1c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 2c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 2.5 block I/O model 3c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 4c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Copyright (C) 2001 Jens Axboe <axboe@suse.de> 5c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 6c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This program is free software; you can redistribute it and/or modify 7c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * it under the terms of the GNU General Public License version 2 as 8c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * published by the Free Software Foundation. 9c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 10c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This program is distributed in the hope that it will be useful, 11c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * but WITHOUT ANY WARRANTY; without even the implied warranty of 12c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 13c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * GNU General Public License for more details. 15c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 16c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * You should have received a copy of the GNU General Public Licens 17c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * along with this program; if not, write to the Free Software 18c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- 19c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 20c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifndef __LINUX_BIO_H 21c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __LINUX_BIO_H 22c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 23c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/highmem.h> 24c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/mempool.h> 25c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/ioprio.h> 26c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 27c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* Platforms may set this to teach the BIO layer about IOMMU hardware. */ 28c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <asm/io.h> 29c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 30c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#if defined(BIO_VMERGE_MAX_SIZE) && defined(BIO_VMERGE_BOUNDARY) 31c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIOVEC_VIRT_START_SIZE(x) (bvec_to_phys(x) & (BIO_VMERGE_BOUNDARY - 1)) 32c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIOVEC_VIRT_OVERSIZE(x) ((x) > BIO_VMERGE_MAX_SIZE) 33c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#else 34c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIOVEC_VIRT_START_SIZE(x) 0 35c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIOVEC_VIRT_OVERSIZE(x) 0 36c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 37c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 38c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifndef BIO_VMERGE_BOUNDARY 39c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_VMERGE_BOUNDARY 0 40c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 41c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 42c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_DEBUG 43c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 44c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifdef BIO_DEBUG 45c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_BUG_ON BUG_ON 46c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#else 47c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_BUG_ON 48c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 49c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 50c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_MAX_PAGES 256 51c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT) 52c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9) 53c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 54c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 55c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * was unsigned short, but we might as well be ready for > 64kB I/O pages 56c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 57c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct bio_vec { 58c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct page *bv_page; 59c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned int bv_len; 60c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned int bv_offset; 61c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}; 62c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 63c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct bio_set; 64c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct bio; 65c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querutypedef int (bio_end_io_t) (struct bio *, unsigned int, int); 66c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querutypedef void (bio_destructor_t) (struct bio *); 67c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 68c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 69c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * main unit of I/O for the block layer and lower layers (ie drivers and 70c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * stacking drivers) 71c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 72c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct bio { 73c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru sector_t bi_sector; 74c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct bio *bi_next; /* request queue link */ 75c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct block_device *bi_bdev; 76c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long bi_flags; /* status, command, etc */ 77c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long bi_rw; /* bottom bits READ/WRITE, 78c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * top bits priority 79c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 80c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 81c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned short bi_vcnt; /* how many bio_vec's */ 82c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned short bi_idx; /* current index into bvl_vec */ 83c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 84c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* Number of segments in this BIO after 85c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * physical address coalescing is performed. 86c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 87c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned short bi_phys_segments; 88c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 89c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* Number of segments after physical and DMA remapping 90c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * hardware coalescing is performed. 91c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 92c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned short bi_hw_segments; 93c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 94c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned int bi_size; /* residual I/O count */ 95c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 96c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* 97c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * To keep track of the max hw size, we account for the 98c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * sizes of the first and last virtually mergeable segments 99c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * in this bio 100c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 101c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned int bi_hw_front_size; 102c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned int bi_hw_back_size; 103c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 104c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ 105c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 106c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct bio_vec *bi_io_vec; /* the actual vec list */ 107c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 108c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru bio_end_io_t *bi_end_io; 109c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru atomic_t bi_cnt; /* pin count */ 110c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 111c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru void *bi_private; 112c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 113c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru bio_destructor_t *bi_destructor; /* destructor */ 114c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}; 115c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 116c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 117c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bio flags 118c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 119c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_UPTODATE 0 /* ok after I/O completion */ 120c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */ 121c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_EOF 2 /* out-out-bounds error */ 122c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_SEG_VALID 3 /* nr_hw_seg valid */ 123c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_CLONED 4 /* doesn't own data */ 124c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_BOUNCED 5 /* bio is a bounce bio */ 125c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_USER_MAPPED 6 /* contains user pages */ 126c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_EOPNOTSUPP 7 /* not supported */ 127c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) 128c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 129c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 130c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * top 4 bits of bio flags indicate the pool this bio came from 131c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 132c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_POOL_BITS (4) 133c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS) 134c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET) 135c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET) 136c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 137c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 138c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bio bi_rw flags 139c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 140c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bit 0 -- read (not set) or write (set) 141c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bit 1 -- rw-ahead when set 142c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bit 2 -- barrier 143c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bit 3 -- fail fast, don't want low level driver retries 144c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bit 4 -- synchronous I/O hint: the block layer will unplug immediately 145c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 146c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_RW 0 147c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_RW_AHEAD 1 148c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_RW_BARRIER 2 149c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_RW_FAILFAST 3 150c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_RW_SYNC 4 151c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 152c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 153c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * upper 16 bits of bi_rw define the io priority of this bio 154c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 155c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS) 156c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT) 157c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio)) 158c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 159c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_set_prio(bio, prio) do { \ 160c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru WARN_ON(prio >= (1 << IOPRIO_BITS)); \ 161c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \ 162c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \ 163c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} while (0) 164c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 165c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 166c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * various member access, note that bio_data should of course not be used 167c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * on highmem page vectors 168c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 169c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)])) 170c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx) 171c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_page(bio) bio_iovec((bio))->bv_page 172c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_offset(bio) bio_iovec((bio))->bv_offset 173c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx) 174c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_sectors(bio) ((bio)->bi_size >> 9) 175c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_cur_sectors(bio) (bio_iovec(bio)->bv_len >> 9) 176c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_data(bio) (page_address(bio_page((bio))) + bio_offset((bio))) 177c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER)) 178c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC)) 179c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_failfast(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST)) 180c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD)) 181c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 182c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 183c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * will die 184c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 185c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio))) 186c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset) 187c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 188c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 189c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * queues that have highmem support enabled may still need to revert to 190c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * PIO transfers occasionally and thus map high pages temporarily. For 191c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * permanent PIO fall back, user is probably better off disabling highmem 192c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * I/O completely on that queue (see ide-dma for example) 193c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 194c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __bio_kmap_atomic(bio, idx, kmtype) \ 195c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \ 196c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru bio_iovec_idx((bio), (idx))->bv_offset) 197c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 198c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype) 199c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 200c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 201c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * merge helpers etc 202c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 203c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 204c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1) 205c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx) 206c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 207c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 208c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * allow arch override, for eg virtualized architectures (put in asm/io.h) 209c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 210c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifndef BIOVEC_PHYS_MERGEABLE 211c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \ 212c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2))) 213c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 214c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 215c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIOVEC_VIRT_MERGEABLE(vec1, vec2) \ 216c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru ((((bvec_to_phys((vec1)) + (vec1)->bv_len) | bvec_to_phys((vec2))) & (BIO_VMERGE_BOUNDARY - 1)) == 0) 217c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \ 218c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (((addr1) | (mask)) == (((addr2) - 1) | (mask))) 219c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \ 220c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask) 221c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define BIO_SEG_BOUNDARY(q, b1, b2) \ 222c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2))) 223c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 224c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_io_error(bio, bytes) bio_endio((bio), (bytes), -EIO) 225c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 226c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 227c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * drivers should not use the __ version unless they _really_ want to 228c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * run through the entire bio and not just pending pieces 229c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 230c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __bio_for_each_segment(bvl, bio, i, start_idx) \ 231c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \ 232c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru i < (bio)->bi_vcnt; \ 233c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru bvl++, i++) 234c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 235c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_for_each_segment(bvl, bio, i) \ 236c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx) 237c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 238c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 239c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * get a reference to a bio, so it won't disappear. the intended use is 240c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * something like: 241c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 242c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bio_get(bio); 243c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * submit_bio(rw, bio); 244c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * if (bio->bi_flags ...) 245c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * do_something 246c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bio_put(bio); 247c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 248c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * without the bio_get(), it could potentially complete I/O before submit_bio 249c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * returns. and then bio would be freed memory when if (bio->bi_flags ...) 250c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * runs 251c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 252c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_get(bio) atomic_inc(&(bio)->bi_cnt) 253c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 254c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 255c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 256c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * A bio_pair is used when we need to split a bio. 257c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This can only happen for a bio that refers to just one 258c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * page of data, and in the unusual situation when the 259c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * page crosses a chunk/device boundary 260c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 261c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * The address of the master bio is stored in bio1.bi_private 262c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * The address of the pool the pair was allocated from is stored 263c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * in bio2.bi_private 264c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 265c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct bio_pair { 266c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct bio bio1, bio2; 267c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct bio_vec bv1, bv2; 268c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru atomic_t cnt; 269c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int error; 270c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}; 271c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, 272c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int first_sectors); 273c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern mempool_t *bio_split_pool; 274c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_pair_release(struct bio_pair *dbio); 275c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 276c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio_set *bioset_create(int, int, int); 277c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bioset_free(struct bio_set *); 278c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 279c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio *bio_alloc(gfp_t, int); 280c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *); 281c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_put(struct bio *); 282c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_free(struct bio *, struct bio_set *); 283c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 284c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_endio(struct bio *, unsigned int, int); 285c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct request_queue; 286c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int bio_phys_segments(struct request_queue *, struct bio *); 287c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int bio_hw_segments(struct request_queue *, struct bio *); 288c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 289c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __bio_clone(struct bio *, struct bio *); 290c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio *bio_clone(struct bio *, gfp_t); 291c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 292c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_init(struct bio *); 293c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 294c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 295c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, 296c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned int, unsigned int); 297c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int bio_get_nr_vecs(struct block_device *); 298c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio *bio_map_user(struct request_queue *, struct block_device *, 299c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long, unsigned int, int); 300c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct sg_iovec; 301c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio *bio_map_user_iov(struct request_queue *, 302c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct block_device *, 303c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct sg_iovec *, int, int); 304c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_unmap_user(struct bio *); 305c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, 306c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru gfp_t); 307c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_set_pages_dirty(struct bio *bio); 308c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void bio_check_pages_dirty(struct bio *bio); 309c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct bio *bio_copy_user(struct request_queue *, unsigned long, unsigned int, int); 310c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int bio_uncopy_user(struct bio *); 311c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruvoid zero_fill_bio(struct bio *bio); 312c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 313c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifdef CONFIG_HIGHMEM 314c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 315c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * remember to add offset! and never ever reenable interrupts between a 316c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * bvec_kmap_irq and bvec_kunmap_irq!! 317c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * 318c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This function MUST be inlined - it plays with the CPU interrupt flags. 319c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 320c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags) 321c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{ 322c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long addr; 323c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 324c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* 325c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * might not be a highmem page, but the preempt/irq count 326c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * balancing is a lot nicer this way 327c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 328c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru local_irq_save(*flags); 329c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ); 330c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 331c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru BUG_ON(addr & ~PAGE_MASK); 332c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 333c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru return (char *) addr + bvec->bv_offset; 334c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} 335c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 336c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic inline void bvec_kunmap_irq(char *buffer, unsigned long *flags) 337c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{ 338c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long ptr = (unsigned long) buffer & PAGE_MASK; 339c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 340c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ); 341c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru local_irq_restore(*flags); 342c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} 343c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 344c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#else 345c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset) 346c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0) 347c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 348c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 349c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx, 350c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru unsigned long *flags) 351c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{ 352c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags); 353c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} 354c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags) 355c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 356c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_kmap_irq(bio, flags) \ 357c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru __bio_kmap_irq((bio), (bio)->bi_idx, (flags)) 358c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags) 359c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 360c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif /* __LINUX_BIO_H */ 361