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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 /arch/alpha/lib/udelay.c
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 'arch/alpha/lib/udelay.c')
-rw-r--r--arch/alpha/lib/udelay.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/alpha/lib/udelay.c b/arch/alpha/lib/udelay.c
new file mode 100644
index 000000000000..1c879bbce419
--- /dev/null
+++ b/arch/alpha/lib/udelay.c
@@ -0,0 +1,55 @@
1/*
2 * Copyright (C) 1993, 2000 Linus Torvalds
3 *
4 * Delay routines, using a pre-computed "loops_per_jiffy" value.
5 */
6
7#include <linux/config.h>
8#include <linux/module.h>
9#include <linux/sched.h> /* for udelay's use of smp_processor_id */
10#include <asm/param.h>
11#include <asm/smp.h>
12#include <linux/delay.h>
13
14/*
15 * Use only for very small delays (< 1 msec).
16 *
17 * The active part of our cycle counter is only 32-bits wide, and
18 * we're treating the difference between two marks as signed. On
19 * a 1GHz box, that's about 2 seconds.
20 */
21
22void
23__delay(int loops)
24{
25 int tmp;
26 __asm__ __volatile__(
27 " rpcc %0\n"
28 " addl %1,%0,%1\n"
29 "1: rpcc %0\n"
30 " subl %1,%0,%0\n"
31 " bgt %0,1b"
32 : "=&r" (tmp), "=r" (loops) : "1"(loops));
33}
34
35#ifdef CONFIG_SMP
36#define LPJ cpu_data[smp_processor_id()].loops_per_jiffy
37#else
38#define LPJ loops_per_jiffy
39#endif
40
41void
42udelay(unsigned long usecs)
43{
44 usecs *= (((unsigned long)HZ << 32) / 1000000) * LPJ;
45 __delay((long)usecs >> 32);
46}
47EXPORT_SYMBOL(udelay);
48
49void
50ndelay(unsigned long nsecs)
51{
52 nsecs *= (((unsigned long)HZ << 32) / 1000000000) * LPJ;
53 __delay((long)nsecs >> 32);
54}
55EXPORT_SYMBOL(ndelay);