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>
21 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
23 q->rq_timeout = timeout;
25 EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
28 * blk_set_default_limits - reset limits to default values
29 * @lim: the queue_limits structure to reset
32 * Returns a queue_limit struct to its default state.
34 void blk_set_default_limits(struct queue_limits *lim)
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;
58 lim->zoned = BLK_ZONED_NONE;
59 lim->zone_write_granularity = 0;
60 lim->dma_alignment = 511;
62 EXPORT_SYMBOL(blk_set_default_limits);
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 printk(KERN_INFO "%s: set to minimum %d\n",
131 __func__, max_hw_sectors);
134 max_hw_sectors = round_down(max_hw_sectors,
135 limits->logical_block_size >> SECTOR_SHIFT);
136 limits->max_hw_sectors = max_hw_sectors;
138 max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
139 max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
140 max_sectors = round_down(max_sectors,
141 limits->logical_block_size >> SECTOR_SHIFT);
142 limits->max_sectors = max_sectors;
146 q->disk->bdi->io_pages = max_sectors >> (PAGE_SHIFT - 9);
148 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
151 * blk_queue_chunk_sectors - set size of the chunk for this queue
152 * @q: the request queue for the device
153 * @chunk_sectors: chunk sectors in the usual 512b unit
156 * If a driver doesn't want IOs to cross a given chunk size, it can set
157 * this limit and prevent merging across chunks. Note that the block layer
158 * must accept a page worth of data at any offset. So if the crossing of
159 * chunks is a hard limitation in the driver, it must still be prepared
160 * to split single page bios.
162 void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
164 q->limits.chunk_sectors = chunk_sectors;
166 EXPORT_SYMBOL(blk_queue_chunk_sectors);
169 * blk_queue_max_discard_sectors - set max sectors for a single discard
170 * @q: the request queue for the device
171 * @max_discard_sectors: maximum number of sectors to discard
173 void blk_queue_max_discard_sectors(struct request_queue *q,
174 unsigned int max_discard_sectors)
176 q->limits.max_hw_discard_sectors = max_discard_sectors;
177 q->limits.max_discard_sectors = max_discard_sectors;
179 EXPORT_SYMBOL(blk_queue_max_discard_sectors);
182 * blk_queue_max_secure_erase_sectors - set max sectors for a secure erase
183 * @q: the request queue for the device
184 * @max_sectors: maximum number of sectors to secure_erase
186 void blk_queue_max_secure_erase_sectors(struct request_queue *q,
187 unsigned int max_sectors)
189 q->limits.max_secure_erase_sectors = max_sectors;
191 EXPORT_SYMBOL(blk_queue_max_secure_erase_sectors);
194 * blk_queue_max_write_zeroes_sectors - set max sectors for a single
196 * @q: the request queue for the device
197 * @max_write_zeroes_sectors: maximum number of sectors to write per command
199 void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
200 unsigned int max_write_zeroes_sectors)
202 q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
204 EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors);
207 * blk_queue_max_zone_append_sectors - set max sectors for a single zone append
208 * @q: the request queue for the device
209 * @max_zone_append_sectors: maximum number of sectors to write per command
211 void blk_queue_max_zone_append_sectors(struct request_queue *q,
212 unsigned int max_zone_append_sectors)
214 unsigned int max_sectors;
216 if (WARN_ON(!blk_queue_is_zoned(q)))
219 max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors);
220 max_sectors = min(q->limits.chunk_sectors, max_sectors);
223 * Signal eventual driver bugs resulting in the max_zone_append sectors limit
224 * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set,
225 * or the max_hw_sectors limit not set.
227 WARN_ON(!max_sectors);
229 q->limits.max_zone_append_sectors = max_sectors;
231 EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors);
234 * blk_queue_max_segments - set max hw segments for a request for this queue
235 * @q: the request queue for the device
236 * @max_segments: max number of segments
239 * Enables a low level driver to set an upper limit on the number of
240 * hw data segments in a request.
242 void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
246 printk(KERN_INFO "%s: set to minimum %d\n",
247 __func__, max_segments);
250 q->limits.max_segments = max_segments;
252 EXPORT_SYMBOL(blk_queue_max_segments);
255 * blk_queue_max_discard_segments - set max segments for discard requests
256 * @q: the request queue for the device
257 * @max_segments: max number of segments
260 * Enables a low level driver to set an upper limit on the number of
261 * segments in a discard request.
263 void blk_queue_max_discard_segments(struct request_queue *q,
264 unsigned short max_segments)
266 q->limits.max_discard_segments = max_segments;
268 EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
271 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
272 * @q: the request queue for the device
273 * @max_size: max size of segment in bytes
276 * Enables a low level driver to set an upper limit on the size of a
279 void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
281 if (max_size < PAGE_SIZE) {
282 max_size = PAGE_SIZE;
283 printk(KERN_INFO "%s: set to minimum %d\n",
287 /* see blk_queue_virt_boundary() for the explanation */
288 WARN_ON_ONCE(q->limits.virt_boundary_mask);
290 q->limits.max_segment_size = max_size;
292 EXPORT_SYMBOL(blk_queue_max_segment_size);
295 * blk_queue_logical_block_size - set logical block size for the queue
296 * @q: the request queue for the device
297 * @size: the logical block size, in bytes
300 * This should be set to the lowest possible block size that the
301 * storage device can address. The default of 512 covers most
304 void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
306 struct queue_limits *limits = &q->limits;
308 limits->logical_block_size = size;
310 if (limits->physical_block_size < size)
311 limits->physical_block_size = size;
313 if (limits->io_min < limits->physical_block_size)
314 limits->io_min = limits->physical_block_size;
316 limits->max_hw_sectors =
317 round_down(limits->max_hw_sectors, size >> SECTOR_SHIFT);
318 limits->max_sectors =
319 round_down(limits->max_sectors, size >> SECTOR_SHIFT);
321 EXPORT_SYMBOL(blk_queue_logical_block_size);
324 * blk_queue_physical_block_size - set physical block size for the queue
325 * @q: the request queue for the device
326 * @size: the physical block size, in bytes
329 * This should be set to the lowest possible sector size that the
330 * hardware can operate on without reverting to read-modify-write
333 void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
335 q->limits.physical_block_size = size;
337 if (q->limits.physical_block_size < q->limits.logical_block_size)
338 q->limits.physical_block_size = q->limits.logical_block_size;
340 if (q->limits.io_min < q->limits.physical_block_size)
341 q->limits.io_min = q->limits.physical_block_size;
343 EXPORT_SYMBOL(blk_queue_physical_block_size);
346 * blk_queue_zone_write_granularity - set zone write granularity for the queue
347 * @q: the request queue for the zoned device
348 * @size: the zone write granularity size, in bytes
351 * This should be set to the lowest possible size allowing to write in
352 * sequential zones of a zoned block device.
354 void blk_queue_zone_write_granularity(struct request_queue *q,
357 if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
360 q->limits.zone_write_granularity = size;
362 if (q->limits.zone_write_granularity < q->limits.logical_block_size)
363 q->limits.zone_write_granularity = q->limits.logical_block_size;
365 EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity);
368 * blk_queue_alignment_offset - set physical block alignment offset
369 * @q: the request queue for the device
370 * @offset: alignment offset in bytes
373 * Some devices are naturally misaligned to compensate for things like
374 * the legacy DOS partition table 63-sector offset. Low-level drivers
375 * should call this function for devices whose first sector is not
378 void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
380 q->limits.alignment_offset =
381 offset & (q->limits.physical_block_size - 1);
382 q->limits.misaligned = 0;
384 EXPORT_SYMBOL(blk_queue_alignment_offset);
386 void disk_update_readahead(struct gendisk *disk)
388 struct request_queue *q = disk->queue;
391 * For read-ahead of large files to be effective, we need to read ahead
392 * at least twice the optimal I/O size.
394 disk->bdi->ra_pages =
395 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
396 disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9);
398 EXPORT_SYMBOL_GPL(disk_update_readahead);
401 * blk_limits_io_min - set minimum request size for a device
402 * @limits: the queue limits
403 * @min: smallest I/O size in bytes
406 * Some devices have an internal block size bigger than the reported
407 * hardware sector size. This function can be used to signal the
408 * smallest I/O the device can perform without incurring a performance
411 void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
413 limits->io_min = min;
415 if (limits->io_min < limits->logical_block_size)
416 limits->io_min = limits->logical_block_size;
418 if (limits->io_min < limits->physical_block_size)
419 limits->io_min = limits->physical_block_size;
421 EXPORT_SYMBOL(blk_limits_io_min);
424 * blk_queue_io_min - set minimum request size for the queue
425 * @q: the request queue for the device
426 * @min: smallest I/O size in bytes
429 * Storage devices may report a granularity or preferred minimum I/O
430 * size which is the smallest request the device can perform without
431 * incurring a performance penalty. For disk drives this is often the
432 * physical block size. For RAID arrays it is often the stripe chunk
433 * size. A properly aligned multiple of minimum_io_size is the
434 * preferred request size for workloads where a high number of I/O
435 * operations is desired.
437 void blk_queue_io_min(struct request_queue *q, unsigned int min)
439 blk_limits_io_min(&q->limits, min);
441 EXPORT_SYMBOL(blk_queue_io_min);
444 * blk_limits_io_opt - set optimal request size for a device
445 * @limits: the queue limits
446 * @opt: smallest I/O size in bytes
449 * Storage devices may report an optimal I/O size, which is the
450 * device's preferred unit for sustained I/O. This is rarely reported
451 * for disk drives. For RAID arrays it is usually the stripe width or
452 * the internal track size. A properly aligned multiple of
453 * optimal_io_size is the preferred request size for workloads where
454 * sustained throughput is desired.
456 void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
458 limits->io_opt = opt;
460 EXPORT_SYMBOL(blk_limits_io_opt);
463 * blk_queue_io_opt - set optimal request size for the queue
464 * @q: the request queue for the device
465 * @opt: optimal request size in bytes
468 * Storage devices may report an optimal I/O size, which is the
469 * device's preferred unit for sustained I/O. This is rarely reported
470 * for disk drives. For RAID arrays it is usually the stripe width or
471 * the internal track size. A properly aligned multiple of
472 * optimal_io_size is the preferred request size for workloads where
473 * sustained throughput is desired.
475 void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
477 blk_limits_io_opt(&q->limits, opt);
480 q->disk->bdi->ra_pages =
481 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
483 EXPORT_SYMBOL(blk_queue_io_opt);
485 static int queue_limit_alignment_offset(struct queue_limits *lim,
488 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
489 unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
492 return (granularity + lim->alignment_offset - alignment) % granularity;
495 static unsigned int queue_limit_discard_alignment(struct queue_limits *lim,
498 unsigned int alignment, granularity, offset;
500 if (!lim->max_discard_sectors)
503 /* Why are these in bytes, not sectors? */
504 alignment = lim->discard_alignment >> SECTOR_SHIFT;
505 granularity = lim->discard_granularity >> SECTOR_SHIFT;
509 /* Offset of the partition start in 'granularity' sectors */
510 offset = sector_div(sector, granularity);
512 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
513 offset = (granularity + alignment - offset) % granularity;
515 /* Turn it back into bytes, gaah */
516 return offset << SECTOR_SHIFT;
519 static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
521 sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
522 if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
523 sectors = PAGE_SIZE >> SECTOR_SHIFT;
528 * blk_stack_limits - adjust queue_limits for stacked devices
529 * @t: the stacking driver limits (top device)
530 * @b: the underlying queue limits (bottom, component device)
531 * @start: first data sector within component device
534 * This function is used by stacking drivers like MD and DM to ensure
535 * that all component devices have compatible block sizes and
536 * alignments. The stacking driver must provide a queue_limits
537 * struct (top) and then iteratively call the stacking function for
538 * all component (bottom) devices. The stacking function will
539 * attempt to combine the values and ensure proper alignment.
541 * Returns 0 if the top and bottom queue_limits are compatible. The
542 * top device's block sizes and alignment offsets may be adjusted to
543 * ensure alignment with the bottom device. If no compatible sizes
544 * and alignments exist, -1 is returned and the resulting top
545 * queue_limits will have the misaligned flag set to indicate that
546 * the alignment_offset is undefined.
548 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
551 unsigned int top, bottom, alignment, ret = 0;
553 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
554 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
555 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
556 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
557 b->max_write_zeroes_sectors);
558 t->max_zone_append_sectors = min(t->max_zone_append_sectors,
559 b->max_zone_append_sectors);
560 t->bounce = max(t->bounce, b->bounce);
562 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
563 b->seg_boundary_mask);
564 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
565 b->virt_boundary_mask);
567 t->max_segments = min_not_zero(t->max_segments, b->max_segments);
568 t->max_discard_segments = min_not_zero(t->max_discard_segments,
569 b->max_discard_segments);
570 t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
571 b->max_integrity_segments);
573 t->max_segment_size = min_not_zero(t->max_segment_size,
574 b->max_segment_size);
576 t->misaligned |= b->misaligned;
578 alignment = queue_limit_alignment_offset(b, start);
580 /* Bottom device has different alignment. Check that it is
581 * compatible with the current top alignment.
583 if (t->alignment_offset != alignment) {
585 top = max(t->physical_block_size, t->io_min)
586 + t->alignment_offset;
587 bottom = max(b->physical_block_size, b->io_min) + alignment;
589 /* Verify that top and bottom intervals line up */
590 if (max(top, bottom) % min(top, bottom)) {
596 t->logical_block_size = max(t->logical_block_size,
597 b->logical_block_size);
599 t->physical_block_size = max(t->physical_block_size,
600 b->physical_block_size);
602 t->io_min = max(t->io_min, b->io_min);
603 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
604 t->dma_alignment = max(t->dma_alignment, b->dma_alignment);
606 /* Set non-power-of-2 compatible chunk_sectors boundary */
607 if (b->chunk_sectors)
608 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
610 /* Physical block size a multiple of the logical block size? */
611 if (t->physical_block_size & (t->logical_block_size - 1)) {
612 t->physical_block_size = t->logical_block_size;
617 /* Minimum I/O a multiple of the physical block size? */
618 if (t->io_min & (t->physical_block_size - 1)) {
619 t->io_min = t->physical_block_size;
624 /* Optimal I/O a multiple of the physical block size? */
625 if (t->io_opt & (t->physical_block_size - 1)) {
631 /* chunk_sectors a multiple of the physical block size? */
632 if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
633 t->chunk_sectors = 0;
638 t->raid_partial_stripes_expensive =
639 max(t->raid_partial_stripes_expensive,
640 b->raid_partial_stripes_expensive);
642 /* Find lowest common alignment_offset */
643 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
644 % max(t->physical_block_size, t->io_min);
646 /* Verify that new alignment_offset is on a logical block boundary */
647 if (t->alignment_offset & (t->logical_block_size - 1)) {
652 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
653 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
654 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
656 /* Discard alignment and granularity */
657 if (b->discard_granularity) {
658 alignment = queue_limit_discard_alignment(b, start);
660 if (t->discard_granularity != 0 &&
661 t->discard_alignment != alignment) {
662 top = t->discard_granularity + t->discard_alignment;
663 bottom = b->discard_granularity + alignment;
665 /* Verify that top and bottom intervals line up */
666 if ((max(top, bottom) % min(top, bottom)) != 0)
667 t->discard_misaligned = 1;
670 t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
671 b->max_discard_sectors);
672 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
673 b->max_hw_discard_sectors);
674 t->discard_granularity = max(t->discard_granularity,
675 b->discard_granularity);
676 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
677 t->discard_granularity;
679 t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors,
680 b->max_secure_erase_sectors);
681 t->zone_write_granularity = max(t->zone_write_granularity,
682 b->zone_write_granularity);
683 t->zoned = max(t->zoned, b->zoned);
686 EXPORT_SYMBOL(blk_stack_limits);
689 * disk_stack_limits - adjust queue limits for stacked drivers
690 * @disk: MD/DM gendisk (top)
691 * @bdev: the underlying block device (bottom)
692 * @offset: offset to beginning of data within component device
695 * Merges the limits for a top level gendisk and a bottom level
698 void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
701 struct request_queue *t = disk->queue;
703 if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
704 get_start_sect(bdev) + (offset >> 9)) < 0)
705 pr_notice("%s: Warning: Device %pg is misaligned\n",
706 disk->disk_name, bdev);
708 disk_update_readahead(disk);
710 EXPORT_SYMBOL(disk_stack_limits);
713 * blk_queue_update_dma_pad - update pad mask
714 * @q: the request queue for the device
717 * Update dma pad mask.
719 * Appending pad buffer to a request modifies the last entry of a
720 * scatter list such that it includes the pad buffer.
722 void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
724 if (mask > q->dma_pad_mask)
725 q->dma_pad_mask = mask;
727 EXPORT_SYMBOL(blk_queue_update_dma_pad);
730 * blk_queue_segment_boundary - set boundary rules for segment merging
731 * @q: the request queue for the device
732 * @mask: the memory boundary mask
734 void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
736 if (mask < PAGE_SIZE - 1) {
737 mask = PAGE_SIZE - 1;
738 printk(KERN_INFO "%s: set to minimum %lx\n",
742 q->limits.seg_boundary_mask = mask;
744 EXPORT_SYMBOL(blk_queue_segment_boundary);
747 * blk_queue_virt_boundary - set boundary rules for bio merging
748 * @q: the request queue for the device
749 * @mask: the memory boundary mask
751 void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
753 q->limits.virt_boundary_mask = mask;
756 * Devices that require a virtual boundary do not support scatter/gather
757 * I/O natively, but instead require a descriptor list entry for each
758 * page (which might not be idential to the Linux PAGE_SIZE). Because
759 * of that they are not limited by our notion of "segment size".
762 q->limits.max_segment_size = UINT_MAX;
764 EXPORT_SYMBOL(blk_queue_virt_boundary);
767 * blk_queue_dma_alignment - set dma length and memory alignment
768 * @q: the request queue for the device
769 * @mask: alignment mask
772 * set required memory and length alignment for direct dma transactions.
773 * this is used when building direct io requests for the queue.
776 void blk_queue_dma_alignment(struct request_queue *q, int mask)
778 q->limits.dma_alignment = mask;
780 EXPORT_SYMBOL(blk_queue_dma_alignment);
783 * blk_queue_update_dma_alignment - update dma length and memory alignment
784 * @q: the request queue for the device
785 * @mask: alignment mask
788 * update required memory and length alignment for direct dma transactions.
789 * If the requested alignment is larger than the current alignment, then
790 * the current queue alignment is updated to the new value, otherwise it
791 * is left alone. The design of this is to allow multiple objects
792 * (driver, device, transport etc) to set their respective
793 * alignments without having them interfere.
796 void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
798 BUG_ON(mask > PAGE_SIZE);
800 if (mask > q->limits.dma_alignment)
801 q->limits.dma_alignment = mask;
803 EXPORT_SYMBOL(blk_queue_update_dma_alignment);
806 * blk_set_queue_depth - tell the block layer about the device queue depth
807 * @q: the request queue for the device
808 * @depth: queue depth
811 void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
813 q->queue_depth = depth;
814 rq_qos_queue_depth_changed(q);
816 EXPORT_SYMBOL(blk_set_queue_depth);
819 * blk_queue_write_cache - configure queue's write cache
820 * @q: the request queue for the device
821 * @wc: write back cache on or off
822 * @fua: device supports FUA writes, if true
824 * Tell the block layer about the write cache of @q.
826 void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
829 blk_queue_flag_set(QUEUE_FLAG_WC, q);
831 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
833 blk_queue_flag_set(QUEUE_FLAG_FUA, q);
835 blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
837 wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
839 EXPORT_SYMBOL_GPL(blk_queue_write_cache);
842 * blk_queue_required_elevator_features - Set a queue required elevator features
843 * @q: the request queue for the target device
844 * @features: Required elevator features OR'ed together
846 * Tell the block layer that for the device controlled through @q, only the
847 * only elevators that can be used are those that implement at least the set of
848 * features specified by @features.
850 void blk_queue_required_elevator_features(struct request_queue *q,
851 unsigned int features)
853 q->required_elevator_features = features;
855 EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features);
858 * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
859 * @q: the request queue for the device
860 * @dev: the device pointer for dma
862 * Tell the block layer about merging the segments by dma map of @q.
864 bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
867 unsigned long boundary = dma_get_merge_boundary(dev);
872 /* No need to update max_segment_size. see blk_queue_virt_boundary() */
873 blk_queue_virt_boundary(q, boundary);
877 EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
879 static bool disk_has_partitions(struct gendisk *disk)
882 struct block_device *part;
886 xa_for_each(&disk->part_tbl, idx, part) {
887 if (bdev_is_partition(part)) {
898 * disk_set_zoned - configure the zoned model for a disk
899 * @disk: the gendisk of the queue to configure
900 * @model: the zoned model to set
902 * Set the zoned model of @disk to @model.
904 * When @model is BLK_ZONED_HM (host managed), this should be called only
905 * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option).
906 * If @model specifies BLK_ZONED_HA (host aware), the effective model used
907 * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions
910 void disk_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
912 struct request_queue *q = disk->queue;
917 * Host managed devices are supported only if
918 * CONFIG_BLK_DEV_ZONED is enabled.
920 WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));
924 * Host aware devices can be treated either as regular block
925 * devices (similar to drive managed devices) or as zoned block
926 * devices to take advantage of the zone command set, similarly
927 * to host managed devices. We try the latter if there are no
928 * partitions and zoned block device support is enabled, else
929 * we do nothing special as far as the block layer is concerned.
931 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||
932 disk_has_partitions(disk))
933 model = BLK_ZONED_NONE;
937 if (WARN_ON_ONCE(model != BLK_ZONED_NONE))
938 model = BLK_ZONED_NONE;
942 q->limits.zoned = model;
943 if (model != BLK_ZONED_NONE) {
945 * Set the zone write granularity to the device logical block
946 * size by default. The driver can change this value if needed.
948 blk_queue_zone_write_granularity(q,
949 queue_logical_block_size(q));
951 disk_clear_zone_settings(disk);
954 EXPORT_SYMBOL_GPL(disk_set_zoned);
956 int bdev_alignment_offset(struct block_device *bdev)
958 struct request_queue *q = bdev_get_queue(bdev);
960 if (q->limits.misaligned)
962 if (bdev_is_partition(bdev))
963 return queue_limit_alignment_offset(&q->limits,
964 bdev->bd_start_sect);
965 return q->limits.alignment_offset;
967 EXPORT_SYMBOL_GPL(bdev_alignment_offset);
969 unsigned int bdev_discard_alignment(struct block_device *bdev)
971 struct request_queue *q = bdev_get_queue(bdev);
973 if (bdev_is_partition(bdev))
974 return queue_limit_discard_alignment(&q->limits,
975 bdev->bd_start_sect);
976 return q->limits.discard_alignment;
978 EXPORT_SYMBOL_GPL(bdev_discard_alignment);