From 9223687863ffa63fa655f52ef64148ee08dee4d1 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Wed, 27 Nov 2013 16:29:46 -0800 Subject: iov_iter: Move iov_iter to uio.h Signed-off-by: Kent Overstreet --- include/linux/uio.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'include/linux/uio.h') diff --git a/include/linux/uio.h b/include/linux/uio.h index c55ce243cc09..347d70ce098e 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -9,14 +9,23 @@ #ifndef __LINUX_UIO_H #define __LINUX_UIO_H +#include #include +struct page; struct kvec { void *iov_base; /* and that should *never* hold a userland pointer */ size_t iov_len; }; +struct iov_iter { + const struct iovec *iov; + unsigned long nr_segs; + size_t iov_offset; + size_t count; +}; + /* * Total number of bytes covered by an iovec. * @@ -34,8 +43,49 @@ static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs) return ret; } +static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) +{ + return (struct iovec) { + .iov_base = iter->iov->iov_base + iter->iov_offset, + .iov_len = min(iter->count, + iter->iov->iov_len - iter->iov_offset), + }; +} + +#define iov_for_each(iov, iter, start) \ + for (iter = (start); \ + (iter).count && \ + ((iov = iov_iter_iovec(&(iter))), 1); \ + iov_iter_advance(&(iter), (iov).iov_len)) + unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); +size_t iov_iter_copy_from_user_atomic(struct page *page, + struct iov_iter *i, unsigned long offset, size_t bytes); +size_t iov_iter_copy_from_user(struct page *page, + struct iov_iter *i, unsigned long offset, size_t bytes); +void iov_iter_advance(struct iov_iter *i, size_t bytes); +int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes); +size_t iov_iter_single_seg_count(const struct iov_iter *i); + +static inline void iov_iter_init(struct iov_iter *i, + const struct iovec *iov, unsigned long nr_segs, + size_t count, size_t written) +{ + i->iov = iov; + i->nr_segs = nr_segs; + i->iov_offset = 0; + i->count = count + written; + + iov_iter_advance(i, written); +} + +static inline size_t iov_iter_count(struct iov_iter *i) +{ + return i->count; +} + int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len); int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len); + #endif -- cgit v1.2.3-59-g8ed1b