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-rw-r--r--tools/lib/bpf/xsk.h203
1 files changed, 203 insertions, 0 deletions
diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
new file mode 100644
index 000000000000..a497f00e2962
--- /dev/null
+++ b/tools/lib/bpf/xsk.h
@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * AF_XDP user-space access library.
+ *
+ * Copyright(c) 2018 - 2019 Intel Corporation.
+ *
+ * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#ifndef __LIBBPF_XSK_H
+#define __LIBBPF_XSK_H
+
+#include <stdio.h>
+#include <stdint.h>
+#include <linux/if_xdp.h>
+
+#include "libbpf.h"
+
+#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; \
+}
+
+DEFINE_XSK_RING(xsk_ring_prod);
+DEFINE_XSK_RING(xsk_ring_cons);
+
+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 __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 = *r->consumer + 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 = *r->producer;
+ entries = r->cached_prod - r->cached_cons;
+ }
+
+ return (entries > nb) ? nb : entries;
+}
+
+static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod *prod,
+ size_t nb, __u32 *idx)
+{
+ if (unlikely(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, size_t nb)
+{
+ /* Make sure everything has been written to the ring before signalling
+ * this to the kernel.
+ */
+ smp_wmb();
+
+ *prod->producer += nb;
+}
+
+static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons,
+ size_t nb, __u32 *idx)
+{
+ size_t entries = xsk_cons_nb_avail(cons, nb);
+
+ if (likely(entries > 0)) {
+ /* Make sure we do not speculatively read the data before
+ * we have received the packet buffers from the ring.
+ */
+ smp_rmb();
+
+ *idx = cons->cached_cons;
+ cons->cached_cons += entries;
+ }
+
+ return entries;
+}
+
+static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, size_t nb)
+{
+ *cons->consumer += nb;
+}
+
+static inline void *xsk_umem__get_data(void *umem_area, __u64 addr)
+{
+ return &((char *)umem_area)[addr];
+}
+
+LIBBPF_API int xsk_umem__fd(const struct xsk_umem *umem);
+LIBBPF_API 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 11 /* 2048 bytes */
+#define XSK_UMEM__DEFAULT_FRAME_SIZE (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT)
+#define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0
+
+struct xsk_umem_config {
+ __u32 fill_size;
+ __u32 comp_size;
+ __u32 frame_size;
+ __u32 frame_headroom;
+};
+
+/* 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. */
+LIBBPF_API 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);
+LIBBPF_API 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);
+
+/* Returns 0 for success and -EBUSY if the umem is still in use. */
+LIBBPF_API int xsk_umem__delete(struct xsk_umem *umem);
+LIBBPF_API void xsk_socket__delete(struct xsk_socket *xsk);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* __LIBBPF_XSK_H */