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>

4 files changed, 21 insertions, 0 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index 3799ca9b9826..c63368fc28f6 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -1372,6 +1372,8 @@ map_call_stack_common(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
         /* Set LM0 to start of key */
         if (load_lm_ptr)
                 emit_csr_wr(nfp_prog, reg_b(2 * 2), NFP_CSR_ACT_LM_ADDR0);
+        if (meta->func_id == BPF_FUNC_map_update_elem)
+                emit_csr_wr(nfp_prog, reg_b(3 * 2), NFP_CSR_ACT_LM_ADDR2);
 
         /* 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.
@@ -2326,6 +2328,7 @@ static int call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
         case BPF_FUNC_xdp_adjust_head:
                 return adjust_head(nfp_prog, meta);
         case BPF_FUNC_map_lookup_elem:
+        case BPF_FUNC_map_update_elem:
                 return map_call_stack_common(nfp_prog, meta);
         default:
                 WARN_ONCE(1, "verifier allowed unsupported function\n");
@@ -3210,6 +3213,9 @@ void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv)
                         case BPF_FUNC_map_lookup_elem:
                                 val = nfp_prog->bpf->helpers.map_lookup;
                                 break;
+                        case BPF_FUNC_map_update_elem:
+                                val = nfp_prog->bpf->helpers.map_update;
+                                break;
                         default:
                                 pr_err("relocation of unknown helper %d\n",
                                        val);
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.c b/drivers/net/ethernet/netronome/nfp/bpf/main.c
index 34e98aa6b956..db6940551b32 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.c
@@ -284,6 +284,9 @@ nfp_bpf_parse_cap_func(struct nfp_app_bpf *bpf, void __iomem *value, u32 length)
         case BPF_FUNC_map_lookup_elem:
                 bpf->helpers.map_lookup = readl(&cap->func_addr);
                 break;
+        case BPF_FUNC_map_update_elem:
+                bpf->helpers.map_update = readl(&cap->func_addr);
+                break;
         }
 
         return 0;
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h
index 0f920bf48b01..0246bd88bff3 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h
@@ -128,6 +128,7 @@ enum pkt_vec {
  *
  * @helpers:            helper addressess for various calls
  * @helpers.map_lookup:         map lookup helper address
+ * @helpers.map_update:         map update helper address
  */
 struct nfp_app_bpf {
         struct nfp_app *app;
@@ -162,6 +163,7 @@ struct nfp_app_bpf {
 
         struct {
                 u32 map_lookup;
+                u32 map_update;
         } helpers;
 };
 
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;