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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 #include <scsi/scsi_transport.h>
46 
47 /*
48  * All wire protocol details (storage protocol between the guest and the host)
49  * are consolidated here.
50  *
51  * Begin protocol definitions.
52  */
53 
54 /*
55  * Version history:
56  * V1 Beta: 0.1
57  * V1 RC < 2008/1/31: 1.0
58  * V1 RC > 2008/1/31:  2.0
59  * Win7: 4.2
60  * Win8: 5.1
61  * Win8.1: 6.0
62  * Win10: 6.2
63  */
64 
65 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)	((((MAJOR_) & 0xff) << 8) | \
66 						(((MINOR_) & 0xff)))
67 
68 #define VMSTOR_PROTO_VERSION_WIN6	VMSTOR_PROTO_VERSION(2, 0)
69 #define VMSTOR_PROTO_VERSION_WIN7	VMSTOR_PROTO_VERSION(4, 2)
70 #define VMSTOR_PROTO_VERSION_WIN8	VMSTOR_PROTO_VERSION(5, 1)
71 #define VMSTOR_PROTO_VERSION_WIN8_1	VMSTOR_PROTO_VERSION(6, 0)
72 #define VMSTOR_PROTO_VERSION_WIN10	VMSTOR_PROTO_VERSION(6, 2)
73 
74 /*  Packet structure describing virtual storage requests. */
75 enum vstor_packet_operation {
76 	VSTOR_OPERATION_COMPLETE_IO		= 1,
77 	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
78 	VSTOR_OPERATION_EXECUTE_SRB		= 3,
79 	VSTOR_OPERATION_RESET_LUN		= 4,
80 	VSTOR_OPERATION_RESET_ADAPTER		= 5,
81 	VSTOR_OPERATION_RESET_BUS		= 6,
82 	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
83 	VSTOR_OPERATION_END_INITIALIZATION	= 8,
84 	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
85 	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
86 	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
87 	VSTOR_OPERATION_FCHBA_DATA              = 12,
88 	VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
89 	VSTOR_OPERATION_MAXIMUM                 = 13
90 };
91 
92 /*
93  * WWN packet for Fibre Channel HBA
94  */
95 
96 struct hv_fc_wwn_packet {
97 	u8	primary_active;
98 	u8	reserved1[3];
99 	u8	primary_port_wwn[8];
100 	u8	primary_node_wwn[8];
101 	u8	secondary_port_wwn[8];
102 	u8	secondary_node_wwn[8];
103 };
104 
105 
106 
107 /*
108  * SRB Flag Bits
109  */
110 
111 #define SRB_FLAGS_QUEUE_ACTION_ENABLE		0x00000002
112 #define SRB_FLAGS_DISABLE_DISCONNECT		0x00000004
113 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER	0x00000008
114 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE		0x00000010
115 #define SRB_FLAGS_DISABLE_AUTOSENSE		0x00000020
116 #define SRB_FLAGS_DATA_IN			0x00000040
117 #define SRB_FLAGS_DATA_OUT			0x00000080
118 #define SRB_FLAGS_NO_DATA_TRANSFER		0x00000000
119 #define SRB_FLAGS_UNSPECIFIED_DIRECTION	(SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
120 #define SRB_FLAGS_NO_QUEUE_FREEZE		0x00000100
121 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE		0x00000200
122 #define SRB_FLAGS_FREE_SENSE_BUFFER		0x00000400
123 
124 /*
125  * This flag indicates the request is part of the workflow for processing a D3.
126  */
127 #define SRB_FLAGS_D3_PROCESSING			0x00000800
128 #define SRB_FLAGS_IS_ACTIVE			0x00010000
129 #define SRB_FLAGS_ALLOCATED_FROM_ZONE		0x00020000
130 #define SRB_FLAGS_SGLIST_FROM_POOL		0x00040000
131 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE		0x00080000
132 #define SRB_FLAGS_NO_KEEP_AWAKE			0x00100000
133 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE	0x00200000
134 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT	0x00400000
135 #define SRB_FLAGS_DONT_START_NEXT_PACKET	0x00800000
136 #define SRB_FLAGS_PORT_DRIVER_RESERVED		0x0F000000
137 #define SRB_FLAGS_CLASS_DRIVER_RESERVED		0xF0000000
138 
139 #define SP_UNTAGGED			((unsigned char) ~0)
140 #define SRB_SIMPLE_TAG_REQUEST		0x20
141 
142 /*
143  * Platform neutral description of a scsi request -
144  * this remains the same across the write regardless of 32/64 bit
145  * note: it's patterned off the SCSI_PASS_THROUGH structure
146  */
147 #define STORVSC_MAX_CMD_LEN			0x10
148 
149 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE	0x14
150 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE	0x12
151 
152 #define STORVSC_SENSE_BUFFER_SIZE		0x14
153 #define STORVSC_MAX_BUF_LEN_WITH_PADDING	0x14
154 
155 /*
156  * Sense buffer size changed in win8; have a run-time
157  * variable to track the size we should use.  This value will
158  * likely change during protocol negotiation but it is valid
159  * to start by assuming pre-Win8.
160  */
161 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
162 
163 /*
164  * The storage protocol version is determined during the
165  * initial exchange with the host.  It will indicate which
166  * storage functionality is available in the host.
167 */
168 static int vmstor_proto_version;
169 
170 #define STORVSC_LOGGING_NONE	0
171 #define STORVSC_LOGGING_ERROR	1
172 #define STORVSC_LOGGING_WARN	2
173 
174 static int logging_level = STORVSC_LOGGING_ERROR;
175 module_param(logging_level, int, S_IRUGO|S_IWUSR);
176 MODULE_PARM_DESC(logging_level,
177 	"Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
178 
do_logging(int level)179 static inline bool do_logging(int level)
180 {
181 	return logging_level >= level;
182 }
183 
184 #define storvsc_log(dev, level, fmt, ...)			\
185 do {								\
186 	if (do_logging(level))					\
187 		dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);	\
188 } while (0)
189 
190 struct vmscsi_win8_extension {
191 	/*
192 	 * The following were added in Windows 8
193 	 */
194 	u16 reserve;
195 	u8  queue_tag;
196 	u8  queue_action;
197 	u32 srb_flags;
198 	u32 time_out_value;
199 	u32 queue_sort_ey;
200 } __packed;
201 
202 struct vmscsi_request {
203 	u16 length;
204 	u8 srb_status;
205 	u8 scsi_status;
206 
207 	u8  port_number;
208 	u8  path_id;
209 	u8  target_id;
210 	u8  lun;
211 
212 	u8  cdb_length;
213 	u8  sense_info_length;
214 	u8  data_in;
215 	u8  reserved;
216 
217 	u32 data_transfer_length;
218 
219 	union {
220 		u8 cdb[STORVSC_MAX_CMD_LEN];
221 		u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
222 		u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
223 	};
224 	/*
225 	 * The following was added in win8.
226 	 */
227 	struct vmscsi_win8_extension win8_extension;
228 
229 } __attribute((packed));
230 
231 
232 /*
233  * The size of the vmscsi_request has changed in win8. The
234  * additional size is because of new elements added to the
235  * structure. These elements are valid only when we are talking
236  * to a win8 host.
237  * Track the correction to size we need to apply. This value
238  * will likely change during protocol negotiation but it is
239  * valid to start by assuming pre-Win8.
240  */
241 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
242 
243 /*
244  * The list of storage protocols in order of preference.
245  */
246 struct vmstor_protocol {
247 	int protocol_version;
248 	int sense_buffer_size;
249 	int vmscsi_size_delta;
250 };
251 
252 
253 static const struct vmstor_protocol vmstor_protocols[] = {
254 	{
255 		VMSTOR_PROTO_VERSION_WIN10,
256 		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
257 		0
258 	},
259 	{
260 		VMSTOR_PROTO_VERSION_WIN8_1,
261 		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
262 		0
263 	},
264 	{
265 		VMSTOR_PROTO_VERSION_WIN8,
266 		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
267 		0
268 	},
269 	{
270 		VMSTOR_PROTO_VERSION_WIN7,
271 		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
272 		sizeof(struct vmscsi_win8_extension),
273 	},
274 	{
275 		VMSTOR_PROTO_VERSION_WIN6,
276 		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
277 		sizeof(struct vmscsi_win8_extension),
278 	}
279 };
280 
281 
282 /*
283  * This structure is sent during the initialization phase to get the different
284  * properties of the channel.
285  */
286 
287 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL		0x1
288 
289 struct vmstorage_channel_properties {
290 	u32 reserved;
291 	u16 max_channel_cnt;
292 	u16 reserved1;
293 
294 	u32 flags;
295 	u32   max_transfer_bytes;
296 
297 	u64  reserved2;
298 } __packed;
299 
300 /*  This structure is sent during the storage protocol negotiations. */
301 struct vmstorage_protocol_version {
302 	/* Major (MSW) and minor (LSW) version numbers. */
303 	u16 major_minor;
304 
305 	/*
306 	 * Revision number is auto-incremented whenever this file is changed
307 	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
308 	 * definitely indicate incompatibility--but it does indicate mismatched
309 	 * builds.
310 	 * This is only used on the windows side. Just set it to 0.
311 	 */
312 	u16 revision;
313 } __packed;
314 
315 /* Channel Property Flags */
316 #define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
317 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
318 
319 struct vstor_packet {
320 	/* Requested operation type */
321 	enum vstor_packet_operation operation;
322 
323 	/*  Flags - see below for values */
324 	u32 flags;
325 
326 	/* Status of the request returned from the server side. */
327 	u32 status;
328 
329 	/* Data payload area */
330 	union {
331 		/*
332 		 * Structure used to forward SCSI commands from the
333 		 * client to the server.
334 		 */
335 		struct vmscsi_request vm_srb;
336 
337 		/* Structure used to query channel properties. */
338 		struct vmstorage_channel_properties storage_channel_properties;
339 
340 		/* Used during version negotiations. */
341 		struct vmstorage_protocol_version version;
342 
343 		/* Fibre channel address packet */
344 		struct hv_fc_wwn_packet wwn_packet;
345 
346 		/* Number of sub-channels to create */
347 		u16 sub_channel_count;
348 
349 		/* This will be the maximum of the union members */
350 		u8  buffer[0x34];
351 	};
352 } __packed;
353 
354 /*
355  * Packet Flags:
356  *
357  * This flag indicates that the server should send back a completion for this
358  * packet.
359  */
360 
361 #define REQUEST_COMPLETION_FLAG	0x1
362 
363 /* Matches Windows-end */
364 enum storvsc_request_type {
365 	WRITE_TYPE = 0,
366 	READ_TYPE,
367 	UNKNOWN_TYPE,
368 };
369 
370 /*
371  * SRB status codes and masks; a subset of the codes used here.
372  */
373 
374 #define SRB_STATUS_AUTOSENSE_VALID	0x80
375 #define SRB_STATUS_QUEUE_FROZEN		0x40
376 #define SRB_STATUS_INVALID_LUN	0x20
377 #define SRB_STATUS_SUCCESS	0x01
378 #define SRB_STATUS_ABORTED	0x02
379 #define SRB_STATUS_ERROR	0x04
380 #define SRB_STATUS_DATA_OVERRUN	0x12
381 
382 #define SRB_STATUS(status) \
383 	(status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
384 /*
385  * This is the end of Protocol specific defines.
386  */
387 
388 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
389 static u32 max_outstanding_req_per_channel;
390 
391 static int storvsc_vcpus_per_sub_channel = 4;
392 
393 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
394 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
395 
396 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
397 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
398 /*
399  * Timeout in seconds for all devices managed by this driver.
400  */
401 static int storvsc_timeout = 180;
402 
403 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
404 static struct scsi_transport_template *fc_transport_template;
405 #endif
406 
407 static 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 
421 struct 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 */
438 struct storvsc_device {
439 	struct hv_device *device;
440 
441 	bool	 destroy;
442 	bool	 drain_notify;
443 	bool	 open_sub_channel;
444 	atomic_t num_outstanding_req;
445 	struct Scsi_Host *host;
446 
447 	wait_queue_head_t waiting_to_drain;
448 
449 	/*
450 	 * Each unique Port/Path/Target represents 1 channel ie scsi
451 	 * controller. In reality, the pathid, targetid is always 0
452 	 * and the port is set by us
453 	 */
454 	unsigned int port_number;
455 	unsigned char path_id;
456 	unsigned char target_id;
457 
458 	/*
459 	 * Max I/O, the device can support.
460 	 */
461 	u32   max_transfer_bytes;
462 	/*
463 	 * Number of sub-channels we will open.
464 	 */
465 	u16 num_sc;
466 	struct vmbus_channel **stor_chns;
467 	/*
468 	 * Mask of CPUs bound to subchannels.
469 	 */
470 	struct cpumask alloced_cpus;
471 	/* Used for vsc/vsp channel reset process */
472 	struct storvsc_cmd_request init_request;
473 	struct storvsc_cmd_request reset_request;
474 	/*
475 	 * Currently active port and node names for FC devices.
476 	 */
477 	u64 node_name;
478 	u64 port_name;
479 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
480 	struct fc_rport *rport;
481 #endif
482 };
483 
484 struct hv_host_device {
485 	struct hv_device *dev;
486 	unsigned int port;
487 	unsigned char path;
488 	unsigned char target;
489 };
490 
491 struct storvsc_scan_work {
492 	struct work_struct work;
493 	struct Scsi_Host *host;
494 	u8 lun;
495 	u8 tgt_id;
496 };
497 
storvsc_device_scan(struct work_struct * work)498 static void storvsc_device_scan(struct work_struct *work)
499 {
500 	struct storvsc_scan_work *wrk;
501 	struct scsi_device *sdev;
502 
503 	wrk = container_of(work, struct storvsc_scan_work, work);
504 
505 	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
506 	if (!sdev)
507 		goto done;
508 	scsi_rescan_device(&sdev->sdev_gendev);
509 	scsi_device_put(sdev);
510 
511 done:
512 	kfree(wrk);
513 }
514 
storvsc_host_scan(struct work_struct * work)515 static void storvsc_host_scan(struct work_struct *work)
516 {
517 	struct storvsc_scan_work *wrk;
518 	struct Scsi_Host *host;
519 	struct scsi_device *sdev;
520 
521 	wrk = container_of(work, struct storvsc_scan_work, work);
522 	host = wrk->host;
523 
524 	/*
525 	 * Before scanning the host, first check to see if any of the
526 	 * currrently known devices have been hot removed. We issue a
527 	 * "unit ready" command against all currently known devices.
528 	 * This I/O will result in an error for devices that have been
529 	 * removed. As part of handling the I/O error, we remove the device.
530 	 *
531 	 * When a LUN is added or removed, the host sends us a signal to
532 	 * scan the host. Thus we are forced to discover the LUNs that
533 	 * may have been removed this way.
534 	 */
535 	mutex_lock(&host->scan_mutex);
536 	shost_for_each_device(sdev, host)
537 		scsi_test_unit_ready(sdev, 1, 1, NULL);
538 	mutex_unlock(&host->scan_mutex);
539 	/*
540 	 * Now scan the host to discover LUNs that may have been added.
541 	 */
542 	scsi_scan_host(host);
543 
544 	kfree(wrk);
545 }
546 
storvsc_remove_lun(struct work_struct * work)547 static void storvsc_remove_lun(struct work_struct *work)
548 {
549 	struct storvsc_scan_work *wrk;
550 	struct scsi_device *sdev;
551 
552 	wrk = container_of(work, struct storvsc_scan_work, work);
553 	if (!scsi_host_get(wrk->host))
554 		goto done;
555 
556 	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
557 
558 	if (sdev) {
559 		scsi_remove_device(sdev);
560 		scsi_device_put(sdev);
561 	}
562 	scsi_host_put(wrk->host);
563 
564 done:
565 	kfree(wrk);
566 }
567 
568 
569 /*
570  * We can get incoming messages from the host that are not in response to
571  * messages that we have sent out. An example of this would be messages
572  * received by the guest to notify dynamic addition/removal of LUNs. To
573  * deal with potential race conditions where the driver may be in the
574  * midst of being unloaded when we might receive an unsolicited message
575  * from the host, we have implemented a mechanism to gurantee sequential
576  * consistency:
577  *
578  * 1) Once the device is marked as being destroyed, we will fail all
579  *    outgoing messages.
580  * 2) We permit incoming messages when the device is being destroyed,
581  *    only to properly account for messages already sent out.
582  */
583 
get_out_stor_device(struct hv_device * device)584 static inline struct storvsc_device *get_out_stor_device(
585 					struct hv_device *device)
586 {
587 	struct storvsc_device *stor_device;
588 
589 	stor_device = hv_get_drvdata(device);
590 
591 	if (stor_device && stor_device->destroy)
592 		stor_device = NULL;
593 
594 	return stor_device;
595 }
596 
597 
storvsc_wait_to_drain(struct storvsc_device * dev)598 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
599 {
600 	dev->drain_notify = true;
601 	wait_event(dev->waiting_to_drain,
602 		   atomic_read(&dev->num_outstanding_req) == 0);
603 	dev->drain_notify = false;
604 }
605 
get_in_stor_device(struct hv_device * device)606 static inline struct storvsc_device *get_in_stor_device(
607 					struct hv_device *device)
608 {
609 	struct storvsc_device *stor_device;
610 
611 	stor_device = hv_get_drvdata(device);
612 
613 	if (!stor_device)
614 		goto get_in_err;
615 
616 	/*
617 	 * If the device is being destroyed; allow incoming
618 	 * traffic only to cleanup outstanding requests.
619 	 */
620 
621 	if (stor_device->destroy  &&
622 		(atomic_read(&stor_device->num_outstanding_req) == 0))
623 		stor_device = NULL;
624 
625 get_in_err:
626 	return stor_device;
627 
628 }
629 
handle_sc_creation(struct vmbus_channel * new_sc)630 static void handle_sc_creation(struct vmbus_channel *new_sc)
631 {
632 	struct hv_device *device = new_sc->primary_channel->device_obj;
633 	struct storvsc_device *stor_device;
634 	struct vmstorage_channel_properties props;
635 
636 	stor_device = get_out_stor_device(device);
637 	if (!stor_device)
638 		return;
639 
640 	if (stor_device->open_sub_channel == false)
641 		return;
642 
643 	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
644 
645 	vmbus_open(new_sc,
646 		   storvsc_ringbuffer_size,
647 		   storvsc_ringbuffer_size,
648 		   (void *)&props,
649 		   sizeof(struct vmstorage_channel_properties),
650 		   storvsc_on_channel_callback, new_sc);
651 
652 	if (new_sc->state == CHANNEL_OPENED_STATE) {
653 		stor_device->stor_chns[new_sc->target_cpu] = new_sc;
654 		cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
655 	}
656 }
657 
handle_multichannel_storage(struct hv_device * device,int max_chns)658 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
659 {
660 	struct storvsc_device *stor_device;
661 	int num_sc;
662 	struct storvsc_cmd_request *request;
663 	struct vstor_packet *vstor_packet;
664 	int ret, t;
665 
666 	/*
667 	 * If the number of CPUs is artificially restricted, such as
668 	 * with maxcpus=1 on the kernel boot line, Hyper-V could offer
669 	 * sub-channels >= the number of CPUs. These sub-channels
670 	 * should not be created. The primary channel is already created
671 	 * and assigned to one CPU, so check against # CPUs - 1.
672 	 */
673 	num_sc = min((int)(num_online_cpus() - 1), max_chns);
674 	if (!num_sc)
675 		return;
676 
677 	stor_device = get_out_stor_device(device);
678 	if (!stor_device)
679 		return;
680 
681 	stor_device->num_sc = num_sc;
682 	request = &stor_device->init_request;
683 	vstor_packet = &request->vstor_packet;
684 
685 	stor_device->open_sub_channel = true;
686 	/*
687 	 * Establish a handler for dealing with subchannels.
688 	 */
689 	vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
690 
691 	/*
692 	 * Check to see if sub-channels have already been created. This
693 	 * can happen when this driver is re-loaded after unloading.
694 	 */
695 
696 	if (vmbus_are_subchannels_present(device->channel))
697 		return;
698 
699 	stor_device->open_sub_channel = false;
700 	/*
701 	 * Request the host to create sub-channels.
702 	 */
703 	memset(request, 0, sizeof(struct storvsc_cmd_request));
704 	init_completion(&request->wait_event);
705 	vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
706 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
707 	vstor_packet->sub_channel_count = num_sc;
708 
709 	ret = vmbus_sendpacket(device->channel, vstor_packet,
710 			       (sizeof(struct vstor_packet) -
711 			       vmscsi_size_delta),
712 			       (unsigned long)request,
713 			       VM_PKT_DATA_INBAND,
714 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
715 
716 	if (ret != 0)
717 		return;
718 
719 	t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
720 	if (t == 0)
721 		return;
722 
723 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
724 	    vstor_packet->status != 0)
725 		return;
726 
727 	/*
728 	 * Now that we created the sub-channels, invoke the check; this
729 	 * may trigger the callback.
730 	 */
731 	stor_device->open_sub_channel = true;
732 	vmbus_are_subchannels_present(device->channel);
733 }
734 
cache_wwn(struct storvsc_device * stor_device,struct vstor_packet * vstor_packet)735 static void cache_wwn(struct storvsc_device *stor_device,
736 		      struct vstor_packet *vstor_packet)
737 {
738 	/*
739 	 * Cache the currently active port and node ww names.
740 	 */
741 	if (vstor_packet->wwn_packet.primary_active) {
742 		stor_device->node_name =
743 			wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
744 		stor_device->port_name =
745 			wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
746 	} else {
747 		stor_device->node_name =
748 			wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
749 		stor_device->port_name =
750 			wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
751 	}
752 }
753 
754 
storvsc_execute_vstor_op(struct hv_device * device,struct storvsc_cmd_request * request,bool status_check)755 static int storvsc_execute_vstor_op(struct hv_device *device,
756 				    struct storvsc_cmd_request *request,
757 				    bool status_check)
758 {
759 	struct vstor_packet *vstor_packet;
760 	int ret, t;
761 
762 	vstor_packet = &request->vstor_packet;
763 
764 	init_completion(&request->wait_event);
765 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
766 
767 	ret = vmbus_sendpacket(device->channel, vstor_packet,
768 			       (sizeof(struct vstor_packet) -
769 			       vmscsi_size_delta),
770 			       (unsigned long)request,
771 			       VM_PKT_DATA_INBAND,
772 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
773 	if (ret != 0)
774 		return ret;
775 
776 	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
777 	if (t == 0)
778 		return -ETIMEDOUT;
779 
780 	if (!status_check)
781 		return ret;
782 
783 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
784 	    vstor_packet->status != 0)
785 		return -EINVAL;
786 
787 	return ret;
788 }
789 
storvsc_channel_init(struct hv_device * device,bool is_fc)790 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
791 {
792 	struct storvsc_device *stor_device;
793 	struct storvsc_cmd_request *request;
794 	struct vstor_packet *vstor_packet;
795 	int ret, i;
796 	int max_chns;
797 	bool process_sub_channels = false;
798 
799 	stor_device = get_out_stor_device(device);
800 	if (!stor_device)
801 		return -ENODEV;
802 
803 	request = &stor_device->init_request;
804 	vstor_packet = &request->vstor_packet;
805 
806 	/*
807 	 * Now, initiate the vsc/vsp initialization protocol on the open
808 	 * channel
809 	 */
810 	memset(request, 0, sizeof(struct storvsc_cmd_request));
811 	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
812 	ret = storvsc_execute_vstor_op(device, request, true);
813 	if (ret)
814 		return ret;
815 	/*
816 	 * Query host supported protocol version.
817 	 */
818 
819 	for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
820 		/* reuse the packet for version range supported */
821 		memset(vstor_packet, 0, sizeof(struct vstor_packet));
822 		vstor_packet->operation =
823 			VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
824 
825 		vstor_packet->version.major_minor =
826 			vmstor_protocols[i].protocol_version;
827 
828 		/*
829 		 * The revision number is only used in Windows; set it to 0.
830 		 */
831 		vstor_packet->version.revision = 0;
832 		ret = storvsc_execute_vstor_op(device, request, false);
833 		if (ret != 0)
834 			return ret;
835 
836 		if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
837 			return -EINVAL;
838 
839 		if (vstor_packet->status == 0) {
840 			vmstor_proto_version =
841 				vmstor_protocols[i].protocol_version;
842 
843 			sense_buffer_size =
844 				vmstor_protocols[i].sense_buffer_size;
845 
846 			vmscsi_size_delta =
847 				vmstor_protocols[i].vmscsi_size_delta;
848 
849 			break;
850 		}
851 	}
852 
853 	if (vstor_packet->status != 0)
854 		return -EINVAL;
855 
856 
857 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
858 	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
859 	ret = storvsc_execute_vstor_op(device, request, true);
860 	if (ret != 0)
861 		return ret;
862 
863 	/*
864 	 * Check to see if multi-channel support is there.
865 	 * Hosts that implement protocol version of 5.1 and above
866 	 * support multi-channel.
867 	 */
868 	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
869 
870 	/*
871 	 * Allocate state to manage the sub-channels.
872 	 * We allocate an array based on the numbers of possible CPUs
873 	 * (Hyper-V does not support cpu online/offline).
874 	 * This Array will be sparseley populated with unique
875 	 * channels - primary + sub-channels.
876 	 * We will however populate all the slots to evenly distribute
877 	 * the load.
878 	 */
879 	stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
880 					 GFP_KERNEL);
881 	if (stor_device->stor_chns == NULL)
882 		return -ENOMEM;
883 
884 	stor_device->stor_chns[device->channel->target_cpu] = device->channel;
885 	cpumask_set_cpu(device->channel->target_cpu,
886 			&stor_device->alloced_cpus);
887 
888 	if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
889 		if (vstor_packet->storage_channel_properties.flags &
890 		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
891 			process_sub_channels = true;
892 	}
893 	stor_device->max_transfer_bytes =
894 		vstor_packet->storage_channel_properties.max_transfer_bytes;
895 
896 	if (!is_fc)
897 		goto done;
898 
899 	/*
900 	 * For FC devices retrieve FC HBA data.
901 	 */
902 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
903 	vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
904 	ret = storvsc_execute_vstor_op(device, request, true);
905 	if (ret != 0)
906 		return ret;
907 
908 	/*
909 	 * Cache the currently active port and node ww names.
910 	 */
911 	cache_wwn(stor_device, vstor_packet);
912 
913 done:
914 
915 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
916 	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
917 	ret = storvsc_execute_vstor_op(device, request, true);
918 	if (ret != 0)
919 		return ret;
920 
921 	if (process_sub_channels)
922 		handle_multichannel_storage(device, max_chns);
923 
924 	return ret;
925 }
926 
storvsc_handle_error(struct vmscsi_request * vm_srb,struct scsi_cmnd * scmnd,struct Scsi_Host * host,u8 asc,u8 ascq)927 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
928 				struct scsi_cmnd *scmnd,
929 				struct Scsi_Host *host,
930 				u8 asc, u8 ascq)
931 {
932 	struct storvsc_scan_work *wrk;
933 	void (*process_err_fn)(struct work_struct *work);
934 	bool do_work = false;
935 
936 	switch (SRB_STATUS(vm_srb->srb_status)) {
937 	case SRB_STATUS_ERROR:
938 		/*
939 		 * Let upper layer deal with error when
940 		 * sense message is present.
941 		 */
942 
943 		if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
944 			break;
945 		/*
946 		 * If there is an error; offline the device since all
947 		 * error recovery strategies would have already been
948 		 * deployed on the host side. However, if the command
949 		 * were a pass-through command deal with it appropriately.
950 		 */
951 		switch (scmnd->cmnd[0]) {
952 		case ATA_16:
953 		case ATA_12:
954 			set_host_byte(scmnd, DID_PASSTHROUGH);
955 			break;
956 		/*
957 		 * On Some Windows hosts TEST_UNIT_READY command can return
958 		 * SRB_STATUS_ERROR, let the upper level code deal with it
959 		 * based on the sense information.
960 		 */
961 		case TEST_UNIT_READY:
962 			break;
963 		default:
964 			set_host_byte(scmnd, DID_ERROR);
965 		}
966 		break;
967 	case SRB_STATUS_INVALID_LUN:
968 		set_host_byte(scmnd, DID_NO_CONNECT);
969 		do_work = true;
970 		process_err_fn = storvsc_remove_lun;
971 		break;
972 	case SRB_STATUS_ABORTED:
973 		if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
974 		    (asc == 0x2a) && (ascq == 0x9)) {
975 			do_work = true;
976 			process_err_fn = storvsc_device_scan;
977 			/*
978 			 * Retry the I/O that trigerred this.
979 			 */
980 			set_host_byte(scmnd, DID_REQUEUE);
981 		}
982 		break;
983 	}
984 
985 	if (!do_work)
986 		return;
987 
988 	/*
989 	 * We need to schedule work to process this error; schedule it.
990 	 */
991 	wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
992 	if (!wrk) {
993 		set_host_byte(scmnd, DID_TARGET_FAILURE);
994 		return;
995 	}
996 
997 	wrk->host = host;
998 	wrk->lun = vm_srb->lun;
999 	wrk->tgt_id = vm_srb->target_id;
1000 	INIT_WORK(&wrk->work, process_err_fn);
1001 	schedule_work(&wrk->work);
1002 }
1003 
1004 
storvsc_command_completion(struct storvsc_cmd_request * cmd_request,struct storvsc_device * stor_dev)1005 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1006 				       struct storvsc_device *stor_dev)
1007 {
1008 	struct scsi_cmnd *scmnd = cmd_request->cmd;
1009 	struct scsi_sense_hdr sense_hdr;
1010 	struct vmscsi_request *vm_srb;
1011 	u32 data_transfer_length;
1012 	struct Scsi_Host *host;
1013 	u32 payload_sz = cmd_request->payload_sz;
1014 	void *payload = cmd_request->payload;
1015 
1016 	host = stor_dev->host;
1017 
1018 	vm_srb = &cmd_request->vstor_packet.vm_srb;
1019 	data_transfer_length = vm_srb->data_transfer_length;
1020 
1021 	scmnd->result = vm_srb->scsi_status;
1022 
1023 	if (scmnd->result) {
1024 		if (scsi_normalize_sense(scmnd->sense_buffer,
1025 				SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1026 		    !(sense_hdr.sense_key == NOT_READY &&
1027 				 sense_hdr.asc == 0x03A) &&
1028 		    do_logging(STORVSC_LOGGING_ERROR))
1029 			scsi_print_sense_hdr(scmnd->device, "storvsc",
1030 					     &sense_hdr);
1031 	}
1032 
1033 	if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1034 		storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1035 					 sense_hdr.ascq);
1036 		/*
1037 		 * The Windows driver set data_transfer_length on
1038 		 * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1039 		 * is untouched.  In these cases we set it to 0.
1040 		 */
1041 		if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1042 			data_transfer_length = 0;
1043 	}
1044 
1045 	scsi_set_resid(scmnd,
1046 		cmd_request->payload->range.len - data_transfer_length);
1047 
1048 	scmnd->scsi_done(scmnd);
1049 
1050 	if (payload_sz >
1051 		sizeof(struct vmbus_channel_packet_multipage_buffer))
1052 		kfree(payload);
1053 }
1054 
storvsc_on_io_completion(struct storvsc_device * stor_device,struct vstor_packet * vstor_packet,struct storvsc_cmd_request * request)1055 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1056 				  struct vstor_packet *vstor_packet,
1057 				  struct storvsc_cmd_request *request)
1058 {
1059 	struct vstor_packet *stor_pkt;
1060 	struct hv_device *device = stor_device->device;
1061 
1062 	stor_pkt = &request->vstor_packet;
1063 
1064 	/*
1065 	 * The current SCSI handling on the host side does
1066 	 * not correctly handle:
1067 	 * INQUIRY command with page code parameter set to 0x80
1068 	 * MODE_SENSE command with cmd[2] == 0x1c
1069 	 *
1070 	 * Setup srb and scsi status so this won't be fatal.
1071 	 * We do this so we can distinguish truly fatal failues
1072 	 * (srb status == 0x4) and off-line the device in that case.
1073 	 */
1074 
1075 	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1076 	   (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1077 		vstor_packet->vm_srb.scsi_status = 0;
1078 		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1079 	}
1080 
1081 
1082 	/* Copy over the status...etc */
1083 	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1084 	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1085 	stor_pkt->vm_srb.sense_info_length =
1086 	vstor_packet->vm_srb.sense_info_length;
1087 
1088 	if (vstor_packet->vm_srb.scsi_status != 0 ||
1089 	    vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1090 		storvsc_log(device, STORVSC_LOGGING_WARN,
1091 			"cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1092 			stor_pkt->vm_srb.cdb[0],
1093 			vstor_packet->vm_srb.scsi_status,
1094 			vstor_packet->vm_srb.srb_status);
1095 
1096 	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1097 		/* CHECK_CONDITION */
1098 		if (vstor_packet->vm_srb.srb_status &
1099 			SRB_STATUS_AUTOSENSE_VALID) {
1100 			/* autosense data available */
1101 
1102 			storvsc_log(device, STORVSC_LOGGING_WARN,
1103 				"stor pkt %p autosense data valid - len %d\n",
1104 				request, vstor_packet->vm_srb.sense_info_length);
1105 
1106 			memcpy(request->cmd->sense_buffer,
1107 			       vstor_packet->vm_srb.sense_data,
1108 			       vstor_packet->vm_srb.sense_info_length);
1109 
1110 		}
1111 	}
1112 
1113 	stor_pkt->vm_srb.data_transfer_length =
1114 	vstor_packet->vm_srb.data_transfer_length;
1115 
1116 	storvsc_command_completion(request, stor_device);
1117 
1118 	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1119 		stor_device->drain_notify)
1120 		wake_up(&stor_device->waiting_to_drain);
1121 
1122 
1123 }
1124 
storvsc_on_receive(struct storvsc_device * stor_device,struct vstor_packet * vstor_packet,struct storvsc_cmd_request * request)1125 static void storvsc_on_receive(struct storvsc_device *stor_device,
1126 			     struct vstor_packet *vstor_packet,
1127 			     struct storvsc_cmd_request *request)
1128 {
1129 	struct storvsc_scan_work *work;
1130 
1131 	switch (vstor_packet->operation) {
1132 	case VSTOR_OPERATION_COMPLETE_IO:
1133 		storvsc_on_io_completion(stor_device, vstor_packet, request);
1134 		break;
1135 
1136 	case VSTOR_OPERATION_REMOVE_DEVICE:
1137 	case VSTOR_OPERATION_ENUMERATE_BUS:
1138 		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1139 		if (!work)
1140 			return;
1141 
1142 		INIT_WORK(&work->work, storvsc_host_scan);
1143 		work->host = stor_device->host;
1144 		schedule_work(&work->work);
1145 		break;
1146 
1147 	case VSTOR_OPERATION_FCHBA_DATA:
1148 		cache_wwn(stor_device, vstor_packet);
1149 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1150 		fc_host_node_name(stor_device->host) = stor_device->node_name;
1151 		fc_host_port_name(stor_device->host) = stor_device->port_name;
1152 #endif
1153 		break;
1154 	default:
1155 		break;
1156 	}
1157 }
1158 
storvsc_on_channel_callback(void * context)1159 static void storvsc_on_channel_callback(void *context)
1160 {
1161 	struct vmbus_channel *channel = (struct vmbus_channel *)context;
1162 	const struct vmpacket_descriptor *desc;
1163 	struct hv_device *device;
1164 	struct storvsc_device *stor_device;
1165 
1166 	if (channel->primary_channel != NULL)
1167 		device = channel->primary_channel->device_obj;
1168 	else
1169 		device = channel->device_obj;
1170 
1171 	stor_device = get_in_stor_device(device);
1172 	if (!stor_device)
1173 		return;
1174 
1175 	foreach_vmbus_pkt(desc, channel) {
1176 		void *packet = hv_pkt_data(desc);
1177 		struct storvsc_cmd_request *request;
1178 
1179 		request = (struct storvsc_cmd_request *)
1180 			((unsigned long)desc->trans_id);
1181 
1182 		if (request == &stor_device->init_request ||
1183 		    request == &stor_device->reset_request) {
1184 			memcpy(&request->vstor_packet, packet,
1185 			       (sizeof(struct vstor_packet) - vmscsi_size_delta));
1186 			complete(&request->wait_event);
1187 		} else {
1188 			storvsc_on_receive(stor_device, packet, request);
1189 		}
1190 	}
1191 }
1192 
storvsc_connect_to_vsp(struct hv_device * device,u32 ring_size,bool is_fc)1193 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1194 				  bool is_fc)
1195 {
1196 	struct vmstorage_channel_properties props;
1197 	int ret;
1198 
1199 	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1200 
1201 	ret = vmbus_open(device->channel,
1202 			 ring_size,
1203 			 ring_size,
1204 			 (void *)&props,
1205 			 sizeof(struct vmstorage_channel_properties),
1206 			 storvsc_on_channel_callback, device->channel);
1207 
1208 	if (ret != 0)
1209 		return ret;
1210 
1211 	ret = storvsc_channel_init(device, is_fc);
1212 
1213 	return ret;
1214 }
1215 
storvsc_dev_remove(struct hv_device * device)1216 static int storvsc_dev_remove(struct hv_device *device)
1217 {
1218 	struct storvsc_device *stor_device;
1219 
1220 	stor_device = hv_get_drvdata(device);
1221 
1222 	stor_device->destroy = true;
1223 
1224 	/* Make sure flag is set before waiting */
1225 	wmb();
1226 
1227 	/*
1228 	 * At this point, all outbound traffic should be disable. We
1229 	 * only allow inbound traffic (responses) to proceed so that
1230 	 * outstanding requests can be completed.
1231 	 */
1232 
1233 	storvsc_wait_to_drain(stor_device);
1234 
1235 	/*
1236 	 * Since we have already drained, we don't need to busy wait
1237 	 * as was done in final_release_stor_device()
1238 	 * Note that we cannot set the ext pointer to NULL until
1239 	 * we have drained - to drain the outgoing packets, we need to
1240 	 * allow incoming packets.
1241 	 */
1242 	hv_set_drvdata(device, NULL);
1243 
1244 	/* Close the channel */
1245 	vmbus_close(device->channel);
1246 
1247 	kfree(stor_device->stor_chns);
1248 	kfree(stor_device);
1249 	return 0;
1250 }
1251 
get_og_chn(struct storvsc_device * stor_device,u16 q_num)1252 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1253 					u16 q_num)
1254 {
1255 	u16 slot = 0;
1256 	u16 hash_qnum;
1257 	struct cpumask alloced_mask;
1258 	int num_channels, tgt_cpu;
1259 
1260 	if (stor_device->num_sc == 0)
1261 		return stor_device->device->channel;
1262 
1263 	/*
1264 	 * Our channel array is sparsley populated and we
1265 	 * initiated I/O on a processor/hw-q that does not
1266 	 * currently have a designated channel. Fix this.
1267 	 * The strategy is simple:
1268 	 * I. Ensure NUMA locality
1269 	 * II. Distribute evenly (best effort)
1270 	 * III. Mapping is persistent.
1271 	 */
1272 
1273 	cpumask_and(&alloced_mask, &stor_device->alloced_cpus,
1274 		    cpumask_of_node(cpu_to_node(q_num)));
1275 
1276 	num_channels = cpumask_weight(&alloced_mask);
1277 	if (num_channels == 0)
1278 		return stor_device->device->channel;
1279 
1280 	hash_qnum = q_num;
1281 	while (hash_qnum >= num_channels)
1282 		hash_qnum -= num_channels;
1283 
1284 	for_each_cpu(tgt_cpu, &alloced_mask) {
1285 		if (slot == hash_qnum)
1286 			break;
1287 		slot++;
1288 	}
1289 
1290 	stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1291 
1292 	return stor_device->stor_chns[q_num];
1293 }
1294 
1295 
storvsc_do_io(struct hv_device * device,struct storvsc_cmd_request * request,u16 q_num)1296 static int storvsc_do_io(struct hv_device *device,
1297 			 struct storvsc_cmd_request *request, u16 q_num)
1298 {
1299 	struct storvsc_device *stor_device;
1300 	struct vstor_packet *vstor_packet;
1301 	struct vmbus_channel *outgoing_channel;
1302 	int ret = 0;
1303 	struct cpumask alloced_mask;
1304 	int tgt_cpu;
1305 
1306 	vstor_packet = &request->vstor_packet;
1307 	stor_device = get_out_stor_device(device);
1308 
1309 	if (!stor_device)
1310 		return -ENODEV;
1311 
1312 
1313 	request->device  = device;
1314 	/*
1315 	 * Select an an appropriate channel to send the request out.
1316 	 */
1317 
1318 	if (stor_device->stor_chns[q_num] != NULL) {
1319 		outgoing_channel = stor_device->stor_chns[q_num];
1320 		if (outgoing_channel->target_cpu == smp_processor_id()) {
1321 			/*
1322 			 * Ideally, we want to pick a different channel if
1323 			 * available on the same NUMA node.
1324 			 */
1325 			cpumask_and(&alloced_mask, &stor_device->alloced_cpus,
1326 				    cpumask_of_node(cpu_to_node(q_num)));
1327 			for_each_cpu(tgt_cpu, &alloced_mask) {
1328 				if (tgt_cpu != outgoing_channel->target_cpu) {
1329 					outgoing_channel =
1330 					stor_device->stor_chns[tgt_cpu];
1331 					break;
1332 				}
1333 			}
1334 		}
1335 	} else {
1336 		outgoing_channel = get_og_chn(stor_device, q_num);
1337 	}
1338 
1339 
1340 	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1341 
1342 	vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1343 					vmscsi_size_delta);
1344 
1345 
1346 	vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1347 
1348 
1349 	vstor_packet->vm_srb.data_transfer_length =
1350 	request->payload->range.len;
1351 
1352 	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1353 
1354 	if (request->payload->range.len) {
1355 
1356 		ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1357 				request->payload, request->payload_sz,
1358 				vstor_packet,
1359 				(sizeof(struct vstor_packet) -
1360 				vmscsi_size_delta),
1361 				(unsigned long)request);
1362 	} else {
1363 		ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1364 			       (sizeof(struct vstor_packet) -
1365 				vmscsi_size_delta),
1366 			       (unsigned long)request,
1367 			       VM_PKT_DATA_INBAND,
1368 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1369 	}
1370 
1371 	if (ret != 0)
1372 		return ret;
1373 
1374 	atomic_inc(&stor_device->num_outstanding_req);
1375 
1376 	return ret;
1377 }
1378 
storvsc_device_alloc(struct scsi_device * sdevice)1379 static int storvsc_device_alloc(struct scsi_device *sdevice)
1380 {
1381 	/*
1382 	 * Set blist flag to permit the reading of the VPD pages even when
1383 	 * the target may claim SPC-2 compliance. MSFT targets currently
1384 	 * claim SPC-2 compliance while they implement post SPC-2 features.
1385 	 * With this flag we can correctly handle WRITE_SAME_16 issues.
1386 	 *
1387 	 * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1388 	 * still supports REPORT LUN.
1389 	 */
1390 	sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1391 
1392 	return 0;
1393 }
1394 
storvsc_device_configure(struct scsi_device * sdevice)1395 static int storvsc_device_configure(struct scsi_device *sdevice)
1396 {
1397 
1398 	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1399 
1400 	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1401 
1402 	/* Ensure there are no gaps in presented sgls */
1403 	blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1404 
1405 	sdevice->no_write_same = 1;
1406 
1407 	/*
1408 	 * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1409 	 * if the device is a MSFT virtual device.  If the host is
1410 	 * WIN10 or newer, allow write_same.
1411 	 */
1412 	if (!strncmp(sdevice->vendor, "Msft", 4)) {
1413 		switch (vmstor_proto_version) {
1414 		case VMSTOR_PROTO_VERSION_WIN8:
1415 		case VMSTOR_PROTO_VERSION_WIN8_1:
1416 			sdevice->scsi_level = SCSI_SPC_3;
1417 			break;
1418 		}
1419 
1420 		if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1421 			sdevice->no_write_same = 0;
1422 	}
1423 
1424 	return 0;
1425 }
1426 
storvsc_get_chs(struct scsi_device * sdev,struct block_device * bdev,sector_t capacity,int * info)1427 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1428 			   sector_t capacity, int *info)
1429 {
1430 	sector_t nsect = capacity;
1431 	sector_t cylinders = nsect;
1432 	int heads, sectors_pt;
1433 
1434 	/*
1435 	 * We are making up these values; let us keep it simple.
1436 	 */
1437 	heads = 0xff;
1438 	sectors_pt = 0x3f;      /* Sectors per track */
1439 	sector_div(cylinders, heads * sectors_pt);
1440 	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1441 		cylinders = 0xffff;
1442 
1443 	info[0] = heads;
1444 	info[1] = sectors_pt;
1445 	info[2] = (int)cylinders;
1446 
1447 	return 0;
1448 }
1449 
storvsc_host_reset_handler(struct scsi_cmnd * scmnd)1450 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1451 {
1452 	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1453 	struct hv_device *device = host_dev->dev;
1454 
1455 	struct storvsc_device *stor_device;
1456 	struct storvsc_cmd_request *request;
1457 	struct vstor_packet *vstor_packet;
1458 	int ret, t;
1459 
1460 
1461 	stor_device = get_out_stor_device(device);
1462 	if (!stor_device)
1463 		return FAILED;
1464 
1465 	request = &stor_device->reset_request;
1466 	vstor_packet = &request->vstor_packet;
1467 
1468 	init_completion(&request->wait_event);
1469 
1470 	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1471 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1472 	vstor_packet->vm_srb.path_id = stor_device->path_id;
1473 
1474 	ret = vmbus_sendpacket(device->channel, vstor_packet,
1475 			       (sizeof(struct vstor_packet) -
1476 				vmscsi_size_delta),
1477 			       (unsigned long)&stor_device->reset_request,
1478 			       VM_PKT_DATA_INBAND,
1479 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1480 	if (ret != 0)
1481 		return FAILED;
1482 
1483 	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1484 	if (t == 0)
1485 		return TIMEOUT_ERROR;
1486 
1487 
1488 	/*
1489 	 * At this point, all outstanding requests in the adapter
1490 	 * should have been flushed out and return to us
1491 	 * There is a potential race here where the host may be in
1492 	 * the process of responding when we return from here.
1493 	 * Just wait for all in-transit packets to be accounted for
1494 	 * before we return from here.
1495 	 */
1496 	storvsc_wait_to_drain(stor_device);
1497 
1498 	return SUCCESS;
1499 }
1500 
1501 /*
1502  * The host guarantees to respond to each command, although I/O latencies might
1503  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1504  * chance to perform EH.
1505  */
storvsc_eh_timed_out(struct scsi_cmnd * scmnd)1506 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1507 {
1508 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1509 	if (scmnd->device->host->transportt == fc_transport_template)
1510 		return fc_eh_timed_out(scmnd);
1511 #endif
1512 	return BLK_EH_RESET_TIMER;
1513 }
1514 
storvsc_scsi_cmd_ok(struct scsi_cmnd * scmnd)1515 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1516 {
1517 	bool allowed = true;
1518 	u8 scsi_op = scmnd->cmnd[0];
1519 
1520 	switch (scsi_op) {
1521 	/* the host does not handle WRITE_SAME, log accident usage */
1522 	case WRITE_SAME:
1523 	/*
1524 	 * smartd sends this command and the host does not handle
1525 	 * this. So, don't send it.
1526 	 */
1527 	case SET_WINDOW:
1528 		scmnd->result = ILLEGAL_REQUEST << 16;
1529 		allowed = false;
1530 		break;
1531 	default:
1532 		break;
1533 	}
1534 	return allowed;
1535 }
1536 
storvsc_queuecommand(struct Scsi_Host * host,struct scsi_cmnd * scmnd)1537 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1538 {
1539 	int ret;
1540 	struct hv_host_device *host_dev = shost_priv(host);
1541 	struct hv_device *dev = host_dev->dev;
1542 	struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1543 	int i;
1544 	struct scatterlist *sgl;
1545 	unsigned int sg_count = 0;
1546 	struct vmscsi_request *vm_srb;
1547 	struct scatterlist *cur_sgl;
1548 	struct vmbus_packet_mpb_array  *payload;
1549 	u32 payload_sz;
1550 	u32 length;
1551 
1552 	if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1553 		/*
1554 		 * On legacy hosts filter unimplemented commands.
1555 		 * Future hosts are expected to correctly handle
1556 		 * unsupported commands. Furthermore, it is
1557 		 * possible that some of the currently
1558 		 * unsupported commands maybe supported in
1559 		 * future versions of the host.
1560 		 */
1561 		if (!storvsc_scsi_cmd_ok(scmnd)) {
1562 			scmnd->scsi_done(scmnd);
1563 			return 0;
1564 		}
1565 	}
1566 
1567 	/* Setup the cmd request */
1568 	cmd_request->cmd = scmnd;
1569 
1570 	vm_srb = &cmd_request->vstor_packet.vm_srb;
1571 	vm_srb->win8_extension.time_out_value = 60;
1572 
1573 	vm_srb->win8_extension.srb_flags |=
1574 		SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1575 
1576 	if (scmnd->device->tagged_supported) {
1577 		vm_srb->win8_extension.srb_flags |=
1578 		(SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1579 		vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1580 		vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1581 	}
1582 
1583 	/* Build the SRB */
1584 	switch (scmnd->sc_data_direction) {
1585 	case DMA_TO_DEVICE:
1586 		vm_srb->data_in = WRITE_TYPE;
1587 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1588 		break;
1589 	case DMA_FROM_DEVICE:
1590 		vm_srb->data_in = READ_TYPE;
1591 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1592 		break;
1593 	case DMA_NONE:
1594 		vm_srb->data_in = UNKNOWN_TYPE;
1595 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1596 		break;
1597 	default:
1598 		/*
1599 		 * This is DMA_BIDIRECTIONAL or something else we are never
1600 		 * supposed to see here.
1601 		 */
1602 		WARN(1, "Unexpected data direction: %d\n",
1603 		     scmnd->sc_data_direction);
1604 		return -EINVAL;
1605 	}
1606 
1607 
1608 	vm_srb->port_number = host_dev->port;
1609 	vm_srb->path_id = scmnd->device->channel;
1610 	vm_srb->target_id = scmnd->device->id;
1611 	vm_srb->lun = scmnd->device->lun;
1612 
1613 	vm_srb->cdb_length = scmnd->cmd_len;
1614 
1615 	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1616 
1617 	sgl = (struct scatterlist *)scsi_sglist(scmnd);
1618 	sg_count = scsi_sg_count(scmnd);
1619 
1620 	length = scsi_bufflen(scmnd);
1621 	payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1622 	payload_sz = sizeof(cmd_request->mpb);
1623 
1624 	if (sg_count) {
1625 		if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1626 
1627 			payload_sz = (sg_count * sizeof(u64) +
1628 				      sizeof(struct vmbus_packet_mpb_array));
1629 			payload = kzalloc(payload_sz, GFP_ATOMIC);
1630 			if (!payload)
1631 				return SCSI_MLQUEUE_DEVICE_BUSY;
1632 		}
1633 
1634 		payload->range.len = length;
1635 		payload->range.offset = sgl[0].offset;
1636 
1637 		cur_sgl = sgl;
1638 		for (i = 0; i < sg_count; i++) {
1639 			payload->range.pfn_array[i] =
1640 				page_to_pfn(sg_page((cur_sgl)));
1641 			cur_sgl = sg_next(cur_sgl);
1642 		}
1643 	}
1644 
1645 	cmd_request->payload = payload;
1646 	cmd_request->payload_sz = payload_sz;
1647 
1648 	/* Invokes the vsc to start an IO */
1649 	ret = storvsc_do_io(dev, cmd_request, get_cpu());
1650 	put_cpu();
1651 
1652 	if (ret == -EAGAIN) {
1653 		if (payload_sz > sizeof(cmd_request->mpb))
1654 			kfree(payload);
1655 		/* no more space */
1656 		return SCSI_MLQUEUE_DEVICE_BUSY;
1657 	}
1658 
1659 	return 0;
1660 }
1661 
1662 static struct scsi_host_template scsi_driver = {
1663 	.module	=		THIS_MODULE,
1664 	.name =			"storvsc_host_t",
1665 	.cmd_size =             sizeof(struct storvsc_cmd_request),
1666 	.bios_param =		storvsc_get_chs,
1667 	.queuecommand =		storvsc_queuecommand,
1668 	.eh_host_reset_handler =	storvsc_host_reset_handler,
1669 	.proc_name =		"storvsc_host",
1670 	.eh_timed_out =		storvsc_eh_timed_out,
1671 	.slave_alloc =		storvsc_device_alloc,
1672 	.slave_configure =	storvsc_device_configure,
1673 	.cmd_per_lun =		2048,
1674 	.this_id =		-1,
1675 	.use_clustering =	ENABLE_CLUSTERING,
1676 	/* Make sure we dont get a sg segment crosses a page boundary */
1677 	.dma_boundary =		PAGE_SIZE-1,
1678 	.no_write_same =	1,
1679 	.track_queue_depth =	1,
1680 };
1681 
1682 enum {
1683 	SCSI_GUID,
1684 	IDE_GUID,
1685 	SFC_GUID,
1686 };
1687 
1688 static const struct hv_vmbus_device_id id_table[] = {
1689 	/* SCSI guid */
1690 	{ HV_SCSI_GUID,
1691 	  .driver_data = SCSI_GUID
1692 	},
1693 	/* IDE guid */
1694 	{ HV_IDE_GUID,
1695 	  .driver_data = IDE_GUID
1696 	},
1697 	/* Fibre Channel GUID */
1698 	{
1699 	  HV_SYNTHFC_GUID,
1700 	  .driver_data = SFC_GUID
1701 	},
1702 	{ },
1703 };
1704 
1705 MODULE_DEVICE_TABLE(vmbus, id_table);
1706 
storvsc_probe(struct hv_device * device,const struct hv_vmbus_device_id * dev_id)1707 static int storvsc_probe(struct hv_device *device,
1708 			const struct hv_vmbus_device_id *dev_id)
1709 {
1710 	int ret;
1711 	int num_cpus = num_online_cpus();
1712 	struct Scsi_Host *host;
1713 	struct hv_host_device *host_dev;
1714 	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1715 	bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1716 	int target = 0;
1717 	struct storvsc_device *stor_device;
1718 	int max_luns_per_target;
1719 	int max_targets;
1720 	int max_channels;
1721 	int max_sub_channels = 0;
1722 
1723 	/*
1724 	 * Based on the windows host we are running on,
1725 	 * set state to properly communicate with the host.
1726 	 */
1727 
1728 	if (vmbus_proto_version < VERSION_WIN8) {
1729 		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1730 		max_targets = STORVSC_IDE_MAX_TARGETS;
1731 		max_channels = STORVSC_IDE_MAX_CHANNELS;
1732 	} else {
1733 		max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1734 		max_targets = STORVSC_MAX_TARGETS;
1735 		max_channels = STORVSC_MAX_CHANNELS;
1736 		/*
1737 		 * On Windows8 and above, we support sub-channels for storage
1738 		 * on SCSI and FC controllers.
1739 		 * The number of sub-channels offerred is based on the number of
1740 		 * VCPUs in the guest.
1741 		 */
1742 		if (!dev_is_ide)
1743 			max_sub_channels =
1744 				(num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1745 	}
1746 
1747 	scsi_driver.can_queue = (max_outstanding_req_per_channel *
1748 				 (max_sub_channels + 1));
1749 
1750 	host = scsi_host_alloc(&scsi_driver,
1751 			       sizeof(struct hv_host_device));
1752 	if (!host)
1753 		return -ENOMEM;
1754 
1755 	host_dev = shost_priv(host);
1756 	memset(host_dev, 0, sizeof(struct hv_host_device));
1757 
1758 	host_dev->port = host->host_no;
1759 	host_dev->dev = device;
1760 
1761 
1762 	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1763 	if (!stor_device) {
1764 		ret = -ENOMEM;
1765 		goto err_out0;
1766 	}
1767 
1768 	stor_device->destroy = false;
1769 	stor_device->open_sub_channel = false;
1770 	init_waitqueue_head(&stor_device->waiting_to_drain);
1771 	stor_device->device = device;
1772 	stor_device->host = host;
1773 	hv_set_drvdata(device, stor_device);
1774 
1775 	stor_device->port_number = host->host_no;
1776 	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1777 	if (ret)
1778 		goto err_out1;
1779 
1780 	host_dev->path = stor_device->path_id;
1781 	host_dev->target = stor_device->target_id;
1782 
1783 	switch (dev_id->driver_data) {
1784 	case SFC_GUID:
1785 		host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1786 		host->max_id = STORVSC_FC_MAX_TARGETS;
1787 		host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1788 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1789 		host->transportt = fc_transport_template;
1790 #endif
1791 		break;
1792 
1793 	case SCSI_GUID:
1794 		host->max_lun = max_luns_per_target;
1795 		host->max_id = max_targets;
1796 		host->max_channel = max_channels - 1;
1797 		break;
1798 
1799 	default:
1800 		host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1801 		host->max_id = STORVSC_IDE_MAX_TARGETS;
1802 		host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1803 		break;
1804 	}
1805 	/* max cmd length */
1806 	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1807 
1808 	/*
1809 	 * set the table size based on the info we got
1810 	 * from the host.
1811 	 */
1812 	host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1813 	/*
1814 	 * Set the number of HW queues we are supporting.
1815 	 */
1816 	if (stor_device->num_sc != 0)
1817 		host->nr_hw_queues = stor_device->num_sc + 1;
1818 
1819 	/* Register the HBA and start the scsi bus scan */
1820 	ret = scsi_add_host(host, &device->device);
1821 	if (ret != 0)
1822 		goto err_out2;
1823 
1824 	if (!dev_is_ide) {
1825 		scsi_scan_host(host);
1826 	} else {
1827 		target = (device->dev_instance.b[5] << 8 |
1828 			 device->dev_instance.b[4]);
1829 		ret = scsi_add_device(host, 0, target, 0);
1830 		if (ret)
1831 			goto err_out3;
1832 	}
1833 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1834 	if (host->transportt == fc_transport_template) {
1835 		struct fc_rport_identifiers ids = {
1836 			.roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
1837 		};
1838 
1839 		fc_host_node_name(host) = stor_device->node_name;
1840 		fc_host_port_name(host) = stor_device->port_name;
1841 		stor_device->rport = fc_remote_port_add(host, 0, &ids);
1842 		if (!stor_device->rport) {
1843 			ret = -ENOMEM;
1844 			goto err_out3;
1845 		}
1846 	}
1847 #endif
1848 	return 0;
1849 
1850 err_out3:
1851 	scsi_remove_host(host);
1852 
1853 err_out2:
1854 	/*
1855 	 * Once we have connected with the host, we would need to
1856 	 * to invoke storvsc_dev_remove() to rollback this state and
1857 	 * this call also frees up the stor_device; hence the jump around
1858 	 * err_out1 label.
1859 	 */
1860 	storvsc_dev_remove(device);
1861 	goto err_out0;
1862 
1863 err_out1:
1864 	kfree(stor_device->stor_chns);
1865 	kfree(stor_device);
1866 
1867 err_out0:
1868 	scsi_host_put(host);
1869 	return ret;
1870 }
1871 
storvsc_remove(struct hv_device * dev)1872 static int storvsc_remove(struct hv_device *dev)
1873 {
1874 	struct storvsc_device *stor_device = hv_get_drvdata(dev);
1875 	struct Scsi_Host *host = stor_device->host;
1876 
1877 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1878 	if (host->transportt == fc_transport_template) {
1879 		fc_remote_port_delete(stor_device->rport);
1880 		fc_remove_host(host);
1881 	}
1882 #endif
1883 	scsi_remove_host(host);
1884 	storvsc_dev_remove(dev);
1885 	scsi_host_put(host);
1886 
1887 	return 0;
1888 }
1889 
1890 static struct hv_driver storvsc_drv = {
1891 	.name = KBUILD_MODNAME,
1892 	.id_table = id_table,
1893 	.probe = storvsc_probe,
1894 	.remove = storvsc_remove,
1895 };
1896 
1897 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1898 static struct fc_function_template fc_transport_functions = {
1899 	.show_host_node_name = 1,
1900 	.show_host_port_name = 1,
1901 };
1902 #endif
1903 
storvsc_drv_init(void)1904 static int __init storvsc_drv_init(void)
1905 {
1906 	int ret;
1907 
1908 	/*
1909 	 * Divide the ring buffer data size (which is 1 page less
1910 	 * than the ring buffer size since that page is reserved for
1911 	 * the ring buffer indices) by the max request size (which is
1912 	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1913 	 */
1914 	max_outstanding_req_per_channel =
1915 		((storvsc_ringbuffer_size - PAGE_SIZE) /
1916 		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1917 		sizeof(struct vstor_packet) + sizeof(u64) -
1918 		vmscsi_size_delta,
1919 		sizeof(u64)));
1920 
1921 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1922 	fc_transport_template = fc_attach_transport(&fc_transport_functions);
1923 	if (!fc_transport_template)
1924 		return -ENODEV;
1925 #endif
1926 
1927 	ret = vmbus_driver_register(&storvsc_drv);
1928 
1929 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1930 	if (ret)
1931 		fc_release_transport(fc_transport_template);
1932 #endif
1933 
1934 	return ret;
1935 }
1936 
storvsc_drv_exit(void)1937 static void __exit storvsc_drv_exit(void)
1938 {
1939 	vmbus_driver_unregister(&storvsc_drv);
1940 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1941 	fc_release_transport(fc_transport_template);
1942 #endif
1943 }
1944 
1945 MODULE_LICENSE("GPL");
1946 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1947 module_init(storvsc_drv_init);
1948 module_exit(storvsc_drv_exit);
1949