1 // SPDX-License-Identifier: GPL-2.0-only
2 //#define DEBUG
3 #include <linux/spinlock.h>
4 #include <linux/slab.h>
5 #include <linux/blkdev.h>
6 #include <linux/hdreg.h>
7 #include <linux/module.h>
8 #include <linux/mutex.h>
9 #include <linux/interrupt.h>
10 #include <linux/virtio.h>
11 #include <linux/virtio_blk.h>
12 #include <linux/scatterlist.h>
13 #include <linux/string_helpers.h>
14 #include <linux/idr.h>
15 #include <linux/blk-mq.h>
16 #include <linux/blk-mq-virtio.h>
17 #include <linux/numa.h>
18 #include <uapi/linux/virtio_ring.h>
19
20 #define PART_BITS 4
21 #define VQ_NAME_LEN 16
22 #define MAX_DISCARD_SEGMENTS 256u
23
24 /* The maximum number of sg elements that fit into a virtqueue */
25 #define VIRTIO_BLK_MAX_SG_ELEMS 32768
26
27 #ifdef CONFIG_ARCH_NO_SG_CHAIN
28 #define VIRTIO_BLK_INLINE_SG_CNT 0
29 #else
30 #define VIRTIO_BLK_INLINE_SG_CNT 2
31 #endif
32
33 static unsigned int num_request_queues;
34 module_param(num_request_queues, uint, 0644);
35 MODULE_PARM_DESC(num_request_queues,
36 "Limit the number of request queues to use for blk device. "
37 "0 for no limit. "
38 "Values > nr_cpu_ids truncated to nr_cpu_ids.");
39
40 static unsigned int poll_queues;
41 module_param(poll_queues, uint, 0644);
42 MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O");
43
44 static int major;
45 static DEFINE_IDA(vd_index_ida);
46
47 static struct workqueue_struct *virtblk_wq;
48
49 struct virtio_blk_vq {
50 struct virtqueue *vq;
51 spinlock_t lock;
52 char name[VQ_NAME_LEN];
53 } ____cacheline_aligned_in_smp;
54
55 struct virtio_blk {
56 /*
57 * This mutex must be held by anything that may run after
58 * virtblk_remove() sets vblk->vdev to NULL.
59 *
60 * blk-mq, virtqueue processing, and sysfs attribute code paths are
61 * shut down before vblk->vdev is set to NULL and therefore do not need
62 * to hold this mutex.
63 */
64 struct mutex vdev_mutex;
65 struct virtio_device *vdev;
66
67 /* The disk structure for the kernel. */
68 struct gendisk *disk;
69
70 /* Block layer tags. */
71 struct blk_mq_tag_set tag_set;
72
73 /* Process context for config space updates */
74 struct work_struct config_work;
75
76 /* Ida index - used to track minor number allocations. */
77 int index;
78
79 /* num of vqs */
80 int num_vqs;
81 int io_queues[HCTX_MAX_TYPES];
82 struct virtio_blk_vq *vqs;
83 };
84
85 struct virtblk_req {
86 struct virtio_blk_outhdr out_hdr;
87 u8 status;
88 struct sg_table sg_table;
89 struct scatterlist sg[];
90 };
91
virtblk_result(struct virtblk_req * vbr)92 static inline blk_status_t virtblk_result(struct virtblk_req *vbr)
93 {
94 switch (vbr->status) {
95 case VIRTIO_BLK_S_OK:
96 return BLK_STS_OK;
97 case VIRTIO_BLK_S_UNSUPP:
98 return BLK_STS_NOTSUPP;
99 default:
100 return BLK_STS_IOERR;
101 }
102 }
103
get_virtio_blk_vq(struct blk_mq_hw_ctx * hctx)104 static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx)
105 {
106 struct virtio_blk *vblk = hctx->queue->queuedata;
107 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
108
109 return vq;
110 }
111
virtblk_add_req(struct virtqueue * vq,struct virtblk_req * vbr)112 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr)
113 {
114 struct scatterlist hdr, status, *sgs[3];
115 unsigned int num_out = 0, num_in = 0;
116
117 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
118 sgs[num_out++] = &hdr;
119
120 if (vbr->sg_table.nents) {
121 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
122 sgs[num_out++] = vbr->sg_table.sgl;
123 else
124 sgs[num_out + num_in++] = vbr->sg_table.sgl;
125 }
126
127 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
128 sgs[num_out + num_in++] = &status;
129
130 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
131 }
132
virtblk_setup_discard_write_zeroes_erase(struct request * req,bool unmap)133 static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap)
134 {
135 unsigned short segments = blk_rq_nr_discard_segments(req);
136 unsigned short n = 0;
137 struct virtio_blk_discard_write_zeroes *range;
138 struct bio *bio;
139 u32 flags = 0;
140
141 if (unmap)
142 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
143
144 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
145 if (!range)
146 return -ENOMEM;
147
148 /*
149 * Single max discard segment means multi-range discard isn't
150 * supported, and block layer only runs contiguity merge like
151 * normal RW request. So we can't reply on bio for retrieving
152 * each range info.
153 */
154 if (queue_max_discard_segments(req->q) == 1) {
155 range[0].flags = cpu_to_le32(flags);
156 range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req));
157 range[0].sector = cpu_to_le64(blk_rq_pos(req));
158 n = 1;
159 } else {
160 __rq_for_each_bio(bio, req) {
161 u64 sector = bio->bi_iter.bi_sector;
162 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
163
164 range[n].flags = cpu_to_le32(flags);
165 range[n].num_sectors = cpu_to_le32(num_sectors);
166 range[n].sector = cpu_to_le64(sector);
167 n++;
168 }
169 }
170
171 WARN_ON_ONCE(n != segments);
172
173 req->special_vec.bv_page = virt_to_page(range);
174 req->special_vec.bv_offset = offset_in_page(range);
175 req->special_vec.bv_len = sizeof(*range) * segments;
176 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
177
178 return 0;
179 }
180
virtblk_unmap_data(struct request * req,struct virtblk_req * vbr)181 static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr)
182 {
183 if (blk_rq_nr_phys_segments(req))
184 sg_free_table_chained(&vbr->sg_table,
185 VIRTIO_BLK_INLINE_SG_CNT);
186 }
187
virtblk_map_data(struct blk_mq_hw_ctx * hctx,struct request * req,struct virtblk_req * vbr)188 static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req,
189 struct virtblk_req *vbr)
190 {
191 int err;
192
193 if (!blk_rq_nr_phys_segments(req))
194 return 0;
195
196 vbr->sg_table.sgl = vbr->sg;
197 err = sg_alloc_table_chained(&vbr->sg_table,
198 blk_rq_nr_phys_segments(req),
199 vbr->sg_table.sgl,
200 VIRTIO_BLK_INLINE_SG_CNT);
201 if (unlikely(err))
202 return -ENOMEM;
203
204 return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl);
205 }
206
virtblk_cleanup_cmd(struct request * req)207 static void virtblk_cleanup_cmd(struct request *req)
208 {
209 if (req->rq_flags & RQF_SPECIAL_PAYLOAD)
210 kfree(bvec_virt(&req->special_vec));
211 }
212
virtblk_setup_cmd(struct virtio_device * vdev,struct request * req,struct virtblk_req * vbr)213 static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
214 struct request *req,
215 struct virtblk_req *vbr)
216 {
217 bool unmap = false;
218 u32 type;
219
220 vbr->out_hdr.sector = 0;
221
222 switch (req_op(req)) {
223 case REQ_OP_READ:
224 type = VIRTIO_BLK_T_IN;
225 vbr->out_hdr.sector = cpu_to_virtio64(vdev,
226 blk_rq_pos(req));
227 break;
228 case REQ_OP_WRITE:
229 type = VIRTIO_BLK_T_OUT;
230 vbr->out_hdr.sector = cpu_to_virtio64(vdev,
231 blk_rq_pos(req));
232 break;
233 case REQ_OP_FLUSH:
234 type = VIRTIO_BLK_T_FLUSH;
235 break;
236 case REQ_OP_DISCARD:
237 type = VIRTIO_BLK_T_DISCARD;
238 break;
239 case REQ_OP_WRITE_ZEROES:
240 type = VIRTIO_BLK_T_WRITE_ZEROES;
241 unmap = !(req->cmd_flags & REQ_NOUNMAP);
242 break;
243 case REQ_OP_SECURE_ERASE:
244 type = VIRTIO_BLK_T_SECURE_ERASE;
245 break;
246 case REQ_OP_DRV_IN:
247 type = VIRTIO_BLK_T_GET_ID;
248 break;
249 default:
250 WARN_ON_ONCE(1);
251 return BLK_STS_IOERR;
252 }
253
254 vbr->out_hdr.type = cpu_to_virtio32(vdev, type);
255 vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));
256
257 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES ||
258 type == VIRTIO_BLK_T_SECURE_ERASE) {
259 if (virtblk_setup_discard_write_zeroes_erase(req, unmap))
260 return BLK_STS_RESOURCE;
261 }
262
263 return 0;
264 }
265
virtblk_request_done(struct request * req)266 static inline void virtblk_request_done(struct request *req)
267 {
268 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
269
270 virtblk_unmap_data(req, vbr);
271 virtblk_cleanup_cmd(req);
272 blk_mq_end_request(req, virtblk_result(vbr));
273 }
274
virtblk_done(struct virtqueue * vq)275 static void virtblk_done(struct virtqueue *vq)
276 {
277 struct virtio_blk *vblk = vq->vdev->priv;
278 bool req_done = false;
279 int qid = vq->index;
280 struct virtblk_req *vbr;
281 unsigned long flags;
282 unsigned int len;
283
284 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
285 do {
286 virtqueue_disable_cb(vq);
287 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
288 struct request *req = blk_mq_rq_from_pdu(vbr);
289
290 if (likely(!blk_should_fake_timeout(req->q)))
291 blk_mq_complete_request(req);
292 req_done = true;
293 }
294 if (unlikely(virtqueue_is_broken(vq)))
295 break;
296 } while (!virtqueue_enable_cb(vq));
297
298 /* In case queue is stopped waiting for more buffers. */
299 if (req_done)
300 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
301 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
302 }
303
virtio_commit_rqs(struct blk_mq_hw_ctx * hctx)304 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
305 {
306 struct virtio_blk *vblk = hctx->queue->queuedata;
307 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
308 bool kick;
309
310 spin_lock_irq(&vq->lock);
311 kick = virtqueue_kick_prepare(vq->vq);
312 spin_unlock_irq(&vq->lock);
313
314 if (kick)
315 virtqueue_notify(vq->vq);
316 }
317
virtblk_prep_rq(struct blk_mq_hw_ctx * hctx,struct virtio_blk * vblk,struct request * req,struct virtblk_req * vbr)318 static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx,
319 struct virtio_blk *vblk,
320 struct request *req,
321 struct virtblk_req *vbr)
322 {
323 blk_status_t status;
324
325 status = virtblk_setup_cmd(vblk->vdev, req, vbr);
326 if (unlikely(status))
327 return status;
328
329 vbr->sg_table.nents = virtblk_map_data(hctx, req, vbr);
330 if (unlikely(vbr->sg_table.nents < 0)) {
331 virtblk_cleanup_cmd(req);
332 return BLK_STS_RESOURCE;
333 }
334
335 blk_mq_start_request(req);
336
337 return BLK_STS_OK;
338 }
339
virtio_queue_rq(struct blk_mq_hw_ctx * hctx,const struct blk_mq_queue_data * bd)340 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
341 const struct blk_mq_queue_data *bd)
342 {
343 struct virtio_blk *vblk = hctx->queue->queuedata;
344 struct request *req = bd->rq;
345 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
346 unsigned long flags;
347 int qid = hctx->queue_num;
348 bool notify = false;
349 blk_status_t status;
350 int err;
351
352 status = virtblk_prep_rq(hctx, vblk, req, vbr);
353 if (unlikely(status))
354 return status;
355
356 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
357 err = virtblk_add_req(vblk->vqs[qid].vq, vbr);
358 if (err) {
359 virtqueue_kick(vblk->vqs[qid].vq);
360 /* Don't stop the queue if -ENOMEM: we may have failed to
361 * bounce the buffer due to global resource outage.
362 */
363 if (err == -ENOSPC)
364 blk_mq_stop_hw_queue(hctx);
365 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
366 virtblk_unmap_data(req, vbr);
367 virtblk_cleanup_cmd(req);
368 switch (err) {
369 case -ENOSPC:
370 return BLK_STS_DEV_RESOURCE;
371 case -ENOMEM:
372 return BLK_STS_RESOURCE;
373 default:
374 return BLK_STS_IOERR;
375 }
376 }
377
378 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
379 notify = true;
380 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
381
382 if (notify)
383 virtqueue_notify(vblk->vqs[qid].vq);
384 return BLK_STS_OK;
385 }
386
virtblk_prep_rq_batch(struct request * req)387 static bool virtblk_prep_rq_batch(struct request *req)
388 {
389 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
390 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
391
392 req->mq_hctx->tags->rqs[req->tag] = req;
393
394 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK;
395 }
396
virtblk_add_req_batch(struct virtio_blk_vq * vq,struct request ** rqlist)397 static bool virtblk_add_req_batch(struct virtio_blk_vq *vq,
398 struct request **rqlist)
399 {
400 unsigned long flags;
401 int err;
402 bool kick;
403
404 spin_lock_irqsave(&vq->lock, flags);
405
406 while (!rq_list_empty(*rqlist)) {
407 struct request *req = rq_list_pop(rqlist);
408 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
409
410 err = virtblk_add_req(vq->vq, vbr);
411 if (err) {
412 virtblk_unmap_data(req, vbr);
413 virtblk_cleanup_cmd(req);
414 blk_mq_requeue_request(req, true);
415 }
416 }
417
418 kick = virtqueue_kick_prepare(vq->vq);
419 spin_unlock_irqrestore(&vq->lock, flags);
420
421 return kick;
422 }
423
virtio_queue_rqs(struct request ** rqlist)424 static void virtio_queue_rqs(struct request **rqlist)
425 {
426 struct request *req, *next, *prev = NULL;
427 struct request *requeue_list = NULL;
428
429 rq_list_for_each_safe(rqlist, req, next) {
430 struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx);
431 bool kick;
432
433 if (!virtblk_prep_rq_batch(req)) {
434 rq_list_move(rqlist, &requeue_list, req, prev);
435 req = prev;
436 if (!req)
437 continue;
438 }
439
440 if (!next || req->mq_hctx != next->mq_hctx) {
441 req->rq_next = NULL;
442 kick = virtblk_add_req_batch(vq, rqlist);
443 if (kick)
444 virtqueue_notify(vq->vq);
445
446 *rqlist = next;
447 prev = NULL;
448 } else
449 prev = req;
450 }
451
452 *rqlist = requeue_list;
453 }
454
455 /* return id (s/n) string for *disk to *id_str
456 */
virtblk_get_id(struct gendisk * disk,char * id_str)457 static int virtblk_get_id(struct gendisk *disk, char *id_str)
458 {
459 struct virtio_blk *vblk = disk->private_data;
460 struct request_queue *q = vblk->disk->queue;
461 struct request *req;
462 int err;
463
464 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
465 if (IS_ERR(req))
466 return PTR_ERR(req);
467
468 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
469 if (err)
470 goto out;
471
472 blk_execute_rq(req, false);
473 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
474 out:
475 blk_mq_free_request(req);
476 return err;
477 }
478
479 /* We provide getgeo only to please some old bootloader/partitioning tools */
virtblk_getgeo(struct block_device * bd,struct hd_geometry * geo)480 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
481 {
482 struct virtio_blk *vblk = bd->bd_disk->private_data;
483 int ret = 0;
484
485 mutex_lock(&vblk->vdev_mutex);
486
487 if (!vblk->vdev) {
488 ret = -ENXIO;
489 goto out;
490 }
491
492 /* see if the host passed in geometry config */
493 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
494 virtio_cread(vblk->vdev, struct virtio_blk_config,
495 geometry.cylinders, &geo->cylinders);
496 virtio_cread(vblk->vdev, struct virtio_blk_config,
497 geometry.heads, &geo->heads);
498 virtio_cread(vblk->vdev, struct virtio_blk_config,
499 geometry.sectors, &geo->sectors);
500 } else {
501 /* some standard values, similar to sd */
502 geo->heads = 1 << 6;
503 geo->sectors = 1 << 5;
504 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
505 }
506 out:
507 mutex_unlock(&vblk->vdev_mutex);
508 return ret;
509 }
510
virtblk_free_disk(struct gendisk * disk)511 static void virtblk_free_disk(struct gendisk *disk)
512 {
513 struct virtio_blk *vblk = disk->private_data;
514
515 ida_simple_remove(&vd_index_ida, vblk->index);
516 mutex_destroy(&vblk->vdev_mutex);
517 kfree(vblk);
518 }
519
520 static const struct block_device_operations virtblk_fops = {
521 .owner = THIS_MODULE,
522 .getgeo = virtblk_getgeo,
523 .free_disk = virtblk_free_disk,
524 };
525
index_to_minor(int index)526 static int index_to_minor(int index)
527 {
528 return index << PART_BITS;
529 }
530
minor_to_index(int minor)531 static int minor_to_index(int minor)
532 {
533 return minor >> PART_BITS;
534 }
535
serial_show(struct device * dev,struct device_attribute * attr,char * buf)536 static ssize_t serial_show(struct device *dev,
537 struct device_attribute *attr, char *buf)
538 {
539 struct gendisk *disk = dev_to_disk(dev);
540 int err;
541
542 /* sysfs gives us a PAGE_SIZE buffer */
543 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
544
545 buf[VIRTIO_BLK_ID_BYTES] = '\0';
546 err = virtblk_get_id(disk, buf);
547 if (!err)
548 return strlen(buf);
549
550 if (err == -EIO) /* Unsupported? Make it empty. */
551 return 0;
552
553 return err;
554 }
555
556 static DEVICE_ATTR_RO(serial);
557
558 /* The queue's logical block size must be set before calling this */
virtblk_update_capacity(struct virtio_blk * vblk,bool resize)559 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
560 {
561 struct virtio_device *vdev = vblk->vdev;
562 struct request_queue *q = vblk->disk->queue;
563 char cap_str_2[10], cap_str_10[10];
564 unsigned long long nblocks;
565 u64 capacity;
566
567 /* Host must always specify the capacity. */
568 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
569
570 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
571
572 string_get_size(nblocks, queue_logical_block_size(q),
573 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
574 string_get_size(nblocks, queue_logical_block_size(q),
575 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
576
577 dev_notice(&vdev->dev,
578 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
579 vblk->disk->disk_name,
580 resize ? "new size: " : "",
581 nblocks,
582 queue_logical_block_size(q),
583 cap_str_10,
584 cap_str_2);
585
586 set_capacity_and_notify(vblk->disk, capacity);
587 }
588
virtblk_config_changed_work(struct work_struct * work)589 static void virtblk_config_changed_work(struct work_struct *work)
590 {
591 struct virtio_blk *vblk =
592 container_of(work, struct virtio_blk, config_work);
593
594 virtblk_update_capacity(vblk, true);
595 }
596
virtblk_config_changed(struct virtio_device * vdev)597 static void virtblk_config_changed(struct virtio_device *vdev)
598 {
599 struct virtio_blk *vblk = vdev->priv;
600
601 queue_work(virtblk_wq, &vblk->config_work);
602 }
603
init_vq(struct virtio_blk * vblk)604 static int init_vq(struct virtio_blk *vblk)
605 {
606 int err;
607 int i;
608 vq_callback_t **callbacks;
609 const char **names;
610 struct virtqueue **vqs;
611 unsigned short num_vqs;
612 unsigned int num_poll_vqs;
613 struct virtio_device *vdev = vblk->vdev;
614 struct irq_affinity desc = { 0, };
615
616 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
617 struct virtio_blk_config, num_queues,
618 &num_vqs);
619 if (err)
620 num_vqs = 1;
621
622 if (!err && !num_vqs) {
623 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n");
624 return -EINVAL;
625 }
626
627 num_vqs = min_t(unsigned int,
628 min_not_zero(num_request_queues, nr_cpu_ids),
629 num_vqs);
630
631 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1);
632
633 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs;
634 vblk->io_queues[HCTX_TYPE_READ] = 0;
635 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
636
637 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
638 vblk->io_queues[HCTX_TYPE_DEFAULT],
639 vblk->io_queues[HCTX_TYPE_READ],
640 vblk->io_queues[HCTX_TYPE_POLL]);
641
642 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
643 if (!vblk->vqs)
644 return -ENOMEM;
645
646 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
647 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
648 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
649 if (!names || !callbacks || !vqs) {
650 err = -ENOMEM;
651 goto out;
652 }
653
654 for (i = 0; i < num_vqs - num_poll_vqs; i++) {
655 callbacks[i] = virtblk_done;
656 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
657 names[i] = vblk->vqs[i].name;
658 }
659
660 for (; i < num_vqs; i++) {
661 callbacks[i] = NULL;
662 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
663 names[i] = vblk->vqs[i].name;
664 }
665
666 /* Discover virtqueues and write information to configuration. */
667 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
668 if (err)
669 goto out;
670
671 for (i = 0; i < num_vqs; i++) {
672 spin_lock_init(&vblk->vqs[i].lock);
673 vblk->vqs[i].vq = vqs[i];
674 }
675 vblk->num_vqs = num_vqs;
676
677 out:
678 kfree(vqs);
679 kfree(callbacks);
680 kfree(names);
681 if (err)
682 kfree(vblk->vqs);
683 return err;
684 }
685
686 /*
687 * Legacy naming scheme used for virtio devices. We are stuck with it for
688 * virtio blk but don't ever use it for any new driver.
689 */
virtblk_name_format(char * prefix,int index,char * buf,int buflen)690 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
691 {
692 const int base = 'z' - 'a' + 1;
693 char *begin = buf + strlen(prefix);
694 char *end = buf + buflen;
695 char *p;
696 int unit;
697
698 p = end - 1;
699 *p = '\0';
700 unit = base;
701 do {
702 if (p == begin)
703 return -EINVAL;
704 *--p = 'a' + (index % unit);
705 index = (index / unit) - 1;
706 } while (index >= 0);
707
708 memmove(begin, p, end - p);
709 memcpy(buf, prefix, strlen(prefix));
710
711 return 0;
712 }
713
virtblk_get_cache_mode(struct virtio_device * vdev)714 static int virtblk_get_cache_mode(struct virtio_device *vdev)
715 {
716 u8 writeback;
717 int err;
718
719 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
720 struct virtio_blk_config, wce,
721 &writeback);
722
723 /*
724 * If WCE is not configurable and flush is not available,
725 * assume no writeback cache is in use.
726 */
727 if (err)
728 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
729
730 return writeback;
731 }
732
virtblk_update_cache_mode(struct virtio_device * vdev)733 static void virtblk_update_cache_mode(struct virtio_device *vdev)
734 {
735 u8 writeback = virtblk_get_cache_mode(vdev);
736 struct virtio_blk *vblk = vdev->priv;
737
738 blk_queue_write_cache(vblk->disk->queue, writeback, false);
739 }
740
741 static const char *const virtblk_cache_types[] = {
742 "write through", "write back"
743 };
744
745 static ssize_t
cache_type_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)746 cache_type_store(struct device *dev, struct device_attribute *attr,
747 const char *buf, size_t count)
748 {
749 struct gendisk *disk = dev_to_disk(dev);
750 struct virtio_blk *vblk = disk->private_data;
751 struct virtio_device *vdev = vblk->vdev;
752 int i;
753
754 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
755 i = sysfs_match_string(virtblk_cache_types, buf);
756 if (i < 0)
757 return i;
758
759 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
760 virtblk_update_cache_mode(vdev);
761 return count;
762 }
763
764 static ssize_t
cache_type_show(struct device * dev,struct device_attribute * attr,char * buf)765 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
766 {
767 struct gendisk *disk = dev_to_disk(dev);
768 struct virtio_blk *vblk = disk->private_data;
769 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
770
771 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
772 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]);
773 }
774
775 static DEVICE_ATTR_RW(cache_type);
776
777 static struct attribute *virtblk_attrs[] = {
778 &dev_attr_serial.attr,
779 &dev_attr_cache_type.attr,
780 NULL,
781 };
782
virtblk_attrs_are_visible(struct kobject * kobj,struct attribute * a,int n)783 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
784 struct attribute *a, int n)
785 {
786 struct device *dev = kobj_to_dev(kobj);
787 struct gendisk *disk = dev_to_disk(dev);
788 struct virtio_blk *vblk = disk->private_data;
789 struct virtio_device *vdev = vblk->vdev;
790
791 if (a == &dev_attr_cache_type.attr &&
792 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
793 return S_IRUGO;
794
795 return a->mode;
796 }
797
798 static const struct attribute_group virtblk_attr_group = {
799 .attrs = virtblk_attrs,
800 .is_visible = virtblk_attrs_are_visible,
801 };
802
803 static const struct attribute_group *virtblk_attr_groups[] = {
804 &virtblk_attr_group,
805 NULL,
806 };
807
virtblk_map_queues(struct blk_mq_tag_set * set)808 static void virtblk_map_queues(struct blk_mq_tag_set *set)
809 {
810 struct virtio_blk *vblk = set->driver_data;
811 int i, qoff;
812
813 for (i = 0, qoff = 0; i < set->nr_maps; i++) {
814 struct blk_mq_queue_map *map = &set->map[i];
815
816 map->nr_queues = vblk->io_queues[i];
817 map->queue_offset = qoff;
818 qoff += map->nr_queues;
819
820 if (map->nr_queues == 0)
821 continue;
822
823 /*
824 * Regular queues have interrupts and hence CPU affinity is
825 * defined by the core virtio code, but polling queues have
826 * no interrupts so we let the block layer assign CPU affinity.
827 */
828 if (i == HCTX_TYPE_POLL)
829 blk_mq_map_queues(&set->map[i]);
830 else
831 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0);
832 }
833 }
834
virtblk_complete_batch(struct io_comp_batch * iob)835 static void virtblk_complete_batch(struct io_comp_batch *iob)
836 {
837 struct request *req;
838
839 rq_list_for_each(&iob->req_list, req) {
840 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req));
841 virtblk_cleanup_cmd(req);
842 }
843 blk_mq_end_request_batch(iob);
844 }
845
virtblk_poll(struct blk_mq_hw_ctx * hctx,struct io_comp_batch * iob)846 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)
847 {
848 struct virtio_blk *vblk = hctx->queue->queuedata;
849 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx);
850 struct virtblk_req *vbr;
851 unsigned long flags;
852 unsigned int len;
853 int found = 0;
854
855 spin_lock_irqsave(&vq->lock, flags);
856
857 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) {
858 struct request *req = blk_mq_rq_from_pdu(vbr);
859
860 found++;
861 if (!blk_mq_add_to_batch(req, iob, vbr->status,
862 virtblk_complete_batch))
863 blk_mq_complete_request(req);
864 }
865
866 if (found)
867 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
868
869 spin_unlock_irqrestore(&vq->lock, flags);
870
871 return found;
872 }
873
874 static const struct blk_mq_ops virtio_mq_ops = {
875 .queue_rq = virtio_queue_rq,
876 .queue_rqs = virtio_queue_rqs,
877 .commit_rqs = virtio_commit_rqs,
878 .complete = virtblk_request_done,
879 .map_queues = virtblk_map_queues,
880 .poll = virtblk_poll,
881 };
882
883 static unsigned int virtblk_queue_depth;
884 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
885
virtblk_probe(struct virtio_device * vdev)886 static int virtblk_probe(struct virtio_device *vdev)
887 {
888 struct virtio_blk *vblk;
889 struct request_queue *q;
890 int err, index;
891
892 u32 v, blk_size, max_size, sg_elems, opt_io_size;
893 u32 max_discard_segs = 0;
894 u32 discard_granularity = 0;
895 u16 min_io_size;
896 u8 physical_block_exp, alignment_offset;
897 unsigned int queue_depth;
898
899 if (!vdev->config->get) {
900 dev_err(&vdev->dev, "%s failure: config access disabled\n",
901 __func__);
902 return -EINVAL;
903 }
904
905 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
906 GFP_KERNEL);
907 if (err < 0)
908 goto out;
909 index = err;
910
911 /* We need to know how many segments before we allocate. */
912 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
913 struct virtio_blk_config, seg_max,
914 &sg_elems);
915
916 /* We need at least one SG element, whatever they say. */
917 if (err || !sg_elems)
918 sg_elems = 1;
919
920 /* Prevent integer overflows and honor max vq size */
921 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2);
922
923 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
924 if (!vblk) {
925 err = -ENOMEM;
926 goto out_free_index;
927 }
928
929 mutex_init(&vblk->vdev_mutex);
930
931 vblk->vdev = vdev;
932
933 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
934
935 err = init_vq(vblk);
936 if (err)
937 goto out_free_vblk;
938
939 /* Default queue sizing is to fill the ring. */
940 if (!virtblk_queue_depth) {
941 queue_depth = vblk->vqs[0].vq->num_free;
942 /* ... but without indirect descs, we use 2 descs per req */
943 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
944 queue_depth /= 2;
945 } else {
946 queue_depth = virtblk_queue_depth;
947 }
948
949 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
950 vblk->tag_set.ops = &virtio_mq_ops;
951 vblk->tag_set.queue_depth = queue_depth;
952 vblk->tag_set.numa_node = NUMA_NO_NODE;
953 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
954 vblk->tag_set.cmd_size =
955 sizeof(struct virtblk_req) +
956 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT;
957 vblk->tag_set.driver_data = vblk;
958 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
959 vblk->tag_set.nr_maps = 1;
960 if (vblk->io_queues[HCTX_TYPE_POLL])
961 vblk->tag_set.nr_maps = 3;
962
963 err = blk_mq_alloc_tag_set(&vblk->tag_set);
964 if (err)
965 goto out_free_vq;
966
967 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk);
968 if (IS_ERR(vblk->disk)) {
969 err = PTR_ERR(vblk->disk);
970 goto out_free_tags;
971 }
972 q = vblk->disk->queue;
973
974 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
975
976 vblk->disk->major = major;
977 vblk->disk->first_minor = index_to_minor(index);
978 vblk->disk->minors = 1 << PART_BITS;
979 vblk->disk->private_data = vblk;
980 vblk->disk->fops = &virtblk_fops;
981 vblk->index = index;
982
983 /* configure queue flush support */
984 virtblk_update_cache_mode(vdev);
985
986 /* If disk is read-only in the host, the guest should obey */
987 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
988 set_disk_ro(vblk->disk, 1);
989
990 /* We can handle whatever the host told us to handle. */
991 blk_queue_max_segments(q, sg_elems);
992
993 /* No real sector limit. */
994 blk_queue_max_hw_sectors(q, -1U);
995
996 max_size = virtio_max_dma_size(vdev);
997
998 /* Host can optionally specify maximum segment size and number of
999 * segments. */
1000 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
1001 struct virtio_blk_config, size_max, &v);
1002 if (!err)
1003 max_size = min(max_size, v);
1004
1005 blk_queue_max_segment_size(q, max_size);
1006
1007 /* Host can optionally specify the block size of the device */
1008 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
1009 struct virtio_blk_config, blk_size,
1010 &blk_size);
1011 if (!err) {
1012 err = blk_validate_block_size(blk_size);
1013 if (err) {
1014 dev_err(&vdev->dev,
1015 "virtio_blk: invalid block size: 0x%x\n",
1016 blk_size);
1017 goto out_cleanup_disk;
1018 }
1019
1020 blk_queue_logical_block_size(q, blk_size);
1021 } else
1022 blk_size = queue_logical_block_size(q);
1023
1024 /* Use topology information if available */
1025 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1026 struct virtio_blk_config, physical_block_exp,
1027 &physical_block_exp);
1028 if (!err && physical_block_exp)
1029 blk_queue_physical_block_size(q,
1030 blk_size * (1 << physical_block_exp));
1031
1032 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1033 struct virtio_blk_config, alignment_offset,
1034 &alignment_offset);
1035 if (!err && alignment_offset)
1036 blk_queue_alignment_offset(q, blk_size * alignment_offset);
1037
1038 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1039 struct virtio_blk_config, min_io_size,
1040 &min_io_size);
1041 if (!err && min_io_size)
1042 blk_queue_io_min(q, blk_size * min_io_size);
1043
1044 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1045 struct virtio_blk_config, opt_io_size,
1046 &opt_io_size);
1047 if (!err && opt_io_size)
1048 blk_queue_io_opt(q, blk_size * opt_io_size);
1049
1050 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
1051 virtio_cread(vdev, struct virtio_blk_config,
1052 discard_sector_alignment, &discard_granularity);
1053
1054 virtio_cread(vdev, struct virtio_blk_config,
1055 max_discard_sectors, &v);
1056 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
1057
1058 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
1059 &max_discard_segs);
1060 }
1061
1062 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
1063 virtio_cread(vdev, struct virtio_blk_config,
1064 max_write_zeroes_sectors, &v);
1065 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
1066 }
1067
1068 /* The discard and secure erase limits are combined since the Linux
1069 * block layer uses the same limit for both commands.
1070 *
1071 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features
1072 * are negotiated, we will use the minimum between the limits.
1073 *
1074 * discard sector alignment is set to the minimum between discard_sector_alignment
1075 * and secure_erase_sector_alignment.
1076 *
1077 * max discard sectors is set to the minimum between max_discard_seg and
1078 * max_secure_erase_seg.
1079 */
1080 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1081
1082 virtio_cread(vdev, struct virtio_blk_config,
1083 secure_erase_sector_alignment, &v);
1084
1085 /* secure_erase_sector_alignment should not be zero, the device should set a
1086 * valid number of sectors.
1087 */
1088 if (!v) {
1089 dev_err(&vdev->dev,
1090 "virtio_blk: secure_erase_sector_alignment can't be 0\n");
1091 err = -EINVAL;
1092 goto out_cleanup_disk;
1093 }
1094
1095 discard_granularity = min_not_zero(discard_granularity, v);
1096
1097 virtio_cread(vdev, struct virtio_blk_config,
1098 max_secure_erase_sectors, &v);
1099
1100 /* max_secure_erase_sectors should not be zero, the device should set a
1101 * valid number of sectors.
1102 */
1103 if (!v) {
1104 dev_err(&vdev->dev,
1105 "virtio_blk: max_secure_erase_sectors can't be 0\n");
1106 err = -EINVAL;
1107 goto out_cleanup_disk;
1108 }
1109
1110 blk_queue_max_secure_erase_sectors(q, v);
1111
1112 virtio_cread(vdev, struct virtio_blk_config,
1113 max_secure_erase_seg, &v);
1114
1115 /* max_secure_erase_seg should not be zero, the device should set a
1116 * valid number of segments
1117 */
1118 if (!v) {
1119 dev_err(&vdev->dev,
1120 "virtio_blk: max_secure_erase_seg can't be 0\n");
1121 err = -EINVAL;
1122 goto out_cleanup_disk;
1123 }
1124
1125 max_discard_segs = min_not_zero(max_discard_segs, v);
1126 }
1127
1128 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) ||
1129 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1130 /* max_discard_seg and discard_granularity will be 0 only
1131 * if max_discard_seg and discard_sector_alignment fields in the virtio
1132 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated.
1133 * In this case, we use default values.
1134 */
1135 if (!max_discard_segs)
1136 max_discard_segs = sg_elems;
1137
1138 blk_queue_max_discard_segments(q,
1139 min(max_discard_segs, MAX_DISCARD_SEGMENTS));
1140
1141 if (discard_granularity)
1142 q->limits.discard_granularity = discard_granularity << SECTOR_SHIFT;
1143 else
1144 q->limits.discard_granularity = blk_size;
1145 }
1146
1147 virtblk_update_capacity(vblk, false);
1148 virtio_device_ready(vdev);
1149
1150 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
1151 if (err)
1152 goto out_cleanup_disk;
1153
1154 return 0;
1155
1156 out_cleanup_disk:
1157 put_disk(vblk->disk);
1158 out_free_tags:
1159 blk_mq_free_tag_set(&vblk->tag_set);
1160 out_free_vq:
1161 vdev->config->del_vqs(vdev);
1162 kfree(vblk->vqs);
1163 out_free_vblk:
1164 kfree(vblk);
1165 out_free_index:
1166 ida_simple_remove(&vd_index_ida, index);
1167 out:
1168 return err;
1169 }
1170
virtblk_remove(struct virtio_device * vdev)1171 static void virtblk_remove(struct virtio_device *vdev)
1172 {
1173 struct virtio_blk *vblk = vdev->priv;
1174
1175 /* Make sure no work handler is accessing the device. */
1176 flush_work(&vblk->config_work);
1177
1178 del_gendisk(vblk->disk);
1179 blk_mq_free_tag_set(&vblk->tag_set);
1180
1181 mutex_lock(&vblk->vdev_mutex);
1182
1183 /* Stop all the virtqueues. */
1184 virtio_reset_device(vdev);
1185
1186 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */
1187 vblk->vdev = NULL;
1188
1189 vdev->config->del_vqs(vdev);
1190 kfree(vblk->vqs);
1191
1192 mutex_unlock(&vblk->vdev_mutex);
1193
1194 put_disk(vblk->disk);
1195 }
1196
1197 #ifdef CONFIG_PM_SLEEP
virtblk_freeze(struct virtio_device * vdev)1198 static int virtblk_freeze(struct virtio_device *vdev)
1199 {
1200 struct virtio_blk *vblk = vdev->priv;
1201
1202 /* Ensure we don't receive any more interrupts */
1203 virtio_reset_device(vdev);
1204
1205 /* Make sure no work handler is accessing the device. */
1206 flush_work(&vblk->config_work);
1207
1208 blk_mq_quiesce_queue(vblk->disk->queue);
1209
1210 vdev->config->del_vqs(vdev);
1211 kfree(vblk->vqs);
1212
1213 return 0;
1214 }
1215
virtblk_restore(struct virtio_device * vdev)1216 static int virtblk_restore(struct virtio_device *vdev)
1217 {
1218 struct virtio_blk *vblk = vdev->priv;
1219 int ret;
1220
1221 ret = init_vq(vdev->priv);
1222 if (ret)
1223 return ret;
1224
1225 virtio_device_ready(vdev);
1226
1227 blk_mq_unquiesce_queue(vblk->disk->queue);
1228 return 0;
1229 }
1230 #endif
1231
1232 static const struct virtio_device_id id_table[] = {
1233 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
1234 { 0 },
1235 };
1236
1237 static unsigned int features_legacy[] = {
1238 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1239 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1240 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1241 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1242 VIRTIO_BLK_F_SECURE_ERASE,
1243 }
1244 ;
1245 static unsigned int features[] = {
1246 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1247 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1248 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1249 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1250 VIRTIO_BLK_F_SECURE_ERASE,
1251 };
1252
1253 static struct virtio_driver virtio_blk = {
1254 .feature_table = features,
1255 .feature_table_size = ARRAY_SIZE(features),
1256 .feature_table_legacy = features_legacy,
1257 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
1258 .driver.name = KBUILD_MODNAME,
1259 .driver.owner = THIS_MODULE,
1260 .id_table = id_table,
1261 .probe = virtblk_probe,
1262 .remove = virtblk_remove,
1263 .config_changed = virtblk_config_changed,
1264 #ifdef CONFIG_PM_SLEEP
1265 .freeze = virtblk_freeze,
1266 .restore = virtblk_restore,
1267 #endif
1268 };
1269
virtio_blk_init(void)1270 static int __init virtio_blk_init(void)
1271 {
1272 int error;
1273
1274 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
1275 if (!virtblk_wq)
1276 return -ENOMEM;
1277
1278 major = register_blkdev(0, "virtblk");
1279 if (major < 0) {
1280 error = major;
1281 goto out_destroy_workqueue;
1282 }
1283
1284 error = register_virtio_driver(&virtio_blk);
1285 if (error)
1286 goto out_unregister_blkdev;
1287 return 0;
1288
1289 out_unregister_blkdev:
1290 unregister_blkdev(major, "virtblk");
1291 out_destroy_workqueue:
1292 destroy_workqueue(virtblk_wq);
1293 return error;
1294 }
1295
virtio_blk_fini(void)1296 static void __exit virtio_blk_fini(void)
1297 {
1298 unregister_virtio_driver(&virtio_blk);
1299 unregister_blkdev(major, "virtblk");
1300 destroy_workqueue(virtblk_wq);
1301 }
1302 module_init(virtio_blk_init);
1303 module_exit(virtio_blk_fini);
1304
1305 MODULE_DEVICE_TABLE(virtio, id_table);
1306 MODULE_DESCRIPTION("Virtio block driver");
1307 MODULE_LICENSE("GPL");
1308
