/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ /* * AF_XDP user-space access library. * * Copyright (c) 2018 - 2019 Intel Corporation. * Copyright (c) 2019 Facebook * * Author(s): Magnus Karlsson */ #ifndef __XSK_H #define __XSK_H #include #include #include #include #include #ifdef __cplusplus extern "C" { #endif /* Do not access these members directly. Use the functions below. */ #define DEFINE_XSK_RING(name) \ struct name { \ __u32 cached_prod; \ __u32 cached_cons; \ __u32 mask; \ __u32 size; \ __u32 *producer; \ __u32 *consumer; \ void *ring; \ __u32 *flags; \ } DEFINE_XSK_RING(xsk_ring_prod); DEFINE_XSK_RING(xsk_ring_cons); /* For a detailed explanation on the memory barriers associated with the * ring, please take a look at net/xdp/xsk_queue.h. */ struct xsk_umem; struct xsk_socket; static inline __u64 *xsk_ring_prod__fill_addr(struct xsk_ring_prod *fill, __u32 idx) { __u64 *addrs = (__u64 *)fill->ring; return &addrs[idx & fill->mask]; } static inline const __u64 * xsk_ring_cons__comp_addr(const struct xsk_ring_cons *comp, __u32 idx) { const __u64 *addrs = (const __u64 *)comp->ring; return &addrs[idx & comp->mask]; } static inline struct xdp_desc *xsk_ring_prod__tx_desc(struct xsk_ring_prod *tx, __u32 idx) { struct xdp_desc *descs = (struct xdp_desc *)tx->ring; return &descs[idx & tx->mask]; } static inline const struct xdp_desc * xsk_ring_cons__rx_desc(const struct xsk_ring_cons *rx, __u32 idx) { const struct xdp_desc *descs = (const struct xdp_desc *)rx->ring; return &descs[idx & rx->mask]; } static inline int xsk_ring_prod__needs_wakeup(const struct xsk_ring_prod *r) { return *r->flags & XDP_RING_NEED_WAKEUP; } static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb) { __u32 free_entries = r->cached_cons - r->cached_prod; if (free_entries >= nb) return free_entries; /* Refresh the local tail pointer. * cached_cons is r->size bigger than the real consumer pointer so * that this addition can be avoided in the more frequently * executed code that computs free_entries in the beginning of * this function. Without this optimization it whould have been * free_entries = r->cached_prod - r->cached_cons + r->size. */ r->cached_cons = __atomic_load_n(r->consumer, __ATOMIC_ACQUIRE); r->cached_cons += r->size; return r->cached_cons - r->cached_prod; } static inline __u32 xsk_cons_nb_avail(struct xsk_ring_cons *r, __u32 nb) { __u32 entries = r->cached_prod - r->cached_cons; if (entries == 0) { r->cached_prod = __atomic_load_n(r->producer, __ATOMIC_ACQUIRE); entries = r->cached_prod - r->cached_cons; } return (entries > nb) ? nb : entries; } static inline __u32 xsk_ring_prod__reserve(struct xsk_ring_prod *prod, __u32 nb, __u32 *idx) { if (xsk_prod_nb_free(prod, nb) < nb) return 0; *idx = prod->cached_prod; prod->cached_prod += nb; return nb; } static inline void xsk_ring_prod__submit(struct xsk_ring_prod *prod, __u32 nb) { /* Make sure everything has been written to the ring before indicating * this to the kernel by writing the producer pointer. */ __atomic_store_n(prod->producer, *prod->producer + nb, __ATOMIC_RELEASE); } static inline void xsk_ring_prod__cancel(struct xsk_ring_prod *prod, __u32 nb) { prod->cached_prod -= nb; } static inline __u32 xsk_ring_cons__peek(struct xsk_ring_cons *cons, __u32 nb, __u32 *idx) { __u32 entries = xsk_cons_nb_avail(cons, nb); if (entries > 0) { *idx = cons->cached_cons; cons->cached_cons += entries; } return entries; } static inline void xsk_ring_cons__cancel(struct xsk_ring_cons *cons, __u32 nb) { cons->cached_cons -= nb; } static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, __u32 nb) { /* Make sure data has been read before indicating we are done * with the entries by updating the consumer pointer. */ __atomic_store_n(cons->consumer, *cons->consumer + nb, __ATOMIC_RELEASE); } static inline void *xsk_umem__get_data(void *umem_area, __u64 addr) { return &((char *)umem_area)[addr]; } static inline __u64 xsk_umem__extract_addr(__u64 addr) { return addr & XSK_UNALIGNED_BUF_ADDR_MASK; } static inline __u64 xsk_umem__extract_offset(__u64 addr) { return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT; } static inline __u64 xsk_umem__add_offset_to_addr(__u64 addr) { return xsk_umem__extract_addr(addr) + xsk_umem__extract_offset(addr); } int xsk_umem__fd(const struct xsk_umem *umem); int xsk_socket__fd(const struct xsk_socket *xsk); #define XSK_RING_CONS__DEFAULT_NUM_DESCS 2048 #define XSK_RING_PROD__DEFAULT_NUM_DESCS 2048 #define XSK_UMEM__DEFAULT_FRAME_SHIFT 12 /* 4096 bytes */ #define XSK_UMEM__DEFAULT_FRAME_SIZE (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT) #define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0 #define XSK_UMEM__DEFAULT_FLAGS 0 struct xsk_umem_config { __u32 fill_size; __u32 comp_size; __u32 frame_size; __u32 frame_headroom; __u32 flags; __u32 tx_metadata_len; }; int xsk_attach_xdp_program(struct bpf_program *prog, int ifindex, u32 xdp_flags); void xsk_detach_xdp_program(int ifindex, u32 xdp_flags); int xsk_update_xskmap(struct bpf_map *map, struct xsk_socket *xsk, u32 index); void xsk_clear_xskmap(struct bpf_map *map); bool xsk_is_in_mode(u32 ifindex, int mode); struct xsk_socket_config { __u32 rx_size; __u32 tx_size; __u16 bind_flags; }; /* Set config to NULL to get the default configuration. */ int xsk_umem__create(struct xsk_umem **umem, void *umem_area, __u64 size, struct xsk_ring_prod *fill, struct xsk_ring_cons *comp, const struct xsk_umem_config *config); int xsk_socket__create(struct xsk_socket **xsk, int ifindex, __u32 queue_id, struct xsk_umem *umem, struct xsk_ring_cons *rx, struct xsk_ring_prod *tx, const struct xsk_socket_config *config); int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, int ifindex, __u32 queue_id, struct xsk_umem *umem, struct xsk_ring_cons *rx, struct xsk_ring_prod *tx, struct xsk_ring_prod *fill, struct xsk_ring_cons *comp, const struct xsk_socket_config *config); /* Returns 0 for success and -EBUSY if the umem is still in use. */ int xsk_umem__delete(struct xsk_umem *umem); void xsk_socket__delete(struct xsk_socket *xsk); int xsk_set_mtu(int ifindex, int mtu); #ifdef __cplusplus } /* extern "C" */ #endif #endif /* __XSK_H */