Verify our current constraints on the location of the key are met and generate the code for calling map lookup on the datapath.
Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com> Reviewed-by: Quentin Monnet <quentin.mon...@netronome.com> --- drivers/net/ethernet/netronome/nfp/bpf/jit.c | 51 +++++++++++++++++++++++ drivers/net/ethernet/netronome/nfp/bpf/main.h | 12 +++++- drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 39 +++++++++++++++++ 3 files changed, 100 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index 0de59f04da84..a037c0bb4185 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -1289,6 +1289,55 @@ static int adjust_head(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) return 0; } +static int +map_lookup_stack(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) +{ + struct bpf_offloaded_map *offmap; + struct nfp_bpf_map *nfp_map; + bool load_lm_ptr; + u32 ret_tgt; + s64 lm_off; + swreg tid; + + offmap = (struct bpf_offloaded_map *)meta->arg1.map_ptr; + nfp_map = offmap->dev_priv; + + /* We only have to reload LM0 if the key is not at start of stack */ + lm_off = nfp_prog->stack_depth; + lm_off += meta->arg2.var_off.value + meta->arg2.off; + load_lm_ptr = meta->arg2_var_off || lm_off; + + /* Set LM0 to start of key */ + if (load_lm_ptr) + emit_csr_wr(nfp_prog, reg_b(2 * 2), NFP_CSR_ACT_LM_ADDR0); + + /* Load map ID into a register, it should actually fit as an immediate + * but in case it doesn't deal with it here, not in the delay slots. + */ + tid = ur_load_imm_any(nfp_prog, nfp_map->tid, imm_a(nfp_prog)); + + emit_br(nfp_prog, BR_UNC, nfp_prog->bpf->helpers.map_lookup, 2); + ret_tgt = nfp_prog_current_offset(nfp_prog) + 2; + + /* Load map ID into A0 */ + wrp_mov(nfp_prog, reg_a(0), tid); + + /* Load the return address into B0 */ + wrp_immed(nfp_prog, reg_b(0), nfp_prog_current_offset(nfp_prog) + 1); + + if (!nfp_prog_confirm_current_offset(nfp_prog, ret_tgt)) + return -EINVAL; + + /* Reset the LM0 pointer */ + if (!load_lm_ptr) + return 0; + + emit_csr_wr(nfp_prog, stack_reg(nfp_prog), NFP_CSR_ACT_LM_ADDR0); + wrp_nops(nfp_prog, 3); + + return 0; +} + /* --- Callbacks --- */ static int mov_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { @@ -2028,6 +2077,8 @@ static int call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) switch (meta->insn.imm) { case BPF_FUNC_xdp_adjust_head: return adjust_head(nfp_prog, meta); + case BPF_FUNC_map_lookup_elem: + return map_lookup_stack(nfp_prog, meta); default: WARN_ONCE(1, "verifier allowed unsupported function\n"); return -EOPNOTSUPP; diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h index 9dd76bf248b1..a3b428e1181d 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h @@ -180,9 +180,12 @@ typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *); * @ptr: pointer type for memory operations * @ldst_gather_len: memcpy length gathered from load/store sequence * @paired_st: the paired store insn at the head of the sequence - * @arg2: arg2 for call instructions * @ptr_not_const: pointer is not always constant * @jmp_dst: destination info for jump instructions + * @func_id: function id for call instructions + * @arg1: arg1 for call instructions + * @arg2: arg2 for call instructions + * @arg2_var_off: arg2 changes stack offset on different paths * @off: index of first generated machine instruction (in nfp_prog.prog) * @n: eBPF instruction number * @flags: eBPF instruction extra optimization flags @@ -200,7 +203,12 @@ struct nfp_insn_meta { bool ptr_not_const; }; struct nfp_insn_meta *jmp_dst; - struct bpf_reg_state arg2; + struct { + u32 func_id; + struct bpf_reg_state arg1; + struct bpf_reg_state arg2; + bool arg2_var_off; + }; }; unsigned int off; unsigned short n; diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index d8870c2f11f3..589f56f9ea96 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -109,9 +109,11 @@ static int nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env, struct nfp_insn_meta *meta) { + const struct bpf_reg_state *reg1 = cur_regs(env) + BPF_REG_1; const struct bpf_reg_state *reg2 = cur_regs(env) + BPF_REG_2; struct nfp_app_bpf *bpf = nfp_prog->bpf; u32 func_id = meta->insn.imm; + s64 off, old_off; switch (func_id) { case BPF_FUNC_xdp_adjust_head: @@ -126,11 +128,48 @@ nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env, nfp_record_adjust_head(bpf, nfp_prog, meta, reg2); break; + + case BPF_FUNC_map_lookup_elem: + if (!bpf->helpers.map_lookup) { + pr_info("map_lookup: not supported by FW\n"); + return -EOPNOTSUPP; + } + if (reg2->type != PTR_TO_STACK) { + pr_info("map_lookup: unsupported key ptr type %d\n", + reg2->type); + return -EOPNOTSUPP; + } + if (!tnum_is_const(reg2->var_off)) { + pr_info("map_lookup: variable key pointer\n"); + return -EOPNOTSUPP; + } + + off = reg2->var_off.value + reg2->off; + if (-off % 4) { + pr_info("map_lookup: unaligned stack pointer %lld\n", + -off); + return -EOPNOTSUPP; + } + + /* Rest of the checks is only if we re-parse the same insn */ + if (!meta->func_id) + break; + + old_off = meta->arg2.var_off.value + meta->arg2.off; + meta->arg2_var_off |= off != old_off; + + if (meta->arg1.map_ptr != reg1->map_ptr) { + pr_info("map_lookup: called for different map\n"); + return -EOPNOTSUPP; + } + break; default: pr_warn("unsupported function id: %d\n", func_id); return -EOPNOTSUPP; } + meta->func_id = func_id; + meta->arg1 = *reg1; meta->arg2 = *reg2; return 0; -- 2.15.1