/*

 * Copyright (c) 2012, 2014 SAP SE. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

// Included in orderAccess.hpp header file.

#ifndef PPC64

#error "OrderAccess currently only implemented for PPC64"

#endif

// Compiler version last used for testing: gcc 4.1.2

// Please update this information when this file changes

// Implementation of class OrderAccess.

//

// Machine barrier instructions:

//

// - sync            Two-way memory barrier, aka fence.

// - lwsync          orders  Store|Store,

//                            Load|Store,

//                            Load|Load,

//                   but not Store|Load

// - eieio           orders  Store|Store

// - isync           Invalidates speculatively executed instructions,

//                   but isync may complete before storage accesses

//                   associated with instructions preceding isync have

//                   been performed.

//

// Semantic barrier instructions:

// (as defined in orderAccess.hpp)

//

// - release         orders Store|Store,       (maps to lwsync)

//                           Load|Store

// - acquire         orders  Load|Store,       (maps to lwsync)

//                           Load|Load

// - fence           orders Store|Store,       (maps to sync)

//                           Load|Store,

//                           Load|Load,

//                          Store|Load

//

#define inlasm_sync()     __asm__ __volatile__ ("sync"   : : : "memory");

#define inlasm_lwsync()   __asm__ __volatile__ ("lwsync" : : : "memory");

#define inlasm_eieio()    __asm__ __volatile__ ("eieio"  : : : "memory");

#define inlasm_isync()    __asm__ __volatile__ ("isync"  : : : "memory");

// Use twi-isync for load_acquire (faster than lwsync).

#define inlasm_acquire_reg(X) __asm__ __volatile__ ("twi 0,%0,0\n isync\n" : : "r" (X) : "memory");

inline void   OrderAccess::loadload()   { inlasm_lwsync(); }

inline void   OrderAccess::storestore() { inlasm_lwsync(); }

inline void   OrderAccess::loadstore()  { inlasm_lwsync(); }

inline void   OrderAccess::storeload()  { inlasm_sync();   }

inline void   OrderAccess::acquire()    { inlasm_lwsync(); }

inline void   OrderAccess::release()    { inlasm_lwsync(); }

inline void   OrderAccess::fence()      { inlasm_sync();   }

template<size_t byte_size>

struct OrderAccess::PlatformOrderedLoad<byte_size, X_ACQUIRE>

{

  template <typename T>

  T operator()(const volatile T* p) const { T t = Atomic::load(p); inlasm_acquire_reg(t); return t; }

};

#undef inlasm_sync

#undef inlasm_lwsync

#undef inlasm_eieio

#undef inlasm_isync

#undef inlasm_acquire_reg