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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#include <linux/highmem.h>#include <linux/bug.h>#include <linux/errno.h>#include <linux/limits.h>#include <linux/minmax.h>#include <linux/types.h>
struct page;
/** * struct bio_vec - a contiguous range of physical memory addresses * @bv_page: First page associated with the address range. * @bv_len: Number of bytes in the address range. * @bv_offset: Start of the address range relative to the start of @bv_page. * * All pages within a bio_vec starting from @bv_page are contiguous and * can simply be iterated (see bvec_advance()). */struct bio_vec { struct page *bv_page; unsigned int bv_len; unsigned int bv_offset;};
/** * bvec_set_page - initialize a bvec based off a struct page * @bv: bvec to initialize * @page: page the bvec should point to * @len: length of the bvec * @offset: offset into the page */static inline void bvec_set_page(struct bio_vec *bv, struct page *page, unsigned int len, unsigned int offset){ bv->bv_page = page; bv->bv_len = len; bv->bv_offset = offset;}
/** * bvec_set_folio - initialize a bvec based off a struct folio * @bv: bvec to initialize * @folio: folio the bvec should point to * @len: length of the bvec * @offset: offset into the folio */static inline void bvec_set_folio(struct bio_vec *bv, struct folio *folio, size_t len, size_t offset){ unsigned long nr = offset / PAGE_SIZE;
WARN_ON_ONCE(len > UINT_MAX); bvec_set_page(bv, folio_page(folio, nr), len, offset % PAGE_SIZE);}
/** * bvec_set_virt - initialize a bvec based on a virtual address * @bv: bvec to initialize * @vaddr: virtual address to set the bvec to * @len: length of the bvec */static inline void bvec_set_virt(struct bio_vec *bv, void *vaddr, unsigned int len){ bvec_set_page(bv, virt_to_page(vaddr), len, offset_in_page(vaddr));}
/** * bvec_folio - Return the first folio referenced by this bvec * @bv: bvec to access * * A bvec can contain non-folio memory, so this should only be called by * the creator of the bvec; drivers have no business looking at the owner * of the memory. It may not even be the right interface for the caller * to use as a bvec can span multiple folios. You may be better off using * something like bio_for_each_folio_all() which iterates over all folios. */static inline struct folio *bvec_folio(const struct bio_vec *bv){ return page_folio(bv->bv_page);}
struct bvec_iter { /* * Current device address in 512 byte sectors. Only updated by the bio * iter wrappers and not the bvec iterator helpers themselves. */ sector_t bi_sector;
/* * Remaining size in bytes. */ unsigned int bi_size;
/* * Current index into the bvec array. This indexes into `bi_io_vec` when * iterating a bvec array that is part of a `bio`. */ unsigned int bi_idx;
/* * Current offset in the bvec entry pointed to by `bi_idx` or into * a dma-buf map. */ unsigned int bi_offset;} __packed __aligned(4);
struct bvec_iter_all { struct bio_vec bv; int idx; unsigned done;};
static __always_inline const struct bio_vec *__bvec_iter_bvec(const struct bio_vec *bvecs, const struct bvec_iter iter){ return bvecs + iter.bi_idx;}
/* multi-page (mp_bvec) helpers */static __always_inline struct page *mp_bvec_iter_page(const struct bio_vec *bvecs, const struct bvec_iter iter){ return __bvec_iter_bvec(bvecs, iter)->bv_page;}
static __always_inline unsigned intmp_bvec_iter_len(const struct bio_vec *bvecs, const struct bvec_iter iter){ return min(__bvec_iter_bvec(bvecs, iter)->bv_len - iter.bi_offset, iter.bi_size);}
static __always_inline unsigned intmp_bvec_iter_offset(const struct bio_vec *bvecs, const struct bvec_iter iter){ return __bvec_iter_bvec(bvecs, iter)->bv_offset + iter.bi_offset;}
static __always_inline unsigned intmp_bvec_iter_page_idx(const struct bio_vec *bvecs, const struct bvec_iter iter){ return mp_bvec_iter_offset(bvecs, iter) / PAGE_SIZE;}
static __always_inline struct bio_vecmp_bvec_iter_bvec(const struct bio_vec *bvecs, const struct bvec_iter iter){ return (struct bio_vec) { .bv_page = mp_bvec_iter_page(bvecs, iter), .bv_len = mp_bvec_iter_len(bvecs, iter), .bv_offset = mp_bvec_iter_offset(bvecs, iter), };}
/* For building single-page bvec in flight */static __always_inline unsigned intbvec_iter_offset(const struct bio_vec *bvecs, const struct bvec_iter iter){ return mp_bvec_iter_offset(bvecs, iter) % PAGE_SIZE;}
static __always_inline unsigned intbvec_iter_len(const struct bio_vec *bvecs, const struct bvec_iter iter){ return min(mp_bvec_iter_len(bvecs, iter), PAGE_SIZE - bvec_iter_offset(bvecs, iter));}
static __always_inline struct page *bvec_iter_page(const struct bio_vec *bvecs, const struct bvec_iter iter){ return mp_bvec_iter_page(bvecs, iter) + mp_bvec_iter_page_idx(bvecs, iter);}
static __always_inline struct bio_vecbvec_iter_bvec(const struct bio_vec *bvecs, const struct bvec_iter iter){ return (struct bio_vec) { .bv_page = bvec_iter_page(bvecs, iter), .bv_len = bvec_iter_len(bvecs, iter), .bv_offset = bvec_iter_offset(bvecs, iter), };}
static inline bool bvec_iter_advance(const struct bio_vec *bv, struct bvec_iter *iter, unsigned bytes){ unsigned int idx = iter->bi_idx;
if (WARN_ONCE(bytes > iter->bi_size, "Attempted to advance past end of bvec iter\n")) { iter->bi_size = 0; return false; }
iter->bi_size -= bytes; bytes += iter->bi_offset;
while (bytes && bytes >= bv[idx].bv_len) { bytes -= bv[idx].bv_len; idx++; }
iter->bi_idx = idx; iter->bi_offset = bytes; return true;}
/* * A simpler version of bvec_iter_advance(), @bytes should not span * across multiple bvec entries, i.e. bytes <= bv[i->bi_idx].bv_len */static inline void bvec_iter_advance_single(const struct bio_vec *bv, struct bvec_iter *iter, unsigned int bytes){ unsigned int done = iter->bi_offset + bytes;
if (done == bv[iter->bi_idx].bv_len) { done = 0; iter->bi_idx++; } iter->bi_offset = done; iter->bi_size -= bytes;}
#define for_each_bvec(bvl, bio_vec, iter, start) \ for (iter = (start); \ (iter).bi_size && \ ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \ bvec_iter_advance_single((bio_vec), &(iter), (bvl).bv_len))
#define for_each_mp_bvec(bvl, bio_vec, iter, start) \ for (iter = (start); \ (iter).bi_size && \ ((bvl = mp_bvec_iter_bvec((bio_vec), (iter))), 1); \ bvec_iter_advance_single((bio_vec), &(iter), (bvl).bv_len))
static inline struct bio_vec *bvec_init_iter_all(struct bvec_iter_all *iter_all){ iter_all->done = 0; iter_all->idx = 0;
return &iter_all->bv;}
static inline void bvec_advance(const struct bio_vec *bvec, struct bvec_iter_all *iter_all){ struct bio_vec *bv = &iter_all->bv;
if (iter_all->done) { bv->bv_page++; bv->bv_offset = 0; } else { bv->bv_page = bvec->bv_page + (bvec->bv_offset >> PAGE_SHIFT); bv->bv_offset = bvec->bv_offset & ~PAGE_MASK; } bv->bv_len = min_t(unsigned int, PAGE_SIZE - bv->bv_offset, bvec->bv_len - iter_all->done); iter_all->done += bv->bv_len;
if (iter_all->done == bvec->bv_len) { iter_all->idx++; iter_all->done = 0; }}
/** * bvec_kmap_local - map a bvec into the kernel virtual address space * @bvec: bvec to map * * Must be called on single-page bvecs only. Call kunmap_local on the returned * address to unmap. */static inline void *bvec_kmap_local(struct bio_vec *bvec){ return kmap_local_page(bvec->bv_page) + bvec->bv_offset;}
/** * memcpy_from_bvec - copy data from a bvec * @to: Kernel virtual address to copy to. * @bvec: bvec to copy from * * Must be called on single-page bvecs only. */static inline void memcpy_from_bvec(char *to, struct bio_vec *bvec){ memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, bvec->bv_len);}
/** * memcpy_to_bvec - copy data to a bvec * @bvec: bvec to copy to * @from: Kernel virtual address to copy from. * * Must be called on single-page bvecs only. */static inline void memcpy_to_bvec(struct bio_vec *bvec, const char *from){ memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, bvec->bv_len);}
/** * memzero_bvec - zero all data in a bvec * @bvec: bvec to zero * * Must be called on single-page bvecs only. */static inline void memzero_bvec(struct bio_vec *bvec){ memzero_page(bvec->bv_page, bvec->bv_offset, bvec->bv_len);}
/** * bvec_virt - return the virtual address for a bvec * @bvec: bvec to return the virtual address for * * Note: the caller must ensure that @bvec->bv_page is not a highmem page. */static inline void *bvec_virt(struct bio_vec *bvec){ WARN_ON_ONCE(PageHighMem(bvec->bv_page)); return page_address(bvec->bv_page) + bvec->bv_offset;}
/** * bvec_phys - return the physical address for a bvec * @bvec: bvec to return the physical address for */static inline phys_addr_t bvec_phys(const struct bio_vec *bvec){ return page_to_phys(bvec->bv_page) + bvec->bv_offset;}
#endif /* __LINUX_BVEC_H */