From cdbc81ddef43c8fdcbd3a26e1a7530c70b629cfc Mon Sep 17 00:00:00 2001 From: Julien Thierry Date: Thu, 31 Jan 2019 14:58:45 +0000 Subject: [PATCH] arm64: ptrace: Provide definitions for PMR values Introduce fixed values for PMR that are going to be used to mask and unmask interrupts by priority. The current priority given to GIC interrupts is 0xa0, so clearing PMR's most significant bit is enough to mask interrupts. Signed-off-by: Julien Thierry Suggested-by: Daniel Thompson Acked-by: Catalin Marinas Acked-by: Marc Zyngier Cc: Oleg Nesterov Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/ptrace.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index fce22c4..8b131bc 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -25,6 +25,18 @@ #define CurrentEL_EL1 (1 << 2) #define CurrentEL_EL2 (2 << 2) +/* + * PMR values used to mask/unmask interrupts. + * + * GIC priority masking works as follows: if an IRQ's priority is a higher value + * than the value held in PMR, that IRQ is masked. Lowering the value of PMR + * means masking more IRQs (or at least that the same IRQs remain masked). + * + * To mask interrupts, we clear the most significant bit of PMR. + */ +#define GIC_PRIO_IRQON 0xf0 +#define GIC_PRIO_IRQOFF (GIC_PRIO_IRQON & ~0x80) + /* Additional SPSR bits not exposed in the UABI */ #define PSR_IL_BIT (1 << 20) -- 2.7.4