[PATCH 19/22] ARM: CPU hotplug: move cpu_killed completion to core code
Vincent Guittot
vincent.guittot at linaro.org
Tue Dec 7 02:53:58 EST 2010
On 3 December 2010 21:37, <linux-arm-kernel-request at lists.infradead.org> wrote:
> Date: Fri, 03 Dec 2010 20:25:22 +0000
> From: Russell King - ARM Linux <linux at arm.linux.org.uk>
> To: linux-arm-kernel at lists.infradead.org, Catalin Marinas
> <catalin.marinas at arm.com>
> Subject: [PATCH 19/22] ARM: CPU hotplug: move cpu_killed completion to
> core code
> Message-ID: <E1POcC2-0007sD-I3 at rmk-PC.arm.linux.org.uk>
> Content-Type: text/plain; charset="us-ascii"
>
> We always need to wait for the dying CPU to reach a safe state before
> taking it down, irrespective of the requirements of the platform.
> Move the completion code into the ARM SMP hotplug code rather than
> having each platform re-implement this.
>
> Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> ---
> arch/arm/kernel/smp.c | 14 +++++++++++++-
> arch/arm/mach-omap2/omap-hotplug.c | 8 ++------
> arch/arm/mach-realview/hotplug.c | 8 +-------
> arch/arm/mach-s5pv310/hotplug.c | 8 +-------
> arch/arm/mach-tegra/hotplug.c | 8 +-------
> arch/arm/mach-ux500/hotplug.c | 8 +-------
> 6 files changed, 19 insertions(+), 35 deletions(-)
>
> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> index 1f1de2b..bebe3bd 100644
> --- a/arch/arm/kernel/smp.c
> +++ b/arch/arm/kernel/smp.c
> @@ -24,6 +24,7 @@
> #include <linux/irq.h>
> #include <linux/percpu.h>
> #include <linux/clockchips.h>
> +#include <linux/completion.h>
>
> #include <asm/atomic.h>
> #include <asm/cacheflush.h>
> @@ -238,12 +239,20 @@ int __cpu_disable(void)
> return 0;
> }
>
> +static DECLARE_COMPLETION(cpu_died);
> +
> /*
> * called on the thread which is asking for a CPU to be shutdown -
> * waits until shutdown has completed, or it is timed out.
> */
> void __cpu_die(unsigned int cpu)
> {
> + if (wait_for_completion_timeout(&cpu_died, 5000)) {
Shouldn't you test the opposite like with platform_cpu_kill below ?
> + printk(KERN_ERR "CPU%u: cpu didn't die\n", cpu);
> + return;
> + }
> + printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
> +
> if (!platform_cpu_kill(cpu))
> printk("CPU%u: unable to kill\n", cpu);
> }
> @@ -263,9 +272,12 @@ void __ref cpu_die(void)
> local_irq_disable();
> idle_task_exit();
>
> + /* Tell __cpu_die() that this CPU is now safe to dispose of */
> + complete(&cpu_died);
> +
> /*
> * actual CPU shutdown procedure is at least platform (if not
> - * CPU) specific
> + * CPU) specific.
> */
> platform_cpu_die(cpu);
>
> diff --git a/arch/arm/mach-omap2/omap-hotplug.c b/arch/arm/mach-omap2/omap-hotplug.c
> index 6cee456..ace979d 100644
> --- a/arch/arm/mach-omap2/omap-hotplug.c
> +++ b/arch/arm/mach-omap2/omap-hotplug.c
> @@ -17,16 +17,13 @@
> #include <linux/kernel.h>
> #include <linux/errno.h>
> #include <linux/smp.h>
> -#include <linux/completion.h>
>
> #include <asm/cacheflush.h>
> #include <mach/omap4-common.h>
>
> -static DECLARE_COMPLETION(cpu_killed);
> -
> int platform_cpu_kill(unsigned int cpu)
> {
> - return wait_for_completion_timeout(&cpu_killed, 5000);
> + return 1;
> }
>
> /*
> @@ -42,8 +39,7 @@ void platform_cpu_die(unsigned int cpu)
> this_cpu, cpu);
> BUG();
> }
> - pr_notice("CPU%u: shutdown\n", cpu);
> - complete(&cpu_killed);
> +
> flush_cache_all();
> dsb();
>
> diff --git a/arch/arm/mach-realview/hotplug.c b/arch/arm/mach-realview/hotplug.c
> index f95521a..7d58c16 100644
> --- a/arch/arm/mach-realview/hotplug.c
> +++ b/arch/arm/mach-realview/hotplug.c
> @@ -11,14 +11,11 @@
> #include <linux/kernel.h>
> #include <linux/errno.h>
> #include <linux/smp.h>
> -#include <linux/completion.h>
>
> #include <asm/cacheflush.h>
>
> extern volatile int pen_release;
>
> -static DECLARE_COMPLETION(cpu_killed);
> -
> static inline void cpu_enter_lowpower(void)
> {
> unsigned int v;
> @@ -95,7 +92,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
>
> int platform_cpu_kill(unsigned int cpu)
> {
> - return wait_for_completion_timeout(&cpu_killed, 5000);
> + return 1;
> }
>
> /*
> @@ -115,9 +112,6 @@ void platform_cpu_die(unsigned int cpu)
> }
> #endif
>
> - printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
> - complete(&cpu_killed);
> -
> /*
> * we're ready for shutdown now, so do it
> */
> diff --git a/arch/arm/mach-s5pv310/hotplug.c b/arch/arm/mach-s5pv310/hotplug.c
> index 03652c3..d7be70a 100644
> --- a/arch/arm/mach-s5pv310/hotplug.c
> +++ b/arch/arm/mach-s5pv310/hotplug.c
> @@ -13,14 +13,11 @@
> #include <linux/kernel.h>
> #include <linux/errno.h>
> #include <linux/smp.h>
> -#include <linux/completion.h>
>
> #include <asm/cacheflush.h>
>
> extern volatile int pen_release;
>
> -static DECLARE_COMPLETION(cpu_killed);
> -
> static inline void cpu_enter_lowpower(void)
> {
> unsigned int v;
> @@ -98,7 +95,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
>
> int platform_cpu_kill(unsigned int cpu)
> {
> - return wait_for_completion_timeout(&cpu_killed, 5000);
> + return 1;
> }
>
> /*
> @@ -118,9 +115,6 @@ void platform_cpu_die(unsigned int cpu)
> }
> #endif
>
> - printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
> - complete(&cpu_killed);
> -
> /*
> * we're ready for shutdown now, so do it
> */
> diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c
> index 8e7f115..ecaa41c 100644
> --- a/arch/arm/mach-tegra/hotplug.c
> +++ b/arch/arm/mach-tegra/hotplug.c
> @@ -11,12 +11,9 @@
> #include <linux/kernel.h>
> #include <linux/errno.h>
> #include <linux/smp.h>
> -#include <linux/completion.h>
>
> #include <asm/cacheflush.h>
>
> -static DECLARE_COMPLETION(cpu_killed);
> -
> static inline void cpu_enter_lowpower(void)
> {
> unsigned int v;
> @@ -94,7 +91,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
>
> int platform_cpu_kill(unsigned int cpu)
> {
> - return wait_for_completion_timeout(&cpu_killed, 5000);
> + return 1;
> }
>
> /*
> @@ -114,9 +111,6 @@ void platform_cpu_die(unsigned int cpu)
> }
> #endif
>
> - printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
> - complete(&cpu_killed);
> -
> /*
> * we're ready for shutdown now, so do it
> */
> diff --git a/arch/arm/mach-ux500/hotplug.c b/arch/arm/mach-ux500/hotplug.c
> index b782a03..7a4890b 100644
> --- a/arch/arm/mach-ux500/hotplug.c
> +++ b/arch/arm/mach-ux500/hotplug.c
> @@ -11,14 +11,11 @@
> #include <linux/kernel.h>
> #include <linux/errno.h>
> #include <linux/smp.h>
> -#include <linux/completion.h>
>
> #include <asm/cacheflush.h>
>
> extern volatile int pen_release;
>
> -static DECLARE_COMPLETION(cpu_killed);
> -
> static inline void platform_do_lowpower(unsigned int cpu)
> {
> flush_cache_all();
> @@ -38,7 +35,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
>
> int platform_cpu_kill(unsigned int cpu)
> {
> - return wait_for_completion_timeout(&cpu_killed, 5000);
> + return 1;
> }
>
> /*
> @@ -58,9 +55,6 @@ void platform_cpu_die(unsigned int cpu)
> }
> #endif
>
> - printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
> - complete(&cpu_killed);
> -
> /* directly enter low power state, skipping secure registers */
> platform_do_lowpower(cpu);
> }
> --
> 1.6.2.5
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