2039         }
2040
2041         /*
2042          * Set the error handler work queue.
2043          */
2044         host_dev->handle_error_wq =
2045                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2046                                                 0,
2047                                                 host->host_no);
2048         if (!host_dev->handle_error_wq) {
2049                 ret = -ENOMEM;
2050                 goto err_out2;
2051         }
2052         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2053         /* Register the HBA and start the scsi bus scan */
2054         ret = scsi_add_host(host, &device->device);
2055         if (ret != 0)
2056                 goto err_out3;
2057
2058         if (!dev_is_ide) {
2059                 scsi_scan_host(host);
2060         } else {
2061                 target = (device->dev_instance.b[5] << 8 |
2062                          device->dev_instance.b[4]);
2063                 ret = scsi_add_device(host, 0, target, 0);
2064                 if (ret)
2065                         goto err_out4;
2066         }
2067 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2068         if (host->transportt == fc_transport_template) {
2069                 struct fc_rport_identifiers ids = {
2070                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2071                 };
2072
2073                 fc_host_node_name(host) = stor_device->node_name;
2074                 fc_host_port_name(host) = stor_device->port_name;
2075                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2076                 if (!stor_device->rport) {
2077                         ret = -ENOMEM;
2078                         goto err_out4;
2079                 }
2080         }
2081 #endif
2082         return 0;
2083
2084 err_out4:
2085         scsi_remove_host(host);
2086
2087 err_out3:
2088         destroy_workqueue(host_dev->handle_error_wq);
2089
2090 err_out2:
2091         /*
2092          * Once we have connected with the host, we would need to
2093          * invoke storvsc_dev_remove() to rollback this state and
2094          * this call also frees up the stor_device; hence the jump around
2095          * err_out1 label.
2096          */
2097         storvsc_dev_remove(device);
2098         goto err_out0;
2099
2100 err_out1:
2101         kfree(stor_device->stor_chns);
2102         kfree(stor_device);
2103
2104 err_out0:
2105         scsi_host_put(host);
2106         return ret;
2107 }
2108
2109 /* Change a scsi target's queue depth */
2110 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2111 {
2112         if (queue_depth > scsi_driver.can_queue)
2113                 queue_depth = scsi_driver.can_queue;
2114
2115         return scsi_change_queue_depth(sdev, queue_depth);
2116 }
2117
2118 static void storvsc_remove(struct hv_device *dev)
2119 {
2120         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2121         struct Scsi_Host *host = stor_device->host;
2122         struct hv_host_device *host_dev = shost_priv(host);
2123
2124 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2125         if (host->transportt == fc_transport_template) {
2126                 fc_remote_port_delete(stor_device->rport);
2127                 fc_remove_host(host);
2128         }
2129 #endif
2130         destroy_workqueue(host_dev->handle_error_wq);
2131         scsi_remove_host(host);
2132         storvsc_dev_remove(dev);
2133         scsi_host_put(host);
2134 }
2135
2136 static int storvsc_suspend(struct hv_device *hv_dev)
2137 {
2138         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2139         struct Scsi_Host *host = stor_device->host;
2140         struct hv_host_device *host_dev = shost_priv(host);
2141
2142         storvsc_wait_to_drain(stor_device);
2143
2144         drain_workqueue(host_dev->handle_error_wq);
2145
2146         vmbus_close(hv_dev->channel);
2147
2148         kfree(stor_device->stor_chns);
2149         stor_device->stor_chns = NULL;
2150
2151         cpumask_clear(&stor_device->alloced_cpus);
2152
2153         return 0;
2154 }
2155
2156 static int storvsc_resume(struct hv_device *hv_dev)
2157 {
2158         int ret;
2159
2160         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2161                                      hv_dev_is_fc(hv_dev));
2162         return ret;
2163 }
2164
2165 static struct hv_driver storvsc_drv = {
2166         .name = KBUILD_MODNAME,
2167         .id_table = id_table,
2168         .probe = storvsc_probe,
2169         .remove = storvsc_remove,
2170         .suspend = storvsc_suspend,
2171         .resume = storvsc_resume,
2172         .driver = {
2173                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2174         },
2175 };
2176
2177 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2178 static struct fc_function_template fc_transport_functions = {
2179         .show_host_node_name = 1,
2180         .show_host_port_name = 1,
2181 };
2182 #endif
2183
2184 static int __init storvsc_drv_init(void)
2185 {
2186         int ret;
2187
2188         /*
2189          * Divide the ring buffer data size (which is 1 page less
2190          * than the ring buffer size since that page is reserved for
2191          * the ring buffer indices) by the max request size (which is
2192          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2193          */
2194         max_outstanding_req_per_channel =
2195                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2196                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2197                 sizeof(struct vstor_packet) + sizeof(u64),
2198                 sizeof(u64)));
2199
2200 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2201         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2202         if (!fc_transport_template)
2203                 return -ENODEV;
2204 #endif
2205
2206         ret = vmbus_driver_register(&storvsc_drv);
2207
2208 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2209         if (ret)
2210                 fc_release_transport(fc_transport_template);
2211 #endif
2212
2213         return ret;
2214 }
2215
2216 static void __exit storvsc_drv_exit(void)
2217 {
2218         vmbus_driver_unregister(&storvsc_drv);
2219 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2220         fc_release_transport(fc_transport_template);
2221 #endif
2222 }
2223
2224 MODULE_LICENSE("GPL");
2225 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2226 module_init(storvsc_drv_init);
2227 module_exit(storvsc_drv_exit);