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/memblock.h> /* for max_pfn/max_low_pfn */ 11#include <linux/gcd.h> 12#include <linux/lcm.h> 13#include <linux/jiffies.h> 14#include <linux/gfp.h> 15#include <linux/dma-mapping.h> 16 17#include "blk.h" 18#include "blk-wbt.h" 19 20unsigned long blk_max_low_pfn; 21EXPORT_SYMBOL(blk_max_low_pfn); 22 23unsigned long blk_max_pfn; 24 25void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) 26{ 27 q->rq_timeout = timeout; 28} 29EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); 30 31/** 32 * blk_set_default_limits - reset limits to default values 33 * @lim: the queue_limits structure to reset 34 * 35 * Description: 36 * Returns a queue_limit struct to its default state. 37 */ 38void blk_set_default_limits(struct queue_limits *lim) 39{ 40 lim->max_segments = BLK_MAX_SEGMENTS; 41 lim->max_discard_segments = 1; 42 lim->max_integrity_segments = 0; 43 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; 44 lim->virt_boundary_mask = 0; 45 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; 46 lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; 47 lim->max_dev_sectors = 0; 48 lim->chunk_sectors = 0; 49 lim->max_write_same_sectors = 0; 50 lim->max_write_zeroes_sectors = 0; 51 lim->max_zone_append_sectors = 0; 52 lim->max_discard_sectors = 0; 53 lim->max_hw_discard_sectors = 0; 54 lim->discard_granularity = 0; 55 lim->discard_alignment = 0; 56 lim->discard_misaligned = 0; 57 lim->logical_block_size = lim->physical_block_size = lim->io_min = 512; 58 lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT); 59 lim->alignment_offset = 0; 60 lim->io_opt = 0; 61 lim->misaligned = 0; 62 lim->zoned = BLK_ZONED_NONE; 63} 64EXPORT_SYMBOL(blk_set_default_limits); 65 66/** 67 * blk_set_stacking_limits - set default limits for stacking devices 68 * @lim: the queue_limits structure to reset 69 * 70 * Description: 71 * Returns a queue_limit struct to its default state. Should be used 72 * by stacking drivers like DM that have no internal limits. 73 */ 74void blk_set_stacking_limits(struct queue_limits *lim) 75{ 76 blk_set_default_limits(lim); 77 78 /* Inherit limits from component devices */ 79 lim->max_segments = USHRT_MAX; 80 lim->max_discard_segments = USHRT_MAX; 81 lim->max_hw_sectors = UINT_MAX; 82 lim->max_segment_size = UINT_MAX; 83 lim->max_sectors = UINT_MAX; 84 lim->max_dev_sectors = UINT_MAX; 85 lim->max_write_same_sectors = UINT_MAX; 86 lim->max_write_zeroes_sectors = UINT_MAX; 87 lim->max_zone_append_sectors = UINT_MAX; 88} 89EXPORT_SYMBOL(blk_set_stacking_limits); 90 91/** 92 * blk_queue_bounce_limit - set bounce buffer limit for queue 93 * @q: the request queue for the device 94 * @max_addr: the maximum address the device can handle 95 * 96 * Description: 97 * Different hardware can have different requirements as to what pages 98 * it can do I/O directly to. A low level driver can call 99 * blk_queue_bounce_limit to have lower memory pages allocated as bounce 100 * buffers for doing I/O to pages residing above @max_addr. 101 **/ 102void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr) 103{ 104 unsigned long b_pfn = max_addr >> PAGE_SHIFT; 105 int dma = 0; 106 107 q->bounce_gfp = GFP_NOIO; 108#if BITS_PER_LONG == 64 109 /* 110 * Assume anything <= 4GB can be handled by IOMMU. Actually 111 * some IOMMUs can handle everything, but I don't know of a 112 * way to test this here. 113 */ 114 if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT)) 115 dma = 1; 116 q->limits.bounce_pfn = max(max_low_pfn, b_pfn); 117#else 118 if (b_pfn < blk_max_low_pfn) 119 dma = 1; 120 q->limits.bounce_pfn = b_pfn; 121#endif 122 if (dma) { 123 init_emergency_isa_pool(); 124 q->bounce_gfp = GFP_NOIO | GFP_DMA; 125 q->limits.bounce_pfn = b_pfn; 126 } 127} 128EXPORT_SYMBOL(blk_queue_bounce_limit); 129 130/** 131 * blk_queue_max_hw_sectors - set max sectors for a request for this queue 132 * @q: the request queue for the device 133 * @max_hw_sectors: max hardware sectors in the usual 512b unit 134 * 135 * Description: 136 * Enables a low level driver to set a hard upper limit, 137 * max_hw_sectors, on the size of requests. max_hw_sectors is set by 138 * the device driver based upon the capabilities of the I/O 139 * controller. 140 * 141 * max_dev_sectors is a hard limit imposed by the storage device for 142 * READ/WRITE requests. It is set by the disk driver. 143 * 144 * max_sectors is a soft limit imposed by the block layer for 145 * filesystem type requests. This value can be overridden on a 146 * per-device basis in /sys/block/<device>/queue/max_sectors_kb. 147 * The soft limit can not exceed max_hw_sectors. 148 **/ 149void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors) 150{ 151 struct queue_limits *limits = &q->limits; 152 unsigned int max_sectors; 153 154 if ((max_hw_sectors << 9) < PAGE_SIZE) { 155 max_hw_sectors = 1 << (PAGE_SHIFT - 9); 156 printk(KERN_INFO "%s: set to minimum %d\n", 157 __func__, max_hw_sectors); 158 } 159 160 limits->max_hw_sectors = max_hw_sectors; 161 max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); 162 max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); 163 limits->max_sectors = max_sectors; 164 q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - 9); 165} 166EXPORT_SYMBOL(blk_queue_max_hw_sectors); 167 168/** 169 * blk_queue_chunk_sectors - set size of the chunk for this queue 170 * @q: the request queue for the device 171 * @chunk_sectors: chunk sectors in the usual 512b unit 172 * 173 * Description: 174 * If a driver doesn't want IOs to cross a given chunk size, it can set 175 * this limit and prevent merging across chunks. Note that the block layer 176 * must accept a page worth of data at any offset. So if the crossing of 177 * chunks is a hard limitation in the driver, it must still be prepared 178 * to split single page bios. 179 **/ 180void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors) 181{ 182 q->limits.chunk_sectors = chunk_sectors; 183} 184EXPORT_SYMBOL(blk_queue_chunk_sectors); 185 186/** 187 * blk_queue_max_discard_sectors - set max sectors for a single discard 188 * @q: the request queue for the device 189 * @max_discard_sectors: maximum number of sectors to discard 190 **/ 191void blk_queue_max_discard_sectors(struct request_queue *q, 192 unsigned int max_discard_sectors) 193{ 194 q->limits.max_hw_discard_sectors = max_discard_sectors; 195 q->limits.max_discard_sectors = max_discard_sectors; 196} 197EXPORT_SYMBOL(blk_queue_max_discard_sectors); 198 199/** 200 * blk_queue_max_write_same_sectors - set max sectors for a single write same 201 * @q: the request queue for the device 202 * @max_write_same_sectors: maximum number of sectors to write per command 203 **/ 204void blk_queue_max_write_same_sectors(struct request_queue *q, 205 unsigned int max_write_same_sectors) 206{ 207 q->limits.max_write_same_sectors = max_write_same_sectors; 208} 209EXPORT_SYMBOL(blk_queue_max_write_same_sectors); 210 211/** 212 * blk_queue_max_write_zeroes_sectors - set max sectors for a single 213 * write zeroes 214 * @q: the request queue for the device 215 * @max_write_zeroes_sectors: maximum number of sectors to write per command 216 **/ 217void blk_queue_max_write_zeroes_sectors(struct request_queue *q, 218 unsigned int max_write_zeroes_sectors) 219{ 220 q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors; 221} 222EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors); 223 224/** 225 * blk_queue_max_zone_append_sectors - set max sectors for a single zone append 226 * @q: the request queue for the device 227 * @max_zone_append_sectors: maximum number of sectors to write per command 228 **/ 229void blk_queue_max_zone_append_sectors(struct request_queue *q, 230 unsigned int max_zone_append_sectors) 231{ 232 unsigned int max_sectors; 233 234 if (WARN_ON(!blk_queue_is_zoned(q))) 235 return; 236 237 max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors); 238 max_sectors = min(q->limits.chunk_sectors, max_sectors); 239 240 /* 241 * Signal eventual driver bugs resulting in the max_zone_append sectors limit 242 * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set, 243 * or the max_hw_sectors limit not set. 244 */ 245 WARN_ON(!max_sectors); 246 247 q->limits.max_zone_append_sectors = max_sectors; 248} 249EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors); 250 251/** 252 * blk_queue_max_segments - set max hw segments for a request for this queue 253 * @q: the request queue for the device 254 * @max_segments: max number of segments 255 * 256 * Description: 257 * Enables a low level driver to set an upper limit on the number of 258 * hw data segments in a request. 259 **/ 260void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments) 261{ 262 if (!max_segments) { 263 max_segments = 1; 264 printk(KERN_INFO "%s: set to minimum %d\n", 265 __func__, max_segments); 266 } 267 268 q->limits.max_segments = max_segments; 269} 270EXPORT_SYMBOL(blk_queue_max_segments); 271 272/** 273 * blk_queue_max_discard_segments - set max segments for discard requests 274 * @q: the request queue for the device 275 * @max_segments: max number of segments 276 * 277 * Description: 278 * Enables a low level driver to set an upper limit on the number of 279 * segments in a discard request. 280 **/ 281void blk_queue_max_discard_segments(struct request_queue *q, 282 unsigned short max_segments) 283{ 284 q->limits.max_discard_segments = max_segments; 285} 286EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments); 287 288/** 289 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg 290 * @q: the request queue for the device 291 * @max_size: max size of segment in bytes 292 * 293 * Description: 294 * Enables a low level driver to set an upper limit on the size of a 295 * coalesced segment 296 **/ 297void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size) 298{ 299 if (max_size < PAGE_SIZE) { 300 max_size = PAGE_SIZE; 301 printk(KERN_INFO "%s: set to minimum %d\n", 302 __func__, max_size); 303 } 304 305 /* see blk_queue_virt_boundary() for the explanation */ 306 WARN_ON_ONCE(q->limits.virt_boundary_mask); 307 308 q->limits.max_segment_size = max_size; 309} 310EXPORT_SYMBOL(blk_queue_max_segment_size); 311 312/** 313 * blk_queue_logical_block_size - set logical block size for the queue 314 * @q: the request queue for the device 315 * @size: the logical block size, in bytes 316 * 317 * Description: 318 * This should be set to the lowest possible block size that the 319 * storage device can address. The default of 512 covers most 320 * hardware. 321 **/ 322void blk_queue_logical_block_size(struct request_queue *q, unsigned int size) 323{ 324 q->limits.logical_block_size = size; 325 326 if (q->limits.physical_block_size < size) 327 q->limits.physical_block_size = size; 328 329 if (q->limits.io_min < q->limits.physical_block_size) 330 q->limits.io_min = q->limits.physical_block_size; 331} 332EXPORT_SYMBOL(blk_queue_logical_block_size); 333 334/** 335 * blk_queue_physical_block_size - set physical block size for the queue 336 * @q: the request queue for the device 337 * @size: the physical block size, in bytes 338 * 339 * Description: 340 * This should be set to the lowest possible sector size that the 341 * hardware can operate on without reverting to read-modify-write 342 * operations. 343 */ 344void blk_queue_physical_block_size(struct request_queue *q, unsigned int size) 345{ 346 q->limits.physical_block_size = size; 347 348 if (q->limits.physical_block_size < q->limits.logical_block_size) 349 q->limits.physical_block_size = q->limits.logical_block_size; 350 351 if (q->limits.io_min < q->limits.physical_block_size) 352 q->limits.io_min = q->limits.physical_block_size; 353} 354EXPORT_SYMBOL(blk_queue_physical_block_size); 355 356/** 357 * blk_queue_alignment_offset - set physical block alignment offset 358 * @q: the request queue for the device 359 * @offset: alignment offset in bytes 360 * 361 * Description: 362 * Some devices are naturally misaligned to compensate for things like 363 * the legacy DOS partition table 63-sector offset. Low-level drivers 364 * should call this function for devices whose first sector is not 365 * naturally aligned. 366 */ 367void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) 368{ 369 q->limits.alignment_offset = 370 offset & (q->limits.physical_block_size - 1); 371 q->limits.misaligned = 0; 372} 373EXPORT_SYMBOL(blk_queue_alignment_offset); 374 375void blk_queue_update_readahead(struct request_queue *q) 376{ 377 /* 378 * For read-ahead of large files to be effective, we need to read ahead 379 * at least twice the optimal I/O size. 380 */ 381 q->backing_dev_info->ra_pages = 382 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES); 383 q->backing_dev_info->io_pages = 384 queue_max_sectors(q) >> (PAGE_SHIFT - 9); 385} 386EXPORT_SYMBOL_GPL(blk_queue_update_readahead); 387 388/** 389 * blk_limits_io_min - set minimum request size for a device 390 * @limits: the queue limits 391 * @min: smallest I/O size in bytes 392 * 393 * Description: 394 * Some devices have an internal block size bigger than the reported 395 * hardware sector size. This function can be used to signal the 396 * smallest I/O the device can perform without incurring a performance 397 * penalty. 398 */ 399void blk_limits_io_min(struct queue_limits *limits, unsigned int min) 400{ 401 limits->io_min = min; 402 403 if (limits->io_min < limits->logical_block_size) 404 limits->io_min = limits->logical_block_size; 405 406 if (limits->io_min < limits->physical_block_size) 407 limits->io_min = limits->physical_block_size; 408} 409EXPORT_SYMBOL(blk_limits_io_min); 410 411/** 412 * blk_queue_io_min - set minimum request size for the queue 413 * @q: the request queue for the device 414 * @min: smallest I/O size in bytes 415 * 416 * Description: 417 * Storage devices may report a granularity or preferred minimum I/O 418 * size which is the smallest request the device can perform without 419 * incurring a performance penalty. For disk drives this is often the 420 * physical block size. For RAID arrays it is often the stripe chunk 421 * size. A properly aligned multiple of minimum_io_size is the 422 * preferred request size for workloads where a high number of I/O 423 * operations is desired. 424 */ 425void blk_queue_io_min(struct request_queue *q, unsigned int min) 426{ 427 blk_limits_io_min(&q->limits, min); 428} 429EXPORT_SYMBOL(blk_queue_io_min); 430 431/** 432 * blk_limits_io_opt - set optimal request size for a device 433 * @limits: the queue limits 434 * @opt: smallest I/O size in bytes 435 * 436 * Description: 437 * Storage devices may report an optimal I/O size, which is the 438 * device's preferred unit for sustained I/O. This is rarely reported 439 * for disk drives. For RAID arrays it is usually the stripe width or 440 * the internal track size. A properly aligned multiple of 441 * optimal_io_size is the preferred request size for workloads where 442 * sustained throughput is desired. 443 */ 444void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt) 445{ 446 limits->io_opt = opt; 447} 448EXPORT_SYMBOL(blk_limits_io_opt); 449 450/** 451 * blk_queue_io_opt - set optimal request size for the queue 452 * @q: the request queue for the device 453 * @opt: optimal request size in bytes 454 * 455 * Description: 456 * Storage devices may report an optimal I/O size, which is the 457 * device's preferred unit for sustained I/O. This is rarely reported 458 * for disk drives. For RAID arrays it is usually the stripe width or 459 * the internal track size. A properly aligned multiple of 460 * optimal_io_size is the preferred request size for workloads where 461 * sustained throughput is desired. 462 */ 463void blk_queue_io_opt(struct request_queue *q, unsigned int opt) 464{ 465 blk_limits_io_opt(&q->limits, opt); 466 q->backing_dev_info->ra_pages = 467 max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES); 468} 469EXPORT_SYMBOL(blk_queue_io_opt); 470 471static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs) 472{ 473 sectors = round_down(sectors, lbs >> SECTOR_SHIFT); 474 if (sectors < PAGE_SIZE >> SECTOR_SHIFT) 475 sectors = PAGE_SIZE >> SECTOR_SHIFT; 476 return sectors; 477} 478 479/** 480 * blk_stack_limits - adjust queue_limits for stacked devices 481 * @t: the stacking driver limits (top device) 482 * @b: the underlying queue limits (bottom, component device) 483 * @start: first data sector within component device 484 * 485 * Description: 486 * This function is used by stacking drivers like MD and DM to ensure 487 * that all component devices have compatible block sizes and 488 * alignments. The stacking driver must provide a queue_limits 489 * struct (top) and then iteratively call the stacking function for 490 * all component (bottom) devices. The stacking function will 491 * attempt to combine the values and ensure proper alignment. 492 * 493 * Returns 0 if the top and bottom queue_limits are compatible. The 494 * top device's block sizes and alignment offsets may be adjusted to 495 * ensure alignment with the bottom device. If no compatible sizes 496 * and alignments exist, -1 is returned and the resulting top 497 * queue_limits will have the misaligned flag set to indicate that 498 * the alignment_offset is undefined. 499 */ 500int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 501 sector_t start) 502{ 503 unsigned int top, bottom, alignment, ret = 0; 504 505 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); 506 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); 507 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); 508 t->max_write_same_sectors = min(t->max_write_same_sectors, 509 b->max_write_same_sectors); 510 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, 511 b->max_write_zeroes_sectors); 512 t->max_zone_append_sectors = min(t->max_zone_append_sectors, 513 b->max_zone_append_sectors); 514 t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn); 515 516 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, 517 b->seg_boundary_mask); 518 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, 519 b->virt_boundary_mask); 520 521 t->max_segments = min_not_zero(t->max_segments, b->max_segments); 522 t->max_discard_segments = min_not_zero(t->max_discard_segments, 523 b->max_discard_segments); 524 t->max_integrity_segments = min_not_zero(t->max_integrity_segments, 525 b->max_integrity_segments); 526 527 t->max_segment_size = min_not_zero(t->max_segment_size, 528 b->max_segment_size); 529 530 t->misaligned |= b->misaligned; 531 532 alignment = queue_limit_alignment_offset(b, start); 533 534 /* Bottom device has different alignment. Check that it is 535 * compatible with the current top alignment. 536 */ 537 if (t->alignment_offset != alignment) { 538 539 top = max(t->physical_block_size, t->io_min) 540 + t->alignment_offset; 541 bottom = max(b->physical_block_size, b->io_min) + alignment; 542 543 /* Verify that top and bottom intervals line up */ 544 if (max(top, bottom) % min(top, bottom)) { 545 t->misaligned = 1; 546 ret = -1; 547 } 548 } 549 550 t->logical_block_size = max(t->logical_block_size, 551 b->logical_block_size); 552 553 t->physical_block_size = max(t->physical_block_size, 554 b->physical_block_size); 555 556 t->io_min = max(t->io_min, b->io_min); 557 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); 558 559 /* Set non-power-of-2 compatible chunk_sectors boundary */ 560 if (b->chunk_sectors) 561 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors); 562 563 /* Physical block size a multiple of the logical block size? */ 564 if (t->physical_block_size & (t->logical_block_size - 1)) { 565 t->physical_block_size = t->logical_block_size; 566 t->misaligned = 1; 567 ret = -1; 568 } 569 570 /* Minimum I/O a multiple of the physical block size? */ 571 if (t->io_min & (t->physical_block_size - 1)) { 572 t->io_min = t->physical_block_size; 573 t->misaligned = 1; 574 ret = -1; 575 } 576 577 /* Optimal I/O a multiple of the physical block size? */ 578 if (t->io_opt & (t->physical_block_size - 1)) { 579 t->io_opt = 0; 580 t->misaligned = 1; 581 ret = -1; 582 } 583 584 /* chunk_sectors a multiple of the physical block size? */ 585 if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) { 586 t->chunk_sectors = 0; 587 t->misaligned = 1; 588 ret = -1; 589 } 590 591 t->raid_partial_stripes_expensive = 592 max(t->raid_partial_stripes_expensive, 593 b->raid_partial_stripes_expensive); 594 595 /* Find lowest common alignment_offset */ 596 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment) 597 % max(t->physical_block_size, t->io_min); 598 599 /* Verify that new alignment_offset is on a logical block boundary */ 600 if (t->alignment_offset & (t->logical_block_size - 1)) { 601 t->misaligned = 1; 602 ret = -1; 603 } 604 605 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size); 606 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size); 607 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size); 608 609 /* Discard alignment and granularity */ 610 if (b->discard_granularity) { 611 alignment = queue_limit_discard_alignment(b, start); 612 613 if (t->discard_granularity != 0 && 614 t->discard_alignment != alignment) { 615 top = t->discard_granularity + t->discard_alignment; 616 bottom = b->discard_granularity + alignment; 617 618 /* Verify that top and bottom intervals line up */ 619 if ((max(top, bottom) % min(top, bottom)) != 0) 620 t->discard_misaligned = 1; 621 } 622 623 t->max_discard_sectors = min_not_zero(t->max_discard_sectors, 624 b->max_discard_sectors); 625 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors, 626 b->max_hw_discard_sectors); 627 t->discard_granularity = max(t->discard_granularity, 628 b->discard_granularity); 629 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) % 630 t->discard_granularity; 631 } 632 633 t->zoned = max(t->zoned, b->zoned); 634 return ret; 635} 636EXPORT_SYMBOL(blk_stack_limits); 637 638/** 639 * disk_stack_limits - adjust queue limits for stacked drivers 640 * @disk: MD/DM gendisk (top) 641 * @bdev: the underlying block device (bottom) 642 * @offset: offset to beginning of data within component device 643 * 644 * Description: 645 * Merges the limits for a top level gendisk and a bottom level 646 * block_device. 647 */ 648void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 649 sector_t offset) 650{ 651 struct request_queue *t = disk->queue; 652 653 if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits, 654 get_start_sect(bdev) + (offset >> 9)) < 0) { 655 char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE]; 656 657 disk_name(disk, 0, top); 658 bdevname(bdev, bottom); 659 660 printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n", 661 top, bottom); 662 } 663 664 blk_queue_update_readahead(disk->queue); 665} 666EXPORT_SYMBOL(disk_stack_limits); 667 668/** 669 * blk_queue_update_dma_pad - update pad mask 670 * @q: the request queue for the device 671 * @mask: pad mask 672 * 673 * Update dma pad mask. 674 * 675 * Appending pad buffer to a request modifies the last entry of a 676 * scatter list such that it includes the pad buffer. 677 **/ 678void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask) 679{ 680 if (mask > q->dma_pad_mask) 681 q->dma_pad_mask = mask; 682} 683EXPORT_SYMBOL(blk_queue_update_dma_pad); 684 685/** 686 * blk_queue_segment_boundary - set boundary rules for segment merging 687 * @q: the request queue for the device 688 * @mask: the memory boundary mask 689 **/ 690void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask) 691{ 692 if (mask < PAGE_SIZE - 1) { 693 mask = PAGE_SIZE - 1; 694 printk(KERN_INFO "%s: set to minimum %lx\n", 695 __func__, mask); 696 } 697 698 q->limits.seg_boundary_mask = mask; 699} 700EXPORT_SYMBOL(blk_queue_segment_boundary); 701 702/** 703 * blk_queue_virt_boundary - set boundary rules for bio merging 704 * @q: the request queue for the device 705 * @mask: the memory boundary mask 706 **/ 707void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask) 708{ 709 q->limits.virt_boundary_mask = mask; 710 711 /* 712 * Devices that require a virtual boundary do not support scatter/gather 713 * I/O natively, but instead require a descriptor list entry for each 714 * page (which might not be idential to the Linux PAGE_SIZE). Because 715 * of that they are not limited by our notion of "segment size". 716 */ 717 if (mask) 718 q->limits.max_segment_size = UINT_MAX; 719} 720EXPORT_SYMBOL(blk_queue_virt_boundary); 721 722/** 723 * blk_queue_dma_alignment - set dma length and memory alignment 724 * @q: the request queue for the device 725 * @mask: alignment mask 726 * 727 * description: 728 * set required memory and length alignment for direct dma transactions. 729 * this is used when building direct io requests for the queue. 730 * 731 **/ 732void blk_queue_dma_alignment(struct request_queue *q, int mask) 733{ 734 q->dma_alignment = mask; 735} 736EXPORT_SYMBOL(blk_queue_dma_alignment); 737 738/** 739 * blk_queue_update_dma_alignment - update dma length and memory alignment 740 * @q: the request queue for the device 741 * @mask: alignment mask 742 * 743 * description: 744 * update required memory and length alignment for direct dma transactions. 745 * If the requested alignment is larger than the current alignment, then 746 * the current queue alignment is updated to the new value, otherwise it 747 * is left alone. The design of this is to allow multiple objects 748 * (driver, device, transport etc) to set their respective 749 * alignments without having them interfere. 750 * 751 **/ 752void blk_queue_update_dma_alignment(struct request_queue *q, int mask) 753{ 754 BUG_ON(mask > PAGE_SIZE); 755 756 if (mask > q->dma_alignment) 757 q->dma_alignment = mask; 758} 759EXPORT_SYMBOL(blk_queue_update_dma_alignment); 760 761/** 762 * blk_set_queue_depth - tell the block layer about the device queue depth 763 * @q: the request queue for the device 764 * @depth: queue depth 765 * 766 */ 767void blk_set_queue_depth(struct request_queue *q, unsigned int depth) 768{ 769 q->queue_depth = depth; 770 rq_qos_queue_depth_changed(q); 771} 772EXPORT_SYMBOL(blk_set_queue_depth); 773 774/** 775 * blk_queue_write_cache - configure queue's write cache 776 * @q: the request queue for the device 777 * @wc: write back cache on or off 778 * @fua: device supports FUA writes, if true 779 * 780 * Tell the block layer about the write cache of @q. 781 */ 782void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua) 783{ 784 if (wc) 785 blk_queue_flag_set(QUEUE_FLAG_WC, q); 786 else 787 blk_queue_flag_clear(QUEUE_FLAG_WC, q); 788 if (fua) 789 blk_queue_flag_set(QUEUE_FLAG_FUA, q); 790 else 791 blk_queue_flag_clear(QUEUE_FLAG_FUA, q); 792 793 wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags)); 794} 795EXPORT_SYMBOL_GPL(blk_queue_write_cache); 796 797/** 798 * blk_queue_required_elevator_features - Set a queue required elevator features 799 * @q: the request queue for the target device 800 * @features: Required elevator features OR'ed together 801 * 802 * Tell the block layer that for the device controlled through @q, only the 803 * only elevators that can be used are those that implement at least the set of 804 * features specified by @features. 805 */ 806void blk_queue_required_elevator_features(struct request_queue *q, 807 unsigned int features) 808{ 809 q->required_elevator_features = features; 810} 811EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features); 812 813/** 814 * blk_queue_can_use_dma_map_merging - configure queue for merging segments. 815 * @q: the request queue for the device 816 * @dev: the device pointer for dma 817 * 818 * Tell the block layer about merging the segments by dma map of @q. 819 */ 820bool blk_queue_can_use_dma_map_merging(struct request_queue *q, 821 struct device *dev) 822{ 823 unsigned long boundary = dma_get_merge_boundary(dev); 824 825 if (!boundary) 826 return false; 827 828 /* No need to update max_segment_size. see blk_queue_virt_boundary() */ 829 blk_queue_virt_boundary(q, boundary); 830 831 return true; 832} 833EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging); 834 835/** 836 * blk_queue_set_zoned - configure a disk queue zoned model. 837 * @disk: the gendisk of the queue to configure 838 * @model: the zoned model to set 839 * 840 * Set the zoned model of the request queue of @disk according to @model. 841 * When @model is BLK_ZONED_HM (host managed), this should be called only 842 * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option). 843 * If @model specifies BLK_ZONED_HA (host aware), the effective model used 844 * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions 845 * on the disk. 846 */ 847void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model) 848{ 849 switch (model) { 850 case BLK_ZONED_HM: 851 /* 852 * Host managed devices are supported only if 853 * CONFIG_BLK_DEV_ZONED is enabled. 854 */ 855 WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED)); 856 break; 857 case BLK_ZONED_HA: 858 /* 859 * Host aware devices can be treated either as regular block 860 * devices (similar to drive managed devices) or as zoned block 861 * devices to take advantage of the zone command set, similarly 862 * to host managed devices. We try the latter if there are no 863 * partitions and zoned block device support is enabled, else 864 * we do nothing special as far as the block layer is concerned. 865 */ 866 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || 867 disk_has_partitions(disk)) 868 model = BLK_ZONED_NONE; 869 break; 870 case BLK_ZONED_NONE: 871 default: 872 if (WARN_ON_ONCE(model != BLK_ZONED_NONE)) 873 model = BLK_ZONED_NONE; 874 break; 875 } 876 877 disk->queue->limits.zoned = model; 878} 879EXPORT_SYMBOL_GPL(blk_queue_set_zoned); 880 881static int __init blk_settings_init(void) 882{ 883 blk_max_low_pfn = max_low_pfn - 1; 884 blk_max_pfn = max_pfn - 1; 885 return 0; 886} 887subsys_initcall(blk_settings_init); 888