RE: [PATCH V2] ARM: EXYNOS: cpu hotplug: use v7_exit_coherency_flush macro for cache disabling

From: Kukjin Kim
Date: Thu May 08 2014 - 22:14:49 EST


Chanwoo Choi wrote:
>
> Hi,
>
> On 04/23/2014 02:52 PM, Leela Krishna Amudala wrote:
> > A common macro v7_exit_coherency_flush available which does the below
> tasks in
> > the seqeunce.
> > -clearing C bit
> > -clearing L1 cache
> > -exit SMP
> > -instruction and data synchronization
> >
> > So removing the local functions which does the same thing and use the
> macro instead.
> >
> > Signed-off-by: Leela Krishna Amudala <leela.krishna@xxxxxxxxxx>
> > Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>
> > ---
> > Changes since V1:
> > - removed unwanted primary_part variable in exynos_cpu_die()
> > - given more description in commit message
> > suggested by Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> >
> > arch/arm/mach-exynos/hotplug.c | 63
+---------------------------------
> ------
> > 1 file changed, 1 insertion(+), 62 deletions(-)
> >
> > diff --git a/arch/arm/mach-exynos/hotplug.c b/arch/arm/mach-
> exynos/hotplug.c
> > index 5eead53..9ca692d 100644
> > --- a/arch/arm/mach-exynos/hotplug.c
> > +++ b/arch/arm/mach-exynos/hotplug.c
> > @@ -24,56 +24,6 @@
> > #include "common.h"
> > #include "regs-pmu.h"
> >
> > -static inline void cpu_enter_lowpower_a9(void)
> > -{
> > - unsigned int v;
> > -
> > - asm volatile(
> > - " mcr p15, 0, %1, c7, c5, 0\n"
> > - " mcr p15, 0, %1, c7, c10, 4\n"
> > - /*
> > - * Turn off coherency
> > - */
> > - " mrc p15, 0, %0, c1, c0, 1\n"
> > - " bic %0, %0, %3\n"
> > - " mcr p15, 0, %0, c1, c0, 1\n"
> > - " mrc p15, 0, %0, c1, c0, 0\n"
> > - " bic %0, %0, %2\n"
> > - " mcr p15, 0, %0, c1, c0, 0\n"
> > - : "=&r" (v)
> > - : "r" (0), "Ir" (CR_C), "Ir" (0x40)
> > - : "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;
> > @@ -132,19 +82,8 @@ 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.
> > - * 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.
> > - */
> > - 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();
> > + v7_exit_coherency_flush(louis);
> >
> > platform_do_lowpower(cpu, &spurious);
> >
> >
>
> I tested this patch on Exynos3250 based on Cortex-A7 dual core.
>
> Tested-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
>
OK, will apply, thanks.

- Kukjin

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