diff options
Diffstat (limited to 'block/blk-settings.c')
| -rw-r--r-- | block/blk-settings.c | 981 |
1 files changed, 981 insertions, 0 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c new file mode 100644 index 000000000..bbca4ce77 --- /dev/null +++ b/block/blk-settings.c @@ -0,0 +1,981 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Functions related to setting various queue properties from drivers + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/pagemap.h> +#include <linux/backing-dev-defs.h> +#include <linux/gcd.h> +#include <linux/lcm.h> +#include <linux/jiffies.h> +#include <linux/gfp.h> +#include <linux/dma-mapping.h> + +#include "blk.h" +#include "blk-wbt.h" + +void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) +{ + q->rq_timeout = timeout; +} +EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); + +/** + * blk_set_default_limits - reset limits to default values + * @lim: the queue_limits structure to reset + * + * Description: + * Returns a queue_limit struct to its default state. + */ +void blk_set_default_limits(struct queue_limits *lim) +{ + lim->max_segments = BLK_MAX_SEGMENTS; + lim->max_discard_segments = 1; + lim->max_integrity_segments = 0; + lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; + lim->virt_boundary_mask = 0; + lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; + lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; + lim->max_dev_sectors = 0; + lim->chunk_sectors = 0; + lim->max_write_zeroes_sectors = 0; + lim->max_zone_append_sectors = 0; + lim->max_discard_sectors = 0; + lim->max_hw_discard_sectors = 0; + lim->max_secure_erase_sectors = 0; + lim->discard_granularity = 0; + lim->discard_alignment = 0; + lim->discard_misaligned = 0; + lim->logical_block_size = lim->physical_block_size = lim->io_min = 512; + lim->bounce = BLK_BOUNCE_NONE; + lim->alignment_offset = 0; + lim->io_opt = 0; + lim->misaligned = 0; + lim->zoned = BLK_ZONED_NONE; + lim->zone_write_granularity = 0; + lim->dma_alignment = 511; +} + +/** + * blk_set_stacking_limits - set default limits for stacking devices + * @lim: the queue_limits structure to reset + * + * Description: + * Returns a queue_limit struct to its default state. Should be used + * by stacking drivers like DM that have no internal limits. + */ +void blk_set_stacking_limits(struct queue_limits *lim) +{ + blk_set_default_limits(lim); + + /* Inherit limits from component devices */ + lim->max_segments = USHRT_MAX; + lim->max_discard_segments = USHRT_MAX; + lim->max_hw_sectors = UINT_MAX; + lim->max_segment_size = UINT_MAX; + lim->max_sectors = UINT_MAX; + lim->max_dev_sectors = UINT_MAX; + lim->max_write_zeroes_sectors = UINT_MAX; + lim->max_zone_append_sectors = UINT_MAX; +} +EXPORT_SYMBOL(blk_set_stacking_limits); + +/** + * blk_queue_bounce_limit - set bounce buffer limit for queue + * @q: the request queue for the device + * @bounce: bounce limit to enforce + * + * Description: + * Force bouncing for ISA DMA ranges or highmem. + * + * DEPRECATED, don't use in new code. + **/ +void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce bounce) +{ + q->limits.bounce = bounce; +} +EXPORT_SYMBOL(blk_queue_bounce_limit); + +/** + * blk_queue_max_hw_sectors - set max sectors for a request for this queue + * @q: the request queue for the device + * @max_hw_sectors: max hardware sectors in the usual 512b unit + * + * Description: + * Enables a low level driver to set a hard upper limit, + * max_hw_sectors, on the size of requests. max_hw_sectors is set by + * the device driver based upon the capabilities of the I/O + * controller. + * + * max_dev_sectors is a hard limit imposed by the storage device for + * READ/WRITE requests. It is set by the disk driver. + * + * max_sectors is a soft limit imposed by the block layer for + * filesystem type requests. This value can be overridden on a + * per-device basis in /sys/block/<device>/queue/max_sectors_kb. + * The soft limit can not exceed max_hw_sectors. + **/ +void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors) +{ + struct queue_limits *limits = &q->limits; + unsigned int max_sectors; + + if ((max_hw_sectors << 9) < PAGE_SIZE) { + max_hw_sectors = 1 << (PAGE_SHIFT - 9); + printk(KERN_INFO "%s: set to minimum %d\n", + __func__, max_hw_sectors); + } + + max_hw_sectors = round_down(max_hw_sectors, + limits->logical_block_size >> SECTOR_SHIFT); + limits->max_hw_sectors = max_hw_sectors; + + max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); + max_sectors = min(max_sectors, BLK_DEF_MAX_SECTORS); + max_sectors = round_down(max_sectors, + limits->logical_block_size >> SECTOR_SHIFT); + limits->max_sectors = max_sectors; + + if (!q->disk) + return; + q->disk->bdi->io_pages = max_sectors >> (PAGE_SHIFT - 9); +} +EXPORT_SYMBOL(blk_queue_max_hw_sectors); + +/** + * blk_queue_chunk_sectors - set size of the chunk for this queue + * @q: the request queue for the device + * @chunk_sectors: chunk sectors in the usual 512b unit + * + * Description: + * If a driver doesn't want IOs to cross a given chunk size, it can set + * this limit and prevent merging across chunks. Note that the block layer + * must accept a page worth of data at any offset. So if the crossing of + * chunks is a hard limitation in the driver, it must still be prepared + * to split single page bios. + **/ +void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors) +{ + q->limits.chunk_sectors = chunk_sectors; +} +EXPORT_SYMBOL(blk_queue_chunk_sectors); + +/** + * blk_queue_max_discard_sectors - set max sectors for a single discard + * @q: the request queue for the device + * @max_discard_sectors: maximum number of sectors to discard + **/ +void blk_queue_max_discard_sectors(struct request_queue *q, + unsigned int max_discard_sectors) +{ + q->limits.max_hw_discard_sectors = max_discard_sectors; + q->limits.max_discard_sectors = max_discard_sectors; +} +EXPORT_SYMBOL(blk_queue_max_discard_sectors); + +/** + * blk_queue_max_secure_erase_sectors - set max sectors for a secure erase + * @q: the request queue for the device + * @max_sectors: maximum number of sectors to secure_erase + **/ +void blk_queue_max_secure_erase_sectors(struct request_queue *q, + unsigned int max_sectors) +{ + q->limits.max_secure_erase_sectors = max_sectors; +} +EXPORT_SYMBOL(blk_queue_max_secure_erase_sectors); + +/** + * blk_queue_max_write_zeroes_sectors - set max sectors for a single + * write zeroes + * @q: the request queue for the device + * @max_write_zeroes_sectors: maximum number of sectors to write per command + **/ +void blk_queue_max_write_zeroes_sectors(struct request_queue *q, + unsigned int max_write_zeroes_sectors) +{ + q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors; +} +EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors); + +/** + * blk_queue_max_zone_append_sectors - set max sectors for a single zone append + * @q: the request queue for the device + * @max_zone_append_sectors: maximum number of sectors to write per command + **/ +void blk_queue_max_zone_append_sectors(struct request_queue *q, + unsigned int max_zone_append_sectors) +{ + unsigned int max_sectors; + + if (WARN_ON(!blk_queue_is_zoned(q))) + return; + + max_sectors = min(q->limits.max_hw_sectors, max_zone_append_sectors); + max_sectors = min(q->limits.chunk_sectors, max_sectors); + + /* + * Signal eventual driver bugs resulting in the max_zone_append sectors limit + * being 0 due to a 0 argument, the chunk_sectors limit (zone size) not set, + * or the max_hw_sectors limit not set. + */ + WARN_ON(!max_sectors); + + q->limits.max_zone_append_sectors = max_sectors; +} +EXPORT_SYMBOL_GPL(blk_queue_max_zone_append_sectors); + +/** + * blk_queue_max_segments - set max hw segments for a request for this queue + * @q: the request queue for the device + * @max_segments: max number of segments + * + * Description: + * Enables a low level driver to set an upper limit on the number of + * hw data segments in a request. + **/ +void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments) +{ + if (!max_segments) { + max_segments = 1; + printk(KERN_INFO "%s: set to minimum %d\n", + __func__, max_segments); + } + + q->limits.max_segments = max_segments; +} +EXPORT_SYMBOL(blk_queue_max_segments); + +/** + * blk_queue_max_discard_segments - set max segments for discard requests + * @q: the request queue for the device + * @max_segments: max number of segments + * + * Description: + * Enables a low level driver to set an upper limit on the number of + * segments in a discard request. + **/ +void blk_queue_max_discard_segments(struct request_queue *q, + unsigned short max_segments) +{ + q->limits.max_discard_segments = max_segments; +} +EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments); + +/** + * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg + * @q: the request queue for the device + * @max_size: max size of segment in bytes + * + * Description: + * Enables a low level driver to set an upper limit on the size of a + * coalesced segment + **/ +void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size) +{ + if (max_size < PAGE_SIZE) { + max_size = PAGE_SIZE; + printk(KERN_INFO "%s: set to minimum %d\n", + __func__, max_size); + } + + /* see blk_queue_virt_boundary() for the explanation */ + WARN_ON_ONCE(q->limits.virt_boundary_mask); + + q->limits.max_segment_size = max_size; +} +EXPORT_SYMBOL(blk_queue_max_segment_size); + +/** + * blk_queue_logical_block_size - set logical block size for the queue + * @q: the request queue for the device + * @size: the logical block size, in bytes + * + * Description: + * This should be set to the lowest possible block size that the + * storage device can address. The default of 512 covers most + * hardware. + **/ +void blk_queue_logical_block_size(struct request_queue *q, unsigned int size) +{ + struct queue_limits *limits = &q->limits; + + limits->logical_block_size = size; + + if (limits->physical_block_size < size) + limits->physical_block_size = size; + + if (limits->io_min < limits->physical_block_size) + limits->io_min = limits->physical_block_size; + + limits->max_hw_sectors = + round_down(limits->max_hw_sectors, size >> SECTOR_SHIFT); + limits->max_sectors = + round_down(limits->max_sectors, size >> SECTOR_SHIFT); +} +EXPORT_SYMBOL(blk_queue_logical_block_size); + +/** + * blk_queue_physical_block_size - set physical block size for the queue + * @q: the request queue for the device + * @size: the physical block size, in bytes + * + * Description: + * This should be set to the lowest possible sector size that the + * hardware can operate on without reverting to read-modify-write + * operations. + */ +void blk_queue_physical_block_size(struct request_queue *q, unsigned int size) +{ + q->limits.physical_block_size = size; + + if (q->limits.physical_block_size < q->limits.logical_block_size) + q->limits.physical_block_size = q->limits.logical_block_size; + + if (q->limits.io_min < q->limits.physical_block_size) + q->limits.io_min = q->limits.physical_block_size; +} +EXPORT_SYMBOL(blk_queue_physical_block_size); + +/** + * blk_queue_zone_write_granularity - set zone write granularity for the queue + * @q: the request queue for the zoned device + * @size: the zone write granularity size, in bytes + * + * Description: + * This should be set to the lowest possible size allowing to write in + * sequential zones of a zoned block device. + */ +void blk_queue_zone_write_granularity(struct request_queue *q, + unsigned int size) +{ + if (WARN_ON_ONCE(!blk_queue_is_zoned(q))) + return; + + q->limits.zone_write_granularity = size; + + if (q->limits.zone_write_granularity < q->limits.logical_block_size) + q->limits.zone_write_granularity = q->limits.logical_block_size; +} +EXPORT_SYMBOL_GPL(blk_queue_zone_write_granularity); + +/** + * blk_queue_alignment_offset - set physical block alignment offset + * @q: the request queue for the device + * @offset: alignment offset in bytes + * + * Description: + * Some devices are naturally misaligned to compensate for things like + * the legacy DOS partition table 63-sector offset. Low-level drivers + * should call this function for devices whose first sector is not + * naturally aligned. + */ +void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) +{ + q->limits.alignment_offset = + offset & (q->limits.physical_block_size - 1); + q->limits.misaligned = 0; +} +EXPORT_SYMBOL(blk_queue_alignment_offset); + +void disk_update_readahead(struct gendisk *disk) +{ + struct request_queue *q = disk->queue; + + /* + * For read-ahead of large files to be effective, we need to read ahead + * at least twice the optimal I/O size. + */ + disk->bdi->ra_pages = + max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES); + disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9); +} +EXPORT_SYMBOL_GPL(disk_update_readahead); + +/** + * blk_limits_io_min - set minimum request size for a device + * @limits: the queue limits + * @min: smallest I/O size in bytes + * + * Description: + * Some devices have an internal block size bigger than the reported + * hardware sector size. This function can be used to signal the + * smallest I/O the device can perform without incurring a performance + * penalty. + */ +void blk_limits_io_min(struct queue_limits *limits, unsigned int min) +{ + limits->io_min = min; + + if (limits->io_min < limits->logical_block_size) + limits->io_min = limits->logical_block_size; + + if (limits->io_min < limits->physical_block_size) + limits->io_min = limits->physical_block_size; +} +EXPORT_SYMBOL(blk_limits_io_min); + +/** + * blk_queue_io_min - set minimum request size for the queue + * @q: the request queue for the device + * @min: smallest I/O size in bytes + * + * Description: + * Storage devices may report a granularity or preferred minimum I/O + * size which is the smallest request the device can perform without + * incurring a performance penalty. For disk drives this is often the + * physical block size. For RAID arrays it is often the stripe chunk + * size. A properly aligned multiple of minimum_io_size is the + * preferred request size for workloads where a high number of I/O + * operations is desired. + */ +void blk_queue_io_min(struct request_queue *q, unsigned int min) +{ + blk_limits_io_min(&q->limits, min); +} +EXPORT_SYMBOL(blk_queue_io_min); + +/** + * blk_limits_io_opt - set optimal request size for a device + * @limits: the queue limits + * @opt: smallest I/O size in bytes + * + * Description: + * Storage devices may report an optimal I/O size, which is the + * device's preferred unit for sustained I/O. This is rarely reported + * for disk drives. For RAID arrays it is usually the stripe width or + * the internal track size. A properly aligned multiple of + * optimal_io_size is the preferred request size for workloads where + * sustained throughput is desired. + */ +void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt) +{ + limits->io_opt = opt; +} +EXPORT_SYMBOL(blk_limits_io_opt); + +/** + * blk_queue_io_opt - set optimal request size for the queue + * @q: the request queue for the device + * @opt: optimal request size in bytes + * + * Description: + * Storage devices may report an optimal I/O size, which is the + * device's preferred unit for sustained I/O. This is rarely reported + * for disk drives. For RAID arrays it is usually the stripe width or + * the internal track size. A properly aligned multiple of + * optimal_io_size is the preferred request size for workloads where + * sustained throughput is desired. + */ +void blk_queue_io_opt(struct request_queue *q, unsigned int opt) +{ + blk_limits_io_opt(&q->limits, opt); + if (!q->disk) + return; + q->disk->bdi->ra_pages = + max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES); +} +EXPORT_SYMBOL(blk_queue_io_opt); + +static int queue_limit_alignment_offset(struct queue_limits *lim, + sector_t sector) +{ + unsigned int granularity = max(lim->physical_block_size, lim->io_min); + unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT) + << SECTOR_SHIFT; + + return (granularity + lim->alignment_offset - alignment) % granularity; +} + +static unsigned int queue_limit_discard_alignment(struct queue_limits *lim, + sector_t sector) +{ + unsigned int alignment, granularity, offset; + + if (!lim->max_discard_sectors) + return 0; + + /* Why are these in bytes, not sectors? */ + alignment = lim->discard_alignment >> SECTOR_SHIFT; + granularity = lim->discard_granularity >> SECTOR_SHIFT; + if (!granularity) + return 0; + + /* Offset of the partition start in 'granularity' sectors */ + offset = sector_div(sector, granularity); + + /* And why do we do this modulus *again* in blkdev_issue_discard()? */ + offset = (granularity + alignment - offset) % granularity; + + /* Turn it back into bytes, gaah */ + return offset << SECTOR_SHIFT; +} + +static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs) +{ + sectors = round_down(sectors, lbs >> SECTOR_SHIFT); + if (sectors < PAGE_SIZE >> SECTOR_SHIFT) + sectors = PAGE_SIZE >> SECTOR_SHIFT; + return sectors; +} + +/** + * blk_stack_limits - adjust queue_limits for stacked devices + * @t: the stacking driver limits (top device) + * @b: the underlying queue limits (bottom, component device) + * @start: first data sector within component device + * + * Description: + * This function is used by stacking drivers like MD and DM to ensure + * that all component devices have compatible block sizes and + * alignments. The stacking driver must provide a queue_limits + * struct (top) and then iteratively call the stacking function for + * all component (bottom) devices. The stacking function will + * attempt to combine the values and ensure proper alignment. + * + * Returns 0 if the top and bottom queue_limits are compatible. The + * top device's block sizes and alignment offsets may be adjusted to + * ensure alignment with the bottom device. If no compatible sizes + * and alignments exist, -1 is returned and the resulting top + * queue_limits will have the misaligned flag set to indicate that + * the alignment_offset is undefined. + */ +int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, + sector_t start) +{ + unsigned int top, bottom, alignment, ret = 0; + + t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); + t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); + t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); + t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, + b->max_write_zeroes_sectors); + t->max_zone_append_sectors = min(t->max_zone_append_sectors, + b->max_zone_append_sectors); + t->bounce = max(t->bounce, b->bounce); + + t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, + b->seg_boundary_mask); + t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, + b->virt_boundary_mask); + + t->max_segments = min_not_zero(t->max_segments, b->max_segments); + t->max_discard_segments = min_not_zero(t->max_discard_segments, + b->max_discard_segments); + t->max_integrity_segments = min_not_zero(t->max_integrity_segments, + b->max_integrity_segments); + + t->max_segment_size = min_not_zero(t->max_segment_size, + b->max_segment_size); + + t->misaligned |= b->misaligned; + + alignment = queue_limit_alignment_offset(b, start); + + /* Bottom device has different alignment. Check that it is + * compatible with the current top alignment. + */ + if (t->alignment_offset != alignment) { + + top = max(t->physical_block_size, t->io_min) + + t->alignment_offset; + bottom = max(b->physical_block_size, b->io_min) + alignment; + + /* Verify that top and bottom intervals line up */ + if (max(top, bottom) % min(top, bottom)) { + t->misaligned = 1; + ret = -1; + } + } + + t->logical_block_size = max(t->logical_block_size, + b->logical_block_size); + + t->physical_block_size = max(t->physical_block_size, + b->physical_block_size); + + t->io_min = max(t->io_min, b->io_min); + t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); + t->dma_alignment = max(t->dma_alignment, b->dma_alignment); + + /* Set non-power-of-2 compatible chunk_sectors boundary */ + if (b->chunk_sectors) + t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors); + + /* Physical block size a multiple of the logical block size? */ + if (t->physical_block_size & (t->logical_block_size - 1)) { + t->physical_block_size = t->logical_block_size; + t->misaligned = 1; + ret = -1; + } + + /* Minimum I/O a multiple of the physical block size? */ + if (t->io_min & (t->physical_block_size - 1)) { + t->io_min = t->physical_block_size; + t->misaligned = 1; + ret = -1; + } + + /* Optimal I/O a multiple of the physical block size? */ + if (t->io_opt & (t->physical_block_size - 1)) { + t->io_opt = 0; + t->misaligned = 1; + ret = -1; + } + + /* chunk_sectors a multiple of the physical block size? */ + if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) { + t->chunk_sectors = 0; + t->misaligned = 1; + ret = -1; + } + + t->raid_partial_stripes_expensive = + max(t->raid_partial_stripes_expensive, + b->raid_partial_stripes_expensive); + + /* Find lowest common alignment_offset */ + t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment) + % max(t->physical_block_size, t->io_min); + + /* Verify that new alignment_offset is on a logical block boundary */ + if (t->alignment_offset & (t->logical_block_size - 1)) { + t->misaligned = 1; + ret = -1; + } + + t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size); + t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size); + t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size); + + /* Discard alignment and granularity */ + if (b->discard_granularity) { + alignment = queue_limit_discard_alignment(b, start); + + if (t->discard_granularity != 0 && + t->discard_alignment != alignment) { + top = t->discard_granularity + t->discard_alignment; + bottom = b->discard_granularity + alignment; + + /* Verify that top and bottom intervals line up */ + if ((max(top, bottom) % min(top, bottom)) != 0) + t->discard_misaligned = 1; + } + + t->max_discard_sectors = min_not_zero(t->max_discard_sectors, + b->max_discard_sectors); + t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors, + b->max_hw_discard_sectors); + t->discard_granularity = max(t->discard_granularity, + b->discard_granularity); + t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) % + t->discard_granularity; + } + t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors, + b->max_secure_erase_sectors); + t->zone_write_granularity = max(t->zone_write_granularity, + b->zone_write_granularity); + t->zoned = max(t->zoned, b->zoned); + return ret; +} +EXPORT_SYMBOL(blk_stack_limits); + +/** + * disk_stack_limits - adjust queue limits for stacked drivers + * @disk: MD/DM gendisk (top) + * @bdev: the underlying block device (bottom) + * @offset: offset to beginning of data within component device + * + * Description: + * Merges the limits for a top level gendisk and a bottom level + * block_device. + */ +void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, + sector_t offset) +{ + struct request_queue *t = disk->queue; + + if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits, + get_start_sect(bdev) + (offset >> 9)) < 0) + pr_notice("%s: Warning: Device %pg is misaligned\n", + disk->disk_name, bdev); + + disk_update_readahead(disk); +} +EXPORT_SYMBOL(disk_stack_limits); + +/** + * blk_queue_update_dma_pad - update pad mask + * @q: the request queue for the device + * @mask: pad mask + * + * Update dma pad mask. + * + * Appending pad buffer to a request modifies the last entry of a + * scatter list such that it includes the pad buffer. + **/ +void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask) +{ + if (mask > q->dma_pad_mask) + q->dma_pad_mask = mask; +} +EXPORT_SYMBOL(blk_queue_update_dma_pad); + +/** + * blk_queue_segment_boundary - set boundary rules for segment merging + * @q: the request queue for the device + * @mask: the memory boundary mask + **/ +void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask) +{ + if (mask < PAGE_SIZE - 1) { + mask = PAGE_SIZE - 1; + printk(KERN_INFO "%s: set to minimum %lx\n", + __func__, mask); + } + + q->limits.seg_boundary_mask = mask; +} +EXPORT_SYMBOL(blk_queue_segment_boundary); + +/** + * blk_queue_virt_boundary - set boundary rules for bio merging + * @q: the request queue for the device + * @mask: the memory boundary mask + **/ +void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask) +{ + q->limits.virt_boundary_mask = mask; + + /* + * Devices that require a virtual boundary do not support scatter/gather + * I/O natively, but instead require a descriptor list entry for each + * page (which might not be idential to the Linux PAGE_SIZE). Because + * of that they are not limited by our notion of "segment size". + */ + if (mask) + q->limits.max_segment_size = UINT_MAX; +} +EXPORT_SYMBOL(blk_queue_virt_boundary); + +/** + * blk_queue_dma_alignment - set dma length and memory alignment + * @q: the request queue for the device + * @mask: alignment mask + * + * description: + * set required memory and length alignment for direct dma transactions. + * this is used when building direct io requests for the queue. + * + **/ +void blk_queue_dma_alignment(struct request_queue *q, int mask) +{ + q->limits.dma_alignment = mask; +} +EXPORT_SYMBOL(blk_queue_dma_alignment); + +/** + * blk_queue_update_dma_alignment - update dma length and memory alignment + * @q: the request queue for the device + * @mask: alignment mask + * + * description: + * update required memory and length alignment for direct dma transactions. + * If the requested alignment is larger than the current alignment, then + * the current queue alignment is updated to the new value, otherwise it + * is left alone. The design of this is to allow multiple objects + * (driver, device, transport etc) to set their respective + * alignments without having them interfere. + * + **/ +void blk_queue_update_dma_alignment(struct request_queue *q, int mask) +{ + BUG_ON(mask > PAGE_SIZE); + + if (mask > q->limits.dma_alignment) + q->limits.dma_alignment = mask; +} +EXPORT_SYMBOL(blk_queue_update_dma_alignment); + +/** + * blk_set_queue_depth - tell the block layer about the device queue depth + * @q: the request queue for the device + * @depth: queue depth + * + */ +void blk_set_queue_depth(struct request_queue *q, unsigned int depth) +{ + q->queue_depth = depth; + rq_qos_queue_depth_changed(q); +} +EXPORT_SYMBOL(blk_set_queue_depth); + +/** + * blk_queue_write_cache - configure queue's write cache + * @q: the request queue for the device + * @wc: write back cache on or off + * @fua: device supports FUA writes, if true + * + * Tell the block layer about the write cache of @q. + */ +void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua) +{ + if (wc) { + blk_queue_flag_set(QUEUE_FLAG_HW_WC, q); + blk_queue_flag_set(QUEUE_FLAG_WC, q); + } else { + blk_queue_flag_clear(QUEUE_FLAG_HW_WC, q); + blk_queue_flag_clear(QUEUE_FLAG_WC, q); + } + if (fua) + blk_queue_flag_set(QUEUE_FLAG_FUA, q); + else + blk_queue_flag_clear(QUEUE_FLAG_FUA, q); + + wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags)); +} +EXPORT_SYMBOL_GPL(blk_queue_write_cache); + +/** + * blk_queue_required_elevator_features - Set a queue required elevator features + * @q: the request queue for the target device + * @features: Required elevator features OR'ed together + * + * Tell the block layer that for the device controlled through @q, only the + * only elevators that can be used are those that implement at least the set of + * features specified by @features. + */ +void blk_queue_required_elevator_features(struct request_queue *q, + unsigned int features) +{ + q->required_elevator_features = features; +} +EXPORT_SYMBOL_GPL(blk_queue_required_elevator_features); + +/** + * blk_queue_can_use_dma_map_merging - configure queue for merging segments. + * @q: the request queue for the device + * @dev: the device pointer for dma + * + * Tell the block layer about merging the segments by dma map of @q. + */ +bool blk_queue_can_use_dma_map_merging(struct request_queue *q, + struct device *dev) +{ + unsigned long boundary = dma_get_merge_boundary(dev); + + if (!boundary) + return false; + + /* No need to update max_segment_size. see blk_queue_virt_boundary() */ + blk_queue_virt_boundary(q, boundary); + + return true; +} +EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging); + +static bool disk_has_partitions(struct gendisk *disk) +{ + unsigned long idx; + struct block_device *part; + bool ret = false; + + rcu_read_lock(); + xa_for_each(&disk->part_tbl, idx, part) { + if (bdev_is_partition(part)) { + ret = true; + break; + } + } + rcu_read_unlock(); + + return ret; +} + +/** + * disk_set_zoned - configure the zoned model for a disk + * @disk: the gendisk of the queue to configure + * @model: the zoned model to set + * + * Set the zoned model of @disk to @model. + * + * When @model is BLK_ZONED_HM (host managed), this should be called only + * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option). + * If @model specifies BLK_ZONED_HA (host aware), the effective model used + * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions + * on the disk. + */ +void disk_set_zoned(struct gendisk *disk, enum blk_zoned_model model) +{ + struct request_queue *q = disk->queue; + unsigned int old_model = q->limits.zoned; + + switch (model) { + case BLK_ZONED_HM: + /* + * Host managed devices are supported only if + * CONFIG_BLK_DEV_ZONED is enabled. + */ + WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED)); + break; + case BLK_ZONED_HA: + /* + * Host aware devices can be treated either as regular block + * devices (similar to drive managed devices) or as zoned block + * devices to take advantage of the zone command set, similarly + * to host managed devices. We try the latter if there are no + * partitions and zoned block device support is enabled, else + * we do nothing special as far as the block layer is concerned. + */ + if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || + disk_has_partitions(disk)) + model = BLK_ZONED_NONE; + break; + case BLK_ZONED_NONE: + default: + if (WARN_ON_ONCE(model != BLK_ZONED_NONE)) + model = BLK_ZONED_NONE; + break; + } + + q->limits.zoned = model; + if (model != BLK_ZONED_NONE) { + /* + * Set the zone write granularity to the device logical block + * size by default. The driver can change this value if needed. + */ + blk_queue_zone_write_granularity(q, + queue_logical_block_size(q)); + } else if (old_model != BLK_ZONED_NONE) { + disk_clear_zone_settings(disk); + } +} +EXPORT_SYMBOL_GPL(disk_set_zoned); + +int bdev_alignment_offset(struct block_device *bdev) +{ + struct request_queue *q = bdev_get_queue(bdev); + + if (q->limits.misaligned) + return -1; + if (bdev_is_partition(bdev)) + return queue_limit_alignment_offset(&q->limits, + bdev->bd_start_sect); + return q->limits.alignment_offset; +} +EXPORT_SYMBOL_GPL(bdev_alignment_offset); + +unsigned int bdev_discard_alignment(struct block_device *bdev) +{ + struct request_queue *q = bdev_get_queue(bdev); + + if (bdev_is_partition(bdev)) + return queue_limit_discard_alignment(&q->limits, + bdev->bd_start_sect); + return q->limits.discard_alignment; +} +EXPORT_SYMBOL_GPL(bdev_discard_alignment); |