Commit 8848f066 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Add cpuidle context save/restore helpers 



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, there is no functional
change.

Tested-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Reviewed-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210615111227.2454465-2-maz@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent c4681547

arch/arm/include/asm/cpuidle.h

+5 −0
Original line number Diff line number Diff line
@@ -49,4 +49,9 @@ extern int arm_cpuidle_suspend(int index); 


extern int arm_cpuidle_init(int cpu);



struct arm_cpuidle_irq_context { };



#define arm_cpuidle_save_irq_context(c)		(void)c

#define arm_cpuidle_restore_irq_context(c)	(void)c



#endif

arch/arm64/include/asm/cpuidle.h

+35 −0
Original line number Diff line number Diff line
@@ -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_irq_context {

	unsigned long pmr;

	unsigned long daif_bits;

};



#define arm_cpuidle_save_irq_context(__c)				\

	do {								\

		struct arm_cpuidle_irq_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_irq_context(__c)				\

	do {								\

		struct arm_cpuidle_irq_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_irq_context { };



#define arm_cpuidle_save_irq_context(c)		(void)c

#define arm_cpuidle_restore_irq_context(c)	(void)c

#endif

#endif