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-rw-r--r--include/linux/uio.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h
index c55ce24..199bcc3 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -9,14 +9,23 @@
#ifndef __LINUX_UIO_H
#define __LINUX_UIO_H
+#include <linux/kernel.h>
#include <uapi/linux/uio.h>
+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 +43,51 @@ 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);
+size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
+ 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
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