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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Jens Axboe](/assets/img/avatar_default.png)
Now that we converted everything to the newer block write cache interface, kill off the queue flush_flags and queueable flush entries. Signed-off-by: Jens Axboe <axboe@fb.com>
863 lines
27 KiB
C
863 lines
27 KiB
C
/*
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* Functions related to setting various queue properties from drivers
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/bootmem.h> /* for max_pfn/max_low_pfn */
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#include <linux/gcd.h>
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#include <linux/lcm.h>
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#include <linux/jiffies.h>
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#include <linux/gfp.h>
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#include "blk.h"
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unsigned long blk_max_low_pfn;
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EXPORT_SYMBOL(blk_max_low_pfn);
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unsigned long blk_max_pfn;
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/**
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* blk_queue_prep_rq - set a prepare_request function for queue
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* @q: queue
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* @pfn: prepare_request function
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*
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* It's possible for a queue to register a prepare_request callback which
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* is invoked before the request is handed to the request_fn. The goal of
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* the function is to prepare a request for I/O, it can be used to build a
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* cdb from the request data for instance.
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*
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*/
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void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn)
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{
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q->prep_rq_fn = pfn;
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}
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EXPORT_SYMBOL(blk_queue_prep_rq);
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/**
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* blk_queue_unprep_rq - set an unprepare_request function for queue
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* @q: queue
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* @ufn: unprepare_request function
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*
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* It's possible for a queue to register an unprepare_request callback
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* which is invoked before the request is finally completed. The goal
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* of the function is to deallocate any data that was allocated in the
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* prepare_request callback.
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*
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*/
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void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn)
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{
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q->unprep_rq_fn = ufn;
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}
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EXPORT_SYMBOL(blk_queue_unprep_rq);
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void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn)
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{
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q->softirq_done_fn = fn;
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}
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EXPORT_SYMBOL(blk_queue_softirq_done);
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void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
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{
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q->rq_timeout = timeout;
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}
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EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
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void blk_queue_rq_timed_out(struct request_queue *q, rq_timed_out_fn *fn)
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{
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q->rq_timed_out_fn = fn;
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}
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EXPORT_SYMBOL_GPL(blk_queue_rq_timed_out);
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void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn)
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{
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q->lld_busy_fn = fn;
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}
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EXPORT_SYMBOL_GPL(blk_queue_lld_busy);
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/**
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* blk_set_default_limits - reset limits to default values
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* @lim: the queue_limits structure to reset
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*
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* Description:
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* Returns a queue_limit struct to its default state.
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*/
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void blk_set_default_limits(struct queue_limits *lim)
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{
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lim->max_segments = BLK_MAX_SEGMENTS;
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lim->max_integrity_segments = 0;
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lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
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lim->virt_boundary_mask = 0;
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lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
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lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
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lim->max_dev_sectors = 0;
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lim->chunk_sectors = 0;
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lim->max_write_same_sectors = 0;
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lim->max_discard_sectors = 0;
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lim->max_hw_discard_sectors = 0;
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lim->discard_granularity = 0;
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lim->discard_alignment = 0;
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lim->discard_misaligned = 0;
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lim->discard_zeroes_data = 0;
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lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
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lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
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lim->alignment_offset = 0;
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lim->io_opt = 0;
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lim->misaligned = 0;
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lim->cluster = 1;
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}
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EXPORT_SYMBOL(blk_set_default_limits);
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/**
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* blk_set_stacking_limits - set default limits for stacking devices
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* @lim: the queue_limits structure to reset
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*
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* Description:
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* Returns a queue_limit struct to its default state. Should be used
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* by stacking drivers like DM that have no internal limits.
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*/
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void blk_set_stacking_limits(struct queue_limits *lim)
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{
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blk_set_default_limits(lim);
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/* Inherit limits from component devices */
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lim->discard_zeroes_data = 1;
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lim->max_segments = USHRT_MAX;
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lim->max_hw_sectors = UINT_MAX;
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lim->max_segment_size = UINT_MAX;
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lim->max_sectors = UINT_MAX;
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lim->max_dev_sectors = UINT_MAX;
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lim->max_write_same_sectors = UINT_MAX;
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}
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EXPORT_SYMBOL(blk_set_stacking_limits);
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/**
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* blk_queue_make_request - define an alternate make_request function for a device
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* @q: the request queue for the device to be affected
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* @mfn: the alternate make_request function
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*
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* Description:
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* The normal way for &struct bios to be passed to a device
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* driver is for them to be collected into requests on a request
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* queue, and then to allow the device driver to select requests
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* off that queue when it is ready. This works well for many block
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* devices. However some block devices (typically virtual devices
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* such as md or lvm) do not benefit from the processing on the
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* request queue, and are served best by having the requests passed
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* directly to them. This can be achieved by providing a function
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* to blk_queue_make_request().
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*
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* Caveat:
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* The driver that does this *must* be able to deal appropriately
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* with buffers in "highmemory". This can be accomplished by either calling
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* __bio_kmap_atomic() to get a temporary kernel mapping, or by calling
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* blk_queue_bounce() to create a buffer in normal memory.
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**/
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void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
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{
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/*
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* set defaults
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*/
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q->nr_requests = BLKDEV_MAX_RQ;
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q->make_request_fn = mfn;
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blk_queue_dma_alignment(q, 511);
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blk_queue_congestion_threshold(q);
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q->nr_batching = BLK_BATCH_REQ;
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blk_set_default_limits(&q->limits);
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/*
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* by default assume old behaviour and bounce for any highmem page
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*/
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blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
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}
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EXPORT_SYMBOL(blk_queue_make_request);
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/**
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* blk_queue_bounce_limit - set bounce buffer limit for queue
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* @q: the request queue for the device
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* @max_addr: the maximum address the device can handle
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*
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* Description:
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* Different hardware can have different requirements as to what pages
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* it can do I/O directly to. A low level driver can call
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* blk_queue_bounce_limit to have lower memory pages allocated as bounce
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* buffers for doing I/O to pages residing above @max_addr.
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**/
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void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr)
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{
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unsigned long b_pfn = max_addr >> PAGE_SHIFT;
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int dma = 0;
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q->bounce_gfp = GFP_NOIO;
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#if BITS_PER_LONG == 64
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/*
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* Assume anything <= 4GB can be handled by IOMMU. Actually
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* some IOMMUs can handle everything, but I don't know of a
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* way to test this here.
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*/
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if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
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dma = 1;
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q->limits.bounce_pfn = max(max_low_pfn, b_pfn);
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#else
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if (b_pfn < blk_max_low_pfn)
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dma = 1;
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q->limits.bounce_pfn = b_pfn;
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#endif
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if (dma) {
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init_emergency_isa_pool();
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q->bounce_gfp = GFP_NOIO | GFP_DMA;
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q->limits.bounce_pfn = b_pfn;
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}
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}
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EXPORT_SYMBOL(blk_queue_bounce_limit);
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/**
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* blk_queue_max_hw_sectors - set max sectors for a request for this queue
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* @q: the request queue for the device
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* @max_hw_sectors: max hardware sectors in the usual 512b unit
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*
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* Description:
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* Enables a low level driver to set a hard upper limit,
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* max_hw_sectors, on the size of requests. max_hw_sectors is set by
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* the device driver based upon the capabilities of the I/O
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* controller.
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*
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* max_dev_sectors is a hard limit imposed by the storage device for
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* READ/WRITE requests. It is set by the disk driver.
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*
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* max_sectors is a soft limit imposed by the block layer for
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* filesystem type requests. This value can be overridden on a
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* per-device basis in /sys/block/<device>/queue/max_sectors_kb.
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* The soft limit can not exceed max_hw_sectors.
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**/
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void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
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{
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struct queue_limits *limits = &q->limits;
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unsigned int max_sectors;
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if ((max_hw_sectors << 9) < PAGE_SIZE) {
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max_hw_sectors = 1 << (PAGE_SHIFT - 9);
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printk(KERN_INFO "%s: set to minimum %d\n",
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__func__, max_hw_sectors);
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}
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limits->max_hw_sectors = max_hw_sectors;
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max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
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max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
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limits->max_sectors = max_sectors;
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}
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EXPORT_SYMBOL(blk_queue_max_hw_sectors);
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/**
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* blk_queue_chunk_sectors - set size of the chunk for this queue
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* @q: the request queue for the device
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* @chunk_sectors: chunk sectors in the usual 512b unit
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*
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* Description:
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* If a driver doesn't want IOs to cross a given chunk size, it can set
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* this limit and prevent merging across chunks. Note that the chunk size
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* must currently be a power-of-2 in sectors. Also note that the block
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* layer must accept a page worth of data at any offset. So if the
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* crossing of chunks is a hard limitation in the driver, it must still be
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* prepared to split single page bios.
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**/
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void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
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{
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BUG_ON(!is_power_of_2(chunk_sectors));
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q->limits.chunk_sectors = chunk_sectors;
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}
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EXPORT_SYMBOL(blk_queue_chunk_sectors);
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/**
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* blk_queue_max_discard_sectors - set max sectors for a single discard
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* @q: the request queue for the device
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* @max_discard_sectors: maximum number of sectors to discard
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**/
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void blk_queue_max_discard_sectors(struct request_queue *q,
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unsigned int max_discard_sectors)
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{
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q->limits.max_hw_discard_sectors = max_discard_sectors;
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q->limits.max_discard_sectors = max_discard_sectors;
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}
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EXPORT_SYMBOL(blk_queue_max_discard_sectors);
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/**
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* blk_queue_max_write_same_sectors - set max sectors for a single write same
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* @q: the request queue for the device
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* @max_write_same_sectors: maximum number of sectors to write per command
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**/
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void blk_queue_max_write_same_sectors(struct request_queue *q,
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unsigned int max_write_same_sectors)
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{
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q->limits.max_write_same_sectors = max_write_same_sectors;
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}
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EXPORT_SYMBOL(blk_queue_max_write_same_sectors);
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/**
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* blk_queue_max_segments - set max hw segments for a request for this queue
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* @q: the request queue for the device
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* @max_segments: max number of segments
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*
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* Description:
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* Enables a low level driver to set an upper limit on the number of
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* hw data segments in a request.
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**/
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void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
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{
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if (!max_segments) {
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max_segments = 1;
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printk(KERN_INFO "%s: set to minimum %d\n",
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__func__, max_segments);
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}
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q->limits.max_segments = max_segments;
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}
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EXPORT_SYMBOL(blk_queue_max_segments);
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/**
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* blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
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* @q: the request queue for the device
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* @max_size: max size of segment in bytes
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*
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* Description:
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* Enables a low level driver to set an upper limit on the size of a
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* coalesced segment
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**/
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void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
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{
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if (max_size < PAGE_SIZE) {
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max_size = PAGE_SIZE;
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printk(KERN_INFO "%s: set to minimum %d\n",
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__func__, max_size);
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}
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q->limits.max_segment_size = max_size;
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}
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EXPORT_SYMBOL(blk_queue_max_segment_size);
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/**
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* blk_queue_logical_block_size - set logical block size for the queue
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* @q: the request queue for the device
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* @size: the logical block size, in bytes
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*
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* Description:
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* This should be set to the lowest possible block size that the
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* storage device can address. The default of 512 covers most
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* hardware.
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**/
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void blk_queue_logical_block_size(struct request_queue *q, unsigned short size)
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{
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q->limits.logical_block_size = size;
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if (q->limits.physical_block_size < size)
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q->limits.physical_block_size = size;
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if (q->limits.io_min < q->limits.physical_block_size)
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q->limits.io_min = q->limits.physical_block_size;
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}
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EXPORT_SYMBOL(blk_queue_logical_block_size);
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/**
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* blk_queue_physical_block_size - set physical block size for the queue
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* @q: the request queue for the device
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* @size: the physical block size, in bytes
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*
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* Description:
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* This should be set to the lowest possible sector size that the
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* hardware can operate on without reverting to read-modify-write
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* operations.
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*/
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void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
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{
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q->limits.physical_block_size = size;
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if (q->limits.physical_block_size < q->limits.logical_block_size)
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q->limits.physical_block_size = q->limits.logical_block_size;
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if (q->limits.io_min < q->limits.physical_block_size)
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q->limits.io_min = q->limits.physical_block_size;
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}
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EXPORT_SYMBOL(blk_queue_physical_block_size);
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/**
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* blk_queue_alignment_offset - set physical block alignment offset
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* @q: the request queue for the device
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* @offset: alignment offset in bytes
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*
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* Description:
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* Some devices are naturally misaligned to compensate for things like
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* the legacy DOS partition table 63-sector offset. Low-level drivers
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* should call this function for devices whose first sector is not
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* naturally aligned.
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*/
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void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
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{
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q->limits.alignment_offset =
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offset & (q->limits.physical_block_size - 1);
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q->limits.misaligned = 0;
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}
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EXPORT_SYMBOL(blk_queue_alignment_offset);
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/**
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* blk_limits_io_min - set minimum request size for a device
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* @limits: the queue limits
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* @min: smallest I/O size in bytes
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*
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* Description:
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* Some devices have an internal block size bigger than the reported
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* hardware sector size. This function can be used to signal the
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* smallest I/O the device can perform without incurring a performance
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* penalty.
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*/
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void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
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{
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limits->io_min = min;
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if (limits->io_min < limits->logical_block_size)
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limits->io_min = limits->logical_block_size;
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if (limits->io_min < limits->physical_block_size)
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limits->io_min = limits->physical_block_size;
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}
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EXPORT_SYMBOL(blk_limits_io_min);
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/**
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* blk_queue_io_min - set minimum request size for the queue
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* @q: the request queue for the device
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* @min: smallest I/O size in bytes
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*
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* Description:
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* Storage devices may report a granularity or preferred minimum I/O
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* size which is the smallest request the device can perform without
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* incurring a performance penalty. For disk drives this is often the
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* physical block size. For RAID arrays it is often the stripe chunk
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* size. A properly aligned multiple of minimum_io_size is the
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* preferred request size for workloads where a high number of I/O
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* operations is desired.
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*/
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void blk_queue_io_min(struct request_queue *q, unsigned int min)
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{
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blk_limits_io_min(&q->limits, min);
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}
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EXPORT_SYMBOL(blk_queue_io_min);
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/**
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* blk_limits_io_opt - set optimal request size for a device
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* @limits: the queue limits
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* @opt: smallest I/O size in bytes
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*
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* Description:
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* Storage devices may report an optimal I/O size, which is the
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* device's preferred unit for sustained I/O. This is rarely reported
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* for disk drives. For RAID arrays it is usually the stripe width or
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* the internal track size. A properly aligned multiple of
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* optimal_io_size is the preferred request size for workloads where
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* sustained throughput is desired.
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*/
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void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
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{
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limits->io_opt = opt;
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}
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EXPORT_SYMBOL(blk_limits_io_opt);
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/**
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* blk_queue_io_opt - set optimal request size for the queue
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* @q: the request queue for the device
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* @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);
|
|
}
|
|
EXPORT_SYMBOL(blk_queue_io_opt);
|
|
|
|
/**
|
|
* blk_queue_stack_limits - inherit underlying queue limits for stacked drivers
|
|
* @t: the stacking driver (top)
|
|
* @b: the underlying device (bottom)
|
|
**/
|
|
void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
|
|
{
|
|
blk_stack_limits(&t->limits, &b->limits, 0);
|
|
}
|
|
EXPORT_SYMBOL(blk_queue_stack_limits);
|
|
|
|
/**
|
|
* 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_same_sectors = min(t->max_write_same_sectors,
|
|
b->max_write_same_sectors);
|
|
t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn);
|
|
|
|
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_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->cluster &= b->cluster;
|
|
t->discard_zeroes_data &= b->discard_zeroes_data;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(blk_stack_limits);
|
|
|
|
/**
|
|
* bdev_stack_limits - adjust queue limits for stacked drivers
|
|
* @t: the stacking driver limits (top device)
|
|
* @bdev: the component block_device (bottom)
|
|
* @start: first data sector within component device
|
|
*
|
|
* Description:
|
|
* Merges queue limits for a top device and a block_device. Returns
|
|
* 0 if alignment didn't change. Returns -1 if adding the bottom
|
|
* device caused misalignment.
|
|
*/
|
|
int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
|
|
sector_t start)
|
|
{
|
|
struct request_queue *bq = bdev_get_queue(bdev);
|
|
|
|
start += get_start_sect(bdev);
|
|
|
|
return blk_stack_limits(t, &bq->limits, start);
|
|
}
|
|
EXPORT_SYMBOL(bdev_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 (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) {
|
|
char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE];
|
|
|
|
disk_name(disk, 0, top);
|
|
bdevname(bdev, bottom);
|
|
|
|
printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
|
|
top, bottom);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(disk_stack_limits);
|
|
|
|
/**
|
|
* blk_queue_dma_pad - set pad mask
|
|
* @q: the request queue for the device
|
|
* @mask: pad mask
|
|
*
|
|
* Set 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_dma_pad(struct request_queue *q, unsigned int mask)
|
|
{
|
|
q->dma_pad_mask = mask;
|
|
}
|
|
EXPORT_SYMBOL(blk_queue_dma_pad);
|
|
|
|
/**
|
|
* 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_dma_drain - Set up a drain buffer for excess dma.
|
|
* @q: the request queue for the device
|
|
* @dma_drain_needed: fn which returns non-zero if drain is necessary
|
|
* @buf: physically contiguous buffer
|
|
* @size: size of the buffer in bytes
|
|
*
|
|
* Some devices have excess DMA problems and can't simply discard (or
|
|
* zero fill) the unwanted piece of the transfer. They have to have a
|
|
* real area of memory to transfer it into. The use case for this is
|
|
* ATAPI devices in DMA mode. If the packet command causes a transfer
|
|
* bigger than the transfer size some HBAs will lock up if there
|
|
* aren't DMA elements to contain the excess transfer. What this API
|
|
* does is adjust the queue so that the buf is always appended
|
|
* silently to the scatterlist.
|
|
*
|
|
* Note: This routine adjusts max_hw_segments to make room for appending
|
|
* the drain buffer. If you call blk_queue_max_segments() after calling
|
|
* this routine, you must set the limit to one fewer than your device
|
|
* can support otherwise there won't be room for the drain buffer.
|
|
*/
|
|
int blk_queue_dma_drain(struct request_queue *q,
|
|
dma_drain_needed_fn *dma_drain_needed,
|
|
void *buf, unsigned int size)
|
|
{
|
|
if (queue_max_segments(q) < 2)
|
|
return -EINVAL;
|
|
/* make room for appending the drain */
|
|
blk_queue_max_segments(q, queue_max_segments(q) - 1);
|
|
q->dma_drain_needed = dma_drain_needed;
|
|
q->dma_drain_buffer = buf;
|
|
q->dma_drain_size = size;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_queue_dma_drain);
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
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->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->dma_alignment)
|
|
q->dma_alignment = mask;
|
|
}
|
|
EXPORT_SYMBOL(blk_queue_update_dma_alignment);
|
|
|
|
void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
|
|
{
|
|
spin_lock_irq(q->queue_lock);
|
|
if (queueable)
|
|
clear_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags);
|
|
else
|
|
set_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags);
|
|
spin_unlock_irq(q->queue_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
spin_lock_irq(q->queue_lock);
|
|
if (wc)
|
|
queue_flag_set(QUEUE_FLAG_WC, q);
|
|
else
|
|
queue_flag_clear(QUEUE_FLAG_WC, q);
|
|
if (fua)
|
|
queue_flag_set(QUEUE_FLAG_FUA, q);
|
|
else
|
|
queue_flag_clear(QUEUE_FLAG_FUA, q);
|
|
spin_unlock_irq(q->queue_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_queue_write_cache);
|
|
|
|
static int __init blk_settings_init(void)
|
|
{
|
|
blk_max_low_pfn = max_low_pfn - 1;
|
|
blk_max_pfn = max_pfn - 1;
|
|
return 0;
|
|
}
|
|
subsys_initcall(blk_settings_init);
|