arm64: IRQ handling

This patch adds the support for IRQ handling. The actual interrupt
controller will be part of a separate patch (going into
drivers/irqchip/).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h
new file mode 100644
index 0000000..aa11943
--- /dev/null
+++ b/arch/arm64/include/asm/irqflags.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_IRQFLAGS_H
+#define __ASM_IRQFLAGS_H
+
+#ifdef __KERNEL__
+
+#include <asm/ptrace.h>
+
+/*
+ * CPU interrupt mask handling.
+ */
+static inline unsigned long arch_local_irq_save(void)
+{
+	unsigned long flags;
+	asm volatile(
+		"mrs	%0, daif		// arch_local_irq_save\n"
+		"msr	daifset, #2"
+		: "=r" (flags)
+		:
+		: "memory");
+	return flags;
+}
+
+static inline void arch_local_irq_enable(void)
+{
+	asm volatile(
+		"msr	daifclr, #2		// arch_local_irq_enable"
+		:
+		:
+		: "memory");
+}
+
+static inline void arch_local_irq_disable(void)
+{
+	asm volatile(
+		"msr	daifset, #2		// arch_local_irq_disable"
+		:
+		:
+		: "memory");
+}
+
+#define local_fiq_enable()	asm("msr	daifclr, #1" : : : "memory")
+#define local_fiq_disable()	asm("msr	daifset, #1" : : : "memory")
+
+/*
+ * Save the current interrupt enable state.
+ */
+static inline unsigned long arch_local_save_flags(void)
+{
+	unsigned long flags;
+	asm volatile(
+		"mrs	%0, daif		// arch_local_save_flags"
+		: "=r" (flags)
+		:
+		: "memory");
+	return flags;
+}
+
+/*
+ * restore saved IRQ state
+ */
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	asm volatile(
+		"msr	daif, %0		// arch_local_irq_restore"
+	:
+	: "r" (flags)
+	: "memory");
+}
+
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+	return flags & PSR_I_BIT;
+}
+
+#endif
+#endif