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 
blk_queue_rq_timeout(struct request_queue * q,unsigned int timeout)22 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
23 {
24 	q->rq_timeout = timeout;
25 }
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  */
blk_set_default_limits(struct queue_limits * lim)35 void blk_set_default_limits(struct queue_limits *lim)
36 {
37 	lim->max_segments = BLK_MAX_SEGMENTS;
38 	lim->max_discard_segments = 1;
39 	lim->max_integrity_segments = 0;
40 	lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
41 	lim->virt_boundary_mask = 0;
42 	lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
43 	lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
44 	lim->max_user_sectors = lim->max_dev_sectors = 0;
45 	lim->chunk_sectors = 0;
46 	lim->max_write_zeroes_sectors = 0;
47 	lim->max_zone_append_sectors = 0;
48 	lim->max_discard_sectors = 0;
49 	lim->max_hw_discard_sectors = 0;
50 	lim->max_secure_erase_sectors = 0;
51 	lim->discard_granularity = 0;
52 	lim->discard_alignment = 0;
53 	lim->discard_misaligned = 0;
54 	lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
55 	lim->bounce = BLK_BOUNCE_NONE;
56 	lim->alignment_offset = 0;
57 	lim->io_opt = 0;
58 	lim->misaligned = 0;
59 	lim->zoned = BLK_ZONED_NONE;
60 	lim->zone_write_granularity = 0;
61 	lim->dma_alignment = 511;
62 }
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  */
blk_set_stacking_limits(struct queue_limits * lim)72 void blk_set_stacking_limits(struct queue_limits *lim)
73 {
74 	blk_set_default_limits(lim);
75 
76 	/* Inherit limits from component devices */
77 	lim->max_segments = USHRT_MAX;
78 	lim->max_discard_segments = USHRT_MAX;
79 	lim->max_hw_sectors = UINT_MAX;
80 	lim->max_segment_size = UINT_MAX;
81 	lim->max_sectors = UINT_MAX;
82 	lim->max_dev_sectors = UINT_MAX;
83 	lim->max_write_zeroes_sectors = UINT_MAX;
84 	lim->max_zone_append_sectors = UINT_MAX;
85 }
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  **/
blk_queue_bounce_limit(struct request_queue * q,enum blk_bounce bounce)98 void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce bounce)
99 {
100 	q->limits.bounce = bounce;
101 }
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  **/
blk_queue_max_hw_sectors(struct request_queue * q,unsigned int max_hw_sectors)123 void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
124 {
125 	struct queue_limits *limits = &q->limits;
126 	unsigned int max_sectors;
127 
128 	if ((max_hw_sectors << 9) < PAGE_SIZE) {
129 		max_hw_sectors = 1 << (PAGE_SHIFT - 9);
130 		printk(KERN_INFO "%s: set to minimum %d\n",
131 		       __func__, max_hw_sectors);
132 	}
133 
134 	max_hw_sectors = round_down(max_hw_sectors,
135 				    limits->logical_block_size >> SECTOR_SHIFT);
136 	limits->max_hw_sectors = max_hw_sectors;
137 
138 	max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
139 
140 	if (limits->max_user_sectors)
141 		max_sectors = min(max_sectors, limits->max_user_sectors);
142 	else
143 		max_sectors = min(max_sectors, BLK_DEF_MAX_SECTORS);
144 
145 	max_sectors = round_down(max_sectors,
146 				 limits->logical_block_size >> SECTOR_SHIFT);
147 	limits->max_sectors = max_sectors;
148 
149 	if (!q->disk)
150 		return;
151 	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  **/
blk_queue_chunk_sectors(struct request_queue * q,unsigned int chunk_sectors)167 void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
168 {
169 	q->limits.chunk_sectors = chunk_sectors;
170 }
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  **/
blk_queue_max_discard_sectors(struct request_queue * q,unsigned int max_discard_sectors)178 void blk_queue_max_discard_sectors(struct request_queue *q,
179 		unsigned int max_discard_sectors)
180 {
181 	q->limits.max_hw_discard_sectors = max_discard_sectors;
182 	q->limits.max_discard_sectors = max_discard_sectors;
183 }
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  **/
blk_queue_max_secure_erase_sectors(struct request_queue * q,unsigned int max_sectors)191 void blk_queue_max_secure_erase_sectors(struct request_queue *q,
192 		unsigned int max_sectors)
193 {
194 	q->limits.max_secure_erase_sectors = max_sectors;
195 }
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  **/
blk_queue_max_write_zeroes_sectors(struct request_queue * q,unsigned int max_write_zeroes_sectors)204 void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
205 		unsigned int max_write_zeroes_sectors)
206 {
207 	q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
208 }
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  **/
blk_queue_max_zone_append_sectors(struct request_queue * q,unsigned int max_zone_append_sectors)216 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 	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  **/
blk_queue_max_segments(struct request_queue * q,unsigned short max_segments)247 void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
248 {
249 	if (!max_segments) {
250 		max_segments = 1;
251 		printk(KERN_INFO "%s: set to minimum %d\n",
252 		       __func__, max_segments);
253 	}
254 
255 	q->limits.max_segments = max_segments;
256 }
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  **/
blk_queue_max_discard_segments(struct request_queue * q,unsigned short max_segments)268 void blk_queue_max_discard_segments(struct request_queue *q,
269 		unsigned short max_segments)
270 {
271 	q->limits.max_discard_segments = max_segments;
272 }
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  **/
blk_queue_max_segment_size(struct request_queue * q,unsigned int max_size)284 void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
285 {
286 	if (max_size < PAGE_SIZE) {
287 		max_size = PAGE_SIZE;
288 		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 	WARN_ON_ONCE(q->limits.virt_boundary_mask);
294 
295 	q->limits.max_segment_size = max_size;
296 }
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  **/
blk_queue_logical_block_size(struct request_queue * q,unsigned int size)309 void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
310 {
311 	struct queue_limits *limits = &q->limits;
312 
313 	limits->logical_block_size = size;
314 
315 	if (limits->physical_block_size < size)
316 		limits->physical_block_size = size;
317 
318 	if (limits->io_min < limits->physical_block_size)
319 		limits->io_min = limits->physical_block_size;
320 
321 	limits->max_hw_sectors =
322 		round_down(limits->max_hw_sectors, size >> SECTOR_SHIFT);
323 	limits->max_sectors =
324 		round_down(limits->max_sectors, size >> SECTOR_SHIFT);
325 }
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  */
blk_queue_physical_block_size(struct request_queue * q,unsigned int size)338 void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
339 {
340 	q->limits.physical_block_size = size;
341 
342 	if (q->limits.physical_block_size < q->limits.logical_block_size)
343 		q->limits.physical_block_size = q->limits.logical_block_size;
344 
345 	if (q->limits.io_min < q->limits.physical_block_size)
346 		q->limits.io_min = q->limits.physical_block_size;
347 }
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  */
blk_queue_zone_write_granularity(struct request_queue * q,unsigned int size)359 void blk_queue_zone_write_granularity(struct request_queue *q,
360 				      unsigned int size)
361 {
362 	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  */
blk_queue_alignment_offset(struct request_queue * q,unsigned int offset)383 void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
384 {
385 	q->limits.alignment_offset =
386 		offset & (q->limits.physical_block_size - 1);
387 	q->limits.misaligned = 0;
388 }
389 EXPORT_SYMBOL(blk_queue_alignment_offset);
390 
disk_update_readahead(struct gendisk * disk)391 void disk_update_readahead(struct gendisk *disk)
392 {
393 	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 	disk->bdi->ra_pages =
400 		max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
401 	disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9);
402 }
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  */
blk_limits_io_min(struct queue_limits * limits,unsigned int min)416 void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
417 {
418 	limits->io_min = min;
419 
420 	if (limits->io_min < limits->logical_block_size)
421 		limits->io_min = limits->logical_block_size;
422 
423 	if (limits->io_min < limits->physical_block_size)
424 		limits->io_min = limits->physical_block_size;
425 }
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  */
blk_queue_io_min(struct request_queue * q,unsigned int min)442 void blk_queue_io_min(struct request_queue *q, unsigned int min)
443 {
444 	blk_limits_io_min(&q->limits, min);
445 }
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  */
blk_limits_io_opt(struct queue_limits * limits,unsigned int opt)461 void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
462 {
463 	limits->io_opt = opt;
464 }
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  */
blk_queue_io_opt(struct request_queue * q,unsigned int opt)480 void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
481 {
482 	blk_limits_io_opt(&q->limits, opt);
483 	if (!q->disk)
484 		return;
485 	q->disk->bdi->ra_pages =
486 		max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
487 }
488 EXPORT_SYMBOL(blk_queue_io_opt);
489 
queue_limit_alignment_offset(const struct queue_limits * lim,sector_t sector)490 static int queue_limit_alignment_offset(const struct queue_limits *lim,
491 		sector_t sector)
492 {
493 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
494 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
495 		<< SECTOR_SHIFT;
496 
497 	return (granularity + lim->alignment_offset - alignment) % granularity;
498 }
499 
queue_limit_discard_alignment(const struct queue_limits * lim,sector_t sector)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 	if (!lim->max_discard_sectors)
506 		return 0;
507 
508 	/* Why are these in bytes, not sectors? */
509 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
510 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
511 	if (!granularity)
512 		return 0;
513 
514 	/* Offset of the partition start in 'granularity' sectors */
515 	offset = sector_div(sector, granularity);
516 
517 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
518 	offset = (granularity + alignment - offset) % granularity;
519 
520 	/* Turn it back into bytes, gaah */
521 	return offset << SECTOR_SHIFT;
522 }
523 
blk_round_down_sectors(unsigned int sectors,unsigned int lbs)524 static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
525 {
526 	sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
527 	if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
528 		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  */
blk_stack_limits(struct queue_limits * t,struct queue_limits * b,sector_t start)553 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
554 		     sector_t start)
555 {
556 	unsigned int top, bottom, alignment, ret = 0;
557 
558 	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
559 	t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
560 	t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
561 	t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
562 					b->max_write_zeroes_sectors);
563 	t->max_zone_append_sectors = min(t->max_zone_append_sectors,
564 					b->max_zone_append_sectors);
565 	t->bounce = max(t->bounce, b->bounce);
566 
567 	t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
568 					    b->seg_boundary_mask);
569 	t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
570 					    b->virt_boundary_mask);
571 
572 	t->max_segments = min_not_zero(t->max_segments, b->max_segments);
573 	t->max_discard_segments = min_not_zero(t->max_discard_segments,
574 					       b->max_discard_segments);
575 	t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
576 						 b->max_integrity_segments);
577 
578 	t->max_segment_size = min_not_zero(t->max_segment_size,
579 					   b->max_segment_size);
580 
581 	t->misaligned |= b->misaligned;
582 
583 	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 	if (t->alignment_offset != alignment) {
589 
590 		top = max(t->physical_block_size, t->io_min)
591 			+ t->alignment_offset;
592 		bottom = max(b->physical_block_size, b->io_min) + alignment;
593 
594 		/* Verify that top and bottom intervals line up */
595 		if (max(top, bottom) % min(top, bottom)) {
596 			t->misaligned = 1;
597 			ret = -1;
598 		}
599 	}
600 
601 	t->logical_block_size = max(t->logical_block_size,
602 				    b->logical_block_size);
603 
604 	t->physical_block_size = max(t->physical_block_size,
605 				     b->physical_block_size);
606 
607 	t->io_min = max(t->io_min, b->io_min);
608 	t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
609 	t->dma_alignment = max(t->dma_alignment, b->dma_alignment);
610 
611 	/* Set non-power-of-2 compatible chunk_sectors boundary */
612 	if (b->chunk_sectors)
613 		t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
614 
615 	/* Physical block size a multiple of the logical block size? */
616 	if (t->physical_block_size & (t->logical_block_size - 1)) {
617 		t->physical_block_size = t->logical_block_size;
618 		t->misaligned = 1;
619 		ret = -1;
620 	}
621 
622 	/* Minimum I/O a multiple of the physical block size? */
623 	if (t->io_min & (t->physical_block_size - 1)) {
624 		t->io_min = t->physical_block_size;
625 		t->misaligned = 1;
626 		ret = -1;
627 	}
628 
629 	/* Optimal I/O a multiple of the physical block size? */
630 	if (t->io_opt & (t->physical_block_size - 1)) {
631 		t->io_opt = 0;
632 		t->misaligned = 1;
633 		ret = -1;
634 	}
635 
636 	/* chunk_sectors a multiple of the physical block size? */
637 	if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
638 		t->chunk_sectors = 0;
639 		t->misaligned = 1;
640 		ret = -1;
641 	}
642 
643 	t->raid_partial_stripes_expensive =
644 		max(t->raid_partial_stripes_expensive,
645 		    b->raid_partial_stripes_expensive);
646 
647 	/* Find lowest common alignment_offset */
648 	t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
649 		% max(t->physical_block_size, t->io_min);
650 
651 	/* Verify that new alignment_offset is on a logical block boundary */
652 	if (t->alignment_offset & (t->logical_block_size - 1)) {
653 		t->misaligned = 1;
654 		ret = -1;
655 	}
656 
657 	t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
658 	t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
659 	t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
660 
661 	/* Discard alignment and granularity */
662 	if (b->discard_granularity) {
663 		alignment = queue_limit_discard_alignment(b, start);
664 
665 		if (t->discard_granularity != 0 &&
666 		    t->discard_alignment != alignment) {
667 			top = t->discard_granularity + t->discard_alignment;
668 			bottom = b->discard_granularity + alignment;
669 
670 			/* Verify that top and bottom intervals line up */
671 			if ((max(top, bottom) % min(top, bottom)) != 0)
672 				t->discard_misaligned = 1;
673 		}
674 
675 		t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
676 						      b->max_discard_sectors);
677 		t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
678 							 b->max_hw_discard_sectors);
679 		t->discard_granularity = max(t->discard_granularity,
680 					     b->discard_granularity);
681 		t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
682 			t->discard_granularity;
683 	}
684 	t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors,
685 						   b->max_secure_erase_sectors);
686 	t->zone_write_granularity = max(t->zone_write_granularity,
687 					b->zone_write_granularity);
688 	t->zoned = max(t->zoned, b->zoned);
689 	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  */
disk_stack_limits(struct gendisk * disk,struct block_device * bdev,sector_t offset)703 void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
704 		       sector_t offset)
705 {
706 	struct request_queue *t = disk->queue;
707 
708 	if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
709 			get_start_sect(bdev) + (offset >> 9)) < 0)
710 		pr_notice("%s: Warning: Device %pg is misaligned\n",
711 			disk->disk_name, bdev);
712 
713 	disk_update_readahead(disk);
714 }
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  **/
blk_queue_update_dma_pad(struct request_queue * q,unsigned int mask)727 void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
728 {
729 	if (mask > q->dma_pad_mask)
730 		q->dma_pad_mask = mask;
731 }
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  **/
blk_queue_segment_boundary(struct request_queue * q,unsigned long mask)739 void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
740 {
741 	if (mask < PAGE_SIZE - 1) {
742 		mask = PAGE_SIZE - 1;
743 		printk(KERN_INFO "%s: set to minimum %lx\n",
744 		       __func__, mask);
745 	}
746 
747 	q->limits.seg_boundary_mask = mask;
748 }
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  **/
blk_queue_virt_boundary(struct request_queue * q,unsigned long mask)756 void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
757 {
758 	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 	if (mask)
767 		q->limits.max_segment_size = UINT_MAX;
768 }
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  **/
blk_queue_dma_alignment(struct request_queue * q,int mask)781 void blk_queue_dma_alignment(struct request_queue *q, int mask)
782 {
783 	q->limits.dma_alignment = mask;
784 }
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  **/
blk_queue_update_dma_alignment(struct request_queue * q,int mask)801 void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
802 {
803 	BUG_ON(mask > PAGE_SIZE);
804 
805 	if (mask > q->limits.dma_alignment)
806 		q->limits.dma_alignment = mask;
807 }
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  */
blk_set_queue_depth(struct request_queue * q,unsigned int depth)816 void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
817 {
818 	q->queue_depth = depth;
819 	rq_qos_queue_depth_changed(q);
820 }
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  */
blk_queue_write_cache(struct request_queue * q,bool wc,bool fua)831 void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
832 {
833 	if (wc) {
834 		blk_queue_flag_set(QUEUE_FLAG_HW_WC, q);
835 		blk_queue_flag_set(QUEUE_FLAG_WC, q);
836 	} else {
837 		blk_queue_flag_clear(QUEUE_FLAG_HW_WC, q);
838 		blk_queue_flag_clear(QUEUE_FLAG_WC, q);
839 	}
840 	if (fua)
841 		blk_queue_flag_set(QUEUE_FLAG_FUA, q);
842 	else
843 		blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
844 
845 	wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
846 }
847 EXPORT_SYMBOL_GPL(blk_queue_write_cache);
848 
849 /**
850  * blk_queue_required_elevator_features - Set a queue required elevator features
851  * @q:		the request queue for the target device
852  * @features:	Required elevator features OR'ed together
853  *
854  * Tell the block layer that for the device controlled through @q, only the
855  * only elevators that can be used are those that implement at least the set of
856  * features specified by @features.
857  */
blk_queue_required_elevator_features(struct request_queue * q,unsigned int features)858 void blk_queue_required_elevator_features(struct request_queue *q,
859 					  unsigned int features)
860 {
861 	q->required_elevator_features = features;
862 }
863 EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features);
864 
865 /**
866  * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
867  * @q:		the request queue for the device
868  * @dev:	the device pointer for dma
869  *
870  * Tell the block layer about merging the segments by dma map of @q.
871  */
blk_queue_can_use_dma_map_merging(struct request_queue * q,struct device * dev)872 bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
873 				       struct device *dev)
874 {
875 	unsigned long boundary = dma_get_merge_boundary(dev);
876 
877 	if (!boundary)
878 		return false;
879 
880 	/* No need to update max_segment_size. see blk_queue_virt_boundary() */
881 	blk_queue_virt_boundary(q, boundary);
882 
883 	return true;
884 }
885 EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
886 
disk_has_partitions(struct gendisk * disk)887 static bool disk_has_partitions(struct gendisk *disk)
888 {
889 	unsigned long idx;
890 	struct block_device *part;
891 	bool ret = false;
892 
893 	rcu_read_lock();
894 	xa_for_each(&disk->part_tbl, idx, part) {
895 		if (bdev_is_partition(part)) {
896 			ret = true;
897 			break;
898 		}
899 	}
900 	rcu_read_unlock();
901 
902 	return ret;
903 }
904 
905 /**
906  * disk_set_zoned - configure the zoned model for a disk
907  * @disk:	the gendisk of the queue to configure
908  * @model:	the zoned model to set
909  *
910  * Set the zoned model of @disk to @model.
911  *
912  * When @model is BLK_ZONED_HM (host managed), this should be called only
913  * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option).
914  * If @model specifies BLK_ZONED_HA (host aware), the effective model used
915  * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions
916  * on the disk.
917  */
disk_set_zoned(struct gendisk * disk,enum blk_zoned_model model)918 void disk_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
919 {
920 	struct request_queue *q = disk->queue;
921 	unsigned int old_model = q->limits.zoned;
922 
923 	switch (model) {
924 	case BLK_ZONED_HM:
925 		/*
926 		 * Host managed devices are supported only if
927 		 * CONFIG_BLK_DEV_ZONED is enabled.
928 		 */
929 		WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));
930 		break;
931 	case BLK_ZONED_HA:
932 		/*
933 		 * Host aware devices can be treated either as regular block
934 		 * devices (similar to drive managed devices) or as zoned block
935 		 * devices to take advantage of the zone command set, similarly
936 		 * to host managed devices. We try the latter if there are no
937 		 * partitions and zoned block device support is enabled, else
938 		 * we do nothing special as far as the block layer is concerned.
939 		 */
940 		if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||
941 		    disk_has_partitions(disk))
942 			model = BLK_ZONED_NONE;
943 		break;
944 	case BLK_ZONED_NONE:
945 	default:
946 		if (WARN_ON_ONCE(model != BLK_ZONED_NONE))
947 			model = BLK_ZONED_NONE;
948 		break;
949 	}
950 
951 	q->limits.zoned = model;
952 	if (model != BLK_ZONED_NONE) {
953 		/*
954 		 * Set the zone write granularity to the device logical block
955 		 * size by default. The driver can change this value if needed.
956 		 */
957 		blk_queue_zone_write_granularity(q,
958 						queue_logical_block_size(q));
959 	} else if (old_model != BLK_ZONED_NONE) {
960 		disk_clear_zone_settings(disk);
961 	}
962 }
963 EXPORT_SYMBOL_GPL(disk_set_zoned);
964 
bdev_alignment_offset(struct block_device * bdev)965 int bdev_alignment_offset(struct block_device *bdev)
966 {
967 	struct request_queue *q = bdev_get_queue(bdev);
968 
969 	if (q->limits.misaligned)
970 		return -1;
971 	if (bdev_is_partition(bdev))
972 		return queue_limit_alignment_offset(&q->limits,
973 				bdev->bd_start_sect);
974 	return q->limits.alignment_offset;
975 }
976 EXPORT_SYMBOL_GPL(bdev_alignment_offset);
977 
bdev_discard_alignment(struct block_device * bdev)978 unsigned int bdev_discard_alignment(struct block_device *bdev)
979 {
980 	struct request_queue *q = bdev_get_queue(bdev);
981 
982 	if (bdev_is_partition(bdev))
983 		return queue_limit_discard_alignment(&q->limits,
984 				bdev->bd_start_sect);
985 	return q->limits.discard_alignment;
986 }
987 EXPORT_SYMBOL_GPL(bdev_discard_alignment);
988