MIPS: Emulate the new MIPS R6 BEQZC and JIC instructions

MIPS R6 uses the <R6 ldc2 opcode for the new BEQZC and JIC instructions
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

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

@@ -32,7 +32,7 @@ enum major_op {
 	sb_op, sh_op, swl_op, sw_op,
 	sdl_op, sdr_op, swr_op, cache_op,
 	ll_op, lwc1_op, lwc2_op, bc6_op = lwc2_op, pref_op,
-	lld_op, ldc1_op, ldc2_op, ld_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
 };

arch/mips/kernel/branch.c

@@ -799,6 +799,14 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
 		epc += 4 + (insn.i_format.simmediate << 2);
 		regs->cp0_epc = epc;
 		break;
+	case beqzcjic_op:
+		if (!cpu_has_mips_r6) {
+			ret = -SIGILL;
+			break;
+		}
+		/* Compact branch: BEQZC || JIC */
+		regs->cp0_epc += 8;
+		break;
 #endif
 	case cbcond0_op:
 	case cbcond1_op:

arch/mips/math-emu/cp1emu.c

@@ -678,6 +678,13 @@ 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 beqzcjic_op:
+		if (!cpu_has_mips_r6)
+			break;
+		*contpc = regs->cp0_epc + dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+
 		return 1;
 #endif
 	case cop0_op: