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; a subset of the codes used here.
 348  */
 349
 350 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 351 #define SRB_STATUS_QUEUE_FROZEN         0x40
 352 #define SRB_STATUS_INVALID_LUN  0x20
 353 #define SRB_STATUS_SUCCESS      0x01
 354 #define SRB_STATUS_ABORTED      0x02
 355 #define SRB_STATUS_ERROR        0x04
 356 #define SRB_STATUS_DATA_OVERRUN 0x12
 357
 358 #define SRB_STATUS(status) \
 359         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 360 /*
 361  * This is the end of Protocol specific defines.
 362  */
 363
 364 static int storvsc_ringbuffer_size = (128 * 1024);
 365 static u32 max_outstanding_req_per_channel;
 366 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 367
 368 static int storvsc_vcpus_per_sub_channel = 4;
 369 static unsigned int storvsc_max_hw_queues;
 370
 371 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 372 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 373
 374 module_param(storvsc_max_hw_queues, uint, 0644);
 375 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
 376
 377 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 378 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 379
 380 static int ring_avail_percent_lowater = 10;
 381 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 382 MODULE_PARM_DESC(ring_avail_percent_lowater,
 383                 "Select a channel if available ring size > this in percent");
 384
 385 /*
 386  * Timeout in seconds for all devices managed by this driver.
 387  */
 388 static int storvsc_timeout = 180;
 389
 390 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 391 static struct scsi_transport_template *fc_transport_template;
 392 #endif
 393
 394 static struct scsi_host_template scsi_driver;
 395 static void storvsc_on_channel_callback(void *context);
 396
 397 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 398 #define STORVSC_MAX_TARGETS                             2
 399 #define STORVSC_MAX_CHANNELS                            8
 400
 401 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 402 #define STORVSC_FC_MAX_TARGETS                          128
 403 #define STORVSC_FC_MAX_CHANNELS                         8
 404
 405 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 406 #define STORVSC_IDE_MAX_TARGETS                         1
 407 #define STORVSC_IDE_MAX_CHANNELS                        1
 408
 409 struct storvsc_cmd_request {
 410         struct scsi_cmnd *cmd;
 411
 412         struct hv_device *device;
 413
 414         /* Synchronize the request/response if needed */
 415         struct completion wait_event;
 416
 417         struct vmbus_channel_packet_multipage_buffer mpb;
 418         struct vmbus_packet_mpb_array *payload;
 419         u32 payload_sz;
 420
 421         struct vstor_packet vstor_packet;
 422 };
 423
 424
 425 /* A storvsc device is a device object that contains a vmbus channel */
 426 struct storvsc_device {
 427         struct hv_device *device;
 428
 429         bool     destroy;
 430         bool     drain_notify;
 431         atomic_t num_outstanding_req;
 432         struct Scsi_Host *host;
 433
 434         wait_queue_head_t waiting_to_drain;
 435
 436         /*
 437          * Each unique Port/Path/Target represents 1 channel ie scsi
 438          * controller. In reality, the pathid, targetid is always 0
 439          * and the port is set by us
 440          */
 441         unsigned int port_number;
 442         unsigned char path_id;
 443         unsigned char target_id;
 444
 445         /*
 446          * The size of the vmscsi_request has changed in win8. The
 447          * additional size is because of new elements added to the
 448          * structure. These elements are valid only when we are talking
 449          * to a win8 host.
 450          * Track the correction to size we need to apply. This value
 451          * will likely change during protocol negotiation but it is
 452          * valid to start by assuming pre-Win8.
 453          */
 454         int vmscsi_size_delta;
 455
 456         /*
 457          * Max I/O, the device can support.
 458          */
 459         u32   max_transfer_bytes;
 460         /*
 461          * Number of sub-channels we will open.
 462          */
 463         u16 num_sc;
 464         struct vmbus_channel **stor_chns;
 465         /*
 466          * Mask of CPUs bound to subchannels.
 467          */
 468         struct cpumask alloced_cpus;
 469         /*
 470          * Serializes modifications of stor_chns[] from storvsc_do_io()
 471          * and storvsc_change_target_cpu().
 472          */
 473         spinlock_t lock;
 474         /* Used for vsc/vsp channel reset process */
 475         struct storvsc_cmd_request init_request;
 476         struct storvsc_cmd_request reset_request;
 477         /*
 478          * Currently active port and node names for FC devices.
 479          */
 480         u64 node_name;
 481         u64 port_name;
 482 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 483         struct fc_rport *rport;
 484 #endif
 485 };
 486
 487 struct hv_host_device {
 488         struct hv_device *dev;
 489         unsigned int port;
 490         unsigned char path;
 491         unsigned char target;
 492         struct workqueue_struct *handle_error_wq;
 493         struct work_struct host_scan_work;
 494         struct Scsi_Host *host;
 495 };
 496
 497 struct storvsc_scan_work {
 498         struct work_struct work;
 499         struct Scsi_Host *host;
 500         u8 lun;
 501         u8 tgt_id;
 502 };
 503
 504 static void storvsc_device_scan(struct work_struct *work)
 505 {
 506         struct storvsc_scan_work *wrk;
 507         struct scsi_device *sdev;
 508
 509         wrk = container_of(work, struct storvsc_scan_work, work);
 510
 511         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 512         if (!sdev)
 513                 goto done;
 514         scsi_rescan_device(&sdev->sdev_gendev);
 515         scsi_device_put(sdev);
 516
 517 done:
 518         kfree(wrk);
 519 }
 520
 521 static void storvsc_host_scan(struct work_struct *work)
 522 {
 523         struct Scsi_Host *host;
 524         struct scsi_device *sdev;
 525         struct hv_host_device *host_device =
 526                 container_of(work, struct hv_host_device, host_scan_work);
 527
 528         host = host_device->host;
 529         /*
 530          * Before scanning the host, first check to see if any of the
 531          * currrently known devices have been hot removed. We issue a
 532          * "unit ready" command against all currently known devices.
 533          * This I/O will result in an error for devices that have been
 534          * removed. As part of handling the I/O error, we remove the device.
 535          *
 536          * When a LUN is added or removed, the host sends us a signal to
 537          * scan the host. Thus we are forced to discover the LUNs that
 538          * may have been removed this way.
 539          */
 540         mutex_lock(&host->scan_mutex);
 541         shost_for_each_device(sdev, host)
 542                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 543         mutex_unlock(&host->scan_mutex);
 544         /*
 545          * Now scan the host to discover LUNs that may have been added.
 546          */
 547         scsi_scan_host(host);
 548 }
 549
 550 static void storvsc_remove_lun(struct work_struct *work)
 551 {
 552         struct storvsc_scan_work *wrk;
 553         struct scsi_device *sdev;
 554
 555         wrk = container_of(work, struct storvsc_scan_work, work);
 556         if (!scsi_host_get(wrk->host))
 557                 goto done;
 558
 559         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 560
 561         if (sdev) {
 562                 scsi_remove_device(sdev);
 563                 scsi_device_put(sdev);
 564         }
 565         scsi_host_put(wrk->host);
 566
 567 done:
 568         kfree(wrk);
 569 }
 570
 571
 572 /*
 573  * We can get incoming messages from the host that are not in response to
 574  * messages that we have sent out. An example of this would be messages
 575  * received by the guest to notify dynamic addition/removal of LUNs. To
 576  * deal with potential race conditions where the driver may be in the
 577  * midst of being unloaded when we might receive an unsolicited message
 578  * from the host, we have implemented a mechanism to gurantee sequential
 579  * consistency:
 580  *
 581  * 1) Once the device is marked as being destroyed, we will fail all
 582  *    outgoing messages.
 583  * 2) We permit incoming messages when the device is being destroyed,
 584  *    only to properly account for messages already sent out.
 585  */
 586
 587 static inline struct storvsc_device *get_out_stor_device(
 588                                         struct hv_device *device)
 589 {
 590         struct storvsc_device *stor_device;
 591
 592         stor_device = hv_get_drvdata(device);
 593
 594         if (stor_device && stor_device->destroy)
 595                 stor_device = NULL;
 596
 597         return stor_device;
 598 }
 599
 600
 601 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 602 {
 603         dev->drain_notify = true;
 604         wait_event(dev->waiting_to_drain,
 605                    atomic_read(&dev->num_outstanding_req) == 0);
 606         dev->drain_notify = false;
 607 }
 608
 609 static inline struct storvsc_device *get_in_stor_device(
 610                                         struct hv_device *device)
 611 {
 612         struct storvsc_device *stor_device;
 613
 614         stor_device = hv_get_drvdata(device);
 615
 616         if (!stor_device)
 617                 goto get_in_err;
 618
 619         /*
 620          * If the device is being destroyed; allow incoming
 621          * traffic only to cleanup outstanding requests.
 622          */
 623
 624         if (stor_device->destroy  &&
 625                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 626                 stor_device = NULL;
 627
 628 get_in_err:
 629         return stor_device;
 630
 631 }
 632
 633 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 634                                       u32 new)
 635 {
 636         struct storvsc_device *stor_device;
 637         struct vmbus_channel *cur_chn;
 638         bool old_is_alloced = false;
 639         struct hv_device *device;
 640         unsigned long flags;
 641         int cpu;
 642
 643         device = channel->primary_channel ?
 644                         channel->primary_channel->device_obj
 645                                 : channel->device_obj;
 646         stor_device = get_out_stor_device(device);
 647         if (!stor_device)
 648                 return;
 649
 650         /* See storvsc_do_io() -> get_og_chn(). */
 651         spin_lock_irqsave(&stor_device->lock, flags);
 652
 653         /*
 654          * Determines if the storvsc device has other channels assigned to
 655          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 656          * array.
 657          */
 658         if (device->channel != channel && device->channel->target_cpu == old) {
 659                 cur_chn = device->channel;
 660                 old_is_alloced = true;
 661                 goto old_is_alloced;
 662         }
 663         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 664                 if (cur_chn == channel)
 665                         continue;
 666                 if (cur_chn->target_cpu == old) {
 667                         old_is_alloced = true;
 668                         goto old_is_alloced;
 669                 }
 670         }
 671
 672 old_is_alloced:
 673         if (old_is_alloced)
 674                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 675         else
 676                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 677
 678         /* "Flush" the stor_chns array. */
 679         for_each_possible_cpu(cpu) {
 680                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 681                                         cpu, &stor_device->alloced_cpus))
 682                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 683         }
 684
 685         WRITE_ONCE(stor_device->stor_chns[new], channel);
 686         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 687
 688         spin_unlock_irqrestore(&stor_device->lock, flags);
 689 }
 690
 691 static void handle_sc_creation(struct vmbus_channel *new_sc)
 692 {
 693         struct hv_device *device = new_sc->primary_channel->device_obj;
 694         struct device *dev = &device->device;
 695         struct storvsc_device *stor_device;
 696         struct vmstorage_channel_properties props;
 697         int ret;
 698
 699         stor_device = get_out_stor_device(device);
 700         if (!stor_device)
 701                 return;
 702
 703         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 704
 705         /*
 706          * The size of vmbus_requestor is an upper bound on the number of requests
 707          * that can be in-progress at any one time across all channels.
 708          */
 709         new_sc->rqstor_size = scsi_driver.can_queue;
 710
 711         ret = vmbus_open(new_sc,
 712                          storvsc_ringbuffer_size,
 713                          storvsc_ringbuffer_size,
 714                          (void *)&props,
 715                          sizeof(struct vmstorage_channel_properties),
 716                          storvsc_on_channel_callback, new_sc);
 717
 718         /* In case vmbus_open() fails, we don't use the sub-channel. */
 719         if (ret != 0) {
 720                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 721                 return;
 722         }
 723
 724         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 725
 726         /* Add the sub-channel to the array of available channels. */
 727         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 728         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 729 }
 730
 731 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 732 {
 733         struct device *dev = &device->device;
 734         struct storvsc_device *stor_device;
 735         int num_sc;
 736         struct storvsc_cmd_request *request;
 737         struct vstor_packet *vstor_packet;
 738         int ret, t;
 739
 740         /*
 741          * If the number of CPUs is artificially restricted, such as
 742          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 743          * sub-channels >= the number of CPUs. These sub-channels
 744          * should not be created. The primary channel is already created
 745          * and assigned to one CPU, so check against # CPUs - 1.
 746          */
 747         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 748         if (!num_sc)
 749                 return;
 750
 751         stor_device = get_out_stor_device(device);
 752         if (!stor_device)
 753                 return;
 754
 755         stor_device->num_sc = num_sc;
 756         request = &stor_device->init_request;
 757         vstor_packet = &request->vstor_packet;
 758
 759         /*
 760          * Establish a handler for dealing with subchannels.
 761          */
 762         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 763
 764         /*
 765          * Request the host to create sub-channels.
 766          */
 767         memset(request, 0, sizeof(struct storvsc_cmd_request));
 768         init_completion(&request->wait_event);
 769         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 770         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 771         vstor_packet->sub_channel_count = num_sc;
 772
 773         ret = vmbus_sendpacket(device->channel, vstor_packet,
 774                                (sizeof(struct vstor_packet) -
 775                                stor_device->vmscsi_size_delta),
 776                                (unsigned long)request,
 777                                VM_PKT_DATA_INBAND,
 778                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 779
 780         if (ret != 0) {
 781                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 782                 return;
 783         }
 784
 785         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 786         if (t == 0) {
 787                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 788                 return;
 789         }
 790
 791         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 792             vstor_packet->status != 0) {
 793                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 794                         vstor_packet->operation, vstor_packet->status);
 795                 return;
 796         }
 797
 798         /*
 799          * We need to do nothing here, because vmbus_process_offer()
 800          * invokes channel->sc_creation_callback, which will open and use
 801          * the sub-channel(s).
 802          */
 803 }
 804
 805 static void cache_wwn(struct storvsc_device *stor_device,
 806                       struct vstor_packet *vstor_packet)
 807 {
 808         /*
 809          * Cache the currently active port and node ww names.
 810          */
 811         if (vstor_packet->wwn_packet.primary_active) {
 812                 stor_device->node_name =
 813                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 814                 stor_device->port_name =
 815                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 816         } else {
 817                 stor_device->node_name =
 818                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 819                 stor_device->port_name =
 820                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 821         }
 822 }
 823
 824
 825 static int storvsc_execute_vstor_op(struct hv_device *device,
 826                                     struct storvsc_cmd_request *request,
 827                                     bool status_check)
 828 {
 829         struct storvsc_device *stor_device;
 830         struct vstor_packet *vstor_packet;
 831         int ret, t;
 832
 833         stor_device = get_out_stor_device(device);
 834         if (!stor_device)
 835                 return -ENODEV;
 836
 837         vstor_packet = &request->vstor_packet;
 838
 839         init_completion(&request->wait_event);
 840         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 841
 842         ret = vmbus_sendpacket(device->channel, vstor_packet,
 843                                (sizeof(struct vstor_packet) -
 844                                stor_device->vmscsi_size_delta),
 845                                (unsigned long)request,
 846                                VM_PKT_DATA_INBAND,
 847                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 848         if (ret != 0)
 849                 return ret;
 850
 851         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 852         if (t == 0)
 853                 return -ETIMEDOUT;
 854
 855         if (!status_check)
 856                 return ret;
 857
 858         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 859             vstor_packet->status != 0)
 860                 return -EINVAL;
 861
 862         return ret;
 863 }
 864
 865 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 866 {
 867         struct storvsc_device *stor_device;
 868         struct storvsc_cmd_request *request;
 869         struct vstor_packet *vstor_packet;
 870         int ret, i;
 871         int max_chns;
 872         bool process_sub_channels = false;
 873
 874         stor_device = get_out_stor_device(device);
 875         if (!stor_device)
 876                 return -ENODEV;
 877
 878         request = &stor_device->init_request;
 879         vstor_packet = &request->vstor_packet;
 880
 881         /*
 882          * Now, initiate the vsc/vsp initialization protocol on the open
 883          * channel
 884          */
 885         memset(request, 0, sizeof(struct storvsc_cmd_request));
 886         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 887         ret = storvsc_execute_vstor_op(device, request, true);
 888         if (ret)
 889                 return ret;
 890         /*
 891          * Query host supported protocol version.
 892          */
 893
 894         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 895                 /* reuse the packet for version range supported */
 896                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 897                 vstor_packet->operation =
 898                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 899
 900                 vstor_packet->version.major_minor =
 901                         vmstor_protocols[i].protocol_version;
 902
 903                 /*
 904                  * The revision number is only used in Windows; set it to 0.
 905                  */
 906                 vstor_packet->version.revision = 0;
 907                 ret = storvsc_execute_vstor_op(device, request, false);
 908                 if (ret != 0)
 909                         return ret;
 910
 911                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 912                         return -EINVAL;
 913
 914                 if (vstor_packet->status == 0) {
 915                         vmstor_proto_version =
 916                                 vmstor_protocols[i].protocol_version;
 917
 918                         sense_buffer_size =
 919                                 vmstor_protocols[i].sense_buffer_size;
 920
 921                         stor_device->vmscsi_size_delta =
 922                                 vmstor_protocols[i].vmscsi_size_delta;
 923
 924                         break;
 925                 }
 926         }
 927
 928         if (vstor_packet->status != 0)
 929                 return -EINVAL;
 930
 931
 932         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 933         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 934         ret = storvsc_execute_vstor_op(device, request, true);
 935         if (ret != 0)
 936                 return ret;
 937
 938         /*
 939          * Check to see if multi-channel support is there.
 940          * Hosts that implement protocol version of 5.1 and above
 941          * support multi-channel.
 942          */
 943         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 944
 945         /*
 946          * Allocate state to manage the sub-channels.
 947          * We allocate an array based on the numbers of possible CPUs
 948          * (Hyper-V does not support cpu online/offline).
 949          * This Array will be sparseley populated with unique
 950          * channels - primary + sub-channels.
 951          * We will however populate all the slots to evenly distribute
 952          * the load.
 953          */
 954         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 955                                          GFP_KERNEL);
 956         if (stor_device->stor_chns == NULL)
 957                 return -ENOMEM;
 958
 959         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 960
 961         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 962         cpumask_set_cpu(device->channel->target_cpu,
 963                         &stor_device->alloced_cpus);
 964
 965         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 966                 if (vstor_packet->storage_channel_properties.flags &
 967                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 968                         process_sub_channels = true;
 969         }
 970         stor_device->max_transfer_bytes =
 971                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 972
 973         if (!is_fc)
 974                 goto done;
 975
 976         /*
 977          * For FC devices retrieve FC HBA data.
 978          */
 979         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 980         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 981         ret = storvsc_execute_vstor_op(device, request, true);
 982         if (ret != 0)
 983                 return ret;
 984
 985         /*
 986          * Cache the currently active port and node ww names.
 987          */
 988         cache_wwn(stor_device, vstor_packet);
 989
 990 done:
 991
 992         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 993         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 994         ret = storvsc_execute_vstor_op(device, request, true);
 995         if (ret != 0)
 996                 return ret;
 997
 998         if (process_sub_channels)
 999                 handle_multichannel_storage(device, max_chns);
1000
1001         return ret;
1002 }
1003
1004 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1005                                 struct scsi_cmnd *scmnd,
1006                                 struct Scsi_Host *host,
1007                                 u8 asc, u8 ascq)
1008 {
1009         struct storvsc_scan_work *wrk;
1010         void (*process_err_fn)(struct work_struct *work);
1011         struct hv_host_device *host_dev = shost_priv(host);
1012         bool do_work = false;
1013
1014         switch (SRB_STATUS(vm_srb->srb_status)) {
1015         case SRB_STATUS_ERROR:
1016                 /*
1017                  * Let upper layer deal with error when
1018                  * sense message is present.
1019                  */
1020
1021                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1022                         break;
1023                 /*
1024                  * If there is an error; offline the device since all
1025                  * error recovery strategies would have already been
1026                  * deployed on the host side. However, if the command
1027                  * were a pass-through command deal with it appropriately.
1028                  */
1029                 switch (scmnd->cmnd[0]) {
1030                 case ATA_16:
1031                 case ATA_12:
1032                         set_host_byte(scmnd, DID_PASSTHROUGH);
1033                         break;
1034                 /*
1035                  * On Some Windows hosts TEST_UNIT_READY command can return
1036                  * SRB_STATUS_ERROR, let the upper level code deal with it
1037                  * based on the sense information.
1038                  */
1039                 case TEST_UNIT_READY:
1040                         break;
1041                 default:
1042                         set_host_byte(scmnd, DID_ERROR);
1043                 }
1044                 break;
1045         case SRB_STATUS_INVALID_LUN:
1046                 set_host_byte(scmnd, DID_NO_CONNECT);
1047                 do_work = true;
1048                 process_err_fn = storvsc_remove_lun;
1049                 break;
1050         case SRB_STATUS_ABORTED:
1051                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
1052                     (asc == 0x2a) && (ascq == 0x9)) {
1053                         do_work = true;
1054                         process_err_fn = storvsc_device_scan;
1055                         /*
1056                          * Retry the I/O that triggered this.
1057                          */
1058                         set_host_byte(scmnd, DID_REQUEUE);
1059                 }
1060                 break;
1061         }
1062
1063         if (!do_work)
1064                 return;
1065
1066         /*
1067          * We need to schedule work to process this error; schedule it.
1068          */
1069         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1070         if (!wrk) {
1071                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1072                 return;
1073         }
1074
1075         wrk->host = host;
1076         wrk->lun = vm_srb->lun;
1077         wrk->tgt_id = vm_srb->target_id;
1078         INIT_WORK(&wrk->work, process_err_fn);
1079         queue_work(host_dev->handle_error_wq, &wrk->work);
1080 }
1081
1082
1083 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1084                                        struct storvsc_device *stor_dev)
1085 {
1086         struct scsi_cmnd *scmnd = cmd_request->cmd;
1087         struct scsi_sense_hdr sense_hdr;
1088         struct vmscsi_request *vm_srb;
1089         u32 data_transfer_length;
1090         struct Scsi_Host *host;
1091         u32 payload_sz = cmd_request->payload_sz;
1092         void *payload = cmd_request->payload;
1093
1094         host = stor_dev->host;
1095
1096         vm_srb = &cmd_request->vstor_packet.vm_srb;
1097         data_transfer_length = vm_srb->data_transfer_length;
1098
1099         scmnd->result = vm_srb->scsi_status;
1100
1101         if (scmnd->result) {
1102                 if (scsi_normalize_sense(scmnd->sense_buffer,
1103                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1104                     !(sense_hdr.sense_key == NOT_READY &&
1105                                  sense_hdr.asc == 0x03A) &&
1106                     do_logging(STORVSC_LOGGING_ERROR))
1107                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1108                                              &sense_hdr);
1109         }
1110
1111         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1112                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1113                                          sense_hdr.ascq);
1114                 /*
1115                  * The Windows driver set data_transfer_length on
1116                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1117                  * is untouched.  In these cases we set it to 0.
1118                  */
1119                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1120                         data_transfer_length = 0;
1121         }
1122
1123         /* Validate data_transfer_length (from Hyper-V) */
1124         if (data_transfer_length > cmd_request->payload->range.len)
1125                 data_transfer_length = cmd_request->payload->range.len;
1126
1127         scsi_set_resid(scmnd,
1128                 cmd_request->payload->range.len - data_transfer_length);
1129
1130         scmnd->scsi_done(scmnd);
1131
1132         if (payload_sz >
1133                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1134                 kfree(payload);
1135 }
1136
1137 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1138                                   struct vstor_packet *vstor_packet,
1139                                   struct storvsc_cmd_request *request)
1140 {
1141         struct vstor_packet *stor_pkt;
1142         struct hv_device *device = stor_device->device;
1143
1144         stor_pkt = &request->vstor_packet;
1145
1146         /*
1147          * The current SCSI handling on the host side does
1148          * not correctly handle:
1149          * INQUIRY command with page code parameter set to 0x80
1150          * MODE_SENSE command with cmd[2] == 0x1c
1151          *
1152          * Setup srb and scsi status so this won't be fatal.
1153          * We do this so we can distinguish truly fatal failues
1154          * (srb status == 0x4) and off-line the device in that case.
1155          */
1156
1157         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1158            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1159                 vstor_packet->vm_srb.scsi_status = 0;
1160                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1161         }
1162
1163
1164         /* Copy over the status...etc */
1165         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1166         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1167
1168         /* Validate sense_info_length (from Hyper-V) */
1169         if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
1170                 vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1171
1172         stor_pkt->vm_srb.sense_info_length =
1173         vstor_packet->vm_srb.sense_info_length;
1174
1175         if (vstor_packet->vm_srb.scsi_status != 0 ||
1176             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1177                 storvsc_log(device, STORVSC_LOGGING_WARN,
1178                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1179                         stor_pkt->vm_srb.cdb[0],
1180                         vstor_packet->vm_srb.scsi_status,
1181                         vstor_packet->vm_srb.srb_status);
1182
1183         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1184                 /* CHECK_CONDITION */
1185                 if (vstor_packet->vm_srb.srb_status &
1186                         SRB_STATUS_AUTOSENSE_VALID) {
1187                         /* autosense data available */
1188
1189                         storvsc_log(device, STORVSC_LOGGING_WARN,
1190                                 "stor pkt %p autosense data valid - len %d\n",
1191                                 request, vstor_packet->vm_srb.sense_info_length);
1192
1193                         memcpy(request->cmd->sense_buffer,
1194                                vstor_packet->vm_srb.sense_data,
1195                                vstor_packet->vm_srb.sense_info_length);
1196
1197                 }
1198         }
1199
1200         stor_pkt->vm_srb.data_transfer_length =
1201         vstor_packet->vm_srb.data_transfer_length;
1202
1203         storvsc_command_completion(request, stor_device);
1204
1205         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1206                 stor_device->drain_notify)
1207                 wake_up(&stor_device->waiting_to_drain);
1208
1209
1210 }
1211
1212 static void storvsc_on_receive(struct storvsc_device *stor_device,
1213                              struct vstor_packet *vstor_packet,
1214                              struct storvsc_cmd_request *request)
1215 {
1216         struct hv_host_device *host_dev;
1217         switch (vstor_packet->operation) {
1218         case VSTOR_OPERATION_COMPLETE_IO:
1219                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1220                 break;
1221
1222         case VSTOR_OPERATION_REMOVE_DEVICE:
1223         case VSTOR_OPERATION_ENUMERATE_BUS:
1224                 host_dev = shost_priv(stor_device->host);
1225                 queue_work(
1226                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1227                 break;
1228
1229         case VSTOR_OPERATION_FCHBA_DATA:
1230                 cache_wwn(stor_device, vstor_packet);
1231 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1232                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1233                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1234 #endif
1235                 break;
1236         default:
1237                 break;
1238         }
1239 }
1240
1241 static void storvsc_on_channel_callback(void *context)
1242 {
1243         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1244         const struct vmpacket_descriptor *desc;
1245         struct hv_device *device;
1246         struct storvsc_device *stor_device;
1247
1248         if (channel->primary_channel != NULL)
1249                 device = channel->primary_channel->device_obj;
1250         else
1251                 device = channel->device_obj;
1252
1253         stor_device = get_in_stor_device(device);
1254         if (!stor_device)
1255                 return;
1256
1257         foreach_vmbus_pkt(desc, channel) {
1258                 void *packet = hv_pkt_data(desc);
1259                 struct storvsc_cmd_request *request;
1260                 u64 cmd_rqst;
1261
1262                 cmd_rqst = vmbus_request_addr(&channel->requestor,
1263                                               desc->trans_id);
1264                 if (cmd_rqst == VMBUS_RQST_ERROR) {
1265                         dev_err(&device->device,
1266                                 "Incorrect transaction id\n");
1267                         continue;
1268                 }
1269
1270                 request = (struct storvsc_cmd_request *)(unsigned long)cmd_rqst;
1271
1272                 if (hv_pkt_datalen(desc) < sizeof(struct vstor_packet) -
1273                                 stor_device->vmscsi_size_delta) {
1274                         dev_err(&device->device, "Invalid packet len\n");
1275                         continue;
1276                 }
1277
1278                 if (request == &stor_device->init_request ||
1279                     request == &stor_device->reset_request) {
1280                         memcpy(&request->vstor_packet, packet,
1281                                (sizeof(struct vstor_packet) - stor_device->vmscsi_size_delta));
1282                         complete(&request->wait_event);
1283                 } else {
1284                         storvsc_on_receive(stor_device, packet, request);
1285                 }
1286         }
1287 }
1288
1289 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1290                                   bool is_fc)
1291 {
1292         struct vmstorage_channel_properties props;
1293         int ret;
1294
1295         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1296
1297         /*
1298          * The size of vmbus_requestor is an upper bound on the number of requests
1299          * that can be in-progress at any one time across all channels.
1300          */
1301         device->channel->rqstor_size = scsi_driver.can_queue;
1302
1303         ret = vmbus_open(device->channel,
1304                          ring_size,
1305                          ring_size,
1306                          (void *)&props,
1307                          sizeof(struct vmstorage_channel_properties),
1308                          storvsc_on_channel_callback, device->channel);
1309
1310         if (ret != 0)
1311                 return ret;
1312
1313         ret = storvsc_channel_init(device, is_fc);
1314
1315         return ret;
1316 }
1317
1318 static int storvsc_dev_remove(struct hv_device *device)
1319 {
1320         struct storvsc_device *stor_device;
1321
1322         stor_device = hv_get_drvdata(device);
1323
1324         stor_device->destroy = true;
1325
1326         /* Make sure flag is set before waiting */
1327         wmb();
1328
1329         /*
1330          * At this point, all outbound traffic should be disable. We
1331          * only allow inbound traffic (responses) to proceed so that
1332          * outstanding requests can be completed.
1333          */
1334
1335         storvsc_wait_to_drain(stor_device);
1336
1337         /*
1338          * Since we have already drained, we don't need to busy wait
1339          * as was done in final_release_stor_device()
1340          * Note that we cannot set the ext pointer to NULL until
1341          * we have drained - to drain the outgoing packets, we need to
1342          * allow incoming packets.
1343          */
1344         hv_set_drvdata(device, NULL);
1345
1346         /* Close the channel */
1347         vmbus_close(device->channel);
1348
1349         kfree(stor_device->stor_chns);
1350         kfree(stor_device);
1351         return 0;
1352 }
1353
1354 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1355                                         u16 q_num)
1356 {
1357         u16 slot = 0;
1358         u16 hash_qnum;
1359         const struct cpumask *node_mask;
1360         int num_channels, tgt_cpu;
1361
1362         if (stor_device->num_sc == 0) {
1363                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1364                 return stor_device->device->channel;
1365         }
1366
1367         /*
1368          * Our channel array is sparsley populated and we
1369          * initiated I/O on a processor/hw-q that does not
1370          * currently have a designated channel. Fix this.
1371          * The strategy is simple:
1372          * I. Ensure NUMA locality
1373          * II. Distribute evenly (best effort)
1374          */
1375
1376         node_mask = cpumask_of_node(cpu_to_node(q_num));
1377
1378         num_channels = 0;
1379         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1380                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1381                         num_channels++;
1382         }
1383         if (num_channels == 0) {
1384                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1385                 return stor_device->device->channel;
1386         }
1387
1388         hash_qnum = q_num;
1389         while (hash_qnum >= num_channels)
1390                 hash_qnum -= num_channels;
1391
1392         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1393                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1394                         continue;
1395                 if (slot == hash_qnum)
1396                         break;
1397                 slot++;
1398         }
1399
1400         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1401
1402         return stor_device->stor_chns[q_num];
1403 }
1404
1405
1406 static int storvsc_do_io(struct hv_device *device,
1407                          struct storvsc_cmd_request *request, u16 q_num)
1408 {
1409         struct storvsc_device *stor_device;
1410         struct vstor_packet *vstor_packet;
1411         struct vmbus_channel *outgoing_channel, *channel;
1412         unsigned long flags;
1413         int ret = 0;
1414         const struct cpumask *node_mask;
1415         int tgt_cpu;
1416
1417         vstor_packet = &request->vstor_packet;
1418         stor_device = get_out_stor_device(device);
1419
1420         if (!stor_device)
1421                 return -ENODEV;
1422
1423
1424         request->device  = device;
1425         /*
1426          * Select an appropriate channel to send the request out.
1427          */
1428         /* See storvsc_change_target_cpu(). */
1429         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1430         if (outgoing_channel != NULL) {
1431                 if (outgoing_channel->target_cpu == q_num) {
1432                         /*
1433                          * Ideally, we want to pick a different channel if
1434                          * available on the same NUMA node.
1435                          */
1436                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1437                         for_each_cpu_wrap(tgt_cpu,
1438                                  &stor_device->alloced_cpus, q_num + 1) {
1439                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1440                                         continue;
1441                                 if (tgt_cpu == q_num)
1442                                         continue;
1443                                 channel = READ_ONCE(
1444                                         stor_device->stor_chns[tgt_cpu]);
1445                                 if (channel == NULL)
1446                                         continue;
1447                                 if (hv_get_avail_to_write_percent(
1448                                                         &channel->outbound)
1449                                                 > ring_avail_percent_lowater) {
1450                                         outgoing_channel = channel;
1451                                         goto found_channel;
1452                                 }
1453                         }
1454
1455                         /*
1456                          * All the other channels on the same NUMA node are
1457                          * busy. Try to use the channel on the current CPU
1458                          */
1459                         if (hv_get_avail_to_write_percent(
1460                                                 &outgoing_channel->outbound)
1461                                         > ring_avail_percent_lowater)
1462                                 goto found_channel;
1463
1464                         /*
1465                          * If we reach here, all the channels on the current
1466                          * NUMA node are busy. Try to find a channel in
1467                          * other NUMA nodes
1468                          */
1469                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1470                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1471                                         continue;
1472                                 channel = READ_ONCE(
1473                                         stor_device->stor_chns[tgt_cpu]);
1474                                 if (channel == NULL)
1475                                         continue;
1476                                 if (hv_get_avail_to_write_percent(
1477                                                         &channel->outbound)
1478                                                 > ring_avail_percent_lowater) {
1479                                         outgoing_channel = channel;
1480                                         goto found_channel;
1481                                 }
1482                         }
1483                 }
1484         } else {
1485                 spin_lock_irqsave(&stor_device->lock, flags);
1486                 outgoing_channel = stor_device->stor_chns[q_num];
1487                 if (outgoing_channel != NULL) {
1488                         spin_unlock_irqrestore(&stor_device->lock, flags);
1489                         goto found_channel;
1490                 }
1491                 outgoing_channel = get_og_chn(stor_device, q_num);
1492                 spin_unlock_irqrestore(&stor_device->lock, flags);
1493         }
1494
1495 found_channel:
1496         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1497
1498         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1499                                         stor_device->vmscsi_size_delta);
1500
1501
1502         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1503
1504
1505         vstor_packet->vm_srb.data_transfer_length =
1506         request->payload->range.len;
1507
1508         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1509
1510         if (request->payload->range.len) {
1511
1512                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1513                                 request->payload, request->payload_sz,
1514                                 vstor_packet,
1515                                 (sizeof(struct vstor_packet) -
1516                                 stor_device->vmscsi_size_delta),
1517                                 (unsigned long)request);
1518         } else {
1519                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1520                                (sizeof(struct vstor_packet) -
1521                                 stor_device->vmscsi_size_delta),
1522                                (unsigned long)request,
1523                                VM_PKT_DATA_INBAND,
1524                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1525         }
1526
1527         if (ret != 0)
1528                 return ret;
1529
1530         atomic_inc(&stor_device->num_outstanding_req);
1531
1532         return ret;
1533 }
1534
1535 static int storvsc_device_alloc(struct scsi_device *sdevice)
1536 {
1537         /*
1538          * Set blist flag to permit the reading of the VPD pages even when
1539          * the target may claim SPC-2 compliance. MSFT targets currently
1540          * claim SPC-2 compliance while they implement post SPC-2 features.
1541          * With this flag we can correctly handle WRITE_SAME_16 issues.
1542          *
1543          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1544          * still supports REPORT LUN.
1545          */
1546         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1547
1548         return 0;
1549 }
1550
1551 static int storvsc_device_configure(struct scsi_device *sdevice)
1552 {
1553         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1554
1555         sdevice->no_write_same = 1;
1556
1557         /*
1558          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1559          * if the device is a MSFT virtual device.  If the host is
1560          * WIN10 or newer, allow write_same.
1561          */
1562         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1563                 switch (vmstor_proto_version) {
1564                 case VMSTOR_PROTO_VERSION_WIN8:
1565                 case VMSTOR_PROTO_VERSION_WIN8_1:
1566                         sdevice->scsi_level = SCSI_SPC_3;
1567                         break;
1568                 }
1569
1570                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1571                         sdevice->no_write_same = 0;
1572         }
1573
1574         return 0;
1575 }
1576
1577 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1578                            sector_t capacity, int *info)
1579 {
1580         sector_t nsect = capacity;
1581         sector_t cylinders = nsect;
1582         int heads, sectors_pt;
1583
1584         /*
1585          * We are making up these values; let us keep it simple.
1586          */
1587         heads = 0xff;
1588         sectors_pt = 0x3f;      /* Sectors per track */
1589         sector_div(cylinders, heads * sectors_pt);
1590         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1591                 cylinders = 0xffff;
1592
1593         info[0] = heads;
1594         info[1] = sectors_pt;
1595         info[2] = (int)cylinders;
1596
1597         return 0;
1598 }
1599
1600 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1601 {
1602         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1603         struct hv_device *device = host_dev->dev;
1604
1605         struct storvsc_device *stor_device;
1606         struct storvsc_cmd_request *request;
1607         struct vstor_packet *vstor_packet;
1608         int ret, t;
1609
1610         stor_device = get_out_stor_device(device);
1611         if (!stor_device)
1612                 return FAILED;
1613
1614         request = &stor_device->reset_request;
1615         vstor_packet = &request->vstor_packet;
1616         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1617
1618         init_completion(&request->wait_event);
1619
1620         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1621         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1622         vstor_packet->vm_srb.path_id = stor_device->path_id;
1623
1624         ret = vmbus_sendpacket(device->channel, vstor_packet,
1625                                (sizeof(struct vstor_packet) -
1626                                 stor_device->vmscsi_size_delta),
1627                                (unsigned long)&stor_device->reset_request,
1628                                VM_PKT_DATA_INBAND,
1629                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1630         if (ret != 0)
1631                 return FAILED;
1632
1633         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1634         if (t == 0)
1635                 return TIMEOUT_ERROR;
1636
1637
1638         /*
1639          * At this point, all outstanding requests in the adapter
1640          * should have been flushed out and return to us
1641          * There is a potential race here where the host may be in
1642          * the process of responding when we return from here.
1643          * Just wait for all in-transit packets to be accounted for
1644          * before we return from here.
1645          */
1646         storvsc_wait_to_drain(stor_device);
1647
1648         return SUCCESS;
1649 }
1650
1651 /*
1652  * The host guarantees to respond to each command, although I/O latencies might
1653  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1654  * chance to perform EH.
1655  */
1656 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1657 {
1658 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1659         if (scmnd->device->host->transportt == fc_transport_template)
1660                 return fc_eh_timed_out(scmnd);
1661 #endif
1662         return BLK_EH_RESET_TIMER;
1663 }
1664
1665 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1666 {
1667         bool allowed = true;
1668         u8 scsi_op = scmnd->cmnd[0];
1669
1670         switch (scsi_op) {
1671         /* the host does not handle WRITE_SAME, log accident usage */
1672         case WRITE_SAME:
1673         /*
1674          * smartd sends this command and the host does not handle
1675          * this. So, don't send it.
1676          */
1677         case SET_WINDOW:
1678                 scmnd->result = DID_ERROR << 16;
1679                 allowed = false;
1680                 break;
1681         default:
1682                 break;
1683         }
1684         return allowed;
1685 }
1686
1687 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1688 {
1689         int ret;
1690         struct hv_host_device *host_dev = shost_priv(host);
1691         struct hv_device *dev = host_dev->dev;
1692         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1693         int i;
1694         struct scatterlist *sgl;
1695         unsigned int sg_count;
1696         struct vmscsi_request *vm_srb;
1697         struct vmbus_packet_mpb_array  *payload;
1698         u32 payload_sz;
1699         u32 length;
1700
1701         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1702                 /*
1703                  * On legacy hosts filter unimplemented commands.
1704                  * Future hosts are expected to correctly handle
1705                  * unsupported commands. Furthermore, it is
1706                  * possible that some of the currently
1707                  * unsupported commands maybe supported in
1708                  * future versions of the host.
1709                  */
1710                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1711                         scmnd->scsi_done(scmnd);
1712                         return 0;
1713                 }
1714         }
1715
1716         /* Setup the cmd request */
1717         cmd_request->cmd = scmnd;
1718
1719         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1720         vm_srb = &cmd_request->vstor_packet.vm_srb;
1721         vm_srb->win8_extension.time_out_value = 60;
1722
1723         vm_srb->win8_extension.srb_flags |=
1724                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1725
1726         if (scmnd->device->tagged_supported) {
1727                 vm_srb->win8_extension.srb_flags |=
1728                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1729                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1730                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1731         }
1732
1733         /* Build the SRB */
1734         switch (scmnd->sc_data_direction) {
1735         case DMA_TO_DEVICE:
1736                 vm_srb->data_in = WRITE_TYPE;
1737                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1738                 break;
1739         case DMA_FROM_DEVICE:
1740                 vm_srb->data_in = READ_TYPE;
1741                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1742                 break;
1743         case DMA_NONE:
1744                 vm_srb->data_in = UNKNOWN_TYPE;
1745                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1746                 break;
1747         default:
1748                 /*
1749                  * This is DMA_BIDIRECTIONAL or something else we are never
1750                  * supposed to see here.
1751                  */
1752                 WARN(1, "Unexpected data direction: %d\n",
1753                      scmnd->sc_data_direction);
1754                 return -EINVAL;
1755         }
1756
1757
1758         vm_srb->port_number = host_dev->port;
1759         vm_srb->path_id = scmnd->device->channel;
1760         vm_srb->target_id = scmnd->device->id;
1761         vm_srb->lun = scmnd->device->lun;
1762
1763         vm_srb->cdb_length = scmnd->cmd_len;
1764
1765         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1766
1767         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1768         sg_count = scsi_sg_count(scmnd);
1769
1770         length = scsi_bufflen(scmnd);
1771         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1772         payload_sz = sizeof(cmd_request->mpb);
1773
1774         if (sg_count) {
1775                 unsigned int hvpgoff, hvpfns_to_add;
1776                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1777                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1778                 u64 hvpfn;
1779
1780                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1781
1782                         payload_sz = (hvpg_count * sizeof(u64) +
1783                                       sizeof(struct vmbus_packet_mpb_array));
1784                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1785                         if (!payload)
1786                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1787                 }
1788
1789                 payload->range.len = length;
1790                 payload->range.offset = offset_in_hvpg;
1791
1792
1793                 for (i = 0; sgl != NULL; sgl = sg_next(sgl)) {
1794                         /*
1795                          * Init values for the current sgl entry. hvpgoff
1796                          * and hvpfns_to_add are in units of Hyper-V size
1797                          * pages. Handling the PAGE_SIZE != HV_HYP_PAGE_SIZE
1798                          * case also handles values of sgl->offset that are
1799                          * larger than PAGE_SIZE. Such offsets are handled
1800                          * even on other than the first sgl entry, provided
1801                          * they are a multiple of PAGE_SIZE.
1802                          */
1803                         hvpgoff = HVPFN_DOWN(sgl->offset);
1804                         hvpfn = page_to_hvpfn(sg_page(sgl)) + hvpgoff;
1805                         hvpfns_to_add = HVPFN_UP(sgl->offset + sgl->length) -
1806                                                 hvpgoff;
1807
1808                         /*
1809                          * Fill the next portion of the PFN array with
1810                          * sequential Hyper-V PFNs for the continguous physical
1811                          * memory described by the sgl entry. The end of the
1812                          * last sgl should be reached at the same time that
1813                          * the PFN array is filled.
1814                          */
1815                         while (hvpfns_to_add--)
1816                                 payload->range.pfn_array[i++] = hvpfn++;
1817                 }
1818         }
1819
1820         cmd_request->payload = payload;
1821         cmd_request->payload_sz = payload_sz;
1822
1823         /* Invokes the vsc to start an IO */
1824         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1825         put_cpu();
1826
1827         if (ret == -EAGAIN) {
1828                 if (payload_sz > sizeof(cmd_request->mpb))
1829                         kfree(payload);
1830                 /* no more space */
1831                 return SCSI_MLQUEUE_DEVICE_BUSY;
1832         }
1833
1834         return 0;
1835 }
1836
1837 static struct scsi_host_template scsi_driver = {
1838         .module =               THIS_MODULE,
1839         .name =                 "storvsc_host_t",
1840         .cmd_size =             sizeof(struct storvsc_cmd_request),
1841         .bios_param =           storvsc_get_chs,
1842         .queuecommand =         storvsc_queuecommand,
1843         .eh_host_reset_handler =        storvsc_host_reset_handler,
1844         .proc_name =            "storvsc_host",
1845         .eh_timed_out =         storvsc_eh_timed_out,
1846         .slave_alloc =          storvsc_device_alloc,
1847         .slave_configure =      storvsc_device_configure,
1848         .cmd_per_lun =          2048,
1849         .this_id =              -1,
1850         /* Ensure there are no gaps in presented sgls */
1851         .virt_boundary_mask =   PAGE_SIZE-1,
1852         .no_write_same =        1,
1853         .track_queue_depth =    1,
1854         .change_queue_depth =   storvsc_change_queue_depth,
1855 };
1856
1857 enum {
1858         SCSI_GUID,
1859         IDE_GUID,
1860         SFC_GUID,
1861 };
1862
1863 static const struct hv_vmbus_device_id id_table[] = {
1864         /* SCSI guid */
1865         { HV_SCSI_GUID,
1866           .driver_data = SCSI_GUID
1867         },
1868         /* IDE guid */
1869         { HV_IDE_GUID,
1870           .driver_data = IDE_GUID
1871         },
1872         /* Fibre Channel GUID */
1873         {
1874           HV_SYNTHFC_GUID,
1875           .driver_data = SFC_GUID
1876         },
1877         { },
1878 };
1879
1880 MODULE_DEVICE_TABLE(vmbus, id_table);
1881
1882 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1883
1884 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1885 {
1886         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1887 }
1888
1889 static int storvsc_probe(struct hv_device *device,
1890                         const struct hv_vmbus_device_id *dev_id)
1891 {
1892         int ret;
1893         int num_cpus = num_online_cpus();
1894         int num_present_cpus = num_present_cpus();
1895         struct Scsi_Host *host;
1896         struct hv_host_device *host_dev;
1897         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1898         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1899         int target = 0;
1900         struct storvsc_device *stor_device;
1901         int max_luns_per_target;
1902         int max_targets;
1903         int max_channels;
1904         int max_sub_channels = 0;
1905
1906         /*
1907          * Based on the windows host we are running on,
1908          * set state to properly communicate with the host.
1909          */
1910
1911         if (vmbus_proto_version < VERSION_WIN8) {
1912                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1913                 max_targets = STORVSC_IDE_MAX_TARGETS;
1914                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1915         } else {
1916                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1917                 max_targets = STORVSC_MAX_TARGETS;
1918                 max_channels = STORVSC_MAX_CHANNELS;
1919                 /*
1920                  * On Windows8 and above, we support sub-channels for storage
1921                  * on SCSI and FC controllers.
1922                  * The number of sub-channels offerred is based on the number of
1923                  * VCPUs in the guest.
1924                  */
1925                 if (!dev_is_ide)
1926                         max_sub_channels =
1927                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1928         }
1929
1930         scsi_driver.can_queue = max_outstanding_req_per_channel *
1931                                 (max_sub_channels + 1) *
1932                                 (100 - ring_avail_percent_lowater) / 100;
1933
1934         host = scsi_host_alloc(&scsi_driver,
1935                                sizeof(struct hv_host_device));
1936         if (!host)
1937                 return -ENOMEM;
1938
1939         host_dev = shost_priv(host);
1940         memset(host_dev, 0, sizeof(struct hv_host_device));
1941
1942         host_dev->port = host->host_no;
1943         host_dev->dev = device;
1944         host_dev->host = host;
1945
1946
1947         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1948         if (!stor_device) {
1949                 ret = -ENOMEM;
1950                 goto err_out0;
1951         }
1952
1953         stor_device->destroy = false;
1954         init_waitqueue_head(&stor_device->waiting_to_drain);
1955         stor_device->device = device;
1956         stor_device->host = host;
1957         stor_device->vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1958         spin_lock_init(&stor_device->lock);
1959         hv_set_drvdata(device, stor_device);
1960
1961         stor_device->port_number = host->host_no;
1962         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1963         if (ret)
1964                 goto err_out1;
1965
1966         host_dev->path = stor_device->path_id;
1967         host_dev->target = stor_device->target_id;
1968
1969         switch (dev_id->driver_data) {
1970         case SFC_GUID:
1971                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1972                 host->max_id = STORVSC_FC_MAX_TARGETS;
1973                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1974 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1975                 host->transportt = fc_transport_template;
1976 #endif
1977                 break;
1978
1979         case SCSI_GUID:
1980                 host->max_lun = max_luns_per_target;
1981                 host->max_id = max_targets;
1982                 host->max_channel = max_channels - 1;
1983                 break;
1984
1985         default:
1986                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1987                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1988                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1989                 break;
1990         }
1991         /* max cmd length */
1992         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1993
1994         /*
1995          * set the table size based on the info we got
1996          * from the host.
1997          */
1998         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1999         /*
2000          * For non-IDE disks, the host supports multiple channels.
2001          * Set the number of HW queues we are supporting.
2002          */
2003         if (!dev_is_ide) {
2004                 if (storvsc_max_hw_queues > num_present_cpus) {
2005                         storvsc_max_hw_queues = 0;
2006                         storvsc_log(device, STORVSC_LOGGING_WARN,
2007                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2008                 }
2009                 if (storvsc_max_hw_queues)
2010                         host->nr_hw_queues = storvsc_max_hw_queues;
2011                 else
2012                         host->nr_hw_queues = num_present_cpus;
2013         }
2014
2015         /*
2016          * Set the error handler work queue.
2017          */
2018         host_dev->handle_error_wq =
2019                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2020                                                 WQ_MEM_RECLAIM,
2021                                                 host->host_no);
2022         if (!host_dev->handle_error_wq) {
2023                 ret = -ENOMEM;
2024                 goto err_out2;
2025         }
2026         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2027         /* Register the HBA and start the scsi bus scan */
2028         ret = scsi_add_host(host, &device->device);
2029         if (ret != 0)
2030                 goto err_out3;
2031
2032         if (!dev_is_ide) {
2033                 scsi_scan_host(host);
2034         } else {
2035                 target = (device->dev_instance.b[5] << 8 |
2036                          device->dev_instance.b[4]);
2037                 ret = scsi_add_device(host, 0, target, 0);
2038                 if (ret)
2039                         goto err_out4;
2040         }
2041 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2042         if (host->transportt == fc_transport_template) {
2043                 struct fc_rport_identifiers ids = {
2044                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2045                 };
2046
2047                 fc_host_node_name(host) = stor_device->node_name;
2048                 fc_host_port_name(host) = stor_device->port_name;
2049                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2050                 if (!stor_device->rport) {
2051                         ret = -ENOMEM;
2052                         goto err_out4;
2053                 }
2054         }
2055 #endif
2056         return 0;
2057
2058 err_out4:
2059         scsi_remove_host(host);
2060
2061 err_out3:
2062         destroy_workqueue(host_dev->handle_error_wq);
2063
2064 err_out2:
2065         /*
2066          * Once we have connected with the host, we would need to
2067          * to invoke storvsc_dev_remove() to rollback this state and
2068          * this call also frees up the stor_device; hence the jump around
2069          * err_out1 label.
2070          */
2071         storvsc_dev_remove(device);
2072         goto err_out0;
2073
2074 err_out1:
2075         kfree(stor_device->stor_chns);
2076         kfree(stor_device);
2077
2078 err_out0:
2079         scsi_host_put(host);
2080         return ret;
2081 }
2082
2083 /* Change a scsi target's queue depth */
2084 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2085 {
2086         if (queue_depth > scsi_driver.can_queue)
2087                 queue_depth = scsi_driver.can_queue;
2088
2089         return scsi_change_queue_depth(sdev, queue_depth);
2090 }
2091
2092 static int storvsc_remove(struct hv_device *dev)
2093 {
2094         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2095         struct Scsi_Host *host = stor_device->host;
2096         struct hv_host_device *host_dev = shost_priv(host);
2097
2098 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2099         if (host->transportt == fc_transport_template) {
2100                 fc_remote_port_delete(stor_device->rport);
2101                 fc_remove_host(host);
2102         }
2103 #endif
2104         destroy_workqueue(host_dev->handle_error_wq);
2105         scsi_remove_host(host);
2106         storvsc_dev_remove(dev);
2107         scsi_host_put(host);
2108
2109         return 0;
2110 }
2111
2112 static int storvsc_suspend(struct hv_device *hv_dev)
2113 {
2114         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2115         struct Scsi_Host *host = stor_device->host;
2116         struct hv_host_device *host_dev = shost_priv(host);
2117
2118         storvsc_wait_to_drain(stor_device);
2119
2120         drain_workqueue(host_dev->handle_error_wq);
2121
2122         vmbus_close(hv_dev->channel);
2123
2124         kfree(stor_device->stor_chns);
2125         stor_device->stor_chns = NULL;
2126
2127         cpumask_clear(&stor_device->alloced_cpus);
2128
2129         return 0;
2130 }
2131
2132 static int storvsc_resume(struct hv_device *hv_dev)
2133 {
2134         int ret;
2135
2136         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2137                                      hv_dev_is_fc(hv_dev));
2138         return ret;
2139 }
2140
2141 static struct hv_driver storvsc_drv = {
2142         .name = KBUILD_MODNAME,
2143         .id_table = id_table,
2144         .probe = storvsc_probe,
2145         .remove = storvsc_remove,
2146         .suspend = storvsc_suspend,
2147         .resume = storvsc_resume,
2148         .driver = {
2149                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2150         },
2151 };
2152
2153 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2154 static struct fc_function_template fc_transport_functions = {
2155         .show_host_node_name = 1,
2156         .show_host_port_name = 1,
2157 };
2158 #endif
2159
2160 static int __init storvsc_drv_init(void)
2161 {
2162         int ret;
2163
2164         /*
2165          * Divide the ring buffer data size (which is 1 page less
2166          * than the ring buffer size since that page is reserved for
2167          * the ring buffer indices) by the max request size (which is
2168          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2169          *
2170          * The computation underestimates max_outstanding_req_per_channel
2171          * for Win7 and older hosts because it does not take into account
2172          * the vmscsi_size_delta correction to the max request size.
2173          */
2174         max_outstanding_req_per_channel =
2175                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2176                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2177                 sizeof(struct vstor_packet) + sizeof(u64),
2178                 sizeof(u64)));
2179
2180 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2181         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2182         if (!fc_transport_template)
2183                 return -ENODEV;
2184 #endif
2185
2186         ret = vmbus_driver_register(&storvsc_drv);
2187
2188 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2189         if (ret)
2190                 fc_release_transport(fc_transport_template);
2191 #endif
2192
2193         return ret;
2194 }
2195
2196 static void __exit storvsc_drv_exit(void)
2197 {
2198         vmbus_driver_unregister(&storvsc_drv);
2199 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2200         fc_release_transport(fc_transport_template);
2201 #endif
2202 }
2203
2204 MODULE_LICENSE("GPL");
2205 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2206 module_init(storvsc_drv_init);
2207 module_exit(storvsc_drv_exit);