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/* -*- c++ -*- */
/*
* Copyright 2007 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef INCLUDED_MEMORY_BARRIER_H
#define INCLUDED_MEMORY_BARRIER_H
/*
* powerpc memory barriers
*
* 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).
*
* smp_mb() prevents loads and stores being reordered across this point.
* smp_rmb() prevents loads being reordered across this point.
* smp_wmb() prevents stores being reordered across this point.
*
* We have to use the sync instructions for smp_mb(), since lwsync
* doesn't order loads with respect to previous stores. Lwsync is
* fine for smp_rmb(), though. For smp_wmb(), we use eieio since it
* is only used to order updates to system memory.
*
* For details, see "PowerPC Virtual Environment Architecture, Book
* II". Especially Chapter 1, "Storage Model" and Chapter 3, "Storage
* Control Instructions." (site:ibm.com)
*/
#include <ppu_intrinsics.h>
static inline void smp_mb(void)
{
__sync();
}
static inline void smp_rmb(void)
{
__lwsync();
}
static inline void smp_wmb(void)
{
__eieio();
}
#endif /* INCLUDED_MEMORY_BARRIER_H */
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