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. In the 8-bit field, the two high order bits
360 * are flags, while the remaining 6 bits are an integer status code.  The
361 * definitions here include only the subset of the integer status codes that
362 * are tested for in this driver.
363 */
364#define SRB_STATUS_AUTOSENSE_VALID	0x80
365#define SRB_STATUS_QUEUE_FROZEN		0x40
366
367/* SRB status integer codes */
368#define SRB_STATUS_SUCCESS		0x01
369#define SRB_STATUS_ABORTED		0x02
370#define SRB_STATUS_ERROR		0x04
371#define SRB_STATUS_INVALID_REQUEST	0x06
372#define SRB_STATUS_DATA_OVERRUN		0x12
373#define SRB_STATUS_INVALID_LUN		0x20
374
375#define SRB_STATUS(status) \
376	(status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
377/*
378 * This is the end of Protocol specific defines.
379 */
380
381static int storvsc_ringbuffer_size = (128 * 1024);
382static u32 max_outstanding_req_per_channel;
383static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
384
385static int storvsc_vcpus_per_sub_channel = 4;
386
387module_param(storvsc_ringbuffer_size, int, S_IRUGO);
388MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
389
390module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
391MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
392
393static int ring_avail_percent_lowater = 10;
394module_param(ring_avail_percent_lowater, int, S_IRUGO);
395MODULE_PARM_DESC(ring_avail_percent_lowater,
396		"Select a channel if available ring size > this in percent");
397
398/*
399 * Timeout in seconds for all devices managed by this driver.
400 */
401static int storvsc_timeout = 180;
402
403#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
404static struct scsi_transport_template *fc_transport_template;
405#endif
406
407static void storvsc_on_channel_callback(void *context);
408
409#define STORVSC_MAX_LUNS_PER_TARGET			255
410#define STORVSC_MAX_TARGETS				2
411#define STORVSC_MAX_CHANNELS				8
412
413#define STORVSC_FC_MAX_LUNS_PER_TARGET			255
414#define STORVSC_FC_MAX_TARGETS				128
415#define STORVSC_FC_MAX_CHANNELS				8
416
417#define STORVSC_IDE_MAX_LUNS_PER_TARGET			64
418#define STORVSC_IDE_MAX_TARGETS				1
419#define STORVSC_IDE_MAX_CHANNELS			1
420
421struct storvsc_cmd_request {
422	struct scsi_cmnd *cmd;
423
424	struct hv_device *device;
425
426	/* Synchronize the request/response if needed */
427	struct completion wait_event;
428
429	struct vmbus_channel_packet_multipage_buffer mpb;
430	struct vmbus_packet_mpb_array *payload;
431	u32 payload_sz;
432
433	struct vstor_packet vstor_packet;
434};
435
436
437/* A storvsc device is a device object that contains a vmbus channel */
438struct storvsc_device {
439	struct hv_device *device;
440
441	bool	 destroy;
442	bool	 drain_notify;
443	atomic_t num_outstanding_req;
444	struct Scsi_Host *host;
445
446	wait_queue_head_t waiting_to_drain;
447
448	/*
449	 * Each unique Port/Path/Target represents 1 channel ie scsi
450	 * controller. In reality, the pathid, targetid is always 0
451	 * and the port is set by us
452	 */
453	unsigned int port_number;
454	unsigned char path_id;
455	unsigned char target_id;
456
457	/*
458	 * Max I/O, the device can support.
459	 */
460	u32   max_transfer_bytes;
461	/*
462	 * Number of sub-channels we will open.
463	 */
464	u16 num_sc;
465	struct vmbus_channel **stor_chns;
466	/*
467	 * Mask of CPUs bound to subchannels.
468	 */
469	struct cpumask alloced_cpus;
470	/*
471	 * Serializes modifications of stor_chns[] from storvsc_do_io()
472	 * and storvsc_change_target_cpu().
473	 */
474	spinlock_t lock;
475	/* Used for vsc/vsp channel reset process */
476	struct storvsc_cmd_request init_request;
477	struct storvsc_cmd_request reset_request;
478	/*
479	 * Currently active port and node names for FC devices.
480	 */
481	u64 node_name;
482	u64 port_name;
483#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
484	struct fc_rport *rport;
485#endif
486};
487
488struct hv_host_device {
489	struct hv_device *dev;
490	unsigned int port;
491	unsigned char path;
492	unsigned char target;
493	struct workqueue_struct *handle_error_wq;
494	struct work_struct host_scan_work;
495	struct Scsi_Host *host;
496};
497
498struct storvsc_scan_work {
499	struct work_struct work;
500	struct Scsi_Host *host;
501	u8 lun;
502	u8 tgt_id;
503};
504
505static void storvsc_device_scan(struct work_struct *work)
506{
507	struct storvsc_scan_work *wrk;
508	struct scsi_device *sdev;
509
510	wrk = container_of(work, struct storvsc_scan_work, work);
511
512	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
513	if (!sdev)
514		goto done;
515	scsi_rescan_device(&sdev->sdev_gendev);
516	scsi_device_put(sdev);
517
518done:
519	kfree(wrk);
520}
521
522static void storvsc_host_scan(struct work_struct *work)
523{
524	struct Scsi_Host *host;
525	struct scsi_device *sdev;
526	struct hv_host_device *host_device =
527		container_of(work, struct hv_host_device, host_scan_work);
528
529	host = host_device->host;
530	/*
531	 * Before scanning the host, first check to see if any of the
532	 * currrently known devices have been hot removed. We issue a
533	 * "unit ready" command against all currently known devices.
534	 * This I/O will result in an error for devices that have been
535	 * removed. As part of handling the I/O error, we remove the device.
536	 *
537	 * When a LUN is added or removed, the host sends us a signal to
538	 * scan the host. Thus we are forced to discover the LUNs that
539	 * may have been removed this way.
540	 */
541	mutex_lock(&host->scan_mutex);
542	shost_for_each_device(sdev, host)
543		scsi_test_unit_ready(sdev, 1, 1, NULL);
544	mutex_unlock(&host->scan_mutex);
545	/*
546	 * Now scan the host to discover LUNs that may have been added.
547	 */
548	scsi_scan_host(host);
549}
550
551static void storvsc_remove_lun(struct work_struct *work)
552{
553	struct storvsc_scan_work *wrk;
554	struct scsi_device *sdev;
555
556	wrk = container_of(work, struct storvsc_scan_work, work);
557	if (!scsi_host_get(wrk->host))
558		goto done;
559
560	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
561
562	if (sdev) {
563		scsi_remove_device(sdev);
564		scsi_device_put(sdev);
565	}
566	scsi_host_put(wrk->host);
567
568done:
569	kfree(wrk);
570}
571
572
573/*
574 * We can get incoming messages from the host that are not in response to
575 * messages that we have sent out. An example of this would be messages
576 * received by the guest to notify dynamic addition/removal of LUNs. To
577 * deal with potential race conditions where the driver may be in the
578 * midst of being unloaded when we might receive an unsolicited message
579 * from the host, we have implemented a mechanism to gurantee sequential
580 * consistency:
581 *
582 * 1) Once the device is marked as being destroyed, we will fail all
583 *    outgoing messages.
584 * 2) We permit incoming messages when the device is being destroyed,
585 *    only to properly account for messages already sent out.
586 */
587
588static inline struct storvsc_device *get_out_stor_device(
589					struct hv_device *device)
590{
591	struct storvsc_device *stor_device;
592
593	stor_device = hv_get_drvdata(device);
594
595	if (stor_device && stor_device->destroy)
596		stor_device = NULL;
597
598	return stor_device;
599}
600
601
602static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
603{
604	dev->drain_notify = true;
605	wait_event(dev->waiting_to_drain,
606		   atomic_read(&dev->num_outstanding_req) == 0);
607	dev->drain_notify = false;
608}
609
610static inline struct storvsc_device *get_in_stor_device(
611					struct hv_device *device)
612{
613	struct storvsc_device *stor_device;
614
615	stor_device = hv_get_drvdata(device);
616
617	if (!stor_device)
618		goto get_in_err;
619
620	/*
621	 * If the device is being destroyed; allow incoming
622	 * traffic only to cleanup outstanding requests.
623	 */
624
625	if (stor_device->destroy  &&
626		(atomic_read(&stor_device->num_outstanding_req) == 0))
627		stor_device = NULL;
628
629get_in_err:
630	return stor_device;
631
632}
633
634static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
635				      u32 new)
636{
637	struct storvsc_device *stor_device;
638	struct vmbus_channel *cur_chn;
639	bool old_is_alloced = false;
640	struct hv_device *device;
641	unsigned long flags;
642	int cpu;
643
644	device = channel->primary_channel ?
645			channel->primary_channel->device_obj
646				: channel->device_obj;
647	stor_device = get_out_stor_device(device);
648	if (!stor_device)
649		return;
650
651	/* See storvsc_do_io() -> get_og_chn(). */
652	spin_lock_irqsave(&stor_device->lock, flags);
653
654	/*
655	 * Determines if the storvsc device has other channels assigned to
656	 * the "old" CPU to update the alloced_cpus mask and the stor_chns
657	 * array.
658	 */
659	if (device->channel != channel && device->channel->target_cpu == old) {
660		cur_chn = device->channel;
661		old_is_alloced = true;
662		goto old_is_alloced;
663	}
664	list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
665		if (cur_chn == channel)
666			continue;
667		if (cur_chn->target_cpu == old) {
668			old_is_alloced = true;
669			goto old_is_alloced;
670		}
671	}
672
673old_is_alloced:
674	if (old_is_alloced)
675		WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
676	else
677		cpumask_clear_cpu(old, &stor_device->alloced_cpus);
678
679	/* "Flush" the stor_chns array. */
680	for_each_possible_cpu(cpu) {
681		if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
682					cpu, &stor_device->alloced_cpus))
683			WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
684	}
685
686	WRITE_ONCE(stor_device->stor_chns[new], channel);
687	cpumask_set_cpu(new, &stor_device->alloced_cpus);
688
689	spin_unlock_irqrestore(&stor_device->lock, flags);
690}
691
692static void handle_sc_creation(struct vmbus_channel *new_sc)
693{
694	struct hv_device *device = new_sc->primary_channel->device_obj;
695	struct device *dev = &device->device;
696	struct storvsc_device *stor_device;
697	struct vmstorage_channel_properties props;
698	int ret;
699
700	stor_device = get_out_stor_device(device);
701	if (!stor_device)
702		return;
703
704	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
705
706	ret = vmbus_open(new_sc,
707			 storvsc_ringbuffer_size,
708			 storvsc_ringbuffer_size,
709			 (void *)&props,
710			 sizeof(struct vmstorage_channel_properties),
711			 storvsc_on_channel_callback, new_sc);
712
713	/* In case vmbus_open() fails, we don't use the sub-channel. */
714	if (ret != 0) {
715		dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
716		return;
717	}
718
719	new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
720
721	/* Add the sub-channel to the array of available channels. */
722	stor_device->stor_chns[new_sc->target_cpu] = new_sc;
723	cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
724}
725
726static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
727{
728	struct device *dev = &device->device;
729	struct storvsc_device *stor_device;
730	int num_sc;
731	struct storvsc_cmd_request *request;
732	struct vstor_packet *vstor_packet;
733	int ret, t;
734
735	/*
736	 * If the number of CPUs is artificially restricted, such as
737	 * with maxcpus=1 on the kernel boot line, Hyper-V could offer
738	 * sub-channels >= the number of CPUs. These sub-channels
739	 * should not be created. The primary channel is already created
740	 * and assigned to one CPU, so check against # CPUs - 1.
741	 */
742	num_sc = min((int)(num_online_cpus() - 1), max_chns);
743	if (!num_sc)
744		return;
745
746	stor_device = get_out_stor_device(device);
747	if (!stor_device)
748		return;
749
750	stor_device->num_sc = num_sc;
751	request = &stor_device->init_request;
752	vstor_packet = &request->vstor_packet;
753
754	/*
755	 * Establish a handler for dealing with subchannels.
756	 */
757	vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
758
759	/*
760	 * Request the host to create sub-channels.
761	 */
762	memset(request, 0, sizeof(struct storvsc_cmd_request));
763	init_completion(&request->wait_event);
764	vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
765	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
766	vstor_packet->sub_channel_count = num_sc;
767
768	ret = vmbus_sendpacket(device->channel, vstor_packet,
769			       (sizeof(struct vstor_packet) -
770			       vmscsi_size_delta),
771			       (unsigned long)request,
772			       VM_PKT_DATA_INBAND,
773			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
774
775	if (ret != 0) {
776		dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
777		return;
778	}
779
780	t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
781	if (t == 0) {
782		dev_err(dev, "Failed to create sub-channel: timed out\n");
783		return;
784	}
785
786	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
787	    vstor_packet->status != 0) {
788		dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
789			vstor_packet->operation, vstor_packet->status);
790		return;
791	}
792
793	/*
794	 * We need to do nothing here, because vmbus_process_offer()
795	 * invokes channel->sc_creation_callback, which will open and use
796	 * the sub-channel(s).
797	 */
798}
799
800static void cache_wwn(struct storvsc_device *stor_device,
801		      struct vstor_packet *vstor_packet)
802{
803	/*
804	 * Cache the currently active port and node ww names.
805	 */
806	if (vstor_packet->wwn_packet.primary_active) {
807		stor_device->node_name =
808			wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
809		stor_device->port_name =
810			wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
811	} else {
812		stor_device->node_name =
813			wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
814		stor_device->port_name =
815			wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
816	}
817}
818
819
820static int storvsc_execute_vstor_op(struct hv_device *device,
821				    struct storvsc_cmd_request *request,
822				    bool status_check)
823{
824	struct vstor_packet *vstor_packet;
825	int ret, t;
826
827	vstor_packet = &request->vstor_packet;
828
829	init_completion(&request->wait_event);
830	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
831
832	ret = vmbus_sendpacket(device->channel, vstor_packet,
833			       (sizeof(struct vstor_packet) -
834			       vmscsi_size_delta),
835			       (unsigned long)request,
836			       VM_PKT_DATA_INBAND,
837			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
838	if (ret != 0)
839		return ret;
840
841	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
842	if (t == 0)
843		return -ETIMEDOUT;
844
845	if (!status_check)
846		return ret;
847
848	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
849	    vstor_packet->status != 0)
850		return -EINVAL;
851
852	return ret;
853}
854
855static int storvsc_channel_init(struct hv_device *device, bool is_fc)
856{
857	struct storvsc_device *stor_device;
858	struct storvsc_cmd_request *request;
859	struct vstor_packet *vstor_packet;
860	int ret, i;
861	int max_chns;
862	bool process_sub_channels = false;
863
864	stor_device = get_out_stor_device(device);
865	if (!stor_device)
866		return -ENODEV;
867
868	request = &stor_device->init_request;
869	vstor_packet = &request->vstor_packet;
870
871	/*
872	 * Now, initiate the vsc/vsp initialization protocol on the open
873	 * channel
874	 */
875	memset(request, 0, sizeof(struct storvsc_cmd_request));
876	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
877	ret = storvsc_execute_vstor_op(device, request, true);
878	if (ret)
879		return ret;
880	/*
881	 * Query host supported protocol version.
882	 */
883
884	for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
885		/* reuse the packet for version range supported */
886		memset(vstor_packet, 0, sizeof(struct vstor_packet));
887		vstor_packet->operation =
888			VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
889
890		vstor_packet->version.major_minor =
891			vmstor_protocols[i].protocol_version;
892
893		/*
894		 * The revision number is only used in Windows; set it to 0.
895		 */
896		vstor_packet->version.revision = 0;
897		ret = storvsc_execute_vstor_op(device, request, false);
898		if (ret != 0)
899			return ret;
900
901		if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
902			return -EINVAL;
903
904		if (vstor_packet->status == 0) {
905			vmstor_proto_version =
906				vmstor_protocols[i].protocol_version;
907
908			sense_buffer_size =
909				vmstor_protocols[i].sense_buffer_size;
910
911			vmscsi_size_delta =
912				vmstor_protocols[i].vmscsi_size_delta;
913
914			break;
915		}
916	}
917
918	if (vstor_packet->status != 0)
919		return -EINVAL;
920
921
922	memset(vstor_packet, 0, sizeof(struct vstor_packet));
923	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
924	ret = storvsc_execute_vstor_op(device, request, true);
925	if (ret != 0)
926		return ret;
927
928	/*
929	 * Check to see if multi-channel support is there.
930	 * Hosts that implement protocol version of 5.1 and above
931	 * support multi-channel.
932	 */
933	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
934
935	/*
936	 * Allocate state to manage the sub-channels.
937	 * We allocate an array based on the numbers of possible CPUs
938	 * (Hyper-V does not support cpu online/offline).
939	 * This Array will be sparseley populated with unique
940	 * channels - primary + sub-channels.
941	 * We will however populate all the slots to evenly distribute
942	 * the load.
943	 */
944	stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
945					 GFP_KERNEL);
946	if (stor_device->stor_chns == NULL)
947		return -ENOMEM;
948
949	device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
950
951	stor_device->stor_chns[device->channel->target_cpu] = device->channel;
952	cpumask_set_cpu(device->channel->target_cpu,
953			&stor_device->alloced_cpus);
954
955	if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
956		if (vstor_packet->storage_channel_properties.flags &
957		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
958			process_sub_channels = true;
959	}
960	stor_device->max_transfer_bytes =
961		vstor_packet->storage_channel_properties.max_transfer_bytes;
962
963	if (!is_fc)
964		goto done;
965
966	/*
967	 * For FC devices retrieve FC HBA data.
968	 */
969	memset(vstor_packet, 0, sizeof(struct vstor_packet));
970	vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
971	ret = storvsc_execute_vstor_op(device, request, true);
972	if (ret != 0)
973		return ret;
974
975	/*
976	 * Cache the currently active port and node ww names.
977	 */
978	cache_wwn(stor_device, vstor_packet);
979
980done:
981
982	memset(vstor_packet, 0, sizeof(struct vstor_packet));
983	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
984	ret = storvsc_execute_vstor_op(device, request, true);
985	if (ret != 0)
986		return ret;
987
988	if (process_sub_channels)
989		handle_multichannel_storage(device, max_chns);
990
991	return ret;
992}
993
994static void storvsc_handle_error(struct vmscsi_request *vm_srb,
995				struct scsi_cmnd *scmnd,
996				struct Scsi_Host *host,
997				u8 asc, u8 ascq)
998{
999	struct storvsc_scan_work *wrk;
1000	void (*process_err_fn)(struct work_struct *work);
1001	struct hv_host_device *host_dev = shost_priv(host);
1002
1003	switch (SRB_STATUS(vm_srb->srb_status)) {
1004	case SRB_STATUS_ERROR:
1005	case SRB_STATUS_ABORTED:
1006	case SRB_STATUS_INVALID_REQUEST:
1007		if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
1008			/* Check for capacity change */
1009			if ((asc == 0x2a) && (ascq == 0x9)) {
1010				process_err_fn = storvsc_device_scan;
1011				/* Retry the I/O that triggered this. */
1012				set_host_byte(scmnd, DID_REQUEUE);
1013				goto do_work;
1014			}
1015
1016			/*
1017			 * Check for "Operating parameters have changed"
1018			 * due to Hyper-V changing the VHD/VHDX BlockSize
1019			 * when adding/removing a differencing disk. This
1020			 * causes discard_granularity to change, so do a
1021			 * rescan to pick up the new granularity. We don't
1022			 * want scsi_report_sense() to output a message
1023			 * that a sysadmin wouldn't know what to do with.
1024			 */
1025			if ((asc == 0x3f) && (ascq != 0x03) &&
1026					(ascq != 0x0e)) {
1027				process_err_fn = storvsc_device_scan;
1028				set_host_byte(scmnd, DID_REQUEUE);
1029				goto do_work;
1030			}
1031
1032			/*
1033			 * Otherwise, let upper layer deal with the
1034			 * error when sense message is present
1035			 */
1036			return;
1037		}
1038
1039		/*
1040		 * If there is an error; offline the device since all
1041		 * error recovery strategies would have already been
1042		 * deployed on the host side. However, if the command
1043		 * were a pass-through command deal with it appropriately.
1044		 */
1045		switch (scmnd->cmnd[0]) {
1046		case ATA_16:
1047		case ATA_12:
1048			set_host_byte(scmnd, DID_PASSTHROUGH);
1049			break;
1050		/*
1051		 * On some Hyper-V hosts TEST_UNIT_READY command can
1052		 * return SRB_STATUS_ERROR. Let the upper level code
1053		 * deal with it based on the sense information.
1054		 */
1055		case TEST_UNIT_READY:
1056			break;
1057		default:
1058			set_host_byte(scmnd, DID_ERROR);
1059		}
1060		return;
1061
1062	case SRB_STATUS_INVALID_LUN:
1063		set_host_byte(scmnd, DID_NO_CONNECT);
1064		process_err_fn = storvsc_remove_lun;
1065		goto do_work;
1066
1067	}
1068	return;
1069
1070do_work:
1071	/*
1072	 * We need to schedule work to process this error; schedule it.
1073	 */
1074	wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1075	if (!wrk) {
1076		set_host_byte(scmnd, DID_TARGET_FAILURE);
1077		return;
1078	}
1079
1080	wrk->host = host;
1081	wrk->lun = vm_srb->lun;
1082	wrk->tgt_id = vm_srb->target_id;
1083	INIT_WORK(&wrk->work, process_err_fn);
1084	queue_work(host_dev->handle_error_wq, &wrk->work);
1085}
1086
1087
1088static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1089				       struct storvsc_device *stor_dev)
1090{
1091	struct scsi_cmnd *scmnd = cmd_request->cmd;
1092	struct scsi_sense_hdr sense_hdr;
1093	struct vmscsi_request *vm_srb;
1094	u32 data_transfer_length;
1095	struct Scsi_Host *host;
1096	u32 payload_sz = cmd_request->payload_sz;
1097	void *payload = cmd_request->payload;
1098
1099	host = stor_dev->host;
1100
1101	vm_srb = &cmd_request->vstor_packet.vm_srb;
1102	data_transfer_length = vm_srb->data_transfer_length;
1103
1104	scmnd->result = vm_srb->scsi_status;
1105
1106	if (scmnd->result) {
1107		if (scsi_normalize_sense(scmnd->sense_buffer,
1108				SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1109		    !(sense_hdr.sense_key == NOT_READY &&
1110				 sense_hdr.asc == 0x03A) &&
1111		    do_logging(STORVSC_LOGGING_ERROR))
1112			scsi_print_sense_hdr(scmnd->device, "storvsc",
1113					     &sense_hdr);
1114	}
1115
1116	if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1117		storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1118					 sense_hdr.ascq);
1119		/*
1120		 * The Windows driver set data_transfer_length on
1121		 * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1122		 * is untouched.  In these cases we set it to 0.
1123		 */
1124		if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1125			data_transfer_length = 0;
1126	}
1127
1128	/* Validate data_transfer_length (from Hyper-V) */
1129	if (data_transfer_length > cmd_request->payload->range.len)
1130		data_transfer_length = cmd_request->payload->range.len;
1131
1132	scsi_set_resid(scmnd,
1133		cmd_request->payload->range.len - data_transfer_length);
1134
1135	scmnd->scsi_done(scmnd);
1136
1137	if (payload_sz >
1138		sizeof(struct vmbus_channel_packet_multipage_buffer))
1139		kfree(payload);
1140}
1141
1142static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1143				  struct vstor_packet *vstor_packet,
1144				  struct storvsc_cmd_request *request)
1145{
1146	struct vstor_packet *stor_pkt;
1147	struct hv_device *device = stor_device->device;
1148
1149	stor_pkt = &request->vstor_packet;
1150
1151	/*
1152	 * The current SCSI handling on the host side does
1153	 * not correctly handle:
1154	 * INQUIRY command with page code parameter set to 0x80
1155	 * MODE_SENSE command with cmd[2] == 0x1c
1156	 *
1157	 * Setup srb and scsi status so this won't be fatal.
1158	 * We do this so we can distinguish truly fatal failues
1159	 * (srb status == 0x4) and off-line the device in that case.
1160	 */
1161
1162	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1163	   (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1164		vstor_packet->vm_srb.scsi_status = 0;
1165		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1166	}
1167
1168
1169	/* Copy over the status...etc */
1170	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1171	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1172
1173	/* Validate sense_info_length (from Hyper-V) */
1174	if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
1175		vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1176
1177	stor_pkt->vm_srb.sense_info_length =
1178	vstor_packet->vm_srb.sense_info_length;
1179
1180	if (vstor_packet->vm_srb.scsi_status != 0 ||
1181	    vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1182		storvsc_log(device, STORVSC_LOGGING_WARN,
1183			"cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1184			stor_pkt->vm_srb.cdb[0],
1185			vstor_packet->vm_srb.scsi_status,
1186			vstor_packet->vm_srb.srb_status);
1187
1188	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1189		/* CHECK_CONDITION */
1190		if (vstor_packet->vm_srb.srb_status &
1191			SRB_STATUS_AUTOSENSE_VALID) {
1192			/* autosense data available */
1193
1194			storvsc_log(device, STORVSC_LOGGING_WARN,
1195				"stor pkt %p autosense data valid - len %d\n",
1196				request, vstor_packet->vm_srb.sense_info_length);
1197
1198			memcpy(request->cmd->sense_buffer,
1199			       vstor_packet->vm_srb.sense_data,
1200			       vstor_packet->vm_srb.sense_info_length);
1201
1202		}
1203	}
1204
1205	stor_pkt->vm_srb.data_transfer_length =
1206	vstor_packet->vm_srb.data_transfer_length;
1207
1208	storvsc_command_completion(request, stor_device);
1209
1210	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1211		stor_device->drain_notify)
1212		wake_up(&stor_device->waiting_to_drain);
1213
1214
1215}
1216
1217static void storvsc_on_receive(struct storvsc_device *stor_device,
1218			     struct vstor_packet *vstor_packet,
1219			     struct storvsc_cmd_request *request)
1220{
1221	struct hv_host_device *host_dev;
1222	switch (vstor_packet->operation) {
1223	case VSTOR_OPERATION_COMPLETE_IO:
1224		storvsc_on_io_completion(stor_device, vstor_packet, request);
1225		break;
1226
1227	case VSTOR_OPERATION_REMOVE_DEVICE:
1228	case VSTOR_OPERATION_ENUMERATE_BUS:
1229		host_dev = shost_priv(stor_device->host);
1230		queue_work(
1231			host_dev->handle_error_wq, &host_dev->host_scan_work);
1232		break;
1233
1234	case VSTOR_OPERATION_FCHBA_DATA:
1235		cache_wwn(stor_device, vstor_packet);
1236#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1237		fc_host_node_name(stor_device->host) = stor_device->node_name;
1238		fc_host_port_name(stor_device->host) = stor_device->port_name;
1239#endif
1240		break;
1241	default:
1242		break;
1243	}
1244}
1245
1246static void storvsc_on_channel_callback(void *context)
1247{
1248	struct vmbus_channel *channel = (struct vmbus_channel *)context;
1249	const struct vmpacket_descriptor *desc;
1250	struct hv_device *device;
1251	struct storvsc_device *stor_device;
1252
1253	if (channel->primary_channel != NULL)
1254		device = channel->primary_channel->device_obj;
1255	else
1256		device = channel->device_obj;
1257
1258	stor_device = get_in_stor_device(device);
1259	if (!stor_device)
1260		return;
1261
1262	foreach_vmbus_pkt(desc, channel) {
1263		void *packet = hv_pkt_data(desc);
1264		struct storvsc_cmd_request *request;
1265
1266		request = (struct storvsc_cmd_request *)
1267			((unsigned long)desc->trans_id);
1268
1269		if (request == &stor_device->init_request ||
1270		    request == &stor_device->reset_request) {
1271			memcpy(&request->vstor_packet, packet,
1272			       (sizeof(struct vstor_packet) - vmscsi_size_delta));
1273			complete(&request->wait_event);
1274		} else {
1275			storvsc_on_receive(stor_device, packet, request);
1276		}
1277	}
1278}
1279
1280static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1281				  bool is_fc)
1282{
1283	struct vmstorage_channel_properties props;
1284	int ret;
1285
1286	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1287
1288	ret = vmbus_open(device->channel,
1289			 ring_size,
1290			 ring_size,
1291			 (void *)&props,
1292			 sizeof(struct vmstorage_channel_properties),
1293			 storvsc_on_channel_callback, device->channel);
1294
1295	if (ret != 0)
1296		return ret;
1297
1298	ret = storvsc_channel_init(device, is_fc);
1299
1300	return ret;
1301}
1302
1303static int storvsc_dev_remove(struct hv_device *device)
1304{
1305	struct storvsc_device *stor_device;
1306
1307	stor_device = hv_get_drvdata(device);
1308
1309	stor_device->destroy = true;
1310
1311	/* Make sure flag is set before waiting */
1312	wmb();
1313
1314	/*
1315	 * At this point, all outbound traffic should be disable. We
1316	 * only allow inbound traffic (responses) to proceed so that
1317	 * outstanding requests can be completed.
1318	 */
1319
1320	storvsc_wait_to_drain(stor_device);
1321
1322	/*
1323	 * Since we have already drained, we don't need to busy wait
1324	 * as was done in final_release_stor_device()
1325	 * Note that we cannot set the ext pointer to NULL until
1326	 * we have drained - to drain the outgoing packets, we need to
1327	 * allow incoming packets.
1328	 */
1329	hv_set_drvdata(device, NULL);
1330
1331	/* Close the channel */
1332	vmbus_close(device->channel);
1333
1334	kfree(stor_device->stor_chns);
1335	kfree(stor_device);
1336	return 0;
1337}
1338
1339static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1340					u16 q_num)
1341{
1342	u16 slot = 0;
1343	u16 hash_qnum;
1344	const struct cpumask *node_mask;
1345	int num_channels, tgt_cpu;
1346
1347	if (stor_device->num_sc == 0) {
1348		stor_device->stor_chns[q_num] = stor_device->device->channel;
1349		return stor_device->device->channel;
1350	}
1351
1352	/*
1353	 * Our channel array is sparsley populated and we
1354	 * initiated I/O on a processor/hw-q that does not
1355	 * currently have a designated channel. Fix this.
1356	 * The strategy is simple:
1357	 * I. Ensure NUMA locality
1358	 * II. Distribute evenly (best effort)
1359	 */
1360
1361	node_mask = cpumask_of_node(cpu_to_node(q_num));
1362
1363	num_channels = 0;
1364	for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1365		if (cpumask_test_cpu(tgt_cpu, node_mask))
1366			num_channels++;
1367	}
1368	if (num_channels == 0) {
1369		stor_device->stor_chns[q_num] = stor_device->device->channel;
1370		return stor_device->device->channel;
1371	}
1372
1373	hash_qnum = q_num;
1374	while (hash_qnum >= num_channels)
1375		hash_qnum -= num_channels;
1376
1377	for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1378		if (!cpumask_test_cpu(tgt_cpu, node_mask))
1379			continue;
1380		if (slot == hash_qnum)
1381			break;
1382		slot++;
1383	}
1384
1385	stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1386
1387	return stor_device->stor_chns[q_num];
1388}
1389
1390
1391static int storvsc_do_io(struct hv_device *device,
1392			 struct storvsc_cmd_request *request, u16 q_num)
1393{
1394	struct storvsc_device *stor_device;
1395	struct vstor_packet *vstor_packet;
1396	struct vmbus_channel *outgoing_channel, *channel;
1397	unsigned long flags;
1398	int ret = 0;
1399	const struct cpumask *node_mask;
1400	int tgt_cpu;
1401
1402	vstor_packet = &request->vstor_packet;
1403	stor_device = get_out_stor_device(device);
1404
1405	if (!stor_device)
1406		return -ENODEV;
1407
1408
1409	request->device  = device;
1410	/*
1411	 * Select an appropriate channel to send the request out.
1412	 */
1413	/* See storvsc_change_target_cpu(). */
1414	outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1415	if (outgoing_channel != NULL) {
1416		if (outgoing_channel->target_cpu == q_num) {
1417			/*
1418			 * Ideally, we want to pick a different channel if
1419			 * available on the same NUMA node.
1420			 */
1421			node_mask = cpumask_of_node(cpu_to_node(q_num));
1422			for_each_cpu_wrap(tgt_cpu,
1423				 &stor_device->alloced_cpus, q_num + 1) {
1424				if (!cpumask_test_cpu(tgt_cpu, node_mask))
1425					continue;
1426				if (tgt_cpu == q_num)
1427					continue;
1428				channel = READ_ONCE(
1429					stor_device->stor_chns[tgt_cpu]);
1430				if (channel == NULL)
1431					continue;
1432				if (hv_get_avail_to_write_percent(
1433							&channel->outbound)
1434						> ring_avail_percent_lowater) {
1435					outgoing_channel = channel;
1436					goto found_channel;
1437				}
1438			}
1439
1440			/*
1441			 * All the other channels on the same NUMA node are
1442			 * busy. Try to use the channel on the current CPU
1443			 */
1444			if (hv_get_avail_to_write_percent(
1445						&outgoing_channel->outbound)
1446					> ring_avail_percent_lowater)
1447				goto found_channel;
1448
1449			/*
1450			 * If we reach here, all the channels on the current
1451			 * NUMA node are busy. Try to find a channel in
1452			 * other NUMA nodes
1453			 */
1454			for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1455				if (cpumask_test_cpu(tgt_cpu, node_mask))
1456					continue;
1457				channel = READ_ONCE(
1458					stor_device->stor_chns[tgt_cpu]);
1459				if (channel == NULL)
1460					continue;
1461				if (hv_get_avail_to_write_percent(
1462							&channel->outbound)
1463						> ring_avail_percent_lowater) {
1464					outgoing_channel = channel;
1465					goto found_channel;
1466				}
1467			}
1468		}
1469	} else {
1470		spin_lock_irqsave(&stor_device->lock, flags);
1471		outgoing_channel = stor_device->stor_chns[q_num];
1472		if (outgoing_channel != NULL) {
1473			spin_unlock_irqrestore(&stor_device->lock, flags);
1474			goto found_channel;
1475		}
1476		outgoing_channel = get_og_chn(stor_device, q_num);
1477		spin_unlock_irqrestore(&stor_device->lock, flags);
1478	}
1479
1480found_channel:
1481	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1482
1483	vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1484					vmscsi_size_delta);
1485
1486
1487	vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1488
1489
1490	vstor_packet->vm_srb.data_transfer_length =
1491	request->payload->range.len;
1492
1493	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1494
1495	if (request->payload->range.len) {
1496
1497		ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1498				request->payload, request->payload_sz,
1499				vstor_packet,
1500				(sizeof(struct vstor_packet) -
1501				vmscsi_size_delta),
1502				(unsigned long)request);
1503	} else {
1504		ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1505			       (sizeof(struct vstor_packet) -
1506				vmscsi_size_delta),
1507			       (unsigned long)request,
1508			       VM_PKT_DATA_INBAND,
1509			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1510	}
1511
1512	if (ret != 0)
1513		return ret;
1514
1515	atomic_inc(&stor_device->num_outstanding_req);
1516
1517	return ret;
1518}
1519
1520static int storvsc_device_alloc(struct scsi_device *sdevice)
1521{
1522	/*
1523	 * Set blist flag to permit the reading of the VPD pages even when
1524	 * the target may claim SPC-2 compliance. MSFT targets currently
1525	 * claim SPC-2 compliance while they implement post SPC-2 features.
1526	 * With this flag we can correctly handle WRITE_SAME_16 issues.
1527	 *
1528	 * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1529	 * still supports REPORT LUN.
1530	 */
1531	sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1532
1533	return 0;
1534}
1535
1536static int storvsc_device_configure(struct scsi_device *sdevice)
1537{
1538	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1539
1540	/* storvsc devices don't support MAINTENANCE_IN SCSI cmd */
1541	sdevice->no_report_opcodes = 1;
1542	sdevice->no_write_same = 1;
1543
1544	/*
1545	 * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1546	 * if the device is a MSFT virtual device.  If the host is
1547	 * WIN10 or newer, allow write_same.
1548	 */
1549	if (!strncmp(sdevice->vendor, "Msft", 4)) {
1550		switch (vmstor_proto_version) {
1551		case VMSTOR_PROTO_VERSION_WIN8:
1552		case VMSTOR_PROTO_VERSION_WIN8_1:
1553			sdevice->scsi_level = SCSI_SPC_3;
1554			break;
1555		}
1556
1557		if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1558			sdevice->no_write_same = 0;
1559	}
1560
1561	return 0;
1562}
1563
1564static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1565			   sector_t capacity, int *info)
1566{
1567	sector_t nsect = capacity;
1568	sector_t cylinders = nsect;
1569	int heads, sectors_pt;
1570
1571	/*
1572	 * We are making up these values; let us keep it simple.
1573	 */
1574	heads = 0xff;
1575	sectors_pt = 0x3f;      /* Sectors per track */
1576	sector_div(cylinders, heads * sectors_pt);
1577	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1578		cylinders = 0xffff;
1579
1580	info[0] = heads;
1581	info[1] = sectors_pt;
1582	info[2] = (int)cylinders;
1583
1584	return 0;
1585}
1586
1587static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1588{
1589	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1590	struct hv_device *device = host_dev->dev;
1591
1592	struct storvsc_device *stor_device;
1593	struct storvsc_cmd_request *request;
1594	struct vstor_packet *vstor_packet;
1595	int ret, t;
1596
1597
1598	stor_device = get_out_stor_device(device);
1599	if (!stor_device)
1600		return FAILED;
1601
1602	request = &stor_device->reset_request;
1603	vstor_packet = &request->vstor_packet;
1604	memset(vstor_packet, 0, sizeof(struct vstor_packet));
1605
1606	init_completion(&request->wait_event);
1607
1608	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1609	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1610	vstor_packet->vm_srb.path_id = stor_device->path_id;
1611
1612	ret = vmbus_sendpacket(device->channel, vstor_packet,
1613			       (sizeof(struct vstor_packet) -
1614				vmscsi_size_delta),
1615			       (unsigned long)&stor_device->reset_request,
1616			       VM_PKT_DATA_INBAND,
1617			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1618	if (ret != 0)
1619		return FAILED;
1620
1621	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1622	if (t == 0)
1623		return TIMEOUT_ERROR;
1624
1625
1626	/*
1627	 * At this point, all outstanding requests in the adapter
1628	 * should have been flushed out and return to us
1629	 * There is a potential race here where the host may be in
1630	 * the process of responding when we return from here.
1631	 * Just wait for all in-transit packets to be accounted for
1632	 * before we return from here.
1633	 */
1634	storvsc_wait_to_drain(stor_device);
1635
1636	return SUCCESS;
1637}
1638
1639/*
1640 * The host guarantees to respond to each command, although I/O latencies might
1641 * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1642 * chance to perform EH.
1643 */
1644static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1645{
1646	return BLK_EH_RESET_TIMER;
1647}
1648
1649static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1650{
1651	bool allowed = true;
1652	u8 scsi_op = scmnd->cmnd[0];
1653
1654	switch (scsi_op) {
1655	/* the host does not handle WRITE_SAME, log accident usage */
1656	case WRITE_SAME:
1657	/*
1658	 * smartd sends this command and the host does not handle
1659	 * this. So, don't send it.
1660	 */
1661	case SET_WINDOW:
1662		scmnd->result = ILLEGAL_REQUEST << 16;
1663		allowed = false;
1664		break;
1665	default:
1666		break;
1667	}
1668	return allowed;
1669}
1670
1671static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1672{
1673	int ret;
1674	struct hv_host_device *host_dev = shost_priv(host);
1675	struct hv_device *dev = host_dev->dev;
1676	struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1677	int i;
1678	struct scatterlist *sgl;
1679	unsigned int sg_count = 0;
1680	struct vmscsi_request *vm_srb;
1681	struct scatterlist *cur_sgl;
1682	struct vmbus_packet_mpb_array  *payload;
1683	u32 payload_sz;
1684	u32 length;
1685
1686	if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1687		/*
1688		 * On legacy hosts filter unimplemented commands.
1689		 * Future hosts are expected to correctly handle
1690		 * unsupported commands. Furthermore, it is
1691		 * possible that some of the currently
1692		 * unsupported commands maybe supported in
1693		 * future versions of the host.
1694		 */
1695		if (!storvsc_scsi_cmd_ok(scmnd)) {
1696			scmnd->scsi_done(scmnd);
1697			return 0;
1698		}
1699	}
1700
1701	/* Setup the cmd request */
1702	cmd_request->cmd = scmnd;
1703
1704	memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1705	vm_srb = &cmd_request->vstor_packet.vm_srb;
1706	vm_srb->win8_extension.time_out_value = 60;
1707
1708	vm_srb->win8_extension.srb_flags |=
1709		SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1710
1711	if (scmnd->device->tagged_supported) {
1712		vm_srb->win8_extension.srb_flags |=
1713		(SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1714		vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1715		vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1716	}
1717
1718	/* Build the SRB */
1719	switch (scmnd->sc_data_direction) {
1720	case DMA_TO_DEVICE:
1721		vm_srb->data_in = WRITE_TYPE;
1722		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1723		break;
1724	case DMA_FROM_DEVICE:
1725		vm_srb->data_in = READ_TYPE;
1726		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1727		break;
1728	case DMA_NONE:
1729		vm_srb->data_in = UNKNOWN_TYPE;
1730		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1731		break;
1732	default:
1733		/*
1734		 * This is DMA_BIDIRECTIONAL or something else we are never
1735		 * supposed to see here.
1736		 */
1737		WARN(1, "Unexpected data direction: %d\n",
1738		     scmnd->sc_data_direction);
1739		return -EINVAL;
1740	}
1741
1742
1743	vm_srb->port_number = host_dev->port;
1744	vm_srb->path_id = scmnd->device->channel;
1745	vm_srb->target_id = scmnd->device->id;
1746	vm_srb->lun = scmnd->device->lun;
1747
1748	vm_srb->cdb_length = scmnd->cmd_len;
1749
1750	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1751
1752	sgl = (struct scatterlist *)scsi_sglist(scmnd);
1753	sg_count = scsi_sg_count(scmnd);
1754
1755	length = scsi_bufflen(scmnd);
1756	payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1757	payload_sz = 0;
1758
1759	if (sg_count) {
1760		unsigned int hvpgoff = 0;
1761		unsigned long offset_in_hvpg = sgl->offset & ~HV_HYP_PAGE_MASK;
1762		unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1763		u64 hvpfn;
1764
1765		payload_sz = (hvpg_count * sizeof(u64) +
1766			      sizeof(struct vmbus_packet_mpb_array));
1767
1768		if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1769			payload = kzalloc(payload_sz, GFP_ATOMIC);
1770			if (!payload)
1771				return SCSI_MLQUEUE_DEVICE_BUSY;
1772		}
1773
1774		/*
1775		 * sgl is a list of PAGEs, and payload->range.pfn_array
1776		 * expects the page number in the unit of HV_HYP_PAGE_SIZE (the
1777		 * page size that Hyper-V uses, so here we need to divide PAGEs
1778		 * into HV_HYP_PAGE in case that PAGE_SIZE > HV_HYP_PAGE_SIZE.
1779		 * Besides, payload->range.offset should be the offset in one
1780		 * HV_HYP_PAGE.
1781		 */
1782		payload->range.len = length;
1783		payload->range.offset = offset_in_hvpg;
1784		hvpgoff = sgl->offset >> HV_HYP_PAGE_SHIFT;
1785
1786		cur_sgl = sgl;
1787		for (i = 0; i < hvpg_count; i++) {
1788			/*
1789			 * 'i' is the index of hv pages in the payload and
1790			 * 'hvpgoff' is the offset (in hv pages) of the first
1791			 * hv page in the the first page. The relationship
1792			 * between the sum of 'i' and 'hvpgoff' and the offset
1793			 * (in hv pages) in a payload page ('hvpgoff_in_page')
1794			 * is as follow:
1795			 *
1796			 * |------------------ PAGE -------------------|
1797			 * |   NR_HV_HYP_PAGES_IN_PAGE hvpgs in total  |
1798			 * |hvpg|hvpg| ...              |hvpg|... |hvpg|
1799			 * ^         ^                                 ^                 ^
1800			 * +-hvpgoff-+                                 +-hvpgoff_in_page-+
1801			 *           ^                                                   |
1802			 *           +--------------------- i ---------------------------+
1803			 */
1804			unsigned int hvpgoff_in_page =
1805				(i + hvpgoff) % NR_HV_HYP_PAGES_IN_PAGE;
1806
1807			/*
1808			 * Two cases that we need to fetch a page:
1809			 * 1) i == 0, the first step or
1810			 * 2) hvpgoff_in_page == 0, when we reach the boundary
1811			 *    of a page.
1812			 */
1813			if (hvpgoff_in_page == 0 || i == 0) {
1814				hvpfn = page_to_hvpfn(sg_page(cur_sgl));
1815				cur_sgl = sg_next(cur_sgl);
1816			}
1817
1818			payload->range.pfn_array[i] = hvpfn + hvpgoff_in_page;
1819		}
1820	}
1821
1822	cmd_request->payload = payload;
1823	cmd_request->payload_sz = payload_sz;
1824
1825	/* Invokes the vsc to start an IO */
1826	ret = storvsc_do_io(dev, cmd_request, get_cpu());
1827	put_cpu();
1828
1829	if (ret == -EAGAIN) {
1830		if (payload_sz > sizeof(cmd_request->mpb))
1831			kfree(payload);
1832		/* no more space */
1833		return SCSI_MLQUEUE_DEVICE_BUSY;
1834	}
1835
1836	return 0;
1837}
1838
1839static struct scsi_host_template scsi_driver = {
1840	.module	=		THIS_MODULE,
1841	.name =			"storvsc_host_t",
1842	.cmd_size =             sizeof(struct storvsc_cmd_request),
1843	.bios_param =		storvsc_get_chs,
1844	.queuecommand =		storvsc_queuecommand,
1845	.eh_host_reset_handler =	storvsc_host_reset_handler,
1846	.proc_name =		"storvsc_host",
1847	.eh_timed_out =		storvsc_eh_timed_out,
1848	.slave_alloc =		storvsc_device_alloc,
1849	.slave_configure =	storvsc_device_configure,
1850	.cmd_per_lun =		2048,
1851	.this_id =		-1,
1852	/* Make sure we dont get a sg segment crosses a page boundary */
1853	.dma_boundary =		PAGE_SIZE-1,
1854	/* Ensure there are no gaps in presented sgls */
1855	.virt_boundary_mask =	PAGE_SIZE-1,
1856	.no_write_same =	1,
1857	.track_queue_depth =	1,
1858	.change_queue_depth =	storvsc_change_queue_depth,
1859};
1860
1861enum {
1862	SCSI_GUID,
1863	IDE_GUID,
1864	SFC_GUID,
1865};
1866
1867static const struct hv_vmbus_device_id id_table[] = {
1868	/* SCSI guid */
1869	{ HV_SCSI_GUID,
1870	  .driver_data = SCSI_GUID
1871	},
1872	/* IDE guid */
1873	{ HV_IDE_GUID,
1874	  .driver_data = IDE_GUID
1875	},
1876	/* Fibre Channel GUID */
1877	{
1878	  HV_SYNTHFC_GUID,
1879	  .driver_data = SFC_GUID
1880	},
1881	{ },
1882};
1883
1884MODULE_DEVICE_TABLE(vmbus, id_table);
1885
1886static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1887
1888static bool hv_dev_is_fc(struct hv_device *hv_dev)
1889{
1890	return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1891}
1892
1893static int storvsc_probe(struct hv_device *device,
1894			const struct hv_vmbus_device_id *dev_id)
1895{
1896	int ret;
1897	int num_cpus = num_online_cpus();
1898	struct Scsi_Host *host;
1899	struct hv_host_device *host_dev;
1900	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1901	bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1902	int target = 0;
1903	struct storvsc_device *stor_device;
1904	int max_luns_per_target;
1905	int max_targets;
1906	int max_channels;
1907	int max_sub_channels = 0;
1908
1909	/*
1910	 * Based on the windows host we are running on,
1911	 * set state to properly communicate with the host.
1912	 */
1913
1914	if (vmbus_proto_version < VERSION_WIN8) {
1915		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1916		max_targets = STORVSC_IDE_MAX_TARGETS;
1917		max_channels = STORVSC_IDE_MAX_CHANNELS;
1918	} else {
1919		max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1920		max_targets = STORVSC_MAX_TARGETS;
1921		max_channels = STORVSC_MAX_CHANNELS;
1922		/*
1923		 * On Windows8 and above, we support sub-channels for storage
1924		 * on SCSI and FC controllers.
1925		 * The number of sub-channels offerred is based on the number of
1926		 * VCPUs in the guest.
1927		 */
1928		if (!dev_is_ide)
1929			max_sub_channels =
1930				(num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1931	}
1932
1933	scsi_driver.can_queue = max_outstanding_req_per_channel *
1934				(max_sub_channels + 1) *
1935				(100 - ring_avail_percent_lowater) / 100;
1936
1937	host = scsi_host_alloc(&scsi_driver,
1938			       sizeof(struct hv_host_device));
1939	if (!host)
1940		return -ENOMEM;
1941
1942	host_dev = shost_priv(host);
1943	memset(host_dev, 0, sizeof(struct hv_host_device));
1944
1945	host_dev->port = host->host_no;
1946	host_dev->dev = device;
1947	host_dev->host = host;
1948
1949
1950	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1951	if (!stor_device) {
1952		ret = -ENOMEM;
1953		goto err_out0;
1954	}
1955
1956	stor_device->destroy = false;
1957	init_waitqueue_head(&stor_device->waiting_to_drain);
1958	stor_device->device = device;
1959	stor_device->host = host;
1960	spin_lock_init(&stor_device->lock);
1961	hv_set_drvdata(device, stor_device);
1962
1963	stor_device->port_number = host->host_no;
1964	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1965	if (ret)
1966		goto err_out1;
1967
1968	host_dev->path = stor_device->path_id;
1969	host_dev->target = stor_device->target_id;
1970
1971	switch (dev_id->driver_data) {
1972	case SFC_GUID:
1973		host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1974		host->max_id = STORVSC_FC_MAX_TARGETS;
1975		host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1976#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1977		host->transportt = fc_transport_template;
1978#endif
1979		break;
1980
1981	case SCSI_GUID:
1982		host->max_lun = max_luns_per_target;
1983		host->max_id = max_targets;
1984		host->max_channel = max_channels - 1;
1985		break;
1986
1987	default:
1988		host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1989		host->max_id = STORVSC_IDE_MAX_TARGETS;
1990		host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1991		break;
1992	}
1993	/* max cmd length */
1994	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1995
1996	/*
1997	 * set the table size based on the info we got
1998	 * from the host.
1999	 */
2000	host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
2001	/*
2002	 * For non-IDE disks, the host supports multiple channels.
2003	 * Set the number of HW queues we are supporting.
2004	 */
2005	if (!dev_is_ide)
2006		host->nr_hw_queues = num_present_cpus();
2007
2008	/*
2009	 * Set the error handler work queue.
2010	 */
2011	host_dev->handle_error_wq =
2012			alloc_ordered_workqueue("storvsc_error_wq_%d",
2013						0,
2014						host->host_no);
2015	if (!host_dev->handle_error_wq) {
2016		ret = -ENOMEM;
2017		goto err_out2;
2018	}
2019	INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2020	/* Register the HBA and start the scsi bus scan */
2021	ret = scsi_add_host(host, &device->device);
2022	if (ret != 0)
2023		goto err_out3;
2024
2025	if (!dev_is_ide) {
2026		scsi_scan_host(host);
2027	} else {
2028		target = (device->dev_instance.b[5] << 8 |
2029			 device->dev_instance.b[4]);
2030		ret = scsi_add_device(host, 0, target, 0);
2031		if (ret)
2032			goto err_out4;
2033	}
2034#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2035	if (host->transportt == fc_transport_template) {
2036		struct fc_rport_identifiers ids = {
2037			.roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2038		};
2039
2040		fc_host_node_name(host) = stor_device->node_name;
2041		fc_host_port_name(host) = stor_device->port_name;
2042		stor_device->rport = fc_remote_port_add(host, 0, &ids);
2043		if (!stor_device->rport) {
2044			ret = -ENOMEM;
2045			goto err_out4;
2046		}
2047	}
2048#endif
2049	return 0;
2050
2051err_out4:
2052	scsi_remove_host(host);
2053
2054err_out3:
2055	destroy_workqueue(host_dev->handle_error_wq);
2056
2057err_out2:
2058	/*
2059	 * Once we have connected with the host, we would need to
2060	 * to invoke storvsc_dev_remove() to rollback this state and
2061	 * this call also frees up the stor_device; hence the jump around
2062	 * err_out1 label.
2063	 */
2064	storvsc_dev_remove(device);
2065	goto err_out0;
2066
2067err_out1:
2068	kfree(stor_device->stor_chns);
2069	kfree(stor_device);
2070
2071err_out0:
2072	scsi_host_put(host);
2073	return ret;
2074}
2075
2076/* Change a scsi target's queue depth */
2077static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2078{
2079	if (queue_depth > scsi_driver.can_queue)
2080		queue_depth = scsi_driver.can_queue;
2081
2082	return scsi_change_queue_depth(sdev, queue_depth);
2083}
2084
2085static int storvsc_remove(struct hv_device *dev)
2086{
2087	struct storvsc_device *stor_device = hv_get_drvdata(dev);
2088	struct Scsi_Host *host = stor_device->host;
2089	struct hv_host_device *host_dev = shost_priv(host);
2090
2091#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2092	if (host->transportt == fc_transport_template) {
2093		fc_remote_port_delete(stor_device->rport);
2094		fc_remove_host(host);
2095	}
2096#endif
2097	destroy_workqueue(host_dev->handle_error_wq);
2098	scsi_remove_host(host);
2099	storvsc_dev_remove(dev);
2100	scsi_host_put(host);
2101
2102	return 0;
2103}
2104
2105static int storvsc_suspend(struct hv_device *hv_dev)
2106{
2107	struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2108	struct Scsi_Host *host = stor_device->host;
2109	struct hv_host_device *host_dev = shost_priv(host);
2110
2111	storvsc_wait_to_drain(stor_device);
2112
2113	drain_workqueue(host_dev->handle_error_wq);
2114
2115	vmbus_close(hv_dev->channel);
2116
2117	kfree(stor_device->stor_chns);
2118	stor_device->stor_chns = NULL;
2119
2120	cpumask_clear(&stor_device->alloced_cpus);
2121
2122	return 0;
2123}
2124
2125static int storvsc_resume(struct hv_device *hv_dev)
2126{
2127	int ret;
2128
2129	ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2130				     hv_dev_is_fc(hv_dev));
2131	return ret;
2132}
2133
2134static struct hv_driver storvsc_drv = {
2135	.name = KBUILD_MODNAME,
2136	.id_table = id_table,
2137	.probe = storvsc_probe,
2138	.remove = storvsc_remove,
2139	.suspend = storvsc_suspend,
2140	.resume = storvsc_resume,
2141	.driver = {
2142		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
2143	},
2144};
2145
2146#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2147static struct fc_function_template fc_transport_functions = {
2148	.show_host_node_name = 1,
2149	.show_host_port_name = 1,
2150};
2151#endif
2152
2153static int __init storvsc_drv_init(void)
2154{
2155	int ret;
2156
2157	/*
2158	 * Divide the ring buffer data size (which is 1 page less
2159	 * than the ring buffer size since that page is reserved for
2160	 * the ring buffer indices) by the max request size (which is
2161	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2162	 */
2163	max_outstanding_req_per_channel =
2164		((storvsc_ringbuffer_size - PAGE_SIZE) /
2165		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2166		sizeof(struct vstor_packet) + sizeof(u64) -
2167		vmscsi_size_delta,
2168		sizeof(u64)));
2169
2170#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2171	fc_transport_template = fc_attach_transport(&fc_transport_functions);
2172	if (!fc_transport_template)
2173		return -ENODEV;
2174#endif
2175
2176	ret = vmbus_driver_register(&storvsc_drv);
2177
2178#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2179	if (ret)
2180		fc_release_transport(fc_transport_template);
2181#endif
2182
2183	return ret;
2184}
2185
2186static void __exit storvsc_drv_exit(void)
2187{
2188	vmbus_driver_unregister(&storvsc_drv);
2189#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2190	fc_release_transport(fc_transport_template);
2191#endif
2192}
2193
2194MODULE_LICENSE("GPL");
2195MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2196module_init(storvsc_drv_init);
2197module_exit(storvsc_drv_exit);
2198