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/gcd.h>
12 #include <linux/lcm.h>
13 #include <linux/jiffies.h>
14 #include <linux/gfp.h>
15 #include <linux/dma-mapping.h>
20 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
22 q->rq_timeout = timeout;
24 EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
27 * blk_set_default_limits - reset limits to default values
28 * @lim: the queue_limits structure to reset
31 * Returns a queue_limit struct to its default state.
33 void blk_set_default_limits(struct queue_limits *lim)
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;
57 lim->zoned = BLK_ZONED_NONE;
58 lim->zone_write_granularity = 0;
60 EXPORT_SYMBOL(blk_set_default_limits);
63 * blk_set_stacking_limits - set default limits for stacking devices
64 * @lim: the queue_limits structure to reset
67 * Returns a queue_limit struct to its default state. Should be used
68 * by stacking drivers like DM that have no internal limits.
70 void blk_set_stacking_limits(struct queue_limits *lim)
72 blk_set_default_limits(lim);
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;
85 EXPORT_SYMBOL(blk_set_stacking_limits);
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
93 * Force bouncing for ISA DMA ranges or highmem.
95 * DEPRECATED, don't use in new code.
97 void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce bounce)
99 q->limits.bounce = bounce;
101 EXPORT_SYMBOL(blk_queue_bounce_limit);
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
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
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.
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.
122 void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
124 struct queue_limits *limits = &q->limits;
125 unsigned int max_sectors;
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);
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);
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;
143 q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - 9);
145 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
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
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.
159 void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
161 q->limits.chunk_sectors = chunk_sectors;
163 EXPORT_SYMBOL(blk_queue_chunk_sectors);
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
170 void blk_queue_max_discard_sectors(struct request_queue *q,
171 unsigned int max_discard_sectors)
173 q->limits.max_hw_discard_sectors = max_discard_sectors;
174 q->limits.max_discard_sectors = max_discard_sectors;
176 EXPORT_SYMBOL(blk_queue_max_discard_sectors);
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
183 void blk_queue_max_write_same_sectors(struct request_queue *q,
184 unsigned int max_write_same_sectors)
186 q->limits.max_write_same_sectors = max_write_same_sectors;
188 EXPORT_SYMBOL(blk_queue_max_write_same_sectors);
191 * blk_queue_max_write_zeroes_sectors - set max sectors for a single
193 * @q: the request queue for the device
194 * @max_write_zeroes_sectors: maximum number of sectors to write per command
196 void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
197 unsigned int max_write_zeroes_sectors)
199 q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
201 EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors);
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
208 void blk_queue_max_zone_append_sectors(struct request_queue *q,
209 unsigned int max_zone_append_sectors)
211 unsigned int max_sectors;
213 if (WARN_ON(!blk_queue_is_zoned(q)))
216 max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors);
217 max_sectors = min(q->limits.chunk_sectors, max_sectors);
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.
224 WARN_ON(!max_sectors);
226 q->limits.max_zone_append_sectors = max_sectors;
228 EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors);
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
236 * Enables a low level driver to set an upper limit on the number of
237 * hw data segments in a request.
239 void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
243 printk(KERN_INFO "%s: set to minimum %d\n",
244 __func__, max_segments);
247 q->limits.max_segments = max_segments;
249 EXPORT_SYMBOL(blk_queue_max_segments);
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
257 * Enables a low level driver to set an upper limit on the number of
258 * segments in a discard request.
260 void blk_queue_max_discard_segments(struct request_queue *q,
261 unsigned short max_segments)
263 q->limits.max_discard_segments = max_segments;
265 EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
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
273 * Enables a low level driver to set an upper limit on the size of a
276 void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
278 if (max_size < PAGE_SIZE) {
279 max_size = PAGE_SIZE;
280 printk(KERN_INFO "%s: set to minimum %d\n",
284 /* see blk_queue_virt_boundary() for the explanation */
285 WARN_ON_ONCE(q->limits.virt_boundary_mask);
287 q->limits.max_segment_size = max_size;
289 EXPORT_SYMBOL(blk_queue_max_segment_size);
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
297 * This should be set to the lowest possible block size that the
298 * storage device can address. The default of 512 covers most
301 void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
303 struct queue_limits *limits = &q->limits;
305 limits->logical_block_size = size;
307 if (limits->physical_block_size < size)
308 limits->physical_block_size = size;
310 if (limits->io_min < limits->physical_block_size)
311 limits->io_min = limits->physical_block_size;
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);
318 EXPORT_SYMBOL(blk_queue_logical_block_size);
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
326 * This should be set to the lowest possible sector size that the
327 * hardware can operate on without reverting to read-modify-write
330 void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
332 q->limits.physical_block_size = size;
334 if (q->limits.physical_block_size < q->limits.logical_block_size)
335 q->limits.physical_block_size = q->limits.logical_block_size;
337 if (q->limits.io_min < q->limits.physical_block_size)
338 q->limits.io_min = q->limits.physical_block_size;
340 EXPORT_SYMBOL(blk_queue_physical_block_size);
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
348 * This should be set to the lowest possible size allowing to write in
349 * sequential zones of a zoned block device.
351 void blk_queue_zone_write_granularity(struct request_queue *q,
354 if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
357 q->limits.zone_write_granularity = size;
359 if (q->limits.zone_write_granularity < q->limits.logical_block_size)
360 q->limits.zone_write_granularity = q->limits.logical_block_size;
362 EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity);
365 * blk_queue_alignment_offset - set physical block alignment offset
366 * @q: the request queue for the device
367 * @offset: alignment offset in bytes
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
375 void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
377 q->limits.alignment_offset =
378 offset & (q->limits.physical_block_size - 1);
379 q->limits.misaligned = 0;
381 EXPORT_SYMBOL(blk_queue_alignment_offset);
383 void disk_update_readahead(struct gendisk *disk)
385 struct request_queue *q = disk->queue;
388 * For read-ahead of large files to be effective, we need to read ahead
389 * at least twice the optimal I/O size.
391 q->backing_dev_info->ra_pages =
392 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
393 q->backing_dev_info->io_pages =
394 queue_max_sectors(q) >> (PAGE_SHIFT - 9);
396 EXPORT_SYMBOL_GPL(disk_update_readahead);
399 * blk_limits_io_min - set minimum request size for a device
400 * @limits: the queue limits
401 * @min: smallest I/O size in bytes
404 * Some devices have an internal block size bigger than the reported
405 * hardware sector size. This function can be used to signal the
406 * smallest I/O the device can perform without incurring a performance
409 void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
411 limits->io_min = min;
413 if (limits->io_min < limits->logical_block_size)
414 limits->io_min = limits->logical_block_size;
416 if (limits->io_min < limits->physical_block_size)
417 limits->io_min = limits->physical_block_size;
419 EXPORT_SYMBOL(blk_limits_io_min);
422 * blk_queue_io_min - set minimum request size for the queue
423 * @q: the request queue for the device
424 * @min: smallest I/O size in bytes
427 * Storage devices may report a granularity or preferred minimum I/O
428 * size which is the smallest request the device can perform without
429 * incurring a performance penalty. For disk drives this is often the
430 * physical block size. For RAID arrays it is often the stripe chunk
431 * size. A properly aligned multiple of minimum_io_size is the
432 * preferred request size for workloads where a high number of I/O
433 * operations is desired.
435 void blk_queue_io_min(struct request_queue *q, unsigned int min)
437 blk_limits_io_min(&q->limits, min);
439 EXPORT_SYMBOL(blk_queue_io_min);
442 * blk_limits_io_opt - set optimal request size for a device
443 * @limits: the queue limits
444 * @opt: smallest I/O size in bytes
447 * Storage devices may report an optimal I/O size, which is the
448 * device's preferred unit for sustained I/O. This is rarely reported
449 * for disk drives. For RAID arrays it is usually the stripe width or
450 * the internal track size. A properly aligned multiple of
451 * optimal_io_size is the preferred request size for workloads where
452 * sustained throughput is desired.
454 void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
456 limits->io_opt = opt;
458 EXPORT_SYMBOL(blk_limits_io_opt);
461 * blk_queue_io_opt - set optimal request size for the queue
462 * @q: the request queue for the device
463 * @opt: optimal request size in bytes
466 * Storage devices may report an optimal I/O size, which is the
467 * device's preferred unit for sustained I/O. This is rarely reported
468 * for disk drives. For RAID arrays it is usually the stripe width or
469 * the internal track size. A properly aligned multiple of
470 * optimal_io_size is the preferred request size for workloads where
471 * sustained throughput is desired.
473 void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
475 blk_limits_io_opt(&q->limits, opt);
476 q->backing_dev_info->ra_pages =
477 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
479 EXPORT_SYMBOL(blk_queue_io_opt);
481 static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
483 sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
484 if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
485 sectors = PAGE_SIZE >> SECTOR_SHIFT;
490 * blk_stack_limits - adjust queue_limits for stacked devices
491 * @t: the stacking driver limits (top device)
492 * @b: the underlying queue limits (bottom, component device)
493 * @start: first data sector within component device
496 * This function is used by stacking drivers like MD and DM to ensure
497 * that all component devices have compatible block sizes and
498 * alignments. The stacking driver must provide a queue_limits
499 * struct (top) and then iteratively call the stacking function for
500 * all component (bottom) devices. The stacking function will
501 * attempt to combine the values and ensure proper alignment.
503 * Returns 0 if the top and bottom queue_limits are compatible. The
504 * top device's block sizes and alignment offsets may be adjusted to
505 * ensure alignment with the bottom device. If no compatible sizes
506 * and alignments exist, -1 is returned and the resulting top
507 * queue_limits will have the misaligned flag set to indicate that
508 * the alignment_offset is undefined.
510 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
513 unsigned int top, bottom, alignment, ret = 0;
515 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
516 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
517 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
518 t->max_write_same_sectors = min(t->max_write_same_sectors,
519 b->max_write_same_sectors);
520 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
521 b->max_write_zeroes_sectors);
522 t->max_zone_append_sectors = min(t->max_zone_append_sectors,
523 b->max_zone_append_sectors);
524 t->bounce = max(t->bounce, b->bounce);
526 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
527 b->seg_boundary_mask);
528 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
529 b->virt_boundary_mask);
531 t->max_segments = min_not_zero(t->max_segments, b->max_segments);
532 t->max_discard_segments = min_not_zero(t->max_discard_segments,
533 b->max_discard_segments);
534 t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
535 b->max_integrity_segments);
537 t->max_segment_size = min_not_zero(t->max_segment_size,
538 b->max_segment_size);
540 t->misaligned |= b->misaligned;
542 alignment = queue_limit_alignment_offset(b, start);
544 /* Bottom device has different alignment. Check that it is
545 * compatible with the current top alignment.
547 if (t->alignment_offset != alignment) {
549 top = max(t->physical_block_size, t->io_min)
550 + t->alignment_offset;
551 bottom = max(b->physical_block_size, b->io_min) + alignment;
553 /* Verify that top and bottom intervals line up */
554 if (max(top, bottom) % min(top, bottom)) {
560 t->logical_block_size = max(t->logical_block_size,
561 b->logical_block_size);
563 t->physical_block_size = max(t->physical_block_size,
564 b->physical_block_size);
566 t->io_min = max(t->io_min, b->io_min);
567 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
569 /* Set non-power-of-2 compatible chunk_sectors boundary */
570 if (b->chunk_sectors)
571 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
573 /* Physical block size a multiple of the logical block size? */
574 if (t->physical_block_size & (t->logical_block_size - 1)) {
575 t->physical_block_size = t->logical_block_size;
580 /* Minimum I/O a multiple of the physical block size? */
581 if (t->io_min & (t->physical_block_size - 1)) {
582 t->io_min = t->physical_block_size;
587 /* Optimal I/O a multiple of the physical block size? */
588 if (t->io_opt & (t->physical_block_size - 1)) {
594 /* chunk_sectors a multiple of the physical block size? */
595 if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
596 t->chunk_sectors = 0;
601 t->raid_partial_stripes_expensive =
602 max(t->raid_partial_stripes_expensive,
603 b->raid_partial_stripes_expensive);
605 /* Find lowest common alignment_offset */
606 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
607 % max(t->physical_block_size, t->io_min);
609 /* Verify that new alignment_offset is on a logical block boundary */
610 if (t->alignment_offset & (t->logical_block_size - 1)) {
615 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
616 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
617 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
619 /* Discard alignment and granularity */
620 if (b->discard_granularity) {
621 alignment = queue_limit_discard_alignment(b, start);
623 if (t->discard_granularity != 0 &&
624 t->discard_alignment != alignment) {
625 top = t->discard_granularity + t->discard_alignment;
626 bottom = b->discard_granularity + alignment;
628 /* Verify that top and bottom intervals line up */
629 if ((max(top, bottom) % min(top, bottom)) != 0)
630 t->discard_misaligned = 1;
633 t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
634 b->max_discard_sectors);
635 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
636 b->max_hw_discard_sectors);
637 t->discard_granularity = max(t->discard_granularity,
638 b->discard_granularity);
639 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
640 t->discard_granularity;
643 t->zone_write_granularity = max(t->zone_write_granularity,
644 b->zone_write_granularity);
645 t->zoned = max(t->zoned, b->zoned);
648 EXPORT_SYMBOL(blk_stack_limits);
651 * disk_stack_limits - adjust queue limits for stacked drivers
652 * @disk: MD/DM gendisk (top)
653 * @bdev: the underlying block device (bottom)
654 * @offset: offset to beginning of data within component device
657 * Merges the limits for a top level gendisk and a bottom level
660 void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
663 struct request_queue *t = disk->queue;
665 if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
666 get_start_sect(bdev) + (offset >> 9)) < 0)
667 pr_notice("%s: Warning: Device %pg is misaligned\n",
668 disk->disk_name, bdev);
670 disk_update_readahead(disk);
672 EXPORT_SYMBOL(disk_stack_limits);
675 * blk_queue_update_dma_pad - update pad mask
676 * @q: the request queue for the device
679 * Update dma pad mask.
681 * Appending pad buffer to a request modifies the last entry of a
682 * scatter list such that it includes the pad buffer.
684 void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
686 if (mask > q->dma_pad_mask)
687 q->dma_pad_mask = mask;
689 EXPORT_SYMBOL(blk_queue_update_dma_pad);
692 * blk_queue_segment_boundary - set boundary rules for segment merging
693 * @q: the request queue for the device
694 * @mask: the memory boundary mask
696 void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
698 if (mask < PAGE_SIZE - 1) {
699 mask = PAGE_SIZE - 1;
700 printk(KERN_INFO "%s: set to minimum %lx\n",
704 q->limits.seg_boundary_mask = mask;
706 EXPORT_SYMBOL(blk_queue_segment_boundary);
709 * blk_queue_virt_boundary - set boundary rules for bio merging
710 * @q: the request queue for the device
711 * @mask: the memory boundary mask
713 void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
715 q->limits.virt_boundary_mask = mask;
718 * Devices that require a virtual boundary do not support scatter/gather
719 * I/O natively, but instead require a descriptor list entry for each
720 * page (which might not be idential to the Linux PAGE_SIZE). Because
721 * of that they are not limited by our notion of "segment size".
724 q->limits.max_segment_size = UINT_MAX;
726 EXPORT_SYMBOL(blk_queue_virt_boundary);
729 * blk_queue_dma_alignment - set dma length and memory alignment
730 * @q: the request queue for the device
731 * @mask: alignment mask
734 * set required memory and length alignment for direct dma transactions.
735 * this is used when building direct io requests for the queue.
738 void blk_queue_dma_alignment(struct request_queue *q, int mask)
740 q->dma_alignment = mask;
742 EXPORT_SYMBOL(blk_queue_dma_alignment);
745 * blk_queue_update_dma_alignment - update dma length and memory alignment
746 * @q: the request queue for the device
747 * @mask: alignment mask
750 * update required memory and length alignment for direct dma transactions.
751 * If the requested alignment is larger than the current alignment, then
752 * the current queue alignment is updated to the new value, otherwise it
753 * is left alone. The design of this is to allow multiple objects
754 * (driver, device, transport etc) to set their respective
755 * alignments without having them interfere.
758 void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
760 BUG_ON(mask > PAGE_SIZE);
762 if (mask > q->dma_alignment)
763 q->dma_alignment = mask;
765 EXPORT_SYMBOL(blk_queue_update_dma_alignment);
768 * blk_set_queue_depth - tell the block layer about the device queue depth
769 * @q: the request queue for the device
770 * @depth: queue depth
773 void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
775 q->queue_depth = depth;
776 rq_qos_queue_depth_changed(q);
778 EXPORT_SYMBOL(blk_set_queue_depth);
781 * blk_queue_write_cache - configure queue's write cache
782 * @q: the request queue for the device
783 * @wc: write back cache on or off
784 * @fua: device supports FUA writes, if true
786 * Tell the block layer about the write cache of @q.
788 void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
791 blk_queue_flag_set(QUEUE_FLAG_WC, q);
793 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
795 blk_queue_flag_set(QUEUE_FLAG_FUA, q);
797 blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
799 wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
801 EXPORT_SYMBOL_GPL(blk_queue_write_cache);
804 * blk_queue_required_elevator_features - Set a queue required elevator features
805 * @q: the request queue for the target device
806 * @features: Required elevator features OR'ed together
808 * Tell the block layer that for the device controlled through @q, only the
809 * only elevators that can be used are those that implement at least the set of
810 * features specified by @features.
812 void blk_queue_required_elevator_features(struct request_queue *q,
813 unsigned int features)
815 q->required_elevator_features = features;
817 EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features);
820 * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
821 * @q: the request queue for the device
822 * @dev: the device pointer for dma
824 * Tell the block layer about merging the segments by dma map of @q.
826 bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
829 unsigned long boundary = dma_get_merge_boundary(dev);
834 /* No need to update max_segment_size. see blk_queue_virt_boundary() */
835 blk_queue_virt_boundary(q, boundary);
839 EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
842 * blk_queue_set_zoned - configure a disk queue zoned model.
843 * @disk: the gendisk of the queue to configure
844 * @model: the zoned model to set
846 * Set the zoned model of the request queue of @disk according to @model.
847 * When @model is BLK_ZONED_HM (host managed), this should be called only
848 * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option).
849 * If @model specifies BLK_ZONED_HA (host aware), the effective model used
850 * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions
853 void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
855 struct request_queue *q = disk->queue;
860 * Host managed devices are supported only if
861 * CONFIG_BLK_DEV_ZONED is enabled.
863 WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));
867 * Host aware devices can be treated either as regular block
868 * devices (similar to drive managed devices) or as zoned block
869 * devices to take advantage of the zone command set, similarly
870 * to host managed devices. We try the latter if there are no
871 * partitions and zoned block device support is enabled, else
872 * we do nothing special as far as the block layer is concerned.
874 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||
875 !xa_empty(&disk->part_tbl))
876 model = BLK_ZONED_NONE;
880 if (WARN_ON_ONCE(model != BLK_ZONED_NONE))
881 model = BLK_ZONED_NONE;
885 q->limits.zoned = model;
886 if (model != BLK_ZONED_NONE) {
888 * Set the zone write granularity to the device logical block
889 * size by default. The driver can change this value if needed.
891 blk_queue_zone_write_granularity(q,
892 queue_logical_block_size(q));
894 blk_queue_clear_zone_settings(q);
897 EXPORT_SYMBOL_GPL(blk_queue_set_zoned);