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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-i386/timex.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-i386/timex.h')
-rw-r--r--include/asm-i386/timex.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/include/asm-i386/timex.h b/include/asm-i386/timex.h
new file mode 100644
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+++ b/include/asm-i386/timex.h
@@ -0,0 +1,52 @@
1/*
2 * linux/include/asm-i386/timex.h
3 *
4 * i386 architecture timex specifications
5 */
6#ifndef _ASMi386_TIMEX_H
7#define _ASMi386_TIMEX_H
8
9#include <linux/config.h>
10#include <asm/processor.h>
11
12#ifdef CONFIG_X86_ELAN
13# define CLOCK_TICK_RATE 1189200 /* AMD Elan has different frequency! */
14#else
15# define CLOCK_TICK_RATE 1193182 /* Underlying HZ */
16#endif
17
18
19/*
20 * Standard way to access the cycle counter on i586+ CPUs.
21 * Currently only used on SMP.
22 *
23 * If you really have a SMP machine with i486 chips or older,
24 * compile for that, and this will just always return zero.
25 * That's ok, it just means that the nicer scheduling heuristics
26 * won't work for you.
27 *
28 * We only use the low 32 bits, and we'd simply better make sure
29 * that we reschedule before that wraps. Scheduling at least every
30 * four billion cycles just basically sounds like a good idea,
31 * regardless of how fast the machine is.
32 */
33typedef unsigned long long cycles_t;
34
35static inline cycles_t get_cycles (void)
36{
37 unsigned long long ret=0;
38
39#ifndef CONFIG_X86_TSC
40 if (!cpu_has_tsc)
41 return 0;
42#endif
43
44#if defined(CONFIG_X86_GENERIC) || defined(CONFIG_X86_TSC)
45 rdtscll(ret);
46#endif
47 return ret;
48}
49
50extern unsigned long cpu_khz;
51
52#endif