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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions related to setting various queue properties from drivers
4 */
5#include <linux/kernel.h>
6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/bio.h>
9#include <linux/blkdev.h>
10#include <linux/pagemap.h>
11#include <linux/backing-dev-defs.h>
12#include <linux/gcd.h>
13#include <linux/lcm.h>
14#include <linux/jiffies.h>
15#include <linux/gfp.h>
16#include <linux/dma-mapping.h>
17
18#include "blk.h"
19#include "blk-wbt.h"
20
21void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
22{
23 q->rq_timeout = timeout;
24}
25EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
26
27/**
28 * blk_set_default_limits - reset limits to default values
29 * @lim: the queue_limits structure to reset
30 *
31 * Description:
32 * Returns a queue_limit struct to its default state.
33 */
34void blk_set_default_limits(struct queue_limits *lim)
35{
36 lim->max_segments = BLK_MAX_SEGMENTS;
37 lim->max_discard_segments = 1;
38 lim->max_integrity_segments = 0;
39 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
40 lim->virt_boundary_mask = 0;
41 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
42 lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
43 lim->max_dev_sectors = 0;
44 lim->chunk_sectors = 0;
45 lim->max_write_zeroes_sectors = 0;
46 lim->max_zone_append_sectors = 0;
47 lim->max_discard_sectors = 0;
48 lim->max_hw_discard_sectors = 0;
49 lim->max_secure_erase_sectors = 0;
50 lim->discard_granularity = 0;
51 lim->discard_alignment = 0;
52 lim->discard_misaligned = 0;
53 lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
54 lim->bounce = BLK_BOUNCE_NONE;
55 lim->alignment_offset = 0;
56 lim->io_opt = 0;
57 lim->misaligned = 0;
58 lim->zoned = BLK_ZONED_NONE;
59 lim->zone_write_granularity = 0;
60 lim->dma_alignment = 511;
61}
62
63/**
64 * blk_set_stacking_limits - set default limits for stacking devices
65 * @lim: the queue_limits structure to reset
66 *
67 * Description:
68 * Returns a queue_limit struct to its default state. Should be used
69 * by stacking drivers like DM that have no internal limits.
70 */
71void blk_set_stacking_limits(struct queue_limits *lim)
72{
73 blk_set_default_limits(lim);
74
75 /* Inherit limits from component devices */
76 lim->max_segments = USHRT_MAX;
77 lim->max_discard_segments = USHRT_MAX;
78 lim->max_hw_sectors = UINT_MAX;
79 lim->max_segment_size = UINT_MAX;
80 lim->max_sectors = UINT_MAX;
81 lim->max_dev_sectors = UINT_MAX;
82 lim->max_write_zeroes_sectors = UINT_MAX;
83 lim->max_zone_append_sectors = UINT_MAX;
84}
85EXPORT_SYMBOL(blk_set_stacking_limits);
86
87/**
88 * blk_queue_bounce_limit - set bounce buffer limit for queue
89 * @q: the request queue for the device
90 * @bounce: bounce limit to enforce
91 *
92 * Description:
93 * Force bouncing for ISA DMA ranges or highmem.
94 *
95 * DEPRECATED, don't use in new code.
96 **/
97void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce bounce)
98{
99 q->limits.bounce = bounce;
100}
101EXPORT_SYMBOL(blk_queue_bounce_limit);
102
103/**
104 * blk_queue_max_hw_sectors - set max sectors for a request for this queue
105 * @q: the request queue for the device
106 * @max_hw_sectors: max hardware sectors in the usual 512b unit
107 *
108 * Description:
109 * Enables a low level driver to set a hard upper limit,
110 * max_hw_sectors, on the size of requests. max_hw_sectors is set by
111 * the device driver based upon the capabilities of the I/O
112 * controller.
113 *
114 * max_dev_sectors is a hard limit imposed by the storage device for
115 * READ/WRITE requests. It is set by the disk driver.
116 *
117 * max_sectors is a soft limit imposed by the block layer for
118 * filesystem type requests. This value can be overridden on a
119 * per-device basis in /sys/block/<device>/queue/max_sectors_kb.
120 * The soft limit can not exceed max_hw_sectors.
121 **/
122void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
123{
124 struct queue_limits *limits = &q->limits;
125 unsigned int max_sectors;
126
127 if ((max_hw_sectors << 9) < PAGE_SIZE) {
128 max_hw_sectors = 1 << (PAGE_SHIFT - 9);
129 printk(KERN_INFO "%s: set to minimum %d\n",
130 __func__, max_hw_sectors);
131 }
132
133 max_hw_sectors = round_down(max_hw_sectors,
134 limits->logical_block_size >> SECTOR_SHIFT);
135 limits->max_hw_sectors = max_hw_sectors;
136
137 max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
138 max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
139 max_sectors = round_down(max_sectors,
140 limits->logical_block_size >> SECTOR_SHIFT);
141 limits->max_sectors = max_sectors;
142
143 if (!q->disk)
144 return;
145 q->disk->bdi->io_pages = max_sectors >> (PAGE_SHIFT - 9);
146}
147EXPORT_SYMBOL(blk_queue_max_hw_sectors);
148
149/**
150 * blk_queue_chunk_sectors - set size of the chunk for this queue
151 * @q: the request queue for the device
152 * @chunk_sectors: chunk sectors in the usual 512b unit
153 *
154 * Description:
155 * If a driver doesn't want IOs to cross a given chunk size, it can set
156 * this limit and prevent merging across chunks. Note that the block layer
157 * must accept a page worth of data at any offset. So if the crossing of
158 * chunks is a hard limitation in the driver, it must still be prepared
159 * to split single page bios.
160 **/
161void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
162{
163 q->limits.chunk_sectors = chunk_sectors;
164}
165EXPORT_SYMBOL(blk_queue_chunk_sectors);
166
167/**
168 * blk_queue_max_discard_sectors - set max sectors for a single discard
169 * @q: the request queue for the device
170 * @max_discard_sectors: maximum number of sectors to discard
171 **/
172void blk_queue_max_discard_sectors(struct request_queue *q,
173 unsigned int max_discard_sectors)
174{
175 q->limits.max_hw_discard_sectors = max_discard_sectors;
176 q->limits.max_discard_sectors = max_discard_sectors;
177}
178EXPORT_SYMBOL(blk_queue_max_discard_sectors);
179
180/**
181 * blk_queue_max_secure_erase_sectors - set max sectors for a secure erase
182 * @q: the request queue for the device
183 * @max_sectors: maximum number of sectors to secure_erase
184 **/
185void blk_queue_max_secure_erase_sectors(struct request_queue *q,
186 unsigned int max_sectors)
187{
188 q->limits.max_secure_erase_sectors = max_sectors;
189}
190EXPORT_SYMBOL(blk_queue_max_secure_erase_sectors);
191
192/**
193 * blk_queue_max_write_zeroes_sectors - set max sectors for a single
194 * write zeroes
195 * @q: the request queue for the device
196 * @max_write_zeroes_sectors: maximum number of sectors to write per command
197 **/
198void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
199 unsigned int max_write_zeroes_sectors)
200{
201 q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
202}
203EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors);
204
205/**
206 * blk_queue_max_zone_append_sectors - set max sectors for a single zone append
207 * @q: the request queue for the device
208 * @max_zone_append_sectors: maximum number of sectors to write per command
209 **/
210void blk_queue_max_zone_append_sectors(struct request_queue *q,
211 unsigned int max_zone_append_sectors)
212{
213 unsigned int max_sectors;
214
215 if (WARN_ON(!blk_queue_is_zoned(q)))
216 return;
217
218 max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors);
219 max_sectors = min(q->limits.chunk_sectors, max_sectors);
220
221 /*
222 * Signal eventual driver bugs resulting in the max_zone_append sectors limit
223 * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set,
224 * or the max_hw_sectors limit not set.
225 */
226 WARN_ON(!max_sectors);
227
228 q->limits.max_zone_append_sectors = max_sectors;
229}
230EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors);
231
232/**
233 * blk_queue_max_segments - set max hw segments for a request for this queue
234 * @q: the request queue for the device
235 * @max_segments: max number of segments
236 *
237 * Description:
238 * Enables a low level driver to set an upper limit on the number of
239 * hw data segments in a request.
240 **/
241void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
242{
243 if (!max_segments) {
244 max_segments = 1;
245 printk(KERN_INFO "%s: set to minimum %d\n",
246 __func__, max_segments);
247 }
248
249 q->limits.max_segments = max_segments;
250}
251EXPORT_SYMBOL(blk_queue_max_segments);
252
253/**
254 * blk_queue_max_discard_segments - set max segments for discard requests
255 * @q: the request queue for the device
256 * @max_segments: max number of segments
257 *
258 * Description:
259 * Enables a low level driver to set an upper limit on the number of
260 * segments in a discard request.
261 **/
262void blk_queue_max_discard_segments(struct request_queue *q,
263 unsigned short max_segments)
264{
265 q->limits.max_discard_segments = max_segments;
266}
267EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
268
269/**
270 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
271 * @q: the request queue for the device
272 * @max_size: max size of segment in bytes
273 *
274 * Description:
275 * Enables a low level driver to set an upper limit on the size of a
276 * coalesced segment
277 **/
278void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
279{
280 if (max_size < PAGE_SIZE) {
281 max_size = PAGE_SIZE;
282 printk(KERN_INFO "%s: set to minimum %d\n",
283 __func__, max_size);
284 }
285
286 /* see blk_queue_virt_boundary() for the explanation */
287 WARN_ON_ONCE(q->limits.virt_boundary_mask);
288
289 q->limits.max_segment_size = max_size;
290}
291EXPORT_SYMBOL(blk_queue_max_segment_size);
292
293/**
294 * blk_queue_logical_block_size - set logical block size for the queue
295 * @q: the request queue for the device
296 * @size: the logical block size, in bytes
297 *
298 * Description:
299 * This should be set to the lowest possible block size that the
300 * storage device can address. The default of 512 covers most
301 * hardware.
302 **/
303void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
304{
305 struct queue_limits *limits = &q->limits;
306
307 limits->logical_block_size = size;
308
309 if (limits->physical_block_size < size)
310 limits->physical_block_size = size;
311
312 if (limits->io_min < limits->physical_block_size)
313 limits->io_min = limits->physical_block_size;
314
315 limits->max_hw_sectors =
316 round_down(limits->max_hw_sectors, size >> SECTOR_SHIFT);
317 limits->max_sectors =
318 round_down(limits->max_sectors, size >> SECTOR_SHIFT);
319}
320EXPORT_SYMBOL(blk_queue_logical_block_size);
321
322/**
323 * blk_queue_physical_block_size - set physical block size for the queue
324 * @q: the request queue for the device
325 * @size: the physical block size, in bytes
326 *
327 * Description:
328 * This should be set to the lowest possible sector size that the
329 * hardware can operate on without reverting to read-modify-write
330 * operations.
331 */
332void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
333{
334 q->limits.physical_block_size = size;
335
336 if (q->limits.physical_block_size < q->limits.logical_block_size)
337 q->limits.physical_block_size = q->limits.logical_block_size;
338
339 if (q->limits.io_min < q->limits.physical_block_size)
340 q->limits.io_min = q->limits.physical_block_size;
341}
342EXPORT_SYMBOL(blk_queue_physical_block_size);
343
344/**
345 * blk_queue_zone_write_granularity - set zone write granularity for the queue
346 * @q: the request queue for the zoned device
347 * @size: the zone write granularity size, in bytes
348 *
349 * Description:
350 * This should be set to the lowest possible size allowing to write in
351 * sequential zones of a zoned block device.
352 */
353void blk_queue_zone_write_granularity(struct request_queue *q,
354 unsigned int size)
355{
356 if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
357 return;
358
359 q->limits.zone_write_granularity = size;
360
361 if (q->limits.zone_write_granularity < q->limits.logical_block_size)
362 q->limits.zone_write_granularity = q->limits.logical_block_size;
363}
364EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity);
365
366/**
367 * blk_queue_alignment_offset - set physical block alignment offset
368 * @q: the request queue for the device
369 * @offset: alignment offset in bytes
370 *
371 * Description:
372 * Some devices are naturally misaligned to compensate for things like
373 * the legacy DOS partition table 63-sector offset. Low-level drivers
374 * should call this function for devices whose first sector is not
375 * naturally aligned.
376 */
377void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
378{
379 q->limits.alignment_offset =
380 offset & (q->limits.physical_block_size - 1);
381 q->limits.misaligned = 0;
382}
383EXPORT_SYMBOL(blk_queue_alignment_offset);
384
385void disk_update_readahead(struct gendisk *disk)
386{
387 struct request_queue *q = disk->queue;
388
389 /*
390 * For read-ahead of large files to be effective, we need to read ahead
391 * at least twice the optimal I/O size.
392 */
393 disk->bdi->ra_pages =
394 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
395 disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9);
396}
397EXPORT_SYMBOL_GPL(disk_update_readahead);
398
399/**
400 * blk_limits_io_min - set minimum request size for a device
401 * @limits: the queue limits
402 * @min: smallest I/O size in bytes
403 *
404 * Description:
405 * Some devices have an internal block size bigger than the reported
406 * hardware sector size. This function can be used to signal the
407 * smallest I/O the device can perform without incurring a performance
408 * penalty.
409 */
410void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
411{
412 limits->io_min = min;
413
414 if (limits->io_min < limits->logical_block_size)
415 limits->io_min = limits->logical_block_size;
416
417 if (limits->io_min < limits->physical_block_size)
418 limits->io_min = limits->physical_block_size;
419}
420EXPORT_SYMBOL(blk_limits_io_min);
421
422/**
423 * blk_queue_io_min - set minimum request size for the queue
424 * @q: the request queue for the device
425 * @min: smallest I/O size in bytes
426 *
427 * Description:
428 * Storage devices may report a granularity or preferred minimum I/O
429 * size which is the smallest request the device can perform without
430 * incurring a performance penalty. For disk drives this is often the
431 * physical block size. For RAID arrays it is often the stripe chunk
432 * size. A properly aligned multiple of minimum_io_size is the
433 * preferred request size for workloads where a high number of I/O
434 * operations is desired.
435 */
436void blk_queue_io_min(struct request_queue *q, unsigned int min)
437{
438 blk_limits_io_min(&q->limits, min);
439}
440EXPORT_SYMBOL(blk_queue_io_min);
441
442/**
443 * blk_limits_io_opt - set optimal request size for a device
444 * @limits: the queue limits
445 * @opt: smallest I/O size in bytes
446 *
447 * Description:
448 * Storage devices may report an optimal I/O size, which is the
449 * device's preferred unit for sustained I/O. This is rarely reported
450 * for disk drives. For RAID arrays it is usually the stripe width or
451 * the internal track size. A properly aligned multiple of
452 * optimal_io_size is the preferred request size for workloads where
453 * sustained throughput is desired.
454 */
455void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
456{
457 limits->io_opt = opt;
458}
459EXPORT_SYMBOL(blk_limits_io_opt);
460
461/**
462 * blk_queue_io_opt - set optimal request size for the queue
463 * @q: the request queue for the device
464 * @opt: optimal request size in bytes
465 *
466 * Description:
467 * Storage devices may report an optimal I/O size, which is the
468 * device's preferred unit for sustained I/O. This is rarely reported
469 * for disk drives. For RAID arrays it is usually the stripe width or
470 * the internal track size. A properly aligned multiple of
471 * optimal_io_size is the preferred request size for workloads where
472 * sustained throughput is desired.
473 */
474void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
475{
476 blk_limits_io_opt(&q->limits, opt);
477 if (!q->disk)
478 return;
479 q->disk->bdi->ra_pages =
480 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
481}
482EXPORT_SYMBOL(blk_queue_io_opt);
483
484static int queue_limit_alignment_offset(const struct queue_limits *lim,
485 sector_t sector)
486{
487 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
488 unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
489 << SECTOR_SHIFT;
490
491 return (granularity + lim->alignment_offset - alignment) % granularity;
492}
493
494static unsigned int queue_limit_discard_alignment(
495 const struct queue_limits *lim, sector_t sector)
496{
497 unsigned int alignment, granularity, offset;
498
499 if (!lim->max_discard_sectors)
500 return 0;
501
502 /* Why are these in bytes, not sectors? */
503 alignment = lim->discard_alignment >> SECTOR_SHIFT;
504 granularity = lim->discard_granularity >> SECTOR_SHIFT;
505 if (!granularity)
506 return 0;
507
508 /* Offset of the partition start in 'granularity' sectors */
509 offset = sector_div(sector, granularity);
510
511 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
512 offset = (granularity + alignment - offset) % granularity;
513
514 /* Turn it back into bytes, gaah */
515 return offset << SECTOR_SHIFT;
516}
517
518static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
519{
520 sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
521 if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
522 sectors = PAGE_SIZE >> SECTOR_SHIFT;
523 return sectors;
524}
525
526/**
527 * blk_stack_limits - adjust queue_limits for stacked devices
528 * @t: the stacking driver limits (top device)
529 * @b: the underlying queue limits (bottom, component device)
530 * @start: first data sector within component device
531 *
532 * Description:
533 * This function is used by stacking drivers like MD and DM to ensure
534 * that all component devices have compatible block sizes and
535 * alignments. The stacking driver must provide a queue_limits
536 * struct (top) and then iteratively call the stacking function for
537 * all component (bottom) devices. The stacking function will
538 * attempt to combine the values and ensure proper alignment.
539 *
540 * Returns 0 if the top and bottom queue_limits are compatible. The
541 * top device's block sizes and alignment offsets may be adjusted to
542 * ensure alignment with the bottom device. If no compatible sizes
543 * and alignments exist, -1 is returned and the resulting top
544 * queue_limits will have the misaligned flag set to indicate that
545 * the alignment_offset is undefined.
546 */
547int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
548 sector_t start)
549{
550 unsigned int top, bottom, alignment, ret = 0;
551
552 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
553 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
554 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
555 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
556 b->max_write_zeroes_sectors);
557 t->max_zone_append_sectors = min(t->max_zone_append_sectors,
558 b->max_zone_append_sectors);
559 t->bounce = max(t->bounce, b->bounce);
560
561 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
562 b->seg_boundary_mask);
563 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
564 b->virt_boundary_mask);
565
566 t->max_segments = min_not_zero(t->max_segments, b->max_segments);
567 t->max_discard_segments = min_not_zero(t->max_discard_segments,
568 b->max_discard_segments);
569 t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
570 b->max_integrity_segments);
571
572 t->max_segment_size = min_not_zero(t->max_segment_size,
573 b->max_segment_size);
574
575 t->misaligned |= b->misaligned;
576
577 alignment = queue_limit_alignment_offset(b, start);
578
579 /* Bottom device has different alignment. Check that it is
580 * compatible with the current top alignment.
581 */
582 if (t->alignment_offset != alignment) {
583
584 top = max(t->physical_block_size, t->io_min)
585 + t->alignment_offset;
586 bottom = max(b->physical_block_size, b->io_min) + alignment;
587
588 /* Verify that top and bottom intervals line up */
589 if (max(top, bottom) % min(top, bottom)) {
590 t->misaligned = 1;
591 ret = -1;
592 }
593 }
594
595 t->logical_block_size = max(t->logical_block_size,
596 b->logical_block_size);
597
598 t->physical_block_size = max(t->physical_block_size,
599 b->physical_block_size);
600
601 t->io_min = max(t->io_min, b->io_min);
602 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
603 t->dma_alignment = max(t->dma_alignment, b->dma_alignment);
604
605 /* Set non-power-of-2 compatible chunk_sectors boundary */
606 if (b->chunk_sectors)
607 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
608
609 /* Physical block size a multiple of the logical block size? */
610 if (t->physical_block_size & (t->logical_block_size - 1)) {
611 t->physical_block_size = t->logical_block_size;
612 t->misaligned = 1;
613 ret = -1;
614 }
615
616 /* Minimum I/O a multiple of the physical block size? */
617 if (t->io_min & (t->physical_block_size - 1)) {
618 t->io_min = t->physical_block_size;
619 t->misaligned = 1;
620 ret = -1;
621 }
622
623 /* Optimal I/O a multiple of the physical block size? */
624 if (t->io_opt & (t->physical_block_size - 1)) {
625 t->io_opt = 0;
626 t->misaligned = 1;
627 ret = -1;
628 }
629
630 /* chunk_sectors a multiple of the physical block size? */
631 if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
632 t->chunk_sectors = 0;
633 t->misaligned = 1;
634 ret = -1;
635 }
636
637 t->raid_partial_stripes_expensive =
638 max(t->raid_partial_stripes_expensive,
639 b->raid_partial_stripes_expensive);
640
641 /* Find lowest common alignment_offset */
642 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
643 % max(t->physical_block_size, t->io_min);
644
645 /* Verify that new alignment_offset is on a logical block boundary */
646 if (t->alignment_offset & (t->logical_block_size - 1)) {
647 t->misaligned = 1;
648 ret = -1;
649 }
650
651 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
652 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
653 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
654
655 /* Discard alignment and granularity */
656 if (b->discard_granularity) {
657 alignment = queue_limit_discard_alignment(b, start);
658
659 if (t->discard_granularity != 0 &&
660 t->discard_alignment != alignment) {
661 top = t->discard_granularity + t->discard_alignment;
662 bottom = b->discard_granularity + alignment;
663
664 /* Verify that top and bottom intervals line up */
665 if ((max(top, bottom) % min(top, bottom)) != 0)
666 t->discard_misaligned = 1;
667 }
668
669 t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
670 b->max_discard_sectors);
671 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
672 b->max_hw_discard_sectors);
673 t->discard_granularity = max(t->discard_granularity,
674 b->discard_granularity);
675 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
676 t->discard_granularity;
677 }
678 t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors,
679 b->max_secure_erase_sectors);
680 t->zone_write_granularity = max(t->zone_write_granularity,
681 b->zone_write_granularity);
682 t->zoned = max(t->zoned, b->zoned);
683 return ret;
684}
685EXPORT_SYMBOL(blk_stack_limits);
686
687/**
688 * disk_stack_limits - adjust queue limits for stacked drivers
689 * @disk: MD/DM gendisk (top)
690 * @bdev: the underlying block device (bottom)
691 * @offset: offset to beginning of data within component device
692 *
693 * Description:
694 * Merges the limits for a top level gendisk and a bottom level
695 * block_device.
696 */
697void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
698 sector_t offset)
699{
700 struct request_queue *t = disk->queue;
701
702 if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
703 get_start_sect(bdev) + (offset >> 9)) < 0)
704 pr_notice("%s: Warning: Device %pg is misaligned\n",
705 disk->disk_name, bdev);
706
707 disk_update_readahead(disk);
708}
709EXPORT_SYMBOL(disk_stack_limits);
710
711/**
712 * blk_queue_update_dma_pad - update pad mask
713 * @q: the request queue for the device
714 * @mask: pad mask
715 *
716 * Update dma pad mask.
717 *
718 * Appending pad buffer to a request modifies the last entry of a
719 * scatter list such that it includes the pad buffer.
720 **/
721void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
722{
723 if (mask > q->dma_pad_mask)
724 q->dma_pad_mask = mask;
725}
726EXPORT_SYMBOL(blk_queue_update_dma_pad);
727
728/**
729 * blk_queue_segment_boundary - set boundary rules for segment merging
730 * @q: the request queue for the device
731 * @mask: the memory boundary mask
732 **/
733void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
734{
735 if (mask < PAGE_SIZE - 1) {
736 mask = PAGE_SIZE - 1;
737 printk(KERN_INFO "%s: set to minimum %lx\n",
738 __func__, mask);
739 }
740
741 q->limits.seg_boundary_mask = mask;
742}
743EXPORT_SYMBOL(blk_queue_segment_boundary);
744
745/**
746 * blk_queue_virt_boundary - set boundary rules for bio merging
747 * @q: the request queue for the device
748 * @mask: the memory boundary mask
749 **/
750void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
751{
752 q->limits.virt_boundary_mask = mask;
753
754 /*
755 * Devices that require a virtual boundary do not support scatter/gather
756 * I/O natively, but instead require a descriptor list entry for each
757 * page (which might not be idential to the Linux PAGE_SIZE). Because
758 * of that they are not limited by our notion of "segment size".
759 */
760 if (mask)
761 q->limits.max_segment_size = UINT_MAX;
762}
763EXPORT_SYMBOL(blk_queue_virt_boundary);
764
765/**
766 * blk_queue_dma_alignment - set dma length and memory alignment
767 * @q: the request queue for the device
768 * @mask: alignment mask
769 *
770 * description:
771 * set required memory and length alignment for direct dma transactions.
772 * this is used when building direct io requests for the queue.
773 *
774 **/
775void blk_queue_dma_alignment(struct request_queue *q, int mask)
776{
777 q->limits.dma_alignment = mask;
778}
779EXPORT_SYMBOL(blk_queue_dma_alignment);
780
781/**
782 * blk_queue_update_dma_alignment - update dma length and memory alignment
783 * @q: the request queue for the device
784 * @mask: alignment mask
785 *
786 * description:
787 * update required memory and length alignment for direct dma transactions.
788 * If the requested alignment is larger than the current alignment, then
789 * the current queue alignment is updated to the new value, otherwise it
790 * is left alone. The design of this is to allow multiple objects
791 * (driver, device, transport etc) to set their respective
792 * alignments without having them interfere.
793 *
794 **/
795void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
796{
797 BUG_ON(mask > PAGE_SIZE);
798
799 if (mask > q->limits.dma_alignment)
800 q->limits.dma_alignment = mask;
801}
802EXPORT_SYMBOL(blk_queue_update_dma_alignment);
803
804/**
805 * blk_set_queue_depth - tell the block layer about the device queue depth
806 * @q: the request queue for the device
807 * @depth: queue depth
808 *
809 */
810void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
811{
812 q->queue_depth = depth;
813 rq_qos_queue_depth_changed(q);
814}
815EXPORT_SYMBOL(blk_set_queue_depth);
816
817/**
818 * blk_queue_write_cache - configure queue's write cache
819 * @q: the request queue for the device
820 * @wc: write back cache on or off
821 * @fua: device supports FUA writes, if true
822 *
823 * Tell the block layer about the write cache of @q.
824 */
825void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
826{
827 if (wc)
828 blk_queue_flag_set(QUEUE_FLAG_WC, q);
829 else
830 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
831 if (fua)
832 blk_queue_flag_set(QUEUE_FLAG_FUA, q);
833 else
834 blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
835
836 wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
837}
838EXPORT_SYMBOL_GPL(blk_queue_write_cache);
839
840/**
841 * blk_queue_required_elevator_features - Set a queue required elevator features
842 * @q: the request queue for the target device
843 * @features: Required elevator features OR'ed together
844 *
845 * Tell the block layer that for the device controlled through @q, only the
846 * only elevators that can be used are those that implement at least the set of
847 * features specified by @features.
848 */
849void blk_queue_required_elevator_features(struct request_queue *q,
850 unsigned int features)
851{
852 q->required_elevator_features = features;
853}
854EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features);
855
856/**
857 * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
858 * @q: the request queue for the device
859 * @dev: the device pointer for dma
860 *
861 * Tell the block layer about merging the segments by dma map of @q.
862 */
863bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
864 struct device *dev)
865{
866 unsigned long boundary = dma_get_merge_boundary(dev);
867
868 if (!boundary)
869 return false;
870
871 /* No need to update max_segment_size. see blk_queue_virt_boundary() */
872 blk_queue_virt_boundary(q, boundary);
873
874 return true;
875}
876EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
877
878static bool disk_has_partitions(struct gendisk *disk)
879{
880 unsigned long idx;
881 struct block_device *part;
882 bool ret = false;
883
884 rcu_read_lock();
885 xa_for_each(&disk->part_tbl, idx, part) {
886 if (bdev_is_partition(part)) {
887 ret = true;
888 break;
889 }
890 }
891 rcu_read_unlock();
892
893 return ret;
894}
895
896/**
897 * disk_set_zoned - configure the zoned model for a disk
898 * @disk: the gendisk of the queue to configure
899 * @model: the zoned model to set
900 *
901 * Set the zoned model of @disk to @model.
902 *
903 * When @model is BLK_ZONED_HM (host managed), this should be called only
904 * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option).
905 * If @model specifies BLK_ZONED_HA (host aware), the effective model used
906 * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions
907 * on the disk.
908 */
909void disk_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
910{
911 struct request_queue *q = disk->queue;
912
913 switch (model) {
914 case BLK_ZONED_HM:
915 /*
916 * Host managed devices are supported only if
917 * CONFIG_BLK_DEV_ZONED is enabled.
918 */
919 WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));
920 break;
921 case BLK_ZONED_HA:
922 /*
923 * Host aware devices can be treated either as regular block
924 * devices (similar to drive managed devices) or as zoned block
925 * devices to take advantage of the zone command set, similarly
926 * to host managed devices. We try the latter if there are no
927 * partitions and zoned block device support is enabled, else
928 * we do nothing special as far as the block layer is concerned.
929 */
930 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||
931 disk_has_partitions(disk))
932 model = BLK_ZONED_NONE;
933 break;
934 case BLK_ZONED_NONE:
935 default:
936 if (WARN_ON_ONCE(model != BLK_ZONED_NONE))
937 model = BLK_ZONED_NONE;
938 break;
939 }
940
941 q->limits.zoned = model;
942 if (model != BLK_ZONED_NONE) {
943 /*
944 * Set the zone write granularity to the device logical block
945 * size by default. The driver can change this value if needed.
946 */
947 blk_queue_zone_write_granularity(q,
948 queue_logical_block_size(q));
949 } else {
950 disk_clear_zone_settings(disk);
951 }
952}
953EXPORT_SYMBOL_GPL(disk_set_zoned);
954
955int bdev_alignment_offset(struct block_device *bdev)
956{
957 struct request_queue *q = bdev_get_queue(bdev);
958
959 if (q->limits.misaligned)
960 return -1;
961 if (bdev_is_partition(bdev))
962 return queue_limit_alignment_offset(&q->limits,
963 bdev->bd_start_sect);
964 return q->limits.alignment_offset;
965}
966EXPORT_SYMBOL_GPL(bdev_alignment_offset);
967
968unsigned int bdev_discard_alignment(struct block_device *bdev)
969{
970 struct request_queue *q = bdev_get_queue(bdev);
971
972 if (bdev_is_partition(bdev))
973 return queue_limit_discard_alignment(&q->limits,
974 bdev->bd_start_sect);
975 return q->limits.discard_alignment;
976}
977EXPORT_SYMBOL_GPL(bdev_discard_alignment);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions related to setting various queue properties from drivers
4 */
5#include <linux/kernel.h>
6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/bio.h>
9#include <linux/blkdev.h>
10#include <linux/pagemap.h>
11#include <linux/gcd.h>
12#include <linux/lcm.h>
13#include <linux/jiffies.h>
14#include <linux/gfp.h>
15#include <linux/dma-mapping.h>
16
17#include "blk.h"
18#include "blk-wbt.h"
19
20void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
21{
22 q->rq_timeout = timeout;
23}
24EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
25
26/**
27 * blk_set_default_limits - reset limits to default values
28 * @lim: the queue_limits structure to reset
29 *
30 * Description:
31 * Returns a queue_limit struct to its default state.
32 */
33void blk_set_default_limits(struct queue_limits *lim)
34{
35 lim->max_segments = BLK_MAX_SEGMENTS;
36 lim->max_discard_segments = 1;
37 lim->max_integrity_segments = 0;
38 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
39 lim->virt_boundary_mask = 0;
40 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
41 lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
42 lim->max_dev_sectors = 0;
43 lim->chunk_sectors = 0;
44 lim->max_write_same_sectors = 0;
45 lim->max_write_zeroes_sectors = 0;
46 lim->max_zone_append_sectors = 0;
47 lim->max_discard_sectors = 0;
48 lim->max_hw_discard_sectors = 0;
49 lim->discard_granularity = 0;
50 lim->discard_alignment = 0;
51 lim->discard_misaligned = 0;
52 lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
53 lim->bounce = BLK_BOUNCE_NONE;
54 lim->alignment_offset = 0;
55 lim->io_opt = 0;
56 lim->misaligned = 0;
57 lim->zoned = BLK_ZONED_NONE;
58 lim->zone_write_granularity = 0;
59}
60EXPORT_SYMBOL(blk_set_default_limits);
61
62/**
63 * blk_set_stacking_limits - set default limits for stacking devices
64 * @lim: the queue_limits structure to reset
65 *
66 * Description:
67 * Returns a queue_limit struct to its default state. Should be used
68 * by stacking drivers like DM that have no internal limits.
69 */
70void blk_set_stacking_limits(struct queue_limits *lim)
71{
72 blk_set_default_limits(lim);
73
74 /* Inherit limits from component devices */
75 lim->max_segments = USHRT_MAX;
76 lim->max_discard_segments = USHRT_MAX;
77 lim->max_hw_sectors = UINT_MAX;
78 lim->max_segment_size = UINT_MAX;
79 lim->max_sectors = UINT_MAX;
80 lim->max_dev_sectors = UINT_MAX;
81 lim->max_write_same_sectors = UINT_MAX;
82 lim->max_write_zeroes_sectors = UINT_MAX;
83 lim->max_zone_append_sectors = UINT_MAX;
84}
85EXPORT_SYMBOL(blk_set_stacking_limits);
86
87/**
88 * blk_queue_bounce_limit - set bounce buffer limit for queue
89 * @q: the request queue for the device
90 * @bounce: bounce limit to enforce
91 *
92 * Description:
93 * Force bouncing for ISA DMA ranges or highmem.
94 *
95 * DEPRECATED, don't use in new code.
96 **/
97void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce bounce)
98{
99 q->limits.bounce = bounce;
100}
101EXPORT_SYMBOL(blk_queue_bounce_limit);
102
103/**
104 * blk_queue_max_hw_sectors - set max sectors for a request for this queue
105 * @q: the request queue for the device
106 * @max_hw_sectors: max hardware sectors in the usual 512b unit
107 *
108 * Description:
109 * Enables a low level driver to set a hard upper limit,
110 * max_hw_sectors, on the size of requests. max_hw_sectors is set by
111 * the device driver based upon the capabilities of the I/O
112 * controller.
113 *
114 * max_dev_sectors is a hard limit imposed by the storage device for
115 * READ/WRITE requests. It is set by the disk driver.
116 *
117 * max_sectors is a soft limit imposed by the block layer for
118 * filesystem type requests. This value can be overridden on a
119 * per-device basis in /sys/block/<device>/queue/max_sectors_kb.
120 * The soft limit can not exceed max_hw_sectors.
121 **/
122void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
123{
124 struct queue_limits *limits = &q->limits;
125 unsigned int max_sectors;
126
127 if ((max_hw_sectors << 9) < PAGE_SIZE) {
128 max_hw_sectors = 1 << (PAGE_SHIFT - 9);
129 printk(KERN_INFO "%s: set to minimum %d\n",
130 __func__, max_hw_sectors);
131 }
132
133 max_hw_sectors = round_down(max_hw_sectors,
134 limits->logical_block_size >> SECTOR_SHIFT);
135 limits->max_hw_sectors = max_hw_sectors;
136
137 max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
138 max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
139 max_sectors = round_down(max_sectors,
140 limits->logical_block_size >> SECTOR_SHIFT);
141 limits->max_sectors = max_sectors;
142
143 q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - 9);
144}
145EXPORT_SYMBOL(blk_queue_max_hw_sectors);
146
147/**
148 * blk_queue_chunk_sectors - set size of the chunk for this queue
149 * @q: the request queue for the device
150 * @chunk_sectors: chunk sectors in the usual 512b unit
151 *
152 * Description:
153 * If a driver doesn't want IOs to cross a given chunk size, it can set
154 * this limit and prevent merging across chunks. Note that the block layer
155 * must accept a page worth of data at any offset. So if the crossing of
156 * chunks is a hard limitation in the driver, it must still be prepared
157 * to split single page bios.
158 **/
159void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
160{
161 q->limits.chunk_sectors = chunk_sectors;
162}
163EXPORT_SYMBOL(blk_queue_chunk_sectors);
164
165/**
166 * blk_queue_max_discard_sectors - set max sectors for a single discard
167 * @q: the request queue for the device
168 * @max_discard_sectors: maximum number of sectors to discard
169 **/
170void blk_queue_max_discard_sectors(struct request_queue *q,
171 unsigned int max_discard_sectors)
172{
173 q->limits.max_hw_discard_sectors = max_discard_sectors;
174 q->limits.max_discard_sectors = max_discard_sectors;
175}
176EXPORT_SYMBOL(blk_queue_max_discard_sectors);
177
178/**
179 * blk_queue_max_write_same_sectors - set max sectors for a single write same
180 * @q: the request queue for the device
181 * @max_write_same_sectors: maximum number of sectors to write per command
182 **/
183void blk_queue_max_write_same_sectors(struct request_queue *q,
184 unsigned int max_write_same_sectors)
185{
186 q->limits.max_write_same_sectors = max_write_same_sectors;
187}
188EXPORT_SYMBOL(blk_queue_max_write_same_sectors);
189
190/**
191 * blk_queue_max_write_zeroes_sectors - set max sectors for a single
192 * write zeroes
193 * @q: the request queue for the device
194 * @max_write_zeroes_sectors: maximum number of sectors to write per command
195 **/
196void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
197 unsigned int max_write_zeroes_sectors)
198{
199 q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
200}
201EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors);
202
203/**
204 * blk_queue_max_zone_append_sectors - set max sectors for a single zone append
205 * @q: the request queue for the device
206 * @max_zone_append_sectors: maximum number of sectors to write per command
207 **/
208void blk_queue_max_zone_append_sectors(struct request_queue *q,
209 unsigned int max_zone_append_sectors)
210{
211 unsigned int max_sectors;
212
213 if (WARN_ON(!blk_queue_is_zoned(q)))
214 return;
215
216 max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors);
217 max_sectors = min(q->limits.chunk_sectors, max_sectors);
218
219 /*
220 * Signal eventual driver bugs resulting in the max_zone_append sectors limit
221 * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set,
222 * or the max_hw_sectors limit not set.
223 */
224 WARN_ON(!max_sectors);
225
226 q->limits.max_zone_append_sectors = max_sectors;
227}
228EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors);
229
230/**
231 * blk_queue_max_segments - set max hw segments for a request for this queue
232 * @q: the request queue for the device
233 * @max_segments: max number of segments
234 *
235 * Description:
236 * Enables a low level driver to set an upper limit on the number of
237 * hw data segments in a request.
238 **/
239void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
240{
241 if (!max_segments) {
242 max_segments = 1;
243 printk(KERN_INFO "%s: set to minimum %d\n",
244 __func__, max_segments);
245 }
246
247 q->limits.max_segments = max_segments;
248}
249EXPORT_SYMBOL(blk_queue_max_segments);
250
251/**
252 * blk_queue_max_discard_segments - set max segments for discard requests
253 * @q: the request queue for the device
254 * @max_segments: max number of segments
255 *
256 * Description:
257 * Enables a low level driver to set an upper limit on the number of
258 * segments in a discard request.
259 **/
260void blk_queue_max_discard_segments(struct request_queue *q,
261 unsigned short max_segments)
262{
263 q->limits.max_discard_segments = max_segments;
264}
265EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
266
267/**
268 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
269 * @q: the request queue for the device
270 * @max_size: max size of segment in bytes
271 *
272 * Description:
273 * Enables a low level driver to set an upper limit on the size of a
274 * coalesced segment
275 **/
276void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
277{
278 if (max_size < PAGE_SIZE) {
279 max_size = PAGE_SIZE;
280 printk(KERN_INFO "%s: set to minimum %d\n",
281 __func__, max_size);
282 }
283
284 /* see blk_queue_virt_boundary() for the explanation */
285 WARN_ON_ONCE(q->limits.virt_boundary_mask);
286
287 q->limits.max_segment_size = max_size;
288}
289EXPORT_SYMBOL(blk_queue_max_segment_size);
290
291/**
292 * blk_queue_logical_block_size - set logical block size for the queue
293 * @q: the request queue for the device
294 * @size: the logical block size, in bytes
295 *
296 * Description:
297 * This should be set to the lowest possible block size that the
298 * storage device can address. The default of 512 covers most
299 * hardware.
300 **/
301void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
302{
303 struct queue_limits *limits = &q->limits;
304
305 limits->logical_block_size = size;
306
307 if (limits->physical_block_size < size)
308 limits->physical_block_size = size;
309
310 if (limits->io_min < limits->physical_block_size)
311 limits->io_min = limits->physical_block_size;
312
313 limits->max_hw_sectors =
314 round_down(limits->max_hw_sectors, size >> SECTOR_SHIFT);
315 limits->max_sectors =
316 round_down(limits->max_sectors, size >> SECTOR_SHIFT);
317}
318EXPORT_SYMBOL(blk_queue_logical_block_size);
319
320/**
321 * blk_queue_physical_block_size - set physical block size for the queue
322 * @q: the request queue for the device
323 * @size: the physical block size, in bytes
324 *
325 * Description:
326 * This should be set to the lowest possible sector size that the
327 * hardware can operate on without reverting to read-modify-write
328 * operations.
329 */
330void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
331{
332 q->limits.physical_block_size = size;
333
334 if (q->limits.physical_block_size < q->limits.logical_block_size)
335 q->limits.physical_block_size = q->limits.logical_block_size;
336
337 if (q->limits.io_min < q->limits.physical_block_size)
338 q->limits.io_min = q->limits.physical_block_size;
339}
340EXPORT_SYMBOL(blk_queue_physical_block_size);
341
342/**
343 * blk_queue_zone_write_granularity - set zone write granularity for the queue
344 * @q: the request queue for the zoned device
345 * @size: the zone write granularity size, in bytes
346 *
347 * Description:
348 * This should be set to the lowest possible size allowing to write in
349 * sequential zones of a zoned block device.
350 */
351void blk_queue_zone_write_granularity(struct request_queue *q,
352 unsigned int size)
353{
354 if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
355 return;
356
357 q->limits.zone_write_granularity = size;
358
359 if (q->limits.zone_write_granularity < q->limits.logical_block_size)
360 q->limits.zone_write_granularity = q->limits.logical_block_size;
361}
362EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity);
363
364/**
365 * blk_queue_alignment_offset - set physical block alignment offset
366 * @q: the request queue for the device
367 * @offset: alignment offset in bytes
368 *
369 * Description:
370 * Some devices are naturally misaligned to compensate for things like
371 * the legacy DOS partition table 63-sector offset. Low-level drivers
372 * should call this function for devices whose first sector is not
373 * naturally aligned.
374 */
375void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
376{
377 q->limits.alignment_offset =
378 offset & (q->limits.physical_block_size - 1);
379 q->limits.misaligned = 0;
380}
381EXPORT_SYMBOL(blk_queue_alignment_offset);
382
383void blk_queue_update_readahead(struct request_queue *q)
384{
385 /*
386 * For read-ahead of large files to be effective, we need to read ahead
387 * at least twice the optimal I/O size.
388 */
389 q->backing_dev_info->ra_pages =
390 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
391 q->backing_dev_info->io_pages =
392 queue_max_sectors(q) >> (PAGE_SHIFT - 9);
393}
394EXPORT_SYMBOL_GPL(blk_queue_update_readahead);
395
396/**
397 * blk_limits_io_min - set minimum request size for a device
398 * @limits: the queue limits
399 * @min: smallest I/O size in bytes
400 *
401 * Description:
402 * Some devices have an internal block size bigger than the reported
403 * hardware sector size. This function can be used to signal the
404 * smallest I/O the device can perform without incurring a performance
405 * penalty.
406 */
407void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
408{
409 limits->io_min = min;
410
411 if (limits->io_min < limits->logical_block_size)
412 limits->io_min = limits->logical_block_size;
413
414 if (limits->io_min < limits->physical_block_size)
415 limits->io_min = limits->physical_block_size;
416}
417EXPORT_SYMBOL(blk_limits_io_min);
418
419/**
420 * blk_queue_io_min - set minimum request size for the queue
421 * @q: the request queue for the device
422 * @min: smallest I/O size in bytes
423 *
424 * Description:
425 * Storage devices may report a granularity or preferred minimum I/O
426 * size which is the smallest request the device can perform without
427 * incurring a performance penalty. For disk drives this is often the
428 * physical block size. For RAID arrays it is often the stripe chunk
429 * size. A properly aligned multiple of minimum_io_size is the
430 * preferred request size for workloads where a high number of I/O
431 * operations is desired.
432 */
433void blk_queue_io_min(struct request_queue *q, unsigned int min)
434{
435 blk_limits_io_min(&q->limits, min);
436}
437EXPORT_SYMBOL(blk_queue_io_min);
438
439/**
440 * blk_limits_io_opt - set optimal request size for a device
441 * @limits: the queue limits
442 * @opt: smallest I/O size in bytes
443 *
444 * Description:
445 * Storage devices may report an optimal I/O size, which is the
446 * device's preferred unit for sustained I/O. This is rarely reported
447 * for disk drives. For RAID arrays it is usually the stripe width or
448 * the internal track size. A properly aligned multiple of
449 * optimal_io_size is the preferred request size for workloads where
450 * sustained throughput is desired.
451 */
452void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
453{
454 limits->io_opt = opt;
455}
456EXPORT_SYMBOL(blk_limits_io_opt);
457
458/**
459 * blk_queue_io_opt - set optimal request size for the queue
460 * @q: the request queue for the device
461 * @opt: optimal request size in bytes
462 *
463 * Description:
464 * Storage devices may report an optimal I/O size, which is the
465 * device's preferred unit for sustained I/O. This is rarely reported
466 * for disk drives. For RAID arrays it is usually the stripe width or
467 * the internal track size. A properly aligned multiple of
468 * optimal_io_size is the preferred request size for workloads where
469 * sustained throughput is desired.
470 */
471void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
472{
473 blk_limits_io_opt(&q->limits, opt);
474 q->backing_dev_info->ra_pages =
475 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
476}
477EXPORT_SYMBOL(blk_queue_io_opt);
478
479static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
480{
481 sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
482 if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
483 sectors = PAGE_SIZE >> SECTOR_SHIFT;
484 return sectors;
485}
486
487/**
488 * blk_stack_limits - adjust queue_limits for stacked devices
489 * @t: the stacking driver limits (top device)
490 * @b: the underlying queue limits (bottom, component device)
491 * @start: first data sector within component device
492 *
493 * Description:
494 * This function is used by stacking drivers like MD and DM to ensure
495 * that all component devices have compatible block sizes and
496 * alignments. The stacking driver must provide a queue_limits
497 * struct (top) and then iteratively call the stacking function for
498 * all component (bottom) devices. The stacking function will
499 * attempt to combine the values and ensure proper alignment.
500 *
501 * Returns 0 if the top and bottom queue_limits are compatible. The
502 * top device's block sizes and alignment offsets may be adjusted to
503 * ensure alignment with the bottom device. If no compatible sizes
504 * and alignments exist, -1 is returned and the resulting top
505 * queue_limits will have the misaligned flag set to indicate that
506 * the alignment_offset is undefined.
507 */
508int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
509 sector_t start)
510{
511 unsigned int top, bottom, alignment, ret = 0;
512
513 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
514 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
515 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
516 t->max_write_same_sectors = min(t->max_write_same_sectors,
517 b->max_write_same_sectors);
518 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
519 b->max_write_zeroes_sectors);
520 t->max_zone_append_sectors = min(t->max_zone_append_sectors,
521 b->max_zone_append_sectors);
522 t->bounce = max(t->bounce, b->bounce);
523
524 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
525 b->seg_boundary_mask);
526 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
527 b->virt_boundary_mask);
528
529 t->max_segments = min_not_zero(t->max_segments, b->max_segments);
530 t->max_discard_segments = min_not_zero(t->max_discard_segments,
531 b->max_discard_segments);
532 t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
533 b->max_integrity_segments);
534
535 t->max_segment_size = min_not_zero(t->max_segment_size,
536 b->max_segment_size);
537
538 t->misaligned |= b->misaligned;
539
540 alignment = queue_limit_alignment_offset(b, start);
541
542 /* Bottom device has different alignment. Check that it is
543 * compatible with the current top alignment.
544 */
545 if (t->alignment_offset != alignment) {
546
547 top = max(t->physical_block_size, t->io_min)
548 + t->alignment_offset;
549 bottom = max(b->physical_block_size, b->io_min) + alignment;
550
551 /* Verify that top and bottom intervals line up */
552 if (max(top, bottom) % min(top, bottom)) {
553 t->misaligned = 1;
554 ret = -1;
555 }
556 }
557
558 t->logical_block_size = max(t->logical_block_size,
559 b->logical_block_size);
560
561 t->physical_block_size = max(t->physical_block_size,
562 b->physical_block_size);
563
564 t->io_min = max(t->io_min, b->io_min);
565 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
566
567 /* Set non-power-of-2 compatible chunk_sectors boundary */
568 if (b->chunk_sectors)
569 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
570
571 /* Physical block size a multiple of the logical block size? */
572 if (t->physical_block_size & (t->logical_block_size - 1)) {
573 t->physical_block_size = t->logical_block_size;
574 t->misaligned = 1;
575 ret = -1;
576 }
577
578 /* Minimum I/O a multiple of the physical block size? */
579 if (t->io_min & (t->physical_block_size - 1)) {
580 t->io_min = t->physical_block_size;
581 t->misaligned = 1;
582 ret = -1;
583 }
584
585 /* Optimal I/O a multiple of the physical block size? */
586 if (t->io_opt & (t->physical_block_size - 1)) {
587 t->io_opt = 0;
588 t->misaligned = 1;
589 ret = -1;
590 }
591
592 /* chunk_sectors a multiple of the physical block size? */
593 if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
594 t->chunk_sectors = 0;
595 t->misaligned = 1;
596 ret = -1;
597 }
598
599 t->raid_partial_stripes_expensive =
600 max(t->raid_partial_stripes_expensive,
601 b->raid_partial_stripes_expensive);
602
603 /* Find lowest common alignment_offset */
604 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
605 % max(t->physical_block_size, t->io_min);
606
607 /* Verify that new alignment_offset is on a logical block boundary */
608 if (t->alignment_offset & (t->logical_block_size - 1)) {
609 t->misaligned = 1;
610 ret = -1;
611 }
612
613 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
614 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
615 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
616
617 /* Discard alignment and granularity */
618 if (b->discard_granularity) {
619 alignment = queue_limit_discard_alignment(b, start);
620
621 if (t->discard_granularity != 0 &&
622 t->discard_alignment != alignment) {
623 top = t->discard_granularity + t->discard_alignment;
624 bottom = b->discard_granularity + alignment;
625
626 /* Verify that top and bottom intervals line up */
627 if ((max(top, bottom) % min(top, bottom)) != 0)
628 t->discard_misaligned = 1;
629 }
630
631 t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
632 b->max_discard_sectors);
633 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
634 b->max_hw_discard_sectors);
635 t->discard_granularity = max(t->discard_granularity,
636 b->discard_granularity);
637 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
638 t->discard_granularity;
639 }
640
641 t->zone_write_granularity = max(t->zone_write_granularity,
642 b->zone_write_granularity);
643 t->zoned = max(t->zoned, b->zoned);
644 return ret;
645}
646EXPORT_SYMBOL(blk_stack_limits);
647
648/**
649 * disk_stack_limits - adjust queue limits for stacked drivers
650 * @disk: MD/DM gendisk (top)
651 * @bdev: the underlying block device (bottom)
652 * @offset: offset to beginning of data within component device
653 *
654 * Description:
655 * Merges the limits for a top level gendisk and a bottom level
656 * block_device.
657 */
658void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
659 sector_t offset)
660{
661 struct request_queue *t = disk->queue;
662
663 if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
664 get_start_sect(bdev) + (offset >> 9)) < 0) {
665 char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE];
666
667 disk_name(disk, 0, top);
668 bdevname(bdev, bottom);
669
670 printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
671 top, bottom);
672 }
673
674 blk_queue_update_readahead(disk->queue);
675}
676EXPORT_SYMBOL(disk_stack_limits);
677
678/**
679 * blk_queue_update_dma_pad - update pad mask
680 * @q: the request queue for the device
681 * @mask: pad mask
682 *
683 * Update dma pad mask.
684 *
685 * Appending pad buffer to a request modifies the last entry of a
686 * scatter list such that it includes the pad buffer.
687 **/
688void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
689{
690 if (mask > q->dma_pad_mask)
691 q->dma_pad_mask = mask;
692}
693EXPORT_SYMBOL(blk_queue_update_dma_pad);
694
695/**
696 * blk_queue_segment_boundary - set boundary rules for segment merging
697 * @q: the request queue for the device
698 * @mask: the memory boundary mask
699 **/
700void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
701{
702 if (mask < PAGE_SIZE - 1) {
703 mask = PAGE_SIZE - 1;
704 printk(KERN_INFO "%s: set to minimum %lx\n",
705 __func__, mask);
706 }
707
708 q->limits.seg_boundary_mask = mask;
709}
710EXPORT_SYMBOL(blk_queue_segment_boundary);
711
712/**
713 * blk_queue_virt_boundary - set boundary rules for bio merging
714 * @q: the request queue for the device
715 * @mask: the memory boundary mask
716 **/
717void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
718{
719 q->limits.virt_boundary_mask = mask;
720
721 /*
722 * Devices that require a virtual boundary do not support scatter/gather
723 * I/O natively, but instead require a descriptor list entry for each
724 * page (which might not be idential to the Linux PAGE_SIZE). Because
725 * of that they are not limited by our notion of "segment size".
726 */
727 if (mask)
728 q->limits.max_segment_size = UINT_MAX;
729}
730EXPORT_SYMBOL(blk_queue_virt_boundary);
731
732/**
733 * blk_queue_dma_alignment - set dma length and memory alignment
734 * @q: the request queue for the device
735 * @mask: alignment mask
736 *
737 * description:
738 * set required memory and length alignment for direct dma transactions.
739 * this is used when building direct io requests for the queue.
740 *
741 **/
742void blk_queue_dma_alignment(struct request_queue *q, int mask)
743{
744 q->dma_alignment = mask;
745}
746EXPORT_SYMBOL(blk_queue_dma_alignment);
747
748/**
749 * blk_queue_update_dma_alignment - update dma length and memory alignment
750 * @q: the request queue for the device
751 * @mask: alignment mask
752 *
753 * description:
754 * update required memory and length alignment for direct dma transactions.
755 * If the requested alignment is larger than the current alignment, then
756 * the current queue alignment is updated to the new value, otherwise it
757 * is left alone. The design of this is to allow multiple objects
758 * (driver, device, transport etc) to set their respective
759 * alignments without having them interfere.
760 *
761 **/
762void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
763{
764 BUG_ON(mask > PAGE_SIZE);
765
766 if (mask > q->dma_alignment)
767 q->dma_alignment = mask;
768}
769EXPORT_SYMBOL(blk_queue_update_dma_alignment);
770
771/**
772 * blk_set_queue_depth - tell the block layer about the device queue depth
773 * @q: the request queue for the device
774 * @depth: queue depth
775 *
776 */
777void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
778{
779 q->queue_depth = depth;
780 rq_qos_queue_depth_changed(q);
781}
782EXPORT_SYMBOL(blk_set_queue_depth);
783
784/**
785 * blk_queue_write_cache - configure queue's write cache
786 * @q: the request queue for the device
787 * @wc: write back cache on or off
788 * @fua: device supports FUA writes, if true
789 *
790 * Tell the block layer about the write cache of @q.
791 */
792void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
793{
794 if (wc)
795 blk_queue_flag_set(QUEUE_FLAG_WC, q);
796 else
797 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
798 if (fua)
799 blk_queue_flag_set(QUEUE_FLAG_FUA, q);
800 else
801 blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
802
803 wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
804}
805EXPORT_SYMBOL_GPL(blk_queue_write_cache);
806
807/**
808 * blk_queue_required_elevator_features - Set a queue required elevator features
809 * @q: the request queue for the target device
810 * @features: Required elevator features OR'ed together
811 *
812 * Tell the block layer that for the device controlled through @q, only the
813 * only elevators that can be used are those that implement at least the set of
814 * features specified by @features.
815 */
816void blk_queue_required_elevator_features(struct request_queue *q,
817 unsigned int features)
818{
819 q->required_elevator_features = features;
820}
821EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features);
822
823/**
824 * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
825 * @q: the request queue for the device
826 * @dev: the device pointer for dma
827 *
828 * Tell the block layer about merging the segments by dma map of @q.
829 */
830bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
831 struct device *dev)
832{
833 unsigned long boundary = dma_get_merge_boundary(dev);
834
835 if (!boundary)
836 return false;
837
838 /* No need to update max_segment_size. see blk_queue_virt_boundary() */
839 blk_queue_virt_boundary(q, boundary);
840
841 return true;
842}
843EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
844
845/**
846 * blk_queue_set_zoned - configure a disk queue zoned model.
847 * @disk: the gendisk of the queue to configure
848 * @model: the zoned model to set
849 *
850 * Set the zoned model of the request queue of @disk according to @model.
851 * When @model is BLK_ZONED_HM (host managed), this should be called only
852 * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option).
853 * If @model specifies BLK_ZONED_HA (host aware), the effective model used
854 * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions
855 * on the disk.
856 */
857void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
858{
859 struct request_queue *q = disk->queue;
860
861 switch (model) {
862 case BLK_ZONED_HM:
863 /*
864 * Host managed devices are supported only if
865 * CONFIG_BLK_DEV_ZONED is enabled.
866 */
867 WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));
868 break;
869 case BLK_ZONED_HA:
870 /*
871 * Host aware devices can be treated either as regular block
872 * devices (similar to drive managed devices) or as zoned block
873 * devices to take advantage of the zone command set, similarly
874 * to host managed devices. We try the latter if there are no
875 * partitions and zoned block device support is enabled, else
876 * we do nothing special as far as the block layer is concerned.
877 */
878 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||
879 !xa_empty(&disk->part_tbl))
880 model = BLK_ZONED_NONE;
881 break;
882 case BLK_ZONED_NONE:
883 default:
884 if (WARN_ON_ONCE(model != BLK_ZONED_NONE))
885 model = BLK_ZONED_NONE;
886 break;
887 }
888
889 q->limits.zoned = model;
890 if (model != BLK_ZONED_NONE) {
891 /*
892 * Set the zone write granularity to the device logical block
893 * size by default. The driver can change this value if needed.
894 */
895 blk_queue_zone_write_granularity(q,
896 queue_logical_block_size(q));
897 } else {
898 blk_queue_clear_zone_settings(q);
899 }
900}
901EXPORT_SYMBOL_GPL(blk_queue_set_zoned);