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authorMarkos Chandras <markos.chandras@imgtec.com>2014-11-26 15:08:52 +0100
committerMarkos Chandras <markos.chandras@imgtec.com>2015-02-17 16:37:34 +0100
commitc893ce38b265d5787d03850b36221f595b224538 (patch)
tree9ebc726517a4eb3aee5c3a07f0f531f0704fc97a /arch
parentMIPS: Emulate the new MIPS R6 branch compact (BC) instruction (diff)
downloadlinux-c893ce38b265d5787d03850b36221f595b224538.tar.xz
linux-c893ce38b265d5787d03850b36221f595b224538.zip
MIPS: Emulate the new MIPS R6 BOVC, BEQC and BEQZALC instructions
MIPS R6 uses the <R6 ADDI opcode for the new BOVC, BEQC and BEQZALC instructions. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/include/uapi/asm/inst.h2
-rw-r--r--arch/mips/kernel/branch.c11
-rw-r--r--arch/mips/math-emu/cp1emu.c9
3 files changed, 21 insertions, 1 deletions
diff --git a/arch/mips/include/uapi/asm/inst.h b/arch/mips/include/uapi/asm/inst.h
index 9ce5e34b9c64..782af0f83421 100644
--- a/arch/mips/include/uapi/asm/inst.h
+++ b/arch/mips/include/uapi/asm/inst.h
@@ -21,7 +21,7 @@
enum major_op {
spec_op, bcond_op, j_op, jal_op,
beq_op, bne_op, blez_op, bgtz_op,
- addi_op, addiu_op, slti_op, sltiu_op,
+ addi_op, cbcond0_op = addi_op, addiu_op, slti_op, sltiu_op,
andi_op, ori_op, xori_op, lui_op,
cop0_op, cop1_op, cop2_op, cop1x_op,
beql_op, bnel_op, blezl_op, bgtzl_op,
diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index 1a0a30e16684..80a073ced200 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c
@@ -790,6 +790,17 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
regs->cp0_epc += 8;
break;
#endif
+ case cbcond0_op:
+ /* Only valid for MIPS R6 */
+ if (!cpu_has_mips_r6) {
+ ret = -SIGILL;
+ break;
+ }
+ /* Compact branches: bovc, beqc, beqzalc */
+ if (insn.i_format.rt && !insn.i_format.rs)
+ regs->regs[31] = epc + 4;
+ regs->cp0_epc += 8;
+ break;
}
return ret;
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 7f373a2858b5..c115d969664b 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -623,6 +623,15 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
+ case cbcond0_op:
+ if (!cpu_has_mips_r6)
+ break;
+ if (insn.i_format.rt && !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;
#ifdef CONFIG_CPU_CAVIUM_OCTEON
case lwc2_op: /* This is bbit0 on Octeon */
if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)