summaryrefslogtreecommitdiffstats
path: root/block/blk-settings.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--block/blk-settings.c981
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);