nfp: bpf: add offload of TC direct action mode

Add offload of TC in direct action mode.  We just need
to provide appropriate checks in the verifier and
a new outro block to translate the exit codes to what
data path expects

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_bpf.h b/drivers/net/ethernet/netronome/nfp/nfp_bpf.h
index adbe0235d98eccba15218f129d88d5e68a6f6216..fc220cd04115409b107f1bac643b664eb2f70d58 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_bpf.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_bpf.h
@@ -61,6 +61,7 @@ enum static_regs {
 enum nfp_bpf_action_type {
        NN_ACT_TC_DROP,
        NN_ACT_TC_REDIR,
+       NN_ACT_DIRECT,
 };
 
 /* Software register representation, hardware encoding in asm.h */

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_bpf_jit.c b/drivers/net/ethernet/netronome/nfp/nfp_bpf_jit.c
index 434bef975c58d6a363999fc89247006c0eda4816..3de819acd68c0b7afae479f86deb550554e613e7 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_bpf_jit.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_bpf_jit.c
@@ -321,6 +321,16 @@ __emit_br(struct nfp_prog *nfp_prog, enum br_mask mask, enum br_ev_pip ev_pip,
        nfp_prog_push(nfp_prog, insn);
 }
 
+static void emit_br_def(struct nfp_prog *nfp_prog, u16 addr, u8 defer)
+{
+       if (defer > 2) {
+               pr_err("BUG: branch defer out of bounds %d\n", defer);
+               nfp_prog->error = -EFAULT;
+               return;
+       }
+       __emit_br(nfp_prog, BR_UNC, BR_EV_PIP_UNCOND, BR_CSS_NONE, addr, defer);
+}
+
 static void
 emit_br(struct nfp_prog *nfp_prog, enum br_mask mask, u16 addr, u8 defer)
 {
@@ -1465,9 +1475,65 @@ static void nfp_outro_tc_legacy(struct nfp_prog *nfp_prog)
                      SHF_SC_L_SHF, 16);
 }
 
+static void nfp_outro_tc_da(struct nfp_prog *nfp_prog)
+{
+       /* TC direct-action mode:
+        *   0,1   ok        NOT SUPPORTED[1]
+        *   2   drop  0x22 -> drop,  count as stat1
+        *   4,5 nuke  0x02 -> drop
+        *   7  redir  0x44 -> redir, count as stat2
+        *   * unspec  0x11 -> pass,  count as stat0
+        *
+        * [1] We can't support OK and RECLASSIFY because we can't tell TC
+        *     the exact decision made.  We are forced to support UNSPEC
+        *     to handle aborts so that's the only one we handle for passing
+        *     packets up the stack.
+        */
+       /* Target for aborts */
+       nfp_prog->tgt_abort = nfp_prog_current_offset(nfp_prog);
+
+       emit_br_def(nfp_prog, nfp_prog->tgt_done, 2);
+
+       emit_alu(nfp_prog, reg_a(0),
+                reg_none(), ALU_OP_NONE, NFP_BPF_ABI_FLAGS);
+       emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_imm(0x11), SHF_SC_L_SHF, 16);
+
+       /* Target for normal exits */
+       nfp_prog->tgt_out = nfp_prog_current_offset(nfp_prog);
+
+       /* if R0 > 7 jump to abort */
+       emit_alu(nfp_prog, reg_none(), reg_imm(7), ALU_OP_SUB, reg_b(0));
+       emit_br(nfp_prog, BR_BLO, nfp_prog->tgt_abort, 0);
+       emit_alu(nfp_prog, reg_a(0),
+                reg_none(), ALU_OP_NONE, NFP_BPF_ABI_FLAGS);
+
+       wrp_immed(nfp_prog, reg_b(2), 0x41221211);
+       wrp_immed(nfp_prog, reg_b(3), 0x41001211);
+
+       emit_shf(nfp_prog, reg_a(1),
+                reg_none(), SHF_OP_NONE, reg_b(0), SHF_SC_L_SHF, 2);
+
+       emit_alu(nfp_prog, reg_none(), reg_a(1), ALU_OP_OR, reg_imm(0));
+       emit_shf(nfp_prog, reg_a(2),
+                reg_imm(0xf), SHF_OP_AND, reg_b(2), SHF_SC_R_SHF, 0);
+
+       emit_alu(nfp_prog, reg_none(), reg_a(1), ALU_OP_OR, reg_imm(0));
+       emit_shf(nfp_prog, reg_b(2),
+                reg_imm(0xf), SHF_OP_AND, reg_b(3), SHF_SC_R_SHF, 0);
+
+       emit_br_def(nfp_prog, nfp_prog->tgt_done, 2);
+
+       emit_shf(nfp_prog, reg_b(2),
+                reg_a(2), SHF_OP_OR, reg_b(2), SHF_SC_L_SHF, 4);
+       emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_b(2), SHF_SC_L_SHF, 16);
+}
+
 static void nfp_outro(struct nfp_prog *nfp_prog)
 {
        switch (nfp_prog->act) {
+       case NN_ACT_DIRECT:
+               nfp_outro_tc_da(nfp_prog);
+               break;
        case NN_ACT_TC_DROP:
        case NN_ACT_TC_REDIR:
                nfp_outro_tc_legacy(nfp_prog);

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c b/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c
index ef6775b54168ac4b932b4d98788a71bb5d358a9d..144cae87f63a19b441f385661f2705b37d826a71 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c
@@ -86,7 +86,16 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_prog,
                return -EINVAL;
        }
 
-       if (reg0->imm != 0 && (reg0->imm & ~0U) != ~0U) {
+       if (nfp_prog->act != NN_ACT_DIRECT &&
+           reg0->imm != 0 && (reg0->imm & ~0U) != ~0U) {
+               pr_info("unsupported exit state: %d, imm: %llx\n",
+                       reg0->type, reg0->imm);
+               return -EINVAL;
+       }
+
+       if (nfp_prog->act == NN_ACT_DIRECT && reg0->imm <= TC_ACT_REDIRECT &&
+           reg0->imm != TC_ACT_SHOT && reg0->imm != TC_ACT_STOLEN &&
+           reg0->imm != TC_ACT_QUEUED) {
                pr_info("unsupported exit state: %d, imm: %llx\n",
                        reg0->type, reg0->imm);
                return -EINVAL;

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c b/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c
index 1ec8e5b74651c1f5c320b91bda564ba180354217..43f42f842eda94a4d4324329d521375d05573f1a 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c
@@ -112,8 +112,12 @@ nfp_net_bpf_get_act(struct nfp_net *nn, struct tc_cls_bpf_offload *cls_bpf)
        LIST_HEAD(actions);
 
        /* TC direct action */
-       if (cls_bpf->exts_integrated)
+       if (cls_bpf->exts_integrated) {
+               if (tc_no_actions(cls_bpf->exts))
+                       return NN_ACT_DIRECT;
+
                return -ENOTSUPP;
+       }
 
        /* TC legacy mode */
        if (!tc_single_action(cls_bpf->exts))