Document enum iter_type, copy_to_iter() and copy_from_iter()
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/uio.h | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 6350354f97e9..9fbce8c92545 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -17,6 +17,15 @@ struct kvec {
size_t iov_len;
};
+/**
+ * enum iter_type - The type of memory referred to by the iterator.
+ * @ITER_IOVEC: An array of ranges of userspace memory.
+ * @ITER_KVEC: An array of ranges of kernel memory.
+ * @ITER_BVEC: An array of &struct bio_vec.
+ * @ITER_PIPE: A pipe.
+ * @ITER_XARRAY: A &struct xarray of pages.
+ * @ITER_DISCARD: No memory here; discard all writes.
+ */
enum iter_type {
/* iter types */
ITER_IOVEC,
@@ -146,6 +155,18 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
+/**
+ * copy_to_iter() - Copy from kernel memory to an iterator.
+ * @addr: Kernel memory address.
+ * @bytes: Number of bytes to copy.
+ * @i: Destination of copy.
+ *
+ * Copy @bytes from @addr to @i. The region of memory pointed to by @i must
+ * not overlap the region pointed to by @addr. @i may point to any kind
+ * of &enum iter_type memory.
+ *
+ * Return: Number of bytes successfully copied to the iterator.
+ */
static __always_inline __must_check
size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
@@ -155,6 +176,18 @@ size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
return _copy_to_iter(addr, bytes, i);
}
+/**
+ * copy_from_iter() - Copy from an iterator to kernel memory.
+ * @addr: Kernel memory address.
+ * @bytes: Number of bytes to copy.
+ * @i: Source of memory.
+ *
+ * Copy @bytes from @i to @addr. The region of memory pointed to by @i must
+ * not overlap the region pointed to by @addr. @i may point to any kind
+ * of &enum iter_type memory.
+ *
+ * Return: Number of bytes successfully copied from the iterator.
+ */
static __always_inline __must_check
size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
--
2.33.0
