/*
* Copyright (c) 2007 Michal Kebrt
* 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_arm32
* @{
*/
/** @file
* @brief Count of CPU cycles.
*/
#ifndef KERN_arm32_CYCLE_H_
#define KERN_arm32_CYCLE_H_
#include <trace.h>
#include <arch/cp15.h>
/** Return count of CPU cycles.
*
* No such instruction on ARM to get count of cycles.
*
* @return Count of CPU cycles.
*
*/
_NO_TRACE static inline uint64_t get_cycle(void)
{
#ifdef PROCESSOR_ARCH_armv7_a
if ((ID_PFR1_read() & ID_PFR1_GEN_TIMER_EXT_MASK) ==
ID_PFR1_GEN_TIMER_EXT) {
uint32_t low = 0, high = 0;
asm volatile (
"MRRC p15, 0, %[low], %[high], c14"
: [low] "=r" (low), [high] "=r" (high)
);
return ((uint64_t)high << 32) | low;
} else {
return (uint64_t)PMCCNTR_read() * 64;
}
#endif
return 0;
}
#endif
/** @}
*/