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drm/panfrost: Remove set but not used variable 'bo'
[linux/fpc-iii.git] / drivers / block / virtio_blk.c
blob54158766334b20cb7eeb0a5ead976843caa3df40
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
19 #define PART_BITS 4
20 #define VQ_NAME_LEN 16
21 #define MAX_DISCARD_SEGMENTS 256u
22
23 static int major;
24 static DEFINE_IDA(vd_index_ida);
25
26 static struct workqueue_struct *virtblk_wq;
27
28 struct virtio_blk_vq {
29 struct virtqueue *vq;
30 spinlock_t lock;
31 char name[VQ_NAME_LEN];
32 } ____cacheline_aligned_in_smp;
33
34 struct virtio_blk {
35 struct virtio_device *vdev;
36
37 /* The disk structure for the kernel. */
38 struct gendisk *disk;
39
40 /* Block layer tags. */
41 struct blk_mq_tag_set tag_set;
42
43 /* Process context for config space updates */
44 struct work_struct config_work;
45
46 /* What host tells us, plus 2 for header & tailer. */
47 unsigned int sg_elems;
48
49 /* Ida index - used to track minor number allocations. */
50 int index;
51
52 /* num of vqs */
53 int num_vqs;
54 struct virtio_blk_vq *vqs;
55 };
56
57 struct virtblk_req {
58 struct virtio_blk_outhdr out_hdr;
59 u8 status;
60 struct scatterlist sg[];
61 };
62
63 static inline blk_status_t virtblk_result(struct virtblk_req *vbr)
64 {
65 switch (vbr->status) {
66 case VIRTIO_BLK_S_OK:
67 return BLK_STS_OK;
68 case VIRTIO_BLK_S_UNSUPP:
69 return BLK_STS_NOTSUPP;
70 default:
71 return BLK_STS_IOERR;
72 }
73 }
74
75 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
76 struct scatterlist *data_sg, bool have_data)
77 {
78 struct scatterlist hdr, status, *sgs[3];
79 unsigned int num_out = 0, num_in = 0;
80
81 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
82 sgs[num_out++] = &hdr;
83
84 if (have_data) {
85 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
86 sgs[num_out++] = data_sg;
87 else
88 sgs[num_out + num_in++] = data_sg;
89 }
90
91 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
92 sgs[num_out + num_in++] = &status;
93
94 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
95 }
96
97 static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap)
98 {
99 unsigned short segments = blk_rq_nr_discard_segments(req);
100 unsigned short n = 0;
101 struct virtio_blk_discard_write_zeroes *range;
102 struct bio *bio;
103 u32 flags = 0;
104
105 if (unmap)
106 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
107
108 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
109 if (!range)
110 return -ENOMEM;
111
112 __rq_for_each_bio(bio, req) {
113 u64 sector = bio->bi_iter.bi_sector;
114 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
115
116 range[n].flags = cpu_to_le32(flags);
117 range[n].num_sectors = cpu_to_le32(num_sectors);
118 range[n].sector = cpu_to_le64(sector);
119 n++;
120 }
121
122 req->special_vec.bv_page = virt_to_page(range);
123 req->special_vec.bv_offset = offset_in_page(range);
124 req->special_vec.bv_len = sizeof(*range) * segments;
125 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
126
127 return 0;
128 }
129
130 static inline void virtblk_request_done(struct request *req)
131 {
132 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
133
134 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
135 kfree(page_address(req->special_vec.bv_page) +
136 req->special_vec.bv_offset);
137 }
138
139 blk_mq_end_request(req, virtblk_result(vbr));
140 }
141
142 static void virtblk_done(struct virtqueue *vq)
143 {
144 struct virtio_blk *vblk = vq->vdev->priv;
145 bool req_done = false;
146 int qid = vq->index;
147 struct virtblk_req *vbr;
148 unsigned long flags;
149 unsigned int len;
150
151 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
152 do {
153 virtqueue_disable_cb(vq);
154 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
155 struct request *req = blk_mq_rq_from_pdu(vbr);
156
157 blk_mq_complete_request(req);
158 req_done = true;
159 }
160 if (unlikely(virtqueue_is_broken(vq)))
161 break;
162 } while (!virtqueue_enable_cb(vq));
163
164 /* In case queue is stopped waiting for more buffers. */
165 if (req_done)
166 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
167 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
168 }
169
170 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
171 {
172 struct virtio_blk *vblk = hctx->queue->queuedata;
173 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
174 bool kick;
175
176 spin_lock_irq(&vq->lock);
177 kick = virtqueue_kick_prepare(vq->vq);
178 spin_unlock_irq(&vq->lock);
179
180 if (kick)
181 virtqueue_notify(vq->vq);
182 }
183
184 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
185 const struct blk_mq_queue_data *bd)
186 {
187 struct virtio_blk *vblk = hctx->queue->queuedata;
188 struct request *req = bd->rq;
189 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
190 unsigned long flags;
191 unsigned int num;
192 int qid = hctx->queue_num;
193 int err;
194 bool notify = false;
195 bool unmap = false;
196 u32 type;
197
198 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
199
200 switch (req_op(req)) {
201 case REQ_OP_READ:
202 case REQ_OP_WRITE:
203 type = 0;
204 break;
205 case REQ_OP_FLUSH:
206 type = VIRTIO_BLK_T_FLUSH;
207 break;
208 case REQ_OP_DISCARD:
209 type = VIRTIO_BLK_T_DISCARD;
210 break;
211 case REQ_OP_WRITE_ZEROES:
212 type = VIRTIO_BLK_T_WRITE_ZEROES;
213 unmap = !(req->cmd_flags & REQ_NOUNMAP);
214 break;
215 case REQ_OP_DRV_IN:
216 type = VIRTIO_BLK_T_GET_ID;
217 break;
218 default:
219 WARN_ON_ONCE(1);
220 return BLK_STS_IOERR;
221 }
222
223 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type);
224 vbr->out_hdr.sector = type ?
225 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req));
226 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req));
227
228 blk_mq_start_request(req);
229
230 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
231 err = virtblk_setup_discard_write_zeroes(req, unmap);
232 if (err)
233 return BLK_STS_RESOURCE;
234 }
235
236 num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
237 if (num) {
238 if (rq_data_dir(req) == WRITE)
239 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
240 else
241 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
242 }
243
244 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
245 err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
246 if (err) {
247 virtqueue_kick(vblk->vqs[qid].vq);
248 blk_mq_stop_hw_queue(hctx);
249 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
250 /* Out of mem doesn't actually happen, since we fall back
251 * to direct descriptors */
252 if (err == -ENOMEM || err == -ENOSPC)
253 return BLK_STS_DEV_RESOURCE;
254 return BLK_STS_IOERR;
255 }
256
257 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
258 notify = true;
259 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
260
261 if (notify)
262 virtqueue_notify(vblk->vqs[qid].vq);
263 return BLK_STS_OK;
264 }
265
266 /* return id (s/n) string for *disk to *id_str
267 */
268 static int virtblk_get_id(struct gendisk *disk, char *id_str)
269 {
270 struct virtio_blk *vblk = disk->private_data;
271 struct request_queue *q = vblk->disk->queue;
272 struct request *req;
273 int err;
274
275 req = blk_get_request(q, REQ_OP_DRV_IN, 0);
276 if (IS_ERR(req))
277 return PTR_ERR(req);
278
279 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
280 if (err)
281 goto out;
282
283 blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
284 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
285 out:
286 blk_put_request(req);
287 return err;
288 }
289
290 /* We provide getgeo only to please some old bootloader/partitioning tools */
291 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
292 {
293 struct virtio_blk *vblk = bd->bd_disk->private_data;
294
295 /* see if the host passed in geometry config */
296 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
297 virtio_cread(vblk->vdev, struct virtio_blk_config,
298 geometry.cylinders, &geo->cylinders);
299 virtio_cread(vblk->vdev, struct virtio_blk_config,
300 geometry.heads, &geo->heads);
301 virtio_cread(vblk->vdev, struct virtio_blk_config,
302 geometry.sectors, &geo->sectors);
303 } else {
304 /* some standard values, similar to sd */
305 geo->heads = 1 << 6;
306 geo->sectors = 1 << 5;
307 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
308 }
309 return 0;
310 }
311
312 static const struct block_device_operations virtblk_fops = {
313 .owner = THIS_MODULE,
314 .getgeo = virtblk_getgeo,
315 };
316
317 static int index_to_minor(int index)
318 {
319 return index << PART_BITS;
320 }
321
322 static int minor_to_index(int minor)
323 {
324 return minor >> PART_BITS;
325 }
326
327 static ssize_t serial_show(struct device *dev,
328 struct device_attribute *attr, char *buf)
329 {
330 struct gendisk *disk = dev_to_disk(dev);
331 int err;
332
333 /* sysfs gives us a PAGE_SIZE buffer */
334 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
335
336 buf[VIRTIO_BLK_ID_BYTES] = '\0';
337 err = virtblk_get_id(disk, buf);
338 if (!err)
339 return strlen(buf);
340
341 if (err == -EIO) /* Unsupported? Make it empty. */
342 return 0;
343
344 return err;
345 }
346
347 static DEVICE_ATTR_RO(serial);
348
349 /* The queue's logical block size must be set before calling this */
350 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
351 {
352 struct virtio_device *vdev = vblk->vdev;
353 struct request_queue *q = vblk->disk->queue;
354 char cap_str_2[10], cap_str_10[10];
355 unsigned long long nblocks;
356 u64 capacity;
357
358 /* Host must always specify the capacity. */
359 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
360
361 /* If capacity is too big, truncate with warning. */
362 if ((sector_t)capacity != capacity) {
363 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
364 (unsigned long long)capacity);
365 capacity = (sector_t)-1;
366 }
367
368 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
369
370 string_get_size(nblocks, queue_logical_block_size(q),
371 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
372 string_get_size(nblocks, queue_logical_block_size(q),
373 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
374
375 dev_notice(&vdev->dev,
376 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
377 vblk->disk->disk_name,
378 resize ? "new size: " : "",
379 nblocks,
380 queue_logical_block_size(q),
381 cap_str_10,
382 cap_str_2);
383
384 set_capacity(vblk->disk, capacity);
385 }
386
387 static void virtblk_config_changed_work(struct work_struct *work)
388 {
389 struct virtio_blk *vblk =
390 container_of(work, struct virtio_blk, config_work);
391 char *envp[] = { "RESIZE=1", NULL };
392
393 virtblk_update_capacity(vblk, true);
394 revalidate_disk(vblk->disk);
395 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
396 }
397
398 static void virtblk_config_changed(struct virtio_device *vdev)
399 {
400 struct virtio_blk *vblk = vdev->priv;
401
402 queue_work(virtblk_wq, &vblk->config_work);
403 }
404
405 static int init_vq(struct virtio_blk *vblk)
406 {
407 int err;
408 int i;
409 vq_callback_t **callbacks;
410 const char **names;
411 struct virtqueue **vqs;
412 unsigned short num_vqs;
413 struct virtio_device *vdev = vblk->vdev;
414 struct irq_affinity desc = { 0, };
415
416 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
417 struct virtio_blk_config, num_queues,
418 &num_vqs);
419 if (err)
420 num_vqs = 1;
421
422 num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
423
424 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
425 if (!vblk->vqs)
426 return -ENOMEM;
427
428 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
429 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
430 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
431 if (!names || !callbacks || !vqs) {
432 err = -ENOMEM;
433 goto out;
434 }
435
436 for (i = 0; i < num_vqs; i++) {
437 callbacks[i] = virtblk_done;
438 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
439 names[i] = vblk->vqs[i].name;
440 }
441
442 /* Discover virtqueues and write information to configuration. */
443 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
444 if (err)
445 goto out;
446
447 for (i = 0; i < num_vqs; i++) {
448 spin_lock_init(&vblk->vqs[i].lock);
449 vblk->vqs[i].vq = vqs[i];
450 }
451 vblk->num_vqs = num_vqs;
452
453 out:
454 kfree(vqs);
455 kfree(callbacks);
456 kfree(names);
457 if (err)
458 kfree(vblk->vqs);
459 return err;
460 }
461
462 /*
463 * Legacy naming scheme used for virtio devices. We are stuck with it for
464 * virtio blk but don't ever use it for any new driver.
465 */
466 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
467 {
468 const int base = 'z' - 'a' + 1;
469 char *begin = buf + strlen(prefix);
470 char *end = buf + buflen;
471 char *p;
472 int unit;
473
474 p = end - 1;
475 *p = '\0';
476 unit = base;
477 do {
478 if (p == begin)
479 return -EINVAL;
480 *--p = 'a' + (index % unit);
481 index = (index / unit) - 1;
482 } while (index >= 0);
483
484 memmove(begin, p, end - p);
485 memcpy(buf, prefix, strlen(prefix));
486
487 return 0;
488 }
489
490 static int virtblk_get_cache_mode(struct virtio_device *vdev)
491 {
492 u8 writeback;
493 int err;
494
495 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
496 struct virtio_blk_config, wce,
497 &writeback);
498
499 /*
500 * If WCE is not configurable and flush is not available,
501 * assume no writeback cache is in use.
502 */
503 if (err)
504 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
505
506 return writeback;
507 }
508
509 static void virtblk_update_cache_mode(struct virtio_device *vdev)
510 {
511 u8 writeback = virtblk_get_cache_mode(vdev);
512 struct virtio_blk *vblk = vdev->priv;
513
514 blk_queue_write_cache(vblk->disk->queue, writeback, false);
515 revalidate_disk(vblk->disk);
516 }
517
518 static const char *const virtblk_cache_types[] = {
519 "write through", "write back"
520 };
521
522 static ssize_t
523 cache_type_store(struct device *dev, struct device_attribute *attr,
524 const char *buf, size_t count)
525 {
526 struct gendisk *disk = dev_to_disk(dev);
527 struct virtio_blk *vblk = disk->private_data;
528 struct virtio_device *vdev = vblk->vdev;
529 int i;
530
531 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
532 i = sysfs_match_string(virtblk_cache_types, buf);
533 if (i < 0)
534 return i;
535
536 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
537 virtblk_update_cache_mode(vdev);
538 return count;
539 }
540
541 static ssize_t
542 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
543 {
544 struct gendisk *disk = dev_to_disk(dev);
545 struct virtio_blk *vblk = disk->private_data;
546 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
547
548 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
549 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
550 }
551
552 static DEVICE_ATTR_RW(cache_type);
553
554 static struct attribute *virtblk_attrs[] = {
555 &dev_attr_serial.attr,
556 &dev_attr_cache_type.attr,
557 NULL,
558 };
559
560 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
561 struct attribute *a, int n)
562 {
563 struct device *dev = container_of(kobj, struct device, kobj);
564 struct gendisk *disk = dev_to_disk(dev);
565 struct virtio_blk *vblk = disk->private_data;
566 struct virtio_device *vdev = vblk->vdev;
567
568 if (a == &dev_attr_cache_type.attr &&
569 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
570 return S_IRUGO;
571
572 return a->mode;
573 }
574
575 static const struct attribute_group virtblk_attr_group = {
576 .attrs = virtblk_attrs,
577 .is_visible = virtblk_attrs_are_visible,
578 };
579
580 static const struct attribute_group *virtblk_attr_groups[] = {
581 &virtblk_attr_group,
582 NULL,
583 };
584
585 static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
586 unsigned int hctx_idx, unsigned int numa_node)
587 {
588 struct virtio_blk *vblk = set->driver_data;
589 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
590
591 sg_init_table(vbr->sg, vblk->sg_elems);
592 return 0;
593 }
594
595 static int virtblk_map_queues(struct blk_mq_tag_set *set)
596 {
597 struct virtio_blk *vblk = set->driver_data;
598
599 return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT],
600 vblk->vdev, 0);
601 }
602
603 static const struct blk_mq_ops virtio_mq_ops = {
604 .queue_rq = virtio_queue_rq,
605 .commit_rqs = virtio_commit_rqs,
606 .complete = virtblk_request_done,
607 .init_request = virtblk_init_request,
608 .map_queues = virtblk_map_queues,
609 };
610
611 static unsigned int virtblk_queue_depth;
612 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
613
614 static int virtblk_probe(struct virtio_device *vdev)
615 {
616 struct virtio_blk *vblk;
617 struct request_queue *q;
618 int err, index;
619
620 u32 v, blk_size, max_size, sg_elems, opt_io_size;
621 u16 min_io_size;
622 u8 physical_block_exp, alignment_offset;
623
624 if (!vdev->config->get) {
625 dev_err(&vdev->dev, "%s failure: config access disabled\n",
626 __func__);
627 return -EINVAL;
628 }
629
630 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
631 GFP_KERNEL);
632 if (err < 0)
633 goto out;
634 index = err;
635
636 /* We need to know how many segments before we allocate. */
637 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
638 struct virtio_blk_config, seg_max,
639 &sg_elems);
640
641 /* We need at least one SG element, whatever they say. */
642 if (err || !sg_elems)
643 sg_elems = 1;
644
645 /* We need an extra sg elements at head and tail. */
646 sg_elems += 2;
647 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
648 if (!vblk) {
649 err = -ENOMEM;
650 goto out_free_index;
651 }
652
653 vblk->vdev = vdev;
654 vblk->sg_elems = sg_elems;
655
656 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
657
658 err = init_vq(vblk);
659 if (err)
660 goto out_free_vblk;
661
662 /* FIXME: How many partitions? How long is a piece of string? */
663 vblk->disk = alloc_disk(1 << PART_BITS);
664 if (!vblk->disk) {
665 err = -ENOMEM;
666 goto out_free_vq;
667 }
668
669 /* Default queue sizing is to fill the ring. */
670 if (!virtblk_queue_depth) {
671 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
672 /* ... but without indirect descs, we use 2 descs per req */
673 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
674 virtblk_queue_depth /= 2;
675 }
676
677 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
678 vblk->tag_set.ops = &virtio_mq_ops;
679 vblk->tag_set.queue_depth = virtblk_queue_depth;
680 vblk->tag_set.numa_node = NUMA_NO_NODE;
681 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
682 vblk->tag_set.cmd_size =
683 sizeof(struct virtblk_req) +
684 sizeof(struct scatterlist) * sg_elems;
685 vblk->tag_set.driver_data = vblk;
686 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
687
688 err = blk_mq_alloc_tag_set(&vblk->tag_set);
689 if (err)
690 goto out_put_disk;
691
692 q = blk_mq_init_queue(&vblk->tag_set);
693 if (IS_ERR(q)) {
694 err = -ENOMEM;
695 goto out_free_tags;
696 }
697 vblk->disk->queue = q;
698
699 q->queuedata = vblk;
700
701 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
702
703 vblk->disk->major = major;
704 vblk->disk->first_minor = index_to_minor(index);
705 vblk->disk->private_data = vblk;
706 vblk->disk->fops = &virtblk_fops;
707 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
708 vblk->index = index;
709
710 /* configure queue flush support */
711 virtblk_update_cache_mode(vdev);
712
713 /* If disk is read-only in the host, the guest should obey */
714 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
715 set_disk_ro(vblk->disk, 1);
716
717 /* We can handle whatever the host told us to handle. */
718 blk_queue_max_segments(q, vblk->sg_elems-2);
719
720 /* No real sector limit. */
721 blk_queue_max_hw_sectors(q, -1U);
722
723 max_size = virtio_max_dma_size(vdev);
724
725 /* Host can optionally specify maximum segment size and number of
726 * segments. */
727 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
728 struct virtio_blk_config, size_max, &v);
729 if (!err)
730 max_size = min(max_size, v);
731
732 blk_queue_max_segment_size(q, max_size);
733
734 /* Host can optionally specify the block size of the device */
735 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
736 struct virtio_blk_config, blk_size,
737 &blk_size);
738 if (!err)
739 blk_queue_logical_block_size(q, blk_size);
740 else
741 blk_size = queue_logical_block_size(q);
742
743 /* Use topology information if available */
744 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
745 struct virtio_blk_config, physical_block_exp,
746 &physical_block_exp);
747 if (!err && physical_block_exp)
748 blk_queue_physical_block_size(q,
749 blk_size * (1 << physical_block_exp));
750
751 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
752 struct virtio_blk_config, alignment_offset,
753 &alignment_offset);
754 if (!err && alignment_offset)
755 blk_queue_alignment_offset(q, blk_size * alignment_offset);
756
757 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
758 struct virtio_blk_config, min_io_size,
759 &min_io_size);
760 if (!err && min_io_size)
761 blk_queue_io_min(q, blk_size * min_io_size);
762
763 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
764 struct virtio_blk_config, opt_io_size,
765 &opt_io_size);
766 if (!err && opt_io_size)
767 blk_queue_io_opt(q, blk_size * opt_io_size);
768
769 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
770 q->limits.discard_granularity = blk_size;
771
772 virtio_cread(vdev, struct virtio_blk_config,
773 discard_sector_alignment, &v);
774 q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
775
776 virtio_cread(vdev, struct virtio_blk_config,
777 max_discard_sectors, &v);
778 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
779
780 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
781 &v);
782 blk_queue_max_discard_segments(q,
783 min_not_zero(v,
784 MAX_DISCARD_SEGMENTS));
785
786 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
787 }
788
789 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
790 virtio_cread(vdev, struct virtio_blk_config,
791 max_write_zeroes_sectors, &v);
792 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
793 }
794
795 virtblk_update_capacity(vblk, false);
796 virtio_device_ready(vdev);
797
798 device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
799 return 0;
800
801 out_free_tags:
802 blk_mq_free_tag_set(&vblk->tag_set);
803 out_put_disk:
804 put_disk(vblk->disk);
805 out_free_vq:
806 vdev->config->del_vqs(vdev);
807 out_free_vblk:
808 kfree(vblk);
809 out_free_index:
810 ida_simple_remove(&vd_index_ida, index);
811 out:
812 return err;
813 }
814
815 static void virtblk_remove(struct virtio_device *vdev)
816 {
817 struct virtio_blk *vblk = vdev->priv;
818 int index = vblk->index;
819 int refc;
820
821 /* Make sure no work handler is accessing the device. */
822 flush_work(&vblk->config_work);
823
824 del_gendisk(vblk->disk);
825 blk_cleanup_queue(vblk->disk->queue);
826
827 blk_mq_free_tag_set(&vblk->tag_set);
828
829 /* Stop all the virtqueues. */
830 vdev->config->reset(vdev);
831
832 refc = kref_read(&disk_to_dev(vblk->disk)->kobj.kref);
833 put_disk(vblk->disk);
834 vdev->config->del_vqs(vdev);
835 kfree(vblk->vqs);
836 kfree(vblk);
837
838 /* Only free device id if we don't have any users */
839 if (refc == 1)
840 ida_simple_remove(&vd_index_ida, index);
841 }
842
843 #ifdef CONFIG_PM_SLEEP
844 static int virtblk_freeze(struct virtio_device *vdev)
845 {
846 struct virtio_blk *vblk = vdev->priv;
847
848 /* Ensure we don't receive any more interrupts */
849 vdev->config->reset(vdev);
850
851 /* Make sure no work handler is accessing the device. */
852 flush_work(&vblk->config_work);
853
854 blk_mq_quiesce_queue(vblk->disk->queue);
855
856 vdev->config->del_vqs(vdev);
857 return 0;
858 }
859
860 static int virtblk_restore(struct virtio_device *vdev)
861 {
862 struct virtio_blk *vblk = vdev->priv;
863 int ret;
864
865 ret = init_vq(vdev->priv);
866 if (ret)
867 return ret;
868
869 virtio_device_ready(vdev);
870
871 blk_mq_unquiesce_queue(vblk->disk->queue);
872 return 0;
873 }
874 #endif
875
876 static const struct virtio_device_id id_table[] = {
877 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
878 { 0 },
879 };
880
881 static unsigned int features_legacy[] = {
882 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
883 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
884 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
885 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
886 }
887 ;
888 static unsigned int features[] = {
889 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
890 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
891 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
892 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
893 };
894
895 static struct virtio_driver virtio_blk = {
896 .feature_table = features,
897 .feature_table_size = ARRAY_SIZE(features),
898 .feature_table_legacy = features_legacy,
899 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
900 .driver.name = KBUILD_MODNAME,
901 .driver.owner = THIS_MODULE,
902 .id_table = id_table,
903 .probe = virtblk_probe,
904 .remove = virtblk_remove,
905 .config_changed = virtblk_config_changed,
906 #ifdef CONFIG_PM_SLEEP
907 .freeze = virtblk_freeze,
908 .restore = virtblk_restore,
909 #endif
910 };
911
912 static int __init init(void)
913 {
914 int error;
915
916 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
917 if (!virtblk_wq)
918 return -ENOMEM;
919
920 major = register_blkdev(0, "virtblk");
921 if (major < 0) {
922 error = major;
923 goto out_destroy_workqueue;
924 }
925
926 error = register_virtio_driver(&virtio_blk);
927 if (error)
928 goto out_unregister_blkdev;
929 return 0;
930
931 out_unregister_blkdev:
932 unregister_blkdev(major, "virtblk");
933 out_destroy_workqueue:
934 destroy_workqueue(virtblk_wq);
935 return error;
936 }
937
938 static void __exit fini(void)
939 {
940 unregister_virtio_driver(&virtio_blk);
941 unregister_blkdev(major, "virtblk");
942 destroy_workqueue(virtblk_wq);
943 }
944 module_init(init);
945 module_exit(fini);
946
947 MODULE_DEVICE_TABLE(virtio, id_table);
948 MODULE_DESCRIPTION("Virtio block driver");
949 MODULE_LICENSE("GPL");
Linux with added FPC-III support