1 // SPDX-License-Identifier: GPL-2.0
3 * Functions related to setting various queue properties from drivers
5 #include <linux/kernel.h>
6 #include <linux/module.h>
7 #include <linux/init.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>
19 #include "blk-rq-qos.h"
22 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
24 q->rq_timeout = timeout;
26 EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
29 * blk_set_default_limits - reset limits to default values
30 * @lim: the queue_limits structure to reset
33 * Returns a queue_limit struct to its default state.
35 void blk_set_default_limits(struct queue_limits *lim)
37 lim->max_segments = BLK_MAX_SEGMENTS;
38 lim->max_discard_segments = 1;
39 lim->max_integrity_segments = 0;
40 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
41 lim->virt_boundary_mask = 0;
42 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
43 lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
44 lim->max_user_sectors = lim->max_dev_sectors = 0;
45 lim->chunk_sectors = 0;
46 lim->max_write_zeroes_sectors = 0;
47 lim->max_zone_append_sectors = 0;
48 lim->max_discard_sectors = 0;
49 lim->max_hw_discard_sectors = 0;
50 lim->max_secure_erase_sectors = 0;
51 lim->discard_granularity = 512;
52 lim->discard_alignment = 0;
53 lim->discard_misaligned = 0;
54 lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
55 lim->bounce = BLK_BOUNCE_NONE;
56 lim->alignment_offset = 0;
60 lim->zone_write_granularity = 0;
61 lim->dma_alignment = 511;
65 * blk_set_stacking_limits - set default limits for stacking devices
66 * @lim: the queue_limits structure to reset
69 * Returns a queue_limit struct to its default state. Should be used
70 * by stacking drivers like DM that have no internal limits.
72 void blk_set_stacking_limits(struct queue_limits *lim)
74 blk_set_default_limits(lim);
76 /* Inherit limits from component devices */
77 lim->max_segments = USHRT_MAX;
78 lim->max_discard_segments = USHRT_MAX;
79 lim->max_hw_sectors = UINT_MAX;
80 lim->max_segment_size = UINT_MAX;
81 lim->max_sectors = UINT_MAX;
82 lim->max_dev_sectors = UINT_MAX;
83 lim->max_write_zeroes_sectors = UINT_MAX;
84 lim->max_zone_append_sectors = UINT_MAX;
86 EXPORT_SYMBOL(blk_set_stacking_limits);
89 * blk_queue_bounce_limit - set bounce buffer limit for queue
90 * @q: the request queue for the device
91 * @bounce: bounce limit to enforce
94 * Force bouncing for ISA DMA ranges or highmem.
96 * DEPRECATED, don't use in new code.
98 void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce bounce)
100 q->limits.bounce = bounce;
102 EXPORT_SYMBOL(blk_queue_bounce_limit);
105 * blk_queue_max_hw_sectors - set max sectors for a request for this queue
106 * @q: the request queue for the device
107 * @max_hw_sectors: max hardware sectors in the usual 512b unit
110 * Enables a low level driver to set a hard upper limit,
111 * max_hw_sectors, on the size of requests. max_hw_sectors is set by
112 * the device driver based upon the capabilities of the I/O
115 * max_dev_sectors is a hard limit imposed by the storage device for
116 * READ/WRITE requests. It is set by the disk driver.
118 * max_sectors is a soft limit imposed by the block layer for
119 * filesystem type requests. This value can be overridden on a
120 * per-device basis in /sys/block/<device>/queue/max_sectors_kb.
121 * The soft limit can not exceed max_hw_sectors.
123 void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
125 struct queue_limits *limits = &q->limits;
126 unsigned int max_sectors;
128 if ((max_hw_sectors << 9) < PAGE_SIZE) {
129 max_hw_sectors = 1 << (PAGE_SHIFT - 9);
130 pr_info("%s: set to minimum %u\n", __func__, max_hw_sectors);
133 max_hw_sectors = round_down(max_hw_sectors,
134 limits->logical_block_size >> SECTOR_SHIFT);
135 limits->max_hw_sectors = max_hw_sectors;
137 max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
139 if (limits->max_user_sectors)
140 max_sectors = min(max_sectors, limits->max_user_sectors);
142 max_sectors = min(max_sectors, BLK_DEF_MAX_SECTORS_CAP);
144 max_sectors = round_down(max_sectors,
145 limits->logical_block_size >> SECTOR_SHIFT);
146 limits->max_sectors = max_sectors;
150 q->disk->bdi->io_pages = max_sectors >> (PAGE_SHIFT - 9);
152 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
155 * blk_queue_chunk_sectors - set size of the chunk for this queue
156 * @q: the request queue for the device
157 * @chunk_sectors: chunk sectors in the usual 512b unit
160 * If a driver doesn't want IOs to cross a given chunk size, it can set
161 * this limit and prevent merging across chunks. Note that the block layer
162 * must accept a page worth of data at any offset. So if the crossing of
163 * chunks is a hard limitation in the driver, it must still be prepared
164 * to split single page bios.
166 void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
168 q->limits.chunk_sectors = chunk_sectors;
170 EXPORT_SYMBOL(blk_queue_chunk_sectors);
173 * blk_queue_max_discard_sectors - set max sectors for a single discard
174 * @q: the request queue for the device
175 * @max_discard_sectors: maximum number of sectors to discard
177 void blk_queue_max_discard_sectors(struct request_queue *q,
178 unsigned int max_discard_sectors)
180 q->limits.max_hw_discard_sectors = max_discard_sectors;
181 q->limits.max_discard_sectors = max_discard_sectors;
183 EXPORT_SYMBOL(blk_queue_max_discard_sectors);
186 * blk_queue_max_secure_erase_sectors - set max sectors for a secure erase
187 * @q: the request queue for the device
188 * @max_sectors: maximum number of sectors to secure_erase
190 void blk_queue_max_secure_erase_sectors(struct request_queue *q,
191 unsigned int max_sectors)
193 q->limits.max_secure_erase_sectors = max_sectors;
195 EXPORT_SYMBOL(blk_queue_max_secure_erase_sectors);
198 * blk_queue_max_write_zeroes_sectors - set max sectors for a single
200 * @q: the request queue for the device
201 * @max_write_zeroes_sectors: maximum number of sectors to write per command
203 void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
204 unsigned int max_write_zeroes_sectors)
206 q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
208 EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors);
211 * blk_queue_max_zone_append_sectors - set max sectors for a single zone append
212 * @q: the request queue for the device
213 * @max_zone_append_sectors: maximum number of sectors to write per command
215 void blk_queue_max_zone_append_sectors(struct request_queue *q,
216 unsigned int max_zone_append_sectors)
218 unsigned int max_sectors;
220 if (WARN_ON(!blk_queue_is_zoned(q)))
223 max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors);
224 max_sectors = min(q->limits.chunk_sectors, max_sectors);
227 * Signal eventual driver bugs resulting in the max_zone_append sectors limit
228 * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set,
229 * or the max_hw_sectors limit not set.
231 WARN_ON(!max_sectors);
233 q->limits.max_zone_append_sectors = max_sectors;
235 EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors);
238 * blk_queue_max_segments - set max hw segments for a request for this queue
239 * @q: the request queue for the device
240 * @max_segments: max number of segments
243 * Enables a low level driver to set an upper limit on the number of
244 * hw data segments in a request.
246 void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
250 pr_info("%s: set to minimum %u\n", __func__, max_segments);
253 q->limits.max_segments = max_segments;
255 EXPORT_SYMBOL(blk_queue_max_segments);
258 * blk_queue_max_discard_segments - set max segments for discard requests
259 * @q: the request queue for the device
260 * @max_segments: max number of segments
263 * Enables a low level driver to set an upper limit on the number of
264 * segments in a discard request.
266 void blk_queue_max_discard_segments(struct request_queue *q,
267 unsigned short max_segments)
269 q->limits.max_discard_segments = max_segments;
271 EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
274 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
275 * @q: the request queue for the device
276 * @max_size: max size of segment in bytes
279 * Enables a low level driver to set an upper limit on the size of a
282 void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
284 if (max_size < PAGE_SIZE) {
285 max_size = PAGE_SIZE;
286 pr_info("%s: set to minimum %u\n", __func__, max_size);
289 /* see blk_queue_virt_boundary() for the explanation */
290 WARN_ON_ONCE(q->limits.virt_boundary_mask);
292 q->limits.max_segment_size = max_size;
294 EXPORT_SYMBOL(blk_queue_max_segment_size);
297 * blk_queue_logical_block_size - set logical block size for the queue
298 * @q: the request queue for the device
299 * @size: the logical block size, in bytes
302 * This should be set to the lowest possible block size that the
303 * storage device can address. The default of 512 covers most
306 void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
308 struct queue_limits *limits = &q->limits;
310 limits->logical_block_size = size;
312 if (limits->discard_granularity < limits->logical_block_size)
313 limits->discard_granularity = limits->logical_block_size;
315 if (limits->physical_block_size < size)
316 limits->physical_block_size = size;
318 if (limits->io_min < limits->physical_block_size)
319 limits->io_min = limits->physical_block_size;
321 limits->max_hw_sectors =
322 round_down(limits->max_hw_sectors, size >> SECTOR_SHIFT);
323 limits->max_sectors =
324 round_down(limits->max_sectors, size >> SECTOR_SHIFT);
326 EXPORT_SYMBOL(blk_queue_logical_block_size);
329 * blk_queue_physical_block_size - set physical block size for the queue
330 * @q: the request queue for the device
331 * @size: the physical block size, in bytes
334 * This should be set to the lowest possible sector size that the
335 * hardware can operate on without reverting to read-modify-write
338 void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
340 q->limits.physical_block_size = size;
342 if (q->limits.physical_block_size < q->limits.logical_block_size)
343 q->limits.physical_block_size = q->limits.logical_block_size;
345 if (q->limits.discard_granularity < q->limits.physical_block_size)
346 q->limits.discard_granularity = q->limits.physical_block_size;
348 if (q->limits.io_min < q->limits.physical_block_size)
349 q->limits.io_min = q->limits.physical_block_size;
351 EXPORT_SYMBOL(blk_queue_physical_block_size);
354 * blk_queue_zone_write_granularity - set zone write granularity for the queue
355 * @q: the request queue for the zoned device
356 * @size: the zone write granularity size, in bytes
359 * This should be set to the lowest possible size allowing to write in
360 * sequential zones of a zoned block device.
362 void blk_queue_zone_write_granularity(struct request_queue *q,
365 if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
368 q->limits.zone_write_granularity = size;
370 if (q->limits.zone_write_granularity < q->limits.logical_block_size)
371 q->limits.zone_write_granularity = q->limits.logical_block_size;
373 EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity);
376 * blk_queue_alignment_offset - set physical block alignment offset
377 * @q: the request queue for the device
378 * @offset: alignment offset in bytes
381 * Some devices are naturally misaligned to compensate for things like
382 * the legacy DOS partition table 63-sector offset. Low-level drivers
383 * should call this function for devices whose first sector is not
386 void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
388 q->limits.alignment_offset =
389 offset & (q->limits.physical_block_size - 1);
390 q->limits.misaligned = 0;
392 EXPORT_SYMBOL(blk_queue_alignment_offset);
394 void disk_update_readahead(struct gendisk *disk)
396 struct request_queue *q = disk->queue;
399 * For read-ahead of large files to be effective, we need to read ahead
400 * at least twice the optimal I/O size.
402 disk->bdi->ra_pages =
403 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
404 disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9);
406 EXPORT_SYMBOL_GPL(disk_update_readahead);
409 * blk_limits_io_min - set minimum request size for a device
410 * @limits: the queue limits
411 * @min: smallest I/O size in bytes
414 * Some devices have an internal block size bigger than the reported
415 * hardware sector size. This function can be used to signal the
416 * smallest I/O the device can perform without incurring a performance
419 void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
421 limits->io_min = min;
423 if (limits->io_min < limits->logical_block_size)
424 limits->io_min = limits->logical_block_size;
426 if (limits->io_min < limits->physical_block_size)
427 limits->io_min = limits->physical_block_size;
429 EXPORT_SYMBOL(blk_limits_io_min);
432 * blk_queue_io_min - set minimum request size for the queue
433 * @q: the request queue for the device
434 * @min: smallest I/O size in bytes
437 * Storage devices may report a granularity or preferred minimum I/O
438 * size which is the smallest request the device can perform without
439 * incurring a performance penalty. For disk drives this is often the
440 * physical block size. For RAID arrays it is often the stripe chunk
441 * size. A properly aligned multiple of minimum_io_size is the
442 * preferred request size for workloads where a high number of I/O
443 * operations is desired.
445 void blk_queue_io_min(struct request_queue *q, unsigned int min)
447 blk_limits_io_min(&q->limits, min);
449 EXPORT_SYMBOL(blk_queue_io_min);
452 * blk_limits_io_opt - set optimal request size for a device
453 * @limits: the queue limits
454 * @opt: smallest I/O size in bytes
457 * Storage devices may report an optimal I/O size, which is the
458 * device's preferred unit for sustained I/O. This is rarely reported
459 * for disk drives. For RAID arrays it is usually the stripe width or
460 * the internal track size. A properly aligned multiple of
461 * optimal_io_size is the preferred request size for workloads where
462 * sustained throughput is desired.
464 void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
466 limits->io_opt = opt;
468 EXPORT_SYMBOL(blk_limits_io_opt);
471 * blk_queue_io_opt - set optimal request size for the queue
472 * @q: the request queue for the device
473 * @opt: optimal request size in bytes
476 * Storage devices may report an optimal I/O size, which is the
477 * device's preferred unit for sustained I/O. This is rarely reported
478 * for disk drives. For RAID arrays it is usually the stripe width or
479 * the internal track size. A properly aligned multiple of
480 * optimal_io_size is the preferred request size for workloads where
481 * sustained throughput is desired.
483 void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
485 blk_limits_io_opt(&q->limits, opt);
488 q->disk->bdi->ra_pages =
489 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
491 EXPORT_SYMBOL(blk_queue_io_opt);
493 static int queue_limit_alignment_offset(const struct queue_limits *lim,
496 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
497 unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
500 return (granularity + lim->alignment_offset - alignment) % granularity;
503 static unsigned int queue_limit_discard_alignment(
504 const struct queue_limits *lim, sector_t sector)
506 unsigned int alignment, granularity, offset;
508 if (!lim->max_discard_sectors)
511 /* Why are these in bytes, not sectors? */
512 alignment = lim->discard_alignment >> SECTOR_SHIFT;
513 granularity = lim->discard_granularity >> SECTOR_SHIFT;
517 /* Offset of the partition start in 'granularity' sectors */
518 offset = sector_div(sector, granularity);
520 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
521 offset = (granularity + alignment - offset) % granularity;
523 /* Turn it back into bytes, gaah */
524 return offset << SECTOR_SHIFT;
527 static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
529 sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
530 if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
531 sectors = PAGE_SIZE >> SECTOR_SHIFT;
536 * blk_stack_limits - adjust queue_limits for stacked devices
537 * @t: the stacking driver limits (top device)
538 * @b: the underlying queue limits (bottom, component device)
539 * @start: first data sector within component device
542 * This function is used by stacking drivers like MD and DM to ensure
543 * that all component devices have compatible block sizes and
544 * alignments. The stacking driver must provide a queue_limits
545 * struct (top) and then iteratively call the stacking function for
546 * all component (bottom) devices. The stacking function will
547 * attempt to combine the values and ensure proper alignment.
549 * Returns 0 if the top and bottom queue_limits are compatible. The
550 * top device's block sizes and alignment offsets may be adjusted to
551 * ensure alignment with the bottom device. If no compatible sizes
552 * and alignments exist, -1 is returned and the resulting top
553 * queue_limits will have the misaligned flag set to indicate that
554 * the alignment_offset is undefined.
556 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
559 unsigned int top, bottom, alignment, ret = 0;
561 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
562 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
563 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
564 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
565 b->max_write_zeroes_sectors);
566 t->max_zone_append_sectors = min(t->max_zone_append_sectors,
567 b->max_zone_append_sectors);
568 t->bounce = max(t->bounce, b->bounce);
570 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
571 b->seg_boundary_mask);
572 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
573 b->virt_boundary_mask);
575 t->max_segments = min_not_zero(t->max_segments, b->max_segments);
576 t->max_discard_segments = min_not_zero(t->max_discard_segments,
577 b->max_discard_segments);
578 t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
579 b->max_integrity_segments);
581 t->max_segment_size = min_not_zero(t->max_segment_size,
582 b->max_segment_size);
584 t->misaligned |= b->misaligned;
586 alignment = queue_limit_alignment_offset(b, start);
588 /* Bottom device has different alignment. Check that it is
589 * compatible with the current top alignment.
591 if (t->alignment_offset != alignment) {
593 top = max(t->physical_block_size, t->io_min)
594 + t->alignment_offset;
595 bottom = max(b->physical_block_size, b->io_min) + alignment;
597 /* Verify that top and bottom intervals line up */
598 if (max(top, bottom) % min(top, bottom)) {
604 t->logical_block_size = max(t->logical_block_size,
605 b->logical_block_size);
607 t->physical_block_size = max(t->physical_block_size,
608 b->physical_block_size);
610 t->io_min = max(t->io_min, b->io_min);
611 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
612 t->dma_alignment = max(t->dma_alignment, b->dma_alignment);
614 /* Set non-power-of-2 compatible chunk_sectors boundary */
615 if (b->chunk_sectors)
616 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
618 /* Physical block size a multiple of the logical block size? */
619 if (t->physical_block_size & (t->logical_block_size - 1)) {
620 t->physical_block_size = t->logical_block_size;
625 /* Minimum I/O a multiple of the physical block size? */
626 if (t->io_min & (t->physical_block_size - 1)) {
627 t->io_min = t->physical_block_size;
632 /* Optimal I/O a multiple of the physical block size? */
633 if (t->io_opt & (t->physical_block_size - 1)) {
639 /* chunk_sectors a multiple of the physical block size? */
640 if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
641 t->chunk_sectors = 0;
646 t->raid_partial_stripes_expensive =
647 max(t->raid_partial_stripes_expensive,
648 b->raid_partial_stripes_expensive);
650 /* Find lowest common alignment_offset */
651 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
652 % max(t->physical_block_size, t->io_min);
654 /* Verify that new alignment_offset is on a logical block boundary */
655 if (t->alignment_offset & (t->logical_block_size - 1)) {
660 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
661 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
662 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
664 /* Discard alignment and granularity */
665 if (b->discard_granularity) {
666 alignment = queue_limit_discard_alignment(b, start);
668 if (t->discard_granularity != 0 &&
669 t->discard_alignment != alignment) {
670 top = t->discard_granularity + t->discard_alignment;
671 bottom = b->discard_granularity + alignment;
673 /* Verify that top and bottom intervals line up */
674 if ((max(top, bottom) % min(top, bottom)) != 0)
675 t->discard_misaligned = 1;
678 t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
679 b->max_discard_sectors);
680 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
681 b->max_hw_discard_sectors);
682 t->discard_granularity = max(t->discard_granularity,
683 b->discard_granularity);
684 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
685 t->discard_granularity;
687 t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors,
688 b->max_secure_erase_sectors);
689 t->zone_write_granularity = max(t->zone_write_granularity,
690 b->zone_write_granularity);
691 t->zoned = max(t->zoned, b->zoned);
694 EXPORT_SYMBOL(blk_stack_limits);
697 * disk_stack_limits - adjust queue limits for stacked drivers
698 * @disk: MD/DM gendisk (top)
699 * @bdev: the underlying block device (bottom)
700 * @offset: offset to beginning of data within component device
703 * Merges the limits for a top level gendisk and a bottom level
706 void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
709 struct request_queue *t = disk->queue;
711 if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
712 get_start_sect(bdev) + (offset >> 9)) < 0)
713 pr_notice("%s: Warning: Device %pg is misaligned\n",
714 disk->disk_name, bdev);
716 disk_update_readahead(disk);
718 EXPORT_SYMBOL(disk_stack_limits);
721 * blk_queue_update_dma_pad - update pad mask
722 * @q: the request queue for the device
725 * Update dma pad mask.
727 * Appending pad buffer to a request modifies the last entry of a
728 * scatter list such that it includes the pad buffer.
730 void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
732 if (mask > q->dma_pad_mask)
733 q->dma_pad_mask = mask;
735 EXPORT_SYMBOL(blk_queue_update_dma_pad);
738 * blk_queue_segment_boundary - set boundary rules for segment merging
739 * @q: the request queue for the device
740 * @mask: the memory boundary mask
742 void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
744 if (mask < PAGE_SIZE - 1) {
745 mask = PAGE_SIZE - 1;
746 pr_info("%s: set to minimum %lx\n", __func__, mask);
749 q->limits.seg_boundary_mask = mask;
751 EXPORT_SYMBOL(blk_queue_segment_boundary);
754 * blk_queue_virt_boundary - set boundary rules for bio merging
755 * @q: the request queue for the device
756 * @mask: the memory boundary mask
758 void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
760 q->limits.virt_boundary_mask = mask;
763 * Devices that require a virtual boundary do not support scatter/gather
764 * I/O natively, but instead require a descriptor list entry for each
765 * page (which might not be idential to the Linux PAGE_SIZE). Because
766 * of that they are not limited by our notion of "segment size".
769 q->limits.max_segment_size = UINT_MAX;
771 EXPORT_SYMBOL(blk_queue_virt_boundary);
774 * blk_queue_dma_alignment - set dma length and memory alignment
775 * @q: the request queue for the device
776 * @mask: alignment mask
779 * set required memory and length alignment for direct dma transactions.
780 * this is used when building direct io requests for the queue.
783 void blk_queue_dma_alignment(struct request_queue *q, int mask)
785 q->limits.dma_alignment = mask;
787 EXPORT_SYMBOL(blk_queue_dma_alignment);
790 * blk_queue_update_dma_alignment - update dma length and memory alignment
791 * @q: the request queue for the device
792 * @mask: alignment mask
795 * update required memory and length alignment for direct dma transactions.
796 * If the requested alignment is larger than the current alignment, then
797 * the current queue alignment is updated to the new value, otherwise it
798 * is left alone. The design of this is to allow multiple objects
799 * (driver, device, transport etc) to set their respective
800 * alignments without having them interfere.
803 void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
805 BUG_ON(mask > PAGE_SIZE);
807 if (mask > q->limits.dma_alignment)
808 q->limits.dma_alignment = mask;
810 EXPORT_SYMBOL(blk_queue_update_dma_alignment);
813 * blk_set_queue_depth - tell the block layer about the device queue depth
814 * @q: the request queue for the device
815 * @depth: queue depth
818 void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
820 q->queue_depth = depth;
821 rq_qos_queue_depth_changed(q);
823 EXPORT_SYMBOL(blk_set_queue_depth);
826 * blk_queue_write_cache - configure queue's write cache
827 * @q: the request queue for the device
828 * @wc: write back cache on or off
829 * @fua: device supports FUA writes, if true
831 * Tell the block layer about the write cache of @q.
833 void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
836 blk_queue_flag_set(QUEUE_FLAG_HW_WC, q);
837 blk_queue_flag_set(QUEUE_FLAG_WC, q);
839 blk_queue_flag_clear(QUEUE_FLAG_HW_WC, q);
840 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
843 blk_queue_flag_set(QUEUE_FLAG_FUA, q);
845 blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
847 EXPORT_SYMBOL_GPL(blk_queue_write_cache);
850 * blk_queue_required_elevator_features - Set a queue required elevator features
851 * @q: the request queue for the target device
852 * @features: Required elevator features OR'ed together
854 * Tell the block layer that for the device controlled through @q, only the
855 * only elevators that can be used are those that implement at least the set of
856 * features specified by @features.
858 void blk_queue_required_elevator_features(struct request_queue *q,
859 unsigned int features)
861 q->required_elevator_features = features;
863 EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features);
866 * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
867 * @q: the request queue for the device
868 * @dev: the device pointer for dma
870 * Tell the block layer about merging the segments by dma map of @q.
872 bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
875 unsigned long boundary = dma_get_merge_boundary(dev);
880 /* No need to update max_segment_size. see blk_queue_virt_boundary() */
881 blk_queue_virt_boundary(q, boundary);
885 EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
888 * disk_set_zoned - inidicate a zoned device
889 * @disk: gendisk to configure
891 void disk_set_zoned(struct gendisk *disk)
893 struct request_queue *q = disk->queue;
895 WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));
898 * Set the zone write granularity to the device logical block
899 * size by default. The driver can change this value if needed.
901 q->limits.zoned = true;
902 blk_queue_zone_write_granularity(q, queue_logical_block_size(q));
904 EXPORT_SYMBOL_GPL(disk_set_zoned);
906 int bdev_alignment_offset(struct block_device *bdev)
908 struct request_queue *q = bdev_get_queue(bdev);
910 if (q->limits.misaligned)
912 if (bdev_is_partition(bdev))
913 return queue_limit_alignment_offset(&q->limits,
914 bdev->bd_start_sect);
915 return q->limits.alignment_offset;
917 EXPORT_SYMBOL_GPL(bdev_alignment_offset);
919 unsigned int bdev_discard_alignment(struct block_device *bdev)
921 struct request_queue *q = bdev_get_queue(bdev);
923 if (bdev_is_partition(bdev))
924 return queue_limit_discard_alignment(&q->limits,
925 bdev->bd_start_sect);
926 return q->limits.discard_alignment;
928 EXPORT_SYMBOL_GPL(bdev_discard_alignment);