30 lines
1.1 KiB
C
30 lines
1.1 KiB
C
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/*
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* Copied from the kernel sources:
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*
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* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
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*/
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#ifndef _TOOLS_LINUX_ASM_POWERPC_BARRIER_H
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#define _TOOLS_LINUX_ASM_POWERPC_BARRIER_H
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/*
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* Memory barrier.
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* The sync instruction guarantees that all memory accesses initiated
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* by this processor have been performed (with respect to all other
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* mechanisms that access memory). The eieio instruction is a barrier
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* providing an ordering (separately) for (a) cacheable stores and (b)
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* loads and stores to non-cacheable memory (e.g. I/O devices).
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*
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* mb() prevents loads and stores being reordered across this point.
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* rmb() prevents loads being reordered across this point.
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* wmb() prevents stores being reordered across this point.
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*
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* *mb() variants without smp_ prefix must order all types of memory
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* operations with one another. sync is the only instruction sufficient
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* to do this.
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*/
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#define mb() __asm__ __volatile__ ("sync" : : : "memory")
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#define rmb() __asm__ __volatile__ ("sync" : : : "memory")
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#define wmb() __asm__ __volatile__ ("sync" : : : "memory")
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#endif /* _TOOLS_LINUX_ASM_POWERPC_BARRIER_H */
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