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sctp: translate host order to network order when setting a hmacid
[linux/fpc-iii.git] / drivers / scsi / virtio_scsi.c
blob11f5326f449f6871e56afdf82f5741c03a2bc730
1 /*
2 * Virtio SCSI HBA driver
3 *
4 * Copyright IBM Corp. 2010
5 * Copyright Red Hat, Inc. 2011
6 *
7 * Authors:
8 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
9 * Paolo Bonzini <pbonzini@redhat.com>
10 *
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.
13 *
14 */
15
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
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>
29
30 #define VIRTIO_SCSI_MEMPOOL_SZ 64
31 #define VIRTIO_SCSI_EVENT_LEN 8
32 #define VIRTIO_SCSI_VQ_BASE 2
33
34 /* Command queue element */
35 struct virtio_scsi_cmd {
36 struct scsi_cmnd *sc;
37 struct completion *comp;
38 union {
39 struct virtio_scsi_cmd_req cmd;
40 struct virtio_scsi_ctrl_tmf_req tmf;
41 struct virtio_scsi_ctrl_an_req an;
42 } req;
43 union {
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;
48 } resp;
49 } ____cacheline_aligned_in_smp;
50
51 struct virtio_scsi_event_node {
52 struct virtio_scsi *vscsi;
53 struct virtio_scsi_event event;
54 struct work_struct work;
55 };
56
57 struct virtio_scsi_vq {
58 /* Protects vq */
59 spinlock_t vq_lock;
60
61 struct virtqueue *vq;
62 };
63
64 /*
65 * Per-target queue state.
66 *
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).
75 *
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:
78 *
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.
82 *
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.
85 *
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
88 * an atomic_t.
89 */
90 struct virtio_scsi_target_state {
91 /* This spinlock never held at the same time as vq_lock. */
92 spinlock_t tgt_lock;
93
94 /* Count of outstanding requests. */
95 atomic_t reqs;
96
97 /* Currently active virtqueue for requests sent to this target. */
98 struct virtio_scsi_vq *req_vq;
99 };
100
101 /* Driver instance state */
102 struct virtio_scsi {
103 struct virtio_device *vdev;
104
105 /* Get some buffers ready for event vq */
106 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
107
108 u32 num_queues;
109
110 /* If the affinity hint is set for virtqueues */
111 bool affinity_hint_set;
112
113 /* CPU hotplug notifier */
114 struct notifier_block nb;
115
116 struct virtio_scsi_vq ctrl_vq;
117 struct virtio_scsi_vq event_vq;
118 struct virtio_scsi_vq req_vqs[];
119 };
120
121 static struct kmem_cache *virtscsi_cmd_cache;
122 static mempool_t *virtscsi_cmd_pool;
123
124 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
125 {
126 return vdev->priv;
127 }
128
129 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
130 {
131 if (!resid)
132 return;
133
134 if (!scsi_bidi_cmnd(sc)) {
135 scsi_set_resid(sc, resid);
136 return;
137 }
138
139 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
140 scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
141 }
142
143 /**
144 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
145 *
146 * Called with vq_lock held.
147 */
148 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
149 {
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;
155
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);
159
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);
165 break;
166 case VIRTIO_SCSI_S_OVERRUN:
167 set_host_byte(sc, DID_ERROR);
168 break;
169 case VIRTIO_SCSI_S_ABORTED:
170 set_host_byte(sc, DID_ABORT);
171 break;
172 case VIRTIO_SCSI_S_BAD_TARGET:
173 set_host_byte(sc, DID_BAD_TARGET);
174 break;
175 case VIRTIO_SCSI_S_RESET:
176 set_host_byte(sc, DID_RESET);
177 break;
178 case VIRTIO_SCSI_S_BUSY:
179 set_host_byte(sc, DID_BUS_BUSY);
180 break;
181 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
182 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
183 break;
184 case VIRTIO_SCSI_S_TARGET_FAILURE:
185 set_host_byte(sc, DID_TARGET_FAILURE);
186 break;
187 case VIRTIO_SCSI_S_NEXUS_FAILURE:
188 set_host_byte(sc, DID_NEXUS_FAILURE);
189 break;
190 default:
191 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
192 resp->response);
193 /* fall through */
194 case VIRTIO_SCSI_S_FAILURE:
195 set_host_byte(sc, DID_ERROR);
196 break;
197 }
198
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));
203 if (resp->sense_len)
204 set_driver_byte(sc, DRIVER_SENSE);
205 }
206
207 mempool_free(cmd, virtscsi_cmd_pool);
208 sc->scsi_done(sc);
209
210 atomic_dec(&tgt->reqs);
211 }
212
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))
216 {
217 void *buf;
218 unsigned int len;
219 unsigned long flags;
220 struct virtqueue *vq = virtscsi_vq->vq;
221
222 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
223 do {
224 virtqueue_disable_cb(vq);
225 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
226 fn(vscsi, buf);
227 } while (!virtqueue_enable_cb(vq));
228 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
229 }
230
231 static void virtscsi_req_done(struct virtqueue *vq)
232 {
233 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
234 struct virtio_scsi *vscsi = shost_priv(sh);
235 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
236 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
237
238 /*
239 * Read req_vq before decrementing the reqs field in
240 * virtscsi_complete_cmd.
241 *
242 * With barriers:
243 *
244 * CPU #0 virtscsi_queuecommand_multi (CPU #1)
245 * ------------------------------------------------------------
246 * lock vq_lock
247 * read req_vq
248 * read reqs (reqs = 1)
249 * write reqs (reqs = 0)
250 * increment reqs (reqs = 1)
251 * write req_vq
252 *
253 * Possible reordering without barriers:
254 *
255 * CPU #0 virtscsi_queuecommand_multi (CPU #1)
256 * ------------------------------------------------------------
257 * lock vq_lock
258 * read reqs (reqs = 1)
259 * write reqs (reqs = 0)
260 * increment reqs (reqs = 1)
261 * write req_vq
262 * read (wrong) req_vq
263 *
264 * We do not need a full smp_rmb, because req_vq is required to get
265 * to tgt->reqs: tgt is &vscsi->tgt[sc->device->id], where sc is stored
266 * in the virtqueue as the user token.
267 */
268 smp_read_barrier_depends();
269
270 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
271 };
272
273 static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
274 {
275 int i, num_vqs;
276
277 num_vqs = vscsi->num_queues;
278 for (i = 0; i < num_vqs; i++)
279 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
280 virtscsi_complete_cmd);
281 }
282
283 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
284 {
285 struct virtio_scsi_cmd *cmd = buf;
286
287 if (cmd->comp)
288 complete_all(cmd->comp);
289 else
290 mempool_free(cmd, virtscsi_cmd_pool);
291 }
292
293 static void virtscsi_ctrl_done(struct virtqueue *vq)
294 {
295 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
296 struct virtio_scsi *vscsi = shost_priv(sh);
297
298 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
299 };
300
301 static void virtscsi_handle_event(struct work_struct *work);
302
303 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
304 struct virtio_scsi_event_node *event_node)
305 {
306 int err;
307 struct scatterlist sg;
308 unsigned long flags;
309
310 INIT_WORK(&event_node->work, virtscsi_handle_event);
311 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
312
313 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
314
315 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
316 GFP_ATOMIC);
317 if (!err)
318 virtqueue_kick(vscsi->event_vq.vq);
319
320 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
321
322 return err;
323 }
324
325 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
326 {
327 int i;
328
329 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
330 vscsi->event_list[i].vscsi = vscsi;
331 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
332 }
333
334 return 0;
335 }
336
337 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
338 {
339 int i;
340
341 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
342 cancel_work_sync(&vscsi->event_list[i].work);
343 }
344
345 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
346 struct virtio_scsi_event *event)
347 {
348 struct scsi_device *sdev;
349 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
350 unsigned int target = event->lun[1];
351 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
352
353 switch (event->reason) {
354 case VIRTIO_SCSI_EVT_RESET_RESCAN:
355 scsi_add_device(shost, 0, target, lun);
356 break;
357 case VIRTIO_SCSI_EVT_RESET_REMOVED:
358 sdev = scsi_device_lookup(shost, 0, target, lun);
359 if (sdev) {
360 scsi_remove_device(sdev);
361 scsi_device_put(sdev);
362 } else {
363 pr_err("SCSI device %d 0 %d %d not found\n",
364 shost->host_no, target, lun);
365 }
366 break;
367 default:
368 pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
369 }
370 }
371
372 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
373 struct virtio_scsi_event *event)
374 {
375 struct scsi_device *sdev;
376 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
377 unsigned int target = event->lun[1];
378 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
379 u8 asc = event->reason & 255;
380 u8 ascq = event->reason >> 8;
381
382 sdev = scsi_device_lookup(shost, 0, target, lun);
383 if (!sdev) {
384 pr_err("SCSI device %d 0 %d %d not found\n",
385 shost->host_no, target, lun);
386 return;
387 }
388
389 /* Handle "Parameters changed", "Mode parameters changed", and
390 "Capacity data has changed". */
391 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
392 scsi_rescan_device(&sdev->sdev_gendev);
393
394 scsi_device_put(sdev);
395 }
396
397 static void virtscsi_handle_event(struct work_struct *work)
398 {
399 struct virtio_scsi_event_node *event_node =
400 container_of(work, struct virtio_scsi_event_node, work);
401 struct virtio_scsi *vscsi = event_node->vscsi;
402 struct virtio_scsi_event *event = &event_node->event;
403
404 if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
405 event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
406 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
407 }
408
409 switch (event->event) {
410 case VIRTIO_SCSI_T_NO_EVENT:
411 break;
412 case VIRTIO_SCSI_T_TRANSPORT_RESET:
413 virtscsi_handle_transport_reset(vscsi, event);
414 break;
415 case VIRTIO_SCSI_T_PARAM_CHANGE:
416 virtscsi_handle_param_change(vscsi, event);
417 break;
418 default:
419 pr_err("Unsupport virtio scsi event %x\n", event->event);
420 }
421 virtscsi_kick_event(vscsi, event_node);
422 }
423
424 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
425 {
426 struct virtio_scsi_event_node *event_node = buf;
427
428 schedule_work(&event_node->work);
429 }
430
431 static void virtscsi_event_done(struct virtqueue *vq)
432 {
433 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
434 struct virtio_scsi *vscsi = shost_priv(sh);
435
436 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
437 };
438
439 /**
440 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
441 * @vq : the struct virtqueue we're talking about
442 * @cmd : command structure
443 * @req_size : size of the request buffer
444 * @resp_size : size of the response buffer
445 * @gfp : flags to use for memory allocations
446 */
447 static int virtscsi_add_cmd(struct virtqueue *vq,
448 struct virtio_scsi_cmd *cmd,
449 size_t req_size, size_t resp_size, gfp_t gfp)
450 {
451 struct scsi_cmnd *sc = cmd->sc;
452 struct scatterlist *sgs[4], req, resp;
453 struct sg_table *out, *in;
454 unsigned out_num = 0, in_num = 0;
455
456 out = in = NULL;
457
458 if (sc && sc->sc_data_direction != DMA_NONE) {
459 if (sc->sc_data_direction != DMA_FROM_DEVICE)
460 out = &scsi_out(sc)->table;
461 if (sc->sc_data_direction != DMA_TO_DEVICE)
462 in = &scsi_in(sc)->table;
463 }
464
465 /* Request header. */
466 sg_init_one(&req, &cmd->req, req_size);
467 sgs[out_num++] = &req;
468
469 /* Data-out buffer. */
470 if (out)
471 sgs[out_num++] = out->sgl;
472
473 /* Response header. */
474 sg_init_one(&resp, &cmd->resp, resp_size);
475 sgs[out_num + in_num++] = &resp;
476
477 /* Data-in buffer */
478 if (in)
479 sgs[out_num + in_num++] = in->sgl;
480
481 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
482 }
483
484 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
485 struct virtio_scsi_cmd *cmd,
486 size_t req_size, size_t resp_size, gfp_t gfp)
487 {
488 unsigned long flags;
489 int err;
490 bool needs_kick = false;
491
492 spin_lock_irqsave(&vq->vq_lock, flags);
493 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp);
494 if (!err)
495 needs_kick = virtqueue_kick_prepare(vq->vq);
496
497 spin_unlock_irqrestore(&vq->vq_lock, flags);
498
499 if (needs_kick)
500 virtqueue_notify(vq->vq);
501 return err;
502 }
503
504 static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
505 struct virtio_scsi_vq *req_vq,
506 struct scsi_cmnd *sc)
507 {
508 struct virtio_scsi_cmd *cmd;
509 int ret;
510
511 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
512 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
513
514 /* TODO: check feature bit and fail if unsupported? */
515 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
516
517 dev_dbg(&sc->device->sdev_gendev,
518 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
519
520 ret = SCSI_MLQUEUE_HOST_BUSY;
521 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC);
522 if (!cmd)
523 goto out;
524
525 memset(cmd, 0, sizeof(*cmd));
526 cmd->sc = sc;
527 cmd->req.cmd = (struct virtio_scsi_cmd_req){
528 .lun[0] = 1,
529 .lun[1] = sc->device->id,
530 .lun[2] = (sc->device->lun >> 8) | 0x40,
531 .lun[3] = sc->device->lun & 0xff,
532 .tag = (unsigned long)sc,
533 .task_attr = VIRTIO_SCSI_S_SIMPLE,
534 .prio = 0,
535 .crn = 0,
536 };
537
538 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
539 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
540
541 if (virtscsi_kick_cmd(req_vq, cmd,
542 sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
543 GFP_ATOMIC) == 0)
544 ret = 0;
545 else
546 mempool_free(cmd, virtscsi_cmd_pool);
547
548 out:
549 return ret;
550 }
551
552 static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
553 struct scsi_cmnd *sc)
554 {
555 struct virtio_scsi *vscsi = shost_priv(sh);
556 struct virtio_scsi_target_state *tgt =
557 scsi_target(sc->device)->hostdata;
558
559 atomic_inc(&tgt->reqs);
560 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc);
561 }
562
563 static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi,
564 struct virtio_scsi_target_state *tgt)
565 {
566 struct virtio_scsi_vq *vq;
567 unsigned long flags;
568 u32 queue_num;
569
570 spin_lock_irqsave(&tgt->tgt_lock, flags);
571
572 /*
573 * The memory barrier after atomic_inc_return matches
574 * the smp_read_barrier_depends() in virtscsi_req_done.
575 */
576 if (atomic_inc_return(&tgt->reqs) > 1)
577 vq = ACCESS_ONCE(tgt->req_vq);
578 else {
579 queue_num = smp_processor_id();
580 while (unlikely(queue_num >= vscsi->num_queues))
581 queue_num -= vscsi->num_queues;
582
583 tgt->req_vq = vq = &vscsi->req_vqs[queue_num];
584 }
585
586 spin_unlock_irqrestore(&tgt->tgt_lock, flags);
587 return vq;
588 }
589
590 static int virtscsi_queuecommand_multi(struct Scsi_Host *sh,
591 struct scsi_cmnd *sc)
592 {
593 struct virtio_scsi *vscsi = shost_priv(sh);
594 struct virtio_scsi_target_state *tgt =
595 scsi_target(sc->device)->hostdata;
596 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt);
597
598 return virtscsi_queuecommand(vscsi, req_vq, sc);
599 }
600
601 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
602 {
603 DECLARE_COMPLETION_ONSTACK(comp);
604 int ret = FAILED;
605
606 cmd->comp = &comp;
607 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
608 sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
609 GFP_NOIO) < 0)
610 goto out;
611
612 wait_for_completion(&comp);
613 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
614 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
615 ret = SUCCESS;
616
617 /*
618 * The spec guarantees that all requests related to the TMF have
619 * been completed, but the callback might not have run yet if
620 * we're using independent interrupts (e.g. MSI). Poll the
621 * virtqueues once.
622 *
623 * In the abort case, sc->scsi_done will do nothing, because
624 * the block layer must have detected a timeout and as a result
625 * REQ_ATOM_COMPLETE has been set.
626 */
627 virtscsi_poll_requests(vscsi);
628
629 out:
630 mempool_free(cmd, virtscsi_cmd_pool);
631 return ret;
632 }
633
634 static int virtscsi_device_reset(struct scsi_cmnd *sc)
635 {
636 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
637 struct virtio_scsi_cmd *cmd;
638
639 sdev_printk(KERN_INFO, sc->device, "device reset\n");
640 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
641 if (!cmd)
642 return FAILED;
643
644 memset(cmd, 0, sizeof(*cmd));
645 cmd->sc = sc;
646 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
647 .type = VIRTIO_SCSI_T_TMF,
648 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
649 .lun[0] = 1,
650 .lun[1] = sc->device->id,
651 .lun[2] = (sc->device->lun >> 8) | 0x40,
652 .lun[3] = sc->device->lun & 0xff,
653 };
654 return virtscsi_tmf(vscsi, cmd);
655 }
656
657 static int virtscsi_abort(struct scsi_cmnd *sc)
658 {
659 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
660 struct virtio_scsi_cmd *cmd;
661
662 scmd_printk(KERN_INFO, sc, "abort\n");
663 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
664 if (!cmd)
665 return FAILED;
666
667 memset(cmd, 0, sizeof(*cmd));
668 cmd->sc = sc;
669 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
670 .type = VIRTIO_SCSI_T_TMF,
671 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
672 .lun[0] = 1,
673 .lun[1] = sc->device->id,
674 .lun[2] = (sc->device->lun >> 8) | 0x40,
675 .lun[3] = sc->device->lun & 0xff,
676 .tag = (unsigned long)sc,
677 };
678 return virtscsi_tmf(vscsi, cmd);
679 }
680
681 static int virtscsi_target_alloc(struct scsi_target *starget)
682 {
683 struct virtio_scsi_target_state *tgt =
684 kmalloc(sizeof(*tgt), GFP_KERNEL);
685 if (!tgt)
686 return -ENOMEM;
687
688 spin_lock_init(&tgt->tgt_lock);
689 atomic_set(&tgt->reqs, 0);
690 tgt->req_vq = NULL;
691
692 starget->hostdata = tgt;
693 return 0;
694 }
695
696 static void virtscsi_target_destroy(struct scsi_target *starget)
697 {
698 struct virtio_scsi_target_state *tgt = starget->hostdata;
699 kfree(tgt);
700 }
701
702 static struct scsi_host_template virtscsi_host_template_single = {
703 .module = THIS_MODULE,
704 .name = "Virtio SCSI HBA",
705 .proc_name = "virtio_scsi",
706 .this_id = -1,
707 .queuecommand = virtscsi_queuecommand_single,
708 .eh_abort_handler = virtscsi_abort,
709 .eh_device_reset_handler = virtscsi_device_reset,
710
711 .can_queue = 1024,
712 .dma_boundary = UINT_MAX,
713 .use_clustering = ENABLE_CLUSTERING,
714 .target_alloc = virtscsi_target_alloc,
715 .target_destroy = virtscsi_target_destroy,
716 };
717
718 static struct scsi_host_template virtscsi_host_template_multi = {
719 .module = THIS_MODULE,
720 .name = "Virtio SCSI HBA",
721 .proc_name = "virtio_scsi",
722 .this_id = -1,
723 .queuecommand = virtscsi_queuecommand_multi,
724 .eh_abort_handler = virtscsi_abort,
725 .eh_device_reset_handler = virtscsi_device_reset,
726
727 .can_queue = 1024,
728 .dma_boundary = UINT_MAX,
729 .use_clustering = ENABLE_CLUSTERING,
730 .target_alloc = virtscsi_target_alloc,
731 .target_destroy = virtscsi_target_destroy,
732 };
733
734 #define virtscsi_config_get(vdev, fld) \
735 ({ \
736 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
737 vdev->config->get(vdev, \
738 offsetof(struct virtio_scsi_config, fld), \
739 &__val, sizeof(__val)); \
740 __val; \
741 })
742
743 #define virtscsi_config_set(vdev, fld, val) \
744 (void)({ \
745 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
746 vdev->config->set(vdev, \
747 offsetof(struct virtio_scsi_config, fld), \
748 &__val, sizeof(__val)); \
749 })
750
751 static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
752 {
753 int i;
754 int cpu;
755
756 /* In multiqueue mode, when the number of cpu is equal
757 * to the number of request queues, we let the qeueues
758 * to be private to one cpu by setting the affinity hint
759 * to eliminate the contention.
760 */
761 if ((vscsi->num_queues == 1 ||
762 vscsi->num_queues != num_online_cpus()) && affinity) {
763 if (vscsi->affinity_hint_set)
764 affinity = false;
765 else
766 return;
767 }
768
769 if (affinity) {
770 i = 0;
771 for_each_online_cpu(cpu) {
772 virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu);
773 i++;
774 }
775
776 vscsi->affinity_hint_set = true;
777 } else {
778 for (i = 0; i < vscsi->num_queues; i++) {
779 if (!vscsi->req_vqs[i].vq)
780 continue;
781
782 virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1);
783 }
784
785 vscsi->affinity_hint_set = false;
786 }
787 }
788
789 static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
790 {
791 get_online_cpus();
792 __virtscsi_set_affinity(vscsi, affinity);
793 put_online_cpus();
794 }
795
796 static int virtscsi_cpu_callback(struct notifier_block *nfb,
797 unsigned long action, void *hcpu)
798 {
799 struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb);
800 switch(action) {
801 case CPU_ONLINE:
802 case CPU_ONLINE_FROZEN:
803 case CPU_DEAD:
804 case CPU_DEAD_FROZEN:
805 __virtscsi_set_affinity(vscsi, true);
806 break;
807 default:
808 break;
809 }
810 return NOTIFY_OK;
811 }
812
813 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
814 struct virtqueue *vq)
815 {
816 spin_lock_init(&virtscsi_vq->vq_lock);
817 virtscsi_vq->vq = vq;
818 }
819
820 static void virtscsi_scan(struct virtio_device *vdev)
821 {
822 struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv;
823
824 scsi_scan_host(shost);
825 }
826
827 static void virtscsi_remove_vqs(struct virtio_device *vdev)
828 {
829 struct Scsi_Host *sh = virtio_scsi_host(vdev);
830 struct virtio_scsi *vscsi = shost_priv(sh);
831
832 virtscsi_set_affinity(vscsi, false);
833
834 /* Stop all the virtqueues. */
835 vdev->config->reset(vdev);
836
837 vdev->config->del_vqs(vdev);
838 }
839
840 static int virtscsi_init(struct virtio_device *vdev,
841 struct virtio_scsi *vscsi)
842 {
843 int err;
844 u32 i;
845 u32 num_vqs;
846 vq_callback_t **callbacks;
847 const char **names;
848 struct virtqueue **vqs;
849
850 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
851 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL);
852 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL);
853 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL);
854
855 if (!callbacks || !vqs || !names) {
856 err = -ENOMEM;
857 goto out;
858 }
859
860 callbacks[0] = virtscsi_ctrl_done;
861 callbacks[1] = virtscsi_event_done;
862 names[0] = "control";
863 names[1] = "event";
864 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
865 callbacks[i] = virtscsi_req_done;
866 names[i] = "request";
867 }
868
869 /* Discover virtqueues and write information to configuration. */
870 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
871 if (err)
872 goto out;
873
874 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
875 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
876 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
877 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
878 vqs[i]);
879
880 virtscsi_set_affinity(vscsi, true);
881
882 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
883 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
884
885 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
886 virtscsi_kick_event_all(vscsi);
887
888 err = 0;
889
890 out:
891 kfree(names);
892 kfree(callbacks);
893 kfree(vqs);
894 if (err)
895 virtscsi_remove_vqs(vdev);
896 return err;
897 }
898
899 static int virtscsi_probe(struct virtio_device *vdev)
900 {
901 struct Scsi_Host *shost;
902 struct virtio_scsi *vscsi;
903 int err;
904 u32 sg_elems, num_targets;
905 u32 cmd_per_lun;
906 u32 num_queues;
907 struct scsi_host_template *hostt;
908
909 /* We need to know how many queues before we allocate. */
910 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
911
912 num_targets = virtscsi_config_get(vdev, max_target) + 1;
913
914 if (num_queues == 1)
915 hostt = &virtscsi_host_template_single;
916 else
917 hostt = &virtscsi_host_template_multi;
918
919 shost = scsi_host_alloc(hostt,
920 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
921 if (!shost)
922 return -ENOMEM;
923
924 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
925 shost->sg_tablesize = sg_elems;
926 vscsi = shost_priv(shost);
927 vscsi->vdev = vdev;
928 vscsi->num_queues = num_queues;
929 vdev->priv = shost;
930
931 err = virtscsi_init(vdev, vscsi);
932 if (err)
933 goto virtscsi_init_failed;
934
935 vscsi->nb.notifier_call = &virtscsi_cpu_callback;
936 err = register_hotcpu_notifier(&vscsi->nb);
937 if (err) {
938 pr_err("registering cpu notifier failed\n");
939 goto scsi_add_host_failed;
940 }
941
942 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
943 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
944 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
945
946 /* LUNs > 256 are reported with format 1, so they go in the range
947 * 16640-32767.
948 */
949 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
950 shost->max_id = num_targets;
951 shost->max_channel = 0;
952 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
953 err = scsi_add_host(shost, &vdev->dev);
954 if (err)
955 goto scsi_add_host_failed;
956 /*
957 * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
958 * after VIRTIO_CONFIG_S_DRIVER_OK has been set..
959 */
960 return 0;
961
962 scsi_add_host_failed:
963 vdev->config->del_vqs(vdev);
964 virtscsi_init_failed:
965 scsi_host_put(shost);
966 return err;
967 }
968
969 static void virtscsi_remove(struct virtio_device *vdev)
970 {
971 struct Scsi_Host *shost = virtio_scsi_host(vdev);
972 struct virtio_scsi *vscsi = shost_priv(shost);
973
974 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
975 virtscsi_cancel_event_work(vscsi);
976
977 scsi_remove_host(shost);
978
979 unregister_hotcpu_notifier(&vscsi->nb);
980
981 virtscsi_remove_vqs(vdev);
982 scsi_host_put(shost);
983 }
984
985 #ifdef CONFIG_PM
986 static int virtscsi_freeze(struct virtio_device *vdev)
987 {
988 struct Scsi_Host *sh = virtio_scsi_host(vdev);
989 struct virtio_scsi *vscsi = shost_priv(sh);
990
991 unregister_hotcpu_notifier(&vscsi->nb);
992 virtscsi_remove_vqs(vdev);
993 return 0;
994 }
995
996 static int virtscsi_restore(struct virtio_device *vdev)
997 {
998 struct Scsi_Host *sh = virtio_scsi_host(vdev);
999 struct virtio_scsi *vscsi = shost_priv(sh);
1000 int err;
1001
1002 err = virtscsi_init(vdev, vscsi);
1003 if (err)
1004 return err;
1005
1006 err = register_hotcpu_notifier(&vscsi->nb);
1007 if (err)
1008 vdev->config->del_vqs(vdev);
1009
1010 return err;
1011 }
1012 #endif
1013
1014 static struct virtio_device_id id_table[] = {
1015 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
1016 { 0 },
1017 };
1018
1019 static unsigned int features[] = {
1020 VIRTIO_SCSI_F_HOTPLUG,
1021 VIRTIO_SCSI_F_CHANGE,
1022 };
1023
1024 static struct virtio_driver virtio_scsi_driver = {
1025 .feature_table = features,
1026 .feature_table_size = ARRAY_SIZE(features),
1027 .driver.name = KBUILD_MODNAME,
1028 .driver.owner = THIS_MODULE,
1029 .id_table = id_table,
1030 .probe = virtscsi_probe,
1031 .scan = virtscsi_scan,
1032 #ifdef CONFIG_PM
1033 .freeze = virtscsi_freeze,
1034 .restore = virtscsi_restore,
1035 #endif
1036 .remove = virtscsi_remove,
1037 };
1038
1039 static int __init init(void)
1040 {
1041 int ret = -ENOMEM;
1042
1043 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1044 if (!virtscsi_cmd_cache) {
1045 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1046 goto error;
1047 }
1048
1049
1050 virtscsi_cmd_pool =
1051 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1052 virtscsi_cmd_cache);
1053 if (!virtscsi_cmd_pool) {
1054 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1055 goto error;
1056 }
1057 ret = register_virtio_driver(&virtio_scsi_driver);
1058 if (ret < 0)
1059 goto error;
1060
1061 return 0;
1062
1063 error:
1064 if (virtscsi_cmd_pool) {
1065 mempool_destroy(virtscsi_cmd_pool);
1066 virtscsi_cmd_pool = NULL;
1067 }
1068 if (virtscsi_cmd_cache) {
1069 kmem_cache_destroy(virtscsi_cmd_cache);
1070 virtscsi_cmd_cache = NULL;
1071 }
1072 return ret;
1073 }
1074
1075 static void __exit fini(void)
1076 {
1077 unregister_virtio_driver(&virtio_scsi_driver);
1078 mempool_destroy(virtscsi_cmd_pool);
1079 kmem_cache_destroy(virtscsi_cmd_cache);
1080 }
1081 module_init(init);
1082 module_exit(fini);
1083
1084 MODULE_DEVICE_TABLE(virtio, id_table);
1085 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1086 MODULE_LICENSE("GPL");
Linux with added FPC-III support