2 * Copyright (c) 2009, Microsoft Corporation.
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.
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
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.
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
20 * K. Y. Srinivasan <kys@microsoft.com>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/device.h>
26 #include <linux/blkdev.h>
27 #include <linux/dmi.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_host.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_tcq.h>
33 #include <scsi/scsi_eh.h>
34 #include <scsi/scsi_devinfo.h>
35 #include <scsi/scsi_dbg.h>
38 #include "hyperv_storage.h"
40 static int storvsc_ringbuffer_size
= STORVSC_RING_BUFFER_SIZE
;
42 module_param(storvsc_ringbuffer_size
, int, S_IRUGO
);
43 MODULE_PARM_DESC(storvsc_ringbuffer_size
, "Ring buffer size (bytes)");
45 static const char *driver_name
= "storvsc";
47 /* {ba6163d9-04a1-4d29-b605-72e2ffb1dc7f} */
48 static const struct hv_guid stor_vsci_device_type
= {
50 0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
51 0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f
55 struct hv_host_device
{
56 struct hv_device
*dev
;
57 struct kmem_cache
*request_pool
;
63 struct storvsc_cmd_request
{
64 struct list_head entry
;
65 struct scsi_cmnd
*cmd
;
67 unsigned int bounce_sgl_count
;
68 struct scatterlist
*bounce_sgl
;
70 struct hv_storvsc_request request
;
74 static int storvsc_device_alloc(struct scsi_device
*sdevice
)
77 * This enables luns to be located sparsely. Otherwise, we may not
80 sdevice
->sdev_bflags
|= BLIST_SPARSELUN
| BLIST_LARGELUN
;
84 static int storvsc_merge_bvec(struct request_queue
*q
,
85 struct bvec_merge_data
*bmd
, struct bio_vec
*bvec
)
87 /* checking done by caller. */
91 static int storvsc_device_configure(struct scsi_device
*sdevice
)
93 scsi_adjust_queue_depth(sdevice
, MSG_SIMPLE_TAG
,
94 STORVSC_MAX_IO_REQUESTS
);
96 blk_queue_max_segment_size(sdevice
->request_queue
, PAGE_SIZE
);
98 blk_queue_merge_bvec(sdevice
->request_queue
, storvsc_merge_bvec
);
100 blk_queue_bounce_limit(sdevice
->request_queue
, BLK_BOUNCE_ANY
);
105 static void destroy_bounce_buffer(struct scatterlist
*sgl
,
106 unsigned int sg_count
)
109 struct page
*page_buf
;
111 for (i
= 0; i
< sg_count
; i
++) {
112 page_buf
= sg_page((&sgl
[i
]));
113 if (page_buf
!= NULL
)
114 __free_page(page_buf
);
120 static int do_bounce_buffer(struct scatterlist
*sgl
, unsigned int sg_count
)
124 /* No need to check */
128 /* We have at least 2 sg entries */
129 for (i
= 0; i
< sg_count
; i
++) {
131 /* make sure 1st one does not have hole */
132 if (sgl
[i
].offset
+ sgl
[i
].length
!= PAGE_SIZE
)
134 } else if (i
== sg_count
- 1) {
135 /* make sure last one does not have hole */
136 if (sgl
[i
].offset
!= 0)
139 /* make sure no hole in the middle */
140 if (sgl
[i
].length
!= PAGE_SIZE
|| sgl
[i
].offset
!= 0)
147 static struct scatterlist
*create_bounce_buffer(struct scatterlist
*sgl
,
148 unsigned int sg_count
,
153 struct scatterlist
*bounce_sgl
;
154 struct page
*page_buf
;
156 num_pages
= ALIGN(len
, PAGE_SIZE
) >> PAGE_SHIFT
;
158 bounce_sgl
= kcalloc(num_pages
, sizeof(struct scatterlist
), GFP_ATOMIC
);
162 for (i
= 0; i
< num_pages
; i
++) {
163 page_buf
= alloc_page(GFP_ATOMIC
);
166 sg_set_page(&bounce_sgl
[i
], page_buf
, 0, 0);
172 destroy_bounce_buffer(bounce_sgl
, num_pages
);
177 /* Assume the original sgl has enough room */
178 static unsigned int copy_from_bounce_buffer(struct scatterlist
*orig_sgl
,
179 struct scatterlist
*bounce_sgl
,
180 unsigned int orig_sgl_count
)
184 unsigned long src
, dest
;
185 unsigned int srclen
, destlen
, copylen
;
186 unsigned int total_copied
= 0;
187 unsigned long bounce_addr
= 0;
188 unsigned long dest_addr
= 0;
191 local_irq_save(flags
);
193 for (i
= 0; i
< orig_sgl_count
; i
++) {
194 dest_addr
= (unsigned long)kmap_atomic(sg_page((&orig_sgl
[i
])),
195 KM_IRQ0
) + orig_sgl
[i
].offset
;
197 destlen
= orig_sgl
[i
].length
;
199 if (bounce_addr
== 0)
201 (unsigned long)kmap_atomic(sg_page((&bounce_sgl
[j
])),
205 src
= bounce_addr
+ bounce_sgl
[j
].offset
;
206 srclen
= bounce_sgl
[j
].length
- bounce_sgl
[j
].offset
;
208 copylen
= min(srclen
, destlen
);
209 memcpy((void *)dest
, (void *)src
, copylen
);
211 total_copied
+= copylen
;
212 bounce_sgl
[j
].offset
+= copylen
;
216 if (bounce_sgl
[j
].offset
== bounce_sgl
[j
].length
) {
218 kunmap_atomic((void *)bounce_addr
, KM_IRQ0
);
221 /* if we need to use another bounce buffer */
222 if (destlen
|| i
!= orig_sgl_count
- 1)
224 (unsigned long)kmap_atomic(
225 sg_page((&bounce_sgl
[j
])), KM_IRQ0
);
226 } else if (destlen
== 0 && i
== orig_sgl_count
- 1) {
227 /* unmap the last bounce that is < PAGE_SIZE */
228 kunmap_atomic((void *)bounce_addr
, KM_IRQ0
);
232 kunmap_atomic((void *)(dest_addr
- orig_sgl
[i
].offset
),
236 local_irq_restore(flags
);
242 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
243 static unsigned int copy_to_bounce_buffer(struct scatterlist
*orig_sgl
,
244 struct scatterlist
*bounce_sgl
,
245 unsigned int orig_sgl_count
)
249 unsigned long src
, dest
;
250 unsigned int srclen
, destlen
, copylen
;
251 unsigned int total_copied
= 0;
252 unsigned long bounce_addr
= 0;
253 unsigned long src_addr
= 0;
256 local_irq_save(flags
);
258 for (i
= 0; i
< orig_sgl_count
; i
++) {
259 src_addr
= (unsigned long)kmap_atomic(sg_page((&orig_sgl
[i
])),
260 KM_IRQ0
) + orig_sgl
[i
].offset
;
262 srclen
= orig_sgl
[i
].length
;
264 if (bounce_addr
== 0)
266 (unsigned long)kmap_atomic(sg_page((&bounce_sgl
[j
])),
270 /* assume bounce offset always == 0 */
271 dest
= bounce_addr
+ bounce_sgl
[j
].length
;
272 destlen
= PAGE_SIZE
- bounce_sgl
[j
].length
;
274 copylen
= min(srclen
, destlen
);
275 memcpy((void *)dest
, (void *)src
, copylen
);
277 total_copied
+= copylen
;
278 bounce_sgl
[j
].length
+= copylen
;
282 if (bounce_sgl
[j
].length
== PAGE_SIZE
) {
283 /* full..move to next entry */
284 kunmap_atomic((void *)bounce_addr
, KM_IRQ0
);
287 /* if we need to use another bounce buffer */
288 if (srclen
|| i
!= orig_sgl_count
- 1)
290 (unsigned long)kmap_atomic(
291 sg_page((&bounce_sgl
[j
])), KM_IRQ0
);
293 } else if (srclen
== 0 && i
== orig_sgl_count
- 1) {
294 /* unmap the last bounce that is < PAGE_SIZE */
295 kunmap_atomic((void *)bounce_addr
, KM_IRQ0
);
299 kunmap_atomic((void *)(src_addr
- orig_sgl
[i
].offset
), KM_IRQ0
);
302 local_irq_restore(flags
);
308 static int storvsc_remove(struct hv_device
*dev
)
310 struct Scsi_Host
*host
= dev_get_drvdata(&dev
->device
);
311 struct hv_host_device
*host_dev
=
312 (struct hv_host_device
*)host
->hostdata
;
314 scsi_remove_host(host
);
318 storvsc_dev_remove(dev
);
319 if (host_dev
->request_pool
) {
320 kmem_cache_destroy(host_dev
->request_pool
);
321 host_dev
->request_pool
= NULL
;
327 static int storvsc_get_chs(struct scsi_device
*sdev
, struct block_device
* bdev
,
328 sector_t capacity
, int *info
)
330 sector_t nsect
= capacity
;
331 sector_t cylinders
= nsect
;
332 int heads
, sectors_pt
;
335 * We are making up these values; let us keep it simple.
338 sectors_pt
= 0x3f; /* Sectors per track */
339 sector_div(cylinders
, heads
* sectors_pt
);
340 if ((sector_t
)(cylinders
+ 1) * heads
* sectors_pt
< nsect
)
344 info
[1] = sectors_pt
;
345 info
[2] = (int)cylinders
;
350 static int storvsc_host_reset(struct hv_device
*device
)
352 struct storvsc_device
*stor_device
;
353 struct hv_storvsc_request
*request
;
354 struct vstor_packet
*vstor_packet
;
358 stor_device
= get_stor_device(device
);
362 request
= &stor_device
->reset_request
;
363 vstor_packet
= &request
->vstor_packet
;
365 init_completion(&request
->wait_event
);
367 vstor_packet
->operation
= VSTOR_OPERATION_RESET_BUS
;
368 vstor_packet
->flags
= REQUEST_COMPLETION_FLAG
;
369 vstor_packet
->vm_srb
.path_id
= stor_device
->path_id
;
371 ret
= vmbus_sendpacket(device
->channel
, vstor_packet
,
372 sizeof(struct vstor_packet
),
373 (unsigned long)&stor_device
->reset_request
,
375 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
);
379 t
= wait_for_completion_timeout(&request
->wait_event
, 5*HZ
);
387 * At this point, all outstanding requests in the adapter
388 * should have been flushed out and return to us
392 put_stor_device(device
);
398 * storvsc_host_reset_handler - Reset the scsi HBA
400 static int storvsc_host_reset_handler(struct scsi_cmnd
*scmnd
)
403 struct hv_host_device
*host_dev
=
404 (struct hv_host_device
*)scmnd
->device
->host
->hostdata
;
405 struct hv_device
*dev
= host_dev
->dev
;
407 ret
= storvsc_host_reset(dev
);
416 * storvsc_commmand_completion - Command completion processing
418 static void storvsc_commmand_completion(struct hv_storvsc_request
*request
)
420 struct storvsc_cmd_request
*cmd_request
=
421 (struct storvsc_cmd_request
*)request
->context
;
422 struct scsi_cmnd
*scmnd
= cmd_request
->cmd
;
423 struct hv_host_device
*host_dev
=
424 (struct hv_host_device
*)scmnd
->device
->host
->hostdata
;
425 void (*scsi_done_fn
)(struct scsi_cmnd
*);
426 struct scsi_sense_hdr sense_hdr
;
427 struct vmscsi_request
*vm_srb
;
429 if (cmd_request
->bounce_sgl_count
) {
431 /* FIXME: We can optimize on writes by just skipping this */
432 copy_from_bounce_buffer(scsi_sglist(scmnd
),
433 cmd_request
->bounce_sgl
,
434 scsi_sg_count(scmnd
));
435 destroy_bounce_buffer(cmd_request
->bounce_sgl
,
436 cmd_request
->bounce_sgl_count
);
439 vm_srb
= &request
->vstor_packet
.vm_srb
;
440 scmnd
->result
= vm_srb
->scsi_status
;
443 if (scsi_normalize_sense(scmnd
->sense_buffer
,
444 SCSI_SENSE_BUFFERSIZE
, &sense_hdr
))
445 scsi_print_sense_hdr("storvsc", &sense_hdr
);
448 scsi_set_resid(scmnd
,
449 request
->data_buffer
.len
-
450 vm_srb
->data_transfer_length
);
452 scsi_done_fn
= scmnd
->scsi_done
;
454 scmnd
->host_scribble
= NULL
;
455 scmnd
->scsi_done
= NULL
;
459 kmem_cache_free(host_dev
->request_pool
, cmd_request
);
464 * storvsc_queuecommand - Initiate command processing
466 static int storvsc_queuecommand_lck(struct scsi_cmnd
*scmnd
,
467 void (*done
)(struct scsi_cmnd
*))
470 struct hv_host_device
*host_dev
=
471 (struct hv_host_device
*)scmnd
->device
->host
->hostdata
;
472 struct hv_device
*dev
= host_dev
->dev
;
473 struct hv_storvsc_request
*request
;
474 struct storvsc_cmd_request
*cmd_request
;
475 unsigned int request_size
= 0;
477 struct scatterlist
*sgl
;
478 unsigned int sg_count
= 0;
479 struct vmscsi_request
*vm_srb
;
482 /* If retrying, no need to prep the cmd */
483 if (scmnd
->host_scribble
) {
486 (struct storvsc_cmd_request
*)scmnd
->host_scribble
;
491 scmnd
->scsi_done
= done
;
493 request_size
= sizeof(struct storvsc_cmd_request
);
495 cmd_request
= kmem_cache_zalloc(host_dev
->request_pool
,
498 scmnd
->scsi_done
= NULL
;
499 return SCSI_MLQUEUE_DEVICE_BUSY
;
502 /* Setup the cmd request */
503 cmd_request
->bounce_sgl_count
= 0;
504 cmd_request
->bounce_sgl
= NULL
;
505 cmd_request
->cmd
= scmnd
;
507 scmnd
->host_scribble
= (unsigned char *)cmd_request
;
509 request
= &cmd_request
->request
;
510 vm_srb
= &request
->vstor_packet
.vm_srb
;
514 switch (scmnd
->sc_data_direction
) {
516 vm_srb
->data_in
= WRITE_TYPE
;
518 case DMA_FROM_DEVICE
:
519 vm_srb
->data_in
= READ_TYPE
;
522 vm_srb
->data_in
= UNKNOWN_TYPE
;
526 request
->on_io_completion
= storvsc_commmand_completion
;
527 request
->context
= cmd_request
;/* scmnd; */
529 vm_srb
->port_number
= host_dev
->port
;
530 vm_srb
->path_id
= scmnd
->device
->channel
;
531 vm_srb
->target_id
= scmnd
->device
->id
;
532 vm_srb
->lun
= scmnd
->device
->lun
;
534 vm_srb
->cdb_length
= scmnd
->cmd_len
;
536 memcpy(vm_srb
->cdb
, scmnd
->cmnd
, vm_srb
->cdb_length
);
538 request
->sense_buffer
= scmnd
->sense_buffer
;
541 request
->data_buffer
.len
= scsi_bufflen(scmnd
);
542 if (scsi_sg_count(scmnd
)) {
543 sgl
= (struct scatterlist
*)scsi_sglist(scmnd
);
544 sg_count
= scsi_sg_count(scmnd
);
546 /* check if we need to bounce the sgl */
547 if (do_bounce_buffer(sgl
, scsi_sg_count(scmnd
)) != -1) {
548 cmd_request
->bounce_sgl
=
549 create_bounce_buffer(sgl
, scsi_sg_count(scmnd
),
550 scsi_bufflen(scmnd
));
551 if (!cmd_request
->bounce_sgl
) {
552 scmnd
->scsi_done
= NULL
;
553 scmnd
->host_scribble
= NULL
;
554 kmem_cache_free(host_dev
->request_pool
,
557 return SCSI_MLQUEUE_HOST_BUSY
;
560 cmd_request
->bounce_sgl_count
=
561 ALIGN(scsi_bufflen(scmnd
), PAGE_SIZE
) >>
565 * FIXME: We can optimize on reads by just skipping
568 copy_to_bounce_buffer(sgl
, cmd_request
->bounce_sgl
,
569 scsi_sg_count(scmnd
));
571 sgl
= cmd_request
->bounce_sgl
;
572 sg_count
= cmd_request
->bounce_sgl_count
;
575 request
->data_buffer
.offset
= sgl
[0].offset
;
577 for (i
= 0; i
< sg_count
; i
++)
578 request
->data_buffer
.pfn_array
[i
] =
579 page_to_pfn(sg_page((&sgl
[i
])));
581 } else if (scsi_sglist(scmnd
)) {
582 request
->data_buffer
.offset
=
583 virt_to_phys(scsi_sglist(scmnd
)) & (PAGE_SIZE
-1);
584 request
->data_buffer
.pfn_array
[0] =
585 virt_to_phys(scsi_sglist(scmnd
)) >> PAGE_SHIFT
;
589 /* Invokes the vsc to start an IO */
590 ret
= storvsc_do_io(dev
, &cmd_request
->request
);
595 if (cmd_request
->bounce_sgl_count
) {
597 * FIXME: We can optimize on writes by just skipping
600 copy_from_bounce_buffer(scsi_sglist(scmnd
),
601 cmd_request
->bounce_sgl
,
602 scsi_sg_count(scmnd
));
603 destroy_bounce_buffer(cmd_request
->bounce_sgl
,
604 cmd_request
->bounce_sgl_count
);
607 kmem_cache_free(host_dev
->request_pool
, cmd_request
);
609 scmnd
->scsi_done
= NULL
;
610 scmnd
->host_scribble
= NULL
;
612 ret
= SCSI_MLQUEUE_DEVICE_BUSY
;
618 static DEF_SCSI_QCMD(storvsc_queuecommand
)
622 static struct scsi_host_template scsi_driver
= {
623 .module
= THIS_MODULE
,
624 .name
= "storvsc_host_t",
625 .bios_param
= storvsc_get_chs
,
626 .queuecommand
= storvsc_queuecommand
,
627 .eh_host_reset_handler
= storvsc_host_reset_handler
,
628 .slave_alloc
= storvsc_device_alloc
,
629 .slave_configure
= storvsc_device_configure
,
631 /* 64 max_queue * 1 target */
632 .can_queue
= STORVSC_MAX_IO_REQUESTS
*STORVSC_MAX_TARGETS
,
634 /* no use setting to 0 since ll_blk_rw reset it to 1 */
636 .sg_tablesize
= MAX_MULTIPAGE_BUFFER_COUNT
,
638 * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
639 * into 1 sg element. If set, we must limit the max_segment_size to
640 * PAGE_SIZE, otherwise we may get 1 sg element that represents
643 /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
644 .use_clustering
= ENABLE_CLUSTERING
,
645 /* Make sure we dont get a sg segment crosses a page boundary */
646 .dma_boundary
= PAGE_SIZE
-1,
651 * storvsc_probe - Add a new device for this driver
654 static int storvsc_probe(struct hv_device
*device
)
657 struct Scsi_Host
*host
;
658 struct hv_host_device
*host_dev
;
659 struct storvsc_device_info device_info
;
661 host
= scsi_host_alloc(&scsi_driver
,
662 sizeof(struct hv_host_device
));
666 dev_set_drvdata(&device
->device
, host
);
668 host_dev
= (struct hv_host_device
*)host
->hostdata
;
669 memset(host_dev
, 0, sizeof(struct hv_host_device
));
671 host_dev
->port
= host
->host_no
;
672 host_dev
->dev
= device
;
674 host_dev
->request_pool
=
675 kmem_cache_create(dev_name(&device
->device
),
676 sizeof(struct storvsc_cmd_request
), 0,
677 SLAB_HWCACHE_ALIGN
, NULL
);
679 if (!host_dev
->request_pool
) {
684 device_info
.port_number
= host
->host_no
;
685 device_info
.ring_buffer_size
= storvsc_ringbuffer_size
;
686 /* Call to the vsc driver to add the device */
687 ret
= storvsc_dev_add(device
, (void *)&device_info
);
690 kmem_cache_destroy(host_dev
->request_pool
);
695 host_dev
->path
= device_info
.path_id
;
696 host_dev
->target
= device_info
.target_id
;
698 /* max # of devices per target */
699 host
->max_lun
= STORVSC_MAX_LUNS_PER_TARGET
;
700 /* max # of targets per channel */
701 host
->max_id
= STORVSC_MAX_TARGETS
;
702 /* max # of channels */
703 host
->max_channel
= STORVSC_MAX_CHANNELS
- 1;
705 /* Register the HBA and start the scsi bus scan */
706 ret
= scsi_add_host(host
, &device
->device
);
709 storvsc_dev_remove(device
);
711 kmem_cache_destroy(host_dev
->request_pool
);
716 scsi_scan_host(host
);
720 /* The one and only one */
722 static struct hv_driver storvsc_drv
= {
723 .probe
= storvsc_probe
,
724 .remove
= storvsc_remove
,
728 * We use a DMI table to determine if we should autoload this driver This is
729 * needed by distro tools to determine if the hyperv drivers should be
730 * installed and/or configured. We don't do anything else with the table, but
731 * it needs to be present.
734 static const struct dmi_system_id __initconst
735 hv_stor_dmi_table
[] __maybe_unused
= {
739 DMI_MATCH(DMI_SYS_VENDOR
, "Microsoft Corporation"),
740 DMI_MATCH(DMI_PRODUCT_NAME
, "Virtual Machine"),
741 DMI_MATCH(DMI_BOARD_NAME
, "Virtual Machine"),
746 MODULE_DEVICE_TABLE(dmi
, hv_stor_dmi_table
);
748 static int __init
storvsc_drv_init(void)
751 struct hv_driver
*drv
= &storvsc_drv
;
752 u32 max_outstanding_req_per_channel
;
755 * Divide the ring buffer data size (which is 1 page less
756 * than the ring buffer size since that page is reserved for
757 * the ring buffer indices) by the max request size (which is
758 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
761 max_outstanding_req_per_channel
=
762 ((storvsc_ringbuffer_size
- PAGE_SIZE
) /
763 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET
+
764 sizeof(struct vstor_packet
) + sizeof(u64
),
767 memcpy(&drv
->dev_type
, &stor_vsci_device_type
,
768 sizeof(struct hv_guid
));
770 if (max_outstanding_req_per_channel
<
771 STORVSC_MAX_IO_REQUESTS
)
774 drv
->driver
.name
= driver_name
;
777 /* The driver belongs to vmbus */
778 ret
= vmbus_child_driver_register(&drv
->driver
);
783 static void __exit
storvsc_drv_exit(void)
785 vmbus_child_driver_unregister(&storvsc_drv
.driver
);
788 MODULE_LICENSE("GPL");
789 MODULE_VERSION(HV_DRV_VERSION
);
790 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
791 module_init(storvsc_drv_init
);
792 module_exit(storvsc_drv_exit
);