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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 */
40struct 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
57struct virtio_scsi_event_node {
58 struct virtio_scsi *vscsi;
59 struct virtio_scsi_event event;
60 struct work_struct work;
61};
62
63struct virtio_scsi_vq {
64 /* Protects vq */
65 spinlock_t vq_lock;
66
67 struct virtqueue *vq;
68};
69
70/* Driver instance state */
71struct 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
89static struct kmem_cache *virtscsi_cmd_cache;
90static mempool_t *virtscsi_cmd_pool;
91
92static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
93{
94 return vdev->priv;
95}
96
97static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
98{
99 if (resid)
100 scsi_set_resid(sc, min(resid, scsi_bufflen(sc)));
101}
102
103/*
104 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
105 *
106 * Called with vq_lock held.
107 */
108static 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 fallthrough;
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 (resp->sense_len) {
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 }
165
166 sc->scsi_done(sc);
167}
168
169static void virtscsi_vq_done(struct virtio_scsi *vscsi,
170 struct virtio_scsi_vq *virtscsi_vq,
171 void (*fn)(struct virtio_scsi *vscsi, void *buf))
172{
173 void *buf;
174 unsigned int len;
175 unsigned long flags;
176 struct virtqueue *vq = virtscsi_vq->vq;
177
178 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
179 do {
180 virtqueue_disable_cb(vq);
181 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
182 fn(vscsi, buf);
183
184 if (unlikely(virtqueue_is_broken(vq)))
185 break;
186 } while (!virtqueue_enable_cb(vq));
187 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
188}
189
190static void virtscsi_req_done(struct virtqueue *vq)
191{
192 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
193 struct virtio_scsi *vscsi = shost_priv(sh);
194 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
195 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
196
197 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
198};
199
200static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
201{
202 int i, num_vqs;
203
204 num_vqs = vscsi->num_queues;
205 for (i = 0; i < num_vqs; i++)
206 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
207 virtscsi_complete_cmd);
208}
209
210static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
211{
212 struct virtio_scsi_cmd *cmd = buf;
213
214 if (cmd->comp)
215 complete(cmd->comp);
216}
217
218static void virtscsi_ctrl_done(struct virtqueue *vq)
219{
220 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
221 struct virtio_scsi *vscsi = shost_priv(sh);
222
223 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
224};
225
226static void virtscsi_handle_event(struct work_struct *work);
227
228static int virtscsi_kick_event(struct virtio_scsi *vscsi,
229 struct virtio_scsi_event_node *event_node)
230{
231 int err;
232 struct scatterlist sg;
233 unsigned long flags;
234
235 INIT_WORK(&event_node->work, virtscsi_handle_event);
236 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
237
238 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
239
240 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
241 GFP_ATOMIC);
242 if (!err)
243 virtqueue_kick(vscsi->event_vq.vq);
244
245 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
246
247 return err;
248}
249
250static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
251{
252 int i;
253
254 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
255 vscsi->event_list[i].vscsi = vscsi;
256 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
257 }
258
259 return 0;
260}
261
262static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
263{
264 int i;
265
266 /* Stop scheduling work before calling cancel_work_sync. */
267 spin_lock_irq(&vscsi->event_vq.vq_lock);
268 vscsi->stop_events = true;
269 spin_unlock_irq(&vscsi->event_vq.vq_lock);
270
271 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
272 cancel_work_sync(&vscsi->event_list[i].work);
273}
274
275static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
276 struct virtio_scsi_event *event)
277{
278 struct scsi_device *sdev;
279 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
280 unsigned int target = event->lun[1];
281 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
282
283 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
284 case VIRTIO_SCSI_EVT_RESET_RESCAN:
285 if (lun == 0) {
286 scsi_scan_target(&shost->shost_gendev, 0, target,
287 SCAN_WILD_CARD, SCSI_SCAN_INITIAL);
288 } else {
289 scsi_add_device(shost, 0, target, lun);
290 }
291 break;
292 case VIRTIO_SCSI_EVT_RESET_REMOVED:
293 sdev = scsi_device_lookup(shost, 0, target, lun);
294 if (sdev) {
295 scsi_remove_device(sdev);
296 scsi_device_put(sdev);
297 } else {
298 pr_err("SCSI device %d 0 %d %d not found\n",
299 shost->host_no, target, lun);
300 }
301 break;
302 default:
303 pr_info("Unsupported virtio scsi event reason %x\n", event->reason);
304 }
305}
306
307static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
308 struct virtio_scsi_event *event)
309{
310 struct scsi_device *sdev;
311 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
312 unsigned int target = event->lun[1];
313 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
314 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255;
315 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8;
316
317 sdev = scsi_device_lookup(shost, 0, target, lun);
318 if (!sdev) {
319 pr_err("SCSI device %d 0 %d %d not found\n",
320 shost->host_no, target, lun);
321 return;
322 }
323
324 /* Handle "Parameters changed", "Mode parameters changed", and
325 "Capacity data has changed". */
326 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
327 scsi_rescan_device(&sdev->sdev_gendev);
328
329 scsi_device_put(sdev);
330}
331
332static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
333{
334 struct scsi_device *sdev;
335 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
336 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
337 int result, inquiry_len, inq_result_len = 256;
338 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
339
340 shost_for_each_device(sdev, shost) {
341 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
342
343 memset(scsi_cmd, 0, sizeof(scsi_cmd));
344 scsi_cmd[0] = INQUIRY;
345 scsi_cmd[4] = (unsigned char) inquiry_len;
346
347 memset(inq_result, 0, inq_result_len);
348
349 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
350 inq_result, inquiry_len, NULL,
351 SD_TIMEOUT, SD_MAX_RETRIES, NULL);
352
353 if (result == 0 && inq_result[0] >> 5) {
354 /* PQ indicates the LUN is not attached */
355 scsi_remove_device(sdev);
356 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) {
357 /*
358 * If all LUNs of a virtio-scsi device are unplugged
359 * it will respond with BAD TARGET on any INQUIRY
360 * command.
361 * Remove the device in this case as well.
362 */
363 scsi_remove_device(sdev);
364 }
365 }
366
367 kfree(inq_result);
368}
369
370static void virtscsi_handle_event(struct work_struct *work)
371{
372 struct virtio_scsi_event_node *event_node =
373 container_of(work, struct virtio_scsi_event_node, work);
374 struct virtio_scsi *vscsi = event_node->vscsi;
375 struct virtio_scsi_event *event = &event_node->event;
376
377 if (event->event &
378 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
379 event->event &= ~cpu_to_virtio32(vscsi->vdev,
380 VIRTIO_SCSI_T_EVENTS_MISSED);
381 virtscsi_rescan_hotunplug(vscsi);
382 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
383 }
384
385 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
386 case VIRTIO_SCSI_T_NO_EVENT:
387 break;
388 case VIRTIO_SCSI_T_TRANSPORT_RESET:
389 virtscsi_handle_transport_reset(vscsi, event);
390 break;
391 case VIRTIO_SCSI_T_PARAM_CHANGE:
392 virtscsi_handle_param_change(vscsi, event);
393 break;
394 default:
395 pr_err("Unsupported virtio scsi event %x\n", event->event);
396 }
397 virtscsi_kick_event(vscsi, event_node);
398}
399
400static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
401{
402 struct virtio_scsi_event_node *event_node = buf;
403
404 if (!vscsi->stop_events)
405 queue_work(system_freezable_wq, &event_node->work);
406}
407
408static void virtscsi_event_done(struct virtqueue *vq)
409{
410 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
411 struct virtio_scsi *vscsi = shost_priv(sh);
412
413 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
414};
415
416static int __virtscsi_add_cmd(struct virtqueue *vq,
417 struct virtio_scsi_cmd *cmd,
418 size_t req_size, size_t resp_size)
419{
420 struct scsi_cmnd *sc = cmd->sc;
421 struct scatterlist *sgs[6], req, resp;
422 struct sg_table *out, *in;
423 unsigned out_num = 0, in_num = 0;
424
425 out = in = NULL;
426
427 if (sc && sc->sc_data_direction != DMA_NONE) {
428 if (sc->sc_data_direction != DMA_FROM_DEVICE)
429 out = &sc->sdb.table;
430 if (sc->sc_data_direction != DMA_TO_DEVICE)
431 in = &sc->sdb.table;
432 }
433
434 /* Request header. */
435 sg_init_one(&req, &cmd->req, req_size);
436 sgs[out_num++] = &req;
437
438 /* Data-out buffer. */
439 if (out) {
440 /* Place WRITE protection SGLs before Data OUT payload */
441 if (scsi_prot_sg_count(sc))
442 sgs[out_num++] = scsi_prot_sglist(sc);
443 sgs[out_num++] = out->sgl;
444 }
445
446 /* Response header. */
447 sg_init_one(&resp, &cmd->resp, resp_size);
448 sgs[out_num + in_num++] = &resp;
449
450 /* Data-in buffer */
451 if (in) {
452 /* Place READ protection SGLs before Data IN payload */
453 if (scsi_prot_sg_count(sc))
454 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
455 sgs[out_num + in_num++] = in->sgl;
456 }
457
458 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
459}
460
461static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
462{
463 bool needs_kick;
464 unsigned long flags;
465
466 spin_lock_irqsave(&vq->vq_lock, flags);
467 needs_kick = virtqueue_kick_prepare(vq->vq);
468 spin_unlock_irqrestore(&vq->vq_lock, flags);
469
470 if (needs_kick)
471 virtqueue_notify(vq->vq);
472}
473
474/**
475 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
476 * @vq : the struct virtqueue we're talking about
477 * @cmd : command structure
478 * @req_size : size of the request buffer
479 * @resp_size : size of the response buffer
480 * @kick : whether to kick the virtqueue immediately
481 */
482static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
483 struct virtio_scsi_cmd *cmd,
484 size_t req_size, size_t resp_size,
485 bool kick)
486{
487 unsigned long flags;
488 int err;
489 bool needs_kick = false;
490
491 spin_lock_irqsave(&vq->vq_lock, flags);
492 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
493 if (!err && kick)
494 needs_kick = virtqueue_kick_prepare(vq->vq);
495
496 spin_unlock_irqrestore(&vq->vq_lock, flags);
497
498 if (needs_kick)
499 virtqueue_notify(vq->vq);
500 return err;
501}
502
503static void virtio_scsi_init_hdr(struct virtio_device *vdev,
504 struct virtio_scsi_cmd_req *cmd,
505 struct scsi_cmnd *sc)
506{
507 cmd->lun[0] = 1;
508 cmd->lun[1] = sc->device->id;
509 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
510 cmd->lun[3] = sc->device->lun & 0xff;
511 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
512 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
513 cmd->prio = 0;
514 cmd->crn = 0;
515}
516
517#ifdef CONFIG_BLK_DEV_INTEGRITY
518static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
519 struct virtio_scsi_cmd_req_pi *cmd_pi,
520 struct scsi_cmnd *sc)
521{
522 struct request *rq = sc->request;
523 struct blk_integrity *bi;
524
525 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
526
527 if (!rq || !scsi_prot_sg_count(sc))
528 return;
529
530 bi = blk_get_integrity(rq->rq_disk);
531
532 if (sc->sc_data_direction == DMA_TO_DEVICE)
533 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
534 bio_integrity_bytes(bi,
535 blk_rq_sectors(rq)));
536 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
537 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
538 bio_integrity_bytes(bi,
539 blk_rq_sectors(rq)));
540}
541#endif
542
543static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
544 struct scsi_cmnd *sc)
545{
546 u32 tag = blk_mq_unique_tag(sc->request);
547 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
548
549 return &vscsi->req_vqs[hwq];
550}
551
552static int virtscsi_queuecommand(struct Scsi_Host *shost,
553 struct scsi_cmnd *sc)
554{
555 struct virtio_scsi *vscsi = shost_priv(shost);
556 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
557 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
558 bool kick;
559 unsigned long flags;
560 int req_size;
561 int ret;
562
563 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
564
565 /* TODO: check feature bit and fail if unsupported? */
566 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
567
568 dev_dbg(&sc->device->sdev_gendev,
569 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
570
571 cmd->sc = sc;
572
573 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
574
575#ifdef CONFIG_BLK_DEV_INTEGRITY
576 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
577 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
578 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
579 req_size = sizeof(cmd->req.cmd_pi);
580 } else
581#endif
582 {
583 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
584 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
585 req_size = sizeof(cmd->req.cmd);
586 }
587
588 kick = (sc->flags & SCMD_LAST) != 0;
589 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick);
590 if (ret == -EIO) {
591 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
592 spin_lock_irqsave(&req_vq->vq_lock, flags);
593 virtscsi_complete_cmd(vscsi, cmd);
594 spin_unlock_irqrestore(&req_vq->vq_lock, flags);
595 } else if (ret != 0) {
596 return SCSI_MLQUEUE_HOST_BUSY;
597 }
598 return 0;
599}
600
601static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
602{
603 DECLARE_COMPLETION_ONSTACK(comp);
604 int ret = FAILED;
605
606 cmd->comp = ∁
607 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd,
608 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0)
609 goto out;
610
611 wait_for_completion(&comp);
612 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
613 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
614 ret = SUCCESS;
615
616 /*
617 * The spec guarantees that all requests related to the TMF have
618 * been completed, but the callback might not have run yet if
619 * we're using independent interrupts (e.g. MSI). Poll the
620 * virtqueues once.
621 *
622 * In the abort case, sc->scsi_done will do nothing, because
623 * the block layer must have detected a timeout and as a result
624 * REQ_ATOM_COMPLETE has been set.
625 */
626 virtscsi_poll_requests(vscsi);
627
628out:
629 mempool_free(cmd, virtscsi_cmd_pool);
630 return ret;
631}
632
633static int virtscsi_device_reset(struct scsi_cmnd *sc)
634{
635 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
636 struct virtio_scsi_cmd *cmd;
637
638 sdev_printk(KERN_INFO, sc->device, "device reset\n");
639 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
640 if (!cmd)
641 return FAILED;
642
643 memset(cmd, 0, sizeof(*cmd));
644 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
645 .type = VIRTIO_SCSI_T_TMF,
646 .subtype = cpu_to_virtio32(vscsi->vdev,
647 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
648 .lun[0] = 1,
649 .lun[1] = sc->device->id,
650 .lun[2] = (sc->device->lun >> 8) | 0x40,
651 .lun[3] = sc->device->lun & 0xff,
652 };
653 return virtscsi_tmf(vscsi, cmd);
654}
655
656static int virtscsi_device_alloc(struct scsi_device *sdevice)
657{
658 /*
659 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
660 * may have transfer limits which come from the host SCSI
661 * controller or something on the host side other than the
662 * target itself.
663 *
664 * To make this work properly, the hypervisor can adjust the
665 * target's VPD information to advertise these limits. But
666 * for that to work, the guest has to look at the VPD pages,
667 * which we won't do by default if it is an SPC-2 device, even
668 * if it does actually support it.
669 *
670 * So, set the blist to always try to read the VPD pages.
671 */
672 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
673
674 return 0;
675}
676
677
678/**
679 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
680 * @sdev: Virtscsi target whose queue depth to change
681 * @qdepth: New queue depth
682 */
683static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
684{
685 struct Scsi_Host *shost = sdev->host;
686 int max_depth = shost->cmd_per_lun;
687
688 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
689}
690
691static int virtscsi_abort(struct scsi_cmnd *sc)
692{
693 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
694 struct virtio_scsi_cmd *cmd;
695
696 scmd_printk(KERN_INFO, sc, "abort\n");
697 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
698 if (!cmd)
699 return FAILED;
700
701 memset(cmd, 0, sizeof(*cmd));
702 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
703 .type = VIRTIO_SCSI_T_TMF,
704 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
705 .lun[0] = 1,
706 .lun[1] = sc->device->id,
707 .lun[2] = (sc->device->lun >> 8) | 0x40,
708 .lun[3] = sc->device->lun & 0xff,
709 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
710 };
711 return virtscsi_tmf(vscsi, cmd);
712}
713
714static int virtscsi_map_queues(struct Scsi_Host *shost)
715{
716 struct virtio_scsi *vscsi = shost_priv(shost);
717 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
718
719 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2);
720}
721
722static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
723{
724 struct virtio_scsi *vscsi = shost_priv(shost);
725
726 virtscsi_kick_vq(&vscsi->req_vqs[hwq]);
727}
728
729/*
730 * The host guarantees to respond to each command, although I/O
731 * latencies might be higher than on bare metal. Reset the timer
732 * unconditionally to give the host a chance to perform EH.
733 */
734static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
735{
736 return BLK_EH_RESET_TIMER;
737}
738
739static struct scsi_host_template virtscsi_host_template = {
740 .module = THIS_MODULE,
741 .name = "Virtio SCSI HBA",
742 .proc_name = "virtio_scsi",
743 .this_id = -1,
744 .cmd_size = sizeof(struct virtio_scsi_cmd),
745 .queuecommand = virtscsi_queuecommand,
746 .commit_rqs = virtscsi_commit_rqs,
747 .change_queue_depth = virtscsi_change_queue_depth,
748 .eh_abort_handler = virtscsi_abort,
749 .eh_device_reset_handler = virtscsi_device_reset,
750 .eh_timed_out = virtscsi_eh_timed_out,
751 .slave_alloc = virtscsi_device_alloc,
752
753 .dma_boundary = UINT_MAX,
754 .map_queues = virtscsi_map_queues,
755 .track_queue_depth = 1,
756};
757
758#define virtscsi_config_get(vdev, fld) \
759 ({ \
760 __virtio_native_type(struct virtio_scsi_config, fld) __val; \
761 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
762 __val; \
763 })
764
765#define virtscsi_config_set(vdev, fld, val) \
766 do { \
767 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \
768 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
769 } while(0)
770
771static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
772 struct virtqueue *vq)
773{
774 spin_lock_init(&virtscsi_vq->vq_lock);
775 virtscsi_vq->vq = vq;
776}
777
778static void virtscsi_remove_vqs(struct virtio_device *vdev)
779{
780 /* Stop all the virtqueues. */
781 vdev->config->reset(vdev);
782 vdev->config->del_vqs(vdev);
783}
784
785static int virtscsi_init(struct virtio_device *vdev,
786 struct virtio_scsi *vscsi)
787{
788 int err;
789 u32 i;
790 u32 num_vqs;
791 vq_callback_t **callbacks;
792 const char **names;
793 struct virtqueue **vqs;
794 struct irq_affinity desc = { .pre_vectors = 2 };
795
796 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
797 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
798 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *),
799 GFP_KERNEL);
800 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL);
801
802 if (!callbacks || !vqs || !names) {
803 err = -ENOMEM;
804 goto out;
805 }
806
807 callbacks[0] = virtscsi_ctrl_done;
808 callbacks[1] = virtscsi_event_done;
809 names[0] = "control";
810 names[1] = "event";
811 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
812 callbacks[i] = virtscsi_req_done;
813 names[i] = "request";
814 }
815
816 /* Discover virtqueues and write information to configuration. */
817 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
818 if (err)
819 goto out;
820
821 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
822 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
823 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
824 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
825 vqs[i]);
826
827 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
828 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
829
830 err = 0;
831
832out:
833 kfree(names);
834 kfree(callbacks);
835 kfree(vqs);
836 if (err)
837 virtscsi_remove_vqs(vdev);
838 return err;
839}
840
841static int virtscsi_probe(struct virtio_device *vdev)
842{
843 struct Scsi_Host *shost;
844 struct virtio_scsi *vscsi;
845 int err;
846 u32 sg_elems, num_targets;
847 u32 cmd_per_lun;
848 u32 num_queues;
849
850 if (!vdev->config->get) {
851 dev_err(&vdev->dev, "%s failure: config access disabled\n",
852 __func__);
853 return -EINVAL;
854 }
855
856 /* We need to know how many queues before we allocate. */
857 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
858 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
859
860 num_targets = virtscsi_config_get(vdev, max_target) + 1;
861
862 shost = scsi_host_alloc(&virtscsi_host_template,
863 struct_size(vscsi, req_vqs, num_queues));
864 if (!shost)
865 return -ENOMEM;
866
867 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
868 shost->sg_tablesize = sg_elems;
869 vscsi = shost_priv(shost);
870 vscsi->vdev = vdev;
871 vscsi->num_queues = num_queues;
872 vdev->priv = shost;
873
874 err = virtscsi_init(vdev, vscsi);
875 if (err)
876 goto virtscsi_init_failed;
877
878 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
879
880 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
881 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
882 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
883
884 /* LUNs > 256 are reported with format 1, so they go in the range
885 * 16640-32767.
886 */
887 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
888 shost->max_id = num_targets;
889 shost->max_channel = 0;
890 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
891 shost->nr_hw_queues = num_queues;
892
893#ifdef CONFIG_BLK_DEV_INTEGRITY
894 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
895 int host_prot;
896
897 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
898 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
899 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
900
901 scsi_host_set_prot(shost, host_prot);
902 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
903 }
904#endif
905
906 err = scsi_add_host(shost, &vdev->dev);
907 if (err)
908 goto scsi_add_host_failed;
909
910 virtio_device_ready(vdev);
911
912 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
913 virtscsi_kick_event_all(vscsi);
914
915 scsi_scan_host(shost);
916 return 0;
917
918scsi_add_host_failed:
919 vdev->config->del_vqs(vdev);
920virtscsi_init_failed:
921 scsi_host_put(shost);
922 return err;
923}
924
925static void virtscsi_remove(struct virtio_device *vdev)
926{
927 struct Scsi_Host *shost = virtio_scsi_host(vdev);
928 struct virtio_scsi *vscsi = shost_priv(shost);
929
930 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
931 virtscsi_cancel_event_work(vscsi);
932
933 scsi_remove_host(shost);
934 virtscsi_remove_vqs(vdev);
935 scsi_host_put(shost);
936}
937
938#ifdef CONFIG_PM_SLEEP
939static int virtscsi_freeze(struct virtio_device *vdev)
940{
941 virtscsi_remove_vqs(vdev);
942 return 0;
943}
944
945static int virtscsi_restore(struct virtio_device *vdev)
946{
947 struct Scsi_Host *sh = virtio_scsi_host(vdev);
948 struct virtio_scsi *vscsi = shost_priv(sh);
949 int err;
950
951 err = virtscsi_init(vdev, vscsi);
952 if (err)
953 return err;
954
955 virtio_device_ready(vdev);
956
957 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
958 virtscsi_kick_event_all(vscsi);
959
960 return err;
961}
962#endif
963
964static struct virtio_device_id id_table[] = {
965 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
966 { 0 },
967};
968
969static unsigned int features[] = {
970 VIRTIO_SCSI_F_HOTPLUG,
971 VIRTIO_SCSI_F_CHANGE,
972#ifdef CONFIG_BLK_DEV_INTEGRITY
973 VIRTIO_SCSI_F_T10_PI,
974#endif
975};
976
977static struct virtio_driver virtio_scsi_driver = {
978 .feature_table = features,
979 .feature_table_size = ARRAY_SIZE(features),
980 .driver.name = KBUILD_MODNAME,
981 .driver.owner = THIS_MODULE,
982 .id_table = id_table,
983 .probe = virtscsi_probe,
984#ifdef CONFIG_PM_SLEEP
985 .freeze = virtscsi_freeze,
986 .restore = virtscsi_restore,
987#endif
988 .remove = virtscsi_remove,
989};
990
991static int __init init(void)
992{
993 int ret = -ENOMEM;
994
995 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
996 if (!virtscsi_cmd_cache) {
997 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
998 goto error;
999 }
1000
1001
1002 virtscsi_cmd_pool =
1003 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1004 virtscsi_cmd_cache);
1005 if (!virtscsi_cmd_pool) {
1006 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1007 goto error;
1008 }
1009 ret = register_virtio_driver(&virtio_scsi_driver);
1010 if (ret < 0)
1011 goto error;
1012
1013 return 0;
1014
1015error:
1016 mempool_destroy(virtscsi_cmd_pool);
1017 virtscsi_cmd_pool = NULL;
1018 kmem_cache_destroy(virtscsi_cmd_cache);
1019 virtscsi_cmd_cache = NULL;
1020 return ret;
1021}
1022
1023static void __exit fini(void)
1024{
1025 unregister_virtio_driver(&virtio_scsi_driver);
1026 mempool_destroy(virtscsi_cmd_pool);
1027 kmem_cache_destroy(virtscsi_cmd_cache);
1028}
1029module_init(init);
1030module_exit(fini);
1031
1032MODULE_DEVICE_TABLE(virtio, id_table);
1033MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1034MODULE_LICENSE("GPL");
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
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);
178 else
179 mempool_free(cmd, virtscsi_cmd_pool);
180}
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[idx++] = *sg_elem;
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);
315 int ret = FAILED;
316
317 cmd->comp = ∁
318 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;
322
323 wait_for_completion(&comp);
324 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
325 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
326 ret = SUCCESS;
327
328out:
329 mempool_free(cmd, virtscsi_cmd_pool);
330 return ret;
331}
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");