Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Functions related to setting various queue properties from drivers
4 : */
5 : #include <linux/kernel.h>
6 : #include <linux/module.h>
7 : #include <linux/init.h>
8 : #include <linux/bio.h>
9 : #include <linux/blkdev.h>
10 : #include <linux/pagemap.h>
11 : #include <linux/backing-dev-defs.h>
12 : #include <linux/gcd.h>
13 : #include <linux/lcm.h>
14 : #include <linux/jiffies.h>
15 : #include <linux/gfp.h>
16 : #include <linux/dma-mapping.h>
17 :
18 : #include "blk.h"
19 : #include "blk-rq-qos.h"
20 : #include "blk-wbt.h"
21 :
22 0 : void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
23 : {
24 0 : q->rq_timeout = timeout;
25 0 : }
26 : EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
27 :
28 : /**
29 : * blk_set_default_limits - reset limits to default values
30 : * @lim: the queue_limits structure to reset
31 : *
32 : * Description:
33 : * Returns a queue_limit struct to its default state.
34 : */
35 0 : void blk_set_default_limits(struct queue_limits *lim)
36 : {
37 0 : lim->max_segments = BLK_MAX_SEGMENTS;
38 0 : lim->max_discard_segments = 1;
39 0 : lim->max_integrity_segments = 0;
40 0 : lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
41 0 : lim->virt_boundary_mask = 0;
42 0 : lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
43 0 : lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
44 0 : lim->max_user_sectors = lim->max_dev_sectors = 0;
45 0 : lim->chunk_sectors = 0;
46 0 : lim->max_write_zeroes_sectors = 0;
47 0 : lim->max_zone_append_sectors = 0;
48 0 : lim->max_discard_sectors = 0;
49 0 : lim->max_hw_discard_sectors = 0;
50 0 : lim->max_secure_erase_sectors = 0;
51 0 : lim->discard_granularity = 0;
52 0 : lim->discard_alignment = 0;
53 0 : lim->discard_misaligned = 0;
54 0 : lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
55 0 : lim->bounce = BLK_BOUNCE_NONE;
56 0 : lim->alignment_offset = 0;
57 0 : lim->io_opt = 0;
58 0 : lim->misaligned = 0;
59 0 : lim->zoned = BLK_ZONED_NONE;
60 0 : lim->zone_write_granularity = 0;
61 0 : lim->dma_alignment = 511;
62 0 : }
63 :
64 : /**
65 : * blk_set_stacking_limits - set default limits for stacking devices
66 : * @lim: the queue_limits structure to reset
67 : *
68 : * Description:
69 : * Returns a queue_limit struct to its default state. Should be used
70 : * by stacking drivers like DM that have no internal limits.
71 : */
72 0 : void blk_set_stacking_limits(struct queue_limits *lim)
73 : {
74 0 : blk_set_default_limits(lim);
75 :
76 : /* Inherit limits from component devices */
77 0 : lim->max_segments = USHRT_MAX;
78 0 : lim->max_discard_segments = USHRT_MAX;
79 0 : lim->max_hw_sectors = UINT_MAX;
80 0 : lim->max_segment_size = UINT_MAX;
81 0 : lim->max_sectors = UINT_MAX;
82 0 : lim->max_dev_sectors = UINT_MAX;
83 0 : lim->max_write_zeroes_sectors = UINT_MAX;
84 0 : lim->max_zone_append_sectors = UINT_MAX;
85 0 : }
86 : EXPORT_SYMBOL(blk_set_stacking_limits);
87 :
88 : /**
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
92 : *
93 : * Description:
94 : * Force bouncing for ISA DMA ranges or highmem.
95 : *
96 : * DEPRECATED, don't use in new code.
97 : **/
98 0 : void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce bounce)
99 : {
100 0 : q->limits.bounce = bounce;
101 0 : }
102 : EXPORT_SYMBOL(blk_queue_bounce_limit);
103 :
104 : /**
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
108 : *
109 : * Description:
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
113 : * controller.
114 : *
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.
117 : *
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.
122 : **/
123 0 : void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
124 : {
125 0 : struct queue_limits *limits = &q->limits;
126 : unsigned int max_sectors;
127 :
128 0 : if ((max_hw_sectors << 9) < PAGE_SIZE) {
129 0 : max_hw_sectors = 1 << (PAGE_SHIFT - 9);
130 0 : printk(KERN_INFO "%s: set to minimum %d\n",
131 : __func__, max_hw_sectors);
132 : }
133 :
134 0 : max_hw_sectors = round_down(max_hw_sectors,
135 : limits->logical_block_size >> SECTOR_SHIFT);
136 0 : limits->max_hw_sectors = max_hw_sectors;
137 :
138 0 : max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
139 :
140 0 : if (limits->max_user_sectors)
141 0 : max_sectors = min(max_sectors, limits->max_user_sectors);
142 : else
143 0 : max_sectors = min(max_sectors, BLK_DEF_MAX_SECTORS);
144 :
145 0 : max_sectors = round_down(max_sectors,
146 : limits->logical_block_size >> SECTOR_SHIFT);
147 0 : limits->max_sectors = max_sectors;
148 :
149 0 : if (!q->disk)
150 : return;
151 0 : q->disk->bdi->io_pages = max_sectors >> (PAGE_SHIFT - 9);
152 : }
153 : EXPORT_SYMBOL(blk_queue_max_hw_sectors);
154 :
155 : /**
156 : * blk_queue_chunk_sectors - set size of the chunk for this queue
157 : * @q: the request queue for the device
158 : * @chunk_sectors: chunk sectors in the usual 512b unit
159 : *
160 : * Description:
161 : * If a driver doesn't want IOs to cross a given chunk size, it can set
162 : * this limit and prevent merging across chunks. Note that the block layer
163 : * must accept a page worth of data at any offset. So if the crossing of
164 : * chunks is a hard limitation in the driver, it must still be prepared
165 : * to split single page bios.
166 : **/
167 0 : void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
168 : {
169 0 : q->limits.chunk_sectors = chunk_sectors;
170 0 : }
171 : EXPORT_SYMBOL(blk_queue_chunk_sectors);
172 :
173 : /**
174 : * blk_queue_max_discard_sectors - set max sectors for a single discard
175 : * @q: the request queue for the device
176 : * @max_discard_sectors: maximum number of sectors to discard
177 : **/
178 0 : void blk_queue_max_discard_sectors(struct request_queue *q,
179 : unsigned int max_discard_sectors)
180 : {
181 0 : q->limits.max_hw_discard_sectors = max_discard_sectors;
182 0 : q->limits.max_discard_sectors = max_discard_sectors;
183 0 : }
184 : EXPORT_SYMBOL(blk_queue_max_discard_sectors);
185 :
186 : /**
187 : * blk_queue_max_secure_erase_sectors - set max sectors for a secure erase
188 : * @q: the request queue for the device
189 : * @max_sectors: maximum number of sectors to secure_erase
190 : **/
191 0 : void blk_queue_max_secure_erase_sectors(struct request_queue *q,
192 : unsigned int max_sectors)
193 : {
194 0 : q->limits.max_secure_erase_sectors = max_sectors;
195 0 : }
196 : EXPORT_SYMBOL(blk_queue_max_secure_erase_sectors);
197 :
198 : /**
199 : * blk_queue_max_write_zeroes_sectors - set max sectors for a single
200 : * write zeroes
201 : * @q: the request queue for the device
202 : * @max_write_zeroes_sectors: maximum number of sectors to write per command
203 : **/
204 0 : void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
205 : unsigned int max_write_zeroes_sectors)
206 : {
207 0 : q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
208 0 : }
209 : EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors);
210 :
211 : /**
212 : * blk_queue_max_zone_append_sectors - set max sectors for a single zone append
213 : * @q: the request queue for the device
214 : * @max_zone_append_sectors: maximum number of sectors to write per command
215 : **/
216 0 : void blk_queue_max_zone_append_sectors(struct request_queue *q,
217 : unsigned int max_zone_append_sectors)
218 : {
219 : unsigned int max_sectors;
220 :
221 0 : if (WARN_ON(!blk_queue_is_zoned(q)))
222 : return;
223 :
224 : max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors);
225 : max_sectors = min(q->limits.chunk_sectors, max_sectors);
226 :
227 : /*
228 : * Signal eventual driver bugs resulting in the max_zone_append sectors limit
229 : * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set,
230 : * or the max_hw_sectors limit not set.
231 : */
232 : WARN_ON(!max_sectors);
233 :
234 : q->limits.max_zone_append_sectors = max_sectors;
235 : }
236 : EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors);
237 :
238 : /**
239 : * blk_queue_max_segments - set max hw segments for a request for this queue
240 : * @q: the request queue for the device
241 : * @max_segments: max number of segments
242 : *
243 : * Description:
244 : * Enables a low level driver to set an upper limit on the number of
245 : * hw data segments in a request.
246 : **/
247 0 : void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
248 : {
249 0 : if (!max_segments) {
250 0 : max_segments = 1;
251 0 : printk(KERN_INFO "%s: set to minimum %d\n",
252 : __func__, max_segments);
253 : }
254 :
255 0 : q->limits.max_segments = max_segments;
256 0 : }
257 : EXPORT_SYMBOL(blk_queue_max_segments);
258 :
259 : /**
260 : * blk_queue_max_discard_segments - set max segments for discard requests
261 : * @q: the request queue for the device
262 : * @max_segments: max number of segments
263 : *
264 : * Description:
265 : * Enables a low level driver to set an upper limit on the number of
266 : * segments in a discard request.
267 : **/
268 0 : void blk_queue_max_discard_segments(struct request_queue *q,
269 : unsigned short max_segments)
270 : {
271 0 : q->limits.max_discard_segments = max_segments;
272 0 : }
273 : EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
274 :
275 : /**
276 : * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
277 : * @q: the request queue for the device
278 : * @max_size: max size of segment in bytes
279 : *
280 : * Description:
281 : * Enables a low level driver to set an upper limit on the size of a
282 : * coalesced segment
283 : **/
284 0 : void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
285 : {
286 0 : if (max_size < PAGE_SIZE) {
287 0 : max_size = PAGE_SIZE;
288 0 : printk(KERN_INFO "%s: set to minimum %d\n",
289 : __func__, max_size);
290 : }
291 :
292 : /* see blk_queue_virt_boundary() for the explanation */
293 0 : WARN_ON_ONCE(q->limits.virt_boundary_mask);
294 :
295 0 : q->limits.max_segment_size = max_size;
296 0 : }
297 : EXPORT_SYMBOL(blk_queue_max_segment_size);
298 :
299 : /**
300 : * blk_queue_logical_block_size - set logical block size for the queue
301 : * @q: the request queue for the device
302 : * @size: the logical block size, in bytes
303 : *
304 : * Description:
305 : * This should be set to the lowest possible block size that the
306 : * storage device can address. The default of 512 covers most
307 : * hardware.
308 : **/
309 0 : void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
310 : {
311 0 : struct queue_limits *limits = &q->limits;
312 :
313 0 : limits->logical_block_size = size;
314 :
315 0 : if (limits->physical_block_size < size)
316 0 : limits->physical_block_size = size;
317 :
318 0 : if (limits->io_min < limits->physical_block_size)
319 0 : limits->io_min = limits->physical_block_size;
320 :
321 0 : limits->max_hw_sectors =
322 0 : round_down(limits->max_hw_sectors, size >> SECTOR_SHIFT);
323 0 : limits->max_sectors =
324 0 : round_down(limits->max_sectors, size >> SECTOR_SHIFT);
325 0 : }
326 : EXPORT_SYMBOL(blk_queue_logical_block_size);
327 :
328 : /**
329 : * blk_queue_physical_block_size - set physical block size for the queue
330 : * @q: the request queue for the device
331 : * @size: the physical block size, in bytes
332 : *
333 : * Description:
334 : * This should be set to the lowest possible sector size that the
335 : * hardware can operate on without reverting to read-modify-write
336 : * operations.
337 : */
338 0 : void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
339 : {
340 0 : q->limits.physical_block_size = size;
341 :
342 0 : if (q->limits.physical_block_size < q->limits.logical_block_size)
343 0 : q->limits.physical_block_size = q->limits.logical_block_size;
344 :
345 0 : if (q->limits.io_min < q->limits.physical_block_size)
346 0 : q->limits.io_min = q->limits.physical_block_size;
347 0 : }
348 : EXPORT_SYMBOL(blk_queue_physical_block_size);
349 :
350 : /**
351 : * blk_queue_zone_write_granularity - set zone write granularity for the queue
352 : * @q: the request queue for the zoned device
353 : * @size: the zone write granularity size, in bytes
354 : *
355 : * Description:
356 : * This should be set to the lowest possible size allowing to write in
357 : * sequential zones of a zoned block device.
358 : */
359 0 : void blk_queue_zone_write_granularity(struct request_queue *q,
360 : unsigned int size)
361 : {
362 0 : if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
363 : return;
364 :
365 : q->limits.zone_write_granularity = size;
366 :
367 : if (q->limits.zone_write_granularity < q->limits.logical_block_size)
368 : q->limits.zone_write_granularity = q->limits.logical_block_size;
369 : }
370 : EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity);
371 :
372 : /**
373 : * blk_queue_alignment_offset - set physical block alignment offset
374 : * @q: the request queue for the device
375 : * @offset: alignment offset in bytes
376 : *
377 : * Description:
378 : * Some devices are naturally misaligned to compensate for things like
379 : * the legacy DOS partition table 63-sector offset. Low-level drivers
380 : * should call this function for devices whose first sector is not
381 : * naturally aligned.
382 : */
383 0 : void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
384 : {
385 0 : q->limits.alignment_offset =
386 0 : offset & (q->limits.physical_block_size - 1);
387 0 : q->limits.misaligned = 0;
388 0 : }
389 : EXPORT_SYMBOL(blk_queue_alignment_offset);
390 :
391 0 : void disk_update_readahead(struct gendisk *disk)
392 : {
393 0 : struct request_queue *q = disk->queue;
394 :
395 : /*
396 : * For read-ahead of large files to be effective, we need to read ahead
397 : * at least twice the optimal I/O size.
398 : */
399 0 : disk->bdi->ra_pages =
400 0 : max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
401 0 : disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9);
402 0 : }
403 : EXPORT_SYMBOL_GPL(disk_update_readahead);
404 :
405 : /**
406 : * blk_limits_io_min - set minimum request size for a device
407 : * @limits: the queue limits
408 : * @min: smallest I/O size in bytes
409 : *
410 : * Description:
411 : * Some devices have an internal block size bigger than the reported
412 : * hardware sector size. This function can be used to signal the
413 : * smallest I/O the device can perform without incurring a performance
414 : * penalty.
415 : */
416 0 : void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
417 : {
418 0 : limits->io_min = min;
419 :
420 0 : if (limits->io_min < limits->logical_block_size)
421 0 : limits->io_min = limits->logical_block_size;
422 :
423 0 : if (limits->io_min < limits->physical_block_size)
424 0 : limits->io_min = limits->physical_block_size;
425 0 : }
426 : EXPORT_SYMBOL(blk_limits_io_min);
427 :
428 : /**
429 : * blk_queue_io_min - set minimum request size for the queue
430 : * @q: the request queue for the device
431 : * @min: smallest I/O size in bytes
432 : *
433 : * Description:
434 : * Storage devices may report a granularity or preferred minimum I/O
435 : * size which is the smallest request the device can perform without
436 : * incurring a performance penalty. For disk drives this is often the
437 : * physical block size. For RAID arrays it is often the stripe chunk
438 : * size. A properly aligned multiple of minimum_io_size is the
439 : * preferred request size for workloads where a high number of I/O
440 : * operations is desired.
441 : */
442 0 : void blk_queue_io_min(struct request_queue *q, unsigned int min)
443 : {
444 0 : blk_limits_io_min(&q->limits, min);
445 0 : }
446 : EXPORT_SYMBOL(blk_queue_io_min);
447 :
448 : /**
449 : * blk_limits_io_opt - set optimal request size for a device
450 : * @limits: the queue limits
451 : * @opt: smallest I/O size in bytes
452 : *
453 : * Description:
454 : * Storage devices may report an optimal I/O size, which is the
455 : * device's preferred unit for sustained I/O. This is rarely reported
456 : * for disk drives. For RAID arrays it is usually the stripe width or
457 : * the internal track size. A properly aligned multiple of
458 : * optimal_io_size is the preferred request size for workloads where
459 : * sustained throughput is desired.
460 : */
461 0 : void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
462 : {
463 0 : limits->io_opt = opt;
464 0 : }
465 : EXPORT_SYMBOL(blk_limits_io_opt);
466 :
467 : /**
468 : * blk_queue_io_opt - set optimal request size for the queue
469 : * @q: the request queue for the device
470 : * @opt: optimal request size in bytes
471 : *
472 : * Description:
473 : * Storage devices may report an optimal I/O size, which is the
474 : * device's preferred unit for sustained I/O. This is rarely reported
475 : * for disk drives. For RAID arrays it is usually the stripe width or
476 : * the internal track size. A properly aligned multiple of
477 : * optimal_io_size is the preferred request size for workloads where
478 : * sustained throughput is desired.
479 : */
480 0 : void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
481 : {
482 0 : blk_limits_io_opt(&q->limits, opt);
483 0 : if (!q->disk)
484 : return;
485 0 : q->disk->bdi->ra_pages =
486 0 : max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
487 : }
488 : EXPORT_SYMBOL(blk_queue_io_opt);
489 :
490 : static int queue_limit_alignment_offset(const struct queue_limits *lim,
491 : sector_t sector)
492 : {
493 0 : unsigned int granularity = max(lim->physical_block_size, lim->io_min);
494 0 : unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
495 : << SECTOR_SHIFT;
496 :
497 0 : return (granularity + lim->alignment_offset - alignment) % granularity;
498 : }
499 :
500 : static unsigned int queue_limit_discard_alignment(
501 : const struct queue_limits *lim, sector_t sector)
502 : {
503 : unsigned int alignment, granularity, offset;
504 :
505 0 : if (!lim->max_discard_sectors)
506 : return 0;
507 :
508 : /* Why are these in bytes, not sectors? */
509 0 : alignment = lim->discard_alignment >> SECTOR_SHIFT;
510 0 : granularity = lim->discard_granularity >> SECTOR_SHIFT;
511 0 : if (!granularity)
512 : return 0;
513 :
514 : /* Offset of the partition start in 'granularity' sectors */
515 0 : offset = sector_div(sector, granularity);
516 :
517 : /* And why do we do this modulus *again* in blkdev_issue_discard()? */
518 0 : offset = (granularity + alignment - offset) % granularity;
519 :
520 : /* Turn it back into bytes, gaah */
521 0 : return offset << SECTOR_SHIFT;
522 : }
523 :
524 : static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
525 : {
526 0 : sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
527 0 : if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
528 0 : sectors = PAGE_SIZE >> SECTOR_SHIFT;
529 : return sectors;
530 : }
531 :
532 : /**
533 : * blk_stack_limits - adjust queue_limits for stacked devices
534 : * @t: the stacking driver limits (top device)
535 : * @b: the underlying queue limits (bottom, component device)
536 : * @start: first data sector within component device
537 : *
538 : * Description:
539 : * This function is used by stacking drivers like MD and DM to ensure
540 : * that all component devices have compatible block sizes and
541 : * alignments. The stacking driver must provide a queue_limits
542 : * struct (top) and then iteratively call the stacking function for
543 : * all component (bottom) devices. The stacking function will
544 : * attempt to combine the values and ensure proper alignment.
545 : *
546 : * Returns 0 if the top and bottom queue_limits are compatible. The
547 : * top device's block sizes and alignment offsets may be adjusted to
548 : * ensure alignment with the bottom device. If no compatible sizes
549 : * and alignments exist, -1 is returned and the resulting top
550 : * queue_limits will have the misaligned flag set to indicate that
551 : * the alignment_offset is undefined.
552 : */
553 0 : int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
554 : sector_t start)
555 : {
556 0 : unsigned int top, bottom, alignment, ret = 0;
557 :
558 0 : t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
559 0 : t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
560 0 : t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
561 0 : t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
562 : b->max_write_zeroes_sectors);
563 0 : t->max_zone_append_sectors = min(t->max_zone_append_sectors,
564 : b->max_zone_append_sectors);
565 0 : t->bounce = max(t->bounce, b->bounce);
566 :
567 0 : t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
568 : b->seg_boundary_mask);
569 0 : t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
570 : b->virt_boundary_mask);
571 :
572 0 : t->max_segments = min_not_zero(t->max_segments, b->max_segments);
573 0 : t->max_discard_segments = min_not_zero(t->max_discard_segments,
574 : b->max_discard_segments);
575 0 : t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
576 : b->max_integrity_segments);
577 :
578 0 : t->max_segment_size = min_not_zero(t->max_segment_size,
579 : b->max_segment_size);
580 :
581 0 : t->misaligned |= b->misaligned;
582 :
583 0 : alignment = queue_limit_alignment_offset(b, start);
584 :
585 : /* Bottom device has different alignment. Check that it is
586 : * compatible with the current top alignment.
587 : */
588 0 : if (t->alignment_offset != alignment) {
589 :
590 0 : top = max(t->physical_block_size, t->io_min)
591 : + t->alignment_offset;
592 0 : bottom = max(b->physical_block_size, b->io_min) + alignment;
593 :
594 : /* Verify that top and bottom intervals line up */
595 0 : if (max(top, bottom) % min(top, bottom)) {
596 0 : t->misaligned = 1;
597 0 : ret = -1;
598 : }
599 : }
600 :
601 0 : t->logical_block_size = max(t->logical_block_size,
602 : b->logical_block_size);
603 :
604 0 : t->physical_block_size = max(t->physical_block_size,
605 : b->physical_block_size);
606 :
607 0 : t->io_min = max(t->io_min, b->io_min);
608 0 : t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
609 0 : t->dma_alignment = max(t->dma_alignment, b->dma_alignment);
610 :
611 : /* Set non-power-of-2 compatible chunk_sectors boundary */
612 0 : if (b->chunk_sectors)
613 0 : t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
614 :
615 : /* Physical block size a multiple of the logical block size? */
616 0 : if (t->physical_block_size & (t->logical_block_size - 1)) {
617 0 : t->physical_block_size = t->logical_block_size;
618 0 : t->misaligned = 1;
619 0 : ret = -1;
620 : }
621 :
622 : /* Minimum I/O a multiple of the physical block size? */
623 0 : if (t->io_min & (t->physical_block_size - 1)) {
624 0 : t->io_min = t->physical_block_size;
625 0 : t->misaligned = 1;
626 0 : ret = -1;
627 : }
628 :
629 : /* Optimal I/O a multiple of the physical block size? */
630 0 : if (t->io_opt & (t->physical_block_size - 1)) {
631 0 : t->io_opt = 0;
632 0 : t->misaligned = 1;
633 0 : ret = -1;
634 : }
635 :
636 : /* chunk_sectors a multiple of the physical block size? */
637 0 : if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
638 0 : t->chunk_sectors = 0;
639 0 : t->misaligned = 1;
640 0 : ret = -1;
641 : }
642 :
643 0 : t->raid_partial_stripes_expensive =
644 0 : max(t->raid_partial_stripes_expensive,
645 : b->raid_partial_stripes_expensive);
646 :
647 : /* Find lowest common alignment_offset */
648 0 : t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
649 0 : % max(t->physical_block_size, t->io_min);
650 :
651 : /* Verify that new alignment_offset is on a logical block boundary */
652 0 : if (t->alignment_offset & (t->logical_block_size - 1)) {
653 0 : t->misaligned = 1;
654 0 : ret = -1;
655 : }
656 :
657 0 : t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
658 0 : t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
659 0 : t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
660 :
661 : /* Discard alignment and granularity */
662 0 : if (b->discard_granularity) {
663 0 : alignment = queue_limit_discard_alignment(b, start);
664 :
665 0 : if (t->discard_granularity != 0 &&
666 0 : t->discard_alignment != alignment) {
667 0 : top = t->discard_granularity + t->discard_alignment;
668 0 : bottom = b->discard_granularity + alignment;
669 :
670 : /* Verify that top and bottom intervals line up */
671 0 : if ((max(top, bottom) % min(top, bottom)) != 0)
672 0 : t->discard_misaligned = 1;
673 : }
674 :
675 0 : t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
676 : b->max_discard_sectors);
677 0 : t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
678 : b->max_hw_discard_sectors);
679 0 : t->discard_granularity = max(t->discard_granularity,
680 : b->discard_granularity);
681 0 : t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
682 0 : t->discard_granularity;
683 : }
684 0 : t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors,
685 : b->max_secure_erase_sectors);
686 0 : t->zone_write_granularity = max(t->zone_write_granularity,
687 : b->zone_write_granularity);
688 0 : t->zoned = max(t->zoned, b->zoned);
689 0 : return ret;
690 : }
691 : EXPORT_SYMBOL(blk_stack_limits);
692 :
693 : /**
694 : * disk_stack_limits - adjust queue limits for stacked drivers
695 : * @disk: MD/DM gendisk (top)
696 : * @bdev: the underlying block device (bottom)
697 : * @offset: offset to beginning of data within component device
698 : *
699 : * Description:
700 : * Merges the limits for a top level gendisk and a bottom level
701 : * block_device.
702 : */
703 0 : void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
704 : sector_t offset)
705 : {
706 0 : struct request_queue *t = disk->queue;
707 :
708 0 : if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
709 0 : get_start_sect(bdev) + (offset >> 9)) < 0)
710 0 : pr_notice("%s: Warning: Device %pg is misaligned\n",
711 : disk->disk_name, bdev);
712 :
713 0 : disk_update_readahead(disk);
714 0 : }
715 : EXPORT_SYMBOL(disk_stack_limits);
716 :
717 : /**
718 : * blk_queue_update_dma_pad - update pad mask
719 : * @q: the request queue for the device
720 : * @mask: pad mask
721 : *
722 : * Update dma pad mask.
723 : *
724 : * Appending pad buffer to a request modifies the last entry of a
725 : * scatter list such that it includes the pad buffer.
726 : **/
727 0 : void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
728 : {
729 0 : if (mask > q->dma_pad_mask)
730 0 : q->dma_pad_mask = mask;
731 0 : }
732 : EXPORT_SYMBOL(blk_queue_update_dma_pad);
733 :
734 : /**
735 : * blk_queue_segment_boundary - set boundary rules for segment merging
736 : * @q: the request queue for the device
737 : * @mask: the memory boundary mask
738 : **/
739 0 : void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
740 : {
741 0 : if (mask < PAGE_SIZE - 1) {
742 0 : mask = PAGE_SIZE - 1;
743 0 : printk(KERN_INFO "%s: set to minimum %lx\n",
744 : __func__, mask);
745 : }
746 :
747 0 : q->limits.seg_boundary_mask = mask;
748 0 : }
749 : EXPORT_SYMBOL(blk_queue_segment_boundary);
750 :
751 : /**
752 : * blk_queue_virt_boundary - set boundary rules for bio merging
753 : * @q: the request queue for the device
754 : * @mask: the memory boundary mask
755 : **/
756 0 : void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
757 : {
758 0 : q->limits.virt_boundary_mask = mask;
759 :
760 : /*
761 : * Devices that require a virtual boundary do not support scatter/gather
762 : * I/O natively, but instead require a descriptor list entry for each
763 : * page (which might not be idential to the Linux PAGE_SIZE). Because
764 : * of that they are not limited by our notion of "segment size".
765 : */
766 0 : if (mask)
767 0 : q->limits.max_segment_size = UINT_MAX;
768 0 : }
769 : EXPORT_SYMBOL(blk_queue_virt_boundary);
770 :
771 : /**
772 : * blk_queue_dma_alignment - set dma length and memory alignment
773 : * @q: the request queue for the device
774 : * @mask: alignment mask
775 : *
776 : * description:
777 : * set required memory and length alignment for direct dma transactions.
778 : * this is used when building direct io requests for the queue.
779 : *
780 : **/
781 0 : void blk_queue_dma_alignment(struct request_queue *q, int mask)
782 : {
783 0 : q->limits.dma_alignment = mask;
784 0 : }
785 : EXPORT_SYMBOL(blk_queue_dma_alignment);
786 :
787 : /**
788 : * blk_queue_update_dma_alignment - update dma length and memory alignment
789 : * @q: the request queue for the device
790 : * @mask: alignment mask
791 : *
792 : * description:
793 : * update required memory and length alignment for direct dma transactions.
794 : * If the requested alignment is larger than the current alignment, then
795 : * the current queue alignment is updated to the new value, otherwise it
796 : * is left alone. The design of this is to allow multiple objects
797 : * (driver, device, transport etc) to set their respective
798 : * alignments without having them interfere.
799 : *
800 : **/
801 0 : void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
802 : {
803 0 : BUG_ON(mask > PAGE_SIZE);
804 :
805 0 : if (mask > q->limits.dma_alignment)
806 0 : q->limits.dma_alignment = mask;
807 0 : }
808 : EXPORT_SYMBOL(blk_queue_update_dma_alignment);
809 :
810 : /**
811 : * blk_set_queue_depth - tell the block layer about the device queue depth
812 : * @q: the request queue for the device
813 : * @depth: queue depth
814 : *
815 : */
816 0 : void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
817 : {
818 0 : q->queue_depth = depth;
819 0 : rq_qos_queue_depth_changed(q);
820 0 : }
821 : EXPORT_SYMBOL(blk_set_queue_depth);
822 :
823 : /**
824 : * blk_queue_write_cache - configure queue's write cache
825 : * @q: the request queue for the device
826 : * @wc: write back cache on or off
827 : * @fua: device supports FUA writes, if true
828 : *
829 : * Tell the block layer about the write cache of @q.
830 : */
831 0 : void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
832 : {
833 0 : if (wc)
834 0 : blk_queue_flag_set(QUEUE_FLAG_WC, q);
835 : else
836 0 : blk_queue_flag_clear(QUEUE_FLAG_WC, q);
837 0 : if (fua)
838 0 : blk_queue_flag_set(QUEUE_FLAG_FUA, q);
839 : else
840 0 : blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
841 :
842 0 : wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
843 0 : }
844 : EXPORT_SYMBOL_GPL(blk_queue_write_cache);
845 :
846 : /**
847 : * blk_queue_required_elevator_features - Set a queue required elevator features
848 : * @q: the request queue for the target device
849 : * @features: Required elevator features OR'ed together
850 : *
851 : * Tell the block layer that for the device controlled through @q, only the
852 : * only elevators that can be used are those that implement at least the set of
853 : * features specified by @features.
854 : */
855 0 : void blk_queue_required_elevator_features(struct request_queue *q,
856 : unsigned int features)
857 : {
858 0 : q->required_elevator_features = features;
859 0 : }
860 : EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features);
861 :
862 : /**
863 : * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
864 : * @q: the request queue for the device
865 : * @dev: the device pointer for dma
866 : *
867 : * Tell the block layer about merging the segments by dma map of @q.
868 : */
869 0 : bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
870 : struct device *dev)
871 : {
872 0 : unsigned long boundary = dma_get_merge_boundary(dev);
873 :
874 0 : if (!boundary)
875 : return false;
876 :
877 : /* No need to update max_segment_size. see blk_queue_virt_boundary() */
878 0 : blk_queue_virt_boundary(q, boundary);
879 :
880 0 : return true;
881 : }
882 : EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
883 :
884 : static bool disk_has_partitions(struct gendisk *disk)
885 : {
886 : unsigned long idx;
887 : struct block_device *part;
888 : bool ret = false;
889 :
890 : rcu_read_lock();
891 : xa_for_each(&disk->part_tbl, idx, part) {
892 : if (bdev_is_partition(part)) {
893 : ret = true;
894 : break;
895 : }
896 : }
897 : rcu_read_unlock();
898 :
899 : return ret;
900 : }
901 :
902 : /**
903 : * disk_set_zoned - configure the zoned model for a disk
904 : * @disk: the gendisk of the queue to configure
905 : * @model: the zoned model to set
906 : *
907 : * Set the zoned model of @disk to @model.
908 : *
909 : * When @model is BLK_ZONED_HM (host managed), this should be called only
910 : * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option).
911 : * If @model specifies BLK_ZONED_HA (host aware), the effective model used
912 : * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions
913 : * on the disk.
914 : */
915 0 : void disk_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
916 : {
917 0 : struct request_queue *q = disk->queue;
918 :
919 0 : switch (model) {
920 : case BLK_ZONED_HM:
921 : /*
922 : * Host managed devices are supported only if
923 : * CONFIG_BLK_DEV_ZONED is enabled.
924 : */
925 0 : WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));
926 : break;
927 : case BLK_ZONED_HA:
928 : /*
929 : * Host aware devices can be treated either as regular block
930 : * devices (similar to drive managed devices) or as zoned block
931 : * devices to take advantage of the zone command set, similarly
932 : * to host managed devices. We try the latter if there are no
933 : * partitions and zoned block device support is enabled, else
934 : * we do nothing special as far as the block layer is concerned.
935 : */
936 : if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||
937 : disk_has_partitions(disk))
938 : model = BLK_ZONED_NONE;
939 : break;
940 : case BLK_ZONED_NONE:
941 : default:
942 0 : if (WARN_ON_ONCE(model != BLK_ZONED_NONE))
943 0 : model = BLK_ZONED_NONE;
944 : break;
945 : }
946 :
947 0 : q->limits.zoned = model;
948 0 : if (model != BLK_ZONED_NONE) {
949 : /*
950 : * Set the zone write granularity to the device logical block
951 : * size by default. The driver can change this value if needed.
952 : */
953 0 : blk_queue_zone_write_granularity(q,
954 : queue_logical_block_size(q));
955 : } else {
956 : disk_clear_zone_settings(disk);
957 : }
958 0 : }
959 : EXPORT_SYMBOL_GPL(disk_set_zoned);
960 :
961 0 : int bdev_alignment_offset(struct block_device *bdev)
962 : {
963 0 : struct request_queue *q = bdev_get_queue(bdev);
964 :
965 0 : if (q->limits.misaligned)
966 : return -1;
967 0 : if (bdev_is_partition(bdev))
968 0 : return queue_limit_alignment_offset(&q->limits,
969 : bdev->bd_start_sect);
970 0 : return q->limits.alignment_offset;
971 : }
972 : EXPORT_SYMBOL_GPL(bdev_alignment_offset);
973 :
974 0 : unsigned int bdev_discard_alignment(struct block_device *bdev)
975 : {
976 0 : struct request_queue *q = bdev_get_queue(bdev);
977 :
978 0 : if (bdev_is_partition(bdev))
979 0 : return queue_limit_discard_alignment(&q->limits,
980 : bdev->bd_start_sect);
981 0 : return q->limits.discard_alignment;
982 : }
983 : EXPORT_SYMBOL_GPL(bdev_discard_alignment);
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