diff options
| author | Abhilash Kesavan <a.kesavan@samsung.com> | 2012-11-22 14:46:17 +0900 |
|---|---|---|
| committer | Kukjin Kim <kgene.kim@samsung.com> | 2012-11-28 07:42:04 +0900 |
| commit | 756e46dbaacf1d6d3cbefcef725e0f969afcb1e5 (patch) | |
| tree | 23d182022b10128f5c154c8469c7149bcd8c3a59 | |
| parent | f4a75d2eb7b1e2206094b901be09adb31ba63681 (diff) | |
ARM: EXYNOS: fix the hotplug for Cortex-A15
The sequence of cpu_enter_lowpower() for Cortex-A15 is
different from the sequence for Cortex-A9. This patch
implements cpu_enter_lowpower() for EXYNOS5 SoC which
has Cortex-A15 cores.
Basded on original patch has been submitted by Changhwan Youn
Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
[kgene.kim@samsung.com: use flush_cache_louis() instead of
flush_cache_all() as per Lorenzo and Santosh's suggestion]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
| -rw-r--r-- | arch/arm/mach-exynos/hotplug.c | 45 |
1 files changed, 42 insertions, 3 deletions
diff --git a/arch/arm/mach-exynos/hotplug.c b/arch/arm/mach-exynos/hotplug.c index f4d7dd20cdac..c3f825b27947 100644 --- a/arch/arm/mach-exynos/hotplug.c +++ b/arch/arm/mach-exynos/hotplug.c @@ -20,10 +20,11 @@ #include <asm/smp_plat.h> #include <mach/regs-pmu.h> +#include <plat/cpu.h> #include "common.h" -static inline void cpu_enter_lowpower(void) +static inline void cpu_enter_lowpower_a9(void) { unsigned int v; @@ -45,6 +46,35 @@ static inline void cpu_enter_lowpower(void) : "cc"); } +static inline void cpu_enter_lowpower_a15(void) +{ + unsigned int v; + + asm volatile( + " mrc p15, 0, %0, c1, c0, 0\n" + " bic %0, %0, %1\n" + " mcr p15, 0, %0, c1, c0, 0\n" + : "=&r" (v) + : "Ir" (CR_C) + : "cc"); + + flush_cache_louis(); + + asm volatile( + /* + * Turn off coherency + */ + " mrc p15, 0, %0, c1, c0, 1\n" + " bic %0, %0, %1\n" + " mcr p15, 0, %0, c1, c0, 1\n" + : "=&r" (v) + : "Ir" (0x40) + : "cc"); + + isb(); + dsb(); +} + static inline void cpu_leave_lowpower(void) { unsigned int v; @@ -103,11 +133,20 @@ static inline void platform_do_lowpower(unsigned int cpu, int *spurious) void __ref exynos_cpu_die(unsigned int cpu) { int spurious = 0; + int primary_part = 0; /* - * we're ready for shutdown now, so do it + * we're ready for shutdown now, so do it. + * Exynos4 is A9 based while Exynos5 is A15; check the CPU part + * number by reading the Main ID register and then perform the + * appropriate sequence for entering low power. */ - cpu_enter_lowpower(); + asm("mrc p15, 0, %0, c0, c0, 0" : "=r"(primary_part) : : "cc"); + if ((primary_part & 0xfff0) == 0xc0f0) + cpu_enter_lowpower_a15(); + else + cpu_enter_lowpower_a9(); + platform_do_lowpower(cpu, &spurious); /* |