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_stacking_limits - set default limits for stacking devices
30 * @lim: the queue_limits structure to reset
32 * Prepare queue limits for applying limits from underlying devices using
35 void blk_set_stacking_limits(struct queue_limits
*lim
)
37 memset(lim
, 0, sizeof(*lim
));
38 lim
->logical_block_size
= SECTOR_SIZE
;
39 lim
->physical_block_size
= SECTOR_SIZE
;
40 lim
->io_min
= SECTOR_SIZE
;
41 lim
->discard_granularity
= SECTOR_SIZE
;
42 lim
->dma_alignment
= SECTOR_SIZE
- 1;
43 lim
->seg_boundary_mask
= BLK_SEG_BOUNDARY_MASK
;
45 /* Inherit limits from component devices */
46 lim
->max_segments
= USHRT_MAX
;
47 lim
->max_discard_segments
= USHRT_MAX
;
48 lim
->max_hw_sectors
= UINT_MAX
;
49 lim
->max_segment_size
= UINT_MAX
;
50 lim
->max_sectors
= UINT_MAX
;
51 lim
->max_dev_sectors
= UINT_MAX
;
52 lim
->max_write_zeroes_sectors
= UINT_MAX
;
53 lim
->max_zone_append_sectors
= UINT_MAX
;
54 lim
->max_user_discard_sectors
= UINT_MAX
;
56 EXPORT_SYMBOL(blk_set_stacking_limits
);
58 static void blk_apply_bdi_limits(struct backing_dev_info
*bdi
,
59 struct queue_limits
*lim
)
62 * For read-ahead of large files to be effective, we need to read ahead
63 * at least twice the optimal I/O size.
65 bdi
->ra_pages
= max(lim
->io_opt
* 2 / PAGE_SIZE
, VM_READAHEAD_PAGES
);
66 bdi
->io_pages
= lim
->max_sectors
>> PAGE_SECTORS_SHIFT
;
69 static int blk_validate_zoned_limits(struct queue_limits
*lim
)
72 if (WARN_ON_ONCE(lim
->max_open_zones
) ||
73 WARN_ON_ONCE(lim
->max_active_zones
) ||
74 WARN_ON_ONCE(lim
->zone_write_granularity
) ||
75 WARN_ON_ONCE(lim
->max_zone_append_sectors
))
80 if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED
)))
83 if (lim
->zone_write_granularity
< lim
->logical_block_size
)
84 lim
->zone_write_granularity
= lim
->logical_block_size
;
86 if (lim
->max_zone_append_sectors
) {
88 * The Zone Append size is limited by the maximum I/O size
89 * and the zone size given that it can't span zones.
91 lim
->max_zone_append_sectors
=
92 min3(lim
->max_hw_sectors
,
93 lim
->max_zone_append_sectors
,
101 * Check that the limits in lim are valid, initialize defaults for unset
102 * values, and cap values based on others where needed.
104 static int blk_validate_limits(struct queue_limits
*lim
)
106 unsigned int max_hw_sectors
;
109 * Unless otherwise specified, default to 512 byte logical blocks and a
110 * physical block size equal to the logical block size.
112 if (!lim
->logical_block_size
)
113 lim
->logical_block_size
= SECTOR_SIZE
;
114 if (lim
->physical_block_size
< lim
->logical_block_size
)
115 lim
->physical_block_size
= lim
->logical_block_size
;
118 * The minimum I/O size defaults to the physical block size unless
119 * explicitly overridden.
121 if (lim
->io_min
< lim
->physical_block_size
)
122 lim
->io_min
= lim
->physical_block_size
;
125 * max_hw_sectors has a somewhat weird default for historical reason,
126 * but driver really should set their own instead of relying on this
129 * The block layer relies on the fact that every driver can
130 * handle at lest a page worth of data per I/O, and needs the value
131 * aligned to the logical block size.
133 if (!lim
->max_hw_sectors
)
134 lim
->max_hw_sectors
= BLK_SAFE_MAX_SECTORS
;
135 if (WARN_ON_ONCE(lim
->max_hw_sectors
< PAGE_SECTORS
))
137 lim
->max_hw_sectors
= round_down(lim
->max_hw_sectors
,
138 lim
->logical_block_size
>> SECTOR_SHIFT
);
141 * The actual max_sectors value is a complex beast and also takes the
142 * max_dev_sectors value (set by SCSI ULPs) and a user configurable
143 * value into account. The ->max_sectors value is always calculated
144 * from these, so directly setting it won't have any effect.
146 max_hw_sectors
= min_not_zero(lim
->max_hw_sectors
,
147 lim
->max_dev_sectors
);
148 if (lim
->max_user_sectors
) {
149 if (lim
->max_user_sectors
< PAGE_SIZE
/ SECTOR_SIZE
)
151 lim
->max_sectors
= min(max_hw_sectors
, lim
->max_user_sectors
);
153 lim
->max_sectors
= min(max_hw_sectors
, BLK_DEF_MAX_SECTORS_CAP
);
155 lim
->max_sectors
= round_down(lim
->max_sectors
,
156 lim
->logical_block_size
>> SECTOR_SHIFT
);
159 * Random default for the maximum number of segments. Driver should not
160 * rely on this and set their own.
162 if (!lim
->max_segments
)
163 lim
->max_segments
= BLK_MAX_SEGMENTS
;
165 lim
->max_discard_sectors
=
166 min(lim
->max_hw_discard_sectors
, lim
->max_user_discard_sectors
);
168 if (!lim
->max_discard_segments
)
169 lim
->max_discard_segments
= 1;
171 if (lim
->discard_granularity
< lim
->physical_block_size
)
172 lim
->discard_granularity
= lim
->physical_block_size
;
175 * By default there is no limit on the segment boundary alignment,
176 * but if there is one it can't be smaller than the page size as
177 * that would break all the normal I/O patterns.
179 if (!lim
->seg_boundary_mask
)
180 lim
->seg_boundary_mask
= BLK_SEG_BOUNDARY_MASK
;
181 if (WARN_ON_ONCE(lim
->seg_boundary_mask
< PAGE_SIZE
- 1))
185 * Stacking device may have both virtual boundary and max segment
186 * size limit, so allow this setting now, and long-term the two
187 * might need to move out of stacking limits since we have immutable
188 * bvec and lower layer bio splitting is supposed to handle the two
191 if (!lim
->virt_boundary_mask
) {
193 * The maximum segment size has an odd historic 64k default that
194 * drivers probably should override. Just like the I/O size we
195 * require drivers to at least handle a full page per segment.
197 if (!lim
->max_segment_size
)
198 lim
->max_segment_size
= BLK_MAX_SEGMENT_SIZE
;
199 if (WARN_ON_ONCE(lim
->max_segment_size
< PAGE_SIZE
))
204 * We require drivers to at least do logical block aligned I/O, but
205 * historically could not check for that due to the separate calls
206 * to set the limits. Once the transition is finished the check
207 * below should be narrowed down to check the logical block size.
209 if (!lim
->dma_alignment
)
210 lim
->dma_alignment
= SECTOR_SIZE
- 1;
211 if (WARN_ON_ONCE(lim
->dma_alignment
> PAGE_SIZE
))
214 if (lim
->alignment_offset
) {
215 lim
->alignment_offset
&= (lim
->physical_block_size
- 1);
219 return blk_validate_zoned_limits(lim
);
223 * Set the default limits for a newly allocated queue. @lim contains the
224 * initial limits set by the driver, which could be no limit in which case
225 * all fields are cleared to zero.
227 int blk_set_default_limits(struct queue_limits
*lim
)
230 * Most defaults are set by capping the bounds in blk_validate_limits,
231 * but max_user_discard_sectors is special and needs an explicit
232 * initialization to the max value here.
234 lim
->max_user_discard_sectors
= UINT_MAX
;
235 return blk_validate_limits(lim
);
239 * queue_limits_commit_update - commit an atomic update of queue limits
240 * @q: queue to update
241 * @lim: limits to apply
243 * Apply the limits in @lim that were obtained from queue_limits_start_update()
244 * and updated by the caller to @q.
246 * Returns 0 if successful, else a negative error code.
248 int queue_limits_commit_update(struct request_queue
*q
,
249 struct queue_limits
*lim
)
250 __releases(q
->limits_lock
)
252 int error
= blk_validate_limits(lim
);
257 blk_apply_bdi_limits(q
->disk
->bdi
, lim
);
259 mutex_unlock(&q
->limits_lock
);
262 EXPORT_SYMBOL_GPL(queue_limits_commit_update
);
265 * queue_limits_set - apply queue limits to queue
266 * @q: queue to update
267 * @lim: limits to apply
269 * Apply the limits in @lim that were freshly initialized to @q.
270 * To update existing limits use queue_limits_start_update() and
271 * queue_limits_commit_update() instead.
273 * Returns 0 if successful, else a negative error code.
275 int queue_limits_set(struct request_queue
*q
, struct queue_limits
*lim
)
277 mutex_lock(&q
->limits_lock
);
278 return queue_limits_commit_update(q
, lim
);
280 EXPORT_SYMBOL_GPL(queue_limits_set
);
283 * blk_queue_bounce_limit - set bounce buffer limit for queue
284 * @q: the request queue for the device
285 * @bounce: bounce limit to enforce
288 * Force bouncing for ISA DMA ranges or highmem.
290 * DEPRECATED, don't use in new code.
292 void blk_queue_bounce_limit(struct request_queue
*q
, enum blk_bounce bounce
)
294 q
->limits
.bounce
= bounce
;
296 EXPORT_SYMBOL(blk_queue_bounce_limit
);
299 * blk_queue_max_hw_sectors - set max sectors for a request for this queue
300 * @q: the request queue for the device
301 * @max_hw_sectors: max hardware sectors in the usual 512b unit
304 * Enables a low level driver to set a hard upper limit,
305 * max_hw_sectors, on the size of requests. max_hw_sectors is set by
306 * the device driver based upon the capabilities of the I/O
309 * max_dev_sectors is a hard limit imposed by the storage device for
310 * READ/WRITE requests. It is set by the disk driver.
312 * max_sectors is a soft limit imposed by the block layer for
313 * filesystem type requests. This value can be overridden on a
314 * per-device basis in /sys/block/<device>/queue/max_sectors_kb.
315 * The soft limit can not exceed max_hw_sectors.
317 void blk_queue_max_hw_sectors(struct request_queue
*q
, unsigned int max_hw_sectors
)
319 struct queue_limits
*limits
= &q
->limits
;
320 unsigned int max_sectors
;
322 if ((max_hw_sectors
<< 9) < PAGE_SIZE
) {
323 max_hw_sectors
= 1 << (PAGE_SHIFT
- 9);
324 pr_info("%s: set to minimum %u\n", __func__
, max_hw_sectors
);
327 max_hw_sectors
= round_down(max_hw_sectors
,
328 limits
->logical_block_size
>> SECTOR_SHIFT
);
329 limits
->max_hw_sectors
= max_hw_sectors
;
331 max_sectors
= min_not_zero(max_hw_sectors
, limits
->max_dev_sectors
);
333 if (limits
->max_user_sectors
)
334 max_sectors
= min(max_sectors
, limits
->max_user_sectors
);
336 max_sectors
= min(max_sectors
, BLK_DEF_MAX_SECTORS_CAP
);
338 max_sectors
= round_down(max_sectors
,
339 limits
->logical_block_size
>> SECTOR_SHIFT
);
340 limits
->max_sectors
= max_sectors
;
344 q
->disk
->bdi
->io_pages
= max_sectors
>> (PAGE_SHIFT
- 9);
346 EXPORT_SYMBOL(blk_queue_max_hw_sectors
);
349 * blk_queue_chunk_sectors - set size of the chunk for this queue
350 * @q: the request queue for the device
351 * @chunk_sectors: chunk sectors in the usual 512b unit
354 * If a driver doesn't want IOs to cross a given chunk size, it can set
355 * this limit and prevent merging across chunks. Note that the block layer
356 * must accept a page worth of data at any offset. So if the crossing of
357 * chunks is a hard limitation in the driver, it must still be prepared
358 * to split single page bios.
360 void blk_queue_chunk_sectors(struct request_queue
*q
, unsigned int chunk_sectors
)
362 q
->limits
.chunk_sectors
= chunk_sectors
;
364 EXPORT_SYMBOL(blk_queue_chunk_sectors
);
367 * blk_queue_max_discard_sectors - set max sectors for a single discard
368 * @q: the request queue for the device
369 * @max_discard_sectors: maximum number of sectors to discard
371 void blk_queue_max_discard_sectors(struct request_queue
*q
,
372 unsigned int max_discard_sectors
)
374 struct queue_limits
*lim
= &q
->limits
;
376 lim
->max_hw_discard_sectors
= max_discard_sectors
;
377 lim
->max_discard_sectors
=
378 min(max_discard_sectors
, lim
->max_user_discard_sectors
);
380 EXPORT_SYMBOL(blk_queue_max_discard_sectors
);
383 * blk_queue_max_secure_erase_sectors - set max sectors for a secure erase
384 * @q: the request queue for the device
385 * @max_sectors: maximum number of sectors to secure_erase
387 void blk_queue_max_secure_erase_sectors(struct request_queue
*q
,
388 unsigned int max_sectors
)
390 q
->limits
.max_secure_erase_sectors
= max_sectors
;
392 EXPORT_SYMBOL(blk_queue_max_secure_erase_sectors
);
395 * blk_queue_max_write_zeroes_sectors - set max sectors for a single
397 * @q: the request queue for the device
398 * @max_write_zeroes_sectors: maximum number of sectors to write per command
400 void blk_queue_max_write_zeroes_sectors(struct request_queue
*q
,
401 unsigned int max_write_zeroes_sectors
)
403 q
->limits
.max_write_zeroes_sectors
= max_write_zeroes_sectors
;
405 EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors
);
408 * blk_queue_max_zone_append_sectors - set max sectors for a single zone append
409 * @q: the request queue for the device
410 * @max_zone_append_sectors: maximum number of sectors to write per command
412 void blk_queue_max_zone_append_sectors(struct request_queue
*q
,
413 unsigned int max_zone_append_sectors
)
415 unsigned int max_sectors
;
417 if (WARN_ON(!blk_queue_is_zoned(q
)))
420 max_sectors
= min(q
->limits
.max_hw_sectors
, max_zone_append_sectors
);
421 max_sectors
= min(q
->limits
.chunk_sectors
, max_sectors
);
424 * Signal eventual driver bugs resulting in the max_zone_append sectors limit
425 * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set,
426 * or the max_hw_sectors limit not set.
428 WARN_ON(!max_sectors
);
430 q
->limits
.max_zone_append_sectors
= max_sectors
;
432 EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors
);
435 * blk_queue_max_segments - set max hw segments for a request for this queue
436 * @q: the request queue for the device
437 * @max_segments: max number of segments
440 * Enables a low level driver to set an upper limit on the number of
441 * hw data segments in a request.
443 void blk_queue_max_segments(struct request_queue
*q
, unsigned short max_segments
)
447 pr_info("%s: set to minimum %u\n", __func__
, max_segments
);
450 q
->limits
.max_segments
= max_segments
;
452 EXPORT_SYMBOL(blk_queue_max_segments
);
455 * blk_queue_max_discard_segments - set max segments for discard requests
456 * @q: the request queue for the device
457 * @max_segments: max number of segments
460 * Enables a low level driver to set an upper limit on the number of
461 * segments in a discard request.
463 void blk_queue_max_discard_segments(struct request_queue
*q
,
464 unsigned short max_segments
)
466 q
->limits
.max_discard_segments
= max_segments
;
468 EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments
);
471 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
472 * @q: the request queue for the device
473 * @max_size: max size of segment in bytes
476 * Enables a low level driver to set an upper limit on the size of a
479 void blk_queue_max_segment_size(struct request_queue
*q
, unsigned int max_size
)
481 if (max_size
< PAGE_SIZE
) {
482 max_size
= PAGE_SIZE
;
483 pr_info("%s: set to minimum %u\n", __func__
, max_size
);
486 /* see blk_queue_virt_boundary() for the explanation */
487 WARN_ON_ONCE(q
->limits
.virt_boundary_mask
);
489 q
->limits
.max_segment_size
= max_size
;
491 EXPORT_SYMBOL(blk_queue_max_segment_size
);
494 * blk_queue_logical_block_size - set logical block size for the queue
495 * @q: the request queue for the device
496 * @size: the logical block size, in bytes
499 * This should be set to the lowest possible block size that the
500 * storage device can address. The default of 512 covers most
503 void blk_queue_logical_block_size(struct request_queue
*q
, unsigned int size
)
505 struct queue_limits
*limits
= &q
->limits
;
507 limits
->logical_block_size
= size
;
509 if (limits
->discard_granularity
< limits
->logical_block_size
)
510 limits
->discard_granularity
= limits
->logical_block_size
;
512 if (limits
->physical_block_size
< size
)
513 limits
->physical_block_size
= size
;
515 if (limits
->io_min
< limits
->physical_block_size
)
516 limits
->io_min
= limits
->physical_block_size
;
518 limits
->max_hw_sectors
=
519 round_down(limits
->max_hw_sectors
, size
>> SECTOR_SHIFT
);
520 limits
->max_sectors
=
521 round_down(limits
->max_sectors
, size
>> SECTOR_SHIFT
);
523 EXPORT_SYMBOL(blk_queue_logical_block_size
);
526 * blk_queue_physical_block_size - set physical block size for the queue
527 * @q: the request queue for the device
528 * @size: the physical block size, in bytes
531 * This should be set to the lowest possible sector size that the
532 * hardware can operate on without reverting to read-modify-write
535 void blk_queue_physical_block_size(struct request_queue
*q
, unsigned int size
)
537 q
->limits
.physical_block_size
= size
;
539 if (q
->limits
.physical_block_size
< q
->limits
.logical_block_size
)
540 q
->limits
.physical_block_size
= q
->limits
.logical_block_size
;
542 if (q
->limits
.discard_granularity
< q
->limits
.physical_block_size
)
543 q
->limits
.discard_granularity
= q
->limits
.physical_block_size
;
545 if (q
->limits
.io_min
< q
->limits
.physical_block_size
)
546 q
->limits
.io_min
= q
->limits
.physical_block_size
;
548 EXPORT_SYMBOL(blk_queue_physical_block_size
);
551 * blk_queue_zone_write_granularity - set zone write granularity for the queue
552 * @q: the request queue for the zoned device
553 * @size: the zone write granularity size, in bytes
556 * This should be set to the lowest possible size allowing to write in
557 * sequential zones of a zoned block device.
559 void blk_queue_zone_write_granularity(struct request_queue
*q
,
562 if (WARN_ON_ONCE(!blk_queue_is_zoned(q
)))
565 q
->limits
.zone_write_granularity
= size
;
567 if (q
->limits
.zone_write_granularity
< q
->limits
.logical_block_size
)
568 q
->limits
.zone_write_granularity
= q
->limits
.logical_block_size
;
570 EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity
);
573 * blk_queue_alignment_offset - set physical block alignment offset
574 * @q: the request queue for the device
575 * @offset: alignment offset in bytes
578 * Some devices are naturally misaligned to compensate for things like
579 * the legacy DOS partition table 63-sector offset. Low-level drivers
580 * should call this function for devices whose first sector is not
583 void blk_queue_alignment_offset(struct request_queue
*q
, unsigned int offset
)
585 q
->limits
.alignment_offset
=
586 offset
& (q
->limits
.physical_block_size
- 1);
587 q
->limits
.misaligned
= 0;
589 EXPORT_SYMBOL(blk_queue_alignment_offset
);
591 void disk_update_readahead(struct gendisk
*disk
)
593 blk_apply_bdi_limits(disk
->bdi
, &disk
->queue
->limits
);
595 EXPORT_SYMBOL_GPL(disk_update_readahead
);
598 * blk_limits_io_min - set minimum request size for a device
599 * @limits: the queue limits
600 * @min: smallest I/O size in bytes
603 * Some devices have an internal block size bigger than the reported
604 * hardware sector size. This function can be used to signal the
605 * smallest I/O the device can perform without incurring a performance
608 void blk_limits_io_min(struct queue_limits
*limits
, unsigned int min
)
610 limits
->io_min
= min
;
612 if (limits
->io_min
< limits
->logical_block_size
)
613 limits
->io_min
= limits
->logical_block_size
;
615 if (limits
->io_min
< limits
->physical_block_size
)
616 limits
->io_min
= limits
->physical_block_size
;
618 EXPORT_SYMBOL(blk_limits_io_min
);
621 * blk_queue_io_min - set minimum request size for the queue
622 * @q: the request queue for the device
623 * @min: smallest I/O size in bytes
626 * Storage devices may report a granularity or preferred minimum I/O
627 * size which is the smallest request the device can perform without
628 * incurring a performance penalty. For disk drives this is often the
629 * physical block size. For RAID arrays it is often the stripe chunk
630 * size. A properly aligned multiple of minimum_io_size is the
631 * preferred request size for workloads where a high number of I/O
632 * operations is desired.
634 void blk_queue_io_min(struct request_queue
*q
, unsigned int min
)
636 blk_limits_io_min(&q
->limits
, min
);
638 EXPORT_SYMBOL(blk_queue_io_min
);
641 * blk_limits_io_opt - set optimal request size for a device
642 * @limits: the queue limits
643 * @opt: smallest I/O size in bytes
646 * Storage devices may report an optimal I/O size, which is the
647 * device's preferred unit for sustained I/O. This is rarely reported
648 * for disk drives. For RAID arrays it is usually the stripe width or
649 * the internal track size. A properly aligned multiple of
650 * optimal_io_size is the preferred request size for workloads where
651 * sustained throughput is desired.
653 void blk_limits_io_opt(struct queue_limits
*limits
, unsigned int opt
)
655 limits
->io_opt
= opt
;
657 EXPORT_SYMBOL(blk_limits_io_opt
);
660 * blk_queue_io_opt - set optimal request size for the queue
661 * @q: the request queue for the device
662 * @opt: optimal request size in bytes
665 * Storage devices may report an optimal I/O size, which is the
666 * device's preferred unit for sustained I/O. This is rarely reported
667 * for disk drives. For RAID arrays it is usually the stripe width or
668 * the internal track size. A properly aligned multiple of
669 * optimal_io_size is the preferred request size for workloads where
670 * sustained throughput is desired.
672 void blk_queue_io_opt(struct request_queue
*q
, unsigned int opt
)
674 blk_limits_io_opt(&q
->limits
, opt
);
677 q
->disk
->bdi
->ra_pages
=
678 max(queue_io_opt(q
) * 2 / PAGE_SIZE
, VM_READAHEAD_PAGES
);
680 EXPORT_SYMBOL(blk_queue_io_opt
);
682 static int queue_limit_alignment_offset(const struct queue_limits
*lim
,
685 unsigned int granularity
= max(lim
->physical_block_size
, lim
->io_min
);
686 unsigned int alignment
= sector_div(sector
, granularity
>> SECTOR_SHIFT
)
689 return (granularity
+ lim
->alignment_offset
- alignment
) % granularity
;
692 static unsigned int queue_limit_discard_alignment(
693 const struct queue_limits
*lim
, sector_t sector
)
695 unsigned int alignment
, granularity
, offset
;
697 if (!lim
->max_discard_sectors
)
700 /* Why are these in bytes, not sectors? */
701 alignment
= lim
->discard_alignment
>> SECTOR_SHIFT
;
702 granularity
= lim
->discard_granularity
>> SECTOR_SHIFT
;
706 /* Offset of the partition start in 'granularity' sectors */
707 offset
= sector_div(sector
, granularity
);
709 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
710 offset
= (granularity
+ alignment
- offset
) % granularity
;
712 /* Turn it back into bytes, gaah */
713 return offset
<< SECTOR_SHIFT
;
716 static unsigned int blk_round_down_sectors(unsigned int sectors
, unsigned int lbs
)
718 sectors
= round_down(sectors
, lbs
>> SECTOR_SHIFT
);
719 if (sectors
< PAGE_SIZE
>> SECTOR_SHIFT
)
720 sectors
= PAGE_SIZE
>> SECTOR_SHIFT
;
725 * blk_stack_limits - adjust queue_limits for stacked devices
726 * @t: the stacking driver limits (top device)
727 * @b: the underlying queue limits (bottom, component device)
728 * @start: first data sector within component device
731 * This function is used by stacking drivers like MD and DM to ensure
732 * that all component devices have compatible block sizes and
733 * alignments. The stacking driver must provide a queue_limits
734 * struct (top) and then iteratively call the stacking function for
735 * all component (bottom) devices. The stacking function will
736 * attempt to combine the values and ensure proper alignment.
738 * Returns 0 if the top and bottom queue_limits are compatible. The
739 * top device's block sizes and alignment offsets may be adjusted to
740 * ensure alignment with the bottom device. If no compatible sizes
741 * and alignments exist, -1 is returned and the resulting top
742 * queue_limits will have the misaligned flag set to indicate that
743 * the alignment_offset is undefined.
745 int blk_stack_limits(struct queue_limits
*t
, struct queue_limits
*b
,
748 unsigned int top
, bottom
, alignment
, ret
= 0;
750 t
->max_sectors
= min_not_zero(t
->max_sectors
, b
->max_sectors
);
751 t
->max_hw_sectors
= min_not_zero(t
->max_hw_sectors
, b
->max_hw_sectors
);
752 t
->max_dev_sectors
= min_not_zero(t
->max_dev_sectors
, b
->max_dev_sectors
);
753 t
->max_write_zeroes_sectors
= min(t
->max_write_zeroes_sectors
,
754 b
->max_write_zeroes_sectors
);
755 t
->max_zone_append_sectors
= min(t
->max_zone_append_sectors
,
756 b
->max_zone_append_sectors
);
757 t
->bounce
= max(t
->bounce
, b
->bounce
);
759 t
->seg_boundary_mask
= min_not_zero(t
->seg_boundary_mask
,
760 b
->seg_boundary_mask
);
761 t
->virt_boundary_mask
= min_not_zero(t
->virt_boundary_mask
,
762 b
->virt_boundary_mask
);
764 t
->max_segments
= min_not_zero(t
->max_segments
, b
->max_segments
);
765 t
->max_discard_segments
= min_not_zero(t
->max_discard_segments
,
766 b
->max_discard_segments
);
767 t
->max_integrity_segments
= min_not_zero(t
->max_integrity_segments
,
768 b
->max_integrity_segments
);
770 t
->max_segment_size
= min_not_zero(t
->max_segment_size
,
771 b
->max_segment_size
);
773 t
->misaligned
|= b
->misaligned
;
775 alignment
= queue_limit_alignment_offset(b
, start
);
777 /* Bottom device has different alignment. Check that it is
778 * compatible with the current top alignment.
780 if (t
->alignment_offset
!= alignment
) {
782 top
= max(t
->physical_block_size
, t
->io_min
)
783 + t
->alignment_offset
;
784 bottom
= max(b
->physical_block_size
, b
->io_min
) + alignment
;
786 /* Verify that top and bottom intervals line up */
787 if (max(top
, bottom
) % min(top
, bottom
)) {
793 t
->logical_block_size
= max(t
->logical_block_size
,
794 b
->logical_block_size
);
796 t
->physical_block_size
= max(t
->physical_block_size
,
797 b
->physical_block_size
);
799 t
->io_min
= max(t
->io_min
, b
->io_min
);
800 t
->io_opt
= lcm_not_zero(t
->io_opt
, b
->io_opt
);
801 t
->dma_alignment
= max(t
->dma_alignment
, b
->dma_alignment
);
803 /* Set non-power-of-2 compatible chunk_sectors boundary */
804 if (b
->chunk_sectors
)
805 t
->chunk_sectors
= gcd(t
->chunk_sectors
, b
->chunk_sectors
);
807 /* Physical block size a multiple of the logical block size? */
808 if (t
->physical_block_size
& (t
->logical_block_size
- 1)) {
809 t
->physical_block_size
= t
->logical_block_size
;
814 /* Minimum I/O a multiple of the physical block size? */
815 if (t
->io_min
& (t
->physical_block_size
- 1)) {
816 t
->io_min
= t
->physical_block_size
;
821 /* Optimal I/O a multiple of the physical block size? */
822 if (t
->io_opt
& (t
->physical_block_size
- 1)) {
828 /* chunk_sectors a multiple of the physical block size? */
829 if ((t
->chunk_sectors
<< 9) & (t
->physical_block_size
- 1)) {
830 t
->chunk_sectors
= 0;
835 t
->raid_partial_stripes_expensive
=
836 max(t
->raid_partial_stripes_expensive
,
837 b
->raid_partial_stripes_expensive
);
839 /* Find lowest common alignment_offset */
840 t
->alignment_offset
= lcm_not_zero(t
->alignment_offset
, alignment
)
841 % max(t
->physical_block_size
, t
->io_min
);
843 /* Verify that new alignment_offset is on a logical block boundary */
844 if (t
->alignment_offset
& (t
->logical_block_size
- 1)) {
849 t
->max_sectors
= blk_round_down_sectors(t
->max_sectors
, t
->logical_block_size
);
850 t
->max_hw_sectors
= blk_round_down_sectors(t
->max_hw_sectors
, t
->logical_block_size
);
851 t
->max_dev_sectors
= blk_round_down_sectors(t
->max_dev_sectors
, t
->logical_block_size
);
853 /* Discard alignment and granularity */
854 if (b
->discard_granularity
) {
855 alignment
= queue_limit_discard_alignment(b
, start
);
857 if (t
->discard_granularity
!= 0 &&
858 t
->discard_alignment
!= alignment
) {
859 top
= t
->discard_granularity
+ t
->discard_alignment
;
860 bottom
= b
->discard_granularity
+ alignment
;
862 /* Verify that top and bottom intervals line up */
863 if ((max(top
, bottom
) % min(top
, bottom
)) != 0)
864 t
->discard_misaligned
= 1;
867 t
->max_discard_sectors
= min_not_zero(t
->max_discard_sectors
,
868 b
->max_discard_sectors
);
869 t
->max_hw_discard_sectors
= min_not_zero(t
->max_hw_discard_sectors
,
870 b
->max_hw_discard_sectors
);
871 t
->discard_granularity
= max(t
->discard_granularity
,
872 b
->discard_granularity
);
873 t
->discard_alignment
= lcm_not_zero(t
->discard_alignment
, alignment
) %
874 t
->discard_granularity
;
876 t
->max_secure_erase_sectors
= min_not_zero(t
->max_secure_erase_sectors
,
877 b
->max_secure_erase_sectors
);
878 t
->zone_write_granularity
= max(t
->zone_write_granularity
,
879 b
->zone_write_granularity
);
880 t
->zoned
= max(t
->zoned
, b
->zoned
);
882 t
->zone_write_granularity
= 0;
883 t
->max_zone_append_sectors
= 0;
887 EXPORT_SYMBOL(blk_stack_limits
);
890 * queue_limits_stack_bdev - adjust queue_limits for stacked devices
891 * @t: the stacking driver limits (top device)
892 * @bdev: the underlying block device (bottom)
893 * @offset: offset to beginning of data within component device
894 * @pfx: prefix to use for warnings logged
897 * This function is used by stacking drivers like MD and DM to ensure
898 * that all component devices have compatible block sizes and
899 * alignments. The stacking driver must provide a queue_limits
900 * struct (top) and then iteratively call the stacking function for
901 * all component (bottom) devices. The stacking function will
902 * attempt to combine the values and ensure proper alignment.
904 void queue_limits_stack_bdev(struct queue_limits
*t
, struct block_device
*bdev
,
905 sector_t offset
, const char *pfx
)
907 if (blk_stack_limits(t
, &bdev_get_queue(bdev
)->limits
,
908 get_start_sect(bdev
) + offset
))
909 pr_notice("%s: Warning: Device %pg is misaligned\n",
912 EXPORT_SYMBOL_GPL(queue_limits_stack_bdev
);
915 * blk_queue_update_dma_pad - update pad mask
916 * @q: the request queue for the device
919 * Update dma pad mask.
921 * Appending pad buffer to a request modifies the last entry of a
922 * scatter list such that it includes the pad buffer.
924 void blk_queue_update_dma_pad(struct request_queue
*q
, unsigned int mask
)
926 if (mask
> q
->dma_pad_mask
)
927 q
->dma_pad_mask
= mask
;
929 EXPORT_SYMBOL(blk_queue_update_dma_pad
);
932 * blk_queue_segment_boundary - set boundary rules for segment merging
933 * @q: the request queue for the device
934 * @mask: the memory boundary mask
936 void blk_queue_segment_boundary(struct request_queue
*q
, unsigned long mask
)
938 if (mask
< PAGE_SIZE
- 1) {
939 mask
= PAGE_SIZE
- 1;
940 pr_info("%s: set to minimum %lx\n", __func__
, mask
);
943 q
->limits
.seg_boundary_mask
= mask
;
945 EXPORT_SYMBOL(blk_queue_segment_boundary
);
948 * blk_queue_virt_boundary - set boundary rules for bio merging
949 * @q: the request queue for the device
950 * @mask: the memory boundary mask
952 void blk_queue_virt_boundary(struct request_queue
*q
, unsigned long mask
)
954 q
->limits
.virt_boundary_mask
= mask
;
957 * Devices that require a virtual boundary do not support scatter/gather
958 * I/O natively, but instead require a descriptor list entry for each
959 * page (which might not be idential to the Linux PAGE_SIZE). Because
960 * of that they are not limited by our notion of "segment size".
963 q
->limits
.max_segment_size
= UINT_MAX
;
965 EXPORT_SYMBOL(blk_queue_virt_boundary
);
968 * blk_queue_dma_alignment - set dma length and memory alignment
969 * @q: the request queue for the device
970 * @mask: alignment mask
973 * set required memory and length alignment for direct dma transactions.
974 * this is used when building direct io requests for the queue.
977 void blk_queue_dma_alignment(struct request_queue
*q
, int mask
)
979 q
->limits
.dma_alignment
= mask
;
981 EXPORT_SYMBOL(blk_queue_dma_alignment
);
984 * blk_queue_update_dma_alignment - update dma length and memory alignment
985 * @q: the request queue for the device
986 * @mask: alignment mask
989 * update required memory and length alignment for direct dma transactions.
990 * If the requested alignment is larger than the current alignment, then
991 * the current queue alignment is updated to the new value, otherwise it
992 * is left alone. The design of this is to allow multiple objects
993 * (driver, device, transport etc) to set their respective
994 * alignments without having them interfere.
997 void blk_queue_update_dma_alignment(struct request_queue
*q
, int mask
)
999 BUG_ON(mask
> PAGE_SIZE
);
1001 if (mask
> q
->limits
.dma_alignment
)
1002 q
->limits
.dma_alignment
= mask
;
1004 EXPORT_SYMBOL(blk_queue_update_dma_alignment
);
1007 * blk_set_queue_depth - tell the block layer about the device queue depth
1008 * @q: the request queue for the device
1009 * @depth: queue depth
1012 void blk_set_queue_depth(struct request_queue
*q
, unsigned int depth
)
1014 q
->queue_depth
= depth
;
1015 rq_qos_queue_depth_changed(q
);
1017 EXPORT_SYMBOL(blk_set_queue_depth
);
1020 * blk_queue_write_cache - configure queue's write cache
1021 * @q: the request queue for the device
1022 * @wc: write back cache on or off
1023 * @fua: device supports FUA writes, if true
1025 * Tell the block layer about the write cache of @q.
1027 void blk_queue_write_cache(struct request_queue
*q
, bool wc
, bool fua
)
1030 blk_queue_flag_set(QUEUE_FLAG_HW_WC
, q
);
1031 blk_queue_flag_set(QUEUE_FLAG_WC
, q
);
1033 blk_queue_flag_clear(QUEUE_FLAG_HW_WC
, q
);
1034 blk_queue_flag_clear(QUEUE_FLAG_WC
, q
);
1037 blk_queue_flag_set(QUEUE_FLAG_FUA
, q
);
1039 blk_queue_flag_clear(QUEUE_FLAG_FUA
, q
);
1041 EXPORT_SYMBOL_GPL(blk_queue_write_cache
);
1044 * blk_queue_required_elevator_features - Set a queue required elevator features
1045 * @q: the request queue for the target device
1046 * @features: Required elevator features OR'ed together
1048 * Tell the block layer that for the device controlled through @q, only the
1049 * only elevators that can be used are those that implement at least the set of
1050 * features specified by @features.
1052 void blk_queue_required_elevator_features(struct request_queue
*q
,
1053 unsigned int features
)
1055 q
->required_elevator_features
= features
;
1057 EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features
);
1060 * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
1061 * @q: the request queue for the device
1062 * @dev: the device pointer for dma
1064 * Tell the block layer about merging the segments by dma map of @q.
1066 bool blk_queue_can_use_dma_map_merging(struct request_queue
*q
,
1069 unsigned long boundary
= dma_get_merge_boundary(dev
);
1074 /* No need to update max_segment_size. see blk_queue_virt_boundary() */
1075 blk_queue_virt_boundary(q
, boundary
);
1079 EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging
);
1082 * disk_set_zoned - inidicate a zoned device
1083 * @disk: gendisk to configure
1085 void disk_set_zoned(struct gendisk
*disk
)
1087 struct request_queue
*q
= disk
->queue
;
1089 WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED
));
1092 * Set the zone write granularity to the device logical block
1093 * size by default. The driver can change this value if needed.
1095 q
->limits
.zoned
= true;
1096 blk_queue_zone_write_granularity(q
, queue_logical_block_size(q
));
1098 EXPORT_SYMBOL_GPL(disk_set_zoned
);
1100 int bdev_alignment_offset(struct block_device
*bdev
)
1102 struct request_queue
*q
= bdev_get_queue(bdev
);
1104 if (q
->limits
.misaligned
)
1106 if (bdev_is_partition(bdev
))
1107 return queue_limit_alignment_offset(&q
->limits
,
1108 bdev
->bd_start_sect
);
1109 return q
->limits
.alignment_offset
;
1111 EXPORT_SYMBOL_GPL(bdev_alignment_offset
);
1113 unsigned int bdev_discard_alignment(struct block_device
*bdev
)
1115 struct request_queue
*q
= bdev_get_queue(bdev
);
1117 if (bdev_is_partition(bdev
))
1118 return queue_limit_discard_alignment(&q
->limits
,
1119 bdev
->bd_start_sect
);
1120 return q
->limits
.discard_alignment
;
1122 EXPORT_SYMBOL_GPL(bdev_discard_alignment
);