nfp: bpf: add map updates from the datapath

Support calling map_update_elem() from the datapath programs
by calling into FW-provided helper.  Value pointer is passed
in LM pointer #2.  Keeping track of old state for arg3 is not
necessary, since LM pointer #2 will be always loaded in this
case, the trivial optimization for value at the bottom of the
stack can't be done here.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
index acfc4d798116..482a0ce6e755 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -167,6 +167,7 @@ nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env,
 {
 	const struct bpf_reg_state *reg1 = cur_regs(env) + BPF_REG_1;
 	const struct bpf_reg_state *reg2 = cur_regs(env) + BPF_REG_2;
+	const struct bpf_reg_state *reg3 = cur_regs(env) + BPF_REG_3;
 	struct nfp_app_bpf *bpf = nfp_prog->bpf;
 	u32 func_id = meta->insn.imm;
 
@@ -191,6 +192,15 @@ nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env,
 					  meta->func_id ? &meta->arg2 : NULL))
 			return -EOPNOTSUPP;
 		break;
+
+	case BPF_FUNC_map_update_elem:
+		if (!nfp_bpf_map_call_ok("map_update", env, meta,
+					 bpf->helpers.map_update, reg1) ||
+		    !nfp_bpf_stack_arg_ok("map_update", env, reg2,
+					  meta->func_id ? &meta->arg2 : NULL) ||
+		    !nfp_bpf_stack_arg_ok("map_update", env, reg3, NULL))
+			return -EOPNOTSUPP;
+		break;
 	default:
 		pr_vlog(env, "unsupported function id: %d\n", func_id);
 		return -EOPNOTSUPP;