xref: /linux/drivers/scsi/storvsc_drv.c (revision a8fe58cec351c25e09c393bf46117c0c47b5a17c)
1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  *   K. Y. Srinivasan <kys@microsoft.com>
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/wait.h>
25 #include <linux/sched.h>
26 #include <linux/completion.h>
27 #include <linux/string.h>
28 #include <linux/mm.h>
29 #include <linux/delay.h>
30 #include <linux/init.h>
31 #include <linux/slab.h>
32 #include <linux/module.h>
33 #include <linux/device.h>
34 #include <linux/hyperv.h>
35 #include <linux/blkdev.h>
36 #include <scsi/scsi.h>
37 #include <scsi/scsi_cmnd.h>
38 #include <scsi/scsi_host.h>
39 #include <scsi/scsi_device.h>
40 #include <scsi/scsi_tcq.h>
41 #include <scsi/scsi_eh.h>
42 #include <scsi/scsi_devinfo.h>
43 #include <scsi/scsi_dbg.h>
44 #include <scsi/scsi_transport_fc.h>
45 
46 /*
47  * All wire protocol details (storage protocol between the guest and the host)
48  * are consolidated here.
49  *
50  * Begin protocol definitions.
51  */
52 
53 /*
54  * Version history:
55  * V1 Beta: 0.1
56  * V1 RC < 2008/1/31: 1.0
57  * V1 RC > 2008/1/31:  2.0
58  * Win7: 4.2
59  * Win8: 5.1
60  * Win8.1: 6.0
61  * Win10: 6.2
62  */
63 
64 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)	((((MAJOR_) & 0xff) << 8) | \
65 						(((MINOR_) & 0xff)))
66 
67 #define VMSTOR_PROTO_VERSION_WIN6	VMSTOR_PROTO_VERSION(2, 0)
68 #define VMSTOR_PROTO_VERSION_WIN7	VMSTOR_PROTO_VERSION(4, 2)
69 #define VMSTOR_PROTO_VERSION_WIN8	VMSTOR_PROTO_VERSION(5, 1)
70 #define VMSTOR_PROTO_VERSION_WIN8_1	VMSTOR_PROTO_VERSION(6, 0)
71 #define VMSTOR_PROTO_VERSION_WIN10	VMSTOR_PROTO_VERSION(6, 2)
72 
73 /*  Packet structure describing virtual storage requests. */
74 enum vstor_packet_operation {
75 	VSTOR_OPERATION_COMPLETE_IO		= 1,
76 	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
77 	VSTOR_OPERATION_EXECUTE_SRB		= 3,
78 	VSTOR_OPERATION_RESET_LUN		= 4,
79 	VSTOR_OPERATION_RESET_ADAPTER		= 5,
80 	VSTOR_OPERATION_RESET_BUS		= 6,
81 	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
82 	VSTOR_OPERATION_END_INITIALIZATION	= 8,
83 	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
84 	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
85 	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
86 	VSTOR_OPERATION_FCHBA_DATA              = 12,
87 	VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
88 	VSTOR_OPERATION_MAXIMUM                 = 13
89 };
90 
91 /*
92  * WWN packet for Fibre Channel HBA
93  */
94 
95 struct hv_fc_wwn_packet {
96 	u8	primary_active;
97 	u8	reserved1[3];
98 	u8	primary_port_wwn[8];
99 	u8	primary_node_wwn[8];
100 	u8	secondary_port_wwn[8];
101 	u8	secondary_node_wwn[8];
102 };
103 
104 
105 
106 /*
107  * SRB Flag Bits
108  */
109 
110 #define SRB_FLAGS_QUEUE_ACTION_ENABLE		0x00000002
111 #define SRB_FLAGS_DISABLE_DISCONNECT		0x00000004
112 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER	0x00000008
113 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE		0x00000010
114 #define SRB_FLAGS_DISABLE_AUTOSENSE		0x00000020
115 #define SRB_FLAGS_DATA_IN			0x00000040
116 #define SRB_FLAGS_DATA_OUT			0x00000080
117 #define SRB_FLAGS_NO_DATA_TRANSFER		0x00000000
118 #define SRB_FLAGS_UNSPECIFIED_DIRECTION	(SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
119 #define SRB_FLAGS_NO_QUEUE_FREEZE		0x00000100
120 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE		0x00000200
121 #define SRB_FLAGS_FREE_SENSE_BUFFER		0x00000400
122 
123 /*
124  * This flag indicates the request is part of the workflow for processing a D3.
125  */
126 #define SRB_FLAGS_D3_PROCESSING			0x00000800
127 #define SRB_FLAGS_IS_ACTIVE			0x00010000
128 #define SRB_FLAGS_ALLOCATED_FROM_ZONE		0x00020000
129 #define SRB_FLAGS_SGLIST_FROM_POOL		0x00040000
130 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE		0x00080000
131 #define SRB_FLAGS_NO_KEEP_AWAKE			0x00100000
132 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE	0x00200000
133 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT	0x00400000
134 #define SRB_FLAGS_DONT_START_NEXT_PACKET	0x00800000
135 #define SRB_FLAGS_PORT_DRIVER_RESERVED		0x0F000000
136 #define SRB_FLAGS_CLASS_DRIVER_RESERVED		0xF0000000
137 
138 
139 /*
140  * Platform neutral description of a scsi request -
141  * this remains the same across the write regardless of 32/64 bit
142  * note: it's patterned off the SCSI_PASS_THROUGH structure
143  */
144 #define STORVSC_MAX_CMD_LEN			0x10
145 
146 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE	0x14
147 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE	0x12
148 
149 #define STORVSC_SENSE_BUFFER_SIZE		0x14
150 #define STORVSC_MAX_BUF_LEN_WITH_PADDING	0x14
151 
152 /*
153  * Sense buffer size changed in win8; have a run-time
154  * variable to track the size we should use.  This value will
155  * likely change during protocol negotiation but it is valid
156  * to start by assuming pre-Win8.
157  */
158 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
159 
160 /*
161  * The storage protocol version is determined during the
162  * initial exchange with the host.  It will indicate which
163  * storage functionality is available in the host.
164 */
165 static int vmstor_proto_version;
166 
167 #define STORVSC_LOGGING_NONE	0
168 #define STORVSC_LOGGING_ERROR	1
169 #define STORVSC_LOGGING_WARN	2
170 
171 static int logging_level = STORVSC_LOGGING_ERROR;
172 module_param(logging_level, int, S_IRUGO|S_IWUSR);
173 MODULE_PARM_DESC(logging_level,
174 	"Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
175 
176 static inline bool do_logging(int level)
177 {
178 	return logging_level >= level;
179 }
180 
181 #define storvsc_log(dev, level, fmt, ...)			\
182 do {								\
183 	if (do_logging(level))					\
184 		dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);	\
185 } while (0)
186 
187 struct vmscsi_win8_extension {
188 	/*
189 	 * The following were added in Windows 8
190 	 */
191 	u16 reserve;
192 	u8  queue_tag;
193 	u8  queue_action;
194 	u32 srb_flags;
195 	u32 time_out_value;
196 	u32 queue_sort_ey;
197 } __packed;
198 
199 struct vmscsi_request {
200 	u16 length;
201 	u8 srb_status;
202 	u8 scsi_status;
203 
204 	u8  port_number;
205 	u8  path_id;
206 	u8  target_id;
207 	u8  lun;
208 
209 	u8  cdb_length;
210 	u8  sense_info_length;
211 	u8  data_in;
212 	u8  reserved;
213 
214 	u32 data_transfer_length;
215 
216 	union {
217 		u8 cdb[STORVSC_MAX_CMD_LEN];
218 		u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
219 		u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
220 	};
221 	/*
222 	 * The following was added in win8.
223 	 */
224 	struct vmscsi_win8_extension win8_extension;
225 
226 } __attribute((packed));
227 
228 
229 /*
230  * The size of the vmscsi_request has changed in win8. The
231  * additional size is because of new elements added to the
232  * structure. These elements are valid only when we are talking
233  * to a win8 host.
234  * Track the correction to size we need to apply. This value
235  * will likely change during protocol negotiation but it is
236  * valid to start by assuming pre-Win8.
237  */
238 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
239 
240 /*
241  * The list of storage protocols in order of preference.
242  */
243 struct vmstor_protocol {
244 	int protocol_version;
245 	int sense_buffer_size;
246 	int vmscsi_size_delta;
247 };
248 
249 
250 static const struct vmstor_protocol vmstor_protocols[] = {
251 	{
252 		VMSTOR_PROTO_VERSION_WIN10,
253 		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
254 		0
255 	},
256 	{
257 		VMSTOR_PROTO_VERSION_WIN8_1,
258 		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
259 		0
260 	},
261 	{
262 		VMSTOR_PROTO_VERSION_WIN8,
263 		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
264 		0
265 	},
266 	{
267 		VMSTOR_PROTO_VERSION_WIN7,
268 		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
269 		sizeof(struct vmscsi_win8_extension),
270 	},
271 	{
272 		VMSTOR_PROTO_VERSION_WIN6,
273 		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
274 		sizeof(struct vmscsi_win8_extension),
275 	}
276 };
277 
278 
279 /*
280  * This structure is sent during the intialization phase to get the different
281  * properties of the channel.
282  */
283 
284 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL		0x1
285 
286 struct vmstorage_channel_properties {
287 	u32 reserved;
288 	u16 max_channel_cnt;
289 	u16 reserved1;
290 
291 	u32 flags;
292 	u32   max_transfer_bytes;
293 
294 	u64  reserved2;
295 } __packed;
296 
297 /*  This structure is sent during the storage protocol negotiations. */
298 struct vmstorage_protocol_version {
299 	/* Major (MSW) and minor (LSW) version numbers. */
300 	u16 major_minor;
301 
302 	/*
303 	 * Revision number is auto-incremented whenever this file is changed
304 	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
305 	 * definitely indicate incompatibility--but it does indicate mismatched
306 	 * builds.
307 	 * This is only used on the windows side. Just set it to 0.
308 	 */
309 	u16 revision;
310 } __packed;
311 
312 /* Channel Property Flags */
313 #define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
314 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
315 
316 struct vstor_packet {
317 	/* Requested operation type */
318 	enum vstor_packet_operation operation;
319 
320 	/*  Flags - see below for values */
321 	u32 flags;
322 
323 	/* Status of the request returned from the server side. */
324 	u32 status;
325 
326 	/* Data payload area */
327 	union {
328 		/*
329 		 * Structure used to forward SCSI commands from the
330 		 * client to the server.
331 		 */
332 		struct vmscsi_request vm_srb;
333 
334 		/* Structure used to query channel properties. */
335 		struct vmstorage_channel_properties storage_channel_properties;
336 
337 		/* Used during version negotiations. */
338 		struct vmstorage_protocol_version version;
339 
340 		/* Fibre channel address packet */
341 		struct hv_fc_wwn_packet wwn_packet;
342 
343 		/* Number of sub-channels to create */
344 		u16 sub_channel_count;
345 
346 		/* This will be the maximum of the union members */
347 		u8  buffer[0x34];
348 	};
349 } __packed;
350 
351 /*
352  * Packet Flags:
353  *
354  * This flag indicates that the server should send back a completion for this
355  * packet.
356  */
357 
358 #define REQUEST_COMPLETION_FLAG	0x1
359 
360 /* Matches Windows-end */
361 enum storvsc_request_type {
362 	WRITE_TYPE = 0,
363 	READ_TYPE,
364 	UNKNOWN_TYPE,
365 };
366 
367 /*
368  * SRB status codes and masks; a subset of the codes used here.
369  */
370 
371 #define SRB_STATUS_AUTOSENSE_VALID	0x80
372 #define SRB_STATUS_QUEUE_FROZEN		0x40
373 #define SRB_STATUS_INVALID_LUN	0x20
374 #define SRB_STATUS_SUCCESS	0x01
375 #define SRB_STATUS_ABORTED	0x02
376 #define SRB_STATUS_ERROR	0x04
377 
378 #define SRB_STATUS(status) \
379 	(status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
380 /*
381  * This is the end of Protocol specific defines.
382  */
383 
384 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
385 static u32 max_outstanding_req_per_channel;
386 
387 static int storvsc_vcpus_per_sub_channel = 4;
388 
389 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
390 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
391 
392 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
393 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
394 /*
395  * Timeout in seconds for all devices managed by this driver.
396  */
397 static int storvsc_timeout = 180;
398 
399 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
400 
401 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
402 static struct scsi_transport_template *fc_transport_template;
403 #endif
404 
405 static void storvsc_on_channel_callback(void *context);
406 
407 #define STORVSC_MAX_LUNS_PER_TARGET			255
408 #define STORVSC_MAX_TARGETS				2
409 #define STORVSC_MAX_CHANNELS				8
410 
411 #define STORVSC_FC_MAX_LUNS_PER_TARGET			255
412 #define STORVSC_FC_MAX_TARGETS				128
413 #define STORVSC_FC_MAX_CHANNELS				8
414 
415 #define STORVSC_IDE_MAX_LUNS_PER_TARGET			64
416 #define STORVSC_IDE_MAX_TARGETS				1
417 #define STORVSC_IDE_MAX_CHANNELS			1
418 
419 struct storvsc_cmd_request {
420 	struct scsi_cmnd *cmd;
421 
422 	struct hv_device *device;
423 
424 	/* Synchronize the request/response if needed */
425 	struct completion wait_event;
426 
427 	struct vmbus_channel_packet_multipage_buffer mpb;
428 	struct vmbus_packet_mpb_array *payload;
429 	u32 payload_sz;
430 
431 	struct vstor_packet vstor_packet;
432 };
433 
434 
435 /* A storvsc device is a device object that contains a vmbus channel */
436 struct storvsc_device {
437 	struct hv_device *device;
438 
439 	bool	 destroy;
440 	bool	 drain_notify;
441 	bool	 open_sub_channel;
442 	atomic_t num_outstanding_req;
443 	struct Scsi_Host *host;
444 
445 	wait_queue_head_t waiting_to_drain;
446 
447 	/*
448 	 * Each unique Port/Path/Target represents 1 channel ie scsi
449 	 * controller. In reality, the pathid, targetid is always 0
450 	 * and the port is set by us
451 	 */
452 	unsigned int port_number;
453 	unsigned char path_id;
454 	unsigned char target_id;
455 
456 	/*
457 	 * Max I/O, the device can support.
458 	 */
459 	u32   max_transfer_bytes;
460 	/* Used for vsc/vsp channel reset process */
461 	struct storvsc_cmd_request init_request;
462 	struct storvsc_cmd_request reset_request;
463 	/*
464 	 * Currently active port and node names for FC devices.
465 	 */
466 	u64 node_name;
467 	u64 port_name;
468 };
469 
470 struct hv_host_device {
471 	struct hv_device *dev;
472 	unsigned int port;
473 	unsigned char path;
474 	unsigned char target;
475 };
476 
477 struct storvsc_scan_work {
478 	struct work_struct work;
479 	struct Scsi_Host *host;
480 	uint lun;
481 };
482 
483 static void storvsc_device_scan(struct work_struct *work)
484 {
485 	struct storvsc_scan_work *wrk;
486 	uint lun;
487 	struct scsi_device *sdev;
488 
489 	wrk = container_of(work, struct storvsc_scan_work, work);
490 	lun = wrk->lun;
491 
492 	sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
493 	if (!sdev)
494 		goto done;
495 	scsi_rescan_device(&sdev->sdev_gendev);
496 	scsi_device_put(sdev);
497 
498 done:
499 	kfree(wrk);
500 }
501 
502 static void storvsc_host_scan(struct work_struct *work)
503 {
504 	struct storvsc_scan_work *wrk;
505 	struct Scsi_Host *host;
506 	struct scsi_device *sdev;
507 
508 	wrk = container_of(work, struct storvsc_scan_work, work);
509 	host = wrk->host;
510 
511 	/*
512 	 * Before scanning the host, first check to see if any of the
513 	 * currrently known devices have been hot removed. We issue a
514 	 * "unit ready" command against all currently known devices.
515 	 * This I/O will result in an error for devices that have been
516 	 * removed. As part of handling the I/O error, we remove the device.
517 	 *
518 	 * When a LUN is added or removed, the host sends us a signal to
519 	 * scan the host. Thus we are forced to discover the LUNs that
520 	 * may have been removed this way.
521 	 */
522 	mutex_lock(&host->scan_mutex);
523 	shost_for_each_device(sdev, host)
524 		scsi_test_unit_ready(sdev, 1, 1, NULL);
525 	mutex_unlock(&host->scan_mutex);
526 	/*
527 	 * Now scan the host to discover LUNs that may have been added.
528 	 */
529 	scsi_scan_host(host);
530 
531 	kfree(wrk);
532 }
533 
534 static void storvsc_remove_lun(struct work_struct *work)
535 {
536 	struct storvsc_scan_work *wrk;
537 	struct scsi_device *sdev;
538 
539 	wrk = container_of(work, struct storvsc_scan_work, work);
540 	if (!scsi_host_get(wrk->host))
541 		goto done;
542 
543 	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
544 
545 	if (sdev) {
546 		scsi_remove_device(sdev);
547 		scsi_device_put(sdev);
548 	}
549 	scsi_host_put(wrk->host);
550 
551 done:
552 	kfree(wrk);
553 }
554 
555 
556 /*
557  * We can get incoming messages from the host that are not in response to
558  * messages that we have sent out. An example of this would be messages
559  * received by the guest to notify dynamic addition/removal of LUNs. To
560  * deal with potential race conditions where the driver may be in the
561  * midst of being unloaded when we might receive an unsolicited message
562  * from the host, we have implemented a mechanism to gurantee sequential
563  * consistency:
564  *
565  * 1) Once the device is marked as being destroyed, we will fail all
566  *    outgoing messages.
567  * 2) We permit incoming messages when the device is being destroyed,
568  *    only to properly account for messages already sent out.
569  */
570 
571 static inline struct storvsc_device *get_out_stor_device(
572 					struct hv_device *device)
573 {
574 	struct storvsc_device *stor_device;
575 
576 	stor_device = hv_get_drvdata(device);
577 
578 	if (stor_device && stor_device->destroy)
579 		stor_device = NULL;
580 
581 	return stor_device;
582 }
583 
584 
585 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
586 {
587 	dev->drain_notify = true;
588 	wait_event(dev->waiting_to_drain,
589 		   atomic_read(&dev->num_outstanding_req) == 0);
590 	dev->drain_notify = false;
591 }
592 
593 static inline struct storvsc_device *get_in_stor_device(
594 					struct hv_device *device)
595 {
596 	struct storvsc_device *stor_device;
597 
598 	stor_device = hv_get_drvdata(device);
599 
600 	if (!stor_device)
601 		goto get_in_err;
602 
603 	/*
604 	 * If the device is being destroyed; allow incoming
605 	 * traffic only to cleanup outstanding requests.
606 	 */
607 
608 	if (stor_device->destroy  &&
609 		(atomic_read(&stor_device->num_outstanding_req) == 0))
610 		stor_device = NULL;
611 
612 get_in_err:
613 	return stor_device;
614 
615 }
616 
617 static void handle_sc_creation(struct vmbus_channel *new_sc)
618 {
619 	struct hv_device *device = new_sc->primary_channel->device_obj;
620 	struct storvsc_device *stor_device;
621 	struct vmstorage_channel_properties props;
622 
623 	stor_device = get_out_stor_device(device);
624 	if (!stor_device)
625 		return;
626 
627 	if (stor_device->open_sub_channel == false)
628 		return;
629 
630 	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
631 
632 	vmbus_open(new_sc,
633 		   storvsc_ringbuffer_size,
634 		   storvsc_ringbuffer_size,
635 		   (void *)&props,
636 		   sizeof(struct vmstorage_channel_properties),
637 		   storvsc_on_channel_callback, new_sc);
638 }
639 
640 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
641 {
642 	struct storvsc_device *stor_device;
643 	int num_cpus = num_online_cpus();
644 	int num_sc;
645 	struct storvsc_cmd_request *request;
646 	struct vstor_packet *vstor_packet;
647 	int ret, t;
648 
649 	num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
650 	stor_device = get_out_stor_device(device);
651 	if (!stor_device)
652 		return;
653 
654 	request = &stor_device->init_request;
655 	vstor_packet = &request->vstor_packet;
656 
657 	stor_device->open_sub_channel = true;
658 	/*
659 	 * Establish a handler for dealing with subchannels.
660 	 */
661 	vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
662 
663 	/*
664 	 * Check to see if sub-channels have already been created. This
665 	 * can happen when this driver is re-loaded after unloading.
666 	 */
667 
668 	if (vmbus_are_subchannels_present(device->channel))
669 		return;
670 
671 	stor_device->open_sub_channel = false;
672 	/*
673 	 * Request the host to create sub-channels.
674 	 */
675 	memset(request, 0, sizeof(struct storvsc_cmd_request));
676 	init_completion(&request->wait_event);
677 	vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
678 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
679 	vstor_packet->sub_channel_count = num_sc;
680 
681 	ret = vmbus_sendpacket(device->channel, vstor_packet,
682 			       (sizeof(struct vstor_packet) -
683 			       vmscsi_size_delta),
684 			       (unsigned long)request,
685 			       VM_PKT_DATA_INBAND,
686 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
687 
688 	if (ret != 0)
689 		return;
690 
691 	t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
692 	if (t == 0)
693 		return;
694 
695 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
696 	    vstor_packet->status != 0)
697 		return;
698 
699 	/*
700 	 * Now that we created the sub-channels, invoke the check; this
701 	 * may trigger the callback.
702 	 */
703 	stor_device->open_sub_channel = true;
704 	vmbus_are_subchannels_present(device->channel);
705 }
706 
707 static void cache_wwn(struct storvsc_device *stor_device,
708 		      struct vstor_packet *vstor_packet)
709 {
710 	/*
711 	 * Cache the currently active port and node ww names.
712 	 */
713 	if (vstor_packet->wwn_packet.primary_active) {
714 		stor_device->node_name =
715 			wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
716 		stor_device->port_name =
717 			wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
718 	} else {
719 		stor_device->node_name =
720 			wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
721 		stor_device->port_name =
722 			wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
723 	}
724 }
725 
726 
727 static int storvsc_execute_vstor_op(struct hv_device *device,
728 				    struct storvsc_cmd_request *request,
729 				    bool status_check)
730 {
731 	struct vstor_packet *vstor_packet;
732 	int ret, t;
733 
734 	vstor_packet = &request->vstor_packet;
735 
736 	init_completion(&request->wait_event);
737 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
738 
739 	ret = vmbus_sendpacket(device->channel, vstor_packet,
740 			       (sizeof(struct vstor_packet) -
741 			       vmscsi_size_delta),
742 			       (unsigned long)request,
743 			       VM_PKT_DATA_INBAND,
744 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
745 	if (ret != 0)
746 		return ret;
747 
748 	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
749 	if (t == 0)
750 		return -ETIMEDOUT;
751 
752 	if (!status_check)
753 		return ret;
754 
755 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
756 	    vstor_packet->status != 0)
757 		return -EINVAL;
758 
759 	return ret;
760 }
761 
762 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
763 {
764 	struct storvsc_device *stor_device;
765 	struct storvsc_cmd_request *request;
766 	struct vstor_packet *vstor_packet;
767 	int ret, i;
768 	int max_chns;
769 	bool process_sub_channels = false;
770 
771 	stor_device = get_out_stor_device(device);
772 	if (!stor_device)
773 		return -ENODEV;
774 
775 	request = &stor_device->init_request;
776 	vstor_packet = &request->vstor_packet;
777 
778 	/*
779 	 * Now, initiate the vsc/vsp initialization protocol on the open
780 	 * channel
781 	 */
782 	memset(request, 0, sizeof(struct storvsc_cmd_request));
783 	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
784 	ret = storvsc_execute_vstor_op(device, request, true);
785 	if (ret)
786 		return ret;
787 	/*
788 	 * Query host supported protocol version.
789 	 */
790 
791 	for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
792 		/* reuse the packet for version range supported */
793 		memset(vstor_packet, 0, sizeof(struct vstor_packet));
794 		vstor_packet->operation =
795 			VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
796 
797 		vstor_packet->version.major_minor =
798 			vmstor_protocols[i].protocol_version;
799 
800 		/*
801 		 * The revision number is only used in Windows; set it to 0.
802 		 */
803 		vstor_packet->version.revision = 0;
804 		ret = storvsc_execute_vstor_op(device, request, false);
805 		if (ret != 0)
806 			return ret;
807 
808 		if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
809 			return -EINVAL;
810 
811 		if (vstor_packet->status == 0) {
812 			vmstor_proto_version =
813 				vmstor_protocols[i].protocol_version;
814 
815 			sense_buffer_size =
816 				vmstor_protocols[i].sense_buffer_size;
817 
818 			vmscsi_size_delta =
819 				vmstor_protocols[i].vmscsi_size_delta;
820 
821 			break;
822 		}
823 	}
824 
825 	if (vstor_packet->status != 0)
826 		return -EINVAL;
827 
828 
829 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
830 	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
831 	ret = storvsc_execute_vstor_op(device, request, true);
832 	if (ret != 0)
833 		return ret;
834 
835 	/*
836 	 * Check to see if multi-channel support is there.
837 	 * Hosts that implement protocol version of 5.1 and above
838 	 * support multi-channel.
839 	 */
840 	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
841 	if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
842 		if (vstor_packet->storage_channel_properties.flags &
843 		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
844 			process_sub_channels = true;
845 	}
846 	stor_device->max_transfer_bytes =
847 		vstor_packet->storage_channel_properties.max_transfer_bytes;
848 
849 	if (!is_fc)
850 		goto done;
851 
852 	/*
853 	 * For FC devices retrieve FC HBA data.
854 	 */
855 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
856 	vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
857 	ret = storvsc_execute_vstor_op(device, request, true);
858 	if (ret != 0)
859 		return ret;
860 
861 	/*
862 	 * Cache the currently active port and node ww names.
863 	 */
864 	cache_wwn(stor_device, vstor_packet);
865 
866 done:
867 
868 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
869 	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
870 	ret = storvsc_execute_vstor_op(device, request, true);
871 	if (ret != 0)
872 		return ret;
873 
874 	if (process_sub_channels)
875 		handle_multichannel_storage(device, max_chns);
876 
877 	return ret;
878 }
879 
880 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
881 				struct scsi_cmnd *scmnd,
882 				struct Scsi_Host *host,
883 				u8 asc, u8 ascq)
884 {
885 	struct storvsc_scan_work *wrk;
886 	void (*process_err_fn)(struct work_struct *work);
887 	bool do_work = false;
888 
889 	switch (SRB_STATUS(vm_srb->srb_status)) {
890 	case SRB_STATUS_ERROR:
891 		/*
892 		 * If there is an error; offline the device since all
893 		 * error recovery strategies would have already been
894 		 * deployed on the host side. However, if the command
895 		 * were a pass-through command deal with it appropriately.
896 		 */
897 		switch (scmnd->cmnd[0]) {
898 		case ATA_16:
899 		case ATA_12:
900 			set_host_byte(scmnd, DID_PASSTHROUGH);
901 			break;
902 		/*
903 		 * On Some Windows hosts TEST_UNIT_READY command can return
904 		 * SRB_STATUS_ERROR, let the upper level code deal with it
905 		 * based on the sense information.
906 		 */
907 		case TEST_UNIT_READY:
908 			break;
909 		default:
910 			set_host_byte(scmnd, DID_TARGET_FAILURE);
911 		}
912 		break;
913 	case SRB_STATUS_INVALID_LUN:
914 		do_work = true;
915 		process_err_fn = storvsc_remove_lun;
916 		break;
917 	case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
918 		if ((asc == 0x2a) && (ascq == 0x9)) {
919 			do_work = true;
920 			process_err_fn = storvsc_device_scan;
921 			/*
922 			 * Retry the I/O that trigerred this.
923 			 */
924 			set_host_byte(scmnd, DID_REQUEUE);
925 		}
926 		break;
927 	}
928 
929 	if (!do_work)
930 		return;
931 
932 	/*
933 	 * We need to schedule work to process this error; schedule it.
934 	 */
935 	wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
936 	if (!wrk) {
937 		set_host_byte(scmnd, DID_TARGET_FAILURE);
938 		return;
939 	}
940 
941 	wrk->host = host;
942 	wrk->lun = vm_srb->lun;
943 	INIT_WORK(&wrk->work, process_err_fn);
944 	schedule_work(&wrk->work);
945 }
946 
947 
948 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
949 				       struct storvsc_device *stor_dev)
950 {
951 	struct scsi_cmnd *scmnd = cmd_request->cmd;
952 	struct scsi_sense_hdr sense_hdr;
953 	struct vmscsi_request *vm_srb;
954 	struct Scsi_Host *host;
955 	u32 payload_sz = cmd_request->payload_sz;
956 	void *payload = cmd_request->payload;
957 
958 	host = stor_dev->host;
959 
960 	vm_srb = &cmd_request->vstor_packet.vm_srb;
961 
962 	scmnd->result = vm_srb->scsi_status;
963 
964 	if (scmnd->result) {
965 		if (scsi_normalize_sense(scmnd->sense_buffer,
966 				SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
967 		    do_logging(STORVSC_LOGGING_ERROR))
968 			scsi_print_sense_hdr(scmnd->device, "storvsc",
969 					     &sense_hdr);
970 	}
971 
972 	if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
973 		storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
974 					 sense_hdr.ascq);
975 
976 	scsi_set_resid(scmnd,
977 		cmd_request->payload->range.len -
978 		vm_srb->data_transfer_length);
979 
980 	scmnd->scsi_done(scmnd);
981 
982 	if (payload_sz >
983 		sizeof(struct vmbus_channel_packet_multipage_buffer))
984 		kfree(payload);
985 }
986 
987 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
988 				  struct vstor_packet *vstor_packet,
989 				  struct storvsc_cmd_request *request)
990 {
991 	struct vstor_packet *stor_pkt;
992 	struct hv_device *device = stor_device->device;
993 
994 	stor_pkt = &request->vstor_packet;
995 
996 	/*
997 	 * The current SCSI handling on the host side does
998 	 * not correctly handle:
999 	 * INQUIRY command with page code parameter set to 0x80
1000 	 * MODE_SENSE command with cmd[2] == 0x1c
1001 	 *
1002 	 * Setup srb and scsi status so this won't be fatal.
1003 	 * We do this so we can distinguish truly fatal failues
1004 	 * (srb status == 0x4) and off-line the device in that case.
1005 	 */
1006 
1007 	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1008 	   (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1009 		vstor_packet->vm_srb.scsi_status = 0;
1010 		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1011 	}
1012 
1013 
1014 	/* Copy over the status...etc */
1015 	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1016 	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1017 	stor_pkt->vm_srb.sense_info_length =
1018 	vstor_packet->vm_srb.sense_info_length;
1019 
1020 	if (vstor_packet->vm_srb.scsi_status != 0 ||
1021 	    vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1022 		storvsc_log(device, STORVSC_LOGGING_WARN,
1023 			"cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1024 			stor_pkt->vm_srb.cdb[0],
1025 			vstor_packet->vm_srb.scsi_status,
1026 			vstor_packet->vm_srb.srb_status);
1027 
1028 	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1029 		/* CHECK_CONDITION */
1030 		if (vstor_packet->vm_srb.srb_status &
1031 			SRB_STATUS_AUTOSENSE_VALID) {
1032 			/* autosense data available */
1033 
1034 			storvsc_log(device, STORVSC_LOGGING_WARN,
1035 				"stor pkt %p autosense data valid - len %d\n",
1036 				request, vstor_packet->vm_srb.sense_info_length);
1037 
1038 			memcpy(request->cmd->sense_buffer,
1039 			       vstor_packet->vm_srb.sense_data,
1040 			       vstor_packet->vm_srb.sense_info_length);
1041 
1042 		}
1043 	}
1044 
1045 	stor_pkt->vm_srb.data_transfer_length =
1046 	vstor_packet->vm_srb.data_transfer_length;
1047 
1048 	storvsc_command_completion(request, stor_device);
1049 
1050 	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1051 		stor_device->drain_notify)
1052 		wake_up(&stor_device->waiting_to_drain);
1053 
1054 
1055 }
1056 
1057 static void storvsc_on_receive(struct storvsc_device *stor_device,
1058 			     struct vstor_packet *vstor_packet,
1059 			     struct storvsc_cmd_request *request)
1060 {
1061 	struct storvsc_scan_work *work;
1062 
1063 	switch (vstor_packet->operation) {
1064 	case VSTOR_OPERATION_COMPLETE_IO:
1065 		storvsc_on_io_completion(stor_device, vstor_packet, request);
1066 		break;
1067 
1068 	case VSTOR_OPERATION_REMOVE_DEVICE:
1069 	case VSTOR_OPERATION_ENUMERATE_BUS:
1070 		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1071 		if (!work)
1072 			return;
1073 
1074 		INIT_WORK(&work->work, storvsc_host_scan);
1075 		work->host = stor_device->host;
1076 		schedule_work(&work->work);
1077 		break;
1078 
1079 	case VSTOR_OPERATION_FCHBA_DATA:
1080 		cache_wwn(stor_device, vstor_packet);
1081 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1082 		fc_host_node_name(stor_device->host) = stor_device->node_name;
1083 		fc_host_port_name(stor_device->host) = stor_device->port_name;
1084 #endif
1085 		break;
1086 	default:
1087 		break;
1088 	}
1089 }
1090 
1091 static void storvsc_on_channel_callback(void *context)
1092 {
1093 	struct vmbus_channel *channel = (struct vmbus_channel *)context;
1094 	struct hv_device *device;
1095 	struct storvsc_device *stor_device;
1096 	u32 bytes_recvd;
1097 	u64 request_id;
1098 	unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1099 	struct storvsc_cmd_request *request;
1100 	int ret;
1101 
1102 	if (channel->primary_channel != NULL)
1103 		device = channel->primary_channel->device_obj;
1104 	else
1105 		device = channel->device_obj;
1106 
1107 	stor_device = get_in_stor_device(device);
1108 	if (!stor_device)
1109 		return;
1110 
1111 	do {
1112 		ret = vmbus_recvpacket(channel, packet,
1113 				       ALIGN((sizeof(struct vstor_packet) -
1114 					     vmscsi_size_delta), 8),
1115 				       &bytes_recvd, &request_id);
1116 		if (ret == 0 && bytes_recvd > 0) {
1117 
1118 			request = (struct storvsc_cmd_request *)
1119 					(unsigned long)request_id;
1120 
1121 			if ((request == &stor_device->init_request) ||
1122 			    (request == &stor_device->reset_request)) {
1123 
1124 				memcpy(&request->vstor_packet, packet,
1125 				       (sizeof(struct vstor_packet) -
1126 					vmscsi_size_delta));
1127 				complete(&request->wait_event);
1128 			} else {
1129 				storvsc_on_receive(stor_device,
1130 						(struct vstor_packet *)packet,
1131 						request);
1132 			}
1133 		} else {
1134 			break;
1135 		}
1136 	} while (1);
1137 
1138 	return;
1139 }
1140 
1141 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1142 				  bool is_fc)
1143 {
1144 	struct vmstorage_channel_properties props;
1145 	int ret;
1146 
1147 	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1148 
1149 	ret = vmbus_open(device->channel,
1150 			 ring_size,
1151 			 ring_size,
1152 			 (void *)&props,
1153 			 sizeof(struct vmstorage_channel_properties),
1154 			 storvsc_on_channel_callback, device->channel);
1155 
1156 	if (ret != 0)
1157 		return ret;
1158 
1159 	ret = storvsc_channel_init(device, is_fc);
1160 
1161 	return ret;
1162 }
1163 
1164 static int storvsc_dev_remove(struct hv_device *device)
1165 {
1166 	struct storvsc_device *stor_device;
1167 	unsigned long flags;
1168 
1169 	stor_device = hv_get_drvdata(device);
1170 
1171 	spin_lock_irqsave(&device->channel->inbound_lock, flags);
1172 	stor_device->destroy = true;
1173 	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1174 
1175 	/*
1176 	 * At this point, all outbound traffic should be disable. We
1177 	 * only allow inbound traffic (responses) to proceed so that
1178 	 * outstanding requests can be completed.
1179 	 */
1180 
1181 	storvsc_wait_to_drain(stor_device);
1182 
1183 	/*
1184 	 * Since we have already drained, we don't need to busy wait
1185 	 * as was done in final_release_stor_device()
1186 	 * Note that we cannot set the ext pointer to NULL until
1187 	 * we have drained - to drain the outgoing packets, we need to
1188 	 * allow incoming packets.
1189 	 */
1190 	spin_lock_irqsave(&device->channel->inbound_lock, flags);
1191 	hv_set_drvdata(device, NULL);
1192 	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1193 
1194 	/* Close the channel */
1195 	vmbus_close(device->channel);
1196 
1197 	kfree(stor_device);
1198 	return 0;
1199 }
1200 
1201 static int storvsc_do_io(struct hv_device *device,
1202 			 struct storvsc_cmd_request *request)
1203 {
1204 	struct storvsc_device *stor_device;
1205 	struct vstor_packet *vstor_packet;
1206 	struct vmbus_channel *outgoing_channel;
1207 	int ret = 0;
1208 
1209 	vstor_packet = &request->vstor_packet;
1210 	stor_device = get_out_stor_device(device);
1211 
1212 	if (!stor_device)
1213 		return -ENODEV;
1214 
1215 
1216 	request->device  = device;
1217 	/*
1218 	 * Select an an appropriate channel to send the request out.
1219 	 */
1220 
1221 	outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1222 
1223 
1224 	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1225 
1226 	vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1227 					vmscsi_size_delta);
1228 
1229 
1230 	vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1231 
1232 
1233 	vstor_packet->vm_srb.data_transfer_length =
1234 	request->payload->range.len;
1235 
1236 	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1237 
1238 	if (request->payload->range.len) {
1239 
1240 		ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1241 				request->payload, request->payload_sz,
1242 				vstor_packet,
1243 				(sizeof(struct vstor_packet) -
1244 				vmscsi_size_delta),
1245 				(unsigned long)request);
1246 	} else {
1247 		ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1248 			       (sizeof(struct vstor_packet) -
1249 				vmscsi_size_delta),
1250 			       (unsigned long)request,
1251 			       VM_PKT_DATA_INBAND,
1252 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1253 	}
1254 
1255 	if (ret != 0)
1256 		return ret;
1257 
1258 	atomic_inc(&stor_device->num_outstanding_req);
1259 
1260 	return ret;
1261 }
1262 
1263 static int storvsc_device_configure(struct scsi_device *sdevice)
1264 {
1265 
1266 	blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1267 
1268 	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1269 
1270 	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1271 
1272 	/* Ensure there are no gaps in presented sgls */
1273 	blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1274 
1275 	sdevice->no_write_same = 1;
1276 
1277 	/*
1278 	 * Add blist flags to permit the reading of the VPD pages even when
1279 	 * the target may claim SPC-2 compliance. MSFT targets currently
1280 	 * claim SPC-2 compliance while they implement post SPC-2 features.
1281 	 * With this patch we can correctly handle WRITE_SAME_16 issues.
1282 	 */
1283 	sdevice->sdev_bflags |= msft_blist_flags;
1284 
1285 	/*
1286 	 * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1287 	 * if the device is a MSFT virtual device.  If the host is
1288 	 * WIN10 or newer, allow write_same.
1289 	 */
1290 	if (!strncmp(sdevice->vendor, "Msft", 4)) {
1291 		switch (vmstor_proto_version) {
1292 		case VMSTOR_PROTO_VERSION_WIN8:
1293 		case VMSTOR_PROTO_VERSION_WIN8_1:
1294 			sdevice->scsi_level = SCSI_SPC_3;
1295 			break;
1296 		}
1297 
1298 		if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1299 			sdevice->no_write_same = 0;
1300 	}
1301 
1302 	return 0;
1303 }
1304 
1305 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1306 			   sector_t capacity, int *info)
1307 {
1308 	sector_t nsect = capacity;
1309 	sector_t cylinders = nsect;
1310 	int heads, sectors_pt;
1311 
1312 	/*
1313 	 * We are making up these values; let us keep it simple.
1314 	 */
1315 	heads = 0xff;
1316 	sectors_pt = 0x3f;      /* Sectors per track */
1317 	sector_div(cylinders, heads * sectors_pt);
1318 	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1319 		cylinders = 0xffff;
1320 
1321 	info[0] = heads;
1322 	info[1] = sectors_pt;
1323 	info[2] = (int)cylinders;
1324 
1325 	return 0;
1326 }
1327 
1328 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1329 {
1330 	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1331 	struct hv_device *device = host_dev->dev;
1332 
1333 	struct storvsc_device *stor_device;
1334 	struct storvsc_cmd_request *request;
1335 	struct vstor_packet *vstor_packet;
1336 	int ret, t;
1337 
1338 
1339 	stor_device = get_out_stor_device(device);
1340 	if (!stor_device)
1341 		return FAILED;
1342 
1343 	request = &stor_device->reset_request;
1344 	vstor_packet = &request->vstor_packet;
1345 
1346 	init_completion(&request->wait_event);
1347 
1348 	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1349 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1350 	vstor_packet->vm_srb.path_id = stor_device->path_id;
1351 
1352 	ret = vmbus_sendpacket(device->channel, vstor_packet,
1353 			       (sizeof(struct vstor_packet) -
1354 				vmscsi_size_delta),
1355 			       (unsigned long)&stor_device->reset_request,
1356 			       VM_PKT_DATA_INBAND,
1357 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1358 	if (ret != 0)
1359 		return FAILED;
1360 
1361 	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1362 	if (t == 0)
1363 		return TIMEOUT_ERROR;
1364 
1365 
1366 	/*
1367 	 * At this point, all outstanding requests in the adapter
1368 	 * should have been flushed out and return to us
1369 	 * There is a potential race here where the host may be in
1370 	 * the process of responding when we return from here.
1371 	 * Just wait for all in-transit packets to be accounted for
1372 	 * before we return from here.
1373 	 */
1374 	storvsc_wait_to_drain(stor_device);
1375 
1376 	return SUCCESS;
1377 }
1378 
1379 /*
1380  * The host guarantees to respond to each command, although I/O latencies might
1381  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1382  * chance to perform EH.
1383  */
1384 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1385 {
1386 	return BLK_EH_RESET_TIMER;
1387 }
1388 
1389 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1390 {
1391 	bool allowed = true;
1392 	u8 scsi_op = scmnd->cmnd[0];
1393 
1394 	switch (scsi_op) {
1395 	/* the host does not handle WRITE_SAME, log accident usage */
1396 	case WRITE_SAME:
1397 	/*
1398 	 * smartd sends this command and the host does not handle
1399 	 * this. So, don't send it.
1400 	 */
1401 	case SET_WINDOW:
1402 		scmnd->result = ILLEGAL_REQUEST << 16;
1403 		allowed = false;
1404 		break;
1405 	default:
1406 		break;
1407 	}
1408 	return allowed;
1409 }
1410 
1411 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1412 {
1413 	int ret;
1414 	struct hv_host_device *host_dev = shost_priv(host);
1415 	struct hv_device *dev = host_dev->dev;
1416 	struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1417 	int i;
1418 	struct scatterlist *sgl;
1419 	unsigned int sg_count = 0;
1420 	struct vmscsi_request *vm_srb;
1421 	struct scatterlist *cur_sgl;
1422 	struct vmbus_packet_mpb_array  *payload;
1423 	u32 payload_sz;
1424 	u32 length;
1425 
1426 	if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1427 		/*
1428 		 * On legacy hosts filter unimplemented commands.
1429 		 * Future hosts are expected to correctly handle
1430 		 * unsupported commands. Furthermore, it is
1431 		 * possible that some of the currently
1432 		 * unsupported commands maybe supported in
1433 		 * future versions of the host.
1434 		 */
1435 		if (!storvsc_scsi_cmd_ok(scmnd)) {
1436 			scmnd->scsi_done(scmnd);
1437 			return 0;
1438 		}
1439 	}
1440 
1441 	/* Setup the cmd request */
1442 	cmd_request->cmd = scmnd;
1443 
1444 	vm_srb = &cmd_request->vstor_packet.vm_srb;
1445 	vm_srb->win8_extension.time_out_value = 60;
1446 
1447 	vm_srb->win8_extension.srb_flags |=
1448 		SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1449 
1450 	/* Build the SRB */
1451 	switch (scmnd->sc_data_direction) {
1452 	case DMA_TO_DEVICE:
1453 		vm_srb->data_in = WRITE_TYPE;
1454 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1455 		break;
1456 	case DMA_FROM_DEVICE:
1457 		vm_srb->data_in = READ_TYPE;
1458 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1459 		break;
1460 	case DMA_NONE:
1461 		vm_srb->data_in = UNKNOWN_TYPE;
1462 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1463 		break;
1464 	default:
1465 		/*
1466 		 * This is DMA_BIDIRECTIONAL or something else we are never
1467 		 * supposed to see here.
1468 		 */
1469 		WARN(1, "Unexpected data direction: %d\n",
1470 		     scmnd->sc_data_direction);
1471 		return -EINVAL;
1472 	}
1473 
1474 
1475 	vm_srb->port_number = host_dev->port;
1476 	vm_srb->path_id = scmnd->device->channel;
1477 	vm_srb->target_id = scmnd->device->id;
1478 	vm_srb->lun = scmnd->device->lun;
1479 
1480 	vm_srb->cdb_length = scmnd->cmd_len;
1481 
1482 	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1483 
1484 	sgl = (struct scatterlist *)scsi_sglist(scmnd);
1485 	sg_count = scsi_sg_count(scmnd);
1486 
1487 	length = scsi_bufflen(scmnd);
1488 	payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1489 	payload_sz = sizeof(cmd_request->mpb);
1490 
1491 	if (sg_count) {
1492 		if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1493 
1494 			payload_sz = (sg_count * sizeof(void *) +
1495 				      sizeof(struct vmbus_packet_mpb_array));
1496 			payload = kmalloc(payload_sz, GFP_ATOMIC);
1497 			if (!payload)
1498 				return SCSI_MLQUEUE_DEVICE_BUSY;
1499 		}
1500 
1501 		payload->range.len = length;
1502 		payload->range.offset = sgl[0].offset;
1503 
1504 		cur_sgl = sgl;
1505 		for (i = 0; i < sg_count; i++) {
1506 			payload->range.pfn_array[i] =
1507 				page_to_pfn(sg_page((cur_sgl)));
1508 			cur_sgl = sg_next(cur_sgl);
1509 		}
1510 
1511 	} else if (scsi_sglist(scmnd)) {
1512 		payload->range.len = length;
1513 		payload->range.offset =
1514 			virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1515 		payload->range.pfn_array[0] =
1516 			virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1517 	}
1518 
1519 	cmd_request->payload = payload;
1520 	cmd_request->payload_sz = payload_sz;
1521 
1522 	/* Invokes the vsc to start an IO */
1523 	ret = storvsc_do_io(dev, cmd_request);
1524 
1525 	if (ret == -EAGAIN) {
1526 		/* no more space */
1527 		return SCSI_MLQUEUE_DEVICE_BUSY;
1528 	}
1529 
1530 	return 0;
1531 }
1532 
1533 static struct scsi_host_template scsi_driver = {
1534 	.module	=		THIS_MODULE,
1535 	.name =			"storvsc_host_t",
1536 	.cmd_size =             sizeof(struct storvsc_cmd_request),
1537 	.bios_param =		storvsc_get_chs,
1538 	.queuecommand =		storvsc_queuecommand,
1539 	.eh_host_reset_handler =	storvsc_host_reset_handler,
1540 	.proc_name =		"storvsc_host",
1541 	.eh_timed_out =		storvsc_eh_timed_out,
1542 	.slave_configure =	storvsc_device_configure,
1543 	.cmd_per_lun =		255,
1544 	.this_id =		-1,
1545 	.use_clustering =	ENABLE_CLUSTERING,
1546 	/* Make sure we dont get a sg segment crosses a page boundary */
1547 	.dma_boundary =		PAGE_SIZE-1,
1548 	.no_write_same =	1,
1549 };
1550 
1551 enum {
1552 	SCSI_GUID,
1553 	IDE_GUID,
1554 	SFC_GUID,
1555 };
1556 
1557 static const struct hv_vmbus_device_id id_table[] = {
1558 	/* SCSI guid */
1559 	{ HV_SCSI_GUID,
1560 	  .driver_data = SCSI_GUID
1561 	},
1562 	/* IDE guid */
1563 	{ HV_IDE_GUID,
1564 	  .driver_data = IDE_GUID
1565 	},
1566 	/* Fibre Channel GUID */
1567 	{
1568 	  HV_SYNTHFC_GUID,
1569 	  .driver_data = SFC_GUID
1570 	},
1571 	{ },
1572 };
1573 
1574 MODULE_DEVICE_TABLE(vmbus, id_table);
1575 
1576 static int storvsc_probe(struct hv_device *device,
1577 			const struct hv_vmbus_device_id *dev_id)
1578 {
1579 	int ret;
1580 	int num_cpus = num_online_cpus();
1581 	struct Scsi_Host *host;
1582 	struct hv_host_device *host_dev;
1583 	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1584 	bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1585 	int target = 0;
1586 	struct storvsc_device *stor_device;
1587 	int max_luns_per_target;
1588 	int max_targets;
1589 	int max_channels;
1590 	int max_sub_channels = 0;
1591 
1592 	/*
1593 	 * Based on the windows host we are running on,
1594 	 * set state to properly communicate with the host.
1595 	 */
1596 
1597 	if (vmbus_proto_version < VERSION_WIN8) {
1598 		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1599 		max_targets = STORVSC_IDE_MAX_TARGETS;
1600 		max_channels = STORVSC_IDE_MAX_CHANNELS;
1601 	} else {
1602 		max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1603 		max_targets = STORVSC_MAX_TARGETS;
1604 		max_channels = STORVSC_MAX_CHANNELS;
1605 		/*
1606 		 * On Windows8 and above, we support sub-channels for storage.
1607 		 * The number of sub-channels offerred is based on the number of
1608 		 * VCPUs in the guest.
1609 		 */
1610 		max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1611 	}
1612 
1613 	scsi_driver.can_queue = (max_outstanding_req_per_channel *
1614 				 (max_sub_channels + 1));
1615 
1616 	host = scsi_host_alloc(&scsi_driver,
1617 			       sizeof(struct hv_host_device));
1618 	if (!host)
1619 		return -ENOMEM;
1620 
1621 	host_dev = shost_priv(host);
1622 	memset(host_dev, 0, sizeof(struct hv_host_device));
1623 
1624 	host_dev->port = host->host_no;
1625 	host_dev->dev = device;
1626 
1627 
1628 	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1629 	if (!stor_device) {
1630 		ret = -ENOMEM;
1631 		goto err_out0;
1632 	}
1633 
1634 	stor_device->destroy = false;
1635 	stor_device->open_sub_channel = false;
1636 	init_waitqueue_head(&stor_device->waiting_to_drain);
1637 	stor_device->device = device;
1638 	stor_device->host = host;
1639 	hv_set_drvdata(device, stor_device);
1640 
1641 	stor_device->port_number = host->host_no;
1642 	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1643 	if (ret)
1644 		goto err_out1;
1645 
1646 	host_dev->path = stor_device->path_id;
1647 	host_dev->target = stor_device->target_id;
1648 
1649 	switch (dev_id->driver_data) {
1650 	case SFC_GUID:
1651 		host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1652 		host->max_id = STORVSC_FC_MAX_TARGETS;
1653 		host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1654 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1655 		host->transportt = fc_transport_template;
1656 #endif
1657 		break;
1658 
1659 	case SCSI_GUID:
1660 		host->max_lun = max_luns_per_target;
1661 		host->max_id = max_targets;
1662 		host->max_channel = max_channels - 1;
1663 		break;
1664 
1665 	default:
1666 		host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1667 		host->max_id = STORVSC_IDE_MAX_TARGETS;
1668 		host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1669 		break;
1670 	}
1671 	/* max cmd length */
1672 	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1673 
1674 	/*
1675 	 * set the table size based on the info we got
1676 	 * from the host.
1677 	 */
1678 	host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1679 
1680 	/* Register the HBA and start the scsi bus scan */
1681 	ret = scsi_add_host(host, &device->device);
1682 	if (ret != 0)
1683 		goto err_out2;
1684 
1685 	if (!dev_is_ide) {
1686 		scsi_scan_host(host);
1687 	} else {
1688 		target = (device->dev_instance.b[5] << 8 |
1689 			 device->dev_instance.b[4]);
1690 		ret = scsi_add_device(host, 0, target, 0);
1691 		if (ret) {
1692 			scsi_remove_host(host);
1693 			goto err_out2;
1694 		}
1695 	}
1696 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1697 	if (host->transportt == fc_transport_template) {
1698 		fc_host_node_name(host) = stor_device->node_name;
1699 		fc_host_port_name(host) = stor_device->port_name;
1700 	}
1701 #endif
1702 	return 0;
1703 
1704 err_out2:
1705 	/*
1706 	 * Once we have connected with the host, we would need to
1707 	 * to invoke storvsc_dev_remove() to rollback this state and
1708 	 * this call also frees up the stor_device; hence the jump around
1709 	 * err_out1 label.
1710 	 */
1711 	storvsc_dev_remove(device);
1712 	goto err_out0;
1713 
1714 err_out1:
1715 	kfree(stor_device);
1716 
1717 err_out0:
1718 	scsi_host_put(host);
1719 	return ret;
1720 }
1721 
1722 static int storvsc_remove(struct hv_device *dev)
1723 {
1724 	struct storvsc_device *stor_device = hv_get_drvdata(dev);
1725 	struct Scsi_Host *host = stor_device->host;
1726 
1727 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1728 	if (host->transportt == fc_transport_template)
1729 		fc_remove_host(host);
1730 #endif
1731 	scsi_remove_host(host);
1732 	storvsc_dev_remove(dev);
1733 	scsi_host_put(host);
1734 
1735 	return 0;
1736 }
1737 
1738 static struct hv_driver storvsc_drv = {
1739 	.name = KBUILD_MODNAME,
1740 	.id_table = id_table,
1741 	.probe = storvsc_probe,
1742 	.remove = storvsc_remove,
1743 };
1744 
1745 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1746 static struct fc_function_template fc_transport_functions = {
1747 	.show_host_node_name = 1,
1748 	.show_host_port_name = 1,
1749 };
1750 #endif
1751 
1752 static int __init storvsc_drv_init(void)
1753 {
1754 	int ret;
1755 
1756 	/*
1757 	 * Divide the ring buffer data size (which is 1 page less
1758 	 * than the ring buffer size since that page is reserved for
1759 	 * the ring buffer indices) by the max request size (which is
1760 	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1761 	 */
1762 	max_outstanding_req_per_channel =
1763 		((storvsc_ringbuffer_size - PAGE_SIZE) /
1764 		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1765 		sizeof(struct vstor_packet) + sizeof(u64) -
1766 		vmscsi_size_delta,
1767 		sizeof(u64)));
1768 
1769 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1770 	fc_transport_template = fc_attach_transport(&fc_transport_functions);
1771 	if (!fc_transport_template)
1772 		return -ENODEV;
1773 #endif
1774 
1775 	ret = vmbus_driver_register(&storvsc_drv);
1776 
1777 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1778 	if (ret)
1779 		fc_release_transport(fc_transport_template);
1780 #endif
1781 
1782 	return ret;
1783 }
1784 
1785 static void __exit storvsc_drv_exit(void)
1786 {
1787 	vmbus_driver_unregister(&storvsc_drv);
1788 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1789 	fc_release_transport(fc_transport_template);
1790 #endif
1791 }
1792 
1793 MODULE_LICENSE("GPL");
1794 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1795 module_init(storvsc_drv_init);
1796 module_exit(storvsc_drv_exit);
1797