2 * Virtio SCSI HBA driver
4 * Copyright IBM Corp. 2010
5 * Copyright Red Hat, Inc. 2011
8 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
9 * Paolo Bonzini <pbonzini@redhat.com>
11 * This work is licensed under the terms of the GNU GPL, version 2 or later.
12 * See the COPYING file in the top-level directory.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/mempool.h>
21 #include <linux/virtio.h>
22 #include <linux/virtio_ids.h>
23 #include <linux/virtio_config.h>
24 #include <linux/virtio_scsi.h>
25 #include <linux/cpu.h>
26 #include <scsi/scsi_host.h>
27 #include <scsi/scsi_device.h>
28 #include <scsi/scsi_cmnd.h>
30 #define VIRTIO_SCSI_MEMPOOL_SZ 64
31 #define VIRTIO_SCSI_EVENT_LEN 8
32 #define VIRTIO_SCSI_VQ_BASE 2
34 /* Command queue element */
35 struct virtio_scsi_cmd
{
37 struct completion
*comp
;
39 struct virtio_scsi_cmd_req cmd
;
40 struct virtio_scsi_ctrl_tmf_req tmf
;
41 struct virtio_scsi_ctrl_an_req an
;
44 struct virtio_scsi_cmd_resp cmd
;
45 struct virtio_scsi_ctrl_tmf_resp tmf
;
46 struct virtio_scsi_ctrl_an_resp an
;
47 struct virtio_scsi_event evt
;
49 } ____cacheline_aligned_in_smp
;
51 struct virtio_scsi_event_node
{
52 struct virtio_scsi
*vscsi
;
53 struct virtio_scsi_event event
;
54 struct work_struct work
;
57 struct virtio_scsi_vq
{
65 * Per-target queue state.
67 * This struct holds the data needed by the queue steering policy. When a
68 * target is sent multiple requests, we need to drive them to the same queue so
69 * that FIFO processing order is kept. However, if a target was idle, we can
70 * choose a queue arbitrarily. In this case the queue is chosen according to
71 * the current VCPU, so the driver expects the number of request queues to be
72 * equal to the number of VCPUs. This makes it easy and fast to select the
73 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues
74 * (each virtqueue's affinity is set to the CPU that "owns" the queue).
76 * An interesting effect of this policy is that only writes to req_vq need to
77 * take the tgt_lock. Read can be done outside the lock because:
79 * - writes of req_vq only occur when atomic_inc_return(&tgt->reqs) returns 1.
80 * In that case, no other CPU is reading req_vq: even if they were in
81 * virtscsi_queuecommand_multi, they would be spinning on tgt_lock.
83 * - reads of req_vq only occur when the target is not idle (reqs != 0).
84 * A CPU that enters virtscsi_queuecommand_multi will not modify req_vq.
86 * Similarly, decrements of reqs are never concurrent with writes of req_vq.
87 * Thus they can happen outside the tgt_lock, provided of course we make reqs
90 struct virtio_scsi_target_state
{
91 /* This spinlock never held at the same time as vq_lock. */
94 /* Count of outstanding requests. */
97 /* Currently active virtqueue for requests sent to this target. */
98 struct virtio_scsi_vq
*req_vq
;
101 /* Driver instance state */
103 struct virtio_device
*vdev
;
105 /* Get some buffers ready for event vq */
106 struct virtio_scsi_event_node event_list
[VIRTIO_SCSI_EVENT_LEN
];
110 /* If the affinity hint is set for virtqueues */
111 bool affinity_hint_set
;
113 /* CPU hotplug notifier */
114 struct notifier_block nb
;
116 struct virtio_scsi_vq ctrl_vq
;
117 struct virtio_scsi_vq event_vq
;
118 struct virtio_scsi_vq req_vqs
[];
121 static struct kmem_cache
*virtscsi_cmd_cache
;
122 static mempool_t
*virtscsi_cmd_pool
;
124 static inline struct Scsi_Host
*virtio_scsi_host(struct virtio_device
*vdev
)
129 static void virtscsi_compute_resid(struct scsi_cmnd
*sc
, u32 resid
)
134 if (!scsi_bidi_cmnd(sc
)) {
135 scsi_set_resid(sc
, resid
);
139 scsi_in(sc
)->resid
= min(resid
, scsi_in(sc
)->length
);
140 scsi_out(sc
)->resid
= resid
- scsi_in(sc
)->resid
;
144 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
146 * Called with vq_lock held.
148 static void virtscsi_complete_cmd(struct virtio_scsi
*vscsi
, void *buf
)
150 struct virtio_scsi_cmd
*cmd
= buf
;
151 struct scsi_cmnd
*sc
= cmd
->sc
;
152 struct virtio_scsi_cmd_resp
*resp
= &cmd
->resp
.cmd
;
153 struct virtio_scsi_target_state
*tgt
=
154 scsi_target(sc
->device
)->hostdata
;
156 dev_dbg(&sc
->device
->sdev_gendev
,
157 "cmd %p response %u status %#02x sense_len %u\n",
158 sc
, resp
->response
, resp
->status
, resp
->sense_len
);
160 sc
->result
= resp
->status
;
161 virtscsi_compute_resid(sc
, resp
->resid
);
162 switch (resp
->response
) {
163 case VIRTIO_SCSI_S_OK
:
164 set_host_byte(sc
, DID_OK
);
166 case VIRTIO_SCSI_S_OVERRUN
:
167 set_host_byte(sc
, DID_ERROR
);
169 case VIRTIO_SCSI_S_ABORTED
:
170 set_host_byte(sc
, DID_ABORT
);
172 case VIRTIO_SCSI_S_BAD_TARGET
:
173 set_host_byte(sc
, DID_BAD_TARGET
);
175 case VIRTIO_SCSI_S_RESET
:
176 set_host_byte(sc
, DID_RESET
);
178 case VIRTIO_SCSI_S_BUSY
:
179 set_host_byte(sc
, DID_BUS_BUSY
);
181 case VIRTIO_SCSI_S_TRANSPORT_FAILURE
:
182 set_host_byte(sc
, DID_TRANSPORT_DISRUPTED
);
184 case VIRTIO_SCSI_S_TARGET_FAILURE
:
185 set_host_byte(sc
, DID_TARGET_FAILURE
);
187 case VIRTIO_SCSI_S_NEXUS_FAILURE
:
188 set_host_byte(sc
, DID_NEXUS_FAILURE
);
191 scmd_printk(KERN_WARNING
, sc
, "Unknown response %d",
194 case VIRTIO_SCSI_S_FAILURE
:
195 set_host_byte(sc
, DID_ERROR
);
199 WARN_ON(resp
->sense_len
> VIRTIO_SCSI_SENSE_SIZE
);
200 if (sc
->sense_buffer
) {
201 memcpy(sc
->sense_buffer
, resp
->sense
,
202 min_t(u32
, resp
->sense_len
, VIRTIO_SCSI_SENSE_SIZE
));
204 set_driver_byte(sc
, DRIVER_SENSE
);
207 mempool_free(cmd
, virtscsi_cmd_pool
);
210 atomic_dec(&tgt
->reqs
);
213 static void virtscsi_vq_done(struct virtio_scsi
*vscsi
,
214 struct virtio_scsi_vq
*virtscsi_vq
,
215 void (*fn
)(struct virtio_scsi
*vscsi
, void *buf
))
220 struct virtqueue
*vq
= virtscsi_vq
->vq
;
222 spin_lock_irqsave(&virtscsi_vq
->vq_lock
, flags
);
224 virtqueue_disable_cb(vq
);
225 while ((buf
= virtqueue_get_buf(vq
, &len
)) != NULL
)
228 if (unlikely(virtqueue_is_broken(vq
)))
230 } while (!virtqueue_enable_cb(vq
));
231 spin_unlock_irqrestore(&virtscsi_vq
->vq_lock
, flags
);
234 static void virtscsi_req_done(struct virtqueue
*vq
)
236 struct Scsi_Host
*sh
= virtio_scsi_host(vq
->vdev
);
237 struct virtio_scsi
*vscsi
= shost_priv(sh
);
238 int index
= vq
->index
- VIRTIO_SCSI_VQ_BASE
;
239 struct virtio_scsi_vq
*req_vq
= &vscsi
->req_vqs
[index
];
242 * Read req_vq before decrementing the reqs field in
243 * virtscsi_complete_cmd.
247 * CPU #0 virtscsi_queuecommand_multi (CPU #1)
248 * ------------------------------------------------------------
251 * read reqs (reqs = 1)
252 * write reqs (reqs = 0)
253 * increment reqs (reqs = 1)
256 * Possible reordering without barriers:
258 * CPU #0 virtscsi_queuecommand_multi (CPU #1)
259 * ------------------------------------------------------------
261 * read reqs (reqs = 1)
262 * write reqs (reqs = 0)
263 * increment reqs (reqs = 1)
265 * read (wrong) req_vq
267 * We do not need a full smp_rmb, because req_vq is required to get
268 * to tgt->reqs: tgt is &vscsi->tgt[sc->device->id], where sc is stored
269 * in the virtqueue as the user token.
271 smp_read_barrier_depends();
273 virtscsi_vq_done(vscsi
, req_vq
, virtscsi_complete_cmd
);
276 static void virtscsi_complete_free(struct virtio_scsi
*vscsi
, void *buf
)
278 struct virtio_scsi_cmd
*cmd
= buf
;
281 complete_all(cmd
->comp
);
283 mempool_free(cmd
, virtscsi_cmd_pool
);
286 static void virtscsi_ctrl_done(struct virtqueue
*vq
)
288 struct Scsi_Host
*sh
= virtio_scsi_host(vq
->vdev
);
289 struct virtio_scsi
*vscsi
= shost_priv(sh
);
291 virtscsi_vq_done(vscsi
, &vscsi
->ctrl_vq
, virtscsi_complete_free
);
294 static int virtscsi_kick_event(struct virtio_scsi
*vscsi
,
295 struct virtio_scsi_event_node
*event_node
)
298 struct scatterlist sg
;
301 sg_init_one(&sg
, &event_node
->event
, sizeof(struct virtio_scsi_event
));
303 spin_lock_irqsave(&vscsi
->event_vq
.vq_lock
, flags
);
305 err
= virtqueue_add_inbuf(vscsi
->event_vq
.vq
, &sg
, 1, event_node
,
308 virtqueue_kick(vscsi
->event_vq
.vq
);
310 spin_unlock_irqrestore(&vscsi
->event_vq
.vq_lock
, flags
);
315 static int virtscsi_kick_event_all(struct virtio_scsi
*vscsi
)
319 for (i
= 0; i
< VIRTIO_SCSI_EVENT_LEN
; i
++) {
320 vscsi
->event_list
[i
].vscsi
= vscsi
;
321 virtscsi_kick_event(vscsi
, &vscsi
->event_list
[i
]);
327 static void virtscsi_cancel_event_work(struct virtio_scsi
*vscsi
)
331 for (i
= 0; i
< VIRTIO_SCSI_EVENT_LEN
; i
++)
332 cancel_work_sync(&vscsi
->event_list
[i
].work
);
335 static void virtscsi_handle_transport_reset(struct virtio_scsi
*vscsi
,
336 struct virtio_scsi_event
*event
)
338 struct scsi_device
*sdev
;
339 struct Scsi_Host
*shost
= virtio_scsi_host(vscsi
->vdev
);
340 unsigned int target
= event
->lun
[1];
341 unsigned int lun
= (event
->lun
[2] << 8) | event
->lun
[3];
343 switch (event
->reason
) {
344 case VIRTIO_SCSI_EVT_RESET_RESCAN
:
345 scsi_add_device(shost
, 0, target
, lun
);
347 case VIRTIO_SCSI_EVT_RESET_REMOVED
:
348 sdev
= scsi_device_lookup(shost
, 0, target
, lun
);
350 scsi_remove_device(sdev
);
351 scsi_device_put(sdev
);
353 pr_err("SCSI device %d 0 %d %d not found\n",
354 shost
->host_no
, target
, lun
);
358 pr_info("Unsupport virtio scsi event reason %x\n", event
->reason
);
362 static void virtscsi_handle_param_change(struct virtio_scsi
*vscsi
,
363 struct virtio_scsi_event
*event
)
365 struct scsi_device
*sdev
;
366 struct Scsi_Host
*shost
= virtio_scsi_host(vscsi
->vdev
);
367 unsigned int target
= event
->lun
[1];
368 unsigned int lun
= (event
->lun
[2] << 8) | event
->lun
[3];
369 u8 asc
= event
->reason
& 255;
370 u8 ascq
= event
->reason
>> 8;
372 sdev
= scsi_device_lookup(shost
, 0, target
, lun
);
374 pr_err("SCSI device %d 0 %d %d not found\n",
375 shost
->host_no
, target
, lun
);
379 /* Handle "Parameters changed", "Mode parameters changed", and
380 "Capacity data has changed". */
381 if (asc
== 0x2a && (ascq
== 0x00 || ascq
== 0x01 || ascq
== 0x09))
382 scsi_rescan_device(&sdev
->sdev_gendev
);
384 scsi_device_put(sdev
);
387 static void virtscsi_handle_event(struct work_struct
*work
)
389 struct virtio_scsi_event_node
*event_node
=
390 container_of(work
, struct virtio_scsi_event_node
, work
);
391 struct virtio_scsi
*vscsi
= event_node
->vscsi
;
392 struct virtio_scsi_event
*event
= &event_node
->event
;
394 if (event
->event
& VIRTIO_SCSI_T_EVENTS_MISSED
) {
395 event
->event
&= ~VIRTIO_SCSI_T_EVENTS_MISSED
;
396 scsi_scan_host(virtio_scsi_host(vscsi
->vdev
));
399 switch (event
->event
) {
400 case VIRTIO_SCSI_T_NO_EVENT
:
402 case VIRTIO_SCSI_T_TRANSPORT_RESET
:
403 virtscsi_handle_transport_reset(vscsi
, event
);
405 case VIRTIO_SCSI_T_PARAM_CHANGE
:
406 virtscsi_handle_param_change(vscsi
, event
);
409 pr_err("Unsupport virtio scsi event %x\n", event
->event
);
411 virtscsi_kick_event(vscsi
, event_node
);
414 static void virtscsi_complete_event(struct virtio_scsi
*vscsi
, void *buf
)
416 struct virtio_scsi_event_node
*event_node
= buf
;
418 INIT_WORK(&event_node
->work
, virtscsi_handle_event
);
419 schedule_work(&event_node
->work
);
422 static void virtscsi_event_done(struct virtqueue
*vq
)
424 struct Scsi_Host
*sh
= virtio_scsi_host(vq
->vdev
);
425 struct virtio_scsi
*vscsi
= shost_priv(sh
);
427 virtscsi_vq_done(vscsi
, &vscsi
->event_vq
, virtscsi_complete_event
);
431 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
432 * @vq : the struct virtqueue we're talking about
433 * @cmd : command structure
434 * @req_size : size of the request buffer
435 * @resp_size : size of the response buffer
436 * @gfp : flags to use for memory allocations
438 static int virtscsi_add_cmd(struct virtqueue
*vq
,
439 struct virtio_scsi_cmd
*cmd
,
440 size_t req_size
, size_t resp_size
, gfp_t gfp
)
442 struct scsi_cmnd
*sc
= cmd
->sc
;
443 struct scatterlist
*sgs
[4], req
, resp
;
444 struct sg_table
*out
, *in
;
445 unsigned out_num
= 0, in_num
= 0;
449 if (sc
&& sc
->sc_data_direction
!= DMA_NONE
) {
450 if (sc
->sc_data_direction
!= DMA_FROM_DEVICE
)
451 out
= &scsi_out(sc
)->table
;
452 if (sc
->sc_data_direction
!= DMA_TO_DEVICE
)
453 in
= &scsi_in(sc
)->table
;
456 /* Request header. */
457 sg_init_one(&req
, &cmd
->req
, req_size
);
458 sgs
[out_num
++] = &req
;
460 /* Data-out buffer. */
462 sgs
[out_num
++] = out
->sgl
;
464 /* Response header. */
465 sg_init_one(&resp
, &cmd
->resp
, resp_size
);
466 sgs
[out_num
+ in_num
++] = &resp
;
470 sgs
[out_num
+ in_num
++] = in
->sgl
;
472 return virtqueue_add_sgs(vq
, sgs
, out_num
, in_num
, cmd
, gfp
);
475 static int virtscsi_kick_cmd(struct virtio_scsi_vq
*vq
,
476 struct virtio_scsi_cmd
*cmd
,
477 size_t req_size
, size_t resp_size
, gfp_t gfp
)
481 bool needs_kick
= false;
483 spin_lock_irqsave(&vq
->vq_lock
, flags
);
484 err
= virtscsi_add_cmd(vq
->vq
, cmd
, req_size
, resp_size
, gfp
);
486 needs_kick
= virtqueue_kick_prepare(vq
->vq
);
488 spin_unlock_irqrestore(&vq
->vq_lock
, flags
);
491 virtqueue_notify(vq
->vq
);
495 static int virtscsi_queuecommand(struct virtio_scsi
*vscsi
,
496 struct virtio_scsi_vq
*req_vq
,
497 struct scsi_cmnd
*sc
)
499 struct virtio_scsi_cmd
*cmd
;
502 struct Scsi_Host
*shost
= virtio_scsi_host(vscsi
->vdev
);
503 BUG_ON(scsi_sg_count(sc
) > shost
->sg_tablesize
);
505 /* TODO: check feature bit and fail if unsupported? */
506 BUG_ON(sc
->sc_data_direction
== DMA_BIDIRECTIONAL
);
508 dev_dbg(&sc
->device
->sdev_gendev
,
509 "cmd %p CDB: %#02x\n", sc
, sc
->cmnd
[0]);
511 ret
= SCSI_MLQUEUE_HOST_BUSY
;
512 cmd
= mempool_alloc(virtscsi_cmd_pool
, GFP_ATOMIC
);
516 memset(cmd
, 0, sizeof(*cmd
));
518 cmd
->req
.cmd
= (struct virtio_scsi_cmd_req
){
520 .lun
[1] = sc
->device
->id
,
521 .lun
[2] = (sc
->device
->lun
>> 8) | 0x40,
522 .lun
[3] = sc
->device
->lun
& 0xff,
523 .tag
= (unsigned long)sc
,
524 .task_attr
= VIRTIO_SCSI_S_SIMPLE
,
529 BUG_ON(sc
->cmd_len
> VIRTIO_SCSI_CDB_SIZE
);
530 memcpy(cmd
->req
.cmd
.cdb
, sc
->cmnd
, sc
->cmd_len
);
532 if (virtscsi_kick_cmd(req_vq
, cmd
,
533 sizeof cmd
->req
.cmd
, sizeof cmd
->resp
.cmd
,
537 mempool_free(cmd
, virtscsi_cmd_pool
);
543 static int virtscsi_queuecommand_single(struct Scsi_Host
*sh
,
544 struct scsi_cmnd
*sc
)
546 struct virtio_scsi
*vscsi
= shost_priv(sh
);
547 struct virtio_scsi_target_state
*tgt
=
548 scsi_target(sc
->device
)->hostdata
;
550 atomic_inc(&tgt
->reqs
);
551 return virtscsi_queuecommand(vscsi
, &vscsi
->req_vqs
[0], sc
);
554 static struct virtio_scsi_vq
*virtscsi_pick_vq(struct virtio_scsi
*vscsi
,
555 struct virtio_scsi_target_state
*tgt
)
557 struct virtio_scsi_vq
*vq
;
561 spin_lock_irqsave(&tgt
->tgt_lock
, flags
);
564 * The memory barrier after atomic_inc_return matches
565 * the smp_read_barrier_depends() in virtscsi_req_done.
567 if (atomic_inc_return(&tgt
->reqs
) > 1)
568 vq
= ACCESS_ONCE(tgt
->req_vq
);
570 queue_num
= smp_processor_id();
571 while (unlikely(queue_num
>= vscsi
->num_queues
))
572 queue_num
-= vscsi
->num_queues
;
574 tgt
->req_vq
= vq
= &vscsi
->req_vqs
[queue_num
];
577 spin_unlock_irqrestore(&tgt
->tgt_lock
, flags
);
581 static int virtscsi_queuecommand_multi(struct Scsi_Host
*sh
,
582 struct scsi_cmnd
*sc
)
584 struct virtio_scsi
*vscsi
= shost_priv(sh
);
585 struct virtio_scsi_target_state
*tgt
=
586 scsi_target(sc
->device
)->hostdata
;
587 struct virtio_scsi_vq
*req_vq
= virtscsi_pick_vq(vscsi
, tgt
);
589 return virtscsi_queuecommand(vscsi
, req_vq
, sc
);
592 static int virtscsi_tmf(struct virtio_scsi
*vscsi
, struct virtio_scsi_cmd
*cmd
)
594 DECLARE_COMPLETION_ONSTACK(comp
);
598 if (virtscsi_kick_cmd(&vscsi
->ctrl_vq
, cmd
,
599 sizeof cmd
->req
.tmf
, sizeof cmd
->resp
.tmf
,
603 wait_for_completion(&comp
);
604 if (cmd
->resp
.tmf
.response
== VIRTIO_SCSI_S_OK
||
605 cmd
->resp
.tmf
.response
== VIRTIO_SCSI_S_FUNCTION_SUCCEEDED
)
609 mempool_free(cmd
, virtscsi_cmd_pool
);
613 static int virtscsi_device_reset(struct scsi_cmnd
*sc
)
615 struct virtio_scsi
*vscsi
= shost_priv(sc
->device
->host
);
616 struct virtio_scsi_cmd
*cmd
;
618 sdev_printk(KERN_INFO
, sc
->device
, "device reset\n");
619 cmd
= mempool_alloc(virtscsi_cmd_pool
, GFP_NOIO
);
623 memset(cmd
, 0, sizeof(*cmd
));
625 cmd
->req
.tmf
= (struct virtio_scsi_ctrl_tmf_req
){
626 .type
= VIRTIO_SCSI_T_TMF
,
627 .subtype
= VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET
,
629 .lun
[1] = sc
->device
->id
,
630 .lun
[2] = (sc
->device
->lun
>> 8) | 0x40,
631 .lun
[3] = sc
->device
->lun
& 0xff,
633 return virtscsi_tmf(vscsi
, cmd
);
636 static int virtscsi_abort(struct scsi_cmnd
*sc
)
638 struct virtio_scsi
*vscsi
= shost_priv(sc
->device
->host
);
639 struct virtio_scsi_cmd
*cmd
;
641 scmd_printk(KERN_INFO
, sc
, "abort\n");
642 cmd
= mempool_alloc(virtscsi_cmd_pool
, GFP_NOIO
);
646 memset(cmd
, 0, sizeof(*cmd
));
648 cmd
->req
.tmf
= (struct virtio_scsi_ctrl_tmf_req
){
649 .type
= VIRTIO_SCSI_T_TMF
,
650 .subtype
= VIRTIO_SCSI_T_TMF_ABORT_TASK
,
652 .lun
[1] = sc
->device
->id
,
653 .lun
[2] = (sc
->device
->lun
>> 8) | 0x40,
654 .lun
[3] = sc
->device
->lun
& 0xff,
655 .tag
= (unsigned long)sc
,
657 return virtscsi_tmf(vscsi
, cmd
);
660 static int virtscsi_target_alloc(struct scsi_target
*starget
)
662 struct virtio_scsi_target_state
*tgt
=
663 kmalloc(sizeof(*tgt
), GFP_KERNEL
);
667 spin_lock_init(&tgt
->tgt_lock
);
668 atomic_set(&tgt
->reqs
, 0);
671 starget
->hostdata
= tgt
;
675 static void virtscsi_target_destroy(struct scsi_target
*starget
)
677 struct virtio_scsi_target_state
*tgt
= starget
->hostdata
;
681 static struct scsi_host_template virtscsi_host_template_single
= {
682 .module
= THIS_MODULE
,
683 .name
= "Virtio SCSI HBA",
684 .proc_name
= "virtio_scsi",
686 .queuecommand
= virtscsi_queuecommand_single
,
687 .eh_abort_handler
= virtscsi_abort
,
688 .eh_device_reset_handler
= virtscsi_device_reset
,
691 .dma_boundary
= UINT_MAX
,
692 .use_clustering
= ENABLE_CLUSTERING
,
693 .target_alloc
= virtscsi_target_alloc
,
694 .target_destroy
= virtscsi_target_destroy
,
697 static struct scsi_host_template virtscsi_host_template_multi
= {
698 .module
= THIS_MODULE
,
699 .name
= "Virtio SCSI HBA",
700 .proc_name
= "virtio_scsi",
702 .queuecommand
= virtscsi_queuecommand_multi
,
703 .eh_abort_handler
= virtscsi_abort
,
704 .eh_device_reset_handler
= virtscsi_device_reset
,
707 .dma_boundary
= UINT_MAX
,
708 .use_clustering
= ENABLE_CLUSTERING
,
709 .target_alloc
= virtscsi_target_alloc
,
710 .target_destroy
= virtscsi_target_destroy
,
713 #define virtscsi_config_get(vdev, fld) \
715 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
716 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
720 #define virtscsi_config_set(vdev, fld, val) \
722 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
723 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
726 static void __virtscsi_set_affinity(struct virtio_scsi
*vscsi
, bool affinity
)
731 /* In multiqueue mode, when the number of cpu is equal
732 * to the number of request queues, we let the qeueues
733 * to be private to one cpu by setting the affinity hint
734 * to eliminate the contention.
736 if ((vscsi
->num_queues
== 1 ||
737 vscsi
->num_queues
!= num_online_cpus()) && affinity
) {
738 if (vscsi
->affinity_hint_set
)
746 for_each_online_cpu(cpu
) {
747 virtqueue_set_affinity(vscsi
->req_vqs
[i
].vq
, cpu
);
751 vscsi
->affinity_hint_set
= true;
753 for (i
= 0; i
< vscsi
->num_queues
; i
++)
754 virtqueue_set_affinity(vscsi
->req_vqs
[i
].vq
, -1);
756 vscsi
->affinity_hint_set
= false;
760 static void virtscsi_set_affinity(struct virtio_scsi
*vscsi
, bool affinity
)
763 __virtscsi_set_affinity(vscsi
, affinity
);
767 static int virtscsi_cpu_callback(struct notifier_block
*nfb
,
768 unsigned long action
, void *hcpu
)
770 struct virtio_scsi
*vscsi
= container_of(nfb
, struct virtio_scsi
, nb
);
773 case CPU_ONLINE_FROZEN
:
775 case CPU_DEAD_FROZEN
:
776 __virtscsi_set_affinity(vscsi
, true);
784 static void virtscsi_init_vq(struct virtio_scsi_vq
*virtscsi_vq
,
785 struct virtqueue
*vq
)
787 spin_lock_init(&virtscsi_vq
->vq_lock
);
788 virtscsi_vq
->vq
= vq
;
791 static void virtscsi_scan(struct virtio_device
*vdev
)
793 struct Scsi_Host
*shost
= (struct Scsi_Host
*)vdev
->priv
;
795 scsi_scan_host(shost
);
798 static void virtscsi_remove_vqs(struct virtio_device
*vdev
)
800 struct Scsi_Host
*sh
= virtio_scsi_host(vdev
);
801 struct virtio_scsi
*vscsi
= shost_priv(sh
);
803 virtscsi_set_affinity(vscsi
, false);
805 /* Stop all the virtqueues. */
806 vdev
->config
->reset(vdev
);
808 vdev
->config
->del_vqs(vdev
);
811 static int virtscsi_init(struct virtio_device
*vdev
,
812 struct virtio_scsi
*vscsi
)
817 vq_callback_t
**callbacks
;
819 struct virtqueue
**vqs
;
821 num_vqs
= vscsi
->num_queues
+ VIRTIO_SCSI_VQ_BASE
;
822 vqs
= kmalloc(num_vqs
* sizeof(struct virtqueue
*), GFP_KERNEL
);
823 callbacks
= kmalloc(num_vqs
* sizeof(vq_callback_t
*), GFP_KERNEL
);
824 names
= kmalloc(num_vqs
* sizeof(char *), GFP_KERNEL
);
826 if (!callbacks
|| !vqs
|| !names
) {
831 callbacks
[0] = virtscsi_ctrl_done
;
832 callbacks
[1] = virtscsi_event_done
;
833 names
[0] = "control";
835 for (i
= VIRTIO_SCSI_VQ_BASE
; i
< num_vqs
; i
++) {
836 callbacks
[i
] = virtscsi_req_done
;
837 names
[i
] = "request";
840 /* Discover virtqueues and write information to configuration. */
841 err
= vdev
->config
->find_vqs(vdev
, num_vqs
, vqs
, callbacks
, names
);
845 virtscsi_init_vq(&vscsi
->ctrl_vq
, vqs
[0]);
846 virtscsi_init_vq(&vscsi
->event_vq
, vqs
[1]);
847 for (i
= VIRTIO_SCSI_VQ_BASE
; i
< num_vqs
; i
++)
848 virtscsi_init_vq(&vscsi
->req_vqs
[i
- VIRTIO_SCSI_VQ_BASE
],
851 virtscsi_set_affinity(vscsi
, true);
853 virtscsi_config_set(vdev
, cdb_size
, VIRTIO_SCSI_CDB_SIZE
);
854 virtscsi_config_set(vdev
, sense_size
, VIRTIO_SCSI_SENSE_SIZE
);
856 if (virtio_has_feature(vdev
, VIRTIO_SCSI_F_HOTPLUG
))
857 virtscsi_kick_event_all(vscsi
);
866 virtscsi_remove_vqs(vdev
);
870 static int virtscsi_probe(struct virtio_device
*vdev
)
872 struct Scsi_Host
*shost
;
873 struct virtio_scsi
*vscsi
;
875 u32 sg_elems
, num_targets
;
878 struct scsi_host_template
*hostt
;
880 /* We need to know how many queues before we allocate. */
881 num_queues
= virtscsi_config_get(vdev
, num_queues
) ? : 1;
883 num_targets
= virtscsi_config_get(vdev
, max_target
) + 1;
886 hostt
= &virtscsi_host_template_single
;
888 hostt
= &virtscsi_host_template_multi
;
890 shost
= scsi_host_alloc(hostt
,
891 sizeof(*vscsi
) + sizeof(vscsi
->req_vqs
[0]) * num_queues
);
895 sg_elems
= virtscsi_config_get(vdev
, seg_max
) ?: 1;
896 shost
->sg_tablesize
= sg_elems
;
897 vscsi
= shost_priv(shost
);
899 vscsi
->num_queues
= num_queues
;
902 err
= virtscsi_init(vdev
, vscsi
);
904 goto virtscsi_init_failed
;
906 vscsi
->nb
.notifier_call
= &virtscsi_cpu_callback
;
907 err
= register_hotcpu_notifier(&vscsi
->nb
);
909 pr_err("registering cpu notifier failed\n");
910 goto scsi_add_host_failed
;
913 cmd_per_lun
= virtscsi_config_get(vdev
, cmd_per_lun
) ?: 1;
914 shost
->cmd_per_lun
= min_t(u32
, cmd_per_lun
, shost
->can_queue
);
915 shost
->max_sectors
= virtscsi_config_get(vdev
, max_sectors
) ?: 0xFFFF;
917 /* LUNs > 256 are reported with format 1, so they go in the range
920 shost
->max_lun
= virtscsi_config_get(vdev
, max_lun
) + 1 + 0x4000;
921 shost
->max_id
= num_targets
;
922 shost
->max_channel
= 0;
923 shost
->max_cmd_len
= VIRTIO_SCSI_CDB_SIZE
;
924 err
= scsi_add_host(shost
, &vdev
->dev
);
926 goto scsi_add_host_failed
;
928 * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
929 * after VIRTIO_CONFIG_S_DRIVER_OK has been set..
933 scsi_add_host_failed
:
934 vdev
->config
->del_vqs(vdev
);
935 virtscsi_init_failed
:
936 scsi_host_put(shost
);
940 static void virtscsi_remove(struct virtio_device
*vdev
)
942 struct Scsi_Host
*shost
= virtio_scsi_host(vdev
);
943 struct virtio_scsi
*vscsi
= shost_priv(shost
);
945 if (virtio_has_feature(vdev
, VIRTIO_SCSI_F_HOTPLUG
))
946 virtscsi_cancel_event_work(vscsi
);
948 scsi_remove_host(shost
);
950 unregister_hotcpu_notifier(&vscsi
->nb
);
952 virtscsi_remove_vqs(vdev
);
953 scsi_host_put(shost
);
956 #ifdef CONFIG_PM_SLEEP
957 static int virtscsi_freeze(struct virtio_device
*vdev
)
959 struct Scsi_Host
*sh
= virtio_scsi_host(vdev
);
960 struct virtio_scsi
*vscsi
= shost_priv(sh
);
962 unregister_hotcpu_notifier(&vscsi
->nb
);
963 virtscsi_remove_vqs(vdev
);
967 static int virtscsi_restore(struct virtio_device
*vdev
)
969 struct Scsi_Host
*sh
= virtio_scsi_host(vdev
);
970 struct virtio_scsi
*vscsi
= shost_priv(sh
);
973 err
= virtscsi_init(vdev
, vscsi
);
977 err
= register_hotcpu_notifier(&vscsi
->nb
);
979 vdev
->config
->del_vqs(vdev
);
985 static struct virtio_device_id id_table
[] = {
986 { VIRTIO_ID_SCSI
, VIRTIO_DEV_ANY_ID
},
990 static unsigned int features
[] = {
991 VIRTIO_SCSI_F_HOTPLUG
,
992 VIRTIO_SCSI_F_CHANGE
,
995 static struct virtio_driver virtio_scsi_driver
= {
996 .feature_table
= features
,
997 .feature_table_size
= ARRAY_SIZE(features
),
998 .driver
.name
= KBUILD_MODNAME
,
999 .driver
.owner
= THIS_MODULE
,
1000 .id_table
= id_table
,
1001 .probe
= virtscsi_probe
,
1002 .scan
= virtscsi_scan
,
1003 #ifdef CONFIG_PM_SLEEP
1004 .freeze
= virtscsi_freeze
,
1005 .restore
= virtscsi_restore
,
1007 .remove
= virtscsi_remove
,
1010 static int __init
init(void)
1014 virtscsi_cmd_cache
= KMEM_CACHE(virtio_scsi_cmd
, 0);
1015 if (!virtscsi_cmd_cache
) {
1016 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1022 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ
,
1023 virtscsi_cmd_cache
);
1024 if (!virtscsi_cmd_pool
) {
1025 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1028 ret
= register_virtio_driver(&virtio_scsi_driver
);
1035 if (virtscsi_cmd_pool
) {
1036 mempool_destroy(virtscsi_cmd_pool
);
1037 virtscsi_cmd_pool
= NULL
;
1039 if (virtscsi_cmd_cache
) {
1040 kmem_cache_destroy(virtscsi_cmd_cache
);
1041 virtscsi_cmd_cache
= NULL
;
1046 static void __exit
fini(void)
1048 unregister_virtio_driver(&virtio_scsi_driver
);
1049 mempool_destroy(virtscsi_cmd_pool
);
1050 kmem_cache_destroy(virtscsi_cmd_cache
);
1055 MODULE_DEVICE_TABLE(virtio
, id_table
);
1056 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1057 MODULE_LICENSE("GPL");