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
45/*
46 * All wire protocol details (storage protocol between the guest and the host)
47 * are consolidated here.
48 *
49 * Begin protocol definitions.
50 */
51
52/*
53 * Version history:
54 * V1 Beta: 0.1
55 * V1 RC < 2008/1/31: 1.0
56 * V1 RC > 2008/1/31:  2.0
57 * Win7: 4.2
58 * Win8: 5.1
59 */
60
61
62#define VMSTOR_WIN7_MAJOR 4
63#define VMSTOR_WIN7_MINOR 2
64
65#define VMSTOR_WIN8_MAJOR 5
66#define VMSTOR_WIN8_MINOR 1
67
68
69/*  Packet structure describing virtual storage requests. */
70enum vstor_packet_operation {
71	VSTOR_OPERATION_COMPLETE_IO		= 1,
72	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
73	VSTOR_OPERATION_EXECUTE_SRB		= 3,
74	VSTOR_OPERATION_RESET_LUN		= 4,
75	VSTOR_OPERATION_RESET_ADAPTER		= 5,
76	VSTOR_OPERATION_RESET_BUS		= 6,
77	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
78	VSTOR_OPERATION_END_INITIALIZATION	= 8,
79	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
80	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
81	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
82	VSTOR_OPERATION_FCHBA_DATA              = 12,
83	VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
84	VSTOR_OPERATION_MAXIMUM                 = 13
85};
86
87/*
88 * WWN packet for Fibre Channel HBA
89 */
90
91struct hv_fc_wwn_packet {
92	bool	primary_active;
93	u8	reserved1;
94	u8	reserved2;
95	u8	primary_port_wwn[8];
96	u8	primary_node_wwn[8];
97	u8	secondary_port_wwn[8];
98	u8	secondary_node_wwn[8];
99};
100
101
102
103/*
104 * SRB Flag Bits
105 */
106
107#define SRB_FLAGS_QUEUE_ACTION_ENABLE		0x00000002
108#define SRB_FLAGS_DISABLE_DISCONNECT		0x00000004
109#define SRB_FLAGS_DISABLE_SYNCH_TRANSFER	0x00000008
110#define SRB_FLAGS_BYPASS_FROZEN_QUEUE		0x00000010
111#define SRB_FLAGS_DISABLE_AUTOSENSE		0x00000020
112#define SRB_FLAGS_DATA_IN			0x00000040
113#define SRB_FLAGS_DATA_OUT			0x00000080
114#define SRB_FLAGS_NO_DATA_TRANSFER		0x00000000
115#define SRB_FLAGS_UNSPECIFIED_DIRECTION	(SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
116#define SRB_FLAGS_NO_QUEUE_FREEZE		0x00000100
117#define SRB_FLAGS_ADAPTER_CACHE_ENABLE		0x00000200
118#define SRB_FLAGS_FREE_SENSE_BUFFER		0x00000400
119
120/*
121 * This flag indicates the request is part of the workflow for processing a D3.
122 */
123#define SRB_FLAGS_D3_PROCESSING			0x00000800
124#define SRB_FLAGS_IS_ACTIVE			0x00010000
125#define SRB_FLAGS_ALLOCATED_FROM_ZONE		0x00020000
126#define SRB_FLAGS_SGLIST_FROM_POOL		0x00040000
127#define SRB_FLAGS_BYPASS_LOCKED_QUEUE		0x00080000
128#define SRB_FLAGS_NO_KEEP_AWAKE			0x00100000
129#define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE	0x00200000
130#define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT	0x00400000
131#define SRB_FLAGS_DONT_START_NEXT_PACKET	0x00800000
132#define SRB_FLAGS_PORT_DRIVER_RESERVED		0x0F000000
133#define SRB_FLAGS_CLASS_DRIVER_RESERVED		0xF0000000
134
135
136/*
137 * Platform neutral description of a scsi request -
138 * this remains the same across the write regardless of 32/64 bit
139 * note: it's patterned off the SCSI_PASS_THROUGH structure
140 */
141#define STORVSC_MAX_CMD_LEN			0x10
142
143#define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE	0x14
144#define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE	0x12
145
146#define STORVSC_SENSE_BUFFER_SIZE		0x14
147#define STORVSC_MAX_BUF_LEN_WITH_PADDING	0x14
148
149/*
150 * Sense buffer size changed in win8; have a run-time
151 * variable to track the size we should use.
152 */
153static int sense_buffer_size;
154
155/*
156 * The size of the vmscsi_request has changed in win8. The
157 * additional size is because of new elements added to the
158 * structure. These elements are valid only when we are talking
159 * to a win8 host.
160 * Track the correction to size we need to apply.
161 */
162
163static int vmscsi_size_delta;
164static int vmstor_current_major;
165static int vmstor_current_minor;
166
167struct vmscsi_win8_extension {
168	/*
169	 * The following were added in Windows 8
170	 */
171	u16 reserve;
172	u8  queue_tag;
173	u8  queue_action;
174	u32 srb_flags;
175	u32 time_out_value;
176	u32 queue_sort_ey;
177} __packed;
178
179struct vmscsi_request {
180	u16 length;
181	u8 srb_status;
182	u8 scsi_status;
183
184	u8  port_number;
185	u8  path_id;
186	u8  target_id;
187	u8  lun;
188
189	u8  cdb_length;
190	u8  sense_info_length;
191	u8  data_in;
192	u8  reserved;
193
194	u32 data_transfer_length;
195
196	union {
197		u8 cdb[STORVSC_MAX_CMD_LEN];
198		u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
199		u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
200	};
201	/*
202	 * The following was added in win8.
203	 */
204	struct vmscsi_win8_extension win8_extension;
205
206} __attribute((packed));
207
208
209/*
210 * This structure is sent during the intialization phase to get the different
211 * properties of the channel.
212 */
213
214#define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL		0x1
215
216struct vmstorage_channel_properties {
217	u32 reserved;
218	u16 max_channel_cnt;
219	u16 reserved1;
220
221	u32 flags;
222	u32   max_transfer_bytes;
223
224	u64  reserved2;
225} __packed;
226
227/*  This structure is sent during the storage protocol negotiations. */
228struct vmstorage_protocol_version {
229	/* Major (MSW) and minor (LSW) version numbers. */
230	u16 major_minor;
231
232	/*
233	 * Revision number is auto-incremented whenever this file is changed
234	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
235	 * definitely indicate incompatibility--but it does indicate mismatched
236	 * builds.
237	 * This is only used on the windows side. Just set it to 0.
238	 */
239	u16 revision;
240} __packed;
241
242/* Channel Property Flags */
243#define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
244#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
245
246struct vstor_packet {
247	/* Requested operation type */
248	enum vstor_packet_operation operation;
249
250	/*  Flags - see below for values */
251	u32 flags;
252
253	/* Status of the request returned from the server side. */
254	u32 status;
255
256	/* Data payload area */
257	union {
258		/*
259		 * Structure used to forward SCSI commands from the
260		 * client to the server.
261		 */
262		struct vmscsi_request vm_srb;
263
264		/* Structure used to query channel properties. */
265		struct vmstorage_channel_properties storage_channel_properties;
266
267		/* Used during version negotiations. */
268		struct vmstorage_protocol_version version;
269
270		/* Fibre channel address packet */
271		struct hv_fc_wwn_packet wwn_packet;
272
273		/* Number of sub-channels to create */
274		u16 sub_channel_count;
275
276		/* This will be the maximum of the union members */
277		u8  buffer[0x34];
278	};
279} __packed;
280
281/*
282 * Packet Flags:
283 *
284 * This flag indicates that the server should send back a completion for this
285 * packet.
286 */
287
288#define REQUEST_COMPLETION_FLAG	0x1
289
290/* Matches Windows-end */
291enum storvsc_request_type {
292	WRITE_TYPE = 0,
293	READ_TYPE,
294	UNKNOWN_TYPE,
295};
296
297/*
298 * SRB status codes and masks; a subset of the codes used here.
299 */
300
301#define SRB_STATUS_AUTOSENSE_VALID	0x80
302#define SRB_STATUS_INVALID_LUN	0x20
303#define SRB_STATUS_SUCCESS	0x01
304#define SRB_STATUS_ABORTED	0x02
305#define SRB_STATUS_ERROR	0x04
306
307/*
308 * This is the end of Protocol specific defines.
309 */
310
311static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
312static u32 max_outstanding_req_per_channel;
313
314static int storvsc_vcpus_per_sub_channel = 4;
315
316module_param(storvsc_ringbuffer_size, int, S_IRUGO);
317MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
318
319module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
320MODULE_PARM_DESC(vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
321/*
322 * Timeout in seconds for all devices managed by this driver.
323 */
324static int storvsc_timeout = 180;
325
326static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
327
328
329static void storvsc_on_channel_callback(void *context);
330
331#define STORVSC_MAX_LUNS_PER_TARGET			255
332#define STORVSC_MAX_TARGETS				2
333#define STORVSC_MAX_CHANNELS				8
334
335#define STORVSC_FC_MAX_LUNS_PER_TARGET			255
336#define STORVSC_FC_MAX_TARGETS				128
337#define STORVSC_FC_MAX_CHANNELS				8
338
339#define STORVSC_IDE_MAX_LUNS_PER_TARGET			64
340#define STORVSC_IDE_MAX_TARGETS				1
341#define STORVSC_IDE_MAX_CHANNELS			1
342
343struct storvsc_cmd_request {
344	struct scsi_cmnd *cmd;
345
346	unsigned int bounce_sgl_count;
347	struct scatterlist *bounce_sgl;
348
349	struct hv_device *device;
350
351	/* Synchronize the request/response if needed */
352	struct completion wait_event;
353
354	struct vmbus_channel_packet_multipage_buffer mpb;
355	struct vmbus_packet_mpb_array *payload;
356	u32 payload_sz;
357
358	struct vstor_packet vstor_packet;
359};
360
361
362/* A storvsc device is a device object that contains a vmbus channel */
363struct storvsc_device {
364	struct hv_device *device;
365
366	bool	 destroy;
367	bool	 drain_notify;
368	bool	 open_sub_channel;
369	atomic_t num_outstanding_req;
370	struct Scsi_Host *host;
371
372	wait_queue_head_t waiting_to_drain;
373
374	/*
375	 * Each unique Port/Path/Target represents 1 channel ie scsi
376	 * controller. In reality, the pathid, targetid is always 0
377	 * and the port is set by us
378	 */
379	unsigned int port_number;
380	unsigned char path_id;
381	unsigned char target_id;
382
383	/*
384	 * Max I/O, the device can support.
385	 */
386	u32   max_transfer_bytes;
387	/* Used for vsc/vsp channel reset process */
388	struct storvsc_cmd_request init_request;
389	struct storvsc_cmd_request reset_request;
390};
391
392struct hv_host_device {
393	struct hv_device *dev;
394	unsigned int port;
395	unsigned char path;
396	unsigned char target;
397};
398
399struct storvsc_scan_work {
400	struct work_struct work;
401	struct Scsi_Host *host;
402	uint lun;
403};
404
405static void storvsc_device_scan(struct work_struct *work)
406{
407	struct storvsc_scan_work *wrk;
408	uint lun;
409	struct scsi_device *sdev;
410
411	wrk = container_of(work, struct storvsc_scan_work, work);
412	lun = wrk->lun;
413
414	sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
415	if (!sdev)
416		goto done;
417	scsi_rescan_device(&sdev->sdev_gendev);
418	scsi_device_put(sdev);
419
420done:
421	kfree(wrk);
422}
423
424static void storvsc_host_scan(struct work_struct *work)
425{
426	struct storvsc_scan_work *wrk;
427	struct Scsi_Host *host;
428	struct scsi_device *sdev;
429	unsigned long flags;
430
431	wrk = container_of(work, struct storvsc_scan_work, work);
432	host = wrk->host;
433
434	/*
435	 * Before scanning the host, first check to see if any of the
436	 * currrently known devices have been hot removed. We issue a
437	 * "unit ready" command against all currently known devices.
438	 * This I/O will result in an error for devices that have been
439	 * removed. As part of handling the I/O error, we remove the device.
440	 *
441	 * When a LUN is added or removed, the host sends us a signal to
442	 * scan the host. Thus we are forced to discover the LUNs that
443	 * may have been removed this way.
444	 */
445	mutex_lock(&host->scan_mutex);
446	spin_lock_irqsave(host->host_lock, flags);
447	list_for_each_entry(sdev, &host->__devices, siblings) {
448		spin_unlock_irqrestore(host->host_lock, flags);
449		scsi_test_unit_ready(sdev, 1, 1, NULL);
450		spin_lock_irqsave(host->host_lock, flags);
451		continue;
452	}
453	spin_unlock_irqrestore(host->host_lock, flags);
454	mutex_unlock(&host->scan_mutex);
455	/*
456	 * Now scan the host to discover LUNs that may have been added.
457	 */
458	scsi_scan_host(host);
459
460	kfree(wrk);
461}
462
463static void storvsc_remove_lun(struct work_struct *work)
464{
465	struct storvsc_scan_work *wrk;
466	struct scsi_device *sdev;
467
468	wrk = container_of(work, struct storvsc_scan_work, work);
469	if (!scsi_host_get(wrk->host))
470		goto done;
471
472	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
473
474	if (sdev) {
475		scsi_remove_device(sdev);
476		scsi_device_put(sdev);
477	}
478	scsi_host_put(wrk->host);
479
480done:
481	kfree(wrk);
482}
483
484/*
485 * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
486 * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
487 */
488
489static inline u16 storvsc_get_version(u8 major, u8 minor)
490{
491	u16 version;
492
493	version = ((major << 8) | minor);
494	return version;
495}
496
497/*
498 * We can get incoming messages from the host that are not in response to
499 * messages that we have sent out. An example of this would be messages
500 * received by the guest to notify dynamic addition/removal of LUNs. To
501 * deal with potential race conditions where the driver may be in the
502 * midst of being unloaded when we might receive an unsolicited message
503 * from the host, we have implemented a mechanism to gurantee sequential
504 * consistency:
505 *
506 * 1) Once the device is marked as being destroyed, we will fail all
507 *    outgoing messages.
508 * 2) We permit incoming messages when the device is being destroyed,
509 *    only to properly account for messages already sent out.
510 */
511
512static inline struct storvsc_device *get_out_stor_device(
513					struct hv_device *device)
514{
515	struct storvsc_device *stor_device;
516
517	stor_device = hv_get_drvdata(device);
518
519	if (stor_device && stor_device->destroy)
520		stor_device = NULL;
521
522	return stor_device;
523}
524
525
526static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
527{
528	dev->drain_notify = true;
529	wait_event(dev->waiting_to_drain,
530		   atomic_read(&dev->num_outstanding_req) == 0);
531	dev->drain_notify = false;
532}
533
534static inline struct storvsc_device *get_in_stor_device(
535					struct hv_device *device)
536{
537	struct storvsc_device *stor_device;
538
539	stor_device = hv_get_drvdata(device);
540
541	if (!stor_device)
542		goto get_in_err;
543
544	/*
545	 * If the device is being destroyed; allow incoming
546	 * traffic only to cleanup outstanding requests.
547	 */
548
549	if (stor_device->destroy  &&
550		(atomic_read(&stor_device->num_outstanding_req) == 0))
551		stor_device = NULL;
552
553get_in_err:
554	return stor_device;
555
556}
557
558static void destroy_bounce_buffer(struct scatterlist *sgl,
559				  unsigned int sg_count)
560{
561	int i;
562	struct page *page_buf;
563
564	for (i = 0; i < sg_count; i++) {
565		page_buf = sg_page((&sgl[i]));
566		if (page_buf != NULL)
567			__free_page(page_buf);
568	}
569
570	kfree(sgl);
571}
572
573static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
574{
575	int i;
576
577	/* No need to check */
578	if (sg_count < 2)
579		return -1;
580
581	/* We have at least 2 sg entries */
582	for (i = 0; i < sg_count; i++) {
583		if (i == 0) {
584			/* make sure 1st one does not have hole */
585			if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
586				return i;
587		} else if (i == sg_count - 1) {
588			/* make sure last one does not have hole */
589			if (sgl[i].offset != 0)
590				return i;
591		} else {
592			/* make sure no hole in the middle */
593			if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
594				return i;
595		}
596	}
597	return -1;
598}
599
600static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
601						unsigned int sg_count,
602						unsigned int len,
603						int write)
604{
605	int i;
606	int num_pages;
607	struct scatterlist *bounce_sgl;
608	struct page *page_buf;
609	unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
610
611	num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
612
613	bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
614	if (!bounce_sgl)
615		return NULL;
616
617	sg_init_table(bounce_sgl, num_pages);
618	for (i = 0; i < num_pages; i++) {
619		page_buf = alloc_page(GFP_ATOMIC);
620		if (!page_buf)
621			goto cleanup;
622		sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
623	}
624
625	return bounce_sgl;
626
627cleanup:
628	destroy_bounce_buffer(bounce_sgl, num_pages);
629	return NULL;
630}
631
632/* Assume the original sgl has enough room */
633static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
634					    struct scatterlist *bounce_sgl,
635					    unsigned int orig_sgl_count,
636					    unsigned int bounce_sgl_count)
637{
638	int i;
639	int j = 0;
640	unsigned long src, dest;
641	unsigned int srclen, destlen, copylen;
642	unsigned int total_copied = 0;
643	unsigned long bounce_addr = 0;
644	unsigned long dest_addr = 0;
645	unsigned long flags;
646	struct scatterlist *cur_dest_sgl;
647	struct scatterlist *cur_src_sgl;
648
649	local_irq_save(flags);
650	cur_dest_sgl = orig_sgl;
651	cur_src_sgl = bounce_sgl;
652	for (i = 0; i < orig_sgl_count; i++) {
653		dest_addr = (unsigned long)
654				kmap_atomic(sg_page(cur_dest_sgl)) +
655				cur_dest_sgl->offset;
656		dest = dest_addr;
657		destlen = cur_dest_sgl->length;
658
659		if (bounce_addr == 0)
660			bounce_addr = (unsigned long)kmap_atomic(
661							sg_page(cur_src_sgl));
662
663		while (destlen) {
664			src = bounce_addr + cur_src_sgl->offset;
665			srclen = cur_src_sgl->length - cur_src_sgl->offset;
666
667			copylen = min(srclen, destlen);
668			memcpy((void *)dest, (void *)src, copylen);
669
670			total_copied += copylen;
671			cur_src_sgl->offset += copylen;
672			destlen -= copylen;
673			dest += copylen;
674
675			if (cur_src_sgl->offset == cur_src_sgl->length) {
676				/* full */
677				kunmap_atomic((void *)bounce_addr);
678				j++;
679
680				/*
681				 * It is possible that the number of elements
682				 * in the bounce buffer may not be equal to
683				 * the number of elements in the original
684				 * scatter list. Handle this correctly.
685				 */
686
687				if (j == bounce_sgl_count) {
688					/*
689					 * We are done; cleanup and return.
690					 */
691					kunmap_atomic((void *)(dest_addr -
692						cur_dest_sgl->offset));
693					local_irq_restore(flags);
694					return total_copied;
695				}
696
697				/* if we need to use another bounce buffer */
698				if (destlen || i != orig_sgl_count - 1) {
699					cur_src_sgl = sg_next(cur_src_sgl);
700					bounce_addr = (unsigned long)
701							kmap_atomic(
702							sg_page(cur_src_sgl));
703				}
704			} else if (destlen == 0 && i == orig_sgl_count - 1) {
705				/* unmap the last bounce that is < PAGE_SIZE */
706				kunmap_atomic((void *)bounce_addr);
707			}
708		}
709
710		kunmap_atomic((void *)(dest_addr - cur_dest_sgl->offset));
711		cur_dest_sgl = sg_next(cur_dest_sgl);
712	}
713
714	local_irq_restore(flags);
715
716	return total_copied;
717}
718
719/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
720static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
721					  struct scatterlist *bounce_sgl,
722					  unsigned int orig_sgl_count)
723{
724	int i;
725	int j = 0;
726	unsigned long src, dest;
727	unsigned int srclen, destlen, copylen;
728	unsigned int total_copied = 0;
729	unsigned long bounce_addr = 0;
730	unsigned long src_addr = 0;
731	unsigned long flags;
732	struct scatterlist *cur_src_sgl;
733	struct scatterlist *cur_dest_sgl;
734
735	local_irq_save(flags);
736
737	cur_src_sgl = orig_sgl;
738	cur_dest_sgl = bounce_sgl;
739
740	for (i = 0; i < orig_sgl_count; i++) {
741		src_addr = (unsigned long)
742				kmap_atomic(sg_page(cur_src_sgl)) +
743				cur_src_sgl->offset;
744		src = src_addr;
745		srclen = cur_src_sgl->length;
746
747		if (bounce_addr == 0)
748			bounce_addr = (unsigned long)
749					kmap_atomic(sg_page(cur_dest_sgl));
750
751		while (srclen) {
752			/* assume bounce offset always == 0 */
753			dest = bounce_addr + cur_dest_sgl->length;
754			destlen = PAGE_SIZE - cur_dest_sgl->length;
755
756			copylen = min(srclen, destlen);
757			memcpy((void *)dest, (void *)src, copylen);
758
759			total_copied += copylen;
760			cur_dest_sgl->length += copylen;
761			srclen -= copylen;
762			src += copylen;
763
764			if (cur_dest_sgl->length == PAGE_SIZE) {
765				/* full..move to next entry */
766				kunmap_atomic((void *)bounce_addr);
767				bounce_addr = 0;
768				j++;
769			}
770
771			/* if we need to use another bounce buffer */
772			if (srclen && bounce_addr == 0) {
773				cur_dest_sgl = sg_next(cur_dest_sgl);
774				bounce_addr = (unsigned long)
775						kmap_atomic(
776						sg_page(cur_dest_sgl));
777			}
778
779		}
780
781		kunmap_atomic((void *)(src_addr - cur_src_sgl->offset));
782		cur_src_sgl = sg_next(cur_src_sgl);
783	}
784
785	if (bounce_addr)
786		kunmap_atomic((void *)bounce_addr);
787
788	local_irq_restore(flags);
789
790	return total_copied;
791}
792
793static void handle_sc_creation(struct vmbus_channel *new_sc)
794{
795	struct hv_device *device = new_sc->primary_channel->device_obj;
796	struct storvsc_device *stor_device;
797	struct vmstorage_channel_properties props;
798
799	stor_device = get_out_stor_device(device);
800	if (!stor_device)
801		return;
802
803	if (stor_device->open_sub_channel == false)
804		return;
805
806	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
807
808	vmbus_open(new_sc,
809		   storvsc_ringbuffer_size,
810		   storvsc_ringbuffer_size,
811		   (void *)&props,
812		   sizeof(struct vmstorage_channel_properties),
813		   storvsc_on_channel_callback, new_sc);
814}
815
816static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
817{
818	struct storvsc_device *stor_device;
819	int num_cpus = num_online_cpus();
820	int num_sc;
821	struct storvsc_cmd_request *request;
822	struct vstor_packet *vstor_packet;
823	int ret, t;
824
825	num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
826	stor_device = get_out_stor_device(device);
827	if (!stor_device)
828		return;
829
830	request = &stor_device->init_request;
831	vstor_packet = &request->vstor_packet;
832
833	stor_device->open_sub_channel = true;
834	/*
835	 * Establish a handler for dealing with subchannels.
836	 */
837	vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
838
839	/*
840	 * Check to see if sub-channels have already been created. This
841	 * can happen when this driver is re-loaded after unloading.
842	 */
843
844	if (vmbus_are_subchannels_present(device->channel))
845		return;
846
847	stor_device->open_sub_channel = false;
848	/*
849	 * Request the host to create sub-channels.
850	 */
851	memset(request, 0, sizeof(struct storvsc_cmd_request));
852	init_completion(&request->wait_event);
853	vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
854	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
855	vstor_packet->sub_channel_count = num_sc;
856
857	ret = vmbus_sendpacket(device->channel, vstor_packet,
858			       (sizeof(struct vstor_packet) -
859			       vmscsi_size_delta),
860			       (unsigned long)request,
861			       VM_PKT_DATA_INBAND,
862			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
863
864	if (ret != 0)
865		return;
866
867	t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
868	if (t == 0)
869		return;
870
871	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
872	    vstor_packet->status != 0)
873		return;
874
875	/*
876	 * Now that we created the sub-channels, invoke the check; this
877	 * may trigger the callback.
878	 */
879	stor_device->open_sub_channel = true;
880	vmbus_are_subchannels_present(device->channel);
881}
882
883static int storvsc_channel_init(struct hv_device *device)
884{
885	struct storvsc_device *stor_device;
886	struct storvsc_cmd_request *request;
887	struct vstor_packet *vstor_packet;
888	int ret, t;
889	int max_chns;
890	bool process_sub_channels = false;
891
892	stor_device = get_out_stor_device(device);
893	if (!stor_device)
894		return -ENODEV;
895
896	request = &stor_device->init_request;
897	vstor_packet = &request->vstor_packet;
898
899	/*
900	 * Now, initiate the vsc/vsp initialization protocol on the open
901	 * channel
902	 */
903	memset(request, 0, sizeof(struct storvsc_cmd_request));
904	init_completion(&request->wait_event);
905	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
906	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
907
908	ret = vmbus_sendpacket(device->channel, vstor_packet,
909			       (sizeof(struct vstor_packet) -
910			       vmscsi_size_delta),
911			       (unsigned long)request,
912			       VM_PKT_DATA_INBAND,
913			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
914	if (ret != 0)
915		goto cleanup;
916
917	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
918	if (t == 0) {
919		ret = -ETIMEDOUT;
920		goto cleanup;
921	}
922
923	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
924	    vstor_packet->status != 0)
925		goto cleanup;
926
927
928	/* reuse the packet for version range supported */
929	memset(vstor_packet, 0, sizeof(struct vstor_packet));
930	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
931	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
932
933	vstor_packet->version.major_minor =
934		storvsc_get_version(vmstor_current_major, vmstor_current_minor);
935
936	/*
937	 * The revision number is only used in Windows; set it to 0.
938	 */
939	vstor_packet->version.revision = 0;
940
941	ret = vmbus_sendpacket(device->channel, vstor_packet,
942			       (sizeof(struct vstor_packet) -
943				vmscsi_size_delta),
944			       (unsigned long)request,
945			       VM_PKT_DATA_INBAND,
946			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
947	if (ret != 0)
948		goto cleanup;
949
950	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
951	if (t == 0) {
952		ret = -ETIMEDOUT;
953		goto cleanup;
954	}
955
956	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
957	    vstor_packet->status != 0)
958		goto cleanup;
959
960
961	memset(vstor_packet, 0, sizeof(struct vstor_packet));
962	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
963	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
964
965	ret = vmbus_sendpacket(device->channel, vstor_packet,
966			       (sizeof(struct vstor_packet) -
967				vmscsi_size_delta),
968			       (unsigned long)request,
969			       VM_PKT_DATA_INBAND,
970			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
971
972	if (ret != 0)
973		goto cleanup;
974
975	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
976	if (t == 0) {
977		ret = -ETIMEDOUT;
978		goto cleanup;
979	}
980
981	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
982	    vstor_packet->status != 0)
983		goto cleanup;
984
985	/*
986	 * Check to see if multi-channel support is there.
987	 * Hosts that implement protocol version of 5.1 and above
988	 * support multi-channel.
989	 */
990	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
991	if ((vmbus_proto_version != VERSION_WIN7) &&
992	   (vmbus_proto_version != VERSION_WS2008))  {
993		if (vstor_packet->storage_channel_properties.flags &
994		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
995			process_sub_channels = true;
996	}
997	stor_device->max_transfer_bytes =
998		vstor_packet->storage_channel_properties.max_transfer_bytes;
999
1000	memset(vstor_packet, 0, sizeof(struct vstor_packet));
1001	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
1002	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1003
1004	ret = vmbus_sendpacket(device->channel, vstor_packet,
1005			       (sizeof(struct vstor_packet) -
1006				vmscsi_size_delta),
1007			       (unsigned long)request,
1008			       VM_PKT_DATA_INBAND,
1009			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1010
1011	if (ret != 0)
1012		goto cleanup;
1013
1014	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1015	if (t == 0) {
1016		ret = -ETIMEDOUT;
1017		goto cleanup;
1018	}
1019
1020	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
1021	    vstor_packet->status != 0)
1022		goto cleanup;
1023
1024	if (process_sub_channels)
1025		handle_multichannel_storage(device, max_chns);
1026
1027
1028cleanup:
1029	return ret;
1030}
1031
1032static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1033				struct scsi_cmnd *scmnd,
1034				struct Scsi_Host *host,
1035				u8 asc, u8 ascq)
1036{
1037	struct storvsc_scan_work *wrk;
1038	void (*process_err_fn)(struct work_struct *work);
1039	bool do_work = false;
1040
1041	switch (vm_srb->srb_status) {
1042	case SRB_STATUS_ERROR:
1043		/*
1044		 * If there is an error; offline the device since all
1045		 * error recovery strategies would have already been
1046		 * deployed on the host side. However, if the command
1047		 * were a pass-through command deal with it appropriately.
1048		 */
1049		switch (scmnd->cmnd[0]) {
1050		case ATA_16:
1051		case ATA_12:
1052			set_host_byte(scmnd, DID_PASSTHROUGH);
1053			break;
1054		/*
1055		 * On Some Windows hosts TEST_UNIT_READY command can return
1056		 * SRB_STATUS_ERROR, let the upper level code deal with it
1057		 * based on the sense information.
1058		 */
1059		case TEST_UNIT_READY:
1060			break;
1061		default:
1062			set_host_byte(scmnd, DID_TARGET_FAILURE);
1063		}
1064		break;
1065	case SRB_STATUS_INVALID_LUN:
1066		do_work = true;
1067		process_err_fn = storvsc_remove_lun;
1068		break;
1069	case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
1070		if ((asc == 0x2a) && (ascq == 0x9)) {
1071			do_work = true;
1072			process_err_fn = storvsc_device_scan;
1073			/*
1074			 * Retry the I/O that trigerred this.
1075			 */
1076			set_host_byte(scmnd, DID_REQUEUE);
1077		}
1078		break;
1079	}
1080
1081	if (!do_work)
1082		return;
1083
1084	/*
1085	 * We need to schedule work to process this error; schedule it.
1086	 */
1087	wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1088	if (!wrk) {
1089		set_host_byte(scmnd, DID_TARGET_FAILURE);
1090		return;
1091	}
1092
1093	wrk->host = host;
1094	wrk->lun = vm_srb->lun;
1095	INIT_WORK(&wrk->work, process_err_fn);
1096	schedule_work(&wrk->work);
1097}
1098
1099
1100static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
1101{
1102	struct scsi_cmnd *scmnd = cmd_request->cmd;
1103	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1104	struct scsi_sense_hdr sense_hdr;
1105	struct vmscsi_request *vm_srb;
1106	struct Scsi_Host *host;
1107	struct storvsc_device *stor_dev;
1108	struct hv_device *dev = host_dev->dev;
1109	u32 payload_sz = cmd_request->payload_sz;
1110	void *payload = cmd_request->payload;
1111
1112	stor_dev = get_in_stor_device(dev);
1113	host = stor_dev->host;
1114
1115	vm_srb = &cmd_request->vstor_packet.vm_srb;
1116	if (cmd_request->bounce_sgl_count) {
1117		if (vm_srb->data_in == READ_TYPE)
1118			copy_from_bounce_buffer(scsi_sglist(scmnd),
1119					cmd_request->bounce_sgl,
1120					scsi_sg_count(scmnd),
1121					cmd_request->bounce_sgl_count);
1122		destroy_bounce_buffer(cmd_request->bounce_sgl,
1123					cmd_request->bounce_sgl_count);
1124	}
1125
1126	scmnd->result = vm_srb->scsi_status;
1127
1128	if (scmnd->result) {
1129		if (scsi_normalize_sense(scmnd->sense_buffer,
1130				SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1131			scsi_print_sense_hdr(scmnd->device, "storvsc",
1132					     &sense_hdr);
1133	}
1134
1135	if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
1136		storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1137					 sense_hdr.ascq);
1138
1139	scsi_set_resid(scmnd,
1140		cmd_request->payload->range.len -
1141		vm_srb->data_transfer_length);
1142
1143	scmnd->scsi_done(scmnd);
1144
1145	if (payload_sz >
1146		sizeof(struct vmbus_channel_packet_multipage_buffer))
1147		kfree(payload);
1148}
1149
1150static void storvsc_on_io_completion(struct hv_device *device,
1151				  struct vstor_packet *vstor_packet,
1152				  struct storvsc_cmd_request *request)
1153{
1154	struct storvsc_device *stor_device;
1155	struct vstor_packet *stor_pkt;
1156
1157	stor_device = hv_get_drvdata(device);
1158	stor_pkt = &request->vstor_packet;
1159
1160	/*
1161	 * The current SCSI handling on the host side does
1162	 * not correctly handle:
1163	 * INQUIRY command with page code parameter set to 0x80
1164	 * MODE_SENSE command with cmd[2] == 0x1c
1165	 *
1166	 * Setup srb and scsi status so this won't be fatal.
1167	 * We do this so we can distinguish truly fatal failues
1168	 * (srb status == 0x4) and off-line the device in that case.
1169	 */
1170
1171	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1172	   (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1173		vstor_packet->vm_srb.scsi_status = 0;
1174		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1175	}
1176
1177
1178	/* Copy over the status...etc */
1179	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1180	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1181	stor_pkt->vm_srb.sense_info_length =
1182	vstor_packet->vm_srb.sense_info_length;
1183
1184
1185	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1186		/* CHECK_CONDITION */
1187		if (vstor_packet->vm_srb.srb_status &
1188			SRB_STATUS_AUTOSENSE_VALID) {
1189			/* autosense data available */
1190
1191			memcpy(request->cmd->sense_buffer,
1192			       vstor_packet->vm_srb.sense_data,
1193			       vstor_packet->vm_srb.sense_info_length);
1194
1195		}
1196	}
1197
1198	stor_pkt->vm_srb.data_transfer_length =
1199	vstor_packet->vm_srb.data_transfer_length;
1200
1201	storvsc_command_completion(request);
1202
1203	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1204		stor_device->drain_notify)
1205		wake_up(&stor_device->waiting_to_drain);
1206
1207
1208}
1209
1210static void storvsc_on_receive(struct hv_device *device,
1211			     struct vstor_packet *vstor_packet,
1212			     struct storvsc_cmd_request *request)
1213{
1214	struct storvsc_scan_work *work;
1215	struct storvsc_device *stor_device;
1216
1217	switch (vstor_packet->operation) {
1218	case VSTOR_OPERATION_COMPLETE_IO:
1219		storvsc_on_io_completion(device, vstor_packet, request);
1220		break;
1221
1222	case VSTOR_OPERATION_REMOVE_DEVICE:
1223	case VSTOR_OPERATION_ENUMERATE_BUS:
1224		stor_device = get_in_stor_device(device);
1225		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1226		if (!work)
1227			return;
1228
1229		INIT_WORK(&work->work, storvsc_host_scan);
1230		work->host = stor_device->host;
1231		schedule_work(&work->work);
1232		break;
1233
1234	default:
1235		break;
1236	}
1237}
1238
1239static void storvsc_on_channel_callback(void *context)
1240{
1241	struct vmbus_channel *channel = (struct vmbus_channel *)context;
1242	struct hv_device *device;
1243	struct storvsc_device *stor_device;
1244	u32 bytes_recvd;
1245	u64 request_id;
1246	unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1247	struct storvsc_cmd_request *request;
1248	int ret;
1249
1250	if (channel->primary_channel != NULL)
1251		device = channel->primary_channel->device_obj;
1252	else
1253		device = channel->device_obj;
1254
1255	stor_device = get_in_stor_device(device);
1256	if (!stor_device)
1257		return;
1258
1259	do {
1260		ret = vmbus_recvpacket(channel, packet,
1261				       ALIGN((sizeof(struct vstor_packet) -
1262					     vmscsi_size_delta), 8),
1263				       &bytes_recvd, &request_id);
1264		if (ret == 0 && bytes_recvd > 0) {
1265
1266			request = (struct storvsc_cmd_request *)
1267					(unsigned long)request_id;
1268
1269			if ((request == &stor_device->init_request) ||
1270			    (request == &stor_device->reset_request)) {
1271
1272				memcpy(&request->vstor_packet, packet,
1273				       (sizeof(struct vstor_packet) -
1274					vmscsi_size_delta));
1275				complete(&request->wait_event);
1276			} else {
1277				storvsc_on_receive(device,
1278						(struct vstor_packet *)packet,
1279						request);
1280			}
1281		} else {
1282			break;
1283		}
1284	} while (1);
1285
1286	return;
1287}
1288
1289static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1290{
1291	struct vmstorage_channel_properties props;
1292	int ret;
1293
1294	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1295
1296	ret = vmbus_open(device->channel,
1297			 ring_size,
1298			 ring_size,
1299			 (void *)&props,
1300			 sizeof(struct vmstorage_channel_properties),
1301			 storvsc_on_channel_callback, device->channel);
1302
1303	if (ret != 0)
1304		return ret;
1305
1306	ret = storvsc_channel_init(device);
1307
1308	return ret;
1309}
1310
1311static int storvsc_dev_remove(struct hv_device *device)
1312{
1313	struct storvsc_device *stor_device;
1314	unsigned long flags;
1315
1316	stor_device = hv_get_drvdata(device);
1317
1318	spin_lock_irqsave(&device->channel->inbound_lock, flags);
1319	stor_device->destroy = true;
1320	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1321
1322	/*
1323	 * At this point, all outbound traffic should be disable. We
1324	 * only allow inbound traffic (responses) to proceed so that
1325	 * outstanding requests can be completed.
1326	 */
1327
1328	storvsc_wait_to_drain(stor_device);
1329
1330	/*
1331	 * Since we have already drained, we don't need to busy wait
1332	 * as was done in final_release_stor_device()
1333	 * Note that we cannot set the ext pointer to NULL until
1334	 * we have drained - to drain the outgoing packets, we need to
1335	 * allow incoming packets.
1336	 */
1337	spin_lock_irqsave(&device->channel->inbound_lock, flags);
1338	hv_set_drvdata(device, NULL);
1339	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1340
1341	/* Close the channel */
1342	vmbus_close(device->channel);
1343
1344	kfree(stor_device);
1345	return 0;
1346}
1347
1348static int storvsc_do_io(struct hv_device *device,
1349			 struct storvsc_cmd_request *request)
1350{
1351	struct storvsc_device *stor_device;
1352	struct vstor_packet *vstor_packet;
1353	struct vmbus_channel *outgoing_channel;
1354	int ret = 0;
1355
1356	vstor_packet = &request->vstor_packet;
1357	stor_device = get_out_stor_device(device);
1358
1359	if (!stor_device)
1360		return -ENODEV;
1361
1362
1363	request->device  = device;
1364	/*
1365	 * Select an an appropriate channel to send the request out.
1366	 */
1367
1368	outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1369
1370
1371	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1372
1373	vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1374					vmscsi_size_delta);
1375
1376
1377	vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1378
1379
1380	vstor_packet->vm_srb.data_transfer_length =
1381	request->payload->range.len;
1382
1383	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1384
1385	if (request->payload->range.len) {
1386
1387		ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1388				request->payload, request->payload_sz,
1389				vstor_packet,
1390				(sizeof(struct vstor_packet) -
1391				vmscsi_size_delta),
1392				(unsigned long)request);
1393	} else {
1394		ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1395			       (sizeof(struct vstor_packet) -
1396				vmscsi_size_delta),
1397			       (unsigned long)request,
1398			       VM_PKT_DATA_INBAND,
1399			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1400	}
1401
1402	if (ret != 0)
1403		return ret;
1404
1405	atomic_inc(&stor_device->num_outstanding_req);
1406
1407	return ret;
1408}
1409
1410static int storvsc_device_configure(struct scsi_device *sdevice)
1411{
1412
1413	blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1414
1415	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1416
1417	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1418
1419	sdevice->no_write_same = 1;
1420
1421	/*
1422	 * Add blist flags to permit the reading of the VPD pages even when
1423	 * the target may claim SPC-2 compliance. MSFT targets currently
1424	 * claim SPC-2 compliance while they implement post SPC-2 features.
1425	 * With this patch we can correctly handle WRITE_SAME_16 issues.
1426	 */
1427	sdevice->sdev_bflags |= msft_blist_flags;
1428
1429	/*
1430	 * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1431	 * if the device is a MSFT virtual device.
1432	 */
1433	if (!strncmp(sdevice->vendor, "Msft", 4)) {
1434		switch (vmbus_proto_version) {
1435		case VERSION_WIN8:
1436		case VERSION_WIN8_1:
1437			sdevice->scsi_level = SCSI_SPC_3;
1438			break;
1439		}
1440	}
1441
1442	return 0;
1443}
1444
1445static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1446			   sector_t capacity, int *info)
1447{
1448	sector_t nsect = capacity;
1449	sector_t cylinders = nsect;
1450	int heads, sectors_pt;
1451
1452	/*
1453	 * We are making up these values; let us keep it simple.
1454	 */
1455	heads = 0xff;
1456	sectors_pt = 0x3f;      /* Sectors per track */
1457	sector_div(cylinders, heads * sectors_pt);
1458	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1459		cylinders = 0xffff;
1460
1461	info[0] = heads;
1462	info[1] = sectors_pt;
1463	info[2] = (int)cylinders;
1464
1465	return 0;
1466}
1467
1468static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1469{
1470	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1471	struct hv_device *device = host_dev->dev;
1472
1473	struct storvsc_device *stor_device;
1474	struct storvsc_cmd_request *request;
1475	struct vstor_packet *vstor_packet;
1476	int ret, t;
1477
1478
1479	stor_device = get_out_stor_device(device);
1480	if (!stor_device)
1481		return FAILED;
1482
1483	request = &stor_device->reset_request;
1484	vstor_packet = &request->vstor_packet;
1485
1486	init_completion(&request->wait_event);
1487
1488	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1489	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1490	vstor_packet->vm_srb.path_id = stor_device->path_id;
1491
1492	ret = vmbus_sendpacket(device->channel, vstor_packet,
1493			       (sizeof(struct vstor_packet) -
1494				vmscsi_size_delta),
1495			       (unsigned long)&stor_device->reset_request,
1496			       VM_PKT_DATA_INBAND,
1497			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1498	if (ret != 0)
1499		return FAILED;
1500
1501	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1502	if (t == 0)
1503		return TIMEOUT_ERROR;
1504
1505
1506	/*
1507	 * At this point, all outstanding requests in the adapter
1508	 * should have been flushed out and return to us
1509	 * There is a potential race here where the host may be in
1510	 * the process of responding when we return from here.
1511	 * Just wait for all in-transit packets to be accounted for
1512	 * before we return from here.
1513	 */
1514	storvsc_wait_to_drain(stor_device);
1515
1516	return SUCCESS;
1517}
1518
1519/*
1520 * The host guarantees to respond to each command, although I/O latencies might
1521 * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1522 * chance to perform EH.
1523 */
1524static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1525{
1526	return BLK_EH_RESET_TIMER;
1527}
1528
1529static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1530{
1531	bool allowed = true;
1532	u8 scsi_op = scmnd->cmnd[0];
1533
1534	switch (scsi_op) {
1535	/* the host does not handle WRITE_SAME, log accident usage */
1536	case WRITE_SAME:
1537	/*
1538	 * smartd sends this command and the host does not handle
1539	 * this. So, don't send it.
1540	 */
1541	case SET_WINDOW:
1542		scmnd->result = ILLEGAL_REQUEST << 16;
1543		allowed = false;
1544		break;
1545	default:
1546		break;
1547	}
1548	return allowed;
1549}
1550
1551static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1552{
1553	int ret;
1554	struct hv_host_device *host_dev = shost_priv(host);
1555	struct hv_device *dev = host_dev->dev;
1556	struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1557	int i;
1558	struct scatterlist *sgl;
1559	unsigned int sg_count = 0;
1560	struct vmscsi_request *vm_srb;
1561	struct scatterlist *cur_sgl;
1562	struct vmbus_packet_mpb_array  *payload;
1563	u32 payload_sz;
1564	u32 length;
1565
1566	if (vmstor_current_major <= VMSTOR_WIN8_MAJOR) {
1567		/*
1568		 * On legacy hosts filter unimplemented commands.
1569		 * Future hosts are expected to correctly handle
1570		 * unsupported commands. Furthermore, it is
1571		 * possible that some of the currently
1572		 * unsupported commands maybe supported in
1573		 * future versions of the host.
1574		 */
1575		if (!storvsc_scsi_cmd_ok(scmnd)) {
1576			scmnd->scsi_done(scmnd);
1577			return 0;
1578		}
1579	}
1580
1581	/* Setup the cmd request */
1582	cmd_request->cmd = scmnd;
1583
1584	vm_srb = &cmd_request->vstor_packet.vm_srb;
1585	vm_srb->win8_extension.time_out_value = 60;
1586
1587	vm_srb->win8_extension.srb_flags |=
1588		(SRB_FLAGS_QUEUE_ACTION_ENABLE |
1589		SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
1590
1591	/* Build the SRB */
1592	switch (scmnd->sc_data_direction) {
1593	case DMA_TO_DEVICE:
1594		vm_srb->data_in = WRITE_TYPE;
1595		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1596		break;
1597	case DMA_FROM_DEVICE:
1598		vm_srb->data_in = READ_TYPE;
1599		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1600		break;
1601	default:
1602		vm_srb->data_in = UNKNOWN_TYPE;
1603		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1604		break;
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		/* check if we need to bounce the sgl */
1626		if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1627			cmd_request->bounce_sgl =
1628				create_bounce_buffer(sgl, sg_count,
1629						     length,
1630						     vm_srb->data_in);
1631			if (!cmd_request->bounce_sgl)
1632				return SCSI_MLQUEUE_HOST_BUSY;
1633
1634			cmd_request->bounce_sgl_count =
1635				ALIGN(length, PAGE_SIZE) >> PAGE_SHIFT;
1636
1637			if (vm_srb->data_in == WRITE_TYPE)
1638				copy_to_bounce_buffer(sgl,
1639					cmd_request->bounce_sgl, sg_count);
1640
1641			sgl = cmd_request->bounce_sgl;
1642			sg_count = cmd_request->bounce_sgl_count;
1643		}
1644
1645
1646		if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1647
1648			payload_sz = (sg_count * sizeof(void *) +
1649				      sizeof(struct vmbus_packet_mpb_array));
1650			payload = kmalloc(payload_sz, GFP_ATOMIC);
1651			if (!payload) {
1652				if (cmd_request->bounce_sgl_count)
1653					destroy_bounce_buffer(
1654					cmd_request->bounce_sgl,
1655					cmd_request->bounce_sgl_count);
1656
1657					return SCSI_MLQUEUE_DEVICE_BUSY;
1658			}
1659		}
1660
1661		payload->range.len = length;
1662		payload->range.offset = sgl[0].offset;
1663
1664		cur_sgl = sgl;
1665		for (i = 0; i < sg_count; i++) {
1666			payload->range.pfn_array[i] =
1667				page_to_pfn(sg_page((cur_sgl)));
1668			cur_sgl = sg_next(cur_sgl);
1669		}
1670
1671	} else if (scsi_sglist(scmnd)) {
1672		payload->range.len = length;
1673		payload->range.offset =
1674			virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1675		payload->range.pfn_array[0] =
1676			virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1677	}
1678
1679	cmd_request->payload = payload;
1680	cmd_request->payload_sz = payload_sz;
1681
1682	/* Invokes the vsc to start an IO */
1683	ret = storvsc_do_io(dev, cmd_request);
1684
1685	if (ret == -EAGAIN) {
1686		/* no more space */
1687
1688		if (cmd_request->bounce_sgl_count)
1689			destroy_bounce_buffer(cmd_request->bounce_sgl,
1690					cmd_request->bounce_sgl_count);
1691
1692		return SCSI_MLQUEUE_DEVICE_BUSY;
1693	}
1694
1695	return 0;
1696}
1697
1698static struct scsi_host_template scsi_driver = {
1699	.module	=		THIS_MODULE,
1700	.name =			"storvsc_host_t",
1701	.cmd_size =             sizeof(struct storvsc_cmd_request),
1702	.bios_param =		storvsc_get_chs,
1703	.queuecommand =		storvsc_queuecommand,
1704	.eh_host_reset_handler =	storvsc_host_reset_handler,
1705	.proc_name =		"storvsc_host",
1706	.eh_timed_out =		storvsc_eh_timed_out,
1707	.slave_configure =	storvsc_device_configure,
1708	.cmd_per_lun =		255,
1709	.this_id =		-1,
1710	.use_clustering =	ENABLE_CLUSTERING,
1711	/* Make sure we dont get a sg segment crosses a page boundary */
1712	.dma_boundary =		PAGE_SIZE-1,
1713	.no_write_same =	1,
1714};
1715
1716enum {
1717	SCSI_GUID,
1718	IDE_GUID,
1719	SFC_GUID,
1720};
1721
1722static const struct hv_vmbus_device_id id_table[] = {
1723	/* SCSI guid */
1724	{ HV_SCSI_GUID,
1725	  .driver_data = SCSI_GUID
1726	},
1727	/* IDE guid */
1728	{ HV_IDE_GUID,
1729	  .driver_data = IDE_GUID
1730	},
1731	/* Fibre Channel GUID */
1732	{
1733	  HV_SYNTHFC_GUID,
1734	  .driver_data = SFC_GUID
1735	},
1736	{ },
1737};
1738
1739MODULE_DEVICE_TABLE(vmbus, id_table);
1740
1741static int storvsc_probe(struct hv_device *device,
1742			const struct hv_vmbus_device_id *dev_id)
1743{
1744	int ret;
1745	int num_cpus = num_online_cpus();
1746	struct Scsi_Host *host;
1747	struct hv_host_device *host_dev;
1748	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1749	int target = 0;
1750	struct storvsc_device *stor_device;
1751	int max_luns_per_target;
1752	int max_targets;
1753	int max_channels;
1754	int max_sub_channels = 0;
1755
1756	/*
1757	 * Based on the windows host we are running on,
1758	 * set state to properly communicate with the host.
1759	 */
1760
1761	switch (vmbus_proto_version) {
1762	case VERSION_WS2008:
1763	case VERSION_WIN7:
1764		sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
1765		vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1766		vmstor_current_major = VMSTOR_WIN7_MAJOR;
1767		vmstor_current_minor = VMSTOR_WIN7_MINOR;
1768		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1769		max_targets = STORVSC_IDE_MAX_TARGETS;
1770		max_channels = STORVSC_IDE_MAX_CHANNELS;
1771		break;
1772	default:
1773		sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
1774		vmscsi_size_delta = 0;
1775		vmstor_current_major = VMSTOR_WIN8_MAJOR;
1776		vmstor_current_minor = VMSTOR_WIN8_MINOR;
1777		max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1778		max_targets = STORVSC_MAX_TARGETS;
1779		max_channels = STORVSC_MAX_CHANNELS;
1780		/*
1781		 * On Windows8 and above, we support sub-channels for storage.
1782		 * The number of sub-channels offerred is based on the number of
1783		 * VCPUs in the guest.
1784		 */
1785		max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1786		break;
1787	}
1788
1789	scsi_driver.can_queue = (max_outstanding_req_per_channel *
1790				 (max_sub_channels + 1));
1791
1792	host = scsi_host_alloc(&scsi_driver,
1793			       sizeof(struct hv_host_device));
1794	if (!host)
1795		return -ENOMEM;
1796
1797	host_dev = shost_priv(host);
1798	memset(host_dev, 0, sizeof(struct hv_host_device));
1799
1800	host_dev->port = host->host_no;
1801	host_dev->dev = device;
1802
1803
1804	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1805	if (!stor_device) {
1806		ret = -ENOMEM;
1807		goto err_out0;
1808	}
1809
1810	stor_device->destroy = false;
1811	stor_device->open_sub_channel = false;
1812	init_waitqueue_head(&stor_device->waiting_to_drain);
1813	stor_device->device = device;
1814	stor_device->host = host;
1815	hv_set_drvdata(device, stor_device);
1816
1817	stor_device->port_number = host->host_no;
1818	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1819	if (ret)
1820		goto err_out1;
1821
1822	host_dev->path = stor_device->path_id;
1823	host_dev->target = stor_device->target_id;
1824
1825	switch (dev_id->driver_data) {
1826	case SFC_GUID:
1827		host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1828		host->max_id = STORVSC_FC_MAX_TARGETS;
1829		host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1830		break;
1831
1832	case SCSI_GUID:
1833		host->max_lun = max_luns_per_target;
1834		host->max_id = max_targets;
1835		host->max_channel = max_channels - 1;
1836		break;
1837
1838	default:
1839		host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1840		host->max_id = STORVSC_IDE_MAX_TARGETS;
1841		host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1842		break;
1843	}
1844	/* max cmd length */
1845	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1846
1847	/*
1848	 * set the table size based on the info we got
1849	 * from the host.
1850	 */
1851	host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1852
1853	/* Register the HBA and start the scsi bus scan */
1854	ret = scsi_add_host(host, &device->device);
1855	if (ret != 0)
1856		goto err_out2;
1857
1858	if (!dev_is_ide) {
1859		scsi_scan_host(host);
1860	} else {
1861		target = (device->dev_instance.b[5] << 8 |
1862			 device->dev_instance.b[4]);
1863		ret = scsi_add_device(host, 0, target, 0);
1864		if (ret) {
1865			scsi_remove_host(host);
1866			goto err_out2;
1867		}
1868	}
1869	return 0;
1870
1871err_out2:
1872	/*
1873	 * Once we have connected with the host, we would need to
1874	 * to invoke storvsc_dev_remove() to rollback this state and
1875	 * this call also frees up the stor_device; hence the jump around
1876	 * err_out1 label.
1877	 */
1878	storvsc_dev_remove(device);
1879	goto err_out0;
1880
1881err_out1:
1882	kfree(stor_device);
1883
1884err_out0:
1885	scsi_host_put(host);
1886	return ret;
1887}
1888
1889static int storvsc_remove(struct hv_device *dev)
1890{
1891	struct storvsc_device *stor_device = hv_get_drvdata(dev);
1892	struct Scsi_Host *host = stor_device->host;
1893
1894	scsi_remove_host(host);
1895	storvsc_dev_remove(dev);
1896	scsi_host_put(host);
1897
1898	return 0;
1899}
1900
1901static struct hv_driver storvsc_drv = {
1902	.name = KBUILD_MODNAME,
1903	.id_table = id_table,
1904	.probe = storvsc_probe,
1905	.remove = storvsc_remove,
1906};
1907
1908static int __init storvsc_drv_init(void)
1909{
1910
1911	/*
1912	 * Divide the ring buffer data size (which is 1 page less
1913	 * than the ring buffer size since that page is reserved for
1914	 * the ring buffer indices) by the max request size (which is
1915	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1916	 */
1917	max_outstanding_req_per_channel =
1918		((storvsc_ringbuffer_size - PAGE_SIZE) /
1919		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1920		sizeof(struct vstor_packet) + sizeof(u64) -
1921		vmscsi_size_delta,
1922		sizeof(u64)));
1923
1924	return vmbus_driver_register(&storvsc_drv);
1925}
1926
1927static void __exit storvsc_drv_exit(void)
1928{
1929	vmbus_driver_unregister(&storvsc_drv);
1930}
1931
1932MODULE_LICENSE("GPL");
1933MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1934module_init(storvsc_drv_init);
1935module_exit(storvsc_drv_exit);
1936