nfp: bpf: tabularize generations of compare operations

There are quite a few compare instructions now, use a table
to translate BPF instruction code to NFP instruction parameters
instead of parameterizing helpers.  This saves LOC and makes
future extensions easier.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

drivers/net/ethernet/netronome/nfp/bpf/jit.c

@@ -1214,45 +1214,79 @@ wrp_test_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
 	return 0;
 }
 
-static int
-wrp_cmp_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
-	    enum br_mask br_mask, bool swap)
+static const struct jmp_code_map {
+	enum br_mask br_mask;
+	bool swap;
+} jmp_code_map[] = {
+	[BPF_JGT >> 4]	= { BR_BLO, true },
+	[BPF_JGE >> 4]	= { BR_BHS, false },
+	[BPF_JLT >> 4]	= { BR_BLO, false },
+	[BPF_JLE >> 4]	= { BR_BHS, true },
+	[BPF_JSGT >> 4]	= { BR_BLT, true },
+	[BPF_JSGE >> 4]	= { BR_BGE, false },
+	[BPF_JSLT >> 4]	= { BR_BLT, false },
+	[BPF_JSLE >> 4]	= { BR_BGE, true },
+};
+
+static const struct jmp_code_map *nfp_jmp_code_get(struct nfp_insn_meta *meta)
+{
+	unsigned int op;
+
+	op = BPF_OP(meta->insn.code) >> 4;
+	/* br_mask of 0 is BR_BEQ which we don't use in jump code table */
+	if (WARN_ONCE(op >= ARRAY_SIZE(jmp_code_map) ||
+		      !jmp_code_map[op].br_mask,
+		      "no code found for jump instruction"))
+		return NULL;
+
+	return &jmp_code_map[op];
+}
+
+static int cmp_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {
 	const struct bpf_insn *insn = &meta->insn;
 	u64 imm = insn->imm; /* sign extend */
+	const struct jmp_code_map *code;
 	u8 reg = insn->dst_reg * 2;
 	swreg tmp_reg;
 
+	code = nfp_jmp_code_get(meta);
+	if (!code)
+		return -EINVAL;
+
 	tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog));
-	if (!swap)
+	if (!code->swap)
 		emit_alu(nfp_prog, reg_none(), reg_a(reg), ALU_OP_SUB, tmp_reg);
 	else
 		emit_alu(nfp_prog, reg_none(), tmp_reg, ALU_OP_SUB, reg_a(reg));
 
 	tmp_reg = ur_load_imm_any(nfp_prog, imm >> 32, imm_b(nfp_prog));
-	if (!swap)
+	if (!code->swap)
 		emit_alu(nfp_prog, reg_none(),
 			 reg_a(reg + 1), ALU_OP_SUB_C, tmp_reg);
 	else
 		emit_alu(nfp_prog, reg_none(),
 			 tmp_reg, ALU_OP_SUB_C, reg_a(reg + 1));
 
-	emit_br(nfp_prog, br_mask, insn->off, 0);
+	emit_br(nfp_prog, code->br_mask, insn->off, 0);
 
 	return 0;
 }
 
-static int
-wrp_cmp_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
-	    enum br_mask br_mask, bool swap)
+static int cmp_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {
 	const struct bpf_insn *insn = &meta->insn;
+	const struct jmp_code_map *code;
 	u8 areg, breg;
 
+	code = nfp_jmp_code_get(meta);
+	if (!code)
+		return -EINVAL;
+
 	areg = insn->dst_reg * 2;
 	breg = insn->src_reg * 2;
 
-	if (swap) {
+	if (code->swap) {
 		areg ^= breg;
 		breg ^= areg;
 		areg ^= breg;
@@ -1261,7 +1295,7 @@ wrp_cmp_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
 	emit_alu(nfp_prog, reg_none(), reg_a(areg), ALU_OP_SUB, reg_b(breg));
 	emit_alu(nfp_prog, reg_none(),
 		 reg_a(areg + 1), ALU_OP_SUB_C, reg_b(breg + 1));
-	emit_br(nfp_prog, br_mask, insn->off, 0);
+	emit_br(nfp_prog, code->br_mask, insn->off, 0);
 
 	return 0;
 }
@@ -2283,46 +2317,6 @@ static int jeq_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 	return 0;
 }
 
-static int jgt_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BLO, true);
-}
-
-static int jge_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BHS, false);
-}
-
-static int jlt_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BLO, false);
-}
-
-static int jle_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BHS, true);
-}
-
-static int jsgt_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BLT, true);
-}
-
-static int jsge_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BGE, false);
-}
-
-static int jslt_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BLT, false);
-}
-
-static int jsle_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_imm(nfp_prog, meta, BR_BGE, true);
-}
-
 static int jset_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {
 	const struct bpf_insn *insn = &meta->insn;
@@ -2392,46 +2386,6 @@ static int jeq_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 	return 0;
 }
 
-static int jgt_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BLO, true);
-}
-
-static int jge_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BHS, false);
-}
-
-static int jlt_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BLO, false);
-}
-
-static int jle_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BHS, true);
-}
-
-static int jsgt_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BLT, true);
-}
-
-static int jsge_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BGE, false);
-}
-
-static int jslt_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BLT, false);
-}
-
-static int jsle_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
-{
-	return wrp_cmp_reg(nfp_prog, meta, BR_BGE, true);
-}
-
 static int jset_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {
 	return wrp_test_reg(nfp_prog, meta, ALU_OP_AND, BR_BNE);
@@ -2520,25 +2474,25 @@ static const instr_cb_t instr_cb[256] = {
 	[BPF_ST | BPF_MEM | BPF_DW] =	mem_st8,
 	[BPF_JMP | BPF_JA | BPF_K] =	jump,
 	[BPF_JMP | BPF_JEQ | BPF_K] =	jeq_imm,
-	[BPF_JMP | BPF_JGT | BPF_K] =	jgt_imm,
-	[BPF_JMP | BPF_JGE | BPF_K] =	jge_imm,
-	[BPF_JMP | BPF_JLT | BPF_K] =	jlt_imm,
-	[BPF_JMP | BPF_JLE | BPF_K] =	jle_imm,
-	[BPF_JMP | BPF_JSGT | BPF_K] =  jsgt_imm,
-	[BPF_JMP | BPF_JSGE | BPF_K] =  jsge_imm,
-	[BPF_JMP | BPF_JSLT | BPF_K] =  jslt_imm,
-	[BPF_JMP | BPF_JSLE | BPF_K] =  jsle_imm,
+	[BPF_JMP | BPF_JGT | BPF_K] =	cmp_imm,
+	[BPF_JMP | BPF_JGE | BPF_K] =	cmp_imm,
+	[BPF_JMP | BPF_JLT | BPF_K] =	cmp_imm,
+	[BPF_JMP | BPF_JLE | BPF_K] =	cmp_imm,
+	[BPF_JMP | BPF_JSGT | BPF_K] =  cmp_imm,
+	[BPF_JMP | BPF_JSGE | BPF_K] =  cmp_imm,
+	[BPF_JMP | BPF_JSLT | BPF_K] =  cmp_imm,
+	[BPF_JMP | BPF_JSLE | BPF_K] =  cmp_imm,
 	[BPF_JMP | BPF_JSET | BPF_K] =	jset_imm,
 	[BPF_JMP | BPF_JNE | BPF_K] =	jne_imm,
 	[BPF_JMP | BPF_JEQ | BPF_X] =	jeq_reg,
-	[BPF_JMP | BPF_JGT | BPF_X] =	jgt_reg,
-	[BPF_JMP | BPF_JGE | BPF_X] =	jge_reg,
-	[BPF_JMP | BPF_JLT | BPF_X] =	jlt_reg,
-	[BPF_JMP | BPF_JLE | BPF_X] =	jle_reg,
-	[BPF_JMP | BPF_JSGT | BPF_X] =  jsgt_reg,
-	[BPF_JMP | BPF_JSGE | BPF_X] =  jsge_reg,
-	[BPF_JMP | BPF_JSLT | BPF_X] =  jslt_reg,
-	[BPF_JMP | BPF_JSLE | BPF_X] =  jsle_reg,
+	[BPF_JMP | BPF_JGT | BPF_X] =	cmp_reg,
+	[BPF_JMP | BPF_JGE | BPF_X] =	cmp_reg,
+	[BPF_JMP | BPF_JLT | BPF_X] =	cmp_reg,
+	[BPF_JMP | BPF_JLE | BPF_X] =	cmp_reg,
+	[BPF_JMP | BPF_JSGT | BPF_X] =  cmp_reg,
+	[BPF_JMP | BPF_JSGE | BPF_X] =  cmp_reg,
+	[BPF_JMP | BPF_JSLT | BPF_X] =  cmp_reg,
+	[BPF_JMP | BPF_JSLE | BPF_X] =  cmp_reg,
 	[BPF_JMP | BPF_JSET | BPF_X] =	jset_reg,
 	[BPF_JMP | BPF_JNE | BPF_X] =	jne_reg,
 	[BPF_JMP | BPF_CALL] =		call,