From 84fef630127aa90ef547ddd018d3dc47b1e79a1e Mon Sep 17 00:00:00 2001
From: Markos Chandras <markos.chandras@imgtec.com>
Date: Wed, 26 Nov 2014 15:43:11 +0000
Subject: [PATCH] MIPS: Emulate the new MIPS R6 BALC instruction
MIPS R6 uses the <R6 swc2 opcode for the new BALC instructions.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
---
arch/mips/include/uapi/asm/inst.h | 2 +-
arch/mips/kernel/branch.c | 10 ++++++++++
arch/mips/math-emu/cp1emu.c | 8 ++++++++
3 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/arch/mips/include/uapi/asm/inst.h b/arch/mips/include/uapi/asm/inst.h
index 78335414b18a0..32063c52f24b9 100644
--- a/arch/mips/include/uapi/asm/inst.h
+++ b/arch/mips/include/uapi/asm/inst.h
@@ -33,7 +33,7 @@ enum major_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,
- sc_op, swc1_op, swc2_op, major_3b_op,
+ sc_op, swc1_op, swc2_op, balc6_op = swc2_op, major_3b_op,
scd_op, sdc1_op, sdc2_op, sd_op
};
diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index 37c7527573467..1f28724d23e5f 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c
@@ -789,6 +789,16 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
}
regs->cp0_epc += 8;
break;
+ case balc6_op:
+ if (!cpu_has_mips_r6) {
+ ret = -SIGILL;
+ break;
+ }
+ /* Compact branch: BALC */
+ regs->regs[31] = epc + 4;
+ epc += 4 + (insn.i_format.simmediate << 2);
+ regs->cp0_epc = epc;
+ break;
#endif
case cbcond0_op:
case cbcond1_op:
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 0d8407b51470c..d732100c99f0c 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -670,6 +670,14 @@ 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 balc6_op:
+ if (!cpu_has_mips_r6)
+ break;
+ 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:
--
2.30.2