HelenOS sources

root/kernel/arch/ppc32/include/arch/cycle.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. get_cycle

/*
 * Copyright (c) 2006 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup kernel_ppc32
 * @{
 */
/** @file
 */

#ifndef KERN_ppc32_CYCLE_H_
#define KERN_ppc32_CYCLE_H_

#include <trace.h>

_NO_TRACE static inline uint64_t get_cycle(void)
{
        uint32_t lower;
        uint32_t upper;
        uint32_t tmp;

        do {
                asm volatile (
                    "mftbu %[upper]\n"
                    "mftb %[lower]\n"
                    "mftbu %[tmp]\n"
                    : [upper] "=r" (upper),
                      [lower] "=r" (lower),
                      [tmp] "=r" (tmp)
                );
        } while (upper != tmp);

        return ((uint64_t) upper << 32) + (uint64_t) lower;
}

#endif

/** @}
 */

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