blob: 1b384311726897bff5ba3e1014a53a536eccc210 [file] [log] [blame]
Paolo Bonzini4fe74b12012-02-05 12:16:00 +01001/*
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
29/* Command queue element */
30struct virtio_scsi_cmd {
31 struct scsi_cmnd *sc;
32 struct completion *comp;
33 union {
34 struct virtio_scsi_cmd_req cmd;
35 struct virtio_scsi_ctrl_tmf_req tmf;
36 struct virtio_scsi_ctrl_an_req an;
37 } req;
38 union {
39 struct virtio_scsi_cmd_resp cmd;
40 struct virtio_scsi_ctrl_tmf_resp tmf;
41 struct virtio_scsi_ctrl_an_resp an;
42 struct virtio_scsi_event evt;
43 } resp;
44} ____cacheline_aligned_in_smp;
45
46/* Driver instance state */
47struct virtio_scsi {
48 /* Protects ctrl_vq, req_vq and sg[] */
49 spinlock_t vq_lock;
50
51 struct virtio_device *vdev;
52 struct virtqueue *ctrl_vq;
53 struct virtqueue *event_vq;
54 struct virtqueue *req_vq;
55
56 /* For sglist construction when adding commands to the virtqueue. */
57 struct scatterlist sg[];
58};
59
60static struct kmem_cache *virtscsi_cmd_cache;
61static mempool_t *virtscsi_cmd_pool;
62
63static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
64{
65 return vdev->priv;
66}
67
68static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
69{
70 if (!resid)
71 return;
72
73 if (!scsi_bidi_cmnd(sc)) {
74 scsi_set_resid(sc, resid);
75 return;
76 }
77
78 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
79 scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
80}
81
82/**
83 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
84 *
85 * Called with vq_lock held.
86 */
87static void virtscsi_complete_cmd(void *buf)
88{
89 struct virtio_scsi_cmd *cmd = buf;
90 struct scsi_cmnd *sc = cmd->sc;
91 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
92
93 dev_dbg(&sc->device->sdev_gendev,
94 "cmd %p response %u status %#02x sense_len %u\n",
95 sc, resp->response, resp->status, resp->sense_len);
96
97 sc->result = resp->status;
98 virtscsi_compute_resid(sc, resp->resid);
99 switch (resp->response) {
100 case VIRTIO_SCSI_S_OK:
101 set_host_byte(sc, DID_OK);
102 break;
103 case VIRTIO_SCSI_S_OVERRUN:
104 set_host_byte(sc, DID_ERROR);
105 break;
106 case VIRTIO_SCSI_S_ABORTED:
107 set_host_byte(sc, DID_ABORT);
108 break;
109 case VIRTIO_SCSI_S_BAD_TARGET:
110 set_host_byte(sc, DID_BAD_TARGET);
111 break;
112 case VIRTIO_SCSI_S_RESET:
113 set_host_byte(sc, DID_RESET);
114 break;
115 case VIRTIO_SCSI_S_BUSY:
116 set_host_byte(sc, DID_BUS_BUSY);
117 break;
118 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
119 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
120 break;
121 case VIRTIO_SCSI_S_TARGET_FAILURE:
122 set_host_byte(sc, DID_TARGET_FAILURE);
123 break;
124 case VIRTIO_SCSI_S_NEXUS_FAILURE:
125 set_host_byte(sc, DID_NEXUS_FAILURE);
126 break;
127 default:
128 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
129 resp->response);
130 /* fall through */
131 case VIRTIO_SCSI_S_FAILURE:
132 set_host_byte(sc, DID_ERROR);
133 break;
134 }
135
136 WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE);
137 if (sc->sense_buffer) {
138 memcpy(sc->sense_buffer, resp->sense,
139 min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
140 if (resp->sense_len)
141 set_driver_byte(sc, DRIVER_SENSE);
142 }
143
144 mempool_free(cmd, virtscsi_cmd_pool);
145 sc->scsi_done(sc);
146}
147
148static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
149{
150 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
151 struct virtio_scsi *vscsi = shost_priv(sh);
152 void *buf;
153 unsigned long flags;
154 unsigned int len;
155
156 spin_lock_irqsave(&vscsi->vq_lock, flags);
157
158 do {
159 virtqueue_disable_cb(vq);
160 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
161 fn(buf);
162 } while (!virtqueue_enable_cb(vq));
163
164 spin_unlock_irqrestore(&vscsi->vq_lock, flags);
165}
166
167static void virtscsi_req_done(struct virtqueue *vq)
168{
169 virtscsi_vq_done(vq, virtscsi_complete_cmd);
170};
171
172static void virtscsi_complete_free(void *buf)
173{
174 struct virtio_scsi_cmd *cmd = buf;
175
176 if (cmd->comp)
177 complete_all(cmd->comp);
Paolo Bonzinie4594bb2012-05-04 12:32:04 +0200178 else
179 mempool_free(cmd, virtscsi_cmd_pool);
Paolo Bonzini4fe74b12012-02-05 12:16:00 +0100180}
181
182static void virtscsi_ctrl_done(struct virtqueue *vq)
183{
184 virtscsi_vq_done(vq, virtscsi_complete_free);
185};
186
187static void virtscsi_event_done(struct virtqueue *vq)
188{
189 virtscsi_vq_done(vq, virtscsi_complete_free);
190};
191
192static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
193 struct scsi_data_buffer *sdb)
194{
195 struct sg_table *table = &sdb->table;
196 struct scatterlist *sg_elem;
197 unsigned int idx = *p_idx;
198 int i;
199
200 for_each_sg(table->sgl, sg_elem, table->nents, i)
201 sg_set_buf(&sg[idx++], sg_virt(sg_elem), sg_elem->length);
202
203 *p_idx = idx;
204}
205
206/**
207 * virtscsi_map_cmd - map a scsi_cmd to a virtqueue scatterlist
208 * @vscsi : virtio_scsi state
209 * @cmd : command structure
210 * @out_num : number of read-only elements
211 * @in_num : number of write-only elements
212 * @req_size : size of the request buffer
213 * @resp_size : size of the response buffer
214 *
215 * Called with vq_lock held.
216 */
217static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
218 struct virtio_scsi_cmd *cmd,
219 unsigned *out_num, unsigned *in_num,
220 size_t req_size, size_t resp_size)
221{
222 struct scsi_cmnd *sc = cmd->sc;
223 struct scatterlist *sg = vscsi->sg;
224 unsigned int idx = 0;
225
226 if (sc) {
227 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
228 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
229
230 /* TODO: check feature bit and fail if unsupported? */
231 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
232 }
233
234 /* Request header. */
235 sg_set_buf(&sg[idx++], &cmd->req, req_size);
236
237 /* Data-out buffer. */
238 if (sc && sc->sc_data_direction != DMA_FROM_DEVICE)
239 virtscsi_map_sgl(sg, &idx, scsi_out(sc));
240
241 *out_num = idx;
242
243 /* Response header. */
244 sg_set_buf(&sg[idx++], &cmd->resp, resp_size);
245
246 /* Data-in buffer */
247 if (sc && sc->sc_data_direction != DMA_TO_DEVICE)
248 virtscsi_map_sgl(sg, &idx, scsi_in(sc));
249
250 *in_num = idx - *out_num;
251}
252
253static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtqueue *vq,
254 struct virtio_scsi_cmd *cmd,
255 size_t req_size, size_t resp_size, gfp_t gfp)
256{
257 unsigned int out_num, in_num;
258 unsigned long flags;
259 int ret;
260
261 spin_lock_irqsave(&vscsi->vq_lock, flags);
262
263 virtscsi_map_cmd(vscsi, cmd, &out_num, &in_num, req_size, resp_size);
264
265 ret = virtqueue_add_buf(vq, vscsi->sg, out_num, in_num, cmd, gfp);
266 if (ret >= 0)
267 virtqueue_kick(vq);
268
269 spin_unlock_irqrestore(&vscsi->vq_lock, flags);
270 return ret;
271}
272
273static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
274{
275 struct virtio_scsi *vscsi = shost_priv(sh);
276 struct virtio_scsi_cmd *cmd;
277 int ret;
278
279 dev_dbg(&sc->device->sdev_gendev,
280 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
281
282 ret = SCSI_MLQUEUE_HOST_BUSY;
283 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC);
284 if (!cmd)
285 goto out;
286
287 memset(cmd, 0, sizeof(*cmd));
288 cmd->sc = sc;
289 cmd->req.cmd = (struct virtio_scsi_cmd_req){
290 .lun[0] = 1,
291 .lun[1] = sc->device->id,
292 .lun[2] = (sc->device->lun >> 8) | 0x40,
293 .lun[3] = sc->device->lun & 0xff,
294 .tag = (unsigned long)sc,
295 .task_attr = VIRTIO_SCSI_S_SIMPLE,
296 .prio = 0,
297 .crn = 0,
298 };
299
300 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
301 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
302
303 if (virtscsi_kick_cmd(vscsi, vscsi->req_vq, cmd,
304 sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
305 GFP_ATOMIC) >= 0)
306 ret = 0;
307
308out:
309 return ret;
310}
311
312static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
313{
314 DECLARE_COMPLETION_ONSTACK(comp);
Paolo Bonzinie4594bb2012-05-04 12:32:04 +0200315 int ret = FAILED;
Paolo Bonzini4fe74b12012-02-05 12:16:00 +0100316
317 cmd->comp = &comp;
Paolo Bonzinie4594bb2012-05-04 12:32:04 +0200318 if (virtscsi_kick_cmd(vscsi, vscsi->ctrl_vq, cmd,
319 sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
320 GFP_NOIO) < 0)
321 goto out;
Paolo Bonzini4fe74b12012-02-05 12:16:00 +0100322
323 wait_for_completion(&comp);
Paolo Bonzinie4594bb2012-05-04 12:32:04 +0200324 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
325 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
326 ret = SUCCESS;
Paolo Bonzini4fe74b12012-02-05 12:16:00 +0100327
Paolo Bonzinie4594bb2012-05-04 12:32:04 +0200328out:
329 mempool_free(cmd, virtscsi_cmd_pool);
330 return ret;
Paolo Bonzini4fe74b12012-02-05 12:16:00 +0100331}
332
333static int virtscsi_device_reset(struct scsi_cmnd *sc)
334{
335 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
336 struct virtio_scsi_cmd *cmd;
337
338 sdev_printk(KERN_INFO, sc->device, "device reset\n");
339 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
340 if (!cmd)
341 return FAILED;
342
343 memset(cmd, 0, sizeof(*cmd));
344 cmd->sc = sc;
345 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
346 .type = VIRTIO_SCSI_T_TMF,
347 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
348 .lun[0] = 1,
349 .lun[1] = sc->device->id,
350 .lun[2] = (sc->device->lun >> 8) | 0x40,
351 .lun[3] = sc->device->lun & 0xff,
352 };
353 return virtscsi_tmf(vscsi, cmd);
354}
355
356static int virtscsi_abort(struct scsi_cmnd *sc)
357{
358 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
359 struct virtio_scsi_cmd *cmd;
360
361 scmd_printk(KERN_INFO, sc, "abort\n");
362 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
363 if (!cmd)
364 return FAILED;
365
366 memset(cmd, 0, sizeof(*cmd));
367 cmd->sc = sc;
368 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
369 .type = VIRTIO_SCSI_T_TMF,
370 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
371 .lun[0] = 1,
372 .lun[1] = sc->device->id,
373 .lun[2] = (sc->device->lun >> 8) | 0x40,
374 .lun[3] = sc->device->lun & 0xff,
375 .tag = (unsigned long)sc,
376 };
377 return virtscsi_tmf(vscsi, cmd);
378}
379
380static struct scsi_host_template virtscsi_host_template = {
381 .module = THIS_MODULE,
382 .name = "Virtio SCSI HBA",
383 .proc_name = "virtio_scsi",
384 .queuecommand = virtscsi_queuecommand,
385 .this_id = -1,
386 .eh_abort_handler = virtscsi_abort,
387 .eh_device_reset_handler = virtscsi_device_reset,
388
389 .can_queue = 1024,
390 .dma_boundary = UINT_MAX,
391 .use_clustering = ENABLE_CLUSTERING,
392};
393
394#define virtscsi_config_get(vdev, fld) \
395 ({ \
396 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
397 vdev->config->get(vdev, \
398 offsetof(struct virtio_scsi_config, fld), \
399 &__val, sizeof(__val)); \
400 __val; \
401 })
402
403#define virtscsi_config_set(vdev, fld, val) \
404 (void)({ \
405 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
406 vdev->config->set(vdev, \
407 offsetof(struct virtio_scsi_config, fld), \
408 &__val, sizeof(__val)); \
409 })
410
411static int virtscsi_init(struct virtio_device *vdev,
412 struct virtio_scsi *vscsi)
413{
414 int err;
415 struct virtqueue *vqs[3];
416 vq_callback_t *callbacks[] = {
417 virtscsi_ctrl_done,
418 virtscsi_event_done,
419 virtscsi_req_done
420 };
421 const char *names[] = {
422 "control",
423 "event",
424 "request"
425 };
426
427 /* Discover virtqueues and write information to configuration. */
428 err = vdev->config->find_vqs(vdev, 3, vqs, callbacks, names);
429 if (err)
430 return err;
431
432 vscsi->ctrl_vq = vqs[0];
433 vscsi->event_vq = vqs[1];
434 vscsi->req_vq = vqs[2];
435
436 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
437 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
438 return 0;
439}
440
441static int __devinit virtscsi_probe(struct virtio_device *vdev)
442{
443 struct Scsi_Host *shost;
444 struct virtio_scsi *vscsi;
445 int err;
446 u32 sg_elems;
447 u32 cmd_per_lun;
448
449 /* We need to know how many segments before we allocate.
450 * We need an extra sg elements at head and tail.
451 */
452 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
453
454 /* Allocate memory and link the structs together. */
455 shost = scsi_host_alloc(&virtscsi_host_template,
456 sizeof(*vscsi) + sizeof(vscsi->sg[0]) * (sg_elems + 2));
457
458 if (!shost)
459 return -ENOMEM;
460
461 shost->sg_tablesize = sg_elems;
462 vscsi = shost_priv(shost);
463 vscsi->vdev = vdev;
464 vdev->priv = shost;
465
466 /* Random initializations. */
467 spin_lock_init(&vscsi->vq_lock);
468 sg_init_table(vscsi->sg, sg_elems + 2);
469
470 err = virtscsi_init(vdev, vscsi);
471 if (err)
472 goto virtscsi_init_failed;
473
474 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
475 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
476 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
477 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1;
478 shost->max_id = virtscsi_config_get(vdev, max_target) + 1;
479 shost->max_channel = 0;
480 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
481 err = scsi_add_host(shost, &vdev->dev);
482 if (err)
483 goto scsi_add_host_failed;
484
485 scsi_scan_host(shost);
486
487 return 0;
488
489scsi_add_host_failed:
490 vdev->config->del_vqs(vdev);
491virtscsi_init_failed:
492 scsi_host_put(shost);
493 return err;
494}
495
496static void virtscsi_remove_vqs(struct virtio_device *vdev)
497{
498 /* Stop all the virtqueues. */
499 vdev->config->reset(vdev);
500
501 vdev->config->del_vqs(vdev);
502}
503
504static void __devexit virtscsi_remove(struct virtio_device *vdev)
505{
506 struct Scsi_Host *shost = virtio_scsi_host(vdev);
507
508 scsi_remove_host(shost);
509
510 virtscsi_remove_vqs(vdev);
511 scsi_host_put(shost);
512}
513
514#ifdef CONFIG_PM
515static int virtscsi_freeze(struct virtio_device *vdev)
516{
517 virtscsi_remove_vqs(vdev);
518 return 0;
519}
520
521static int virtscsi_restore(struct virtio_device *vdev)
522{
523 struct Scsi_Host *sh = virtio_scsi_host(vdev);
524 struct virtio_scsi *vscsi = shost_priv(sh);
525
526 return virtscsi_init(vdev, vscsi);
527}
528#endif
529
530static struct virtio_device_id id_table[] = {
531 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
532 { 0 },
533};
534
535static struct virtio_driver virtio_scsi_driver = {
536 .driver.name = KBUILD_MODNAME,
537 .driver.owner = THIS_MODULE,
538 .id_table = id_table,
539 .probe = virtscsi_probe,
540#ifdef CONFIG_PM
541 .freeze = virtscsi_freeze,
542 .restore = virtscsi_restore,
543#endif
544 .remove = __devexit_p(virtscsi_remove),
545};
546
547static int __init init(void)
548{
549 int ret = -ENOMEM;
550
551 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
552 if (!virtscsi_cmd_cache) {
553 printk(KERN_ERR "kmem_cache_create() for "
554 "virtscsi_cmd_cache failed\n");
555 goto error;
556 }
557
558
559 virtscsi_cmd_pool =
560 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
561 virtscsi_cmd_cache);
562 if (!virtscsi_cmd_pool) {
563 printk(KERN_ERR "mempool_create() for"
564 "virtscsi_cmd_pool failed\n");
565 goto error;
566 }
567 ret = register_virtio_driver(&virtio_scsi_driver);
568 if (ret < 0)
569 goto error;
570
571 return 0;
572
573error:
574 if (virtscsi_cmd_pool) {
575 mempool_destroy(virtscsi_cmd_pool);
576 virtscsi_cmd_pool = NULL;
577 }
578 if (virtscsi_cmd_cache) {
579 kmem_cache_destroy(virtscsi_cmd_cache);
580 virtscsi_cmd_cache = NULL;
581 }
582 return ret;
583}
584
585static void __exit fini(void)
586{
587 unregister_virtio_driver(&virtio_scsi_driver);
588 mempool_destroy(virtscsi_cmd_pool);
589 kmem_cache_destroy(virtscsi_cmd_cache);
590}
591module_init(init);
592module_exit(fini);
593
594MODULE_DEVICE_TABLE(virtio, id_table);
595MODULE_DESCRIPTION("Virtio SCSI HBA driver");
596MODULE_LICENSE("GPL");