From 41f0e4d041aa30507a34998c29d0b7ac0bede277 Mon Sep 17 00:00:00 2001 From: David Daney Date: Tue, 12 May 2009 12:41:53 -0700 Subject: [PATCH] MIPS: Allow R2 CPUs to turn off generation of 'ehb' instructions. Some CPUs do not need ehb instructions after writing CP0 registers. By allowing ehb generation to be overridden in cpu-feature-overrides.h, we can save a few instructions in the TLB handler hot paths. Signed-off-by: David Daney Signed-off-by: Ralf Baechle --- arch/mips/include/asm/cpu-features.h | 4 ++++ arch/mips/mm/tlbex.c | 3 ++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index c0047f8..1cba4b2 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -147,6 +147,10 @@ #define cpu_has_mips_r (cpu_has_mips32r1 | cpu_has_mips32r2 | \ cpu_has_mips64r1 | cpu_has_mips64r2) +#ifndef cpu_has_mips_r2_exec_hazard +#define cpu_has_mips_r2_exec_hazard cpu_has_mips_r2 +#endif + /* * MIPS32, MIPS64, VR5500, IDT32332, IDT32334 and maybe a few other * pre-MIPS32/MIPS53 processors have CLO, CLZ. For 64-bit kernels diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index d9a18b2..0e34faa 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -259,7 +259,8 @@ static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l, } if (cpu_has_mips_r2) { - uasm_i_ehb(p); + if (cpu_has_mips_r2_exec_hazard) + uasm_i_ehb(p); tlbw(p); return; } -- 1.8.2.3