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virtio: rpmsg: make it clear that virtqueue_add_buf() no longer returns > 0
[deliverable/linux.git] / drivers / scsi / virtio_scsi.c
CommitLineData
4fe74b1c
PB		 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
365a7150 28#define VIRTIO_SCSI_EVENT_LEN 8
4fe74b1c
PB		 29
30/* Command queue element */
31struct 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
365a7150
CM		 47struct virtio_scsi_event_node {
48 struct virtio_scsi *vscsi;
49 struct virtio_scsi_event event;
50 struct work_struct work;
51};
52
139fe45a
PB		 53struct virtio_scsi_vq {
54 /* Protects vq */
55 spinlock_t vq_lock;
56
57 struct virtqueue *vq;
58};
59
2bd37f0f
PB		 60/* Per-target queue state */
61struct 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
4fe74b1c
PB		 69/* Driver instance state */
70struct virtio_scsi {
4fe74b1c 71 struct virtio_device *vdev;
2bd37f0f 72
139fe45a
PB		 73 struct virtio_scsi_vq ctrl_vq;
74 struct virtio_scsi_vq event_vq;
75 struct virtio_scsi_vq req_vq;
4fe74b1c 76
365a7150
CM		 77 /* Get some buffers ready for event vq */
78 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
79
2bd37f0f 80 struct virtio_scsi_target_state *tgt[];
4fe74b1c
PB		 81};
82
83static struct kmem_cache *virtscsi_cmd_cache;
84static mempool_t *virtscsi_cmd_pool;
85
86static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
87{
88 return vdev->priv;
89}
90
91static 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 */
110static 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
171static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
172{
4fe74b1c 173 void *buf;
4fe74b1c
PB		 174 unsigned int len;
175
4fe74b1c
PB		 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));
4fe74b1c
PB		 181}
182
183static void virtscsi_req_done(struct virtqueue *vq)
184{
139fe45a
PB		 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);
4fe74b1c 190 virtscsi_vq_done(vq, virtscsi_complete_cmd);
139fe45a 191 spin_unlock_irqrestore(&vscsi->req_vq.vq_lock, flags);
4fe74b1c
PB		 192};
193
194static void virtscsi_complete_free(void *buf)
195{
196 struct virtio_scsi_cmd *cmd = buf;
197
198 if (cmd->comp)
199 complete_all(cmd->comp);
e4594bb5
PB		 200 else
201 mempool_free(cmd, virtscsi_cmd_pool);
4fe74b1c
PB		 202}
203
204static void virtscsi_ctrl_done(struct virtqueue *vq)
205{
139fe45a
PB		 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);
4fe74b1c 211 virtscsi_vq_done(vq, virtscsi_complete_free);
139fe45a 212 spin_unlock_irqrestore(&vscsi->ctrl_vq.vq_lock, flags);
4fe74b1c
PB		 213};
214
365a7150
CM		 215static 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
2e9c9dfd 222 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
365a7150
CM		 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
235static 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
247static 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
255static 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
865b58c0
PB		 282static 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
365a7150
CM		 307static 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;
865b58c0
PB		 325 case VIRTIO_SCSI_T_PARAM_CHANGE:
326 virtscsi_handle_param_change(vscsi, event);
327 break;
365a7150
CM		 328 default:
329 pr_err("Unsupport virtio scsi event %x\n", event->event);
330 }
331 virtscsi_kick_event(vscsi, event_node);
332}
333
334static 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
4fe74b1c
PB		 342static void virtscsi_event_done(struct virtqueue *vq)
343{
139fe45a
PB		 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);
365a7150 349 virtscsi_vq_done(vq, virtscsi_complete_event);
139fe45a 350 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
4fe74b1c
PB		 351};
352
353static 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)
27e99ade 362 sg[idx++] = *sg_elem;
4fe74b1c
PB		 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 *
2bd37f0f 376 * Called with tgt_lock held.
4fe74b1c 377 */
2bd37f0f 378static void virtscsi_map_cmd(struct virtio_scsi_target_state *tgt,
4fe74b1c
PB		 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;
2bd37f0f 384 struct scatterlist *sg = tgt->sg;
4fe74b1c
PB		 385 unsigned int idx = 0;
386
4fe74b1c
PB		 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
2bd37f0f
PB		 406static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
407 struct virtio_scsi_vq *vq,
4fe74b1c
PB		 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
2bd37f0f
PB		 415 spin_lock_irqsave(&tgt->tgt_lock, flags);
416 virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
4fe74b1c 417
139fe45a 418 spin_lock(&vq->vq_lock);
2bd37f0f
PB		 419 ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
420 spin_unlock(&tgt->tgt_lock);
4fe74b1c 421 if (ret >= 0)
139fe45a
PB		 422 ret = virtqueue_kick_prepare(vq->vq);
423
bce750b1 424 spin_unlock_irqrestore(&vq->vq_lock, flags);
4fe74b1c 425
b5ee8f28 426 if (ret > 0)
139fe45a 427 virtqueue_notify(vq->vq);
4fe74b1c
PB		 428 return ret;
429}
430
431static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
432{
433 struct virtio_scsi *vscsi = shost_priv(sh);
2bd37f0f 434 struct virtio_scsi_target_state *tgt = vscsi->tgt[sc->device->id];
4fe74b1c
PB		 435 struct virtio_scsi_cmd *cmd;
436 int ret;
437
2bd37f0f
PB		 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
4fe74b1c
PB		 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
2bd37f0f 468 if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
4fe74b1c
PB		 469 sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
470 GFP_ATOMIC) >= 0)
471 ret = 0;
472
473out:
474 return ret;
475}
476
477static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
478{
479 DECLARE_COMPLETION_ONSTACK(comp);
2bd37f0f 480 struct virtio_scsi_target_state *tgt = vscsi->tgt[cmd->sc->device->id];
e4594bb5 481 int ret = FAILED;
4fe74b1c
PB		 482
483 cmd->comp = &comp;
2bd37f0f 484 if (virtscsi_kick_cmd(tgt, &vscsi->ctrl_vq, cmd,
e4594bb5
PB		 485 sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
486 GFP_NOIO) < 0)
487 goto out;
4fe74b1c
PB		 488
489 wait_for_completion(&comp);
e4594bb5
PB		 490 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
491 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
492 ret = SUCCESS;
4fe74b1c 493
e4594bb5
PB		 494out:
495 mempool_free(cmd, virtscsi_cmd_pool);
496 return ret;
4fe74b1c
PB		 497}
498
499static int virtscsi_device_reset(struct scsi_cmnd *sc)
500{
501 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
502 struct virtio_scsi_cmd *cmd;
503
504 sdev_printk(KERN_INFO, sc->device, "device reset\n");
505 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
506 if (!cmd)
507 return FAILED;
508
509 memset(cmd, 0, sizeof(*cmd));
510 cmd->sc = sc;
511 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
512 .type = VIRTIO_SCSI_T_TMF,
513 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
514 .lun[0] = 1,
515 .lun[1] = sc->device->id,
516 .lun[2] = (sc->device->lun >> 8) | 0x40,
517 .lun[3] = sc->device->lun & 0xff,
518 };
519 return virtscsi_tmf(vscsi, cmd);
520}
521
522static int virtscsi_abort(struct scsi_cmnd *sc)
523{
524 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
525 struct virtio_scsi_cmd *cmd;
526
527 scmd_printk(KERN_INFO, sc, "abort\n");
528 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
529 if (!cmd)
530 return FAILED;
531
532 memset(cmd, 0, sizeof(*cmd));
533 cmd->sc = sc;
534 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
535 .type = VIRTIO_SCSI_T_TMF,
536 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
537 .lun[0] = 1,
538 .lun[1] = sc->device->id,
539 .lun[2] = (sc->device->lun >> 8) | 0x40,
540 .lun[3] = sc->device->lun & 0xff,
541 .tag = (unsigned long)sc,
542 };
543 return virtscsi_tmf(vscsi, cmd);
544}
545
546static struct scsi_host_template virtscsi_host_template = {
547 .module = THIS_MODULE,
548 .name = "Virtio SCSI HBA",
549 .proc_name = "virtio_scsi",
550 .queuecommand = virtscsi_queuecommand,
551 .this_id = -1,
552 .eh_abort_handler = virtscsi_abort,
553 .eh_device_reset_handler = virtscsi_device_reset,
554
555 .can_queue = 1024,
556 .dma_boundary = UINT_MAX,
557 .use_clustering = ENABLE_CLUSTERING,
558};
559
560#define virtscsi_config_get(vdev, fld) \
561 ({ \
562 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
563 vdev->config->get(vdev, \
564 offsetof(struct virtio_scsi_config, fld), \
565 &__val, sizeof(__val)); \
566 __val; \
567 })
568
569#define virtscsi_config_set(vdev, fld, val) \
570 (void)({ \
571 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
572 vdev->config->set(vdev, \
573 offsetof(struct virtio_scsi_config, fld), \
574 &__val, sizeof(__val)); \
575 })
576
139fe45a
PB		 577static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
578 struct virtqueue *vq)
579{
580 spin_lock_init(&virtscsi_vq->vq_lock);
581 virtscsi_vq->vq = vq;
582}
583
2bd37f0f
PB		 584static struct virtio_scsi_target_state *virtscsi_alloc_tgt(
585 struct virtio_device *vdev, int sg_elems)
586{
587 struct virtio_scsi_target_state *tgt;
588 gfp_t gfp_mask = GFP_KERNEL;
589
590 /* We need extra sg elements at head and tail. */
591 tgt = kmalloc(sizeof(*tgt) + sizeof(tgt->sg[0]) * (sg_elems + 2),
592 gfp_mask);
593
594 if (!tgt)
595 return NULL;
596
597 spin_lock_init(&tgt->tgt_lock);
598 sg_init_table(tgt->sg, sg_elems + 2);
599 return tgt;
600}
601
59057fbc
NB		 602static void virtscsi_scan(struct virtio_device *vdev)
603{
604 struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv;
605
606 scsi_scan_host(shost);
607}
608
2bd37f0f
PB		 609static void virtscsi_remove_vqs(struct virtio_device *vdev)
610{
611 struct Scsi_Host *sh = virtio_scsi_host(vdev);
612 struct virtio_scsi *vscsi = shost_priv(sh);
613 u32 i, num_targets;
614
615 /* Stop all the virtqueues. */
616 vdev->config->reset(vdev);
617
618 num_targets = sh->max_id;
619 for (i = 0; i < num_targets; i++) {
620 kfree(vscsi->tgt[i]);
621 vscsi->tgt[i] = NULL;
622 }
623
624 vdev->config->del_vqs(vdev);
625}
626
4fe74b1c 627static int virtscsi_init(struct virtio_device *vdev,
2bd37f0f 628 struct virtio_scsi *vscsi, int num_targets)
4fe74b1c
PB		 629{
630 int err;
631 struct virtqueue *vqs[3];
2bd37f0f
PB		 632 u32 i, sg_elems;
633
4fe74b1c
PB		 634 vq_callback_t *callbacks[] = {
635 virtscsi_ctrl_done,
636 virtscsi_event_done,
637 virtscsi_req_done
638 };
639 const char *names[] = {
640 "control",
641 "event",
642 "request"
643 };
644
645 /* Discover virtqueues and write information to configuration. */
646 err = vdev->config->find_vqs(vdev, 3, vqs, callbacks, names);
647 if (err)
648 return err;
649
139fe45a
PB		 650 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
651 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
652 virtscsi_init_vq(&vscsi->req_vq, vqs[2]);
4fe74b1c
PB		 653
654 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
655 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
2bd37f0f 656
365a7150
CM		 657 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
658 virtscsi_kick_event_all(vscsi);
659
2bd37f0f
PB		 660 /* We need to know how many segments before we allocate. */
661 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
662
663 for (i = 0; i < num_targets; i++) {
664 vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
665 if (!vscsi->tgt[i]) {
666 err = -ENOMEM;
667 goto out;
668 }
669 }
670 err = 0;
671
672out:
673 if (err)
674 virtscsi_remove_vqs(vdev);
675 return err;
4fe74b1c
PB		 676}
677
678static int __devinit virtscsi_probe(struct virtio_device *vdev)
679{
680 struct Scsi_Host *shost;
681 struct virtio_scsi *vscsi;
682 int err;
2bd37f0f 683 u32 sg_elems, num_targets;
4fe74b1c
PB		 684 u32 cmd_per_lun;
685
4fe74b1c 686 /* Allocate memory and link the structs together. */
2bd37f0f 687 num_targets = virtscsi_config_get(vdev, max_target) + 1;
4fe74b1c 688 shost = scsi_host_alloc(&virtscsi_host_template,
2bd37f0f
PB		 689 sizeof(*vscsi)
690 + num_targets * sizeof(struct virtio_scsi_target_state));
4fe74b1c
PB		 691
692 if (!shost)
693 return -ENOMEM;
694
2bd37f0f 695 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
4fe74b1c
PB		 696 shost->sg_tablesize = sg_elems;
697 vscsi = shost_priv(shost);
698 vscsi->vdev = vdev;
699 vdev->priv = shost;
700
2bd37f0f 701 err = virtscsi_init(vdev, vscsi, num_targets);
4fe74b1c
PB		 702 if (err)
703 goto virtscsi_init_failed;
704
705 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
706 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
707 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
9da5f5ac
PB		 708
709 /* LUNs > 256 are reported with format 1, so they go in the range
710 * 16640-32767.
711 */
712 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
2bd37f0f 713 shost->max_id = num_targets;
4fe74b1c
PB		 714 shost->max_channel = 0;
715 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
716 err = scsi_add_host(shost, &vdev->dev);
717 if (err)
718 goto scsi_add_host_failed;
59057fbc
NB		 719 /*
720 * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
721 * after VIRTIO_CONFIG_S_DRIVER_OK has been set..
722 */
4fe74b1c
PB		 723 return 0;
724
725scsi_add_host_failed:
726 vdev->config->del_vqs(vdev);
727virtscsi_init_failed:
728 scsi_host_put(shost);
729 return err;
730}
731
4fe74b1c
PB		 732static void __devexit virtscsi_remove(struct virtio_device *vdev)
733{
734 struct Scsi_Host *shost = virtio_scsi_host(vdev);
365a7150
CM		 735 struct virtio_scsi *vscsi = shost_priv(shost);
736
737 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
738 virtscsi_cancel_event_work(vscsi);
4fe74b1c
PB		 739
740 scsi_remove_host(shost);
741
742 virtscsi_remove_vqs(vdev);
743 scsi_host_put(shost);
744}
745
746#ifdef CONFIG_PM
747static int virtscsi_freeze(struct virtio_device *vdev)
748{
749 virtscsi_remove_vqs(vdev);
750 return 0;
751}
752
753static int virtscsi_restore(struct virtio_device *vdev)
754{
755 struct Scsi_Host *sh = virtio_scsi_host(vdev);
756 struct virtio_scsi *vscsi = shost_priv(sh);
757
2bd37f0f 758 return virtscsi_init(vdev, vscsi, sh->max_id);
4fe74b1c
PB		 759}
760#endif
761
762static struct virtio_device_id id_table[] = {
763 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
764 { 0 },
765};
766
365a7150 767static unsigned int features[] = {
865b58c0
PB		 768 VIRTIO_SCSI_F_HOTPLUG,
769 VIRTIO_SCSI_F_CHANGE,
365a7150
CM		 770};
771
4fe74b1c 772static struct virtio_driver virtio_scsi_driver = {
365a7150
CM		 773 .feature_table = features,
774 .feature_table_size = ARRAY_SIZE(features),
4fe74b1c
PB		 775 .driver.name = KBUILD_MODNAME,
776 .driver.owner = THIS_MODULE,
777 .id_table = id_table,
778 .probe = virtscsi_probe,
59057fbc 779 .scan = virtscsi_scan,
4fe74b1c
PB		 780#ifdef CONFIG_PM
781 .freeze = virtscsi_freeze,
782 .restore = virtscsi_restore,
783#endif
784 .remove = __devexit_p(virtscsi_remove),
785};
786
787static int __init init(void)
788{
789 int ret = -ENOMEM;
790
791 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
792 if (!virtscsi_cmd_cache) {
793 printk(KERN_ERR "kmem_cache_create() for "
794 "virtscsi_cmd_cache failed\n");
795 goto error;
796 }
797
798
799 virtscsi_cmd_pool =
800 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
801 virtscsi_cmd_cache);
802 if (!virtscsi_cmd_pool) {
803 printk(KERN_ERR "mempool_create() for"
804 "virtscsi_cmd_pool failed\n");
805 goto error;
806 }
807 ret = register_virtio_driver(&virtio_scsi_driver);
808 if (ret < 0)
809 goto error;
810
811 return 0;
812
813error:
814 if (virtscsi_cmd_pool) {
815 mempool_destroy(virtscsi_cmd_pool);
816 virtscsi_cmd_pool = NULL;
817 }
818 if (virtscsi_cmd_cache) {
819 kmem_cache_destroy(virtscsi_cmd_cache);
820 virtscsi_cmd_cache = NULL;
821 }
822 return ret;
823}
824
825static void __exit fini(void)
826{
827 unregister_virtio_driver(&virtio_scsi_driver);
828 mempool_destroy(virtscsi_cmd_pool);
829 kmem_cache_destroy(virtscsi_cmd_cache);
830}
831module_init(init);
832module_exit(fini);
833
834MODULE_DEVICE_TABLE(virtio, id_table);
835MODULE_DESCRIPTION("Virtio SCSI HBA driver");
836MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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