linux/include/linux/bvec.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * bvec iterator
 *
 * Copyright (C) 2001 Ming Lei <[email protected]>
 */
#ifndef __LINUX_BVEC_H
#define __LINUX_BVEC_H

#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.
 *
 * The following holds for a bvec if n * PAGE_SIZE < bv_offset + bv_len:
 *
 *   nth_page(@bv_page, n) == @bv_page + n
 *
 * This holds because page_is_mergeable() checks the above property.
 */
struct bio_vec { … };

/**
 * 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)
{ … }

/**
 * 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,
		unsigned int len, unsigned int offset)
{ … }

/**
 * 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)
{ … }

struct bvec_iter { … } __packed __aligned(…);

struct bvec_iter_all { … };

/*
 * various member access, note that bio_data should of course not be used
 * on highmem page vectors
 */
#define __bvec_iter_bvec(bvec, iter) …

/* multi-page (mp_bvec) helpers */
#define mp_bvec_iter_page(bvec, iter) …

#define mp_bvec_iter_len(bvec, iter) …

#define mp_bvec_iter_offset(bvec, iter) …

#define mp_bvec_iter_page_idx(bvec, iter) …

#define mp_bvec_iter_bvec(bvec, iter) …

/* For building single-page bvec in flight */
 #define bvec_iter_offset(bvec, iter) …

#define bvec_iter_len(bvec, iter) …

#define bvec_iter_page(bvec, iter) …

#define bvec_iter_bvec(bvec, iter) …

static inline bool bvec_iter_advance(const struct bio_vec *bv,
		struct bvec_iter *iter, unsigned bytes)
{ … }

/*
 * 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)
{ … }

#define for_each_bvec(bvl, bio_vec, iter, start) …

/* for iterating one bio from start to end */
#define BVEC_ITER_ALL_INIT …

static inline struct bio_vec *bvec_init_iter_all(struct bvec_iter_all *iter_all)
{ … }

static inline void bvec_advance(const struct bio_vec *bvec,
				struct bvec_iter_all *iter_all)
{ … }

/**
 * 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)
{ … }

/**
 * memcpy_from_bvec - copy data from a bvec
 * @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_to_bvec - copy data to a bvec
 * @bvec: bvec to copy to
 *
 * Must be called on single-page bvecs only.
 */
static inline void memcpy_to_bvec(struct bio_vec *bvec, const char *from)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

#endif /* __LINUX_BVEC_H */