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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / scsi / virtio_scsi.c
blobbfec84aacd90b6c812659418f27f2ebcd009099b
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Virtio SCSI HBA driver
4 *
5 * Copyright IBM Corp. 2010
6 * Copyright Red Hat, Inc. 2011
7 *
8 * Authors:
9 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
10 * Paolo Bonzini <pbonzini@redhat.com>
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/mempool.h>
18 #include <linux/interrupt.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 <linux/cpu.h>
24 #include <linux/blkdev.h>
25 #include <scsi/scsi_host.h>
26 #include <scsi/scsi_device.h>
27 #include <scsi/scsi_cmnd.h>
28 #include <scsi/scsi_tcq.h>
29 #include <scsi/scsi_devinfo.h>
30 #include <linux/seqlock.h>
31 #include <linux/blk-mq-virtio.h>
32
33 #include "sd.h"
34
35 #define VIRTIO_SCSI_MEMPOOL_SZ 64
36 #define VIRTIO_SCSI_EVENT_LEN 8
37 #define VIRTIO_SCSI_VQ_BASE 2
38
39 /* Command queue element */
40 struct virtio_scsi_cmd {
41 struct scsi_cmnd *sc;
42 struct completion *comp;
43 union {
44 struct virtio_scsi_cmd_req cmd;
45 struct virtio_scsi_cmd_req_pi cmd_pi;
46 struct virtio_scsi_ctrl_tmf_req tmf;
47 struct virtio_scsi_ctrl_an_req an;
48 } req;
49 union {
50 struct virtio_scsi_cmd_resp cmd;
51 struct virtio_scsi_ctrl_tmf_resp tmf;
52 struct virtio_scsi_ctrl_an_resp an;
53 struct virtio_scsi_event evt;
54 } resp;
55 } ____cacheline_aligned_in_smp;
56
57 struct virtio_scsi_event_node {
58 struct virtio_scsi *vscsi;
59 struct virtio_scsi_event event;
60 struct work_struct work;
61 };
62
63 struct virtio_scsi_vq {
64 /* Protects vq */
65 spinlock_t vq_lock;
66
67 struct virtqueue *vq;
68 };
69
70 /* Driver instance state */
71 struct virtio_scsi {
72 struct virtio_device *vdev;
73
74 /* Get some buffers ready for event vq */
75 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
76
77 u32 num_queues;
78
79 struct hlist_node node;
80
81 /* Protected by event_vq lock */
82 bool stop_events;
83
84 struct virtio_scsi_vq ctrl_vq;
85 struct virtio_scsi_vq event_vq;
86 struct virtio_scsi_vq req_vqs[];
87 };
88
89 static struct kmem_cache *virtscsi_cmd_cache;
90 static mempool_t *virtscsi_cmd_pool;
91
92 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
93 {
94 return vdev->priv;
95 }
96
97 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
98 {
99 if (resid)
100 scsi_set_resid(sc, resid);
101 }
102
103 /**
104 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
105 *
106 * Called with vq_lock held.
107 */
108 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
109 {
110 struct virtio_scsi_cmd *cmd = buf;
111 struct scsi_cmnd *sc = cmd->sc;
112 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
113
114 dev_dbg(&sc->device->sdev_gendev,
115 "cmd %p response %u status %#02x sense_len %u\n",
116 sc, resp->response, resp->status, resp->sense_len);
117
118 sc->result = resp->status;
119 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid));
120 switch (resp->response) {
121 case VIRTIO_SCSI_S_OK:
122 set_host_byte(sc, DID_OK);
123 break;
124 case VIRTIO_SCSI_S_OVERRUN:
125 set_host_byte(sc, DID_ERROR);
126 break;
127 case VIRTIO_SCSI_S_ABORTED:
128 set_host_byte(sc, DID_ABORT);
129 break;
130 case VIRTIO_SCSI_S_BAD_TARGET:
131 set_host_byte(sc, DID_BAD_TARGET);
132 break;
133 case VIRTIO_SCSI_S_RESET:
134 set_host_byte(sc, DID_RESET);
135 break;
136 case VIRTIO_SCSI_S_BUSY:
137 set_host_byte(sc, DID_BUS_BUSY);
138 break;
139 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
140 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
141 break;
142 case VIRTIO_SCSI_S_TARGET_FAILURE:
143 set_host_byte(sc, DID_TARGET_FAILURE);
144 break;
145 case VIRTIO_SCSI_S_NEXUS_FAILURE:
146 set_host_byte(sc, DID_NEXUS_FAILURE);
147 break;
148 default:
149 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
150 resp->response);
151 /* fall through */
152 case VIRTIO_SCSI_S_FAILURE:
153 set_host_byte(sc, DID_ERROR);
154 break;
155 }
156
157 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
158 VIRTIO_SCSI_SENSE_SIZE);
159 if (sc->sense_buffer) {
160 memcpy(sc->sense_buffer, resp->sense,
161 min_t(u32,
162 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
163 VIRTIO_SCSI_SENSE_SIZE));
164 if (resp->sense_len)
165 set_driver_byte(sc, DRIVER_SENSE);
166 }
167
168 sc->scsi_done(sc);
169 }
170
171 static void virtscsi_vq_done(struct virtio_scsi *vscsi,
172 struct virtio_scsi_vq *virtscsi_vq,
173 void (*fn)(struct virtio_scsi *vscsi, void *buf))
174 {
175 void *buf;
176 unsigned int len;
177 unsigned long flags;
178 struct virtqueue *vq = virtscsi_vq->vq;
179
180 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
181 do {
182 virtqueue_disable_cb(vq);
183 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
184 fn(vscsi, buf);
185
186 if (unlikely(virtqueue_is_broken(vq)))
187 break;
188 } while (!virtqueue_enable_cb(vq));
189 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
190 }
191
192 static void virtscsi_req_done(struct virtqueue *vq)
193 {
194 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
195 struct virtio_scsi *vscsi = shost_priv(sh);
196 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
197 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
198
199 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
200 };
201
202 static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
203 {
204 int i, num_vqs;
205
206 num_vqs = vscsi->num_queues;
207 for (i = 0; i < num_vqs; i++)
208 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
209 virtscsi_complete_cmd);
210 }
211
212 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
213 {
214 struct virtio_scsi_cmd *cmd = buf;
215
216 if (cmd->comp)
217 complete(cmd->comp);
218 }
219
220 static void virtscsi_ctrl_done(struct virtqueue *vq)
221 {
222 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
223 struct virtio_scsi *vscsi = shost_priv(sh);
224
225 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
226 };
227
228 static void virtscsi_handle_event(struct work_struct *work);
229
230 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
231 struct virtio_scsi_event_node *event_node)
232 {
233 int err;
234 struct scatterlist sg;
235 unsigned long flags;
236
237 INIT_WORK(&event_node->work, virtscsi_handle_event);
238 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
239
240 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
241
242 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
243 GFP_ATOMIC);
244 if (!err)
245 virtqueue_kick(vscsi->event_vq.vq);
246
247 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
248
249 return err;
250 }
251
252 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
253 {
254 int i;
255
256 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
257 vscsi->event_list[i].vscsi = vscsi;
258 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
259 }
260
261 return 0;
262 }
263
264 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
265 {
266 int i;
267
268 /* Stop scheduling work before calling cancel_work_sync. */
269 spin_lock_irq(&vscsi->event_vq.vq_lock);
270 vscsi->stop_events = true;
271 spin_unlock_irq(&vscsi->event_vq.vq_lock);
272
273 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
274 cancel_work_sync(&vscsi->event_list[i].work);
275 }
276
277 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
278 struct virtio_scsi_event *event)
279 {
280 struct scsi_device *sdev;
281 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
282 unsigned int target = event->lun[1];
283 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
284
285 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
286 case VIRTIO_SCSI_EVT_RESET_RESCAN:
287 scsi_add_device(shost, 0, target, lun);
288 break;
289 case VIRTIO_SCSI_EVT_RESET_REMOVED:
290 sdev = scsi_device_lookup(shost, 0, target, lun);
291 if (sdev) {
292 scsi_remove_device(sdev);
293 scsi_device_put(sdev);
294 } else {
295 pr_err("SCSI device %d 0 %d %d not found\n",
296 shost->host_no, target, lun);
297 }
298 break;
299 default:
300 pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
301 }
302 }
303
304 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
305 struct virtio_scsi_event *event)
306 {
307 struct scsi_device *sdev;
308 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
309 unsigned int target = event->lun[1];
310 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
311 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255;
312 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8;
313
314 sdev = scsi_device_lookup(shost, 0, target, lun);
315 if (!sdev) {
316 pr_err("SCSI device %d 0 %d %d not found\n",
317 shost->host_no, target, lun);
318 return;
319 }
320
321 /* Handle "Parameters changed", "Mode parameters changed", and
322 "Capacity data has changed". */
323 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
324 scsi_rescan_device(&sdev->sdev_gendev);
325
326 scsi_device_put(sdev);
327 }
328
329 static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
330 {
331 struct scsi_device *sdev;
332 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
333 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
334 int result, inquiry_len, inq_result_len = 256;
335 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
336
337 shost_for_each_device(sdev, shost) {
338 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
339
340 memset(scsi_cmd, 0, sizeof(scsi_cmd));
341 scsi_cmd[0] = INQUIRY;
342 scsi_cmd[4] = (unsigned char) inquiry_len;
343
344 memset(inq_result, 0, inq_result_len);
345
346 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
347 inq_result, inquiry_len, NULL,
348 SD_TIMEOUT, SD_MAX_RETRIES, NULL);
349
350 if (result == 0 && inq_result[0] >> 5) {
351 /* PQ indicates the LUN is not attached */
352 scsi_remove_device(sdev);
353 }
354 }
355
356 kfree(inq_result);
357 }
358
359 static void virtscsi_handle_event(struct work_struct *work)
360 {
361 struct virtio_scsi_event_node *event_node =
362 container_of(work, struct virtio_scsi_event_node, work);
363 struct virtio_scsi *vscsi = event_node->vscsi;
364 struct virtio_scsi_event *event = &event_node->event;
365
366 if (event->event &
367 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
368 event->event &= ~cpu_to_virtio32(vscsi->vdev,
369 VIRTIO_SCSI_T_EVENTS_MISSED);
370 virtscsi_rescan_hotunplug(vscsi);
371 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
372 }
373
374 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
375 case VIRTIO_SCSI_T_NO_EVENT:
376 break;
377 case VIRTIO_SCSI_T_TRANSPORT_RESET:
378 virtscsi_handle_transport_reset(vscsi, event);
379 break;
380 case VIRTIO_SCSI_T_PARAM_CHANGE:
381 virtscsi_handle_param_change(vscsi, event);
382 break;
383 default:
384 pr_err("Unsupport virtio scsi event %x\n", event->event);
385 }
386 virtscsi_kick_event(vscsi, event_node);
387 }
388
389 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
390 {
391 struct virtio_scsi_event_node *event_node = buf;
392
393 if (!vscsi->stop_events)
394 queue_work(system_freezable_wq, &event_node->work);
395 }
396
397 static void virtscsi_event_done(struct virtqueue *vq)
398 {
399 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
400 struct virtio_scsi *vscsi = shost_priv(sh);
401
402 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
403 };
404
405 static int __virtscsi_add_cmd(struct virtqueue *vq,
406 struct virtio_scsi_cmd *cmd,
407 size_t req_size, size_t resp_size)
408 {
409 struct scsi_cmnd *sc = cmd->sc;
410 struct scatterlist *sgs[6], req, resp;
411 struct sg_table *out, *in;
412 unsigned out_num = 0, in_num = 0;
413
414 out = in = NULL;
415
416 if (sc && sc->sc_data_direction != DMA_NONE) {
417 if (sc->sc_data_direction != DMA_FROM_DEVICE)
418 out = &sc->sdb.table;
419 if (sc->sc_data_direction != DMA_TO_DEVICE)
420 in = &sc->sdb.table;
421 }
422
423 /* Request header. */
424 sg_init_one(&req, &cmd->req, req_size);
425 sgs[out_num++] = &req;
426
427 /* Data-out buffer. */
428 if (out) {
429 /* Place WRITE protection SGLs before Data OUT payload */
430 if (scsi_prot_sg_count(sc))
431 sgs[out_num++] = scsi_prot_sglist(sc);
432 sgs[out_num++] = out->sgl;
433 }
434
435 /* Response header. */
436 sg_init_one(&resp, &cmd->resp, resp_size);
437 sgs[out_num + in_num++] = &resp;
438
439 /* Data-in buffer */
440 if (in) {
441 /* Place READ protection SGLs before Data IN payload */
442 if (scsi_prot_sg_count(sc))
443 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
444 sgs[out_num + in_num++] = in->sgl;
445 }
446
447 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
448 }
449
450 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
451 {
452 bool needs_kick;
453 unsigned long flags;
454
455 spin_lock_irqsave(&vq->vq_lock, flags);
456 needs_kick = virtqueue_kick_prepare(vq->vq);
457 spin_unlock_irqrestore(&vq->vq_lock, flags);
458
459 if (needs_kick)
460 virtqueue_notify(vq->vq);
461 }
462
463 /**
464 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
465 * @vq : the struct virtqueue we're talking about
466 * @cmd : command structure
467 * @req_size : size of the request buffer
468 * @resp_size : size of the response buffer
469 * @kick : whether to kick the virtqueue immediately
470 */
471 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
472 struct virtio_scsi_cmd *cmd,
473 size_t req_size, size_t resp_size,
474 bool kick)
475 {
476 unsigned long flags;
477 int err;
478 bool needs_kick = false;
479
480 spin_lock_irqsave(&vq->vq_lock, flags);
481 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
482 if (!err && kick)
483 needs_kick = virtqueue_kick_prepare(vq->vq);
484
485 spin_unlock_irqrestore(&vq->vq_lock, flags);
486
487 if (needs_kick)
488 virtqueue_notify(vq->vq);
489 return err;
490 }
491
492 static void virtio_scsi_init_hdr(struct virtio_device *vdev,
493 struct virtio_scsi_cmd_req *cmd,
494 struct scsi_cmnd *sc)
495 {
496 cmd->lun[0] = 1;
497 cmd->lun[1] = sc->device->id;
498 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
499 cmd->lun[3] = sc->device->lun & 0xff;
500 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
501 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
502 cmd->prio = 0;
503 cmd->crn = 0;
504 }
505
506 #ifdef CONFIG_BLK_DEV_INTEGRITY
507 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
508 struct virtio_scsi_cmd_req_pi *cmd_pi,
509 struct scsi_cmnd *sc)
510 {
511 struct request *rq = sc->request;
512 struct blk_integrity *bi;
513
514 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
515
516 if (!rq || !scsi_prot_sg_count(sc))
517 return;
518
519 bi = blk_get_integrity(rq->rq_disk);
520
521 if (sc->sc_data_direction == DMA_TO_DEVICE)
522 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
523 bio_integrity_bytes(bi,
524 blk_rq_sectors(rq)));
525 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
526 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
527 bio_integrity_bytes(bi,
528 blk_rq_sectors(rq)));
529 }
530 #endif
531
532 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
533 struct scsi_cmnd *sc)
534 {
535 u32 tag = blk_mq_unique_tag(sc->request);
536 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
537
538 return &vscsi->req_vqs[hwq];
539 }
540
541 static int virtscsi_queuecommand(struct Scsi_Host *shost,
542 struct scsi_cmnd *sc)
543 {
544 struct virtio_scsi *vscsi = shost_priv(shost);
545 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
546 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
547 bool kick;
548 unsigned long flags;
549 int req_size;
550 int ret;
551
552 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
553
554 /* TODO: check feature bit and fail if unsupported? */
555 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
556
557 dev_dbg(&sc->device->sdev_gendev,
558 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
559
560 cmd->sc = sc;
561
562 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
563
564 #ifdef CONFIG_BLK_DEV_INTEGRITY
565 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
566 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
567 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
568 req_size = sizeof(cmd->req.cmd_pi);
569 } else
570 #endif
571 {
572 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
573 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
574 req_size = sizeof(cmd->req.cmd);
575 }
576
577 kick = (sc->flags & SCMD_LAST) != 0;
578 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick);
579 if (ret == -EIO) {
580 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
581 spin_lock_irqsave(&req_vq->vq_lock, flags);
582 virtscsi_complete_cmd(vscsi, cmd);
583 spin_unlock_irqrestore(&req_vq->vq_lock, flags);
584 } else if (ret != 0) {
585 return SCSI_MLQUEUE_HOST_BUSY;
586 }
587 return 0;
588 }
589
590 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
591 {
592 DECLARE_COMPLETION_ONSTACK(comp);
593 int ret = FAILED;
594
595 cmd->comp = &comp;
596 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd,
597 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0)
598 goto out;
599
600 wait_for_completion(&comp);
601 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
602 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
603 ret = SUCCESS;
604
605 /*
606 * The spec guarantees that all requests related to the TMF have
607 * been completed, but the callback might not have run yet if
608 * we're using independent interrupts (e.g. MSI). Poll the
609 * virtqueues once.
610 *
611 * In the abort case, sc->scsi_done will do nothing, because
612 * the block layer must have detected a timeout and as a result
613 * REQ_ATOM_COMPLETE has been set.
614 */
615 virtscsi_poll_requests(vscsi);
616
617 out:
618 mempool_free(cmd, virtscsi_cmd_pool);
619 return ret;
620 }
621
622 static int virtscsi_device_reset(struct scsi_cmnd *sc)
623 {
624 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
625 struct virtio_scsi_cmd *cmd;
626
627 sdev_printk(KERN_INFO, sc->device, "device reset\n");
628 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
629 if (!cmd)
630 return FAILED;
631
632 memset(cmd, 0, sizeof(*cmd));
633 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
634 .type = VIRTIO_SCSI_T_TMF,
635 .subtype = cpu_to_virtio32(vscsi->vdev,
636 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
637 .lun[0] = 1,
638 .lun[1] = sc->device->id,
639 .lun[2] = (sc->device->lun >> 8) | 0x40,
640 .lun[3] = sc->device->lun & 0xff,
641 };
642 return virtscsi_tmf(vscsi, cmd);
643 }
644
645 static int virtscsi_device_alloc(struct scsi_device *sdevice)
646 {
647 /*
648 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
649 * may have transfer limits which come from the host SCSI
650 * controller or something on the host side other than the
651 * target itself.
652 *
653 * To make this work properly, the hypervisor can adjust the
654 * target's VPD information to advertise these limits. But
655 * for that to work, the guest has to look at the VPD pages,
656 * which we won't do by default if it is an SPC-2 device, even
657 * if it does actually support it.
658 *
659 * So, set the blist to always try to read the VPD pages.
660 */
661 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
662
663 return 0;
664 }
665
666
667 /**
668 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
669 * @sdev: Virtscsi target whose queue depth to change
670 * @qdepth: New queue depth
671 */
672 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
673 {
674 struct Scsi_Host *shost = sdev->host;
675 int max_depth = shost->cmd_per_lun;
676
677 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
678 }
679
680 static int virtscsi_abort(struct scsi_cmnd *sc)
681 {
682 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
683 struct virtio_scsi_cmd *cmd;
684
685 scmd_printk(KERN_INFO, sc, "abort\n");
686 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
687 if (!cmd)
688 return FAILED;
689
690 memset(cmd, 0, sizeof(*cmd));
691 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
692 .type = VIRTIO_SCSI_T_TMF,
693 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
694 .lun[0] = 1,
695 .lun[1] = sc->device->id,
696 .lun[2] = (sc->device->lun >> 8) | 0x40,
697 .lun[3] = sc->device->lun & 0xff,
698 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
699 };
700 return virtscsi_tmf(vscsi, cmd);
701 }
702
703 static int virtscsi_map_queues(struct Scsi_Host *shost)
704 {
705 struct virtio_scsi *vscsi = shost_priv(shost);
706 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
707
708 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2);
709 }
710
711 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
712 {
713 struct virtio_scsi *vscsi = shost_priv(shost);
714
715 virtscsi_kick_vq(&vscsi->req_vqs[hwq]);
716 }
717
718 /*
719 * The host guarantees to respond to each command, although I/O
720 * latencies might be higher than on bare metal. Reset the timer
721 * unconditionally to give the host a chance to perform EH.
722 */
723 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
724 {
725 return BLK_EH_RESET_TIMER;
726 }
727
728 static struct scsi_host_template virtscsi_host_template = {
729 .module = THIS_MODULE,
730 .name = "Virtio SCSI HBA",
731 .proc_name = "virtio_scsi",
732 .this_id = -1,
733 .cmd_size = sizeof(struct virtio_scsi_cmd),
734 .queuecommand = virtscsi_queuecommand,
735 .commit_rqs = virtscsi_commit_rqs,
736 .change_queue_depth = virtscsi_change_queue_depth,
737 .eh_abort_handler = virtscsi_abort,
738 .eh_device_reset_handler = virtscsi_device_reset,
739 .eh_timed_out = virtscsi_eh_timed_out,
740 .slave_alloc = virtscsi_device_alloc,
741
742 .dma_boundary = UINT_MAX,
743 .map_queues = virtscsi_map_queues,
744 .track_queue_depth = 1,
745 .force_blk_mq = 1,
746 };
747
748 #define virtscsi_config_get(vdev, fld) \
749 ({ \
750 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
751 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
752 __val; \
753 })
754
755 #define virtscsi_config_set(vdev, fld, val) \
756 do { \
757 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
758 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
759 } while(0)
760
761 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
762 struct virtqueue *vq)
763 {
764 spin_lock_init(&virtscsi_vq->vq_lock);
765 virtscsi_vq->vq = vq;
766 }
767
768 static void virtscsi_remove_vqs(struct virtio_device *vdev)
769 {
770 /* Stop all the virtqueues. */
771 vdev->config->reset(vdev);
772 vdev->config->del_vqs(vdev);
773 }
774
775 static int virtscsi_init(struct virtio_device *vdev,
776 struct virtio_scsi *vscsi)
777 {
778 int err;
779 u32 i;
780 u32 num_vqs;
781 vq_callback_t **callbacks;
782 const char **names;
783 struct virtqueue **vqs;
784 struct irq_affinity desc = { .pre_vectors = 2 };
785
786 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
787 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
788 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *),
789 GFP_KERNEL);
790 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL);
791
792 if (!callbacks || !vqs || !names) {
793 err = -ENOMEM;
794 goto out;
795 }
796
797 callbacks[0] = virtscsi_ctrl_done;
798 callbacks[1] = virtscsi_event_done;
799 names[0] = "control";
800 names[1] = "event";
801 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
802 callbacks[i] = virtscsi_req_done;
803 names[i] = "request";
804 }
805
806 /* Discover virtqueues and write information to configuration. */
807 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
808 if (err)
809 goto out;
810
811 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
812 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
813 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
814 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
815 vqs[i]);
816
817 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
818 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
819
820 err = 0;
821
822 out:
823 kfree(names);
824 kfree(callbacks);
825 kfree(vqs);
826 if (err)
827 virtscsi_remove_vqs(vdev);
828 return err;
829 }
830
831 static int virtscsi_probe(struct virtio_device *vdev)
832 {
833 struct Scsi_Host *shost;
834 struct virtio_scsi *vscsi;
835 int err;
836 u32 sg_elems, num_targets;
837 u32 cmd_per_lun;
838 u32 num_queues;
839
840 if (!vdev->config->get) {
841 dev_err(&vdev->dev, "%s failure: config access disabled\n",
842 __func__);
843 return -EINVAL;
844 }
845
846 /* We need to know how many queues before we allocate. */
847 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
848 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
849
850 num_targets = virtscsi_config_get(vdev, max_target) + 1;
851
852 shost = scsi_host_alloc(&virtscsi_host_template,
853 struct_size(vscsi, req_vqs, num_queues));
854 if (!shost)
855 return -ENOMEM;
856
857 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
858 shost->sg_tablesize = sg_elems;
859 vscsi = shost_priv(shost);
860 vscsi->vdev = vdev;
861 vscsi->num_queues = num_queues;
862 vdev->priv = shost;
863
864 err = virtscsi_init(vdev, vscsi);
865 if (err)
866 goto virtscsi_init_failed;
867
868 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
869
870 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
871 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
872 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
873
874 /* LUNs > 256 are reported with format 1, so they go in the range
875 * 16640-32767.
876 */
877 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
878 shost->max_id = num_targets;
879 shost->max_channel = 0;
880 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
881 shost->nr_hw_queues = num_queues;
882
883 #ifdef CONFIG_BLK_DEV_INTEGRITY
884 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
885 int host_prot;
886
887 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
888 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
889 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
890
891 scsi_host_set_prot(shost, host_prot);
892 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
893 }
894 #endif
895
896 err = scsi_add_host(shost, &vdev->dev);
897 if (err)
898 goto scsi_add_host_failed;
899
900 virtio_device_ready(vdev);
901
902 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
903 virtscsi_kick_event_all(vscsi);
904
905 scsi_scan_host(shost);
906 return 0;
907
908 scsi_add_host_failed:
909 vdev->config->del_vqs(vdev);
910 virtscsi_init_failed:
911 scsi_host_put(shost);
912 return err;
913 }
914
915 static void virtscsi_remove(struct virtio_device *vdev)
916 {
917 struct Scsi_Host *shost = virtio_scsi_host(vdev);
918 struct virtio_scsi *vscsi = shost_priv(shost);
919
920 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
921 virtscsi_cancel_event_work(vscsi);
922
923 scsi_remove_host(shost);
924 virtscsi_remove_vqs(vdev);
925 scsi_host_put(shost);
926 }
927
928 #ifdef CONFIG_PM_SLEEP
929 static int virtscsi_freeze(struct virtio_device *vdev)
930 {
931 virtscsi_remove_vqs(vdev);
932 return 0;
933 }
934
935 static int virtscsi_restore(struct virtio_device *vdev)
936 {
937 struct Scsi_Host *sh = virtio_scsi_host(vdev);
938 struct virtio_scsi *vscsi = shost_priv(sh);
939 int err;
940
941 err = virtscsi_init(vdev, vscsi);
942 if (err)
943 return err;
944
945 virtio_device_ready(vdev);
946
947 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
948 virtscsi_kick_event_all(vscsi);
949
950 return err;
951 }
952 #endif
953
954 static struct virtio_device_id id_table[] = {
955 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
956 { 0 },
957 };
958
959 static unsigned int features[] = {
960 VIRTIO_SCSI_F_HOTPLUG,
961 VIRTIO_SCSI_F_CHANGE,
962 #ifdef CONFIG_BLK_DEV_INTEGRITY
963 VIRTIO_SCSI_F_T10_PI,
964 #endif
965 };
966
967 static struct virtio_driver virtio_scsi_driver = {
968 .feature_table = features,
969 .feature_table_size = ARRAY_SIZE(features),
970 .driver.name = KBUILD_MODNAME,
971 .driver.owner = THIS_MODULE,
972 .id_table = id_table,
973 .probe = virtscsi_probe,
974 #ifdef CONFIG_PM_SLEEP
975 .freeze = virtscsi_freeze,
976 .restore = virtscsi_restore,
977 #endif
978 .remove = virtscsi_remove,
979 };
980
981 static int __init init(void)
982 {
983 int ret = -ENOMEM;
984
985 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
986 if (!virtscsi_cmd_cache) {
987 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
988 goto error;
989 }
990
991
992 virtscsi_cmd_pool =
993 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
994 virtscsi_cmd_cache);
995 if (!virtscsi_cmd_pool) {
996 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
997 goto error;
998 }
999 ret = register_virtio_driver(&virtio_scsi_driver);
1000 if (ret < 0)
1001 goto error;
1002
1003 return 0;
1004
1005 error:
1006 if (virtscsi_cmd_pool) {
1007 mempool_destroy(virtscsi_cmd_pool);
1008 virtscsi_cmd_pool = NULL;
1009 }
1010 if (virtscsi_cmd_cache) {
1011 kmem_cache_destroy(virtscsi_cmd_cache);
1012 virtscsi_cmd_cache = NULL;
1013 }
1014 return ret;
1015 }
1016
1017 static void __exit fini(void)
1018 {
1019 unregister_virtio_driver(&virtio_scsi_driver);
1020 mempool_destroy(virtscsi_cmd_pool);
1021 kmem_cache_destroy(virtscsi_cmd_cache);
1022 }
1023 module_init(init);
1024 module_exit(fini);
1025
1026 MODULE_DEVICE_TABLE(virtio, id_table);
1027 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1028 MODULE_LICENSE("GPL");
Linux with added FPC-III support