MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructions

MIPS R6 uses the <R6 sdc2 opcode for the new BNEZC and JIALC instructions

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

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

@@ -34,7 +34,7 @@ enum major_op {
 	ll_op, lwc1_op, lwc2_op, bc6_op = lwc2_op, pref_op,
 	lld_op, ldc1_op, ldc2_op, beqzcjic_op = ldc2_op, ld_op,
 	sc_op, swc1_op, swc2_op, balc6_op = swc2_op, major_3b_op,
-	scd_op, sdc1_op, sdc2_op, sd_op
+	scd_op, sdc1_op, sdc2_op, bnezcjialc_op = sdc2_op, sd_op
 };
 
 /*

arch/mips/kernel/branch.c

@@ -807,6 +807,16 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
 		/* Compact branch: BEQZC || JIC */
 		regs->cp0_epc += 8;
 		break;
+	case bnezcjialc_op:
+		if (!cpu_has_mips_r6) {
+			ret = -SIGILL;
+			break;
+		}
+		/* Compact branch: BNEZC || JIALC */
+		if (insn.i_format.rs)
+			regs->regs[31] = epc + 4;
+		regs->cp0_epc += 8;
+		break;
 #endif
 	case cbcond0_op:
 	case cbcond1_op:

arch/mips/math-emu/cp1emu.c

@@ -685,6 +685,15 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
 			dec_insn.next_pc_inc;
 
+		return 1;
+	case bnezcjialc_op:
+		if (!cpu_has_mips_r6)
+			break;
+		if (!insn.i_format.rs)
+			regs->regs[31] = regs->cp0_epc + 4;
+		*contpc = regs->cp0_epc + dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+
 		return 1;
 #endif
 	case cop0_op: