[PATCH 1/3] arm64: Add cpuidle context save/restore helpers
Lorenzo Pieralisi
lorenzo.pieralisi at arm.com
Fri Jun 11 09:46:57 PDT 2021
On Tue, Jun 08, 2021 at 06:27:13PM +0100, Marc Zyngier wrote:
> As we need to start doing some additional work on all idle
> paths, let's introduce a set of macros that will perform
> the work related to the GICv3 pseudo-NMI idle entry exit.
>
> Stubs are introduced to 32bit ARM for compatibility.
> As these helpers are currently unused, the is no functional
s/the/there
> change.
>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
> arch/arm/include/asm/cpuidle.h | 5 +++++
> arch/arm64/include/asm/cpuidle.h | 35 ++++++++++++++++++++++++++++++++
> 2 files changed, 40 insertions(+)
>
> diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h
> index 0d67ed682e07..1e0b8da12d96 100644
> --- a/arch/arm/include/asm/cpuidle.h
> +++ b/arch/arm/include/asm/cpuidle.h
> @@ -49,4 +49,9 @@ extern int arm_cpuidle_suspend(int index);
>
> extern int arm_cpuidle_init(int cpu);
>
> +struct arm_cpuidle_context { };
> +
> +#define arm_cpuidle_save_context(c) (void)c
> +#define arm_cpuidle_restore_context(c) (void)c
> +
> #endif
> diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h
> index 3c5ddb429ea2..53adad0a5c7e 100644
> --- a/arch/arm64/include/asm/cpuidle.h
> +++ b/arch/arm64/include/asm/cpuidle.h
> @@ -18,4 +18,39 @@ static inline int arm_cpuidle_suspend(int index)
> return -EOPNOTSUPP;
> }
> #endif
> +
> +#ifdef CONFIG_ARM64_PSEUDO_NMI
> +#include <asm/arch_gicv3.h>
> +
> +struct arm_cpuidle_context {
> + unsigned long pmr;
> + unsigned long daif_bits;
> +};
> +
> +#define arm_cpuidle_save_context(__c) \
> + do { \
> + struct arm_cpuidle_context *c = __c; \
> + if (system_uses_irq_prio_masking()) { \
> + c->daif_bits = read_sysreg(daif); \
> + write_sysreg(c->daif_bits | PSR_I_BIT | PSR_F_BIT, \
> + daif); \
> + c->pmr = gic_read_pmr(); \
> + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); \
> + } \
> + } while (0)
> +
> +#define arm_cpuidle_restore_context(__c) \
> + do { \
> + struct arm_cpuidle_context *c = __c; \
> + if (system_uses_irq_prio_masking()) { \
> + gic_write_pmr(c->pmr); \
> + write_sysreg(c->daif_bits, daif); \
> + } \
> + } while (0)
> +#else
> +struct arm_cpuidle_context { };
> +
> +#define arm_cpuidle_save_context(c) (void)c
> +#define arm_cpuidle_restore_context(c) (void)c
> +#endif
> #endif
It looks good to me - maybe I would define it irq_context for clarity
but that's just a naming convention.
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
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