1 files changed, 52 insertions, 0 deletions
diff --git a/include/linux/irqchip/arm-gic-v3-prio.h b/include/linux/irqchip/arm-gic-v3-prio.h
new file mode 100644
index 000000000000..44157c9abb78
--- /dev/null
+++ b/include/linux/irqchip/arm-gic-v3-prio.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __LINUX_IRQCHIP_ARM_GIC_V3_PRIO_H
+#define __LINUX_IRQCHIP_ARM_GIC_V3_PRIO_H
+
+/*
+ * GIC priorities from the view of the PMR/RPR.
+ *
+ * These values are chosen to be valid in either the absolute priority space or
+ * the NS view of the priority space. The value programmed into the distributor
+ * and ITS will be chosen at boot time such that these values appear in the
+ * PMR/RPR.
+ *
+ * GICV3_PRIO_UNMASKED is the PMR view of the priority to use to permit both
+ * IRQs and pseudo-NMIs.
+ *
+ * GICV3_PRIO_IRQ is the PMR view of the priority of regular interrupts. This
+ * can be written to the PMR to mask regular IRQs.
+ *
+ * GICV3_PRIO_NMI is the PMR view of the priority of pseudo-NMIs. This can be
+ * written to the PMR to mask pseudo-NMIs.
+ *
+ * On arm64 some code sections either automatically switch back to PSR.I or
+ * explicitly require to not use priority masking. If bit GICV3_PRIO_PSR_I_SET
+ * is included in the priority mask, it indicates that PSR.I should be set and
+ * interrupt disabling temporarily does not rely on IRQ priorities.
+ */
+#define GICV3_PRIO_UNMASKED	0xe0
+#define GICV3_PRIO_IRQ		0xc0
+#define GICV3_PRIO_NMI		0x80
+
+#define GICV3_PRIO_PSR_I_SET	(1 << 4)
+
+#ifndef __ASSEMBLER__
+
+#define __gicv3_prio_to_ns(p)	(0xff & ((p) << 1))
+#define __gicv3_ns_to_prio(ns)	(0x80 | ((ns) >> 1))
+
+#define __gicv3_prio_valid_ns(p) \
+	(__gicv3_ns_to_prio(__gicv3_prio_to_ns(p)) == (p))
+
+static_assert(__gicv3_prio_valid_ns(GICV3_PRIO_NMI));
+static_assert(__gicv3_prio_valid_ns(GICV3_PRIO_IRQ));
+
+static_assert(GICV3_PRIO_NMI < GICV3_PRIO_IRQ);
+static_assert(GICV3_PRIO_IRQ < GICV3_PRIO_UNMASKED);
+
+static_assert(GICV3_PRIO_IRQ < (GICV3_PRIO_IRQ | GICV3_PRIO_PSR_I_SET));
+
+#endif /* __ASSEMBLER */
+
+#endif /* __LINUX_IRQCHIP_ARM_GIC_V3_PRIO_H */