On 25.01.23 22:06, David Howells wrote:
Define flags to qualify page extraction to pass into iov_iter_*_pages*()
rather than passing in FOLL_* flags.
For now only a flag to allow peer-to-peer DMA is supported.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
cc: linux-fsdevel@xxxxxxxxxxxxxxx
cc: linux-block@xxxxxxxxxxxxxxx
---
[...]
+++ b/include/linux/uio.h
@@ -252,12 +252,12 @@ void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *
loff_t start, size_t count);
ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
size_t maxsize, unsigned maxpages, size_t *start,
- unsigned gup_flags);
+ unsigned extraction_flags);
ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages,
size_t maxsize, unsigned maxpages, size_t *start);
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
struct page ***pages, size_t maxsize, size_t *start,
- unsigned gup_flags);
+ unsigned extraction_flags);
ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages,
size_t maxsize, size_t *start);
int iov_iter_npages(const struct iov_iter *i, int maxpages);
@@ -360,4 +360,7 @@ static inline void iov_iter_ubuf(struct iov_iter *i, unsigned int direction,
};
}
+/* Flags for iov_iter_get/extract_pages*() */
+#define ITER_ALLOW_P2PDMA 0x01 /* Allow P2PDMA on the extracted pages */
Just a note that the usage of new __bitwise types instead of "unsigned"
is encouraged for flags.
See rmap_t in include/linux/rmap.h as an example.
Apart from that LGTM.
--
Thanks,
David / dhildenb
