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