From 2b43470add8c8ff1e1ee28dffc5c5df97e955d09 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= 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_drv.h | 164 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+) (limited to 'include/net/xdp_sock_drv.h') diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h index d67f2361937a..7752c8663d1b 100644 --- a/include/net/xdp_sock_drv.h +++ b/include/net/xdp_sock_drv.h @@ -7,6 +7,7 @@ #define _LINUX_XDP_SOCK_DRV_H #include +#include #ifdef CONFIG_XDP_SOCKETS @@ -101,6 +102,94 @@ static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem) return umem->chunk_size_nohr; } +static inline u32 xsk_umem_get_headroom(struct xdp_umem *umem) +{ + return XDP_PACKET_HEADROOM + umem->headroom; +} + +static inline u32 xsk_umem_get_chunk_size(struct xdp_umem *umem) +{ + return umem->chunk_size; +} + +static inline u32 xsk_umem_get_rx_frame_size(struct xdp_umem *umem) +{ + return xsk_umem_get_chunk_size(umem) - xsk_umem_get_headroom(umem); +} + +static inline void xsk_buff_set_rxq_info(struct xdp_umem *umem, + struct xdp_rxq_info *rxq) +{ + xp_set_rxq_info(umem->pool, rxq); +} + +static inline void xsk_buff_dma_unmap(struct xdp_umem *umem, + unsigned long attrs) +{ + xp_dma_unmap(umem->pool, attrs); +} + +static inline int xsk_buff_dma_map(struct xdp_umem *umem, struct device *dev, + unsigned long attrs) +{ + return xp_dma_map(umem->pool, dev, attrs, umem->pgs, umem->npgs); +} + +static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp) +{ + struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); + + return xp_get_dma(xskb); +} + +static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp) +{ + struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); + + return xp_get_frame_dma(xskb); +} + +static inline struct xdp_buff *xsk_buff_alloc(struct xdp_umem *umem) +{ + return xp_alloc(umem->pool); +} + +static inline bool xsk_buff_can_alloc(struct xdp_umem *umem, u32 count) +{ + return xp_can_alloc(umem->pool, count); +} + +static inline void xsk_buff_free(struct xdp_buff *xdp) +{ + struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); + + xp_free(xskb); +} + +static inline dma_addr_t xsk_buff_raw_get_dma(struct xdp_umem *umem, u64 addr) +{ + return xp_raw_get_dma(umem->pool, addr); +} + +static inline void *xsk_buff_raw_get_data(struct xdp_umem *umem, u64 addr) +{ + return xp_raw_get_data(umem->pool, addr); +} + +static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp) +{ + struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); + + xp_dma_sync_for_cpu(xskb); +} + +static inline void xsk_buff_raw_dma_sync_for_device(struct xdp_umem *umem, + dma_addr_t dma, + size_t size) +{ + xp_dma_sync_for_device(umem->pool, dma, size); +} + #else static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt) @@ -212,6 +301,81 @@ static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem) return 0; } +static inline u32 xsk_umem_get_headroom(struct xdp_umem *umem) +{ + return 0; +} + +static inline u32 xsk_umem_get_chunk_size(struct xdp_umem *umem) +{ + return 0; +} + +static inline u32 xsk_umem_get_rx_frame_size(struct xdp_umem *umem) +{ + return 0; +} + +static inline void xsk_buff_set_rxq_info(struct xdp_umem *umem, + struct xdp_rxq_info *rxq) +{ +} + +static inline void xsk_buff_dma_unmap(struct xdp_umem *umem, + unsigned long attrs) +{ +} + +static inline int xsk_buff_dma_map(struct xdp_umem *umem, struct device *dev, + unsigned long attrs) +{ + return 0; +} + +static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp) +{ + return 0; +} + +static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp) +{ + return 0; +} + +static inline struct xdp_buff *xsk_buff_alloc(struct xdp_umem *umem) +{ + return NULL; +} + +static inline bool xsk_buff_can_alloc(struct xdp_umem *umem, u32 count) +{ + return false; +} + +static inline void xsk_buff_free(struct xdp_buff *xdp) +{ +} + +static inline dma_addr_t xsk_buff_raw_get_dma(struct xdp_umem *umem, u64 addr) +{ + return 0; +} + +static inline void *xsk_buff_raw_get_data(struct xdp_umem *umem, u64 addr) +{ + return NULL; +} + +static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp) +{ +} + +static inline void xsk_buff_raw_dma_sync_for_device(struct xdp_umem *umem, + dma_addr_t dma, + size_t size) +{ +} + #endif /* CONFIG_XDP_SOCKETS */ #endif /* _LINUX_XDP_SOCK_DRV_H */ -- cgit v1.2.3