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

From: [email-masked] (Jisheng Zhang)
Date: Thu, 9 Jul 2015 14:35:52 +0800

Dear Lorenzo,

On Wed, 8 Jul 2015 18:34:58 +0100
Lorenzo Pieralisi <[email-masked]> 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 <[email-masked]>
> > ---
> >  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 <[email-masked]>
> > + *
> > + * 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
> >