From e65650f291ee72fc578d6346080fc4699204ef2c Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Fri, 1 Nov 2019 12:03:45 +0100 Subject: bpf: Implement map_gen_lookup() callback for XSKMAP Inline the xsk_map_lookup_elem() via implementing the map_gen_lookup() callback. This results in emitting the bpf instructions in place of bpf_map_lookup_elem() helper call and better performance of bpf programs. Signed-off-by: Maciej Fijalkowski Signed-off-by: Daniel Borkmann Acked-by: Jonathan Lemon Link: https://lore.kernel.org/bpf/20191101110346.15004-3-bjorn.topel@gmail.com --- kernel/bpf/xskmap.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'kernel') diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c index edcbd863650e..554939f78b83 100644 --- a/kernel/bpf/xskmap.c +++ b/kernel/bpf/xskmap.c @@ -163,6 +163,22 @@ struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map, u32 key) return xs; } +static u32 xsk_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) +{ + const int ret = BPF_REG_0, mp = BPF_REG_1, index = BPF_REG_2; + struct bpf_insn *insn = insn_buf; + + *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); + *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5); + *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(sizeof(struct xsk_sock *))); + *insn++ = BPF_ALU64_IMM(BPF_ADD, mp, offsetof(struct xsk_map, xsk_map)); + *insn++ = BPF_ALU64_REG(BPF_ADD, ret, mp); + *insn++ = BPF_LDX_MEM(BPF_SIZEOF(struct xsk_sock *), ret, ret, 0); + *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); + *insn++ = BPF_MOV64_IMM(ret, 0); + return insn - insn_buf; +} + int __xsk_map_redirect(struct bpf_map *map, struct xdp_buff *xdp, struct xdp_sock *xs) { @@ -303,6 +319,7 @@ const struct bpf_map_ops xsk_map_ops = { .map_free = xsk_map_free, .map_get_next_key = xsk_map_get_next_key, .map_lookup_elem = xsk_map_lookup_elem, + .map_gen_lookup = xsk_map_gen_lookup, .map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only, .map_update_elem = xsk_map_update_elem, .map_delete_elem = xsk_map_delete_elem, -- cgit v1.2.3