This patch enables the 'write full line for zeros mode' feature of cortex-A9. The performance of memset() with zero is increased about 10% with this patch.
Signed-off-by: Boojin Kim <[email protected]> --- arch/arm/mach-exynos4/platsmp.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-exynos4/platsmp.c b/arch/arm/mach-exynos4/platsmp.c index d5f0f29..edf7054 100644 --- a/arch/arm/mach-exynos4/platsmp.c +++ b/arch/arm/mach-exynos4/platsmp.c @@ -90,6 +90,16 @@ static void __cpuinit exynos4_gic_secondary_init(void) __raw_writel(1, cpu_base + GIC_CPU_CTRL); } +static void enable_foz(void) +{ + u32 val; + asm volatile( + "mrc p15, 0, %0, c1, c0, 1\n" + "orr %0, %0, #(1 << 3)\n" + "mcr p15, 0, %0, c1, c0, 1" + : "=r" (val)); +} + void __cpuinit platform_secondary_init(unsigned int cpu) { /* @@ -106,6 +116,14 @@ void __cpuinit platform_secondary_init(unsigned int cpu) write_pen_release(-1); /* + * Enable write full line for zeros mode + */ + if (soc_is_exynos4210() | soc_is_exynos4212() | soc_is_exynos4412()) { + enable_foz(); + smp_call_function((void (*)(void *))enable_foz, NULL, 0); + } + + /* * Synchronise with the boot thread. */ spin_lock(&boot_lock); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
