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1// SPDX-License-Identifier: GPL-2.0-only2/*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: 0.147 * V1 RC < 2008/1/31: 1.048 * V1 RC > 2008/1/31:  2.049 * Win7: 4.250 * Win8: 5.151 * Win8.1: 6.052 * Win10: 6.253 */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               265 66/*  Packet structure describing virtual storage requests. */67enum 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                 = 1382};83 84/*85 * WWN packet for Fibre Channel HBA86 */87 88struct 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 Bits101 */102 103#define SRB_FLAGS_QUEUE_ACTION_ENABLE		0x00000002104#define SRB_FLAGS_DISABLE_DISCONNECT		0x00000004105#define SRB_FLAGS_DISABLE_SYNCH_TRANSFER	0x00000008106#define SRB_FLAGS_BYPASS_FROZEN_QUEUE		0x00000010107#define SRB_FLAGS_DISABLE_AUTOSENSE		0x00000020108#define SRB_FLAGS_DATA_IN			0x00000040109#define SRB_FLAGS_DATA_OUT			0x00000080110#define SRB_FLAGS_NO_DATA_TRANSFER		0x00000000111#define SRB_FLAGS_UNSPECIFIED_DIRECTION	(SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)112#define SRB_FLAGS_NO_QUEUE_FREEZE		0x00000100113#define SRB_FLAGS_ADAPTER_CACHE_ENABLE		0x00000200114#define SRB_FLAGS_FREE_SENSE_BUFFER		0x00000400115 116/*117 * This flag indicates the request is part of the workflow for processing a D3.118 */119#define SRB_FLAGS_D3_PROCESSING			0x00000800120#define SRB_FLAGS_IS_ACTIVE			0x00010000121#define SRB_FLAGS_ALLOCATED_FROM_ZONE		0x00020000122#define SRB_FLAGS_SGLIST_FROM_POOL		0x00040000123#define SRB_FLAGS_BYPASS_LOCKED_QUEUE		0x00080000124#define SRB_FLAGS_NO_KEEP_AWAKE			0x00100000125#define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE	0x00200000126#define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT	0x00400000127#define SRB_FLAGS_DONT_START_NEXT_PACKET	0x00800000128#define SRB_FLAGS_PORT_DRIVER_RESERVED		0x0F000000129#define SRB_FLAGS_CLASS_DRIVER_RESERVED		0xF0000000130 131#define SP_UNTAGGED			((unsigned char) ~0)132#define SRB_SIMPLE_TAG_REQUEST		0x20133 134/*135 * Platform neutral description of a scsi request -136 * this remains the same across the write regardless of 32/64 bit137 * note: it's patterned off the SCSI_PASS_THROUGH structure138 */139#define STORVSC_MAX_CMD_LEN			0x10140 141/* Sense buffer size is the same for all versions since Windows 8 */142#define STORVSC_SENSE_BUFFER_SIZE		0x14143#define STORVSC_MAX_BUF_LEN_WITH_PADDING	0x14144 145/*146 * The storage protocol version is determined during the147 * initial exchange with the host.  It will indicate which148 * storage functionality is available in the host.149*/150static int vmstor_proto_version;151 152#define STORVSC_LOGGING_NONE	0153#define STORVSC_LOGGING_ERROR	1154#define STORVSC_LOGGING_WARN	2155 156static int logging_level = STORVSC_LOGGING_ERROR;157module_param(logging_level, int, S_IRUGO|S_IWUSR);158MODULE_PARM_DESC(logging_level,159	"Logging level, 0 - None, 1 - Error (default), 2 - Warning.");160 161static inline bool do_logging(int level)162{163	return logging_level >= level;164}165 166#define storvsc_log(dev, level, fmt, ...)			\167do {								\168	if (do_logging(level))					\169		dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);	\170} while (0)171 172struct 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 210static 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 different219 * properties of the channel.220 */221 222#define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL		0x1223 224struct 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. */236struct 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 changed242	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not243	 * definitely indicate incompatibility--but it does indicate mismatched244	 * 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		0x1252#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2253 254struct 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 the268		 * 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 this293 * packet.294 */295 296#define REQUEST_COMPLETION_FLAG	0x1297 298/* Matches Windows-end */299enum 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 bits307 * are flags, while the remaining 6 bits are an integer status code.  The308 * definitions here include only the subset of the integer status codes that309 * are tested for in this driver.310 */311#define SRB_STATUS_AUTOSENSE_VALID	0x80312#define SRB_STATUS_QUEUE_FROZEN		0x40313 314/* SRB status integer codes */315#define SRB_STATUS_SUCCESS		0x01316#define SRB_STATUS_ABORTED		0x02317#define SRB_STATUS_ERROR		0x04318#define SRB_STATUS_INVALID_REQUEST	0x06319#define SRB_STATUS_TIMEOUT		0x09320#define SRB_STATUS_SELECTION_TIMEOUT	0x0A321#define SRB_STATUS_BUS_RESET		0x0E322#define SRB_STATUS_DATA_OVERRUN		0x12323#define SRB_STATUS_INVALID_LUN		0x20324#define SRB_STATUS_INTERNAL_ERROR	0x30325 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 332static int storvsc_ringbuffer_size = (128 * 1024);333static int aligned_ringbuffer_size;334static u32 max_outstanding_req_per_channel;335static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);336 337static int storvsc_vcpus_per_sub_channel = 4;338static unsigned int storvsc_max_hw_queues;339 340module_param(storvsc_ringbuffer_size, int, S_IRUGO);341MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");342 343module_param(storvsc_max_hw_queues, uint, 0644);344MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");345 346module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);347MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");348 349static int ring_avail_percent_lowater = 10;350module_param(ring_avail_percent_lowater, int, S_IRUGO);351MODULE_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 */357static int storvsc_timeout = 180;358 359#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)360static struct scsi_transport_template *fc_transport_template;361#endif362 363static struct scsi_host_template scsi_driver;364static void storvsc_on_channel_callback(void *context);365 366#define STORVSC_MAX_LUNS_PER_TARGET			255367#define STORVSC_MAX_TARGETS				2368#define STORVSC_MAX_CHANNELS				8369 370#define STORVSC_FC_MAX_LUNS_PER_TARGET			255371#define STORVSC_FC_MAX_TARGETS				128372#define STORVSC_FC_MAX_CHANNELS				8373#define STORVSC_FC_MAX_XFER_SIZE			((u32)(512 * 1024))374 375#define STORVSC_IDE_MAX_LUNS_PER_TARGET			64376#define STORVSC_IDE_MAX_TARGETS				1377#define STORVSC_IDE_MAX_CHANNELS			1378 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 385struct 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 */402struct 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 scsi414	 * controller. In reality, the pathid, targetid is always 0415	 * and the port is set by us416	 */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#endif450};451 452struct 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 462struct storvsc_scan_work {463	struct work_struct work;464	struct Scsi_Host *host;465	u8 lun;466	u8 tgt_id;467};468 469static 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 482done:483	kfree(wrk);484}485 486static 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 the496	 * currently known devices have been hot removed. We issue a497	 * "unit ready" command against all currently known devices.498	 * This I/O will result in an error for devices that have been499	 * 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 to502	 * scan the host. Thus we are forced to discover the LUNs that503	 * 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 515static 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 532done:533	kfree(wrk);534}535 536 537/*538 * We can get incoming messages from the host that are not in response to539 * messages that we have sent out. An example of this would be messages540 * received by the guest to notify dynamic addition/removal of LUNs. To541 * deal with potential race conditions where the driver may be in the542 * midst of being unloaded when we might receive an unsolicited message543 * from the host, we have implemented a mechanism to gurantee sequential544 * consistency:545 *546 * 1) Once the device is marked as being destroyed, we will fail all547 *    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 552static 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 566static 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 574static 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 incoming586	 * 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 593get_in_err:594	return stor_device;595 596}597 598static 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_obj610				: 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 to620	 * the "old" CPU to update the alloced_cpus mask and the stor_chns621	 * 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 637old_is_alloced:638	if (old_is_alloced)639		WRITE_ONCE(stor_device->stor_chns[old], cur_chn);640	else641		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 656static 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 unsolicited668	 * message from Hyper-V.669	 */670	return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;671}672 673static 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 710static 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 as721	 * with maxcpus=1 on the kernel boot line, Hyper-V could offer722	 * sub-channels >= the number of CPUs. These sub-channels723	 * should not be created. The primary channel is already created724	 * 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 use779	 * the sub-channel(s).780	 */781}782 783static 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 803static 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 842static 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 open860	 * channel861	 */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 above912	 * 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 CPUs919	 * (Hyper-V does not support cpu online/offline).920	 * This Array will be sparseley populated with unique921	 * channels - primary + sub-channels.922	 * We will however populate all the slots to evenly distribute923	 * 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 960done: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 974static 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 BlockSize1004			 * when adding/removing a differencing disk. This1005			 * causes discard_granularity to change, so do a1006			 * rescan to pick up the new granularity. We don't1007			 * want scsi_report_sense() to output a message1008			 * 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 the1019			 * error when sense message is present1020			 */1021			return;1022		}1023 1024		/*1025		 * If there is an error; offline the device since all1026		 * error recovery strategies would have already been1027		 * deployed on the host side. However, if the command1028		 * 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 can1037		 * return SRB_STATUS_ERROR. Let the upper level code1038		 * 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 1055do_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 1073static 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 on1106		 * SRB_STATUS_DATA_OVERRUN. On other errors, this value1107		 * 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 1127static 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 does1138	 * not correctly handle:1139	 * INQUIRY command with page code parameter set to 0x801140	 * MODE_SENSE command with cmd[2] == 0x1c1141	 *1142	 * Setup srb and scsi status so this won't be fatal.1143	 * We do this so we can distinguish truly fatal failues1144	 * (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 max1159	 * 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 can1169		 * 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 1200static 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#endif1223		break;1224	default:1225		break;1226	}1227}1228 1229static 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	else1241		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 message1278				 * from the ring buffer.1279				 *1280				 * - If the operation in the vstor_packet is COMPLETE_IO, then1281				 *   we call storvsc_on_io_completion(), and dereference the1282				 *   guest memory address.  Make sure we don't call1283				 *   storvsc_on_io_completion() with a guest memory address1284				 *   that is zero if Hyper-V were to construct and send such1285				 *   a bogus packet.1286				 *1287				 * - If the operation in the vstor_packet is FCHBA_DATA, then1288				 *   we call cache_wwn(), and access the data payload area of1289				 *   the packet (wwn_packet); however, there is no guarantee1290				 *   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 1321static 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 1347static 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. We1360	 * only allow inbound traffic (responses) to proceed so that1361	 * 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 wait1368	 * as was done in final_release_stor_device()1369	 * Note that we cannot set the ext pointer to NULL until1370	 * we have drained - to drain the outgoing packets, we need to1371	 * 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 1383static 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 we1398	 * initiated I/O on a processor/hw-q that does not1399	 * currently have a designated channel. Fix this.1400	 * The strategy is simple:1401	 * I. Ensure NUMA locality1402	 * 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 1435static 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 if1463			 * 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 are1486			 * busy. Try to use the channel on the current CPU1487			 */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 current1495			 * NUMA node are busy. Try to find a channel in1496			 * other NUMA nodes1497			 */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 1524found_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 1561static int storvsc_device_alloc(struct scsi_device *sdevice)1562{1563	/*1564	 * Set blist flag to permit the reading of the VPD pages even when1565	 * the target may claim SPC-2 compliance. MSFT targets currently1566	 * 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 but1570	 * still supports REPORT LUN.1571	 */1572	sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;1573 1574	return 0;1575}1576 1577static 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-31587	 * if the device is a MSFT virtual device.  If the host is1588	 * 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 1605static 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 1628static 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 adapter1667	 * should have been flushed out and return to us1668	 * There is a potential race here where the host may be in1669	 * the process of responding when we return from here.1670	 * Just wait for all in-transit packets to be accounted for1671	 * 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 might1680 * be unbounded on Azure.  Reset the timer unconditionally to give the host a1681 * chance to perform EH.1682 */1683static enum scsi_timeout_action storvsc_eh_timed_out(struct scsi_cmnd *scmnd)1684{1685	return SCSI_EH_RESET_TIMER;1686}1687 1688static 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 handle1698	 * 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 1710static 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 handle1726		 * unsupported commands. Furthermore, it is1727		 * possible that some of the currently1728		 * unsupported commands maybe supported in1729		 * 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 never1771		 * 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_add1822			 * is in units of Hyper-V size pages. Handling the1823			 * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles1824			 * values of sgl->offset that are larger than PAGE_SIZE.1825			 * Such offsets are handled even on other than the first1826			 * 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 with1834			 * sequential Hyper-V PFNs for the continguous physical1835			 * memory described by the sgl entry. The end of the1836			 * last sgl should be reached at the same time that1837			 * 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 1862err_free_payload:1863	if (payload_sz > sizeof(cmd_request->mpb))1864		kfree(payload);1865 1866	return ret;1867}1868 1869static 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 1889enum {1890	SCSI_GUID,1891	IDE_GUID,1892	SFC_GUID,1893};1894 1895static const struct hv_vmbus_device_id id_table[] = {1896	/* SCSI guid */1897	{ HV_SCSI_GUID,1898	  .driver_data = SCSI_GUID1899	},1900	/* IDE guid */1901	{ HV_IDE_GUID,1902	  .driver_data = IDE_GUID1903	},1904	/* Fibre Channel GUID */1905	{1906	  HV_SYNTHFC_GUID,1907	  .driver_data = SFC_GUID1908	},1909	{ },1910};1911 1912MODULE_DEVICE_TABLE(vmbus, id_table);1913 1914static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };1915 1916static bool hv_dev_is_fc(struct hv_device *hv_dev)1917{1918	return guid_equal(&fc_guid.guid, &hv_dev->dev_type);1919}1920 1921static 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 of1939	 * 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#endif1992		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 provide2010	 * 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 is2022	 * done:2023	 *2024	 * 1. Except for the first and last sgl segment, all sgl segments2025	 *    should be align to HV_HYP_PAGE_SIZE, that also means the2026	 *    maximum number of segments in a sgl can be calculated by2027	 *    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 must2030	 *    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		else2046			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#endif2090	return 0;2091 2092err_out4:2093	scsi_remove_host(host);2094 2095err_out3:2096	destroy_workqueue(host_dev->handle_error_wq);2097 2098err_out2:2099	/*2100	 * Once we have connected with the host, we would need to2101	 * invoke storvsc_dev_remove() to rollback this state and2102	 * this call also frees up the stor_device; hence the jump around2103	 * err_out1 label.2104	 */2105	storvsc_dev_remove(device);2106	goto err_out0;2107 2108err_out1:2109	kfree(stor_device->stor_chns);2110	kfree(stor_device);2111 2112err_out0:2113	scsi_host_put(host);2114	return ret;2115}2116 2117/* Change a scsi target's queue depth */2118static 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 2126static 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#endif2138	destroy_workqueue(host_dev->handle_error_wq);2139	scsi_remove_host(host);2140	storvsc_dev_remove(dev);2141	scsi_host_put(host);2142}2143 2144static 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 2164static 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 2173static 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)2186static struct fc_function_template fc_transport_functions = {2187	.show_host_node_name = 1,2188	.show_host_port_name = 1,2189};2190#endif2191 2192static int __init storvsc_drv_init(void)2193{2194	int ret;2195 2196	/*2197	 * Divide the ring buffer data size (which is 1 page less2198	 * than the ring buffer size since that page is reserved for2199	 * the ring buffer indices) by the max request size (which is2200	 * 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#endif2214 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#endif2221 2222	return ret;2223}2224 2225static 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#endif2231}2232 2233MODULE_LICENSE("GPL");2234MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");2235module_init(storvsc_drv_init);2236module_exit(storvsc_drv_exit);2237