From: sboyd@codeaurora•org (Stephen Boyd)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv4 4/6] arm64: add CPU_HOTPLUG infrastructure
Date: Fri, 11 Oct 2013 15:24:28 -0700 [thread overview]
Message-ID: <52587A9C.9070503@codeaurora.org> (raw)
In-Reply-To: <1381515846-1684-5-git-send-email-mark.rutland@arm.com>
On 10/11/13 11:24, Mark Rutland wrote:
> diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
> index 1720be6..f4a11a3 100644
> --- a/arch/arm64/include/asm/cpu_ops.h
> +++ b/arch/arm64/include/asm/cpu_ops.h
> @@ -34,6 +34,11 @@ struct device_node;
> * @cpu_boot: Boots a cpu into the kernel.
> * @cpu_postboot: Optionally, perform any post-boot cleanup or necesary
> * synchronisation. Called from the cpu being booted.
> + * @cpu_disable: Prepares a cpu to die. May fail for some mechanism-specific
> + * reason, which will cause the hot unplug to be aborted. Called
> + * from the cpu to be killed.
> + * @cpu_die: Makes the a leave the kernel. Must not fail. Called from the
Makes the cpu? Makes a cpu?
> + * cpu being killed.
> */
> struct cpu_operations {
> const char *name;
> @@ -41,6 +46,10 @@ struct cpu_operations {
> int (*cpu_prepare)(unsigned int);
> int (*cpu_boot)(unsigned int);
> void (*cpu_postboot)(void);
> +#ifdef CONFIG_HOTPLUG_CPU
> + int (*cpu_disable)(unsigned int cpu);
> + void (*cpu_die)(unsigned int cpu);
> +#endif
> };
>
> extern const struct cpu_operations *cpu_ops[NR_CPUS];
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index 6806bc4..888776e 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
[snip]
> +
> +/*
> + * Called from the idle thread for the CPU which has been shutdown.
> + *
> + * Note that we disable IRQs here, but do not re-enable them
> + * before returning to the caller. This is also the behaviour
> + * of the other hotplug-cpu capable cores, so presumably coming
> + * out of idle fixes this.
> + */
> +void __ref cpu_die(void)
__ref is unnecessary now that __cpuinit is gone. I see arm32 needs the
same treatment.
> +{
> + unsigned int cpu = smp_processor_id();
> +
> + idle_task_exit();
> +
> + local_irq_disable();
> + mb();
Can you please comment this mb().
> +
> + /* Tell __cpu_die() that this CPU is now safe to dispose of */
> + complete(&cpu_died);
> +
>
--
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next prev parent reply other threads:[~2013-10-11 22:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-11 18:24 [PATCHv4 0/6] arm64: initial CPU hotplug support Mark Rutland
2013-10-11 18:24 ` [PATCHv4 1/6] arm64: unify smp_psci.c and psci.c Mark Rutland
2013-10-11 18:24 ` [PATCHv4 2/6] arm64: reorganise smp_enable_ops Mark Rutland
2013-10-11 18:24 ` [PATCHv4 3/6] arm64: factor out spin-table boot method Mark Rutland
2013-10-11 18:24 ` [PATCHv4 4/6] arm64: add CPU_HOTPLUG infrastructure Mark Rutland
2013-10-11 22:24 ` Stephen Boyd [this message]
2013-10-14 13:20 ` Mark Rutland
2013-10-11 18:24 ` [PATCHv4 5/6] arm64: add PSCI CPU_OFF-based hotplug support Mark Rutland
2013-10-11 18:24 ` [PATCHv4 6/6] arm64: read enable-method for CPU0 Mark Rutland
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