Re: [PATCH v2 2/2] arm: kernel: implement cpuidle_ops with psci backend

From: Jisheng Zhang
Date: Thu Jul 09 2015 - 02:36:55 EST


Dear Lorenzo,

On Wed, 8 Jul 2015 18:34:58 +0100
Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> wrote:

> On Wed, Jul 08, 2015 at 01:51:08PM +0100, Jisheng Zhang wrote:
> > This patch implements cpuidle_ops using psci. After this patch, we can
> > use cpuidle-arm.c with psci backend for both arm and arm64.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
> > ---
> > arch/arm/kernel/Makefile | 1 +
> > arch/arm/kernel/psci_cpuidle.c | 29 +++++++++++++++++++++++++++++
> > 2 files changed, 30 insertions(+)
> > create mode 100644 arch/arm/kernel/psci_cpuidle.c
> >
> > diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> > index 3b995f5..96383d8 100644
> > --- a/arch/arm/kernel/Makefile
> > +++ b/arch/arm/kernel/Makefile
> > @@ -91,6 +91,7 @@ obj-$(CONFIG_ARM_VIRT_EXT) += hyp-stub.o
> > ifeq ($(CONFIG_ARM_PSCI),y)
> > obj-y += psci-call.o
> > obj-$(CONFIG_SMP) += psci_smp.o
> > +obj-$(CONFIG_CPU_IDLE) += psci_cpuidle.o
> > endif
> >
> > extra-y := $(head-y) vmlinux.lds
> > diff --git a/arch/arm/kernel/psci_cpuidle.c b/arch/arm/kernel/psci_cpuidle.c
> > new file mode 100644
> > index 0000000..ae85d97
> > --- /dev/null
> > +++ b/arch/arm/kernel/psci_cpuidle.c
> > @@ -0,0 +1,29 @@
> > +/*
> > + * Copyright (C) 2015 Marvell Technology Group Ltd.
> > + * Author: Jisheng Zhang <jszhang@xxxxxxxxxxx>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#include <linux/cpuidle.h>
> > +#include <linux/psci.h>
> > +
> > +#include <asm/cpuidle.h>
> > +
> > +static int psci_cpuidle_suspend(int cpu, unsigned long arg)
> > +{
> > + return cpu_psci_cpu_suspend(arg);
> > +}
> > +
> > +static int psci_cpuidle_init(struct device_node *node, int cpu)
> > +{
> > + return cpu_psci_cpu_init_idle(cpu);
> > +}
>
> It probably makes sense to change the prototypes now that there is
> just one cpuidle ops merged for arm, better now than later.

Good idea. I will do as you suggested.

Thanks a lot,
Jisheng

>
> I am not too fussed about leaving these shims, but I think this can
> save us some time in the future.
>
> Daniel what do you think ?
>
> Lorenzo
>
> > +
> > +static struct cpuidle_ops psci_cpuidle_ops __initdata = {
> > + .suspend = psci_cpuidle_suspend,
> > + .init = psci_cpuidle_init,
> > +};
> > +CPUIDLE_METHOD_OF_DECLARE(psci_cpuidle, "psci", &psci_cpuidle_ops);
> > --
> > 2.1.4
> >

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