/* * 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 /** @} */