From 8467ca0122e20f3f8e73d34907b8b30461af5d4e Mon Sep 17 00:00:00 2001 From: Markos Chandras Date: Wed, 26 Nov 2014 13:56:51 +0000 Subject: [PATCH] MIPS: Emulate the new MIPS R6 branch compact (BC) instruction MIPS R6 uses the --- arch/mips/include/uapi/asm/inst.h | 2 +- arch/mips/kernel/branch.c | 9 +++++++++ arch/mips/math-emu/cp1emu.c | 13 +++++++++++++ 3 files changed, 23 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/uapi/asm/inst.h b/arch/mips/include/uapi/asm/inst.h index 19d3bc1..9ce5e34 100644 --- a/arch/mips/include/uapi/asm/inst.h +++ b/arch/mips/include/uapi/asm/inst.h @@ -31,7 +31,7 @@ enum major_op { lbu_op, lhu_op, lwr_op, lwu_op, sb_op, sh_op, swl_op, sw_op, sdl_op, sdr_op, swr_op, cache_op, - ll_op, lwc1_op, lwc2_op, pref_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, scd_op, sdc1_op, sdc2_op, sd_op diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c index cd880b9..1a0a30e 100644 --- a/arch/mips/kernel/branch.c +++ b/arch/mips/kernel/branch.c @@ -780,6 +780,15 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, epc += 8; regs->cp0_epc = epc; break; +#else + case bc6_op: + /* Only valid for MIPS R6 */ + if (!cpu_has_mips_r6) { + ret = -SIGILL; + break; + } + regs->cp0_epc += 8; + break; #endif } diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index d6d67e2..7f373a2 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -648,6 +648,19 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, else *contpc = regs->cp0_epc + 8; return 1; +#else + case bc6_op: + /* + * Only valid for MIPS R6 but we can still end up + * here from a broken userland so just tell emulator + * this is not a branch and let it break later on. + */ + 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: case cop1_op: -- 2.7.4