From fbb0499091dc1132995214a47188214602fd75c9 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 24 Jun 2014 18:36:32 +0100 Subject: ARM: 8083/1: exynos: activate the CCI on boot CPU/cluster using the MCPM loopback The Chromebook firmware doesn't enable the CCI for the boot cpu, and arguably it shouldn't have to either. Let's have the kernel handle the CCI on its own for the boot CPU the same way it does it for secondary CPUs by using the MCPM loopback. This allows to boot all 8 cores on exynos5420-peach-pit, exynos5800-peach-pi and ARM Chromebook 2. Signed-off-by: Nicolas Pitre Tested-by: Tushar Behera Reviewed-by: Kevin Hilman Tested-by: Kevin Hilman Tested-by: Doug Anderson Signed-off-by: Russell King --- arch/arm/mach-exynos/mcpm-exynos.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/arm/mach-exynos/mcpm-exynos.c') diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c index ace0ed617476..0d95bc8e49d8 100644 --- a/arch/arm/mach-exynos/mcpm-exynos.c +++ b/arch/arm/mach-exynos/mcpm-exynos.c @@ -289,6 +289,19 @@ static void __naked exynos_pm_power_up_setup(unsigned int affinity_level) "b cci_enable_port_for_self"); } +static void __init exynos_cache_off(void) +{ + if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A15) { + /* disable L2 prefetching on the Cortex-A15 */ + asm volatile( + "mcr p15, 1, %0, c15, c0, 3\n\t" + "isb\n\t" + "dsb" + : : "r" (0x400)); + } + exynos_v7_exit_coherency_flush(all); +} + static const struct of_device_id exynos_dt_mcpm_match[] = { { .compatible = "samsung,exynos5420" }, { .compatible = "samsung,exynos5800" }, @@ -332,6 +345,8 @@ static int __init exynos_mcpm_init(void) ret = mcpm_platform_register(&exynos_power_ops); if (!ret) ret = mcpm_sync_init(exynos_pm_power_up_setup); + if (!ret) + ret = mcpm_loopback(exynos_cache_off); /* turn on the CCI */ if (ret) { iounmap(ns_sram_base_addr); return ret; -- cgit v1.2.1