From 2b43470add8c8ff1e1ee28dffc5c5df97e955d09 Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Wed, 20 May 2020 21:20:53 +0200 Subject: xsk: Introduce AF_XDP buffer allocation API MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In order to simplify AF_XDP zero-copy enablement for NIC driver developers, a new AF_XDP buffer allocation API is added. The implementation is based on a single core (single producer/consumer) buffer pool for the AF_XDP UMEM. A buffer is allocated using the xsk_buff_alloc() function, and returned using xsk_buff_free(). If a buffer is disassociated with the pool, e.g. when a buffer is passed to an AF_XDP socket, a buffer is said to be released. Currently, the release function is only used by the AF_XDP internals and not visible to the driver. Drivers using this API should register the XDP memory model with the new MEM_TYPE_XSK_BUFF_POOL type. The API is defined in net/xdp_sock_drv.h. The buffer type is struct xdp_buff, and follows the lifetime of regular xdp_buffs, i.e. the lifetime of an xdp_buff is restricted to a NAPI context. In other words, the API is not replacing xdp_frames. In addition to introducing the API and implementations, the AF_XDP core is migrated to use the new APIs. rfc->v1: Fixed build errors/warnings for m68k and riscv. (kbuild test robot) Added headroom/chunk size getter. (Maxim/Björn) v1->v2: Swapped SoBs. (Maxim) v2->v3: Initialize struct xdp_buff member frame_sz. (Björn) Add API to query the DMA address of a frame. (Maxim) Do DMA sync for CPU till the end of the frame to handle possible growth (frame_sz). (Maxim) Signed-off-by: Björn Töpel Signed-off-by: Maxim Mikityanskiy Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200520192103.355233-6-bjorn.topel@gmail.com --- include/net/xdp_sock.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/net/xdp_sock.h') diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index fb7fe3060175..6e7265f63c04 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -31,11 +31,13 @@ struct xdp_umem_fq_reuse { struct xdp_umem { struct xsk_queue *fq; struct xsk_queue *cq; + struct xsk_buff_pool *pool; struct xdp_umem_page *pages; u64 chunk_mask; u64 size; u32 headroom; u32 chunk_size_nohr; + u32 chunk_size; struct user_struct *user; refcount_t users; struct work_struct work; -- cgit v1.2.3-59-g8ed1b