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[v8,07/26] arm64: ptrace: Provide definitions for PMR values

Message ID 1546956464-48825-8-git-send-email-julien.thierry@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: provide pseudo NMI with GICv3 | expand

Commit Message

Julien Thierry Jan. 8, 2019, 2:07 p.m. UTC
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 <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/ptrace.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Catalin Marinas Jan. 14, 2019, 4:12 p.m. UTC | #1
On Tue, Jan 08, 2019 at 02:07:25PM +0000, Julien Thierry wrote:
> 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 <julien.thierry@arm.com>
> Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index fce22c4..05cf913 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 interrupt is masked. A lower value of PMR
+ * means more IRQ priorities are masked.
+ *
+ * To mask priorities, 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)