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_TIMEOUT              0x09
 320 #define SRB_STATUS_SELECTION_TIMEOUT    0x0A
 321 #define SRB_STATUS_BUS_RESET            0x0E
 322 #define SRB_STATUS_DATA_OVERRUN         0x12
 323 #define SRB_STATUS_INVALID_LUN          0x20
 324 #define SRB_STATUS_INTERNAL_ERROR       0x30
 325
 326 #define SRB_STATUS(status) \
 327         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 328 /*
 329  * This is the end of Protocol specific defines.
 330  */
 331
 332 static int storvsc_ringbuffer_size = (128 * 1024);
 333 static int aligned_ringbuffer_size;
 334 static u32 max_outstanding_req_per_channel;
 335 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 336
 337 static int storvsc_vcpus_per_sub_channel = 4;
 338 static unsigned int storvsc_max_hw_queues;
 339
 340 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 341 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 342
 343 module_param(storvsc_max_hw_queues, uint, 0644);
 344 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
 345
 346 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 347 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 348
 349 static int ring_avail_percent_lowater = 10;
 350 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 351 MODULE_PARM_DESC(ring_avail_percent_lowater,
 352                 "Select a channel if available ring size > this in percent");
 353
 354 /*
 355  * Timeout in seconds for all devices managed by this driver.
 356  */
 357 static int storvsc_timeout = 180;
 358
 359 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 360 static struct scsi_transport_template *fc_transport_template;
 361 #endif
 362
 363 static struct scsi_host_template scsi_driver;
 364 static void storvsc_on_channel_callback(void *context);
 365
 366 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 367 #define STORVSC_MAX_TARGETS                             2
 368 #define STORVSC_MAX_CHANNELS                            8
 369
 370 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 371 #define STORVSC_FC_MAX_TARGETS                          128
 372 #define STORVSC_FC_MAX_CHANNELS                         8
 373 #define STORVSC_FC_MAX_XFER_SIZE                        ((u32)(512 * 1024))
 374
 375 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 376 #define STORVSC_IDE_MAX_TARGETS                         1
 377 #define STORVSC_IDE_MAX_CHANNELS                        1
 378
 379 /*
 380  * Upper bound on the size of a storvsc packet.
 381  */
 382 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
 383                               sizeof(struct vstor_packet))
 384
 385 struct storvsc_cmd_request {
 386         struct scsi_cmnd *cmd;
 387
 388         struct hv_device *device;
 389
 390         /* Synchronize the request/response if needed */
 391         struct completion wait_event;
 392
 393         struct vmbus_channel_packet_multipage_buffer mpb;
 394         struct vmbus_packet_mpb_array *payload;
 395         u32 payload_sz;
 396
 397         struct vstor_packet vstor_packet;
 398 };
 399
 400
 401 /* A storvsc device is a device object that contains a vmbus channel */
 402 struct storvsc_device {
 403         struct hv_device *device;
 404
 405         bool     destroy;
 406         bool     drain_notify;
 407         atomic_t num_outstanding_req;
 408         struct Scsi_Host *host;
 409
 410         wait_queue_head_t waiting_to_drain;
 411
 412         /*
 413          * Each unique Port/Path/Target represents 1 channel ie scsi
 414          * controller. In reality, the pathid, targetid is always 0
 415          * and the port is set by us
 416          */
 417         unsigned int port_number;
 418         unsigned char path_id;
 419         unsigned char target_id;
 420
 421         /*
 422          * Max I/O, the device can support.
 423          */
 424         u32   max_transfer_bytes;
 425         /*
 426          * Number of sub-channels we will open.
 427          */
 428         u16 num_sc;
 429         struct vmbus_channel **stor_chns;
 430         /*
 431          * Mask of CPUs bound to subchannels.
 432          */
 433         struct cpumask alloced_cpus;
 434         /*
 435          * Serializes modifications of stor_chns[] from storvsc_do_io()
 436          * and storvsc_change_target_cpu().
 437          */
 438         spinlock_t lock;
 439         /* Used for vsc/vsp channel reset process */
 440         struct storvsc_cmd_request init_request;
 441         struct storvsc_cmd_request reset_request;
 442         /*
 443          * Currently active port and node names for FC devices.
 444          */
 445         u64 node_name;
 446         u64 port_name;
 447 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 448         struct fc_rport *rport;
 449 #endif
 450 };
 451
 452 struct hv_host_device {
 453         struct hv_device *dev;
 454         unsigned int port;
 455         unsigned char path;
 456         unsigned char target;
 457         struct workqueue_struct *handle_error_wq;
 458         struct work_struct host_scan_work;
 459         struct Scsi_Host *host;
 460 };
 461
 462 struct storvsc_scan_work {
 463         struct work_struct work;
 464         struct Scsi_Host *host;
 465         u8 lun;
 466         u8 tgt_id;
 467 };
 468
 469 static void storvsc_device_scan(struct work_struct *work)
 470 {
 471         struct storvsc_scan_work *wrk;
 472         struct scsi_device *sdev;
 473
 474         wrk = container_of(work, struct storvsc_scan_work, work);
 475
 476         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 477         if (!sdev)
 478                 goto done;
 479         scsi_rescan_device(sdev);
 480         scsi_device_put(sdev);
 481
 482 done:
 483         kfree(wrk);
 484 }
 485
 486 static void storvsc_host_scan(struct work_struct *work)
 487 {
 488         struct Scsi_Host *host;
 489         struct scsi_device *sdev;
 490         struct hv_host_device *host_device =
 491                 container_of(work, struct hv_host_device, host_scan_work);
 492
 493         host = host_device->host;
 494         /*
 495          * Before scanning the host, first check to see if any of the
 496          * currently known devices have been hot removed. We issue a
 497          * "unit ready" command against all currently known devices.
 498          * This I/O will result in an error for devices that have been
 499          * removed. As part of handling the I/O error, we remove the device.
 500          *
 501          * When a LUN is added or removed, the host sends us a signal to
 502          * scan the host. Thus we are forced to discover the LUNs that
 503          * may have been removed this way.
 504          */
 505         mutex_lock(&host->scan_mutex);
 506         shost_for_each_device(sdev, host)
 507                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 508         mutex_unlock(&host->scan_mutex);
 509         /*
 510          * Now scan the host to discover LUNs that may have been added.
 511          */
 512         scsi_scan_host(host);
 513 }
 514
 515 static void storvsc_remove_lun(struct work_struct *work)
 516 {
 517         struct storvsc_scan_work *wrk;
 518         struct scsi_device *sdev;
 519
 520         wrk = container_of(work, struct storvsc_scan_work, work);
 521         if (!scsi_host_get(wrk->host))
 522                 goto done;
 523
 524         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 525
 526         if (sdev) {
 527                 scsi_remove_device(sdev);
 528                 scsi_device_put(sdev);
 529         }
 530         scsi_host_put(wrk->host);
 531
 532 done:
 533         kfree(wrk);
 534 }
 535
 536
 537 /*
 538  * We can get incoming messages from the host that are not in response to
 539  * messages that we have sent out. An example of this would be messages
 540  * received by the guest to notify dynamic addition/removal of LUNs. To
 541  * deal with potential race conditions where the driver may be in the
 542  * midst of being unloaded when we might receive an unsolicited message
 543  * from the host, we have implemented a mechanism to gurantee sequential
 544  * consistency:
 545  *
 546  * 1) Once the device is marked as being destroyed, we will fail all
 547  *    outgoing messages.
 548  * 2) We permit incoming messages when the device is being destroyed,
 549  *    only to properly account for messages already sent out.
 550  */
 551
 552 static inline struct storvsc_device *get_out_stor_device(
 553                                         struct hv_device *device)
 554 {
 555         struct storvsc_device *stor_device;
 556
 557         stor_device = hv_get_drvdata(device);
 558
 559         if (stor_device && stor_device->destroy)
 560                 stor_device = NULL;
 561
 562         return stor_device;
 563 }
 564
 565
 566 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 567 {
 568         dev->drain_notify = true;
 569         wait_event(dev->waiting_to_drain,
 570                    atomic_read(&dev->num_outstanding_req) == 0);
 571         dev->drain_notify = false;
 572 }
 573
 574 static inline struct storvsc_device *get_in_stor_device(
 575                                         struct hv_device *device)
 576 {
 577         struct storvsc_device *stor_device;
 578
 579         stor_device = hv_get_drvdata(device);
 580
 581         if (!stor_device)
 582                 goto get_in_err;
 583
 584         /*
 585          * If the device is being destroyed; allow incoming
 586          * traffic only to cleanup outstanding requests.
 587          */
 588
 589         if (stor_device->destroy  &&
 590                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 591                 stor_device = NULL;
 592
 593 get_in_err:
 594         return stor_device;
 595
 596 }
 597
 598 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 599                                       u32 new)
 600 {
 601         struct storvsc_device *stor_device;
 602         struct vmbus_channel *cur_chn;
 603         bool old_is_alloced = false;
 604         struct hv_device *device;
 605         unsigned long flags;
 606         int cpu;
 607
 608         device = channel->primary_channel ?
 609                         channel->primary_channel->device_obj
 610                                 : channel->device_obj;
 611         stor_device = get_out_stor_device(device);
 612         if (!stor_device)
 613                 return;
 614
 615         /* See storvsc_do_io() -> get_og_chn(). */
 616         spin_lock_irqsave(&stor_device->lock, flags);
 617
 618         /*
 619          * Determines if the storvsc device has other channels assigned to
 620          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 621          * array.
 622          */
 623         if (device->channel != channel && device->channel->target_cpu == old) {
 624                 cur_chn = device->channel;
 625                 old_is_alloced = true;
 626                 goto old_is_alloced;
 627         }
 628         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 629                 if (cur_chn == channel)
 630                         continue;
 631                 if (cur_chn->target_cpu == old) {
 632                         old_is_alloced = true;
 633                         goto old_is_alloced;
 634                 }
 635         }
 636
 637 old_is_alloced:
 638         if (old_is_alloced)
 639                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 640         else
 641                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 642
 643         /* "Flush" the stor_chns array. */
 644         for_each_possible_cpu(cpu) {
 645                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 646                                         cpu, &stor_device->alloced_cpus))
 647                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 648         }
 649
 650         WRITE_ONCE(stor_device->stor_chns[new], channel);
 651         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 652
 653         spin_unlock_irqrestore(&stor_device->lock, flags);
 654 }
 655
 656 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 657 {
 658         struct storvsc_cmd_request *request =
 659                 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
 660
 661         if (rqst_addr == VMBUS_RQST_INIT)
 662                 return VMBUS_RQST_INIT;
 663         if (rqst_addr == VMBUS_RQST_RESET)
 664                 return VMBUS_RQST_RESET;
 665
 666         /*
 667          * Cannot return an ID of 0, which is reserved for an unsolicited
 668          * message from Hyper-V.
 669          */
 670         return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
 671 }
 672
 673 static void handle_sc_creation(struct vmbus_channel *new_sc)
 674 {
 675         struct hv_device *device = new_sc->primary_channel->device_obj;
 676         struct device *dev = &device->device;
 677         struct storvsc_device *stor_device;
 678         struct vmstorage_channel_properties props;
 679         int ret;
 680
 681         stor_device = get_out_stor_device(device);
 682         if (!stor_device)
 683                 return;
 684
 685         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 686         new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
 687
 688         new_sc->next_request_id_callback = storvsc_next_request_id;
 689
 690         ret = vmbus_open(new_sc,
 691                          aligned_ringbuffer_size,
 692                          aligned_ringbuffer_size,
 693                          (void *)&props,
 694                          sizeof(struct vmstorage_channel_properties),
 695                          storvsc_on_channel_callback, new_sc);
 696
 697         /* In case vmbus_open() fails, we don't use the sub-channel. */
 698         if (ret != 0) {
 699                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 700                 return;
 701         }
 702
 703         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 704
 705         /* Add the sub-channel to the array of available channels. */
 706         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 707         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 708 }
 709
 710 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 711 {
 712         struct device *dev = &device->device;
 713         struct storvsc_device *stor_device;
 714         int num_sc;
 715         struct storvsc_cmd_request *request;
 716         struct vstor_packet *vstor_packet;
 717         int ret, t;
 718
 719         /*
 720          * If the number of CPUs is artificially restricted, such as
 721          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 722          * sub-channels >= the number of CPUs. These sub-channels
 723          * should not be created. The primary channel is already created
 724          * and assigned to one CPU, so check against # CPUs - 1.
 725          */
 726         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 727         if (!num_sc)
 728                 return;
 729
 730         stor_device = get_out_stor_device(device);
 731         if (!stor_device)
 732                 return;
 733
 734         stor_device->num_sc = num_sc;
 735         request = &stor_device->init_request;
 736         vstor_packet = &request->vstor_packet;
 737
 738         /*
 739          * Establish a handler for dealing with subchannels.
 740          */
 741         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 742
 743         /*
 744          * Request the host to create sub-channels.
 745          */
 746         memset(request, 0, sizeof(struct storvsc_cmd_request));
 747         init_completion(&request->wait_event);
 748         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 749         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 750         vstor_packet->sub_channel_count = num_sc;
 751
 752         ret = vmbus_sendpacket(device->channel, vstor_packet,
 753                                sizeof(struct vstor_packet),
 754                                VMBUS_RQST_INIT,
 755                                VM_PKT_DATA_INBAND,
 756                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 757
 758         if (ret != 0) {
 759                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 760                 return;
 761         }
 762
 763         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 764         if (t == 0) {
 765                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 766                 return;
 767         }
 768
 769         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 770             vstor_packet->status != 0) {
 771                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 772                         vstor_packet->operation, vstor_packet->status);
 773                 return;
 774         }
 775
 776         /*
 777          * We need to do nothing here, because vmbus_process_offer()
 778          * invokes channel->sc_creation_callback, which will open and use
 779          * the sub-channel(s).
 780          */
 781 }
 782
 783 static void cache_wwn(struct storvsc_device *stor_device,
 784                       struct vstor_packet *vstor_packet)
 785 {
 786         /*
 787          * Cache the currently active port and node ww names.
 788          */
 789         if (vstor_packet->wwn_packet.primary_active) {
 790                 stor_device->node_name =
 791                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 792                 stor_device->port_name =
 793                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 794         } else {
 795                 stor_device->node_name =
 796                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 797                 stor_device->port_name =
 798                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 799         }
 800 }
 801
 802
 803 static int storvsc_execute_vstor_op(struct hv_device *device,
 804                                     struct storvsc_cmd_request *request,
 805                                     bool status_check)
 806 {
 807         struct storvsc_device *stor_device;
 808         struct vstor_packet *vstor_packet;
 809         int ret, t;
 810
 811         stor_device = get_out_stor_device(device);
 812         if (!stor_device)
 813                 return -ENODEV;
 814
 815         vstor_packet = &request->vstor_packet;
 816
 817         init_completion(&request->wait_event);
 818         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 819
 820         ret = vmbus_sendpacket(device->channel, vstor_packet,
 821                                sizeof(struct vstor_packet),
 822                                VMBUS_RQST_INIT,
 823                                VM_PKT_DATA_INBAND,
 824                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 825         if (ret != 0)
 826                 return ret;
 827
 828         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 829         if (t == 0)
 830                 return -ETIMEDOUT;
 831
 832         if (!status_check)
 833                 return ret;
 834
 835         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 836             vstor_packet->status != 0)
 837                 return -EINVAL;
 838
 839         return ret;
 840 }
 841
 842 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 843 {
 844         struct storvsc_device *stor_device;
 845         struct storvsc_cmd_request *request;
 846         struct vstor_packet *vstor_packet;
 847         int ret, i;
 848         int max_chns;
 849         bool process_sub_channels = false;
 850
 851         stor_device = get_out_stor_device(device);
 852         if (!stor_device)
 853                 return -ENODEV;
 854
 855         request = &stor_device->init_request;
 856         vstor_packet = &request->vstor_packet;
 857
 858         /*
 859          * Now, initiate the vsc/vsp initialization protocol on the open
 860          * channel
 861          */
 862         memset(request, 0, sizeof(struct storvsc_cmd_request));
 863         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 864         ret = storvsc_execute_vstor_op(device, request, true);
 865         if (ret)
 866                 return ret;
 867         /*
 868          * Query host supported protocol version.
 869          */
 870
 871         for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
 872                 /* reuse the packet for version range supported */
 873                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 874                 vstor_packet->operation =
 875                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 876
 877                 vstor_packet->version.major_minor = protocol_version[i];
 878
 879                 /*
 880                  * The revision number is only used in Windows; set it to 0.
 881                  */
 882                 vstor_packet->version.revision = 0;
 883                 ret = storvsc_execute_vstor_op(device, request, false);
 884                 if (ret != 0)
 885                         return ret;
 886
 887                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 888                         return -EINVAL;
 889
 890                 if (vstor_packet->status == 0) {
 891                         vmstor_proto_version = protocol_version[i];
 892
 893                         break;
 894                 }
 895         }
 896
 897         if (vstor_packet->status != 0) {
 898                 dev_err(&device->device, "Obsolete Hyper-V version\n");
 899                 return -EINVAL;
 900         }
 901
 902
 903         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 904         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 905         ret = storvsc_execute_vstor_op(device, request, true);
 906         if (ret != 0)
 907                 return ret;
 908
 909         /*
 910          * Check to see if multi-channel support is there.
 911          * Hosts that implement protocol version of 5.1 and above
 912          * support multi-channel.
 913          */
 914         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 915
 916         /*
 917          * Allocate state to manage the sub-channels.
 918          * We allocate an array based on the numbers of possible CPUs
 919          * (Hyper-V does not support cpu online/offline).
 920          * This Array will be sparseley populated with unique
 921          * channels - primary + sub-channels.
 922          * We will however populate all the slots to evenly distribute
 923          * the load.
 924          */
 925         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 926                                          GFP_KERNEL);
 927         if (stor_device->stor_chns == NULL)
 928                 return -ENOMEM;
 929
 930         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 931
 932         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 933         cpumask_set_cpu(device->channel->target_cpu,
 934                         &stor_device->alloced_cpus);
 935
 936         if (vstor_packet->storage_channel_properties.flags &
 937             STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 938                 process_sub_channels = true;
 939
 940         stor_device->max_transfer_bytes =
 941                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 942
 943         if (!is_fc)
 944                 goto done;
 945
 946         /*
 947          * For FC devices retrieve FC HBA data.
 948          */
 949         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 950         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 951         ret = storvsc_execute_vstor_op(device, request, true);
 952         if (ret != 0)
 953                 return ret;
 954
 955         /*
 956          * Cache the currently active port and node ww names.
 957          */
 958         cache_wwn(stor_device, vstor_packet);
 959
 960 done:
 961
 962         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 963         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 964         ret = storvsc_execute_vstor_op(device, request, true);
 965         if (ret != 0)
 966                 return ret;
 967
 968         if (process_sub_channels)
 969                 handle_multichannel_storage(device, max_chns);
 970
 971         return ret;
 972 }
 973
 974 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 975                                 struct scsi_cmnd *scmnd,
 976                                 struct Scsi_Host *host,
 977                                 u8 asc, u8 ascq)
 978 {
 979         struct storvsc_scan_work *wrk;
 980         void (*process_err_fn)(struct work_struct *work);
 981         struct hv_host_device *host_dev = shost_priv(host);
 982
 983         switch (SRB_STATUS(vm_srb->srb_status)) {
 984         case SRB_STATUS_ERROR:
 985         case SRB_STATUS_ABORTED:
 986         case SRB_STATUS_INVALID_REQUEST:
 987         case SRB_STATUS_INTERNAL_ERROR:
 988         case SRB_STATUS_TIMEOUT:
 989         case SRB_STATUS_SELECTION_TIMEOUT:
 990         case SRB_STATUS_BUS_RESET:
 991         case SRB_STATUS_DATA_OVERRUN:
 992                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
 993                         /* Check for capacity change */
 994                         if ((asc == 0x2a) && (ascq == 0x9)) {
 995                                 process_err_fn = storvsc_device_scan;
 996                                 /* Retry the I/O that triggered this. */
 997                                 set_host_byte(scmnd, DID_REQUEUE);
 998                                 goto do_work;
 999                         }
1000
1001                         /*
1002                          * Check for "Operating parameters have changed"
1003                          * due to Hyper-V changing the VHD/VHDX BlockSize
1004                          * when adding/removing a differencing disk. This
1005                          * causes discard_granularity to change, so do a
1006                          * rescan to pick up the new granularity. We don't
1007                          * want scsi_report_sense() to output a message
1008                          * that a sysadmin wouldn't know what to do with.
1009                          */
1010                         if ((asc == 0x3f) && (ascq != 0x03) &&
1011                                         (ascq != 0x0e)) {
1012                                 process_err_fn = storvsc_device_scan;
1013                                 set_host_byte(scmnd, DID_REQUEUE);
1014                                 goto do_work;
1015                         }
1016
1017                         /*
1018                          * Otherwise, let upper layer deal with the
1019                          * error when sense message is present
1020                          */
1021                         return;
1022                 }
1023
1024                 /*
1025                  * If there is an error; offline the device since all
1026                  * error recovery strategies would have already been
1027                  * deployed on the host side. However, if the command
1028                  * were a pass-through command deal with it appropriately.
1029                  */
1030                 switch (scmnd->cmnd[0]) {
1031                 case ATA_16:
1032                 case ATA_12:
1033                         set_host_byte(scmnd, DID_PASSTHROUGH);
1034                         break;
1035                 /*
1036                  * On some Hyper-V hosts TEST_UNIT_READY command can
1037                  * return SRB_STATUS_ERROR. Let the upper level code
1038                  * deal with it based on the sense information.
1039                  */
1040                 case TEST_UNIT_READY:
1041                         break;
1042                 default:
1043                         set_host_byte(scmnd, DID_ERROR);
1044                 }
1045                 return;
1046
1047         case SRB_STATUS_INVALID_LUN:
1048                 set_host_byte(scmnd, DID_NO_CONNECT);
1049                 process_err_fn = storvsc_remove_lun;
1050                 goto do_work;
1051
1052         }
1053         return;
1054
1055 do_work:
1056         /*
1057          * We need to schedule work to process this error; schedule it.
1058          */
1059         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1060         if (!wrk) {
1061                 set_host_byte(scmnd, DID_BAD_TARGET);
1062                 return;
1063         }
1064
1065         wrk->host = host;
1066         wrk->lun = vm_srb->lun;
1067         wrk->tgt_id = vm_srb->target_id;
1068         INIT_WORK(&wrk->work, process_err_fn);
1069         queue_work(host_dev->handle_error_wq, &wrk->work);
1070 }
1071
1072
1073 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1074                                        struct storvsc_device *stor_dev)
1075 {
1076         struct scsi_cmnd *scmnd = cmd_request->cmd;
1077         struct scsi_sense_hdr sense_hdr;
1078         struct vmscsi_request *vm_srb;
1079         u32 data_transfer_length;
1080         struct Scsi_Host *host;
1081         u32 payload_sz = cmd_request->payload_sz;
1082         void *payload = cmd_request->payload;
1083         bool sense_ok;
1084
1085         host = stor_dev->host;
1086
1087         vm_srb = &cmd_request->vstor_packet.vm_srb;
1088         data_transfer_length = vm_srb->data_transfer_length;
1089
1090         scmnd->result = vm_srb->scsi_status;
1091
1092         if (scmnd->result) {
1093                 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1094                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1095
1096                 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1097                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1098                                              &sense_hdr);
1099         }
1100
1101         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1102                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1103                                          sense_hdr.ascq);
1104                 /*
1105                  * The Windows driver set data_transfer_length on
1106                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1107                  * is untouched.  In these cases we set it to 0.
1108                  */
1109                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1110                         data_transfer_length = 0;
1111         }
1112
1113         /* Validate data_transfer_length (from Hyper-V) */
1114         if (data_transfer_length > cmd_request->payload->range.len)
1115                 data_transfer_length = cmd_request->payload->range.len;
1116
1117         scsi_set_resid(scmnd,
1118                 cmd_request->payload->range.len - data_transfer_length);
1119
1120         scsi_done(scmnd);
1121
1122         if (payload_sz >
1123                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1124                 kfree(payload);
1125 }
1126
1127 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1128                                   struct vstor_packet *vstor_packet,
1129                                   struct storvsc_cmd_request *request)
1130 {
1131         struct vstor_packet *stor_pkt;
1132         struct hv_device *device = stor_device->device;
1133
1134         stor_pkt = &request->vstor_packet;
1135
1136         /*
1137          * The current SCSI handling on the host side does
1138          * not correctly handle:
1139          * INQUIRY command with page code parameter set to 0x80
1140          * MODE_SENSE command with cmd[2] == 0x1c
1141          *
1142          * Setup srb and scsi status so this won't be fatal.
1143          * We do this so we can distinguish truly fatal failues
1144          * (srb status == 0x4) and off-line the device in that case.
1145          */
1146
1147         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1148            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1149                 vstor_packet->vm_srb.scsi_status = 0;
1150                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1151         }
1152
1153         /* Copy over the status...etc */
1154         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1155         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1156
1157         /*
1158          * Copy over the sense_info_length, but limit to the known max
1159          * size if Hyper-V returns a bad value.
1160          */
1161         stor_pkt->vm_srb.sense_info_length = min_t(u8, STORVSC_SENSE_BUFFER_SIZE,
1162                 vstor_packet->vm_srb.sense_info_length);
1163
1164         if (vstor_packet->vm_srb.scsi_status != 0 ||
1165             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1166
1167                 /*
1168                  * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1169                  * return errors when detecting devices using TEST_UNIT_READY,
1170                  * and logging these as errors produces unhelpful noise.
1171                  */
1172                 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1173                         STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1174
1175                 storvsc_log(device, loglevel,
1176                         "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1177                         scsi_cmd_to_rq(request->cmd)->tag,
1178                         stor_pkt->vm_srb.cdb[0],
1179                         vstor_packet->vm_srb.scsi_status,
1180                         vstor_packet->vm_srb.srb_status,
1181                         vstor_packet->status);
1182         }
1183
1184         if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1185             (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1186                 memcpy(request->cmd->sense_buffer,
1187                        vstor_packet->vm_srb.sense_data,
1188                        stor_pkt->vm_srb.sense_info_length);
1189
1190         stor_pkt->vm_srb.data_transfer_length =
1191                 vstor_packet->vm_srb.data_transfer_length;
1192
1193         storvsc_command_completion(request, stor_device);
1194
1195         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1196                 stor_device->drain_notify)
1197                 wake_up(&stor_device->waiting_to_drain);
1198 }
1199
1200 static void storvsc_on_receive(struct storvsc_device *stor_device,
1201                              struct vstor_packet *vstor_packet,
1202                              struct storvsc_cmd_request *request)
1203 {
1204         struct hv_host_device *host_dev;
1205         switch (vstor_packet->operation) {
1206         case VSTOR_OPERATION_COMPLETE_IO:
1207                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1208                 break;
1209
1210         case VSTOR_OPERATION_REMOVE_DEVICE:
1211         case VSTOR_OPERATION_ENUMERATE_BUS:
1212                 host_dev = shost_priv(stor_device->host);
1213                 queue_work(
1214                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1215                 break;
1216
1217         case VSTOR_OPERATION_FCHBA_DATA:
1218                 cache_wwn(stor_device, vstor_packet);
1219 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1220                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1221                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1222 #endif
1223                 break;
1224         default:
1225                 break;
1226         }
1227 }
1228
1229 static void storvsc_on_channel_callback(void *context)
1230 {
1231         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1232         const struct vmpacket_descriptor *desc;
1233         struct hv_device *device;
1234         struct storvsc_device *stor_device;
1235         struct Scsi_Host *shost;
1236         unsigned long time_limit = jiffies + msecs_to_jiffies(CALLBACK_TIMEOUT);
1237
1238         if (channel->primary_channel != NULL)
1239                 device = channel->primary_channel->device_obj;
1240         else
1241                 device = channel->device_obj;
1242
1243         stor_device = get_in_stor_device(device);
1244         if (!stor_device)
1245                 return;
1246
1247         shost = stor_device->host;
1248
1249         foreach_vmbus_pkt(desc, channel) {
1250                 struct vstor_packet *packet = hv_pkt_data(desc);
1251                 struct storvsc_cmd_request *request = NULL;
1252                 u32 pktlen = hv_pkt_datalen(desc);
1253                 u64 rqst_id = desc->trans_id;
1254                 u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
1255                         sizeof(enum vstor_packet_operation);
1256
1257                 if (unlikely(time_after(jiffies, time_limit))) {
1258                         hv_pkt_iter_close(channel);
1259                         return;
1260                 }
1261
1262                 if (pktlen < minlen) {
1263                         dev_err(&device->device,
1264                                 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1265                                 rqst_id, pktlen, minlen);
1266                         continue;
1267                 }
1268
1269                 if (rqst_id == VMBUS_RQST_INIT) {
1270                         request = &stor_device->init_request;
1271                 } else if (rqst_id == VMBUS_RQST_RESET) {
1272                         request = &stor_device->reset_request;
1273                 } else {
1274                         /* Hyper-V can send an unsolicited message with ID of 0 */
1275                         if (rqst_id == 0) {
1276                                 /*
1277                                  * storvsc_on_receive() looks at the vstor_packet in the message
1278                                  * from the ring buffer.
1279                                  *
1280                                  * - If the operation in the vstor_packet is COMPLETE_IO, then
1281                                  *   we call storvsc_on_io_completion(), and dereference the
1282                                  *   guest memory address.  Make sure we don't call
1283                                  *   storvsc_on_io_completion() with a guest memory address
1284                                  *   that is zero if Hyper-V were to construct and send such
1285                                  *   a bogus packet.
1286                                  *
1287                                  * - If the operation in the vstor_packet is FCHBA_DATA, then
1288                                  *   we call cache_wwn(), and access the data payload area of
1289                                  *   the packet (wwn_packet); however, there is no guarantee
1290                                  *   that the packet is big enough to contain such area.
1291                                  *   Future-proof the code by rejecting such a bogus packet.
1292                                  */
1293                                 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1294                                     packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1295                                         dev_err(&device->device, "Invalid packet with ID of 0\n");
1296                                         continue;
1297                                 }
1298                         } else {
1299                                 struct scsi_cmnd *scmnd;
1300
1301                                 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1302                                 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1303                                 if (scmnd == NULL) {
1304                                         dev_err(&device->device, "Incorrect transaction ID\n");
1305                                         continue;
1306                                 }
1307                                 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1308                                 scsi_dma_unmap(scmnd);
1309                         }
1310
1311                         storvsc_on_receive(stor_device, packet, request);
1312                         continue;
1313                 }
1314
1315                 memcpy(&request->vstor_packet, packet,
1316                        sizeof(struct vstor_packet));
1317                 complete(&request->wait_event);
1318         }
1319 }
1320
1321 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1322                                   bool is_fc)
1323 {
1324         struct vmstorage_channel_properties props;
1325         int ret;
1326
1327         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1328
1329         device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1330         device->channel->next_request_id_callback = storvsc_next_request_id;
1331
1332         ret = vmbus_open(device->channel,
1333                          ring_size,
1334                          ring_size,
1335                          (void *)&props,
1336                          sizeof(struct vmstorage_channel_properties),
1337                          storvsc_on_channel_callback, device->channel);
1338
1339         if (ret != 0)
1340                 return ret;
1341
1342         ret = storvsc_channel_init(device, is_fc);
1343
1344         return ret;
1345 }
1346
1347 static int storvsc_dev_remove(struct hv_device *device)
1348 {
1349         struct storvsc_device *stor_device;
1350
1351         stor_device = hv_get_drvdata(device);
1352
1353         stor_device->destroy = true;
1354
1355         /* Make sure flag is set before waiting */
1356         wmb();
1357
1358         /*
1359          * At this point, all outbound traffic should be disable. We
1360          * only allow inbound traffic (responses) to proceed so that
1361          * outstanding requests can be completed.
1362          */
1363
1364         storvsc_wait_to_drain(stor_device);
1365
1366         /*
1367          * Since we have already drained, we don't need to busy wait
1368          * as was done in final_release_stor_device()
1369          * Note that we cannot set the ext pointer to NULL until
1370          * we have drained - to drain the outgoing packets, we need to
1371          * allow incoming packets.
1372          */
1373         hv_set_drvdata(device, NULL);
1374
1375         /* Close the channel */
1376         vmbus_close(device->channel);
1377
1378         kfree(stor_device->stor_chns);
1379         kfree(stor_device);
1380         return 0;
1381 }
1382
1383 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1384                                         u16 q_num)
1385 {
1386         u16 slot = 0;
1387         u16 hash_qnum;
1388         const struct cpumask *node_mask;
1389         int num_channels, tgt_cpu;
1390
1391         if (stor_device->num_sc == 0) {
1392                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1393                 return stor_device->device->channel;
1394         }
1395
1396         /*
1397          * Our channel array is sparsley populated and we
1398          * initiated I/O on a processor/hw-q that does not
1399          * currently have a designated channel. Fix this.
1400          * The strategy is simple:
1401          * I. Ensure NUMA locality
1402          * II. Distribute evenly (best effort)
1403          */
1404
1405         node_mask = cpumask_of_node(cpu_to_node(q_num));
1406
1407         num_channels = 0;
1408         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1409                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1410                         num_channels++;
1411         }
1412         if (num_channels == 0) {
1413                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1414                 return stor_device->device->channel;
1415         }
1416
1417         hash_qnum = q_num;
1418         while (hash_qnum >= num_channels)
1419                 hash_qnum -= num_channels;
1420
1421         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1422                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1423                         continue;
1424                 if (slot == hash_qnum)
1425                         break;
1426                 slot++;
1427         }
1428
1429         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1430
1431         return stor_device->stor_chns[q_num];
1432 }
1433
1434
1435 static int storvsc_do_io(struct hv_device *device,
1436                          struct storvsc_cmd_request *request, u16 q_num)
1437 {
1438         struct storvsc_device *stor_device;
1439         struct vstor_packet *vstor_packet;
1440         struct vmbus_channel *outgoing_channel, *channel;
1441         unsigned long flags;
1442         int ret = 0;
1443         const struct cpumask *node_mask;
1444         int tgt_cpu;
1445
1446         vstor_packet = &request->vstor_packet;
1447         stor_device = get_out_stor_device(device);
1448
1449         if (!stor_device)
1450                 return -ENODEV;
1451
1452
1453         request->device  = device;
1454         /*
1455          * Select an appropriate channel to send the request out.
1456          */
1457         /* See storvsc_change_target_cpu(). */
1458         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1459         if (outgoing_channel != NULL) {
1460                 if (outgoing_channel->target_cpu == q_num) {
1461                         /*
1462                          * Ideally, we want to pick a different channel if
1463                          * available on the same NUMA node.
1464                          */
1465                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1466                         for_each_cpu_wrap(tgt_cpu,
1467                                  &stor_device->alloced_cpus, q_num + 1) {
1468                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1469                                         continue;
1470                                 if (tgt_cpu == q_num)
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                         /*
1485                          * All the other channels on the same NUMA node are
1486                          * busy. Try to use the channel on the current CPU
1487                          */
1488                         if (hv_get_avail_to_write_percent(
1489                                                 &outgoing_channel->outbound)
1490                                         > ring_avail_percent_lowater)
1491                                 goto found_channel;
1492
1493                         /*
1494                          * If we reach here, all the channels on the current
1495                          * NUMA node are busy. Try to find a channel in
1496                          * other NUMA nodes
1497                          */
1498                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1499                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1500                                         continue;
1501                                 channel = READ_ONCE(
1502                                         stor_device->stor_chns[tgt_cpu]);
1503                                 if (channel == NULL)
1504                                         continue;
1505                                 if (hv_get_avail_to_write_percent(
1506                                                         &channel->outbound)
1507                                                 > ring_avail_percent_lowater) {
1508                                         outgoing_channel = channel;
1509                                         goto found_channel;
1510                                 }
1511                         }
1512                 }
1513         } else {
1514                 spin_lock_irqsave(&stor_device->lock, flags);
1515                 outgoing_channel = stor_device->stor_chns[q_num];
1516                 if (outgoing_channel != NULL) {
1517                         spin_unlock_irqrestore(&stor_device->lock, flags);
1518                         goto found_channel;
1519                 }
1520                 outgoing_channel = get_og_chn(stor_device, q_num);
1521                 spin_unlock_irqrestore(&stor_device->lock, flags);
1522         }
1523
1524 found_channel:
1525         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1526
1527         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1528
1529
1530         vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1531
1532
1533         vstor_packet->vm_srb.data_transfer_length =
1534         request->payload->range.len;
1535
1536         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1537
1538         if (request->payload->range.len) {
1539
1540                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1541                                 request->payload, request->payload_sz,
1542                                 vstor_packet,
1543                                 sizeof(struct vstor_packet),
1544                                 (unsigned long)request);
1545         } else {
1546                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1547                                sizeof(struct vstor_packet),
1548                                (unsigned long)request,
1549                                VM_PKT_DATA_INBAND,
1550                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1551         }
1552
1553         if (ret != 0)
1554                 return ret;
1555
1556         atomic_inc(&stor_device->num_outstanding_req);
1557
1558         return ret;
1559 }
1560
1561 static int storvsc_device_alloc(struct scsi_device *sdevice)
1562 {
1563         /*
1564          * Set blist flag to permit the reading of the VPD pages even when
1565          * the target may claim SPC-2 compliance. MSFT targets currently
1566          * claim SPC-2 compliance while they implement post SPC-2 features.
1567          * With this flag we can correctly handle WRITE_SAME_16 issues.
1568          *
1569          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1570          * still supports REPORT LUN.
1571          */
1572         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1573
1574         return 0;
1575 }
1576
1577 static int storvsc_device_configure(struct scsi_device *sdevice)
1578 {
1579         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1580
1581         /* storvsc devices don't support MAINTENANCE_IN SCSI cmd */
1582         sdevice->no_report_opcodes = 1;
1583         sdevice->no_write_same = 1;
1584
1585         /*
1586          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1587          * if the device is a MSFT virtual device.  If the host is
1588          * WIN10 or newer, allow write_same.
1589          */
1590         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1591                 switch (vmstor_proto_version) {
1592                 case VMSTOR_PROTO_VERSION_WIN8:
1593                 case VMSTOR_PROTO_VERSION_WIN8_1:
1594                         sdevice->scsi_level = SCSI_SPC_3;
1595                         break;
1596                 }
1597
1598                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1599                         sdevice->no_write_same = 0;
1600         }
1601
1602         return 0;
1603 }
1604
1605 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1606                            sector_t capacity, int *info)
1607 {
1608         sector_t nsect = capacity;
1609         sector_t cylinders = nsect;
1610         int heads, sectors_pt;
1611
1612         /*
1613          * We are making up these values; let us keep it simple.
1614          */
1615         heads = 0xff;
1616         sectors_pt = 0x3f;      /* Sectors per track */
1617         sector_div(cylinders, heads * sectors_pt);
1618         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1619                 cylinders = 0xffff;
1620
1621         info[0] = heads;
1622         info[1] = sectors_pt;
1623         info[2] = (int)cylinders;
1624
1625         return 0;
1626 }
1627
1628 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1629 {
1630         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1631         struct hv_device *device = host_dev->dev;
1632
1633         struct storvsc_device *stor_device;
1634         struct storvsc_cmd_request *request;
1635         struct vstor_packet *vstor_packet;
1636         int ret, t;
1637
1638         stor_device = get_out_stor_device(device);
1639         if (!stor_device)
1640                 return FAILED;
1641
1642         request = &stor_device->reset_request;
1643         vstor_packet = &request->vstor_packet;
1644         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1645
1646         init_completion(&request->wait_event);
1647
1648         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1649         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1650         vstor_packet->vm_srb.path_id = stor_device->path_id;
1651
1652         ret = vmbus_sendpacket(device->channel, vstor_packet,
1653                                sizeof(struct vstor_packet),
1654                                VMBUS_RQST_RESET,
1655                                VM_PKT_DATA_INBAND,
1656                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1657         if (ret != 0)
1658                 return FAILED;
1659
1660         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1661         if (t == 0)
1662                 return TIMEOUT_ERROR;
1663
1664
1665         /*
1666          * At this point, all outstanding requests in the adapter
1667          * should have been flushed out and return to us
1668          * There is a potential race here where the host may be in
1669          * the process of responding when we return from here.
1670          * Just wait for all in-transit packets to be accounted for
1671          * before we return from here.
1672          */
1673         storvsc_wait_to_drain(stor_device);
1674
1675         return SUCCESS;
1676 }
1677
1678 /*
1679  * The host guarantees to respond to each command, although I/O latencies might
1680  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1681  * chance to perform EH.
1682  */
1683 static enum scsi_timeout_action storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1684 {
1685         return SCSI_EH_RESET_TIMER;
1686 }
1687
1688 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1689 {
1690         bool allowed = true;
1691         u8 scsi_op = scmnd->cmnd[0];
1692
1693         switch (scsi_op) {
1694         /* the host does not handle WRITE_SAME, log accident usage */
1695         case WRITE_SAME:
1696         /*
1697          * smartd sends this command and the host does not handle
1698          * this. So, don't send it.
1699          */
1700         case SET_WINDOW:
1701                 set_host_byte(scmnd, DID_ERROR);
1702                 allowed = false;
1703                 break;
1704         default:
1705                 break;
1706         }
1707         return allowed;
1708 }
1709
1710 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1711 {
1712         int ret;
1713         struct hv_host_device *host_dev = shost_priv(host);
1714         struct hv_device *dev = host_dev->dev;
1715         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1716         struct scatterlist *sgl;
1717         struct vmscsi_request *vm_srb;
1718         struct vmbus_packet_mpb_array  *payload;
1719         u32 payload_sz;
1720         u32 length;
1721
1722         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1723                 /*
1724                  * On legacy hosts filter unimplemented commands.
1725                  * Future hosts are expected to correctly handle
1726                  * unsupported commands. Furthermore, it is
1727                  * possible that some of the currently
1728                  * unsupported commands maybe supported in
1729                  * future versions of the host.
1730                  */
1731                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1732                         scsi_done(scmnd);
1733                         return 0;
1734                 }
1735         }
1736
1737         /* Setup the cmd request */
1738         cmd_request->cmd = scmnd;
1739
1740         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1741         vm_srb = &cmd_request->vstor_packet.vm_srb;
1742         vm_srb->time_out_value = 60;
1743
1744         vm_srb->srb_flags |=
1745                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1746
1747         if (scmnd->device->tagged_supported) {
1748                 vm_srb->srb_flags |=
1749                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1750                 vm_srb->queue_tag = SP_UNTAGGED;
1751                 vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
1752         }
1753
1754         /* Build the SRB */
1755         switch (scmnd->sc_data_direction) {
1756         case DMA_TO_DEVICE:
1757                 vm_srb->data_in = WRITE_TYPE;
1758                 vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
1759                 break;
1760         case DMA_FROM_DEVICE:
1761                 vm_srb->data_in = READ_TYPE;
1762                 vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
1763                 break;
1764         case DMA_NONE:
1765                 vm_srb->data_in = UNKNOWN_TYPE;
1766                 vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1767                 break;
1768         default:
1769                 /*
1770                  * This is DMA_BIDIRECTIONAL or something else we are never
1771                  * supposed to see here.
1772                  */
1773                 WARN(1, "Unexpected data direction: %d\n",
1774                      scmnd->sc_data_direction);
1775                 return -EINVAL;
1776         }
1777
1778
1779         vm_srb->port_number = host_dev->port;
1780         vm_srb->path_id = scmnd->device->channel;
1781         vm_srb->target_id = scmnd->device->id;
1782         vm_srb->lun = scmnd->device->lun;
1783
1784         vm_srb->cdb_length = scmnd->cmd_len;
1785
1786         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1787
1788         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1789
1790         length = scsi_bufflen(scmnd);
1791         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1792         payload_sz = 0;
1793
1794         if (scsi_sg_count(scmnd)) {
1795                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1796                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1797                 struct scatterlist *sg;
1798                 unsigned long hvpfn, hvpfns_to_add;
1799                 int j, i = 0, sg_count;
1800
1801                 payload_sz = (hvpg_count * sizeof(u64) +
1802                               sizeof(struct vmbus_packet_mpb_array));
1803
1804                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1805                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1806                         if (!payload)
1807                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1808                 }
1809
1810                 payload->range.len = length;
1811                 payload->range.offset = offset_in_hvpg;
1812
1813                 sg_count = scsi_dma_map(scmnd);
1814                 if (sg_count < 0) {
1815                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1816                         goto err_free_payload;
1817                 }
1818
1819                 for_each_sg(sgl, sg, sg_count, j) {
1820                         /*
1821                          * Init values for the current sgl entry. hvpfns_to_add
1822                          * is in units of Hyper-V size pages. Handling the
1823                          * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1824                          * values of sgl->offset that are larger than PAGE_SIZE.
1825                          * Such offsets are handled even on other than the first
1826                          * sgl entry, provided they are a multiple of PAGE_SIZE.
1827                          */
1828                         hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1829                         hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1830                                                  sg_dma_len(sg)) - hvpfn;
1831
1832                         /*
1833                          * Fill the next portion of the PFN array with
1834                          * sequential Hyper-V PFNs for the continguous physical
1835                          * memory described by the sgl entry. The end of the
1836                          * last sgl should be reached at the same time that
1837                          * the PFN array is filled.
1838                          */
1839                         while (hvpfns_to_add--)
1840                                 payload->range.pfn_array[i++] = hvpfn++;
1841                 }
1842         }
1843
1844         cmd_request->payload = payload;
1845         cmd_request->payload_sz = payload_sz;
1846
1847         /* Invokes the vsc to start an IO */
1848         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1849         put_cpu();
1850
1851         if (ret)
1852                 scsi_dma_unmap(scmnd);
1853
1854         if (ret == -EAGAIN) {
1855                 /* no more space */
1856                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1857                 goto err_free_payload;
1858         }
1859
1860         return 0;
1861
1862 err_free_payload:
1863         if (payload_sz > sizeof(cmd_request->mpb))
1864                 kfree(payload);
1865
1866         return ret;
1867 }
1868
1869 static struct scsi_host_template scsi_driver = {
1870         .module =               THIS_MODULE,
1871         .name =                 "storvsc_host_t",
1872         .cmd_size =             sizeof(struct storvsc_cmd_request),
1873         .bios_param =           storvsc_get_chs,
1874         .queuecommand =         storvsc_queuecommand,
1875         .eh_host_reset_handler =        storvsc_host_reset_handler,
1876         .proc_name =            "storvsc_host",
1877         .eh_timed_out =         storvsc_eh_timed_out,
1878         .slave_alloc =          storvsc_device_alloc,
1879         .slave_configure =      storvsc_device_configure,
1880         .cmd_per_lun =          2048,
1881         .this_id =              -1,
1882         /* Ensure there are no gaps in presented sgls */
1883         .virt_boundary_mask =   HV_HYP_PAGE_SIZE - 1,
1884         .no_write_same =        1,
1885         .track_queue_depth =    1,
1886         .change_queue_depth =   storvsc_change_queue_depth,
1887 };
1888
1889 enum {
1890         SCSI_GUID,
1891         IDE_GUID,
1892         SFC_GUID,
1893 };
1894
1895 static const struct hv_vmbus_device_id id_table[] = {
1896         /* SCSI guid */
1897         { HV_SCSI_GUID,
1898           .driver_data = SCSI_GUID
1899         },
1900         /* IDE guid */
1901         { HV_IDE_GUID,
1902           .driver_data = IDE_GUID
1903         },
1904         /* Fibre Channel GUID */
1905         {
1906           HV_SYNTHFC_GUID,
1907           .driver_data = SFC_GUID
1908         },
1909         { },
1910 };
1911
1912 MODULE_DEVICE_TABLE(vmbus, id_table);
1913
1914 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1915
1916 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1917 {
1918         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1919 }
1920
1921 static int storvsc_probe(struct hv_device *device,
1922                         const struct hv_vmbus_device_id *dev_id)
1923 {
1924         int ret;
1925         int num_cpus = num_online_cpus();
1926         int num_present_cpus = num_present_cpus();
1927         struct Scsi_Host *host;
1928         struct hv_host_device *host_dev;
1929         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1930         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1931         int target = 0;
1932         struct storvsc_device *stor_device;
1933         int max_sub_channels = 0;
1934         u32 max_xfer_bytes;
1935
1936         /*
1937          * We support sub-channels for storage on SCSI and FC controllers.
1938          * The number of sub-channels offerred is based on the number of
1939          * VCPUs in the guest.
1940          */
1941         if (!dev_is_ide)
1942                 max_sub_channels =
1943                         (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1944
1945         scsi_driver.can_queue = max_outstanding_req_per_channel *
1946                                 (max_sub_channels + 1) *
1947                                 (100 - ring_avail_percent_lowater) / 100;
1948
1949         host = scsi_host_alloc(&scsi_driver,
1950                                sizeof(struct hv_host_device));
1951         if (!host)
1952                 return -ENOMEM;
1953
1954         host_dev = shost_priv(host);
1955         memset(host_dev, 0, sizeof(struct hv_host_device));
1956
1957         host_dev->port = host->host_no;
1958         host_dev->dev = device;
1959         host_dev->host = host;
1960
1961
1962         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1963         if (!stor_device) {
1964                 ret = -ENOMEM;
1965                 goto err_out0;
1966         }
1967
1968         stor_device->destroy = false;
1969         init_waitqueue_head(&stor_device->waiting_to_drain);
1970         stor_device->device = device;
1971         stor_device->host = host;
1972         spin_lock_init(&stor_device->lock);
1973         hv_set_drvdata(device, stor_device);
1974         dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
1975
1976         stor_device->port_number = host->host_no;
1977         ret = storvsc_connect_to_vsp(device, aligned_ringbuffer_size, is_fc);
1978         if (ret)
1979                 goto err_out1;
1980
1981         host_dev->path = stor_device->path_id;
1982         host_dev->target = stor_device->target_id;
1983
1984         switch (dev_id->driver_data) {
1985         case SFC_GUID:
1986                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1987                 host->max_id = STORVSC_FC_MAX_TARGETS;
1988                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1989 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1990                 host->transportt = fc_transport_template;
1991 #endif
1992                 break;
1993
1994         case SCSI_GUID:
1995                 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1996                 host->max_id = STORVSC_MAX_TARGETS;
1997                 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1998                 break;
1999
2000         default:
2001                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
2002                 host->max_id = STORVSC_IDE_MAX_TARGETS;
2003                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
2004                 break;
2005         }
2006         /* max cmd length */
2007         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
2008         /*
2009          * Any reasonable Hyper-V configuration should provide
2010          * max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
2011          * protecting it from any weird value.
2012          */
2013         max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
2014         if (is_fc)
2015                 max_xfer_bytes = min(max_xfer_bytes, STORVSC_FC_MAX_XFER_SIZE);
2016
2017         /* max_hw_sectors_kb */
2018         host->max_sectors = max_xfer_bytes >> 9;
2019         /*
2020          * There are 2 requirements for Hyper-V storvsc sgl segments,
2021          * based on which the below calculation for max segments is
2022          * done:
2023          *
2024          * 1. Except for the first and last sgl segment, all sgl segments
2025          *    should be align to HV_HYP_PAGE_SIZE, that also means the
2026          *    maximum number of segments in a sgl can be calculated by
2027          *    dividing the total max transfer length by HV_HYP_PAGE_SIZE.
2028          *
2029          * 2. Except for the first and last, each entry in the SGL must
2030          *    have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2031          */
2032         host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2033         /*
2034          * For non-IDE disks, the host supports multiple channels.
2035          * Set the number of HW queues we are supporting.
2036          */
2037         if (!dev_is_ide) {
2038                 if (storvsc_max_hw_queues > num_present_cpus) {
2039                         storvsc_max_hw_queues = 0;
2040                         storvsc_log(device, STORVSC_LOGGING_WARN,
2041                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2042                 }
2043                 if (storvsc_max_hw_queues)
2044                         host->nr_hw_queues = storvsc_max_hw_queues;
2045                 else
2046                         host->nr_hw_queues = num_present_cpus;
2047         }
2048
2049         /*
2050          * Set the error handler work queue.
2051          */
2052         host_dev->handle_error_wq =
2053                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2054                                                 0,
2055                                                 host->host_no);
2056         if (!host_dev->handle_error_wq) {
2057                 ret = -ENOMEM;
2058                 goto err_out2;
2059         }
2060         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2061         /* Register the HBA and start the scsi bus scan */
2062         ret = scsi_add_host(host, &device->device);
2063         if (ret != 0)
2064                 goto err_out3;
2065
2066         if (!dev_is_ide) {
2067                 scsi_scan_host(host);
2068         } else {
2069                 target = (device->dev_instance.b[5] << 8 |
2070                          device->dev_instance.b[4]);
2071                 ret = scsi_add_device(host, 0, target, 0);
2072                 if (ret)
2073                         goto err_out4;
2074         }
2075 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2076         if (host->transportt == fc_transport_template) {
2077                 struct fc_rport_identifiers ids = {
2078                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2079                 };
2080
2081                 fc_host_node_name(host) = stor_device->node_name;
2082                 fc_host_port_name(host) = stor_device->port_name;
2083                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2084                 if (!stor_device->rport) {
2085                         ret = -ENOMEM;
2086                         goto err_out4;
2087                 }
2088         }
2089 #endif
2090         return 0;
2091
2092 err_out4:
2093         scsi_remove_host(host);
2094
2095 err_out3:
2096         destroy_workqueue(host_dev->handle_error_wq);
2097
2098 err_out2:
2099         /*
2100          * Once we have connected with the host, we would need to
2101          * invoke storvsc_dev_remove() to rollback this state and
2102          * this call also frees up the stor_device; hence the jump around
2103          * err_out1 label.
2104          */
2105         storvsc_dev_remove(device);
2106         goto err_out0;
2107
2108 err_out1:
2109         kfree(stor_device->stor_chns);
2110         kfree(stor_device);
2111
2112 err_out0:
2113         scsi_host_put(host);
2114         return ret;
2115 }
2116
2117 /* Change a scsi target's queue depth */
2118 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2119 {
2120         if (queue_depth > scsi_driver.can_queue)
2121                 queue_depth = scsi_driver.can_queue;
2122
2123         return scsi_change_queue_depth(sdev, queue_depth);
2124 }
2125
2126 static void storvsc_remove(struct hv_device *dev)
2127 {
2128         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2129         struct Scsi_Host *host = stor_device->host;
2130         struct hv_host_device *host_dev = shost_priv(host);
2131
2132 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2133         if (host->transportt == fc_transport_template) {
2134                 fc_remote_port_delete(stor_device->rport);
2135                 fc_remove_host(host);
2136         }
2137 #endif
2138         destroy_workqueue(host_dev->handle_error_wq);
2139         scsi_remove_host(host);
2140         storvsc_dev_remove(dev);
2141         scsi_host_put(host);
2142 }
2143
2144 static int storvsc_suspend(struct hv_device *hv_dev)
2145 {
2146         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2147         struct Scsi_Host *host = stor_device->host;
2148         struct hv_host_device *host_dev = shost_priv(host);
2149
2150         storvsc_wait_to_drain(stor_device);
2151
2152         drain_workqueue(host_dev->handle_error_wq);
2153
2154         vmbus_close(hv_dev->channel);
2155
2156         kfree(stor_device->stor_chns);
2157         stor_device->stor_chns = NULL;
2158
2159         cpumask_clear(&stor_device->alloced_cpus);
2160
2161         return 0;
2162 }
2163
2164 static int storvsc_resume(struct hv_device *hv_dev)
2165 {
2166         int ret;
2167
2168         ret = storvsc_connect_to_vsp(hv_dev, aligned_ringbuffer_size,
2169                                      hv_dev_is_fc(hv_dev));
2170         return ret;
2171 }
2172
2173 static struct hv_driver storvsc_drv = {
2174         .name = KBUILD_MODNAME,
2175         .id_table = id_table,
2176         .probe = storvsc_probe,
2177         .remove = storvsc_remove,
2178         .suspend = storvsc_suspend,
2179         .resume = storvsc_resume,
2180         .driver = {
2181                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2182         },
2183 };
2184
2185 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2186 static struct fc_function_template fc_transport_functions = {
2187         .show_host_node_name = 1,
2188         .show_host_port_name = 1,
2189 };
2190 #endif
2191
2192 static int __init storvsc_drv_init(void)
2193 {
2194         int ret;
2195
2196         /*
2197          * Divide the ring buffer data size (which is 1 page less
2198          * than the ring buffer size since that page is reserved for
2199          * the ring buffer indices) by the max request size (which is
2200          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2201          */
2202         aligned_ringbuffer_size = VMBUS_RING_SIZE(storvsc_ringbuffer_size);
2203         max_outstanding_req_per_channel =
2204                 ((aligned_ringbuffer_size - PAGE_SIZE) /
2205                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2206                 sizeof(struct vstor_packet) + sizeof(u64),
2207                 sizeof(u64)));
2208
2209 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2210         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2211         if (!fc_transport_template)
2212                 return -ENODEV;
2213 #endif
2214
2215         ret = vmbus_driver_register(&storvsc_drv);
2216
2217 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2218         if (ret)
2219                 fc_release_transport(fc_transport_template);
2220 #endif
2221
2222         return ret;
2223 }
2224
2225 static void __exit storvsc_drv_exit(void)
2226 {
2227         vmbus_driver_unregister(&storvsc_drv);
2228 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2229         fc_release_transport(fc_transport_template);
2230 #endif
2231 }
2232
2233 MODULE_LICENSE("GPL");
2234 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2235 module_init(storvsc_drv_init);
2236 module_exit(storvsc_drv_exit);