diff options
Diffstat (limited to 'tools/testing/selftests/bpf/xsk.h')
-rw-r--r-- | tools/testing/selftests/bpf/xsk.h | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/xsk.h b/tools/testing/selftests/bpf/xsk.h new file mode 100644 index 000000000..997723b0b --- /dev/null +++ b/tools/testing/selftests/bpf/xsk.h @@ -0,0 +1,316 @@ +/* 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 <magnus.karlsson@intel.com> + */ + +#ifndef __XSK_H +#define __XSK_H + +#include <stdio.h> +#include <stdint.h> +#include <stdbool.h> +#include <linux/if_xdp.h> + +#include <bpf/libbpf.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/* This whole API has been deprecated and moved to libxdp that can be found at + * https://github.com/xdp-project/xdp-tools. The APIs are exactly the same so + * it should just be linking with libxdp instead of libbpf for this set of + * functionality. If not, please submit a bug report on the aforementioned page. + */ + +/* Load-Acquire Store-Release barriers used by the XDP socket + * library. The following macros should *NOT* be considered part of + * the xsk.h API, and is subject to change anytime. + * + * LIBRARY INTERNAL + */ + +#define __XSK_READ_ONCE(x) (*(volatile typeof(x) *)&x) +#define __XSK_WRITE_ONCE(x, v) (*(volatile typeof(x) *)&x) = (v) + +#if defined(__i386__) || defined(__x86_64__) +# define libbpf_smp_store_release(p, v) \ + do { \ + asm volatile("" : : : "memory"); \ + __XSK_WRITE_ONCE(*p, v); \ + } while (0) +# define libbpf_smp_load_acquire(p) \ + ({ \ + typeof(*p) ___p1 = __XSK_READ_ONCE(*p); \ + asm volatile("" : : : "memory"); \ + ___p1; \ + }) +#elif defined(__aarch64__) +# define libbpf_smp_store_release(p, v) \ + asm volatile ("stlr %w1, %0" : "=Q" (*p) : "r" (v) : "memory") +# define libbpf_smp_load_acquire(p) \ + ({ \ + typeof(*p) ___p1; \ + asm volatile ("ldar %w0, %1" \ + : "=r" (___p1) : "Q" (*p) : "memory"); \ + ___p1; \ + }) +#elif defined(__riscv) +# define libbpf_smp_store_release(p, v) \ + do { \ + asm volatile ("fence rw,w" : : : "memory"); \ + __XSK_WRITE_ONCE(*p, v); \ + } while (0) +# define libbpf_smp_load_acquire(p) \ + ({ \ + typeof(*p) ___p1 = __XSK_READ_ONCE(*p); \ + asm volatile ("fence r,rw" : : : "memory"); \ + ___p1; \ + }) +#endif + +#ifndef libbpf_smp_store_release +#define libbpf_smp_store_release(p, v) \ + do { \ + __sync_synchronize(); \ + __XSK_WRITE_ONCE(*p, v); \ + } while (0) +#endif + +#ifndef libbpf_smp_load_acquire +#define libbpf_smp_load_acquire(p) \ + ({ \ + typeof(*p) ___p1 = __XSK_READ_ONCE(*p); \ + __sync_synchronize(); \ + ___p1; \ + }) +#endif + +/* LIBRARY INTERNAL -- END */ + +/* 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 = libbpf_smp_load_acquire(r->consumer); + 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 = libbpf_smp_load_acquire(r->producer); + 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. + */ + libbpf_smp_store_release(prod->producer, *prod->producer + 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. + */ + libbpf_smp_store_release(cons->consumer, *cons->consumer + nb); + +} + +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; +}; + +int xsk_setup_xdp_prog_xsk(struct xsk_socket *xsk, int *xsks_map_fd); +int xsk_setup_xdp_prog(int ifindex, int *xsks_map_fd); +int xsk_socket__update_xskmap(struct xsk_socket *xsk, int xsks_map_fd); + +/* Flags for the libbpf_flags field. */ +#define XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD (1 << 0) + +struct xsk_socket_config { + __u32 rx_size; + __u32 tx_size; + __u32 libbpf_flags; + __u32 xdp_flags; + __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, + const char *ifname, __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, + const char *ifname, + __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); + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* __XSK_H */ |