source: mainline/kernel/arch/arm32/include/cycle.h@ 7a38962

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 7a38962 was 9043e7e0, checked in by Jan Vesely <jano.vesely@…>, 13 years ago

arm32: Count every 64th cycle.

The coutner is 32bit, at 600Mhz it overflows after 7m instead of 7s.

  • Property mode set to 100644
File size: 2.1 KB
Line 
1/*
2 * Copyright (c) 2007 Michal Kebrt
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup arm32
30 * @{
31 */
32/** @file
33 * @brief Count of CPU cycles.
34 */
35
36#ifndef KERN_arm32_CYCLE_H_
37#define KERN_arm32_CYCLE_H_
38
39#include <trace.h>
40#include <arch/cp15.h>
41
42/** Return count of CPU cycles.
43 *
44 * No such instruction on ARM to get count of cycles.
45 *
46 * @return Count of CPU cycles.
47 *
48 */
49NO_TRACE static inline uint64_t get_cycle(void)
50{
51#ifdef PROCESSOR_ARCH_armv7_a
52 if ((ID_PFR1_read() & ID_PFR1_GEN_TIMER_EXT_MASK) ==
53 ID_PFR1_GEN_TIMER_EXT) {
54 uint32_t low = 0, high = 0;
55 asm volatile( "MRRC p15, 0, %[low], %[high], c14": [low]"=r"(low), [high]"=r"(high));
56 return ((uint64_t)high << 32) | low;
57 } else {
58 return (uint64_t)PMCCNTR_read() * 64;
59 }
60#endif
61 return 0;
62}
63
64#endif
65
66/** @}
67 */
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