mips: bpf: implement jitting of BPF_ALU | BPF_ARSH | BPF_X

Jitting of BPF_K is supported already, but not BPF_X. This patch complete
the support for the latter on both MIPS and microMIPS.

Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Acked-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

arch/mips/include/asm/uasm.h

@@ -157,6 +157,7 @@ Ip_u2u1s3(_slti);
 Ip_u2u1s3(_sltiu);
 Ip_u3u1u2(_sltu);
 Ip_u2u1u3(_sra);
+Ip_u3u2u1(_srav);
 Ip_u2u1u3(_srl);
 Ip_u3u2u1(_srlv);
 Ip_u3u1u2(_subu);

arch/mips/include/uapi/asm/inst.h

@@ -371,6 +371,7 @@ enum mm_32a_minor_op {
 	mm_srl32_op = 0x040,
 	mm_srlv32_op = 0x050,
 	mm_sra_op = 0x080,
+	mm_srav_op = 0x090,
 	mm_rotr_op = 0x0c0,
 	mm_lwxs_op = 0x118,
 	mm_addu32_op = 0x150,

arch/mips/mm/uasm-micromips.c

@@ -104,6 +104,7 @@ static const struct insn insn_table_MM[insn_invalid] = {
 	[insn_sltiu]	= {M(mm_sltiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
 	[insn_sltu]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_sltu_op), RT | RS | RD},
 	[insn_sra]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_sra_op), RT | RS | RD},
+	[insn_srav]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_srav_op), RT | RS | RD},
 	[insn_srl]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_srl32_op), RT | RS | RD},
 	[insn_srlv]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_srlv32_op), RT | RS | RD},
 	[insn_rotr]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_rotr_op), RT | RS | RD},

arch/mips/mm/uasm-mips.c

@@ -171,6 +171,7 @@ static const struct insn insn_table[insn_invalid] = {
 	[insn_sltiu]	= {M(sltiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
 	[insn_sltu]	= {M(spec_op, 0, 0, 0, 0, sltu_op), RS | RT | RD},
 	[insn_sra]	= {M(spec_op, 0, 0, 0, 0, sra_op),  RT | RD | RE},
+	[insn_srav]	= {M(spec_op, 0, 0, 0, 0, srav_op), RS | RT | RD},
 	[insn_srl]	= {M(spec_op, 0, 0, 0, 0, srl_op),  RT | RD | RE},
 	[insn_srlv]	= {M(spec_op, 0, 0, 0, 0, srlv_op),  RS | RT | RD},
 	[insn_subu]	= {M(spec_op, 0, 0, 0, 0, subu_op),	RS | RT | RD},

arch/mips/mm/uasm.c

@@ -61,10 +61,10 @@ enum opcode {
 	insn_mthc0, insn_mthi, insn_mtlo, insn_mul, insn_multu, insn_nor,
 	insn_or, insn_ori, insn_pref, insn_rfe, insn_rotr, insn_sb,
 	insn_sc, insn_scd, insn_sd, insn_sh, insn_sll, insn_sllv,
-	insn_slt, insn_slti, insn_sltiu, insn_sltu, insn_sra, insn_srl,
-	insn_srlv, insn_subu, insn_sw, insn_sync, insn_syscall, insn_tlbp,
-	insn_tlbr, insn_tlbwi, insn_tlbwr, insn_wait, insn_wsbh, insn_xor,
-	insn_xori, insn_yield,
+	insn_slt, insn_slti, insn_sltiu, insn_sltu, insn_sra, insn_srav,
+	insn_srl, insn_srlv, insn_subu, insn_sw, insn_sync, insn_syscall,
+	insn_tlbp, insn_tlbr, insn_tlbwi, insn_tlbwr, insn_wait, insn_wsbh,
+	insn_xor, insn_xori, insn_yield,
 	insn_invalid /* insn_invalid must be last */
 };
 
@@ -353,6 +353,7 @@ I_u2u1s3(_slti)
 I_u2u1s3(_sltiu)
 I_u3u1u2(_sltu)
 I_u2u1u3(_sra)
+I_u3u2u1(_srav)
 I_u2u1u3(_srl)
 I_u3u2u1(_srlv)
 I_u2u1u3(_rotr)

arch/mips/net/ebpf_jit.c

@@ -854,6 +854,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
 	case BPF_ALU | BPF_MOD | BPF_X: /* ALU_REG */
 	case BPF_ALU | BPF_LSH | BPF_X: /* ALU_REG */
 	case BPF_ALU | BPF_RSH | BPF_X: /* ALU_REG */
+	case BPF_ALU | BPF_ARSH | BPF_X: /* ALU_REG */
 		src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);
 		dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
 		if (src < 0 || dst < 0)
@@ -913,6 +914,9 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
 		case BPF_RSH:
 			emit_instr(ctx, srlv, dst, dst, src);
 			break;
+		case BPF_ARSH:
+			emit_instr(ctx, srav, dst, dst, src);
+			break;
 		default:
 			pr_err("ALU_REG NOT HANDLED\n");
 			return -EINVAL;