Merge tag 'for-v3.8-merged' of git://git.infradead.org/battery-2.6
[deliverable/linux.git] / drivers / scsi / virtio_scsi.c
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 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/mempool.h>
19 #include <linux/virtio.h>
20 #include <linux/virtio_ids.h>
21 #include <linux/virtio_config.h>
22 #include <linux/virtio_scsi.h>
23 #include <scsi/scsi_host.h>
24 #include <scsi/scsi_device.h>
25 #include <scsi/scsi_cmnd.h>
26
27 #define VIRTIO_SCSI_MEMPOOL_SZ 64
28 #define VIRTIO_SCSI_EVENT_LEN 8
29
30 /* Command queue element */
31 struct virtio_scsi_cmd {
32 struct scsi_cmnd *sc;
33 struct completion *comp;
34 union {
35 struct virtio_scsi_cmd_req cmd;
36 struct virtio_scsi_ctrl_tmf_req tmf;
37 struct virtio_scsi_ctrl_an_req an;
38 } req;
39 union {
40 struct virtio_scsi_cmd_resp cmd;
41 struct virtio_scsi_ctrl_tmf_resp tmf;
42 struct virtio_scsi_ctrl_an_resp an;
43 struct virtio_scsi_event evt;
44 } resp;
45 } ____cacheline_aligned_in_smp;
46
47 struct virtio_scsi_event_node {
48 struct virtio_scsi *vscsi;
49 struct virtio_scsi_event event;
50 struct work_struct work;
51 };
52
53 struct virtio_scsi_vq {
54 /* Protects vq */
55 spinlock_t vq_lock;
56
57 struct virtqueue *vq;
58 };
59
60 /* Per-target queue state */
61 struct virtio_scsi_target_state {
62 /* Protects sg. Lock hierarchy is tgt_lock -> vq_lock. */
63 spinlock_t tgt_lock;
64
65 /* For sglist construction when adding commands to the virtqueue. */
66 struct scatterlist sg[];
67 };
68
69 /* Driver instance state */
70 struct virtio_scsi {
71 struct virtio_device *vdev;
72
73 struct virtio_scsi_vq ctrl_vq;
74 struct virtio_scsi_vq event_vq;
75 struct virtio_scsi_vq req_vq;
76
77 /* Get some buffers ready for event vq */
78 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
79
80 struct virtio_scsi_target_state *tgt[];
81 };
82
83 static struct kmem_cache *virtscsi_cmd_cache;
84 static mempool_t *virtscsi_cmd_pool;
85
86 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
87 {
88 return vdev->priv;
89 }
90
91 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
92 {
93 if (!resid)
94 return;
95
96 if (!scsi_bidi_cmnd(sc)) {
97 scsi_set_resid(sc, resid);
98 return;
99 }
100
101 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
102 scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
103 }
104
105 /**
106 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
107 *
108 * Called with vq_lock held.
109 */
110 static void virtscsi_complete_cmd(void *buf)
111 {
112 struct virtio_scsi_cmd *cmd = buf;
113 struct scsi_cmnd *sc = cmd->sc;
114 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
115
116 dev_dbg(&sc->device->sdev_gendev,
117 "cmd %p response %u status %#02x sense_len %u\n",
118 sc, resp->response, resp->status, resp->sense_len);
119
120 sc->result = resp->status;
121 virtscsi_compute_resid(sc, resp->resid);
122 switch (resp->response) {
123 case VIRTIO_SCSI_S_OK:
124 set_host_byte(sc, DID_OK);
125 break;
126 case VIRTIO_SCSI_S_OVERRUN:
127 set_host_byte(sc, DID_ERROR);
128 break;
129 case VIRTIO_SCSI_S_ABORTED:
130 set_host_byte(sc, DID_ABORT);
131 break;
132 case VIRTIO_SCSI_S_BAD_TARGET:
133 set_host_byte(sc, DID_BAD_TARGET);
134 break;
135 case VIRTIO_SCSI_S_RESET:
136 set_host_byte(sc, DID_RESET);
137 break;
138 case VIRTIO_SCSI_S_BUSY:
139 set_host_byte(sc, DID_BUS_BUSY);
140 break;
141 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
142 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
143 break;
144 case VIRTIO_SCSI_S_TARGET_FAILURE:
145 set_host_byte(sc, DID_TARGET_FAILURE);
146 break;
147 case VIRTIO_SCSI_S_NEXUS_FAILURE:
148 set_host_byte(sc, DID_NEXUS_FAILURE);
149 break;
150 default:
151 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
152 resp->response);
153 /* fall through */
154 case VIRTIO_SCSI_S_FAILURE:
155 set_host_byte(sc, DID_ERROR);
156 break;
157 }
158
159 WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE);
160 if (sc->sense_buffer) {
161 memcpy(sc->sense_buffer, resp->sense,
162 min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
163 if (resp->sense_len)
164 set_driver_byte(sc, DRIVER_SENSE);
165 }
166
167 mempool_free(cmd, virtscsi_cmd_pool);
168 sc->scsi_done(sc);
169 }
170
171 static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
172 {
173 void *buf;
174 unsigned int len;
175
176 do {
177 virtqueue_disable_cb(vq);
178 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
179 fn(buf);
180 } while (!virtqueue_enable_cb(vq));
181 }
182
183 static void virtscsi_req_done(struct virtqueue *vq)
184 {
185 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
186 struct virtio_scsi *vscsi = shost_priv(sh);
187 unsigned long flags;
188
189 spin_lock_irqsave(&vscsi->req_vq.vq_lock, flags);
190 virtscsi_vq_done(vq, virtscsi_complete_cmd);
191 spin_unlock_irqrestore(&vscsi->req_vq.vq_lock, flags);
192 };
193
194 static void virtscsi_complete_free(void *buf)
195 {
196 struct virtio_scsi_cmd *cmd = buf;
197
198 if (cmd->comp)
199 complete_all(cmd->comp);
200 else
201 mempool_free(cmd, virtscsi_cmd_pool);
202 }
203
204 static void virtscsi_ctrl_done(struct virtqueue *vq)
205 {
206 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
207 struct virtio_scsi *vscsi = shost_priv(sh);
208 unsigned long flags;
209
210 spin_lock_irqsave(&vscsi->ctrl_vq.vq_lock, flags);
211 virtscsi_vq_done(vq, virtscsi_complete_free);
212 spin_unlock_irqrestore(&vscsi->ctrl_vq.vq_lock, flags);
213 };
214
215 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
216 struct virtio_scsi_event_node *event_node)
217 {
218 int ret;
219 struct scatterlist sg;
220 unsigned long flags;
221
222 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
223
224 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
225
226 ret = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node, GFP_ATOMIC);
227 if (ret >= 0)
228 virtqueue_kick(vscsi->event_vq.vq);
229
230 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
231
232 return ret;
233 }
234
235 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
236 {
237 int i;
238
239 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
240 vscsi->event_list[i].vscsi = vscsi;
241 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
242 }
243
244 return 0;
245 }
246
247 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
248 {
249 int i;
250
251 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
252 cancel_work_sync(&vscsi->event_list[i].work);
253 }
254
255 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
256 struct virtio_scsi_event *event)
257 {
258 struct scsi_device *sdev;
259 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
260 unsigned int target = event->lun[1];
261 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
262
263 switch (event->reason) {
264 case VIRTIO_SCSI_EVT_RESET_RESCAN:
265 scsi_add_device(shost, 0, target, lun);
266 break;
267 case VIRTIO_SCSI_EVT_RESET_REMOVED:
268 sdev = scsi_device_lookup(shost, 0, target, lun);
269 if (sdev) {
270 scsi_remove_device(sdev);
271 scsi_device_put(sdev);
272 } else {
273 pr_err("SCSI device %d 0 %d %d not found\n",
274 shost->host_no, target, lun);
275 }
276 break;
277 default:
278 pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
279 }
280 }
281
282 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
283 struct virtio_scsi_event *event)
284 {
285 struct scsi_device *sdev;
286 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
287 unsigned int target = event->lun[1];
288 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
289 u8 asc = event->reason & 255;
290 u8 ascq = event->reason >> 8;
291
292 sdev = scsi_device_lookup(shost, 0, target, lun);
293 if (!sdev) {
294 pr_err("SCSI device %d 0 %d %d not found\n",
295 shost->host_no, target, lun);
296 return;
297 }
298
299 /* Handle "Parameters changed", "Mode parameters changed", and
300 "Capacity data has changed". */
301 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
302 scsi_rescan_device(&sdev->sdev_gendev);
303
304 scsi_device_put(sdev);
305 }
306
307 static void virtscsi_handle_event(struct work_struct *work)
308 {
309 struct virtio_scsi_event_node *event_node =
310 container_of(work, struct virtio_scsi_event_node, work);
311 struct virtio_scsi *vscsi = event_node->vscsi;
312 struct virtio_scsi_event *event = &event_node->event;
313
314 if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
315 event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
316 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
317 }
318
319 switch (event->event) {
320 case VIRTIO_SCSI_T_NO_EVENT:
321 break;
322 case VIRTIO_SCSI_T_TRANSPORT_RESET:
323 virtscsi_handle_transport_reset(vscsi, event);
324 break;
325 case VIRTIO_SCSI_T_PARAM_CHANGE:
326 virtscsi_handle_param_change(vscsi, event);
327 break;
328 default:
329 pr_err("Unsupport virtio scsi event %x\n", event->event);
330 }
331 virtscsi_kick_event(vscsi, event_node);
332 }
333
334 static void virtscsi_complete_event(void *buf)
335 {
336 struct virtio_scsi_event_node *event_node = buf;
337
338 INIT_WORK(&event_node->work, virtscsi_handle_event);
339 schedule_work(&event_node->work);
340 }
341
342 static void virtscsi_event_done(struct virtqueue *vq)
343 {
344 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
345 struct virtio_scsi *vscsi = shost_priv(sh);
346 unsigned long flags;
347
348 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
349 virtscsi_vq_done(vq, virtscsi_complete_event);
350 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
351 };
352
353 static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
354 struct scsi_data_buffer *sdb)
355 {
356 struct sg_table *table = &sdb->table;
357 struct scatterlist *sg_elem;
358 unsigned int idx = *p_idx;
359 int i;
360
361 for_each_sg(table->sgl, sg_elem, table->nents, i)
362 sg[idx++] = *sg_elem;
363
364 *p_idx = idx;
365 }
366
367 /**
368 * virtscsi_map_cmd - map a scsi_cmd to a virtqueue scatterlist
369 * @vscsi : virtio_scsi state
370 * @cmd : command structure
371 * @out_num : number of read-only elements
372 * @in_num : number of write-only elements
373 * @req_size : size of the request buffer
374 * @resp_size : size of the response buffer
375 *
376 * Called with tgt_lock held.
377 */
378 static void virtscsi_map_cmd(struct virtio_scsi_target_state *tgt,
379 struct virtio_scsi_cmd *cmd,
380 unsigned *out_num, unsigned *in_num,
381 size_t req_size, size_t resp_size)
382 {
383 struct scsi_cmnd *sc = cmd->sc;
384 struct scatterlist *sg = tgt->sg;
385 unsigned int idx = 0;
386
387 /* Request header. */
388 sg_set_buf(&sg[idx++], &cmd->req, req_size);
389
390 /* Data-out buffer. */
391 if (sc && sc->sc_data_direction != DMA_FROM_DEVICE)
392 virtscsi_map_sgl(sg, &idx, scsi_out(sc));
393
394 *out_num = idx;
395
396 /* Response header. */
397 sg_set_buf(&sg[idx++], &cmd->resp, resp_size);
398
399 /* Data-in buffer */
400 if (sc && sc->sc_data_direction != DMA_TO_DEVICE)
401 virtscsi_map_sgl(sg, &idx, scsi_in(sc));
402
403 *in_num = idx - *out_num;
404 }
405
406 static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
407 struct virtio_scsi_vq *vq,
408 struct virtio_scsi_cmd *cmd,
409 size_t req_size, size_t resp_size, gfp_t gfp)
410 {
411 unsigned int out_num, in_num;
412 unsigned long flags;
413 int ret;
414
415 spin_lock_irqsave(&tgt->tgt_lock, flags);
416 virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
417
418 spin_lock(&vq->vq_lock);
419 ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
420 spin_unlock(&tgt->tgt_lock);
421 if (ret >= 0)
422 ret = virtqueue_kick_prepare(vq->vq);
423
424 spin_unlock_irqrestore(&vq->vq_lock, flags);
425
426 if (ret > 0)
427 virtqueue_notify(vq->vq);
428 return ret;
429 }
430
431 static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
432 {
433 struct virtio_scsi *vscsi = shost_priv(sh);
434 struct virtio_scsi_target_state *tgt = vscsi->tgt[sc->device->id];
435 struct virtio_scsi_cmd *cmd;
436 int ret;
437
438 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
439 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
440
441 /* TODO: check feature bit and fail if unsupported? */
442 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
443
444 dev_dbg(&sc->device->sdev_gendev,
445 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
446
447 ret = SCSI_MLQUEUE_HOST_BUSY;
448 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC);
449 if (!cmd)
450 goto out;
451
452 memset(cmd, 0, sizeof(*cmd));
453 cmd->sc = sc;
454 cmd->req.cmd = (struct virtio_scsi_cmd_req){
455 .lun[0] = 1,
456 .lun[1] = sc->device->id,
457 .lun[2] = (sc->device->lun >> 8) | 0x40,
458 .lun[3] = sc->device->lun & 0xff,
459 .tag = (unsigned long)sc,
460 .task_attr = VIRTIO_SCSI_S_SIMPLE,
461 .prio = 0,
462 .crn = 0,
463 };
464
465 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
466 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
467
468 if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
469 sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
470 GFP_ATOMIC) >= 0)
471 ret = 0;
472 else
473 mempool_free(cmd, virtscsi_cmd_pool);
474
475 out:
476 return ret;
477 }
478
479 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
480 {
481 DECLARE_COMPLETION_ONSTACK(comp);
482 struct virtio_scsi_target_state *tgt = vscsi->tgt[cmd->sc->device->id];
483 int ret = FAILED;
484
485 cmd->comp = &comp;
486 if (virtscsi_kick_cmd(tgt, &vscsi->ctrl_vq, cmd,
487 sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
488 GFP_NOIO) < 0)
489 goto out;
490
491 wait_for_completion(&comp);
492 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
493 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
494 ret = SUCCESS;
495
496 out:
497 mempool_free(cmd, virtscsi_cmd_pool);
498 return ret;
499 }
500
501 static int virtscsi_device_reset(struct scsi_cmnd *sc)
502 {
503 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
504 struct virtio_scsi_cmd *cmd;
505
506 sdev_printk(KERN_INFO, sc->device, "device reset\n");
507 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
508 if (!cmd)
509 return FAILED;
510
511 memset(cmd, 0, sizeof(*cmd));
512 cmd->sc = sc;
513 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
514 .type = VIRTIO_SCSI_T_TMF,
515 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
516 .lun[0] = 1,
517 .lun[1] = sc->device->id,
518 .lun[2] = (sc->device->lun >> 8) | 0x40,
519 .lun[3] = sc->device->lun & 0xff,
520 };
521 return virtscsi_tmf(vscsi, cmd);
522 }
523
524 static int virtscsi_abort(struct scsi_cmnd *sc)
525 {
526 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
527 struct virtio_scsi_cmd *cmd;
528
529 scmd_printk(KERN_INFO, sc, "abort\n");
530 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
531 if (!cmd)
532 return FAILED;
533
534 memset(cmd, 0, sizeof(*cmd));
535 cmd->sc = sc;
536 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
537 .type = VIRTIO_SCSI_T_TMF,
538 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
539 .lun[0] = 1,
540 .lun[1] = sc->device->id,
541 .lun[2] = (sc->device->lun >> 8) | 0x40,
542 .lun[3] = sc->device->lun & 0xff,
543 .tag = (unsigned long)sc,
544 };
545 return virtscsi_tmf(vscsi, cmd);
546 }
547
548 static struct scsi_host_template virtscsi_host_template = {
549 .module = THIS_MODULE,
550 .name = "Virtio SCSI HBA",
551 .proc_name = "virtio_scsi",
552 .queuecommand = virtscsi_queuecommand,
553 .this_id = -1,
554 .eh_abort_handler = virtscsi_abort,
555 .eh_device_reset_handler = virtscsi_device_reset,
556
557 .can_queue = 1024,
558 .dma_boundary = UINT_MAX,
559 .use_clustering = ENABLE_CLUSTERING,
560 };
561
562 #define virtscsi_config_get(vdev, fld) \
563 ({ \
564 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
565 vdev->config->get(vdev, \
566 offsetof(struct virtio_scsi_config, fld), \
567 &__val, sizeof(__val)); \
568 __val; \
569 })
570
571 #define virtscsi_config_set(vdev, fld, val) \
572 (void)({ \
573 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
574 vdev->config->set(vdev, \
575 offsetof(struct virtio_scsi_config, fld), \
576 &__val, sizeof(__val)); \
577 })
578
579 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
580 struct virtqueue *vq)
581 {
582 spin_lock_init(&virtscsi_vq->vq_lock);
583 virtscsi_vq->vq = vq;
584 }
585
586 static struct virtio_scsi_target_state *virtscsi_alloc_tgt(
587 struct virtio_device *vdev, int sg_elems)
588 {
589 struct virtio_scsi_target_state *tgt;
590 gfp_t gfp_mask = GFP_KERNEL;
591
592 /* We need extra sg elements at head and tail. */
593 tgt = kmalloc(sizeof(*tgt) + sizeof(tgt->sg[0]) * (sg_elems + 2),
594 gfp_mask);
595
596 if (!tgt)
597 return NULL;
598
599 spin_lock_init(&tgt->tgt_lock);
600 sg_init_table(tgt->sg, sg_elems + 2);
601 return tgt;
602 }
603
604 static void virtscsi_scan(struct virtio_device *vdev)
605 {
606 struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv;
607
608 scsi_scan_host(shost);
609 }
610
611 static void virtscsi_remove_vqs(struct virtio_device *vdev)
612 {
613 struct Scsi_Host *sh = virtio_scsi_host(vdev);
614 struct virtio_scsi *vscsi = shost_priv(sh);
615 u32 i, num_targets;
616
617 /* Stop all the virtqueues. */
618 vdev->config->reset(vdev);
619
620 num_targets = sh->max_id;
621 for (i = 0; i < num_targets; i++) {
622 kfree(vscsi->tgt[i]);
623 vscsi->tgt[i] = NULL;
624 }
625
626 vdev->config->del_vqs(vdev);
627 }
628
629 static int virtscsi_init(struct virtio_device *vdev,
630 struct virtio_scsi *vscsi, int num_targets)
631 {
632 int err;
633 struct virtqueue *vqs[3];
634 u32 i, sg_elems;
635
636 vq_callback_t *callbacks[] = {
637 virtscsi_ctrl_done,
638 virtscsi_event_done,
639 virtscsi_req_done
640 };
641 const char *names[] = {
642 "control",
643 "event",
644 "request"
645 };
646
647 /* Discover virtqueues and write information to configuration. */
648 err = vdev->config->find_vqs(vdev, 3, vqs, callbacks, names);
649 if (err)
650 return err;
651
652 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
653 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
654 virtscsi_init_vq(&vscsi->req_vq, vqs[2]);
655
656 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
657 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
658
659 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
660 virtscsi_kick_event_all(vscsi);
661
662 /* We need to know how many segments before we allocate. */
663 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
664
665 for (i = 0; i < num_targets; i++) {
666 vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
667 if (!vscsi->tgt[i]) {
668 err = -ENOMEM;
669 goto out;
670 }
671 }
672 err = 0;
673
674 out:
675 if (err)
676 virtscsi_remove_vqs(vdev);
677 return err;
678 }
679
680 static int __devinit virtscsi_probe(struct virtio_device *vdev)
681 {
682 struct Scsi_Host *shost;
683 struct virtio_scsi *vscsi;
684 int err;
685 u32 sg_elems, num_targets;
686 u32 cmd_per_lun;
687
688 /* Allocate memory and link the structs together. */
689 num_targets = virtscsi_config_get(vdev, max_target) + 1;
690 shost = scsi_host_alloc(&virtscsi_host_template,
691 sizeof(*vscsi)
692 + num_targets * sizeof(struct virtio_scsi_target_state));
693
694 if (!shost)
695 return -ENOMEM;
696
697 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
698 shost->sg_tablesize = sg_elems;
699 vscsi = shost_priv(shost);
700 vscsi->vdev = vdev;
701 vdev->priv = shost;
702
703 err = virtscsi_init(vdev, vscsi, num_targets);
704 if (err)
705 goto virtscsi_init_failed;
706
707 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
708 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
709 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
710
711 /* LUNs > 256 are reported with format 1, so they go in the range
712 * 16640-32767.
713 */
714 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
715 shost->max_id = num_targets;
716 shost->max_channel = 0;
717 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
718 err = scsi_add_host(shost, &vdev->dev);
719 if (err)
720 goto scsi_add_host_failed;
721 /*
722 * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
723 * after VIRTIO_CONFIG_S_DRIVER_OK has been set..
724 */
725 return 0;
726
727 scsi_add_host_failed:
728 vdev->config->del_vqs(vdev);
729 virtscsi_init_failed:
730 scsi_host_put(shost);
731 return err;
732 }
733
734 static void __devexit virtscsi_remove(struct virtio_device *vdev)
735 {
736 struct Scsi_Host *shost = virtio_scsi_host(vdev);
737 struct virtio_scsi *vscsi = shost_priv(shost);
738
739 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
740 virtscsi_cancel_event_work(vscsi);
741
742 scsi_remove_host(shost);
743
744 virtscsi_remove_vqs(vdev);
745 scsi_host_put(shost);
746 }
747
748 #ifdef CONFIG_PM
749 static int virtscsi_freeze(struct virtio_device *vdev)
750 {
751 virtscsi_remove_vqs(vdev);
752 return 0;
753 }
754
755 static int virtscsi_restore(struct virtio_device *vdev)
756 {
757 struct Scsi_Host *sh = virtio_scsi_host(vdev);
758 struct virtio_scsi *vscsi = shost_priv(sh);
759
760 return virtscsi_init(vdev, vscsi, sh->max_id);
761 }
762 #endif
763
764 static struct virtio_device_id id_table[] = {
765 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
766 { 0 },
767 };
768
769 static unsigned int features[] = {
770 VIRTIO_SCSI_F_HOTPLUG,
771 VIRTIO_SCSI_F_CHANGE,
772 };
773
774 static struct virtio_driver virtio_scsi_driver = {
775 .feature_table = features,
776 .feature_table_size = ARRAY_SIZE(features),
777 .driver.name = KBUILD_MODNAME,
778 .driver.owner = THIS_MODULE,
779 .id_table = id_table,
780 .probe = virtscsi_probe,
781 .scan = virtscsi_scan,
782 #ifdef CONFIG_PM
783 .freeze = virtscsi_freeze,
784 .restore = virtscsi_restore,
785 #endif
786 .remove = __devexit_p(virtscsi_remove),
787 };
788
789 static int __init init(void)
790 {
791 int ret = -ENOMEM;
792
793 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
794 if (!virtscsi_cmd_cache) {
795 printk(KERN_ERR "kmem_cache_create() for "
796 "virtscsi_cmd_cache failed\n");
797 goto error;
798 }
799
800
801 virtscsi_cmd_pool =
802 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
803 virtscsi_cmd_cache);
804 if (!virtscsi_cmd_pool) {
805 printk(KERN_ERR "mempool_create() for"
806 "virtscsi_cmd_pool failed\n");
807 goto error;
808 }
809 ret = register_virtio_driver(&virtio_scsi_driver);
810 if (ret < 0)
811 goto error;
812
813 return 0;
814
815 error:
816 if (virtscsi_cmd_pool) {
817 mempool_destroy(virtscsi_cmd_pool);
818 virtscsi_cmd_pool = NULL;
819 }
820 if (virtscsi_cmd_cache) {
821 kmem_cache_destroy(virtscsi_cmd_cache);
822 virtscsi_cmd_cache = NULL;
823 }
824 return ret;
825 }
826
827 static void __exit fini(void)
828 {
829 unregister_virtio_driver(&virtio_scsi_driver);
830 mempool_destroy(virtscsi_cmd_pool);
831 kmem_cache_destroy(virtscsi_cmd_cache);
832 }
833 module_init(init);
834 module_exit(fini);
835
836 MODULE_DEVICE_TABLE(virtio, id_table);
837 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
838 MODULE_LICENSE("GPL");
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