Loading...
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/mempool.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 */
59
60#define VMSTOR_CURRENT_MAJOR 4
61#define VMSTOR_CURRENT_MINOR 2
62
63
64/* Packet structure describing virtual storage requests. */
65enum vstor_packet_operation {
66 VSTOR_OPERATION_COMPLETE_IO = 1,
67 VSTOR_OPERATION_REMOVE_DEVICE = 2,
68 VSTOR_OPERATION_EXECUTE_SRB = 3,
69 VSTOR_OPERATION_RESET_LUN = 4,
70 VSTOR_OPERATION_RESET_ADAPTER = 5,
71 VSTOR_OPERATION_RESET_BUS = 6,
72 VSTOR_OPERATION_BEGIN_INITIALIZATION = 7,
73 VSTOR_OPERATION_END_INITIALIZATION = 8,
74 VSTOR_OPERATION_QUERY_PROTOCOL_VERSION = 9,
75 VSTOR_OPERATION_QUERY_PROPERTIES = 10,
76 VSTOR_OPERATION_ENUMERATE_BUS = 11,
77 VSTOR_OPERATION_MAXIMUM = 11
78};
79
80/*
81 * Platform neutral description of a scsi request -
82 * this remains the same across the write regardless of 32/64 bit
83 * note: it's patterned off the SCSI_PASS_THROUGH structure
84 */
85#define STORVSC_MAX_CMD_LEN 0x10
86#define STORVSC_SENSE_BUFFER_SIZE 0x12
87#define STORVSC_MAX_BUF_LEN_WITH_PADDING 0x14
88
89struct vmscsi_request {
90 u16 length;
91 u8 srb_status;
92 u8 scsi_status;
93
94 u8 port_number;
95 u8 path_id;
96 u8 target_id;
97 u8 lun;
98
99 u8 cdb_length;
100 u8 sense_info_length;
101 u8 data_in;
102 u8 reserved;
103
104 u32 data_transfer_length;
105
106 union {
107 u8 cdb[STORVSC_MAX_CMD_LEN];
108 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
109 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
110 };
111} __attribute((packed));
112
113
114/*
115 * This structure is sent during the intialization phase to get the different
116 * properties of the channel.
117 */
118struct vmstorage_channel_properties {
119 u16 protocol_version;
120 u8 path_id;
121 u8 target_id;
122
123 /* Note: port number is only really known on the client side */
124 u32 port_number;
125 u32 flags;
126 u32 max_transfer_bytes;
127
128 /*
129 * This id is unique for each channel and will correspond with
130 * vendor specific data in the inquiry data.
131 */
132
133 u64 unique_id;
134} __packed;
135
136/* This structure is sent during the storage protocol negotiations. */
137struct vmstorage_protocol_version {
138 /* Major (MSW) and minor (LSW) version numbers. */
139 u16 major_minor;
140
141 /*
142 * Revision number is auto-incremented whenever this file is changed
143 * (See FILL_VMSTOR_REVISION macro above). Mismatch does not
144 * definitely indicate incompatibility--but it does indicate mismatched
145 * builds.
146 * This is only used on the windows side. Just set it to 0.
147 */
148 u16 revision;
149} __packed;
150
151/* Channel Property Flags */
152#define STORAGE_CHANNEL_REMOVABLE_FLAG 0x1
153#define STORAGE_CHANNEL_EMULATED_IDE_FLAG 0x2
154
155struct vstor_packet {
156 /* Requested operation type */
157 enum vstor_packet_operation operation;
158
159 /* Flags - see below for values */
160 u32 flags;
161
162 /* Status of the request returned from the server side. */
163 u32 status;
164
165 /* Data payload area */
166 union {
167 /*
168 * Structure used to forward SCSI commands from the
169 * client to the server.
170 */
171 struct vmscsi_request vm_srb;
172
173 /* Structure used to query channel properties. */
174 struct vmstorage_channel_properties storage_channel_properties;
175
176 /* Used during version negotiations. */
177 struct vmstorage_protocol_version version;
178 };
179} __packed;
180
181/*
182 * Packet Flags:
183 *
184 * This flag indicates that the server should send back a completion for this
185 * packet.
186 */
187
188#define REQUEST_COMPLETION_FLAG 0x1
189
190/* Matches Windows-end */
191enum storvsc_request_type {
192 WRITE_TYPE = 0,
193 READ_TYPE,
194 UNKNOWN_TYPE,
195};
196
197/*
198 * SRB status codes and masks; a subset of the codes used here.
199 */
200
201#define SRB_STATUS_AUTOSENSE_VALID 0x80
202#define SRB_STATUS_INVALID_LUN 0x20
203#define SRB_STATUS_SUCCESS 0x01
204#define SRB_STATUS_ERROR 0x04
205
206/*
207 * This is the end of Protocol specific defines.
208 */
209
210
211/*
212 * We setup a mempool to allocate request structures for this driver
213 * on a per-lun basis. The following define specifies the number of
214 * elements in the pool.
215 */
216
217#define STORVSC_MIN_BUF_NR 64
218static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
219
220module_param(storvsc_ringbuffer_size, int, S_IRUGO);
221MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
222
223#define STORVSC_MAX_IO_REQUESTS 128
224
225/*
226 * In Hyper-V, each port/path/target maps to 1 scsi host adapter. In
227 * reality, the path/target is not used (ie always set to 0) so our
228 * scsi host adapter essentially has 1 bus with 1 target that contains
229 * up to 256 luns.
230 */
231#define STORVSC_MAX_LUNS_PER_TARGET 64
232#define STORVSC_MAX_TARGETS 1
233#define STORVSC_MAX_CHANNELS 1
234
235
236
237struct storvsc_cmd_request {
238 struct list_head entry;
239 struct scsi_cmnd *cmd;
240
241 unsigned int bounce_sgl_count;
242 struct scatterlist *bounce_sgl;
243
244 struct hv_device *device;
245
246 /* Synchronize the request/response if needed */
247 struct completion wait_event;
248
249 unsigned char *sense_buffer;
250 struct hv_multipage_buffer data_buffer;
251 struct vstor_packet vstor_packet;
252};
253
254
255/* A storvsc device is a device object that contains a vmbus channel */
256struct storvsc_device {
257 struct hv_device *device;
258
259 bool destroy;
260 bool drain_notify;
261 atomic_t num_outstanding_req;
262 struct Scsi_Host *host;
263
264 wait_queue_head_t waiting_to_drain;
265
266 /*
267 * Each unique Port/Path/Target represents 1 channel ie scsi
268 * controller. In reality, the pathid, targetid is always 0
269 * and the port is set by us
270 */
271 unsigned int port_number;
272 unsigned char path_id;
273 unsigned char target_id;
274
275 /* Used for vsc/vsp channel reset process */
276 struct storvsc_cmd_request init_request;
277 struct storvsc_cmd_request reset_request;
278};
279
280struct stor_mem_pools {
281 struct kmem_cache *request_pool;
282 mempool_t *request_mempool;
283};
284
285struct hv_host_device {
286 struct hv_device *dev;
287 unsigned int port;
288 unsigned char path;
289 unsigned char target;
290};
291
292struct storvsc_scan_work {
293 struct work_struct work;
294 struct Scsi_Host *host;
295 uint lun;
296};
297
298static void storvsc_bus_scan(struct work_struct *work)
299{
300 struct storvsc_scan_work *wrk;
301 int id, order_id;
302
303 wrk = container_of(work, struct storvsc_scan_work, work);
304 for (id = 0; id < wrk->host->max_id; ++id) {
305 if (wrk->host->reverse_ordering)
306 order_id = wrk->host->max_id - id - 1;
307 else
308 order_id = id;
309
310 scsi_scan_target(&wrk->host->shost_gendev, 0,
311 order_id, SCAN_WILD_CARD, 1);
312 }
313 kfree(wrk);
314}
315
316static void storvsc_remove_lun(struct work_struct *work)
317{
318 struct storvsc_scan_work *wrk;
319 struct scsi_device *sdev;
320
321 wrk = container_of(work, struct storvsc_scan_work, work);
322 if (!scsi_host_get(wrk->host))
323 goto done;
324
325 sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
326
327 if (sdev) {
328 scsi_remove_device(sdev);
329 scsi_device_put(sdev);
330 }
331 scsi_host_put(wrk->host);
332
333done:
334 kfree(wrk);
335}
336
337/*
338 * Major/minor macros. Minor version is in LSB, meaning that earlier flat
339 * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
340 */
341
342static inline u16 storvsc_get_version(u8 major, u8 minor)
343{
344 u16 version;
345
346 version = ((major << 8) | minor);
347 return version;
348}
349
350/*
351 * We can get incoming messages from the host that are not in response to
352 * messages that we have sent out. An example of this would be messages
353 * received by the guest to notify dynamic addition/removal of LUNs. To
354 * deal with potential race conditions where the driver may be in the
355 * midst of being unloaded when we might receive an unsolicited message
356 * from the host, we have implemented a mechanism to gurantee sequential
357 * consistency:
358 *
359 * 1) Once the device is marked as being destroyed, we will fail all
360 * outgoing messages.
361 * 2) We permit incoming messages when the device is being destroyed,
362 * only to properly account for messages already sent out.
363 */
364
365static inline struct storvsc_device *get_out_stor_device(
366 struct hv_device *device)
367{
368 struct storvsc_device *stor_device;
369
370 stor_device = hv_get_drvdata(device);
371
372 if (stor_device && stor_device->destroy)
373 stor_device = NULL;
374
375 return stor_device;
376}
377
378
379static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
380{
381 dev->drain_notify = true;
382 wait_event(dev->waiting_to_drain,
383 atomic_read(&dev->num_outstanding_req) == 0);
384 dev->drain_notify = false;
385}
386
387static inline struct storvsc_device *get_in_stor_device(
388 struct hv_device *device)
389{
390 struct storvsc_device *stor_device;
391
392 stor_device = hv_get_drvdata(device);
393
394 if (!stor_device)
395 goto get_in_err;
396
397 /*
398 * If the device is being destroyed; allow incoming
399 * traffic only to cleanup outstanding requests.
400 */
401
402 if (stor_device->destroy &&
403 (atomic_read(&stor_device->num_outstanding_req) == 0))
404 stor_device = NULL;
405
406get_in_err:
407 return stor_device;
408
409}
410
411static void destroy_bounce_buffer(struct scatterlist *sgl,
412 unsigned int sg_count)
413{
414 int i;
415 struct page *page_buf;
416
417 for (i = 0; i < sg_count; i++) {
418 page_buf = sg_page((&sgl[i]));
419 if (page_buf != NULL)
420 __free_page(page_buf);
421 }
422
423 kfree(sgl);
424}
425
426static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
427{
428 int i;
429
430 /* No need to check */
431 if (sg_count < 2)
432 return -1;
433
434 /* We have at least 2 sg entries */
435 for (i = 0; i < sg_count; i++) {
436 if (i == 0) {
437 /* make sure 1st one does not have hole */
438 if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
439 return i;
440 } else if (i == sg_count - 1) {
441 /* make sure last one does not have hole */
442 if (sgl[i].offset != 0)
443 return i;
444 } else {
445 /* make sure no hole in the middle */
446 if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
447 return i;
448 }
449 }
450 return -1;
451}
452
453static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
454 unsigned int sg_count,
455 unsigned int len,
456 int write)
457{
458 int i;
459 int num_pages;
460 struct scatterlist *bounce_sgl;
461 struct page *page_buf;
462 unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
463
464 num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
465
466 bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
467 if (!bounce_sgl)
468 return NULL;
469
470 for (i = 0; i < num_pages; i++) {
471 page_buf = alloc_page(GFP_ATOMIC);
472 if (!page_buf)
473 goto cleanup;
474 sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
475 }
476
477 return bounce_sgl;
478
479cleanup:
480 destroy_bounce_buffer(bounce_sgl, num_pages);
481 return NULL;
482}
483
484/* Disgusting wrapper functions */
485static inline unsigned long sg_kmap_atomic(struct scatterlist *sgl, int idx)
486{
487 void *addr = kmap_atomic(sg_page(sgl + idx));
488 return (unsigned long)addr;
489}
490
491static inline void sg_kunmap_atomic(unsigned long addr)
492{
493 kunmap_atomic((void *)addr);
494}
495
496
497/* Assume the original sgl has enough room */
498static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
499 struct scatterlist *bounce_sgl,
500 unsigned int orig_sgl_count,
501 unsigned int bounce_sgl_count)
502{
503 int i;
504 int j = 0;
505 unsigned long src, dest;
506 unsigned int srclen, destlen, copylen;
507 unsigned int total_copied = 0;
508 unsigned long bounce_addr = 0;
509 unsigned long dest_addr = 0;
510 unsigned long flags;
511
512 local_irq_save(flags);
513
514 for (i = 0; i < orig_sgl_count; i++) {
515 dest_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
516 dest = dest_addr;
517 destlen = orig_sgl[i].length;
518
519 if (bounce_addr == 0)
520 bounce_addr = sg_kmap_atomic(bounce_sgl,j);
521
522 while (destlen) {
523 src = bounce_addr + bounce_sgl[j].offset;
524 srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
525
526 copylen = min(srclen, destlen);
527 memcpy((void *)dest, (void *)src, copylen);
528
529 total_copied += copylen;
530 bounce_sgl[j].offset += copylen;
531 destlen -= copylen;
532 dest += copylen;
533
534 if (bounce_sgl[j].offset == bounce_sgl[j].length) {
535 /* full */
536 sg_kunmap_atomic(bounce_addr);
537 j++;
538
539 /*
540 * It is possible that the number of elements
541 * in the bounce buffer may not be equal to
542 * the number of elements in the original
543 * scatter list. Handle this correctly.
544 */
545
546 if (j == bounce_sgl_count) {
547 /*
548 * We are done; cleanup and return.
549 */
550 sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
551 local_irq_restore(flags);
552 return total_copied;
553 }
554
555 /* if we need to use another bounce buffer */
556 if (destlen || i != orig_sgl_count - 1)
557 bounce_addr = sg_kmap_atomic(bounce_sgl,j);
558 } else if (destlen == 0 && i == orig_sgl_count - 1) {
559 /* unmap the last bounce that is < PAGE_SIZE */
560 sg_kunmap_atomic(bounce_addr);
561 }
562 }
563
564 sg_kunmap_atomic(dest_addr - orig_sgl[i].offset);
565 }
566
567 local_irq_restore(flags);
568
569 return total_copied;
570}
571
572/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
573static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
574 struct scatterlist *bounce_sgl,
575 unsigned int orig_sgl_count)
576{
577 int i;
578 int j = 0;
579 unsigned long src, dest;
580 unsigned int srclen, destlen, copylen;
581 unsigned int total_copied = 0;
582 unsigned long bounce_addr = 0;
583 unsigned long src_addr = 0;
584 unsigned long flags;
585
586 local_irq_save(flags);
587
588 for (i = 0; i < orig_sgl_count; i++) {
589 src_addr = sg_kmap_atomic(orig_sgl,i) + orig_sgl[i].offset;
590 src = src_addr;
591 srclen = orig_sgl[i].length;
592
593 if (bounce_addr == 0)
594 bounce_addr = sg_kmap_atomic(bounce_sgl,j);
595
596 while (srclen) {
597 /* assume bounce offset always == 0 */
598 dest = bounce_addr + bounce_sgl[j].length;
599 destlen = PAGE_SIZE - bounce_sgl[j].length;
600
601 copylen = min(srclen, destlen);
602 memcpy((void *)dest, (void *)src, copylen);
603
604 total_copied += copylen;
605 bounce_sgl[j].length += copylen;
606 srclen -= copylen;
607 src += copylen;
608
609 if (bounce_sgl[j].length == PAGE_SIZE) {
610 /* full..move to next entry */
611 sg_kunmap_atomic(bounce_addr);
612 j++;
613
614 /* if we need to use another bounce buffer */
615 if (srclen || i != orig_sgl_count - 1)
616 bounce_addr = sg_kmap_atomic(bounce_sgl,j);
617
618 } else if (srclen == 0 && i == orig_sgl_count - 1) {
619 /* unmap the last bounce that is < PAGE_SIZE */
620 sg_kunmap_atomic(bounce_addr);
621 }
622 }
623
624 sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
625 }
626
627 local_irq_restore(flags);
628
629 return total_copied;
630}
631
632static int storvsc_channel_init(struct hv_device *device)
633{
634 struct storvsc_device *stor_device;
635 struct storvsc_cmd_request *request;
636 struct vstor_packet *vstor_packet;
637 int ret, t;
638
639 stor_device = get_out_stor_device(device);
640 if (!stor_device)
641 return -ENODEV;
642
643 request = &stor_device->init_request;
644 vstor_packet = &request->vstor_packet;
645
646 /*
647 * Now, initiate the vsc/vsp initialization protocol on the open
648 * channel
649 */
650 memset(request, 0, sizeof(struct storvsc_cmd_request));
651 init_completion(&request->wait_event);
652 vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
653 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
654
655 ret = vmbus_sendpacket(device->channel, vstor_packet,
656 sizeof(struct vstor_packet),
657 (unsigned long)request,
658 VM_PKT_DATA_INBAND,
659 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
660 if (ret != 0)
661 goto cleanup;
662
663 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
664 if (t == 0) {
665 ret = -ETIMEDOUT;
666 goto cleanup;
667 }
668
669 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
670 vstor_packet->status != 0)
671 goto cleanup;
672
673
674 /* reuse the packet for version range supported */
675 memset(vstor_packet, 0, sizeof(struct vstor_packet));
676 vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
677 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
678
679 vstor_packet->version.major_minor =
680 storvsc_get_version(VMSTOR_CURRENT_MAJOR, VMSTOR_CURRENT_MINOR);
681
682 /*
683 * The revision number is only used in Windows; set it to 0.
684 */
685 vstor_packet->version.revision = 0;
686
687 ret = vmbus_sendpacket(device->channel, vstor_packet,
688 sizeof(struct vstor_packet),
689 (unsigned long)request,
690 VM_PKT_DATA_INBAND,
691 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
692 if (ret != 0)
693 goto cleanup;
694
695 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
696 if (t == 0) {
697 ret = -ETIMEDOUT;
698 goto cleanup;
699 }
700
701 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
702 vstor_packet->status != 0)
703 goto cleanup;
704
705
706 memset(vstor_packet, 0, sizeof(struct vstor_packet));
707 vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
708 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
709 vstor_packet->storage_channel_properties.port_number =
710 stor_device->port_number;
711
712 ret = vmbus_sendpacket(device->channel, vstor_packet,
713 sizeof(struct vstor_packet),
714 (unsigned long)request,
715 VM_PKT_DATA_INBAND,
716 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
717
718 if (ret != 0)
719 goto cleanup;
720
721 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
722 if (t == 0) {
723 ret = -ETIMEDOUT;
724 goto cleanup;
725 }
726
727 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
728 vstor_packet->status != 0)
729 goto cleanup;
730
731 stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
732 stor_device->target_id
733 = vstor_packet->storage_channel_properties.target_id;
734
735 memset(vstor_packet, 0, sizeof(struct vstor_packet));
736 vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
737 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
738
739 ret = vmbus_sendpacket(device->channel, vstor_packet,
740 sizeof(struct vstor_packet),
741 (unsigned long)request,
742 VM_PKT_DATA_INBAND,
743 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
744
745 if (ret != 0)
746 goto cleanup;
747
748 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
749 if (t == 0) {
750 ret = -ETIMEDOUT;
751 goto cleanup;
752 }
753
754 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
755 vstor_packet->status != 0)
756 goto cleanup;
757
758
759cleanup:
760 return ret;
761}
762
763
764static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
765{
766 struct scsi_cmnd *scmnd = cmd_request->cmd;
767 struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
768 void (*scsi_done_fn)(struct scsi_cmnd *);
769 struct scsi_sense_hdr sense_hdr;
770 struct vmscsi_request *vm_srb;
771 struct storvsc_scan_work *wrk;
772 struct stor_mem_pools *memp = scmnd->device->hostdata;
773
774 vm_srb = &cmd_request->vstor_packet.vm_srb;
775 if (cmd_request->bounce_sgl_count) {
776 if (vm_srb->data_in == READ_TYPE)
777 copy_from_bounce_buffer(scsi_sglist(scmnd),
778 cmd_request->bounce_sgl,
779 scsi_sg_count(scmnd),
780 cmd_request->bounce_sgl_count);
781 destroy_bounce_buffer(cmd_request->bounce_sgl,
782 cmd_request->bounce_sgl_count);
783 }
784
785 /*
786 * If there is an error; offline the device since all
787 * error recovery strategies would have already been
788 * deployed on the host side. However, if the command
789 * were a pass-through command deal with it appropriately.
790 */
791 scmnd->result = vm_srb->scsi_status;
792
793 if (vm_srb->srb_status == SRB_STATUS_ERROR) {
794 switch (scmnd->cmnd[0]) {
795 case ATA_16:
796 case ATA_12:
797 set_host_byte(scmnd, DID_PASSTHROUGH);
798 break;
799 default:
800 set_host_byte(scmnd, DID_TARGET_FAILURE);
801 }
802 }
803
804
805 /*
806 * If the LUN is invalid; remove the device.
807 */
808 if (vm_srb->srb_status == SRB_STATUS_INVALID_LUN) {
809 struct storvsc_device *stor_dev;
810 struct hv_device *dev = host_dev->dev;
811 struct Scsi_Host *host;
812
813 stor_dev = get_in_stor_device(dev);
814 host = stor_dev->host;
815
816 wrk = kmalloc(sizeof(struct storvsc_scan_work),
817 GFP_ATOMIC);
818 if (!wrk) {
819 scmnd->result = DID_TARGET_FAILURE << 16;
820 } else {
821 wrk->host = host;
822 wrk->lun = vm_srb->lun;
823 INIT_WORK(&wrk->work, storvsc_remove_lun);
824 schedule_work(&wrk->work);
825 }
826 }
827
828 if (scmnd->result) {
829 if (scsi_normalize_sense(scmnd->sense_buffer,
830 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
831 scsi_print_sense_hdr("storvsc", &sense_hdr);
832 }
833
834 scsi_set_resid(scmnd,
835 cmd_request->data_buffer.len -
836 vm_srb->data_transfer_length);
837
838 scsi_done_fn = scmnd->scsi_done;
839
840 scmnd->host_scribble = NULL;
841 scmnd->scsi_done = NULL;
842
843 scsi_done_fn(scmnd);
844
845 mempool_free(cmd_request, memp->request_mempool);
846}
847
848static void storvsc_on_io_completion(struct hv_device *device,
849 struct vstor_packet *vstor_packet,
850 struct storvsc_cmd_request *request)
851{
852 struct storvsc_device *stor_device;
853 struct vstor_packet *stor_pkt;
854
855 stor_device = hv_get_drvdata(device);
856 stor_pkt = &request->vstor_packet;
857
858 /*
859 * The current SCSI handling on the host side does
860 * not correctly handle:
861 * INQUIRY command with page code parameter set to 0x80
862 * MODE_SENSE command with cmd[2] == 0x1c
863 *
864 * Setup srb and scsi status so this won't be fatal.
865 * We do this so we can distinguish truly fatal failues
866 * (srb status == 0x4) and off-line the device in that case.
867 */
868
869 if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
870 (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
871 vstor_packet->vm_srb.scsi_status = 0;
872 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
873 }
874
875
876 /* Copy over the status...etc */
877 stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
878 stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
879 stor_pkt->vm_srb.sense_info_length =
880 vstor_packet->vm_srb.sense_info_length;
881
882 if (vstor_packet->vm_srb.scsi_status != 0 ||
883 vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS){
884 dev_warn(&device->device,
885 "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
886 stor_pkt->vm_srb.cdb[0],
887 vstor_packet->vm_srb.scsi_status,
888 vstor_packet->vm_srb.srb_status);
889 }
890
891 if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
892 /* CHECK_CONDITION */
893 if (vstor_packet->vm_srb.srb_status &
894 SRB_STATUS_AUTOSENSE_VALID) {
895 /* autosense data available */
896 dev_warn(&device->device,
897 "stor pkt %p autosense data valid - len %d\n",
898 request,
899 vstor_packet->vm_srb.sense_info_length);
900
901 memcpy(request->sense_buffer,
902 vstor_packet->vm_srb.sense_data,
903 vstor_packet->vm_srb.sense_info_length);
904
905 }
906 }
907
908 stor_pkt->vm_srb.data_transfer_length =
909 vstor_packet->vm_srb.data_transfer_length;
910
911 storvsc_command_completion(request);
912
913 if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
914 stor_device->drain_notify)
915 wake_up(&stor_device->waiting_to_drain);
916
917
918}
919
920static void storvsc_on_receive(struct hv_device *device,
921 struct vstor_packet *vstor_packet,
922 struct storvsc_cmd_request *request)
923{
924 struct storvsc_scan_work *work;
925 struct storvsc_device *stor_device;
926
927 switch (vstor_packet->operation) {
928 case VSTOR_OPERATION_COMPLETE_IO:
929 storvsc_on_io_completion(device, vstor_packet, request);
930 break;
931
932 case VSTOR_OPERATION_REMOVE_DEVICE:
933 case VSTOR_OPERATION_ENUMERATE_BUS:
934 stor_device = get_in_stor_device(device);
935 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
936 if (!work)
937 return;
938
939 INIT_WORK(&work->work, storvsc_bus_scan);
940 work->host = stor_device->host;
941 schedule_work(&work->work);
942 break;
943
944 default:
945 break;
946 }
947}
948
949static void storvsc_on_channel_callback(void *context)
950{
951 struct hv_device *device = (struct hv_device *)context;
952 struct storvsc_device *stor_device;
953 u32 bytes_recvd;
954 u64 request_id;
955 unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
956 struct storvsc_cmd_request *request;
957 int ret;
958
959
960 stor_device = get_in_stor_device(device);
961 if (!stor_device)
962 return;
963
964 do {
965 ret = vmbus_recvpacket(device->channel, packet,
966 ALIGN(sizeof(struct vstor_packet), 8),
967 &bytes_recvd, &request_id);
968 if (ret == 0 && bytes_recvd > 0) {
969
970 request = (struct storvsc_cmd_request *)
971 (unsigned long)request_id;
972
973 if ((request == &stor_device->init_request) ||
974 (request == &stor_device->reset_request)) {
975
976 memcpy(&request->vstor_packet, packet,
977 sizeof(struct vstor_packet));
978 complete(&request->wait_event);
979 } else {
980 storvsc_on_receive(device,
981 (struct vstor_packet *)packet,
982 request);
983 }
984 } else {
985 break;
986 }
987 } while (1);
988
989 return;
990}
991
992static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
993{
994 struct vmstorage_channel_properties props;
995 int ret;
996
997 memset(&props, 0, sizeof(struct vmstorage_channel_properties));
998
999 ret = vmbus_open(device->channel,
1000 ring_size,
1001 ring_size,
1002 (void *)&props,
1003 sizeof(struct vmstorage_channel_properties),
1004 storvsc_on_channel_callback, device);
1005
1006 if (ret != 0)
1007 return ret;
1008
1009 ret = storvsc_channel_init(device);
1010
1011 return ret;
1012}
1013
1014static int storvsc_dev_remove(struct hv_device *device)
1015{
1016 struct storvsc_device *stor_device;
1017 unsigned long flags;
1018
1019 stor_device = hv_get_drvdata(device);
1020
1021 spin_lock_irqsave(&device->channel->inbound_lock, flags);
1022 stor_device->destroy = true;
1023 spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1024
1025 /*
1026 * At this point, all outbound traffic should be disable. We
1027 * only allow inbound traffic (responses) to proceed so that
1028 * outstanding requests can be completed.
1029 */
1030
1031 storvsc_wait_to_drain(stor_device);
1032
1033 /*
1034 * Since we have already drained, we don't need to busy wait
1035 * as was done in final_release_stor_device()
1036 * Note that we cannot set the ext pointer to NULL until
1037 * we have drained - to drain the outgoing packets, we need to
1038 * allow incoming packets.
1039 */
1040 spin_lock_irqsave(&device->channel->inbound_lock, flags);
1041 hv_set_drvdata(device, NULL);
1042 spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1043
1044 /* Close the channel */
1045 vmbus_close(device->channel);
1046
1047 kfree(stor_device);
1048 return 0;
1049}
1050
1051static int storvsc_do_io(struct hv_device *device,
1052 struct storvsc_cmd_request *request)
1053{
1054 struct storvsc_device *stor_device;
1055 struct vstor_packet *vstor_packet;
1056 int ret = 0;
1057
1058 vstor_packet = &request->vstor_packet;
1059 stor_device = get_out_stor_device(device);
1060
1061 if (!stor_device)
1062 return -ENODEV;
1063
1064
1065 request->device = device;
1066
1067
1068 vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1069
1070 vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1071
1072
1073 vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1074
1075
1076 vstor_packet->vm_srb.data_transfer_length =
1077 request->data_buffer.len;
1078
1079 vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1080
1081 if (request->data_buffer.len) {
1082 ret = vmbus_sendpacket_multipagebuffer(device->channel,
1083 &request->data_buffer,
1084 vstor_packet,
1085 sizeof(struct vstor_packet),
1086 (unsigned long)request);
1087 } else {
1088 ret = vmbus_sendpacket(device->channel, vstor_packet,
1089 sizeof(struct vstor_packet),
1090 (unsigned long)request,
1091 VM_PKT_DATA_INBAND,
1092 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1093 }
1094
1095 if (ret != 0)
1096 return ret;
1097
1098 atomic_inc(&stor_device->num_outstanding_req);
1099
1100 return ret;
1101}
1102
1103static int storvsc_device_alloc(struct scsi_device *sdevice)
1104{
1105 struct stor_mem_pools *memp;
1106 int number = STORVSC_MIN_BUF_NR;
1107
1108 memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
1109 if (!memp)
1110 return -ENOMEM;
1111
1112 memp->request_pool =
1113 kmem_cache_create(dev_name(&sdevice->sdev_dev),
1114 sizeof(struct storvsc_cmd_request), 0,
1115 SLAB_HWCACHE_ALIGN, NULL);
1116
1117 if (!memp->request_pool)
1118 goto err0;
1119
1120 memp->request_mempool = mempool_create(number, mempool_alloc_slab,
1121 mempool_free_slab,
1122 memp->request_pool);
1123
1124 if (!memp->request_mempool)
1125 goto err1;
1126
1127 sdevice->hostdata = memp;
1128
1129 return 0;
1130
1131err1:
1132 kmem_cache_destroy(memp->request_pool);
1133
1134err0:
1135 kfree(memp);
1136 return -ENOMEM;
1137}
1138
1139static void storvsc_device_destroy(struct scsi_device *sdevice)
1140{
1141 struct stor_mem_pools *memp = sdevice->hostdata;
1142
1143 mempool_destroy(memp->request_mempool);
1144 kmem_cache_destroy(memp->request_pool);
1145 kfree(memp);
1146 sdevice->hostdata = NULL;
1147}
1148
1149static int storvsc_device_configure(struct scsi_device *sdevice)
1150{
1151 scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
1152 STORVSC_MAX_IO_REQUESTS);
1153
1154 blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1155
1156 blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1157
1158 return 0;
1159}
1160
1161static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1162 sector_t capacity, int *info)
1163{
1164 sector_t nsect = capacity;
1165 sector_t cylinders = nsect;
1166 int heads, sectors_pt;
1167
1168 /*
1169 * We are making up these values; let us keep it simple.
1170 */
1171 heads = 0xff;
1172 sectors_pt = 0x3f; /* Sectors per track */
1173 sector_div(cylinders, heads * sectors_pt);
1174 if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1175 cylinders = 0xffff;
1176
1177 info[0] = heads;
1178 info[1] = sectors_pt;
1179 info[2] = (int)cylinders;
1180
1181 return 0;
1182}
1183
1184static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1185{
1186 struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1187 struct hv_device *device = host_dev->dev;
1188
1189 struct storvsc_device *stor_device;
1190 struct storvsc_cmd_request *request;
1191 struct vstor_packet *vstor_packet;
1192 int ret, t;
1193
1194
1195 stor_device = get_out_stor_device(device);
1196 if (!stor_device)
1197 return FAILED;
1198
1199 request = &stor_device->reset_request;
1200 vstor_packet = &request->vstor_packet;
1201
1202 init_completion(&request->wait_event);
1203
1204 vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1205 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1206 vstor_packet->vm_srb.path_id = stor_device->path_id;
1207
1208 ret = vmbus_sendpacket(device->channel, vstor_packet,
1209 sizeof(struct vstor_packet),
1210 (unsigned long)&stor_device->reset_request,
1211 VM_PKT_DATA_INBAND,
1212 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1213 if (ret != 0)
1214 return FAILED;
1215
1216 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1217 if (t == 0)
1218 return TIMEOUT_ERROR;
1219
1220
1221 /*
1222 * At this point, all outstanding requests in the adapter
1223 * should have been flushed out and return to us
1224 */
1225
1226 return SUCCESS;
1227}
1228
1229static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1230{
1231 bool allowed = true;
1232 u8 scsi_op = scmnd->cmnd[0];
1233
1234 switch (scsi_op) {
1235 /*
1236 * smartd sends this command and the host does not handle
1237 * this. So, don't send it.
1238 */
1239 case SET_WINDOW:
1240 scmnd->result = ILLEGAL_REQUEST << 16;
1241 allowed = false;
1242 break;
1243 default:
1244 break;
1245 }
1246 return allowed;
1247}
1248
1249static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1250{
1251 int ret;
1252 struct hv_host_device *host_dev = shost_priv(host);
1253 struct hv_device *dev = host_dev->dev;
1254 struct storvsc_cmd_request *cmd_request;
1255 unsigned int request_size = 0;
1256 int i;
1257 struct scatterlist *sgl;
1258 unsigned int sg_count = 0;
1259 struct vmscsi_request *vm_srb;
1260 struct stor_mem_pools *memp = scmnd->device->hostdata;
1261
1262 if (!storvsc_scsi_cmd_ok(scmnd)) {
1263 scmnd->scsi_done(scmnd);
1264 return 0;
1265 }
1266
1267 request_size = sizeof(struct storvsc_cmd_request);
1268
1269 cmd_request = mempool_alloc(memp->request_mempool,
1270 GFP_ATOMIC);
1271
1272 /*
1273 * We might be invoked in an interrupt context; hence
1274 * mempool_alloc() can fail.
1275 */
1276 if (!cmd_request)
1277 return SCSI_MLQUEUE_DEVICE_BUSY;
1278
1279 memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
1280
1281 /* Setup the cmd request */
1282 cmd_request->cmd = scmnd;
1283
1284 scmnd->host_scribble = (unsigned char *)cmd_request;
1285
1286 vm_srb = &cmd_request->vstor_packet.vm_srb;
1287
1288
1289 /* Build the SRB */
1290 switch (scmnd->sc_data_direction) {
1291 case DMA_TO_DEVICE:
1292 vm_srb->data_in = WRITE_TYPE;
1293 break;
1294 case DMA_FROM_DEVICE:
1295 vm_srb->data_in = READ_TYPE;
1296 break;
1297 default:
1298 vm_srb->data_in = UNKNOWN_TYPE;
1299 break;
1300 }
1301
1302
1303 vm_srb->port_number = host_dev->port;
1304 vm_srb->path_id = scmnd->device->channel;
1305 vm_srb->target_id = scmnd->device->id;
1306 vm_srb->lun = scmnd->device->lun;
1307
1308 vm_srb->cdb_length = scmnd->cmd_len;
1309
1310 memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1311
1312 cmd_request->sense_buffer = scmnd->sense_buffer;
1313
1314
1315 cmd_request->data_buffer.len = scsi_bufflen(scmnd);
1316 if (scsi_sg_count(scmnd)) {
1317 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1318 sg_count = scsi_sg_count(scmnd);
1319
1320 /* check if we need to bounce the sgl */
1321 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
1322 cmd_request->bounce_sgl =
1323 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
1324 scsi_bufflen(scmnd),
1325 vm_srb->data_in);
1326 if (!cmd_request->bounce_sgl) {
1327 ret = SCSI_MLQUEUE_HOST_BUSY;
1328 goto queue_error;
1329 }
1330
1331 cmd_request->bounce_sgl_count =
1332 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
1333 PAGE_SHIFT;
1334
1335 if (vm_srb->data_in == WRITE_TYPE)
1336 copy_to_bounce_buffer(sgl,
1337 cmd_request->bounce_sgl,
1338 scsi_sg_count(scmnd));
1339
1340 sgl = cmd_request->bounce_sgl;
1341 sg_count = cmd_request->bounce_sgl_count;
1342 }
1343
1344 cmd_request->data_buffer.offset = sgl[0].offset;
1345
1346 for (i = 0; i < sg_count; i++)
1347 cmd_request->data_buffer.pfn_array[i] =
1348 page_to_pfn(sg_page((&sgl[i])));
1349
1350 } else if (scsi_sglist(scmnd)) {
1351 cmd_request->data_buffer.offset =
1352 virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1353 cmd_request->data_buffer.pfn_array[0] =
1354 virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1355 }
1356
1357 /* Invokes the vsc to start an IO */
1358 ret = storvsc_do_io(dev, cmd_request);
1359
1360 if (ret == -EAGAIN) {
1361 /* no more space */
1362
1363 if (cmd_request->bounce_sgl_count) {
1364 destroy_bounce_buffer(cmd_request->bounce_sgl,
1365 cmd_request->bounce_sgl_count);
1366
1367 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1368 goto queue_error;
1369 }
1370 }
1371
1372 return 0;
1373
1374queue_error:
1375 mempool_free(cmd_request, memp->request_mempool);
1376 scmnd->host_scribble = NULL;
1377 return ret;
1378}
1379
1380static struct scsi_host_template scsi_driver = {
1381 .module = THIS_MODULE,
1382 .name = "storvsc_host_t",
1383 .bios_param = storvsc_get_chs,
1384 .queuecommand = storvsc_queuecommand,
1385 .eh_host_reset_handler = storvsc_host_reset_handler,
1386 .slave_alloc = storvsc_device_alloc,
1387 .slave_destroy = storvsc_device_destroy,
1388 .slave_configure = storvsc_device_configure,
1389 .cmd_per_lun = 1,
1390 /* 64 max_queue * 1 target */
1391 .can_queue = STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
1392 .this_id = -1,
1393 /* no use setting to 0 since ll_blk_rw reset it to 1 */
1394 /* currently 32 */
1395 .sg_tablesize = MAX_MULTIPAGE_BUFFER_COUNT,
1396 .use_clustering = DISABLE_CLUSTERING,
1397 /* Make sure we dont get a sg segment crosses a page boundary */
1398 .dma_boundary = PAGE_SIZE-1,
1399};
1400
1401enum {
1402 SCSI_GUID,
1403 IDE_GUID,
1404};
1405
1406static const struct hv_vmbus_device_id id_table[] = {
1407 /* SCSI guid */
1408 { VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
1409 0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
1410 .driver_data = SCSI_GUID },
1411 /* IDE guid */
1412 { VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
1413 0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
1414 .driver_data = IDE_GUID },
1415 { },
1416};
1417
1418MODULE_DEVICE_TABLE(vmbus, id_table);
1419
1420static int storvsc_probe(struct hv_device *device,
1421 const struct hv_vmbus_device_id *dev_id)
1422{
1423 int ret;
1424 struct Scsi_Host *host;
1425 struct hv_host_device *host_dev;
1426 bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1427 int target = 0;
1428 struct storvsc_device *stor_device;
1429
1430 host = scsi_host_alloc(&scsi_driver,
1431 sizeof(struct hv_host_device));
1432 if (!host)
1433 return -ENOMEM;
1434
1435 host_dev = shost_priv(host);
1436 memset(host_dev, 0, sizeof(struct hv_host_device));
1437
1438 host_dev->port = host->host_no;
1439 host_dev->dev = device;
1440
1441
1442 stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1443 if (!stor_device) {
1444 ret = -ENOMEM;
1445 goto err_out0;
1446 }
1447
1448 stor_device->destroy = false;
1449 init_waitqueue_head(&stor_device->waiting_to_drain);
1450 stor_device->device = device;
1451 stor_device->host = host;
1452 hv_set_drvdata(device, stor_device);
1453
1454 stor_device->port_number = host->host_no;
1455 ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1456 if (ret)
1457 goto err_out1;
1458
1459 host_dev->path = stor_device->path_id;
1460 host_dev->target = stor_device->target_id;
1461
1462 /* max # of devices per target */
1463 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1464 /* max # of targets per channel */
1465 host->max_id = STORVSC_MAX_TARGETS;
1466 /* max # of channels */
1467 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1468 /* max cmd length */
1469 host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1470
1471 /* Register the HBA and start the scsi bus scan */
1472 ret = scsi_add_host(host, &device->device);
1473 if (ret != 0)
1474 goto err_out2;
1475
1476 if (!dev_is_ide) {
1477 scsi_scan_host(host);
1478 } else {
1479 target = (device->dev_instance.b[5] << 8 |
1480 device->dev_instance.b[4]);
1481 ret = scsi_add_device(host, 0, target, 0);
1482 if (ret) {
1483 scsi_remove_host(host);
1484 goto err_out2;
1485 }
1486 }
1487 return 0;
1488
1489err_out2:
1490 /*
1491 * Once we have connected with the host, we would need to
1492 * to invoke storvsc_dev_remove() to rollback this state and
1493 * this call also frees up the stor_device; hence the jump around
1494 * err_out1 label.
1495 */
1496 storvsc_dev_remove(device);
1497 goto err_out0;
1498
1499err_out1:
1500 kfree(stor_device);
1501
1502err_out0:
1503 scsi_host_put(host);
1504 return ret;
1505}
1506
1507static int storvsc_remove(struct hv_device *dev)
1508{
1509 struct storvsc_device *stor_device = hv_get_drvdata(dev);
1510 struct Scsi_Host *host = stor_device->host;
1511
1512 scsi_remove_host(host);
1513 storvsc_dev_remove(dev);
1514 scsi_host_put(host);
1515
1516 return 0;
1517}
1518
1519static struct hv_driver storvsc_drv = {
1520 .name = KBUILD_MODNAME,
1521 .id_table = id_table,
1522 .probe = storvsc_probe,
1523 .remove = storvsc_remove,
1524};
1525
1526static int __init storvsc_drv_init(void)
1527{
1528 u32 max_outstanding_req_per_channel;
1529
1530 /*
1531 * Divide the ring buffer data size (which is 1 page less
1532 * than the ring buffer size since that page is reserved for
1533 * the ring buffer indices) by the max request size (which is
1534 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1535 */
1536 max_outstanding_req_per_channel =
1537 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1538 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1539 sizeof(struct vstor_packet) + sizeof(u64),
1540 sizeof(u64)));
1541
1542 if (max_outstanding_req_per_channel <
1543 STORVSC_MAX_IO_REQUESTS)
1544 return -EINVAL;
1545
1546 return vmbus_driver_register(&storvsc_drv);
1547}
1548
1549static void __exit storvsc_drv_exit(void)
1550{
1551 vmbus_driver_unregister(&storvsc_drv);
1552}
1553
1554MODULE_LICENSE("GPL");
1555MODULE_VERSION(HV_DRV_VERSION);
1556MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1557module_init(storvsc_drv_init);
1558module_exit(storvsc_drv_exit);