diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index fce22c4b2f7300ce2d22721abbfea3c14f3b9dfd..8b131bc8984d054706a43dbaf59f92792435c587 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)