/usr/include/xenomai/asm-nios2/tsc.h is in libxenomai-dev 2.6.4+dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 | /*
* Copyright (C) 2009 Philippe Gerum <rpm@xenomai.org>.
*
* Xenomai is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License,
* or (at your option) any later version.
*
* Xenomai 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with Xenomai; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#ifndef _XENO_ASM_NIOS2_TSC_H
#define _XENO_ASM_NIOS2_TSC_H
#ifndef __KERNEL__
extern volatile void *xeno_nios2_hrclock;
static inline unsigned long long __xn_rdtsc(void)
{
volatile unsigned short *hrclock;
int64_t t0, t1;
hrclock = xeno_nios2_hrclock;
#define hrclock_wrsnap(reg, val) \
(*(hrclock + (12 + ((reg) * 2)))) = (val)
#define hrclock_rdsnap(reg) \
(int64_t)(*(hrclock + (12 + ((reg) * 2)))) << (reg * 16)
#define hrclock_peeksnap() \
({ \
int64_t __snap; \
__snap = hrclock_rdsnap(3) | hrclock_rdsnap(2) | \
hrclock_rdsnap(1) | hrclock_rdsnap(0); \
__snap; \
})
#define hrclock_getsnap() \
({ \
hrclock_wrsnap(0, 0); \
hrclock_peeksnap(); \
})
/*
* We compete with both the kernel and userland applications
* which may request a snapshot as well, but we don't have any
* simple mutual exclusion mechanism at hand to avoid
* races. In order to keep the overhead of reading the hrclock
* from userland low, we make sure to read two consecutive
* coherent snapshots. In case both readings do not match, we
* have to request a fresh snapshot anew, since it means that
* we have been preempted in the middle of the operation.
*/
do {
t0 = hrclock_getsnap(); /* Request snapshot and read it */
__asm__ __volatile__("": : :"memory");
t1 = hrclock_peeksnap(); /* Confirm first reading */
} while (t0 != t1);
#undef hrclock_getsnap
#undef hrclock_rdsnap
#undef hrclock_wrsnap
return ~t0;
}
#endif /* __KERNEL__ */
#endif /* _XENO_ASM_NIOS2_TSC_H */
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