[PATCH 5/8] io_uring/zcrx: convert io_zcrx_iov_page to use folios

[Pavel Begunkov <asml.silence@gmail.com>]

Modernise io_zcrx_iov_page() and make it return folios + offset. That
will be used for the next patches implementing area's page coalescing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/zcrx.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index a2493798e6f8..a83b80c16491 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -40,13 +40,17 @@ static inline struct io_zcrx_area *io_zcrx_iov_to_area(const struct net_iov *nio
 	return container_of(owner, struct io_zcrx_area, nia);
 }
 
-static inline struct page *io_zcrx_iov_page(const struct net_iov *niov)
+static inline struct folio *io_niov_folio(const struct net_iov *niov,
+					  unsigned long *off)
 {
 	struct io_zcrx_area *area = io_zcrx_iov_to_area(niov);
+	struct page *page;
 
 	lockdep_assert(!area->mem.is_dmabuf);
 
-	return area->mem.pages[net_iov_idx(niov)];
+	page = area->mem.pages[net_iov_idx(niov)];
+	*off = (page - compound_head(page)) << PAGE_SHIFT;
+	return page_folio(page);
 }
 
 static int io_populate_area_dma(struct io_zcrx_ifq *ifq,
@@ -944,7 +948,8 @@ static ssize_t io_zcrx_copy_chunk(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
 		size_t copy_size = min_t(size_t, PAGE_SIZE, len);
 		const int dst_off = 0;
 		struct net_iov *niov;
-		struct page *dst_page;
+		struct folio *dst_folio;
+		unsigned long dst_folio_off;
 		void *dst_addr;
 
 		niov = io_zcrx_alloc_fallback(area);
@@ -953,8 +958,8 @@ static ssize_t io_zcrx_copy_chunk(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
 			break;
 		}
 
-		dst_page = io_zcrx_iov_page(niov);
-		dst_addr = kmap_local_page(dst_page);
+		dst_folio = io_niov_folio(niov, &dst_folio_off);
+		dst_addr = kmap_local_folio(dst_folio, dst_folio_off);
 		if (src_page)
 			src_base = kmap_local_page(src_page);
 
-- 
2.49.0