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   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. */
  63enum 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
  84struct 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 */
 149static 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*/
 156static int vmstor_proto_version;
 157
 158#define STORVSC_LOGGING_NONE	0
 159#define STORVSC_LOGGING_ERROR	1
 160#define STORVSC_LOGGING_WARN	2
 161
 162static int logging_level = STORVSC_LOGGING_ERROR;
 163module_param(logging_level, int, S_IRUGO|S_IWUSR);
 164MODULE_PARM_DESC(logging_level,
 165	"Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 166
 167static inline bool do_logging(int level)
 168{
 169	return logging_level >= level;
 170}
 171
 172#define storvsc_log(dev, level, fmt, ...)			\
 173do {								\
 174	if (do_logging(level))					\
 175		dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);	\
 176} while (0)
 177
 178struct 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
 190struct 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/*
 221 * The size of the vmscsi_request has changed in win8. The
 222 * additional size is because of new elements added to the
 223 * structure. These elements are valid only when we are talking
 224 * to a win8 host.
 225 * Track the correction to size we need to apply. This value
 226 * will likely change during protocol negotiation but it is
 227 * valid to start by assuming pre-Win8.
 228 */
 229static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 230
 231/*
 232 * The list of storage protocols in order of preference.
 233 */
 234struct vmstor_protocol {
 235	int protocol_version;
 236	int sense_buffer_size;
 237	int vmscsi_size_delta;
 238};
 239
 240
 241static const struct vmstor_protocol vmstor_protocols[] = {
 242	{
 243		VMSTOR_PROTO_VERSION_WIN10,
 244		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 245		0
 246	},
 247	{
 248		VMSTOR_PROTO_VERSION_WIN8_1,
 249		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 250		0
 251	},
 252	{
 253		VMSTOR_PROTO_VERSION_WIN8,
 254		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 255		0
 256	},
 257	{
 258		VMSTOR_PROTO_VERSION_WIN7,
 259		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 260		sizeof(struct vmscsi_win8_extension),
 261	},
 262	{
 263		VMSTOR_PROTO_VERSION_WIN6,
 264		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 265		sizeof(struct vmscsi_win8_extension),
 266	}
 267};
 268
 269
 270/*
 271 * This structure is sent during the initialization phase to get the different
 272 * properties of the channel.
 273 */
 274
 275#define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL		0x1
 276
 277struct vmstorage_channel_properties {
 278	u32 reserved;
 279	u16 max_channel_cnt;
 280	u16 reserved1;
 281
 282	u32 flags;
 283	u32   max_transfer_bytes;
 284
 285	u64  reserved2;
 286} __packed;
 287
 288/*  This structure is sent during the storage protocol negotiations. */
 289struct vmstorage_protocol_version {
 290	/* Major (MSW) and minor (LSW) version numbers. */
 291	u16 major_minor;
 292
 293	/*
 294	 * Revision number is auto-incremented whenever this file is changed
 295	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 296	 * definitely indicate incompatibility--but it does indicate mismatched
 297	 * builds.
 298	 * This is only used on the windows side. Just set it to 0.
 299	 */
 300	u16 revision;
 301} __packed;
 302
 303/* Channel Property Flags */
 304#define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
 305#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
 306
 307struct vstor_packet {
 308	/* Requested operation type */
 309	enum vstor_packet_operation operation;
 310
 311	/*  Flags - see below for values */
 312	u32 flags;
 313
 314	/* Status of the request returned from the server side. */
 315	u32 status;
 316
 317	/* Data payload area */
 318	union {
 319		/*
 320		 * Structure used to forward SCSI commands from the
 321		 * client to the server.
 322		 */
 323		struct vmscsi_request vm_srb;
 324
 325		/* Structure used to query channel properties. */
 326		struct vmstorage_channel_properties storage_channel_properties;
 327
 328		/* Used during version negotiations. */
 329		struct vmstorage_protocol_version version;
 330
 331		/* Fibre channel address packet */
 332		struct hv_fc_wwn_packet wwn_packet;
 333
 334		/* Number of sub-channels to create */
 335		u16 sub_channel_count;
 336
 337		/* This will be the maximum of the union members */
 338		u8  buffer[0x34];
 339	};
 340} __packed;
 341
 342/*
 343 * Packet Flags:
 344 *
 345 * This flag indicates that the server should send back a completion for this
 346 * packet.
 347 */
 348
 349#define REQUEST_COMPLETION_FLAG	0x1
 350
 351/* Matches Windows-end */
 352enum storvsc_request_type {
 353	WRITE_TYPE = 0,
 354	READ_TYPE,
 355	UNKNOWN_TYPE,
 356};
 357
 358/*
 359 * SRB status codes and masks; a subset of the codes used here.
 360 */
 361
 362#define SRB_STATUS_AUTOSENSE_VALID	0x80
 363#define SRB_STATUS_QUEUE_FROZEN		0x40
 364#define SRB_STATUS_INVALID_LUN	0x20
 365#define SRB_STATUS_SUCCESS	0x01
 366#define SRB_STATUS_ABORTED	0x02
 367#define SRB_STATUS_ERROR	0x04
 368#define SRB_STATUS_DATA_OVERRUN	0x12
 369
 370#define SRB_STATUS(status) \
 371	(status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 372/*
 373 * This is the end of Protocol specific defines.
 374 */
 375
 376static int storvsc_ringbuffer_size = (128 * 1024);
 377static u32 max_outstanding_req_per_channel;
 378static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 379
 380static int storvsc_vcpus_per_sub_channel = 4;
 381
 382module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 383MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 384
 385module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 386MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 387
 388static int ring_avail_percent_lowater = 10;
 389module_param(ring_avail_percent_lowater, int, S_IRUGO);
 390MODULE_PARM_DESC(ring_avail_percent_lowater,
 391		"Select a channel if available ring size > this in percent");
 392
 393/*
 394 * Timeout in seconds for all devices managed by this driver.
 395 */
 396static int storvsc_timeout = 180;
 397
 398#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 399static struct scsi_transport_template *fc_transport_template;
 400#endif
 401
 402static void storvsc_on_channel_callback(void *context);
 403
 404#define STORVSC_MAX_LUNS_PER_TARGET			255
 405#define STORVSC_MAX_TARGETS				2
 406#define STORVSC_MAX_CHANNELS				8
 407
 408#define STORVSC_FC_MAX_LUNS_PER_TARGET			255
 409#define STORVSC_FC_MAX_TARGETS				128
 410#define STORVSC_FC_MAX_CHANNELS				8
 411
 412#define STORVSC_IDE_MAX_LUNS_PER_TARGET			64
 413#define STORVSC_IDE_MAX_TARGETS				1
 414#define STORVSC_IDE_MAX_CHANNELS			1
 415
 416struct storvsc_cmd_request {
 417	struct scsi_cmnd *cmd;
 418
 419	struct hv_device *device;
 420
 421	/* Synchronize the request/response if needed */
 422	struct completion wait_event;
 423
 424	struct vmbus_channel_packet_multipage_buffer mpb;
 425	struct vmbus_packet_mpb_array *payload;
 426	u32 payload_sz;
 427
 428	struct vstor_packet vstor_packet;
 429};
 430
 431
 432/* A storvsc device is a device object that contains a vmbus channel */
 433struct storvsc_device {
 434	struct hv_device *device;
 435
 436	bool	 destroy;
 437	bool	 drain_notify;
 438	atomic_t num_outstanding_req;
 439	struct Scsi_Host *host;
 440
 441	wait_queue_head_t waiting_to_drain;
 442
 443	/*
 444	 * Each unique Port/Path/Target represents 1 channel ie scsi
 445	 * controller. In reality, the pathid, targetid is always 0
 446	 * and the port is set by us
 447	 */
 448	unsigned int port_number;
 449	unsigned char path_id;
 450	unsigned char target_id;
 451
 452	/*
 453	 * Max I/O, the device can support.
 454	 */
 455	u32   max_transfer_bytes;
 456	/*
 457	 * Number of sub-channels we will open.
 458	 */
 459	u16 num_sc;
 460	struct vmbus_channel **stor_chns;
 461	/*
 462	 * Mask of CPUs bound to subchannels.
 463	 */
 464	struct cpumask alloced_cpus;
 465	/*
 466	 * Serializes modifications of stor_chns[] from storvsc_do_io()
 467	 * and storvsc_change_target_cpu().
 468	 */
 469	spinlock_t lock;
 470	/* Used for vsc/vsp channel reset process */
 471	struct storvsc_cmd_request init_request;
 472	struct storvsc_cmd_request reset_request;
 473	/*
 474	 * Currently active port and node names for FC devices.
 475	 */
 476	u64 node_name;
 477	u64 port_name;
 478#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 479	struct fc_rport *rport;
 480#endif
 481};
 482
 483struct hv_host_device {
 484	struct hv_device *dev;
 485	unsigned int port;
 486	unsigned char path;
 487	unsigned char target;
 488	struct workqueue_struct *handle_error_wq;
 489	struct work_struct host_scan_work;
 490	struct Scsi_Host *host;
 491};
 492
 493struct storvsc_scan_work {
 494	struct work_struct work;
 495	struct Scsi_Host *host;
 496	u8 lun;
 497	u8 tgt_id;
 498};
 499
 500static void storvsc_device_scan(struct work_struct *work)
 501{
 502	struct storvsc_scan_work *wrk;
 503	struct scsi_device *sdev;
 504
 505	wrk = container_of(work, struct storvsc_scan_work, work);
 506
 507	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 508	if (!sdev)
 509		goto done;
 510	scsi_rescan_device(&sdev->sdev_gendev);
 511	scsi_device_put(sdev);
 512
 513done:
 514	kfree(wrk);
 515}
 516
 517static void storvsc_host_scan(struct work_struct *work)
 518{
 519	struct Scsi_Host *host;
 520	struct scsi_device *sdev;
 521	struct hv_host_device *host_device =
 522		container_of(work, struct hv_host_device, host_scan_work);
 523
 524	host = host_device->host;
 525	/*
 526	 * Before scanning the host, first check to see if any of the
 527	 * currrently known devices have been hot removed. We issue a
 528	 * "unit ready" command against all currently known devices.
 529	 * This I/O will result in an error for devices that have been
 530	 * removed. As part of handling the I/O error, we remove the device.
 531	 *
 532	 * When a LUN is added or removed, the host sends us a signal to
 533	 * scan the host. Thus we are forced to discover the LUNs that
 534	 * may have been removed this way.
 535	 */
 536	mutex_lock(&host->scan_mutex);
 537	shost_for_each_device(sdev, host)
 538		scsi_test_unit_ready(sdev, 1, 1, NULL);
 539	mutex_unlock(&host->scan_mutex);
 540	/*
 541	 * Now scan the host to discover LUNs that may have been added.
 542	 */
 543	scsi_scan_host(host);
 544}
 545
 546static void storvsc_remove_lun(struct work_struct *work)
 547{
 548	struct storvsc_scan_work *wrk;
 549	struct scsi_device *sdev;
 550
 551	wrk = container_of(work, struct storvsc_scan_work, work);
 552	if (!scsi_host_get(wrk->host))
 553		goto done;
 554
 555	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 556
 557	if (sdev) {
 558		scsi_remove_device(sdev);
 559		scsi_device_put(sdev);
 560	}
 561	scsi_host_put(wrk->host);
 562
 563done:
 564	kfree(wrk);
 565}
 566
 567
 568/*
 569 * We can get incoming messages from the host that are not in response to
 570 * messages that we have sent out. An example of this would be messages
 571 * received by the guest to notify dynamic addition/removal of LUNs. To
 572 * deal with potential race conditions where the driver may be in the
 573 * midst of being unloaded when we might receive an unsolicited message
 574 * from the host, we have implemented a mechanism to gurantee sequential
 575 * consistency:
 576 *
 577 * 1) Once the device is marked as being destroyed, we will fail all
 578 *    outgoing messages.
 579 * 2) We permit incoming messages when the device is being destroyed,
 580 *    only to properly account for messages already sent out.
 581 */
 582
 583static inline struct storvsc_device *get_out_stor_device(
 584					struct hv_device *device)
 585{
 586	struct storvsc_device *stor_device;
 587
 588	stor_device = hv_get_drvdata(device);
 589
 590	if (stor_device && stor_device->destroy)
 591		stor_device = NULL;
 592
 593	return stor_device;
 594}
 595
 596
 597static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 598{
 599	dev->drain_notify = true;
 600	wait_event(dev->waiting_to_drain,
 601		   atomic_read(&dev->num_outstanding_req) == 0);
 602	dev->drain_notify = false;
 603}
 604
 605static inline struct storvsc_device *get_in_stor_device(
 606					struct hv_device *device)
 607{
 608	struct storvsc_device *stor_device;
 609
 610	stor_device = hv_get_drvdata(device);
 611
 612	if (!stor_device)
 613		goto get_in_err;
 614
 615	/*
 616	 * If the device is being destroyed; allow incoming
 617	 * traffic only to cleanup outstanding requests.
 618	 */
 619
 620	if (stor_device->destroy  &&
 621		(atomic_read(&stor_device->num_outstanding_req) == 0))
 622		stor_device = NULL;
 623
 624get_in_err:
 625	return stor_device;
 626
 627}
 628
 629static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 630				      u32 new)
 631{
 632	struct storvsc_device *stor_device;
 633	struct vmbus_channel *cur_chn;
 634	bool old_is_alloced = false;
 635	struct hv_device *device;
 636	unsigned long flags;
 637	int cpu;
 638
 639	device = channel->primary_channel ?
 640			channel->primary_channel->device_obj
 641				: channel->device_obj;
 642	stor_device = get_out_stor_device(device);
 643	if (!stor_device)
 644		return;
 645
 646	/* See storvsc_do_io() -> get_og_chn(). */
 647	spin_lock_irqsave(&stor_device->lock, flags);
 648
 649	/*
 650	 * Determines if the storvsc device has other channels assigned to
 651	 * the "old" CPU to update the alloced_cpus mask and the stor_chns
 652	 * array.
 653	 */
 654	if (device->channel != channel && device->channel->target_cpu == old) {
 655		cur_chn = device->channel;
 656		old_is_alloced = true;
 657		goto old_is_alloced;
 658	}
 659	list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 660		if (cur_chn == channel)
 661			continue;
 662		if (cur_chn->target_cpu == old) {
 663			old_is_alloced = true;
 664			goto old_is_alloced;
 665		}
 666	}
 667
 668old_is_alloced:
 669	if (old_is_alloced)
 670		WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 671	else
 672		cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 673
 674	/* "Flush" the stor_chns array. */
 675	for_each_possible_cpu(cpu) {
 676		if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 677					cpu, &stor_device->alloced_cpus))
 678			WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 679	}
 680
 681	WRITE_ONCE(stor_device->stor_chns[new], channel);
 682	cpumask_set_cpu(new, &stor_device->alloced_cpus);
 683
 684	spin_unlock_irqrestore(&stor_device->lock, flags);
 685}
 686
 687static void handle_sc_creation(struct vmbus_channel *new_sc)
 688{
 689	struct hv_device *device = new_sc->primary_channel->device_obj;
 690	struct device *dev = &device->device;
 691	struct storvsc_device *stor_device;
 692	struct vmstorage_channel_properties props;
 693	int ret;
 694
 695	stor_device = get_out_stor_device(device);
 696	if (!stor_device)
 697		return;
 698
 699	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 700
 701	ret = vmbus_open(new_sc,
 702			 storvsc_ringbuffer_size,
 703			 storvsc_ringbuffer_size,
 704			 (void *)&props,
 705			 sizeof(struct vmstorage_channel_properties),
 706			 storvsc_on_channel_callback, new_sc);
 707
 708	/* In case vmbus_open() fails, we don't use the sub-channel. */
 709	if (ret != 0) {
 710		dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 711		return;
 712	}
 713
 714	new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 715
 716	/* Add the sub-channel to the array of available channels. */
 717	stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 718	cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 719}
 720
 721static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 722{
 723	struct device *dev = &device->device;
 724	struct storvsc_device *stor_device;
 725	int num_sc;
 726	struct storvsc_cmd_request *request;
 727	struct vstor_packet *vstor_packet;
 728	int ret, t;
 729
 730	/*
 731	 * If the number of CPUs is artificially restricted, such as
 732	 * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 733	 * sub-channels >= the number of CPUs. These sub-channels
 734	 * should not be created. The primary channel is already created
 735	 * and assigned to one CPU, so check against # CPUs - 1.
 736	 */
 737	num_sc = min((int)(num_online_cpus() - 1), max_chns);
 738	if (!num_sc)
 739		return;
 740
 741	stor_device = get_out_stor_device(device);
 742	if (!stor_device)
 743		return;
 744
 745	stor_device->num_sc = num_sc;
 746	request = &stor_device->init_request;
 747	vstor_packet = &request->vstor_packet;
 748
 749	/*
 750	 * Establish a handler for dealing with subchannels.
 751	 */
 752	vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 753
 754	/*
 755	 * Request the host to create sub-channels.
 756	 */
 757	memset(request, 0, sizeof(struct storvsc_cmd_request));
 758	init_completion(&request->wait_event);
 759	vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 760	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 761	vstor_packet->sub_channel_count = num_sc;
 762
 763	ret = vmbus_sendpacket(device->channel, vstor_packet,
 764			       (sizeof(struct vstor_packet) -
 765			       vmscsi_size_delta),
 766			       (unsigned long)request,
 767			       VM_PKT_DATA_INBAND,
 768			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 769
 770	if (ret != 0) {
 771		dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 772		return;
 773	}
 774
 775	t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 776	if (t == 0) {
 777		dev_err(dev, "Failed to create sub-channel: timed out\n");
 778		return;
 779	}
 780
 781	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 782	    vstor_packet->status != 0) {
 783		dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 784			vstor_packet->operation, vstor_packet->status);
 785		return;
 786	}
 787
 788	/*
 789	 * We need to do nothing here, because vmbus_process_offer()
 790	 * invokes channel->sc_creation_callback, which will open and use
 791	 * the sub-channel(s).
 792	 */
 793}
 794
 795static void cache_wwn(struct storvsc_device *stor_device,
 796		      struct vstor_packet *vstor_packet)
 797{
 798	/*
 799	 * Cache the currently active port and node ww names.
 800	 */
 801	if (vstor_packet->wwn_packet.primary_active) {
 802		stor_device->node_name =
 803			wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 804		stor_device->port_name =
 805			wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 806	} else {
 807		stor_device->node_name =
 808			wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 809		stor_device->port_name =
 810			wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 811	}
 812}
 813
 814
 815static int storvsc_execute_vstor_op(struct hv_device *device,
 816				    struct storvsc_cmd_request *request,
 817				    bool status_check)
 818{
 819	struct vstor_packet *vstor_packet;
 820	int ret, t;
 821
 822	vstor_packet = &request->vstor_packet;
 823
 824	init_completion(&request->wait_event);
 825	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 826
 827	ret = vmbus_sendpacket(device->channel, vstor_packet,
 828			       (sizeof(struct vstor_packet) -
 829			       vmscsi_size_delta),
 830			       (unsigned long)request,
 831			       VM_PKT_DATA_INBAND,
 832			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 833	if (ret != 0)
 834		return ret;
 835
 836	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 837	if (t == 0)
 838		return -ETIMEDOUT;
 839
 840	if (!status_check)
 841		return ret;
 842
 843	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 844	    vstor_packet->status != 0)
 845		return -EINVAL;
 846
 847	return ret;
 848}
 849
 850static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 851{
 852	struct storvsc_device *stor_device;
 853	struct storvsc_cmd_request *request;
 854	struct vstor_packet *vstor_packet;
 855	int ret, i;
 856	int max_chns;
 857	bool process_sub_channels = false;
 858
 859	stor_device = get_out_stor_device(device);
 860	if (!stor_device)
 861		return -ENODEV;
 862
 863	request = &stor_device->init_request;
 864	vstor_packet = &request->vstor_packet;
 865
 866	/*
 867	 * Now, initiate the vsc/vsp initialization protocol on the open
 868	 * channel
 869	 */
 870	memset(request, 0, sizeof(struct storvsc_cmd_request));
 871	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 872	ret = storvsc_execute_vstor_op(device, request, true);
 873	if (ret)
 874		return ret;
 875	/*
 876	 * Query host supported protocol version.
 877	 */
 878
 879	for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 880		/* reuse the packet for version range supported */
 881		memset(vstor_packet, 0, sizeof(struct vstor_packet));
 882		vstor_packet->operation =
 883			VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 884
 885		vstor_packet->version.major_minor =
 886			vmstor_protocols[i].protocol_version;
 887
 888		/*
 889		 * The revision number is only used in Windows; set it to 0.
 890		 */
 891		vstor_packet->version.revision = 0;
 892		ret = storvsc_execute_vstor_op(device, request, false);
 893		if (ret != 0)
 894			return ret;
 895
 896		if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 897			return -EINVAL;
 898
 899		if (vstor_packet->status == 0) {
 900			vmstor_proto_version =
 901				vmstor_protocols[i].protocol_version;
 902
 903			sense_buffer_size =
 904				vmstor_protocols[i].sense_buffer_size;
 905
 906			vmscsi_size_delta =
 907				vmstor_protocols[i].vmscsi_size_delta;
 908
 909			break;
 910		}
 911	}
 912
 913	if (vstor_packet->status != 0)
 914		return -EINVAL;
 915
 916
 917	memset(vstor_packet, 0, sizeof(struct vstor_packet));
 918	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 919	ret = storvsc_execute_vstor_op(device, request, true);
 920	if (ret != 0)
 921		return ret;
 922
 923	/*
 924	 * Check to see if multi-channel support is there.
 925	 * Hosts that implement protocol version of 5.1 and above
 926	 * support multi-channel.
 927	 */
 928	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 929
 930	/*
 931	 * Allocate state to manage the sub-channels.
 932	 * We allocate an array based on the numbers of possible CPUs
 933	 * (Hyper-V does not support cpu online/offline).
 934	 * This Array will be sparseley populated with unique
 935	 * channels - primary + sub-channels.
 936	 * We will however populate all the slots to evenly distribute
 937	 * the load.
 938	 */
 939	stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 940					 GFP_KERNEL);
 941	if (stor_device->stor_chns == NULL)
 942		return -ENOMEM;
 943
 944	device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 945
 946	stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 947	cpumask_set_cpu(device->channel->target_cpu,
 948			&stor_device->alloced_cpus);
 949
 950	if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 951		if (vstor_packet->storage_channel_properties.flags &
 952		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 953			process_sub_channels = true;
 954	}
 955	stor_device->max_transfer_bytes =
 956		vstor_packet->storage_channel_properties.max_transfer_bytes;
 957
 958	if (!is_fc)
 959		goto done;
 960
 961	/*
 962	 * For FC devices retrieve FC HBA data.
 963	 */
 964	memset(vstor_packet, 0, sizeof(struct vstor_packet));
 965	vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 966	ret = storvsc_execute_vstor_op(device, request, true);
 967	if (ret != 0)
 968		return ret;
 969
 970	/*
 971	 * Cache the currently active port and node ww names.
 972	 */
 973	cache_wwn(stor_device, vstor_packet);
 974
 975done:
 976
 977	memset(vstor_packet, 0, sizeof(struct vstor_packet));
 978	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 979	ret = storvsc_execute_vstor_op(device, request, true);
 980	if (ret != 0)
 981		return ret;
 982
 983	if (process_sub_channels)
 984		handle_multichannel_storage(device, max_chns);
 985
 986	return ret;
 987}
 988
 989static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 990				struct scsi_cmnd *scmnd,
 991				struct Scsi_Host *host,
 992				u8 asc, u8 ascq)
 993{
 994	struct storvsc_scan_work *wrk;
 995	void (*process_err_fn)(struct work_struct *work);
 996	struct hv_host_device *host_dev = shost_priv(host);
 997	bool do_work = false;
 998
 999	switch (SRB_STATUS(vm_srb->srb_status)) {
1000	case SRB_STATUS_ERROR:
1001		/*
1002		 * Let upper layer deal with error when
1003		 * sense message is present.
1004		 */
1005
1006		if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1007			break;
1008		/*
1009		 * If there is an error; offline the device since all
1010		 * error recovery strategies would have already been
1011		 * deployed on the host side. However, if the command
1012		 * were a pass-through command deal with it appropriately.
1013		 */
1014		switch (scmnd->cmnd[0]) {
1015		case ATA_16:
1016		case ATA_12:
1017			set_host_byte(scmnd, DID_PASSTHROUGH);
1018			break;
1019		/*
1020		 * On Some Windows hosts TEST_UNIT_READY command can return
1021		 * SRB_STATUS_ERROR, let the upper level code deal with it
1022		 * based on the sense information.
1023		 */
1024		case TEST_UNIT_READY:
1025			break;
1026		default:
1027			set_host_byte(scmnd, DID_ERROR);
1028		}
1029		break;
1030	case SRB_STATUS_INVALID_LUN:
1031		set_host_byte(scmnd, DID_NO_CONNECT);
1032		do_work = true;
1033		process_err_fn = storvsc_remove_lun;
1034		break;
1035	case SRB_STATUS_ABORTED:
1036		if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
1037		    (asc == 0x2a) && (ascq == 0x9)) {
1038			do_work = true;
1039			process_err_fn = storvsc_device_scan;
1040			/*
1041			 * Retry the I/O that triggered this.
1042			 */
1043			set_host_byte(scmnd, DID_REQUEUE);
1044		}
1045		break;
1046	}
1047
1048	if (!do_work)
1049		return;
1050
1051	/*
1052	 * We need to schedule work to process this error; schedule it.
1053	 */
1054	wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1055	if (!wrk) {
1056		set_host_byte(scmnd, DID_TARGET_FAILURE);
1057		return;
1058	}
1059
1060	wrk->host = host;
1061	wrk->lun = vm_srb->lun;
1062	wrk->tgt_id = vm_srb->target_id;
1063	INIT_WORK(&wrk->work, process_err_fn);
1064	queue_work(host_dev->handle_error_wq, &wrk->work);
1065}
1066
1067
1068static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1069				       struct storvsc_device *stor_dev)
1070{
1071	struct scsi_cmnd *scmnd = cmd_request->cmd;
1072	struct scsi_sense_hdr sense_hdr;
1073	struct vmscsi_request *vm_srb;
1074	u32 data_transfer_length;
1075	struct Scsi_Host *host;
1076	u32 payload_sz = cmd_request->payload_sz;
1077	void *payload = cmd_request->payload;
1078
1079	host = stor_dev->host;
1080
1081	vm_srb = &cmd_request->vstor_packet.vm_srb;
1082	data_transfer_length = vm_srb->data_transfer_length;
1083
1084	scmnd->result = vm_srb->scsi_status;
1085
1086	if (scmnd->result) {
1087		if (scsi_normalize_sense(scmnd->sense_buffer,
1088				SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1089		    !(sense_hdr.sense_key == NOT_READY &&
1090				 sense_hdr.asc == 0x03A) &&
1091		    do_logging(STORVSC_LOGGING_ERROR))
1092			scsi_print_sense_hdr(scmnd->device, "storvsc",
1093					     &sense_hdr);
1094	}
1095
1096	if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1097		storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1098					 sense_hdr.ascq);
1099		/*
1100		 * The Windows driver set data_transfer_length on
1101		 * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1102		 * is untouched.  In these cases we set it to 0.
1103		 */
1104		if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1105			data_transfer_length = 0;
1106	}
1107
1108	/* Validate data_transfer_length (from Hyper-V) */
1109	if (data_transfer_length > cmd_request->payload->range.len)
1110		data_transfer_length = cmd_request->payload->range.len;
1111
1112	scsi_set_resid(scmnd,
1113		cmd_request->payload->range.len - data_transfer_length);
1114
1115	scmnd->scsi_done(scmnd);
1116
1117	if (payload_sz >
1118		sizeof(struct vmbus_channel_packet_multipage_buffer))
1119		kfree(payload);
1120}
1121
1122static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1123				  struct vstor_packet *vstor_packet,
1124				  struct storvsc_cmd_request *request)
1125{
1126	struct vstor_packet *stor_pkt;
1127	struct hv_device *device = stor_device->device;
1128
1129	stor_pkt = &request->vstor_packet;
1130
1131	/*
1132	 * The current SCSI handling on the host side does
1133	 * not correctly handle:
1134	 * INQUIRY command with page code parameter set to 0x80
1135	 * MODE_SENSE command with cmd[2] == 0x1c
1136	 *
1137	 * Setup srb and scsi status so this won't be fatal.
1138	 * We do this so we can distinguish truly fatal failues
1139	 * (srb status == 0x4) and off-line the device in that case.
1140	 */
1141
1142	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1143	   (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1144		vstor_packet->vm_srb.scsi_status = 0;
1145		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1146	}
1147
1148
1149	/* Copy over the status...etc */
1150	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1151	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1152
1153	/* Validate sense_info_length (from Hyper-V) */
1154	if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
1155		vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1156
1157	stor_pkt->vm_srb.sense_info_length =
1158	vstor_packet->vm_srb.sense_info_length;
1159
1160	if (vstor_packet->vm_srb.scsi_status != 0 ||
1161	    vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1162		storvsc_log(device, STORVSC_LOGGING_WARN,
1163			"cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1164			stor_pkt->vm_srb.cdb[0],
1165			vstor_packet->vm_srb.scsi_status,
1166			vstor_packet->vm_srb.srb_status);
1167
1168	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1169		/* CHECK_CONDITION */
1170		if (vstor_packet->vm_srb.srb_status &
1171			SRB_STATUS_AUTOSENSE_VALID) {
1172			/* autosense data available */
1173
1174			storvsc_log(device, STORVSC_LOGGING_WARN,
1175				"stor pkt %p autosense data valid - len %d\n",
1176				request, vstor_packet->vm_srb.sense_info_length);
1177
1178			memcpy(request->cmd->sense_buffer,
1179			       vstor_packet->vm_srb.sense_data,
1180			       vstor_packet->vm_srb.sense_info_length);
1181
1182		}
1183	}
1184
1185	stor_pkt->vm_srb.data_transfer_length =
1186	vstor_packet->vm_srb.data_transfer_length;
1187
1188	storvsc_command_completion(request, stor_device);
1189
1190	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1191		stor_device->drain_notify)
1192		wake_up(&stor_device->waiting_to_drain);
1193
1194
1195}
1196
1197static void storvsc_on_receive(struct storvsc_device *stor_device,
1198			     struct vstor_packet *vstor_packet,
1199			     struct storvsc_cmd_request *request)
1200{
1201	struct hv_host_device *host_dev;
1202	switch (vstor_packet->operation) {
1203	case VSTOR_OPERATION_COMPLETE_IO:
1204		storvsc_on_io_completion(stor_device, vstor_packet, request);
1205		break;
1206
1207	case VSTOR_OPERATION_REMOVE_DEVICE:
1208	case VSTOR_OPERATION_ENUMERATE_BUS:
1209		host_dev = shost_priv(stor_device->host);
1210		queue_work(
1211			host_dev->handle_error_wq, &host_dev->host_scan_work);
1212		break;
1213
1214	case VSTOR_OPERATION_FCHBA_DATA:
1215		cache_wwn(stor_device, vstor_packet);
1216#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1217		fc_host_node_name(stor_device->host) = stor_device->node_name;
1218		fc_host_port_name(stor_device->host) = stor_device->port_name;
1219#endif
1220		break;
1221	default:
1222		break;
1223	}
1224}
1225
1226static void storvsc_on_channel_callback(void *context)
1227{
1228	struct vmbus_channel *channel = (struct vmbus_channel *)context;
1229	const struct vmpacket_descriptor *desc;
1230	struct hv_device *device;
1231	struct storvsc_device *stor_device;
1232
1233	if (channel->primary_channel != NULL)
1234		device = channel->primary_channel->device_obj;
1235	else
1236		device = channel->device_obj;
1237
1238	stor_device = get_in_stor_device(device);
1239	if (!stor_device)
1240		return;
1241
1242	foreach_vmbus_pkt(desc, channel) {
1243		void *packet = hv_pkt_data(desc);
1244		struct storvsc_cmd_request *request;
1245
1246		request = (struct storvsc_cmd_request *)
1247			((unsigned long)desc->trans_id);
1248
1249		if (request == &stor_device->init_request ||
1250		    request == &stor_device->reset_request) {
1251			memcpy(&request->vstor_packet, packet,
1252			       (sizeof(struct vstor_packet) - vmscsi_size_delta));
1253			complete(&request->wait_event);
1254		} else {
1255			storvsc_on_receive(stor_device, packet, request);
1256		}
1257	}
1258}
1259
1260static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1261				  bool is_fc)
1262{
1263	struct vmstorage_channel_properties props;
1264	int ret;
1265
1266	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1267
1268	ret = vmbus_open(device->channel,
1269			 ring_size,
1270			 ring_size,
1271			 (void *)&props,
1272			 sizeof(struct vmstorage_channel_properties),
1273			 storvsc_on_channel_callback, device->channel);
1274
1275	if (ret != 0)
1276		return ret;
1277
1278	ret = storvsc_channel_init(device, is_fc);
1279
1280	return ret;
1281}
1282
1283static int storvsc_dev_remove(struct hv_device *device)
1284{
1285	struct storvsc_device *stor_device;
1286
1287	stor_device = hv_get_drvdata(device);
1288
1289	stor_device->destroy = true;
1290
1291	/* Make sure flag is set before waiting */
1292	wmb();
1293
1294	/*
1295	 * At this point, all outbound traffic should be disable. We
1296	 * only allow inbound traffic (responses) to proceed so that
1297	 * outstanding requests can be completed.
1298	 */
1299
1300	storvsc_wait_to_drain(stor_device);
1301
1302	/*
1303	 * Since we have already drained, we don't need to busy wait
1304	 * as was done in final_release_stor_device()
1305	 * Note that we cannot set the ext pointer to NULL until
1306	 * we have drained - to drain the outgoing packets, we need to
1307	 * allow incoming packets.
1308	 */
1309	hv_set_drvdata(device, NULL);
1310
1311	/* Close the channel */
1312	vmbus_close(device->channel);
1313
1314	kfree(stor_device->stor_chns);
1315	kfree(stor_device);
1316	return 0;
1317}
1318
1319static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1320					u16 q_num)
1321{
1322	u16 slot = 0;
1323	u16 hash_qnum;
1324	const struct cpumask *node_mask;
1325	int num_channels, tgt_cpu;
1326
1327	if (stor_device->num_sc == 0) {
1328		stor_device->stor_chns[q_num] = stor_device->device->channel;
1329		return stor_device->device->channel;
1330	}
1331
1332	/*
1333	 * Our channel array is sparsley populated and we
1334	 * initiated I/O on a processor/hw-q that does not
1335	 * currently have a designated channel. Fix this.
1336	 * The strategy is simple:
1337	 * I. Ensure NUMA locality
1338	 * II. Distribute evenly (best effort)
1339	 */
1340
1341	node_mask = cpumask_of_node(cpu_to_node(q_num));
1342
1343	num_channels = 0;
1344	for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1345		if (cpumask_test_cpu(tgt_cpu, node_mask))
1346			num_channels++;
1347	}
1348	if (num_channels == 0) {
1349		stor_device->stor_chns[q_num] = stor_device->device->channel;
1350		return stor_device->device->channel;
1351	}
1352
1353	hash_qnum = q_num;
1354	while (hash_qnum >= num_channels)
1355		hash_qnum -= num_channels;
1356
1357	for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1358		if (!cpumask_test_cpu(tgt_cpu, node_mask))
1359			continue;
1360		if (slot == hash_qnum)
1361			break;
1362		slot++;
1363	}
1364
1365	stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1366
1367	return stor_device->stor_chns[q_num];
1368}
1369
1370
1371static int storvsc_do_io(struct hv_device *device,
1372			 struct storvsc_cmd_request *request, u16 q_num)
1373{
1374	struct storvsc_device *stor_device;
1375	struct vstor_packet *vstor_packet;
1376	struct vmbus_channel *outgoing_channel, *channel;
1377	unsigned long flags;
1378	int ret = 0;
1379	const struct cpumask *node_mask;
1380	int tgt_cpu;
1381
1382	vstor_packet = &request->vstor_packet;
1383	stor_device = get_out_stor_device(device);
1384
1385	if (!stor_device)
1386		return -ENODEV;
1387
1388
1389	request->device  = device;
1390	/*
1391	 * Select an appropriate channel to send the request out.
1392	 */
1393	/* See storvsc_change_target_cpu(). */
1394	outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1395	if (outgoing_channel != NULL) {
1396		if (outgoing_channel->target_cpu == q_num) {
1397			/*
1398			 * Ideally, we want to pick a different channel if
1399			 * available on the same NUMA node.
1400			 */
1401			node_mask = cpumask_of_node(cpu_to_node(q_num));
1402			for_each_cpu_wrap(tgt_cpu,
1403				 &stor_device->alloced_cpus, q_num + 1) {
1404				if (!cpumask_test_cpu(tgt_cpu, node_mask))
1405					continue;
1406				if (tgt_cpu == q_num)
1407					continue;
1408				channel = READ_ONCE(
1409					stor_device->stor_chns[tgt_cpu]);
1410				if (channel == NULL)
1411					continue;
1412				if (hv_get_avail_to_write_percent(
1413							&channel->outbound)
1414						> ring_avail_percent_lowater) {
1415					outgoing_channel = channel;
1416					goto found_channel;
1417				}
1418			}
1419
1420			/*
1421			 * All the other channels on the same NUMA node are
1422			 * busy. Try to use the channel on the current CPU
1423			 */
1424			if (hv_get_avail_to_write_percent(
1425						&outgoing_channel->outbound)
1426					> ring_avail_percent_lowater)
1427				goto found_channel;
1428
1429			/*
1430			 * If we reach here, all the channels on the current
1431			 * NUMA node are busy. Try to find a channel in
1432			 * other NUMA nodes
1433			 */
1434			for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1435				if (cpumask_test_cpu(tgt_cpu, node_mask))
1436					continue;
1437				channel = READ_ONCE(
1438					stor_device->stor_chns[tgt_cpu]);
1439				if (channel == NULL)
1440					continue;
1441				if (hv_get_avail_to_write_percent(
1442							&channel->outbound)
1443						> ring_avail_percent_lowater) {
1444					outgoing_channel = channel;
1445					goto found_channel;
1446				}
1447			}
1448		}
1449	} else {
1450		spin_lock_irqsave(&stor_device->lock, flags);
1451		outgoing_channel = stor_device->stor_chns[q_num];
1452		if (outgoing_channel != NULL) {
1453			spin_unlock_irqrestore(&stor_device->lock, flags);
1454			goto found_channel;
1455		}
1456		outgoing_channel = get_og_chn(stor_device, q_num);
1457		spin_unlock_irqrestore(&stor_device->lock, flags);
1458	}
1459
1460found_channel:
1461	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1462
1463	vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1464					vmscsi_size_delta);
1465
1466
1467	vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1468
1469
1470	vstor_packet->vm_srb.data_transfer_length =
1471	request->payload->range.len;
1472
1473	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1474
1475	if (request->payload->range.len) {
1476
1477		ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1478				request->payload, request->payload_sz,
1479				vstor_packet,
1480				(sizeof(struct vstor_packet) -
1481				vmscsi_size_delta),
1482				(unsigned long)request);
1483	} else {
1484		ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1485			       (sizeof(struct vstor_packet) -
1486				vmscsi_size_delta),
1487			       (unsigned long)request,
1488			       VM_PKT_DATA_INBAND,
1489			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1490	}
1491
1492	if (ret != 0)
1493		return ret;
1494
1495	atomic_inc(&stor_device->num_outstanding_req);
1496
1497	return ret;
1498}
1499
1500static int storvsc_device_alloc(struct scsi_device *sdevice)
1501{
1502	/*
1503	 * Set blist flag to permit the reading of the VPD pages even when
1504	 * the target may claim SPC-2 compliance. MSFT targets currently
1505	 * claim SPC-2 compliance while they implement post SPC-2 features.
1506	 * With this flag we can correctly handle WRITE_SAME_16 issues.
1507	 *
1508	 * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1509	 * still supports REPORT LUN.
1510	 */
1511	sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1512
1513	return 0;
1514}
1515
1516static int storvsc_device_configure(struct scsi_device *sdevice)
1517{
1518	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1519
1520	sdevice->no_write_same = 1;
1521
1522	/*
1523	 * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1524	 * if the device is a MSFT virtual device.  If the host is
1525	 * WIN10 or newer, allow write_same.
1526	 */
1527	if (!strncmp(sdevice->vendor, "Msft", 4)) {
1528		switch (vmstor_proto_version) {
1529		case VMSTOR_PROTO_VERSION_WIN8:
1530		case VMSTOR_PROTO_VERSION_WIN8_1:
1531			sdevice->scsi_level = SCSI_SPC_3;
1532			break;
1533		}
1534
1535		if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1536			sdevice->no_write_same = 0;
1537	}
1538
1539	return 0;
1540}
1541
1542static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1543			   sector_t capacity, int *info)
1544{
1545	sector_t nsect = capacity;
1546	sector_t cylinders = nsect;
1547	int heads, sectors_pt;
1548
1549	/*
1550	 * We are making up these values; let us keep it simple.
1551	 */
1552	heads = 0xff;
1553	sectors_pt = 0x3f;      /* Sectors per track */
1554	sector_div(cylinders, heads * sectors_pt);
1555	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1556		cylinders = 0xffff;
1557
1558	info[0] = heads;
1559	info[1] = sectors_pt;
1560	info[2] = (int)cylinders;
1561
1562	return 0;
1563}
1564
1565static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1566{
1567	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1568	struct hv_device *device = host_dev->dev;
1569
1570	struct storvsc_device *stor_device;
1571	struct storvsc_cmd_request *request;
1572	struct vstor_packet *vstor_packet;
1573	int ret, t;
1574
1575
1576	stor_device = get_out_stor_device(device);
1577	if (!stor_device)
1578		return FAILED;
1579
1580	request = &stor_device->reset_request;
1581	vstor_packet = &request->vstor_packet;
1582	memset(vstor_packet, 0, sizeof(struct vstor_packet));
1583
1584	init_completion(&request->wait_event);
1585
1586	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1587	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1588	vstor_packet->vm_srb.path_id = stor_device->path_id;
1589
1590	ret = vmbus_sendpacket(device->channel, vstor_packet,
1591			       (sizeof(struct vstor_packet) -
1592				vmscsi_size_delta),
1593			       (unsigned long)&stor_device->reset_request,
1594			       VM_PKT_DATA_INBAND,
1595			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1596	if (ret != 0)
1597		return FAILED;
1598
1599	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1600	if (t == 0)
1601		return TIMEOUT_ERROR;
1602
1603
1604	/*
1605	 * At this point, all outstanding requests in the adapter
1606	 * should have been flushed out and return to us
1607	 * There is a potential race here where the host may be in
1608	 * the process of responding when we return from here.
1609	 * Just wait for all in-transit packets to be accounted for
1610	 * before we return from here.
1611	 */
1612	storvsc_wait_to_drain(stor_device);
1613
1614	return SUCCESS;
1615}
1616
1617/*
1618 * The host guarantees to respond to each command, although I/O latencies might
1619 * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1620 * chance to perform EH.
1621 */
1622static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1623{
1624#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1625	if (scmnd->device->host->transportt == fc_transport_template)
1626		return fc_eh_timed_out(scmnd);
1627#endif
1628	return BLK_EH_RESET_TIMER;
1629}
1630
1631static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1632{
1633	bool allowed = true;
1634	u8 scsi_op = scmnd->cmnd[0];
1635
1636	switch (scsi_op) {
1637	/* the host does not handle WRITE_SAME, log accident usage */
1638	case WRITE_SAME:
1639	/*
1640	 * smartd sends this command and the host does not handle
1641	 * this. So, don't send it.
1642	 */
1643	case SET_WINDOW:
1644		scmnd->result = ILLEGAL_REQUEST << 16;
1645		allowed = false;
1646		break;
1647	default:
1648		break;
1649	}
1650	return allowed;
1651}
1652
1653static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1654{
1655	int ret;
1656	struct hv_host_device *host_dev = shost_priv(host);
1657	struct hv_device *dev = host_dev->dev;
1658	struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1659	int i;
1660	struct scatterlist *sgl;
1661	unsigned int sg_count = 0;
1662	struct vmscsi_request *vm_srb;
1663	struct scatterlist *cur_sgl;
1664	struct vmbus_packet_mpb_array  *payload;
1665	u32 payload_sz;
1666	u32 length;
1667
1668	if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1669		/*
1670		 * On legacy hosts filter unimplemented commands.
1671		 * Future hosts are expected to correctly handle
1672		 * unsupported commands. Furthermore, it is
1673		 * possible that some of the currently
1674		 * unsupported commands maybe supported in
1675		 * future versions of the host.
1676		 */
1677		if (!storvsc_scsi_cmd_ok(scmnd)) {
1678			scmnd->scsi_done(scmnd);
1679			return 0;
1680		}
1681	}
1682
1683	/* Setup the cmd request */
1684	cmd_request->cmd = scmnd;
1685
1686	memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1687	vm_srb = &cmd_request->vstor_packet.vm_srb;
1688	vm_srb->win8_extension.time_out_value = 60;
1689
1690	vm_srb->win8_extension.srb_flags |=
1691		SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1692
1693	if (scmnd->device->tagged_supported) {
1694		vm_srb->win8_extension.srb_flags |=
1695		(SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1696		vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1697		vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1698	}
1699
1700	/* Build the SRB */
1701	switch (scmnd->sc_data_direction) {
1702	case DMA_TO_DEVICE:
1703		vm_srb->data_in = WRITE_TYPE;
1704		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1705		break;
1706	case DMA_FROM_DEVICE:
1707		vm_srb->data_in = READ_TYPE;
1708		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1709		break;
1710	case DMA_NONE:
1711		vm_srb->data_in = UNKNOWN_TYPE;
1712		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1713		break;
1714	default:
1715		/*
1716		 * This is DMA_BIDIRECTIONAL or something else we are never
1717		 * supposed to see here.
1718		 */
1719		WARN(1, "Unexpected data direction: %d\n",
1720		     scmnd->sc_data_direction);
1721		return -EINVAL;
1722	}
1723
1724
1725	vm_srb->port_number = host_dev->port;
1726	vm_srb->path_id = scmnd->device->channel;
1727	vm_srb->target_id = scmnd->device->id;
1728	vm_srb->lun = scmnd->device->lun;
1729
1730	vm_srb->cdb_length = scmnd->cmd_len;
1731
1732	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1733
1734	sgl = (struct scatterlist *)scsi_sglist(scmnd);
1735	sg_count = scsi_sg_count(scmnd);
1736
1737	length = scsi_bufflen(scmnd);
1738	payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1739	payload_sz = sizeof(cmd_request->mpb);
1740
1741	if (sg_count) {
1742		if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1743
1744			payload_sz = (sg_count * sizeof(u64) +
1745				      sizeof(struct vmbus_packet_mpb_array));
1746			payload = kzalloc(payload_sz, GFP_ATOMIC);
1747			if (!payload)
1748				return SCSI_MLQUEUE_DEVICE_BUSY;
1749		}
1750
1751		payload->range.len = length;
1752		payload->range.offset = sgl[0].offset;
1753
1754		cur_sgl = sgl;
1755		for (i = 0; i < sg_count; i++) {
1756			payload->range.pfn_array[i] =
1757				page_to_pfn(sg_page((cur_sgl)));
1758			cur_sgl = sg_next(cur_sgl);
1759		}
1760	}
1761
1762	cmd_request->payload = payload;
1763	cmd_request->payload_sz = payload_sz;
1764
1765	/* Invokes the vsc to start an IO */
1766	ret = storvsc_do_io(dev, cmd_request, get_cpu());
1767	put_cpu();
1768
1769	if (ret == -EAGAIN) {
1770		if (payload_sz > sizeof(cmd_request->mpb))
1771			kfree(payload);
1772		/* no more space */
1773		return SCSI_MLQUEUE_DEVICE_BUSY;
1774	}
1775
1776	return 0;
1777}
1778
1779static struct scsi_host_template scsi_driver = {
1780	.module	=		THIS_MODULE,
1781	.name =			"storvsc_host_t",
1782	.cmd_size =             sizeof(struct storvsc_cmd_request),
1783	.bios_param =		storvsc_get_chs,
1784	.queuecommand =		storvsc_queuecommand,
1785	.eh_host_reset_handler =	storvsc_host_reset_handler,
1786	.proc_name =		"storvsc_host",
1787	.eh_timed_out =		storvsc_eh_timed_out,
1788	.slave_alloc =		storvsc_device_alloc,
1789	.slave_configure =	storvsc_device_configure,
1790	.cmd_per_lun =		2048,
1791	.this_id =		-1,
1792	/* Make sure we dont get a sg segment crosses a page boundary */
1793	.dma_boundary =		PAGE_SIZE-1,
1794	/* Ensure there are no gaps in presented sgls */
1795	.virt_boundary_mask =	PAGE_SIZE-1,
1796	.no_write_same =	1,
1797	.track_queue_depth =	1,
1798	.change_queue_depth =	storvsc_change_queue_depth,
1799};
1800
1801enum {
1802	SCSI_GUID,
1803	IDE_GUID,
1804	SFC_GUID,
1805};
1806
1807static const struct hv_vmbus_device_id id_table[] = {
1808	/* SCSI guid */
1809	{ HV_SCSI_GUID,
1810	  .driver_data = SCSI_GUID
1811	},
1812	/* IDE guid */
1813	{ HV_IDE_GUID,
1814	  .driver_data = IDE_GUID
1815	},
1816	/* Fibre Channel GUID */
1817	{
1818	  HV_SYNTHFC_GUID,
1819	  .driver_data = SFC_GUID
1820	},
1821	{ },
1822};
1823
1824MODULE_DEVICE_TABLE(vmbus, id_table);
1825
1826static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1827
1828static bool hv_dev_is_fc(struct hv_device *hv_dev)
1829{
1830	return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1831}
1832
1833static int storvsc_probe(struct hv_device *device,
1834			const struct hv_vmbus_device_id *dev_id)
1835{
1836	int ret;
1837	int num_cpus = num_online_cpus();
1838	struct Scsi_Host *host;
1839	struct hv_host_device *host_dev;
1840	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1841	bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1842	int target = 0;
1843	struct storvsc_device *stor_device;
1844	int max_luns_per_target;
1845	int max_targets;
1846	int max_channels;
1847	int max_sub_channels = 0;
1848
1849	/*
1850	 * Based on the windows host we are running on,
1851	 * set state to properly communicate with the host.
1852	 */
1853
1854	if (vmbus_proto_version < VERSION_WIN8) {
1855		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1856		max_targets = STORVSC_IDE_MAX_TARGETS;
1857		max_channels = STORVSC_IDE_MAX_CHANNELS;
1858	} else {
1859		max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1860		max_targets = STORVSC_MAX_TARGETS;
1861		max_channels = STORVSC_MAX_CHANNELS;
1862		/*
1863		 * On Windows8 and above, we support sub-channels for storage
1864		 * on SCSI and FC controllers.
1865		 * The number of sub-channels offerred is based on the number of
1866		 * VCPUs in the guest.
1867		 */
1868		if (!dev_is_ide)
1869			max_sub_channels =
1870				(num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1871	}
1872
1873	scsi_driver.can_queue = max_outstanding_req_per_channel *
1874				(max_sub_channels + 1) *
1875				(100 - ring_avail_percent_lowater) / 100;
1876
1877	host = scsi_host_alloc(&scsi_driver,
1878			       sizeof(struct hv_host_device));
1879	if (!host)
1880		return -ENOMEM;
1881
1882	host_dev = shost_priv(host);
1883	memset(host_dev, 0, sizeof(struct hv_host_device));
1884
1885	host_dev->port = host->host_no;
1886	host_dev->dev = device;
1887	host_dev->host = host;
1888
1889
1890	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1891	if (!stor_device) {
1892		ret = -ENOMEM;
1893		goto err_out0;
1894	}
1895
1896	stor_device->destroy = false;
1897	init_waitqueue_head(&stor_device->waiting_to_drain);
1898	stor_device->device = device;
1899	stor_device->host = host;
1900	spin_lock_init(&stor_device->lock);
1901	hv_set_drvdata(device, stor_device);
1902
1903	stor_device->port_number = host->host_no;
1904	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1905	if (ret)
1906		goto err_out1;
1907
1908	host_dev->path = stor_device->path_id;
1909	host_dev->target = stor_device->target_id;
1910
1911	switch (dev_id->driver_data) {
1912	case SFC_GUID:
1913		host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1914		host->max_id = STORVSC_FC_MAX_TARGETS;
1915		host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1916#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1917		host->transportt = fc_transport_template;
1918#endif
1919		break;
1920
1921	case SCSI_GUID:
1922		host->max_lun = max_luns_per_target;
1923		host->max_id = max_targets;
1924		host->max_channel = max_channels - 1;
1925		break;
1926
1927	default:
1928		host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1929		host->max_id = STORVSC_IDE_MAX_TARGETS;
1930		host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1931		break;
1932	}
1933	/* max cmd length */
1934	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1935
1936	/*
1937	 * set the table size based on the info we got
1938	 * from the host.
1939	 */
1940	host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1941	/*
1942	 * For non-IDE disks, the host supports multiple channels.
1943	 * Set the number of HW queues we are supporting.
1944	 */
1945	if (!dev_is_ide)
1946		host->nr_hw_queues = num_present_cpus();
1947
1948	/*
1949	 * Set the error handler work queue.
1950	 */
1951	host_dev->handle_error_wq =
1952			alloc_ordered_workqueue("storvsc_error_wq_%d",
1953						WQ_MEM_RECLAIM,
1954						host->host_no);
1955	if (!host_dev->handle_error_wq)
1956		goto err_out2;
1957	INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
1958	/* Register the HBA and start the scsi bus scan */
1959	ret = scsi_add_host(host, &device->device);
1960	if (ret != 0)
1961		goto err_out3;
1962
1963	if (!dev_is_ide) {
1964		scsi_scan_host(host);
1965	} else {
1966		target = (device->dev_instance.b[5] << 8 |
1967			 device->dev_instance.b[4]);
1968		ret = scsi_add_device(host, 0, target, 0);
1969		if (ret)
1970			goto err_out4;
1971	}
1972#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1973	if (host->transportt == fc_transport_template) {
1974		struct fc_rport_identifiers ids = {
1975			.roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
1976		};
1977
1978		fc_host_node_name(host) = stor_device->node_name;
1979		fc_host_port_name(host) = stor_device->port_name;
1980		stor_device->rport = fc_remote_port_add(host, 0, &ids);
1981		if (!stor_device->rport) {
1982			ret = -ENOMEM;
1983			goto err_out4;
1984		}
1985	}
1986#endif
1987	return 0;
1988
1989err_out4:
1990	scsi_remove_host(host);
1991
1992err_out3:
1993	destroy_workqueue(host_dev->handle_error_wq);
1994
1995err_out2:
1996	/*
1997	 * Once we have connected with the host, we would need to
1998	 * to invoke storvsc_dev_remove() to rollback this state and
1999	 * this call also frees up the stor_device; hence the jump around
2000	 * err_out1 label.
2001	 */
2002	storvsc_dev_remove(device);
2003	goto err_out0;
2004
2005err_out1:
2006	kfree(stor_device->stor_chns);
2007	kfree(stor_device);
2008
2009err_out0:
2010	scsi_host_put(host);
2011	return ret;
2012}
2013
2014/* Change a scsi target's queue depth */
2015static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2016{
2017	if (queue_depth > scsi_driver.can_queue)
2018		queue_depth = scsi_driver.can_queue;
2019
2020	return scsi_change_queue_depth(sdev, queue_depth);
2021}
2022
2023static int storvsc_remove(struct hv_device *dev)
2024{
2025	struct storvsc_device *stor_device = hv_get_drvdata(dev);
2026	struct Scsi_Host *host = stor_device->host;
2027	struct hv_host_device *host_dev = shost_priv(host);
2028
2029#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2030	if (host->transportt == fc_transport_template) {
2031		fc_remote_port_delete(stor_device->rport);
2032		fc_remove_host(host);
2033	}
2034#endif
2035	destroy_workqueue(host_dev->handle_error_wq);
2036	scsi_remove_host(host);
2037	storvsc_dev_remove(dev);
2038	scsi_host_put(host);
2039
2040	return 0;
2041}
2042
2043static int storvsc_suspend(struct hv_device *hv_dev)
2044{
2045	struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2046	struct Scsi_Host *host = stor_device->host;
2047	struct hv_host_device *host_dev = shost_priv(host);
2048
2049	storvsc_wait_to_drain(stor_device);
2050
2051	drain_workqueue(host_dev->handle_error_wq);
2052
2053	vmbus_close(hv_dev->channel);
2054
2055	kfree(stor_device->stor_chns);
2056	stor_device->stor_chns = NULL;
2057
2058	cpumask_clear(&stor_device->alloced_cpus);
2059
2060	return 0;
2061}
2062
2063static int storvsc_resume(struct hv_device *hv_dev)
2064{
2065	int ret;
2066
2067	ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2068				     hv_dev_is_fc(hv_dev));
2069	return ret;
2070}
2071
2072static struct hv_driver storvsc_drv = {
2073	.name = KBUILD_MODNAME,
2074	.id_table = id_table,
2075	.probe = storvsc_probe,
2076	.remove = storvsc_remove,
2077	.suspend = storvsc_suspend,
2078	.resume = storvsc_resume,
2079	.driver = {
2080		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
2081	},
2082};
2083
2084#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2085static struct fc_function_template fc_transport_functions = {
2086	.show_host_node_name = 1,
2087	.show_host_port_name = 1,
2088};
2089#endif
2090
2091static int __init storvsc_drv_init(void)
2092{
2093	int ret;
2094
2095	/*
2096	 * Divide the ring buffer data size (which is 1 page less
2097	 * than the ring buffer size since that page is reserved for
2098	 * the ring buffer indices) by the max request size (which is
2099	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2100	 */
2101	max_outstanding_req_per_channel =
2102		((storvsc_ringbuffer_size - PAGE_SIZE) /
2103		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2104		sizeof(struct vstor_packet) + sizeof(u64) -
2105		vmscsi_size_delta,
2106		sizeof(u64)));
2107
2108#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2109	fc_transport_template = fc_attach_transport(&fc_transport_functions);
2110	if (!fc_transport_template)
2111		return -ENODEV;
2112#endif
2113
2114	ret = vmbus_driver_register(&storvsc_drv);
2115
2116#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2117	if (ret)
2118		fc_release_transport(fc_transport_template);
2119#endif
2120
2121	return ret;
2122}
2123
2124static void __exit storvsc_drv_exit(void)
2125{
2126	vmbus_driver_unregister(&storvsc_drv);
2127#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2128	fc_release_transport(fc_transport_template);
2129#endif
2130}
2131
2132MODULE_LICENSE("GPL");
2133MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2134module_init(storvsc_drv_init);
2135module_exit(storvsc_drv_exit);