Initial commit.

Signed-off-by: Anup Patel <anup.patel@wdc.com>

include/sbi/riscv_barrier.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __RISCV_BARRIER_H__
+#define __RISCV_BARRIER_H__
+
+#define RISCV_ACQUIRE_BARRIER		"\tfence r , rw\n"
+#define RISCV_RELEASE_BARRIER		"\tfence rw,  w\n"
+
+#define RISCV_FENCE(p, s) \
+	__asm__ __volatile__ ("fence " #p "," #s : : : "memory")
+
+/* Read & Write Memory barrier */
+#define mb()			RISCV_FENCE(iorw,iorw)
+
+/* Read Memory barrier */
+#define rmb()			RISCV_FENCE(ir,ir)
+
+/* Write Memory barrier */
+#define wmb()			RISCV_FENCE(ow,ow)
+
+/* SMP Read & Write Memory barrier */
+#define smp_mb()		RISCV_FENCE(rw,rw)
+
+/* SMP Read Memory barrier */
+#define smp_rmb()		RISCV_FENCE(r,r)
+
+/* SMP Write Memory barrier */
+#define smp_wmb()		RISCV_FENCE(w,w)
+
+/* CPU relax for busy loop */
+#define cpu_relax()		asm volatile ("" : : : "memory")
+
+#define __smp_store_release(p, v)				\
+do {								\
+	RISCV_FENCE(rw,w);					\
+	*(p) = (v);						\
+} while (0)
+
+#define __smp_load_acquire(p)					\
+({								\
+	typeof(*p) ___p1 = *(p);				\
+	RISCV_FENCE(r,rw);					\
+	___p1;							\
+})
+
+#endif