xref: /linux/block/blk-settings.c (revision 11a299a7933e03c83818b431e6a1c53ad387423d)
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/blk-integrity.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_stacking_limits - set default limits for stacking devices
30  * @lim:  the queue_limits structure to reset
31  *
32  * Prepare queue limits for applying limits from underlying devices using
33  * blk_stack_limits().
34  */
blk_set_stacking_limits(struct queue_limits * lim)35 void blk_set_stacking_limits(struct queue_limits *lim)
36 {
37 	memset(lim, 0, sizeof(*lim));
38 	lim->logical_block_size = SECTOR_SIZE;
39 	lim->physical_block_size = SECTOR_SIZE;
40 	lim->io_min = SECTOR_SIZE;
41 	lim->discard_granularity = SECTOR_SIZE;
42 	lim->dma_alignment = SECTOR_SIZE - 1;
43 	lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
44 
45 	/* Inherit limits from component devices */
46 	lim->max_segments = USHRT_MAX;
47 	lim->max_discard_segments = USHRT_MAX;
48 	lim->max_hw_sectors = UINT_MAX;
49 	lim->max_segment_size = UINT_MAX;
50 	lim->max_sectors = UINT_MAX;
51 	lim->max_dev_sectors = UINT_MAX;
52 	lim->max_write_zeroes_sectors = UINT_MAX;
53 	lim->max_zone_append_sectors = UINT_MAX;
54 	lim->max_user_discard_sectors = UINT_MAX;
55 }
56 EXPORT_SYMBOL(blk_set_stacking_limits);
57 
blk_apply_bdi_limits(struct backing_dev_info * bdi,struct queue_limits * lim)58 void blk_apply_bdi_limits(struct backing_dev_info *bdi,
59 		struct queue_limits *lim)
60 {
61 	/*
62 	 * For read-ahead of large files to be effective, we need to read ahead
63 	 * at least twice the optimal I/O size.
64 	 */
65 	bdi->ra_pages = max(lim->io_opt * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
66 	bdi->io_pages = lim->max_sectors >> PAGE_SECTORS_SHIFT;
67 }
68 
blk_validate_zoned_limits(struct queue_limits * lim)69 static int blk_validate_zoned_limits(struct queue_limits *lim)
70 {
71 	if (!(lim->features & BLK_FEAT_ZONED)) {
72 		if (WARN_ON_ONCE(lim->max_open_zones) ||
73 		    WARN_ON_ONCE(lim->max_active_zones) ||
74 		    WARN_ON_ONCE(lim->zone_write_granularity) ||
75 		    WARN_ON_ONCE(lim->max_zone_append_sectors))
76 			return -EINVAL;
77 		return 0;
78 	}
79 
80 	if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED)))
81 		return -EINVAL;
82 
83 	/*
84 	 * Given that active zones include open zones, the maximum number of
85 	 * open zones cannot be larger than the maximum number of active zones.
86 	 */
87 	if (lim->max_active_zones &&
88 	    lim->max_open_zones > lim->max_active_zones)
89 		return -EINVAL;
90 
91 	if (lim->zone_write_granularity < lim->logical_block_size)
92 		lim->zone_write_granularity = lim->logical_block_size;
93 
94 	if (lim->max_zone_append_sectors) {
95 		/*
96 		 * The Zone Append size is limited by the maximum I/O size
97 		 * and the zone size given that it can't span zones.
98 		 */
99 		lim->max_zone_append_sectors =
100 			min3(lim->max_hw_sectors,
101 			     lim->max_zone_append_sectors,
102 			     lim->chunk_sectors);
103 	}
104 
105 	return 0;
106 }
107 
blk_validate_integrity_limits(struct queue_limits * lim)108 static int blk_validate_integrity_limits(struct queue_limits *lim)
109 {
110 	struct blk_integrity *bi = &lim->integrity;
111 
112 	if (!bi->tuple_size) {
113 		if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE ||
114 		    bi->tag_size || ((bi->flags & BLK_INTEGRITY_REF_TAG))) {
115 			pr_warn("invalid PI settings.\n");
116 			return -EINVAL;
117 		}
118 		return 0;
119 	}
120 
121 	if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) {
122 		pr_warn("integrity support disabled.\n");
123 		return -EINVAL;
124 	}
125 
126 	if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE &&
127 	    (bi->flags & BLK_INTEGRITY_REF_TAG)) {
128 		pr_warn("ref tag not support without checksum.\n");
129 		return -EINVAL;
130 	}
131 
132 	if (!bi->interval_exp)
133 		bi->interval_exp = ilog2(lim->logical_block_size);
134 
135 	return 0;
136 }
137 
138 /*
139  * Returns max guaranteed bytes which we can fit in a bio.
140  *
141  * We request that an atomic_write is ITER_UBUF iov_iter (so a single vector),
142  * so we assume that we can fit in at least PAGE_SIZE in a segment, apart from
143  * the first and last segments.
144  */
blk_queue_max_guaranteed_bio(struct queue_limits * lim)145 static unsigned int blk_queue_max_guaranteed_bio(struct queue_limits *lim)
146 {
147 	unsigned int max_segments = min(BIO_MAX_VECS, lim->max_segments);
148 	unsigned int length;
149 
150 	length = min(max_segments, 2) * lim->logical_block_size;
151 	if (max_segments > 2)
152 		length += (max_segments - 2) * PAGE_SIZE;
153 
154 	return length;
155 }
156 
blk_atomic_writes_update_limits(struct queue_limits * lim)157 static void blk_atomic_writes_update_limits(struct queue_limits *lim)
158 {
159 	unsigned int unit_limit = min(lim->max_hw_sectors << SECTOR_SHIFT,
160 					blk_queue_max_guaranteed_bio(lim));
161 
162 	unit_limit = rounddown_pow_of_two(unit_limit);
163 
164 	lim->atomic_write_max_sectors =
165 		min(lim->atomic_write_hw_max >> SECTOR_SHIFT,
166 			lim->max_hw_sectors);
167 	lim->atomic_write_unit_min =
168 		min(lim->atomic_write_hw_unit_min, unit_limit);
169 	lim->atomic_write_unit_max =
170 		min(lim->atomic_write_hw_unit_max, unit_limit);
171 	lim->atomic_write_boundary_sectors =
172 		lim->atomic_write_hw_boundary >> SECTOR_SHIFT;
173 }
174 
blk_validate_atomic_write_limits(struct queue_limits * lim)175 static void blk_validate_atomic_write_limits(struct queue_limits *lim)
176 {
177 	unsigned int boundary_sectors;
178 
179 	if (!lim->atomic_write_hw_max)
180 		goto unsupported;
181 
182 	boundary_sectors = lim->atomic_write_hw_boundary >> SECTOR_SHIFT;
183 
184 	if (boundary_sectors) {
185 		/*
186 		 * A feature of boundary support is that it disallows bios to
187 		 * be merged which would result in a merged request which
188 		 * crosses either a chunk sector or atomic write HW boundary,
189 		 * even though chunk sectors may be just set for performance.
190 		 * For simplicity, disallow atomic writes for a chunk sector
191 		 * which is non-zero and smaller than atomic write HW boundary.
192 		 * Furthermore, chunk sectors must be a multiple of atomic
193 		 * write HW boundary. Otherwise boundary support becomes
194 		 * complicated.
195 		 * Devices which do not conform to these rules can be dealt
196 		 * with if and when they show up.
197 		 */
198 		if (WARN_ON_ONCE(lim->chunk_sectors % boundary_sectors))
199 			goto unsupported;
200 
201 		/*
202 		 * The boundary size just needs to be a multiple of unit_max
203 		 * (and not necessarily a power-of-2), so this following check
204 		 * could be relaxed in future.
205 		 * Furthermore, if needed, unit_max could even be reduced so
206 		 * that it is compliant with a !power-of-2 boundary.
207 		 */
208 		if (!is_power_of_2(boundary_sectors))
209 			goto unsupported;
210 	}
211 
212 	blk_atomic_writes_update_limits(lim);
213 	return;
214 
215 unsupported:
216 	lim->atomic_write_max_sectors = 0;
217 	lim->atomic_write_boundary_sectors = 0;
218 	lim->atomic_write_unit_min = 0;
219 	lim->atomic_write_unit_max = 0;
220 }
221 
222 /*
223  * Check that the limits in lim are valid, initialize defaults for unset
224  * values, and cap values based on others where needed.
225  */
blk_validate_limits(struct queue_limits * lim)226 static int blk_validate_limits(struct queue_limits *lim)
227 {
228 	unsigned int max_hw_sectors;
229 	unsigned int logical_block_sectors;
230 	int err;
231 
232 	/*
233 	 * Unless otherwise specified, default to 512 byte logical blocks and a
234 	 * physical block size equal to the logical block size.
235 	 */
236 	if (!lim->logical_block_size)
237 		lim->logical_block_size = SECTOR_SIZE;
238 	else if (blk_validate_block_size(lim->logical_block_size)) {
239 		pr_warn("Invalid logical block size (%d)\n", lim->logical_block_size);
240 		return -EINVAL;
241 	}
242 	if (lim->physical_block_size < lim->logical_block_size)
243 		lim->physical_block_size = lim->logical_block_size;
244 
245 	/*
246 	 * The minimum I/O size defaults to the physical block size unless
247 	 * explicitly overridden.
248 	 */
249 	if (lim->io_min < lim->physical_block_size)
250 		lim->io_min = lim->physical_block_size;
251 
252 	/*
253 	 * max_hw_sectors has a somewhat weird default for historical reason,
254 	 * but driver really should set their own instead of relying on this
255 	 * value.
256 	 *
257 	 * The block layer relies on the fact that every driver can
258 	 * handle at lest a page worth of data per I/O, and needs the value
259 	 * aligned to the logical block size.
260 	 */
261 	if (!lim->max_hw_sectors)
262 		lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
263 	if (WARN_ON_ONCE(lim->max_hw_sectors < PAGE_SECTORS))
264 		return -EINVAL;
265 	logical_block_sectors = lim->logical_block_size >> SECTOR_SHIFT;
266 	if (WARN_ON_ONCE(logical_block_sectors > lim->max_hw_sectors))
267 		return -EINVAL;
268 	lim->max_hw_sectors = round_down(lim->max_hw_sectors,
269 			logical_block_sectors);
270 
271 	/*
272 	 * The actual max_sectors value is a complex beast and also takes the
273 	 * max_dev_sectors value (set by SCSI ULPs) and a user configurable
274 	 * value into account.  The ->max_sectors value is always calculated
275 	 * from these, so directly setting it won't have any effect.
276 	 */
277 	max_hw_sectors = min_not_zero(lim->max_hw_sectors,
278 				lim->max_dev_sectors);
279 	if (lim->max_user_sectors) {
280 		if (lim->max_user_sectors < PAGE_SIZE / SECTOR_SIZE)
281 			return -EINVAL;
282 		lim->max_sectors = min(max_hw_sectors, lim->max_user_sectors);
283 	} else if (lim->io_opt > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) {
284 		lim->max_sectors =
285 			min(max_hw_sectors, lim->io_opt >> SECTOR_SHIFT);
286 	} else if (lim->io_min > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) {
287 		lim->max_sectors =
288 			min(max_hw_sectors, lim->io_min >> SECTOR_SHIFT);
289 	} else {
290 		lim->max_sectors = min(max_hw_sectors, BLK_DEF_MAX_SECTORS_CAP);
291 	}
292 	lim->max_sectors = round_down(lim->max_sectors,
293 			logical_block_sectors);
294 
295 	/*
296 	 * Random default for the maximum number of segments.  Driver should not
297 	 * rely on this and set their own.
298 	 */
299 	if (!lim->max_segments)
300 		lim->max_segments = BLK_MAX_SEGMENTS;
301 
302 	lim->max_discard_sectors =
303 		min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors);
304 
305 	if (!lim->max_discard_segments)
306 		lim->max_discard_segments = 1;
307 
308 	if (lim->discard_granularity < lim->physical_block_size)
309 		lim->discard_granularity = lim->physical_block_size;
310 
311 	/*
312 	 * By default there is no limit on the segment boundary alignment,
313 	 * but if there is one it can't be smaller than the page size as
314 	 * that would break all the normal I/O patterns.
315 	 */
316 	if (!lim->seg_boundary_mask)
317 		lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
318 	if (WARN_ON_ONCE(lim->seg_boundary_mask < PAGE_SIZE - 1))
319 		return -EINVAL;
320 
321 	/*
322 	 * Stacking device may have both virtual boundary and max segment
323 	 * size limit, so allow this setting now, and long-term the two
324 	 * might need to move out of stacking limits since we have immutable
325 	 * bvec and lower layer bio splitting is supposed to handle the two
326 	 * correctly.
327 	 */
328 	if (lim->virt_boundary_mask) {
329 		if (!lim->max_segment_size)
330 			lim->max_segment_size = UINT_MAX;
331 	} else {
332 		/*
333 		 * The maximum segment size has an odd historic 64k default that
334 		 * drivers probably should override.  Just like the I/O size we
335 		 * require drivers to at least handle a full page per segment.
336 		 */
337 		if (!lim->max_segment_size)
338 			lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
339 		if (WARN_ON_ONCE(lim->max_segment_size < PAGE_SIZE))
340 			return -EINVAL;
341 	}
342 
343 	/*
344 	 * We require drivers to at least do logical block aligned I/O, but
345 	 * historically could not check for that due to the separate calls
346 	 * to set the limits.  Once the transition is finished the check
347 	 * below should be narrowed down to check the logical block size.
348 	 */
349 	if (!lim->dma_alignment)
350 		lim->dma_alignment = SECTOR_SIZE - 1;
351 	if (WARN_ON_ONCE(lim->dma_alignment > PAGE_SIZE))
352 		return -EINVAL;
353 
354 	if (lim->alignment_offset) {
355 		lim->alignment_offset &= (lim->physical_block_size - 1);
356 		lim->flags &= ~BLK_FLAG_MISALIGNED;
357 	}
358 
359 	if (!(lim->features & BLK_FEAT_WRITE_CACHE))
360 		lim->features &= ~BLK_FEAT_FUA;
361 
362 	blk_validate_atomic_write_limits(lim);
363 
364 	err = blk_validate_integrity_limits(lim);
365 	if (err)
366 		return err;
367 	return blk_validate_zoned_limits(lim);
368 }
369 
370 /*
371  * Set the default limits for a newly allocated queue.  @lim contains the
372  * initial limits set by the driver, which could be no limit in which case
373  * all fields are cleared to zero.
374  */
blk_set_default_limits(struct queue_limits * lim)375 int blk_set_default_limits(struct queue_limits *lim)
376 {
377 	/*
378 	 * Most defaults are set by capping the bounds in blk_validate_limits,
379 	 * but max_user_discard_sectors is special and needs an explicit
380 	 * initialization to the max value here.
381 	 */
382 	lim->max_user_discard_sectors = UINT_MAX;
383 	return blk_validate_limits(lim);
384 }
385 
386 /**
387  * queue_limits_commit_update - commit an atomic update of queue limits
388  * @q:		queue to update
389  * @lim:	limits to apply
390  *
391  * Apply the limits in @lim that were obtained from queue_limits_start_update()
392  * and updated by the caller to @q.
393  *
394  * Returns 0 if successful, else a negative error code.
395  */
queue_limits_commit_update(struct request_queue * q,struct queue_limits * lim)396 int queue_limits_commit_update(struct request_queue *q,
397 		struct queue_limits *lim)
398 {
399 	int error;
400 
401 	error = blk_validate_limits(lim);
402 	if (error)
403 		goto out_unlock;
404 
405 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
406 	if (q->crypto_profile && lim->integrity.tag_size) {
407 		pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together.\n");
408 		error = -EINVAL;
409 		goto out_unlock;
410 	}
411 #endif
412 
413 	q->limits = *lim;
414 	if (q->disk)
415 		blk_apply_bdi_limits(q->disk->bdi, lim);
416 out_unlock:
417 	mutex_unlock(&q->limits_lock);
418 	return error;
419 }
420 EXPORT_SYMBOL_GPL(queue_limits_commit_update);
421 
422 /**
423  * queue_limits_set - apply queue limits to queue
424  * @q:		queue to update
425  * @lim:	limits to apply
426  *
427  * Apply the limits in @lim that were freshly initialized to @q.
428  * To update existing limits use queue_limits_start_update() and
429  * queue_limits_commit_update() instead.
430  *
431  * Returns 0 if successful, else a negative error code.
432  */
queue_limits_set(struct request_queue * q,struct queue_limits * lim)433 int queue_limits_set(struct request_queue *q, struct queue_limits *lim)
434 {
435 	mutex_lock(&q->limits_lock);
436 	return queue_limits_commit_update(q, lim);
437 }
438 EXPORT_SYMBOL_GPL(queue_limits_set);
439 
queue_limit_alignment_offset(const struct queue_limits * lim,sector_t sector)440 static int queue_limit_alignment_offset(const struct queue_limits *lim,
441 		sector_t sector)
442 {
443 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
444 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
445 		<< SECTOR_SHIFT;
446 
447 	return (granularity + lim->alignment_offset - alignment) % granularity;
448 }
449 
queue_limit_discard_alignment(const struct queue_limits * lim,sector_t sector)450 static unsigned int queue_limit_discard_alignment(
451 		const struct queue_limits *lim, sector_t sector)
452 {
453 	unsigned int alignment, granularity, offset;
454 
455 	if (!lim->max_discard_sectors)
456 		return 0;
457 
458 	/* Why are these in bytes, not sectors? */
459 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
460 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
461 	if (!granularity)
462 		return 0;
463 
464 	/* Offset of the partition start in 'granularity' sectors */
465 	offset = sector_div(sector, granularity);
466 
467 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
468 	offset = (granularity + alignment - offset) % granularity;
469 
470 	/* Turn it back into bytes, gaah */
471 	return offset << SECTOR_SHIFT;
472 }
473 
blk_round_down_sectors(unsigned int sectors,unsigned int lbs)474 static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs)
475 {
476 	sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
477 	if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
478 		sectors = PAGE_SIZE >> SECTOR_SHIFT;
479 	return sectors;
480 }
481 
482 /**
483  * blk_stack_limits - adjust queue_limits for stacked devices
484  * @t:	the stacking driver limits (top device)
485  * @b:  the underlying queue limits (bottom, component device)
486  * @start:  first data sector within component device
487  *
488  * Description:
489  *    This function is used by stacking drivers like MD and DM to ensure
490  *    that all component devices have compatible block sizes and
491  *    alignments.  The stacking driver must provide a queue_limits
492  *    struct (top) and then iteratively call the stacking function for
493  *    all component (bottom) devices.  The stacking function will
494  *    attempt to combine the values and ensure proper alignment.
495  *
496  *    Returns 0 if the top and bottom queue_limits are compatible.  The
497  *    top device's block sizes and alignment offsets may be adjusted to
498  *    ensure alignment with the bottom device. If no compatible sizes
499  *    and alignments exist, -1 is returned and the resulting top
500  *    queue_limits will have the misaligned flag set to indicate that
501  *    the alignment_offset is undefined.
502  */
blk_stack_limits(struct queue_limits * t,struct queue_limits * b,sector_t start)503 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
504 		     sector_t start)
505 {
506 	unsigned int top, bottom, alignment, ret = 0;
507 
508 	t->features |= (b->features & BLK_FEAT_INHERIT_MASK);
509 
510 	/*
511 	 * BLK_FEAT_NOWAIT and BLK_FEAT_POLL need to be supported both by the
512 	 * stacking driver and all underlying devices.  The stacking driver sets
513 	 * the flags before stacking the limits, and this will clear the flags
514 	 * if any of the underlying devices does not support it.
515 	 */
516 	if (!(b->features & BLK_FEAT_NOWAIT))
517 		t->features &= ~BLK_FEAT_NOWAIT;
518 	if (!(b->features & BLK_FEAT_POLL))
519 		t->features &= ~BLK_FEAT_POLL;
520 
521 	t->flags |= (b->flags & BLK_FLAG_MISALIGNED);
522 
523 	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
524 	t->max_user_sectors = min_not_zero(t->max_user_sectors,
525 			b->max_user_sectors);
526 	t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
527 	t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
528 	t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
529 					b->max_write_zeroes_sectors);
530 	t->max_zone_append_sectors = min(queue_limits_max_zone_append_sectors(t),
531 					 queue_limits_max_zone_append_sectors(b));
532 
533 	t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
534 					    b->seg_boundary_mask);
535 	t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
536 					    b->virt_boundary_mask);
537 
538 	t->max_segments = min_not_zero(t->max_segments, b->max_segments);
539 	t->max_discard_segments = min_not_zero(t->max_discard_segments,
540 					       b->max_discard_segments);
541 	t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
542 						 b->max_integrity_segments);
543 
544 	t->max_segment_size = min_not_zero(t->max_segment_size,
545 					   b->max_segment_size);
546 
547 	alignment = queue_limit_alignment_offset(b, start);
548 
549 	/* Bottom device has different alignment.  Check that it is
550 	 * compatible with the current top alignment.
551 	 */
552 	if (t->alignment_offset != alignment) {
553 
554 		top = max(t->physical_block_size, t->io_min)
555 			+ t->alignment_offset;
556 		bottom = max(b->physical_block_size, b->io_min) + alignment;
557 
558 		/* Verify that top and bottom intervals line up */
559 		if (max(top, bottom) % min(top, bottom)) {
560 			t->flags |= BLK_FLAG_MISALIGNED;
561 			ret = -1;
562 		}
563 	}
564 
565 	t->logical_block_size = max(t->logical_block_size,
566 				    b->logical_block_size);
567 
568 	t->physical_block_size = max(t->physical_block_size,
569 				     b->physical_block_size);
570 
571 	t->io_min = max(t->io_min, b->io_min);
572 	t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
573 	t->dma_alignment = max(t->dma_alignment, b->dma_alignment);
574 
575 	/* Set non-power-of-2 compatible chunk_sectors boundary */
576 	if (b->chunk_sectors)
577 		t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors);
578 
579 	/* Physical block size a multiple of the logical block size? */
580 	if (t->physical_block_size & (t->logical_block_size - 1)) {
581 		t->physical_block_size = t->logical_block_size;
582 		t->flags |= BLK_FLAG_MISALIGNED;
583 		ret = -1;
584 	}
585 
586 	/* Minimum I/O a multiple of the physical block size? */
587 	if (t->io_min & (t->physical_block_size - 1)) {
588 		t->io_min = t->physical_block_size;
589 		t->flags |= BLK_FLAG_MISALIGNED;
590 		ret = -1;
591 	}
592 
593 	/* Optimal I/O a multiple of the physical block size? */
594 	if (t->io_opt & (t->physical_block_size - 1)) {
595 		t->io_opt = 0;
596 		t->flags |= BLK_FLAG_MISALIGNED;
597 		ret = -1;
598 	}
599 
600 	/* chunk_sectors a multiple of the physical block size? */
601 	if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) {
602 		t->chunk_sectors = 0;
603 		t->flags |= BLK_FLAG_MISALIGNED;
604 		ret = -1;
605 	}
606 
607 	/* Find lowest common alignment_offset */
608 	t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
609 		% max(t->physical_block_size, t->io_min);
610 
611 	/* Verify that new alignment_offset is on a logical block boundary */
612 	if (t->alignment_offset & (t->logical_block_size - 1)) {
613 		t->flags |= BLK_FLAG_MISALIGNED;
614 		ret = -1;
615 	}
616 
617 	t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size);
618 	t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size);
619 	t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size);
620 
621 	/* Discard alignment and granularity */
622 	if (b->discard_granularity) {
623 		alignment = queue_limit_discard_alignment(b, start);
624 
625 		t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
626 						      b->max_discard_sectors);
627 		t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
628 							 b->max_hw_discard_sectors);
629 		t->discard_granularity = max(t->discard_granularity,
630 					     b->discard_granularity);
631 		t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
632 			t->discard_granularity;
633 	}
634 	t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors,
635 						   b->max_secure_erase_sectors);
636 	t->zone_write_granularity = max(t->zone_write_granularity,
637 					b->zone_write_granularity);
638 	if (!(t->features & BLK_FEAT_ZONED)) {
639 		t->zone_write_granularity = 0;
640 		t->max_zone_append_sectors = 0;
641 	}
642 	return ret;
643 }
644 EXPORT_SYMBOL(blk_stack_limits);
645 
646 /**
647  * queue_limits_stack_bdev - adjust queue_limits for stacked devices
648  * @t:	the stacking driver limits (top device)
649  * @bdev:  the underlying block device (bottom)
650  * @offset:  offset to beginning of data within component device
651  * @pfx: prefix to use for warnings logged
652  *
653  * Description:
654  *    This function is used by stacking drivers like MD and DM to ensure
655  *    that all component devices have compatible block sizes and
656  *    alignments.  The stacking driver must provide a queue_limits
657  *    struct (top) and then iteratively call the stacking function for
658  *    all component (bottom) devices.  The stacking function will
659  *    attempt to combine the values and ensure proper alignment.
660  */
queue_limits_stack_bdev(struct queue_limits * t,struct block_device * bdev,sector_t offset,const char * pfx)661 void queue_limits_stack_bdev(struct queue_limits *t, struct block_device *bdev,
662 		sector_t offset, const char *pfx)
663 {
664 	if (blk_stack_limits(t, &bdev_get_queue(bdev)->limits,
665 			get_start_sect(bdev) + offset))
666 		pr_notice("%s: Warning: Device %pg is misaligned\n",
667 			pfx, bdev);
668 }
669 EXPORT_SYMBOL_GPL(queue_limits_stack_bdev);
670 
671 /**
672  * queue_limits_stack_integrity - stack integrity profile
673  * @t: target queue limits
674  * @b: base queue limits
675  *
676  * Check if the integrity profile in the @b can be stacked into the
677  * target @t.  Stacking is possible if either:
678  *
679  *   a) does not have any integrity information stacked into it yet
680  *   b) the integrity profile in @b is identical to the one in @t
681  *
682  * If @b can be stacked into @t, return %true.  Else return %false and clear the
683  * integrity information in @t.
684  */
queue_limits_stack_integrity(struct queue_limits * t,struct queue_limits * b)685 bool queue_limits_stack_integrity(struct queue_limits *t,
686 		struct queue_limits *b)
687 {
688 	struct blk_integrity *ti = &t->integrity;
689 	struct blk_integrity *bi = &b->integrity;
690 
691 	if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY))
692 		return true;
693 
694 	if (!ti->tuple_size) {
695 		/* inherit the settings from the first underlying device */
696 		if (!(ti->flags & BLK_INTEGRITY_STACKED)) {
697 			ti->flags = BLK_INTEGRITY_DEVICE_CAPABLE |
698 				(bi->flags & BLK_INTEGRITY_REF_TAG);
699 			ti->csum_type = bi->csum_type;
700 			ti->tuple_size = bi->tuple_size;
701 			ti->pi_offset = bi->pi_offset;
702 			ti->interval_exp = bi->interval_exp;
703 			ti->tag_size = bi->tag_size;
704 			goto done;
705 		}
706 		if (!bi->tuple_size)
707 			goto done;
708 	}
709 
710 	if (ti->tuple_size != bi->tuple_size)
711 		goto incompatible;
712 	if (ti->interval_exp != bi->interval_exp)
713 		goto incompatible;
714 	if (ti->tag_size != bi->tag_size)
715 		goto incompatible;
716 	if (ti->csum_type != bi->csum_type)
717 		goto incompatible;
718 	if ((ti->flags & BLK_INTEGRITY_REF_TAG) !=
719 	    (bi->flags & BLK_INTEGRITY_REF_TAG))
720 		goto incompatible;
721 
722 done:
723 	ti->flags |= BLK_INTEGRITY_STACKED;
724 	return true;
725 
726 incompatible:
727 	memset(ti, 0, sizeof(*ti));
728 	return false;
729 }
730 EXPORT_SYMBOL_GPL(queue_limits_stack_integrity);
731 
732 /**
733  * blk_set_queue_depth - tell the block layer about the device queue depth
734  * @q:		the request queue for the device
735  * @depth:		queue depth
736  *
737  */
blk_set_queue_depth(struct request_queue * q,unsigned int depth)738 void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
739 {
740 	q->queue_depth = depth;
741 	rq_qos_queue_depth_changed(q);
742 }
743 EXPORT_SYMBOL(blk_set_queue_depth);
744 
bdev_alignment_offset(struct block_device * bdev)745 int bdev_alignment_offset(struct block_device *bdev)
746 {
747 	struct request_queue *q = bdev_get_queue(bdev);
748 
749 	if (q->limits.flags & BLK_FLAG_MISALIGNED)
750 		return -1;
751 	if (bdev_is_partition(bdev))
752 		return queue_limit_alignment_offset(&q->limits,
753 				bdev->bd_start_sect);
754 	return q->limits.alignment_offset;
755 }
756 EXPORT_SYMBOL_GPL(bdev_alignment_offset);
757 
bdev_discard_alignment(struct block_device * bdev)758 unsigned int bdev_discard_alignment(struct block_device *bdev)
759 {
760 	struct request_queue *q = bdev_get_queue(bdev);
761 
762 	if (bdev_is_partition(bdev))
763 		return queue_limit_discard_alignment(&q->limits,
764 				bdev->bd_start_sect);
765 	return q->limits.discard_alignment;
766 }
767 EXPORT_SYMBOL_GPL(bdev_discard_alignment);
768