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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copied from the kernel sources:
+ *
+ * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
+ */
+#ifndef _TOOLS_LINUX_ASM_POWERPC_BARRIER_H
+#define _TOOLS_LINUX_ASM_POWERPC_BARRIER_H
+
+/*
+ * Memory barrier.
+ * The sync instruction guarantees that all memory accesses initiated
+ * by this processor have been performed (with respect to all other
+ * mechanisms that access memory). The eieio instruction is a barrier
+ * providing an ordering (separately) for (a) cacheable stores and (b)
+ * loads and stores to non-cacheable memory (e.g. I/O devices).
+ *
+ * mb() prevents loads and stores being reordered across this point.
+ * rmb() prevents loads being reordered across this point.
+ * wmb() prevents stores being reordered across this point.
+ *
+ * *mb() variants without smp_ prefix must order all types of memory
+ * operations with one another. sync is the only instruction sufficient
+ * to do this.
+ */
+#define mb() __asm__ __volatile__ ("sync" : : : "memory")
+#define rmb() __asm__ __volatile__ ("sync" : : : "memory")
+#define wmb() __asm__ __volatile__ ("sync" : : : "memory")
+
+#if defined(__powerpc64__)
+#define smp_lwsync() __asm__ __volatile__ ("lwsync" : : : "memory")
+
+#define smp_store_release(p, v) \
+do { \
+ smp_lwsync(); \
+ WRITE_ONCE(*p, v); \
+} while (0)
+
+#define smp_load_acquire(p) \
+({ \
+ typeof(*p) ___p1 = READ_ONCE(*p); \
+ smp_lwsync(); \
+ ___p1; \
+})
+#endif /* defined(__powerpc64__) */
+#endif /* _TOOLS_LINUX_ASM_POWERPC_BARRIER_H */