Kukjin Kim wrote:
>
> From: Changhwan Youn <chaos.youn@xxxxxxxxxxx>
>
> This patch updates CPU hotplug implementation to reduce CPU power
> consumption
> and will turn off the CPU power when CPU1 is unplugged while previous CPU
> hotplug
> used CPU idle.
> This patch removes init memory freeing code to use CPU boot code when CPU1
is
> plugged-in again and adds vfp_enable() call to allow to access CP10 and
CP11.
>
> Signed-off-by: Changhwan Youn <chaos.youn@xxxxxxxxxxx>
> Signed-off-by: Kukjin Kim <kgene.kim@xxxxxxxxxxx>
> Cc: Russell King <rmk@xxxxxxxxxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: Colin Cross <ccross@xxxxxxxxxxx>
Cc: Erik Gilling <konkers@xxxxxxxxxxx>
Cc: Olof Johansson <olof@xxxxxxxxx>
Hi all,
Please check changing of arch/arm/mm/init.c and arch/arm/vfp/vfpmodule.c.
- Removed init memory freeing code to use CPU boot code when CPU1 is
plugged-in again.
- Added vfp_enable() call to allow to access CP10 and CP11.
> ---
> arch/arm/mach-s5pv310/hotplug.c | 12 +++++++-----
> arch/arm/mach-s5pv310/platsmp.c | 34
> ++++++++++++++++++++++++++++++++++
> arch/arm/mm/init.c | 2 ++
> arch/arm/vfp/vfpmodule.c | 2 +-
> 4 files changed, 44 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/mach-s5pv310/hotplug.c
b/arch/arm/mach-s5pv310/hotplug.c
> index 03652c3..0e188fe 100644
> --- a/arch/arm/mach-s5pv310/hotplug.c
> +++ b/arch/arm/mach-s5pv310/hotplug.c
> @@ -14,9 +14,12 @@
> #include <linux/errno.h>
> #include <linux/smp.h>
> #include <linux/completion.h>
> +#include <linux/io.h>
>
> #include <asm/cacheflush.h>
>
> +#include <mach/regs-pmu.h>
> +
> extern volatile int pen_release;
>
> static DECLARE_COMPLETION(cpu_killed);
> @@ -61,12 +64,11 @@ static inline void cpu_leave_lowpower(void)
>
> static inline void platform_do_lowpower(unsigned int cpu)
> {
> - /*
> - * there is no power-control hardware on this platform, so all
> - * we can do is put the core into WFI; this is safe as the calling
> - * code will have already disabled interrupts
> - */
> for (;;) {
> + /* make cpu1 to be turned off at next WFI command */
> + if (cpu == 1)
> + __raw_writel(0, S5PV310_ARM_CORE1_CONF);
> +
> /*
> * here's the WFI
> */
> diff --git a/arch/arm/mach-s5pv310/platsmp.c
b/arch/arm/mach-s5pv310/platsmp.c
> index d357c19..d10c4ad 100644
> --- a/arch/arm/mach-s5pv310/platsmp.c
> +++ b/arch/arm/mach-s5pv310/platsmp.c
> @@ -28,8 +28,10 @@
>
> #include <mach/hardware.h>
> #include <mach/regs-clock.h>
> +#include <mach/regs-pmu.h>
>
> extern void s5pv310_secondary_startup(void);
> +extern void vfp_enable(void *unused);
>
> /*
> * control for which core is the next to come out of the secondary
> @@ -47,6 +49,10 @@ static DEFINE_SPINLOCK(boot_lock);
>
> void __cpuinit platform_secondary_init(unsigned int cpu)
> {
> +#ifdef CONFIG_VFP
> + vfp_enable(NULL);
> +#endif
> +
> trace_hardirqs_off();
>
> /*
> @@ -92,6 +98,27 @@ int __cpuinit boot_secondary(unsigned int cpu, struct
> task_struct *idle)
> __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
> outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
>
> + if (!(__raw_readl(S5PV310_ARM_CORE1_STAT) &
> S5PV310_CORE_PWR_EN)) {
> + __raw_writel(S5PV310_CORE_PWR_EN,
> + S5PV310_ARM_CORE1_CONF);
> +
> + timeout = 10;
> +
> + /* wait max 10 ms until cpu1 is on */
> + while ((__raw_readl(S5PV310_ARM_CORE1_STAT)
> + & S5PV310_CORE_PWR_EN) !=
> S5PV310_CORE_PWR_EN) {
> + if (timeout-- == 0)
> + break;
> +
> + mdelay(1);
> + }
> +
> + if (timeout == 0) {
> + printk(KERN_ERR "cpu1 power-up failed");
> + return -ETIMEDOUT;
> + }
> + }
> +
> /*
> * Send the secondary CPU a soft interrupt, thereby causing
> * the boot monitor to read the system wide flags register,
> @@ -102,6 +129,13 @@ int __cpuinit boot_secondary(unsigned int cpu, struct
> task_struct *idle)
> timeout = jiffies + (1 * HZ);
> while (time_before(jiffies, timeout)) {
> smp_rmb();
> +
> + if (!__raw_readl(S5P_VA_SYSRAM)) {
> +
> __raw_writel(BSYM(virt_to_phys(s5pv310_secondary_startup)),
> + S5P_VA_SYSRAM);
> + smp_cross_call(cpumask_of(cpu));
> + }
> +
> if (pen_release == -1)
> break;
>
> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> index 7185b00..57c4c5c 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -589,10 +589,12 @@ void free_initmem(void)
> "TCM link");
> #endif
>
> +#ifndef CONFIG_HOTPLUG_CPU
> if (!machine_is_integrator() && !machine_is_cintegrator())
> totalram_pages +=
free_area(__phys_to_pfn(__pa(__init_begin)),
> __phys_to_pfn(__pa(__init_end)),
> "init");
> +#endif
> }
>
> #ifdef CONFIG_BLK_DEV_INITRD
> diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
> index 8063a32..eee8f67 100644
> --- a/arch/arm/vfp/vfpmodule.c
> +++ b/arch/arm/vfp/vfpmodule.c
> @@ -364,7 +364,7 @@ void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs
> *regs)
> preempt_enable();
> }
>
> -static void vfp_enable(void *unused)
> +void vfp_enable(void *unused)
> {
> u32 access = get_copro_access();
>
> --
Thanks.
Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.
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