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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>
This commit is contained in:
Abhilash Kesavan 2012-11-22 14:46:17 +09:00 committed by Kukjin Kim
parent f4a75d2eb7
commit 756e46dbaa
1 changed files with 42 additions and 3 deletions
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45
arch/arm/mach-exynos/hotplug.c
View File

@ -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);
/*