arm64: Miscellaneous header files

This patch introduces a few AArch64-specific header files together with
Kbuild entries for generic headers.

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>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
new file mode 100644
index 0000000..d4a6333
--- /dev/null
+++ b/arch/arm64/include/asm/barrier.h
@@ -0,0 +1,52 @@
+/*
+ * Based on arch/arm/include/asm/barrier.h
+ *
+ * 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_BARRIER_H
+#define __ASM_BARRIER_H
+
+#ifndef __ASSEMBLY__
+
+#define sev()		asm volatile("sev" : : : "memory")
+#define wfe()		asm volatile("wfe" : : : "memory")
+#define wfi()		asm volatile("wfi" : : : "memory")
+
+#define isb()		asm volatile("isb" : : : "memory")
+#define dsb()		asm volatile("dsb sy" : : : "memory")
+
+#define mb()		dsb()
+#define rmb()		asm volatile("dsb ld" : : : "memory")
+#define wmb()		asm volatile("dsb st" : : : "memory")
+
+#ifndef CONFIG_SMP
+#define smp_mb()	barrier()
+#define smp_rmb()	barrier()
+#define smp_wmb()	barrier()
+#else
+#define smp_mb()	asm volatile("dmb ish" : : : "memory")
+#define smp_rmb()	asm volatile("dmb ishld" : : : "memory")
+#define smp_wmb()	asm volatile("dmb ishst" : : : "memory")
+#endif
+
+#define read_barrier_depends()		do { } while(0)
+#define smp_read_barrier_depends()	do { } while(0)
+
+#define set_mb(var, value)	do { var = value; smp_mb(); } while (0)
+#define nop()		asm volatile("nop");
+
+#endif	/* __ASSEMBLY__ */
+
+#endif	/* __ASM_BARRIER_H */