From 54e89a93ef05d1a7c9996ff12e42eeecb4f66697 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Wed, 2 Jul 2025 15:29:06 +0100 Subject: [PATCH] io_uring/zcrx: introduce io_populate_area_dma Add a helper that initialises page-pool dma addresses from a sg table. It'll be reused in following patches. Signed-off-by: Pavel Begunkov Reviewed-by: David Wei Link: https://lore.kernel.org/r/a8972a77be9b5675abc585d6e2e6e30f9c7dbd85.1751466461.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/zcrx.c | 56 +++++++++++++++++++++++++++---------------------- 1 file changed, 31 insertions(+), 25 deletions(-) diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index 6fb7c9bedfcb1..172eb67ddc625 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -47,6 +47,35 @@ static inline struct page *io_zcrx_iov_page(const struct net_iov *niov) return area->mem.pages[net_iov_idx(niov)]; } +static int io_populate_area_dma(struct io_zcrx_ifq *ifq, + struct io_zcrx_area *area, + struct sg_table *sgt, unsigned long off) +{ + struct scatterlist *sg; + unsigned i, niov_idx = 0; + + for_each_sgtable_dma_sg(sgt, sg, i) { + dma_addr_t dma = sg_dma_address(sg); + unsigned long sg_len = sg_dma_len(sg); + unsigned long sg_off = min(sg_len, off); + + off -= sg_off; + sg_len -= sg_off; + dma += sg_off; + + while (sg_len && niov_idx < area->nia.num_niovs) { + struct net_iov *niov = &area->nia.niovs[niov_idx]; + + if (net_mp_niov_set_dma_addr(niov, dma)) + return -EFAULT; + sg_len -= PAGE_SIZE; + dma += PAGE_SIZE; + niov_idx++; + } + } + return 0; +} + static void io_release_dmabuf(struct io_zcrx_mem *mem) { if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) @@ -121,33 +150,10 @@ err: static int io_zcrx_map_area_dmabuf(struct io_zcrx_ifq *ifq, struct io_zcrx_area *area) { - unsigned long off = area->mem.dmabuf_offset; - struct scatterlist *sg; - unsigned i, niov_idx = 0; - if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) return -EINVAL; - - for_each_sgtable_dma_sg(area->mem.sgt, sg, i) { - dma_addr_t dma = sg_dma_address(sg); - unsigned long sg_len = sg_dma_len(sg); - unsigned long sg_off = min(sg_len, off); - - off -= sg_off; - sg_len -= sg_off; - dma += sg_off; - - while (sg_len && niov_idx < area->nia.num_niovs) { - struct net_iov *niov = &area->nia.niovs[niov_idx]; - - if (net_mp_niov_set_dma_addr(niov, dma)) - return -EFAULT; - sg_len -= PAGE_SIZE; - dma += PAGE_SIZE; - niov_idx++; - } - } - return 0; + return io_populate_area_dma(ifq, area, area->mem.sgt, + area->mem.dmabuf_offset); } static int io_import_umem(struct io_zcrx_ifq *ifq, -- 2.47.2