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| author | Ingo Molnar <mingo@elte.hu> | 2008-08-15 17:07:34 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-08-15 17:07:34 +0200 |
| commit | 04197c83b3e05546d1003cfa3ff43f1639c0057f (patch) | |
| tree | c04ddce9f519b91c0b20c6c09f7529928350eefe /arch/arm/include/asm/delay.h | |
| parent | 71998e83c520c7a91b254dc9705baeedbee0d44f (diff) | |
| parent | b635acec48bcaa9183fcbf4e3955616b0d4119b5 (diff) | |
| download | linux-04197c83b3e05546d1003cfa3ff43f1639c0057f.tar.gz linux-04197c83b3e05546d1003cfa3ff43f1639c0057f.tar.bz2 linux-04197c83b3e05546d1003cfa3ff43f1639c0057f.zip | |
Merge branch 'linus' into x86/tracehook
Conflicts:
arch/x86/Kconfig
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/arm/include/asm/delay.h')
| -rw-r--r-- | arch/arm/include/asm/delay.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/include/asm/delay.h b/arch/arm/include/asm/delay.h new file mode 100644 index 000000000000..b2deda181549 --- /dev/null +++ b/arch/arm/include/asm/delay.h @@ -0,0 +1,44 @@ +/* + * Copyright (C) 1995-2004 Russell King + * + * Delay routines, using a pre-computed "loops_per_second" value. + */ +#ifndef __ASM_ARM_DELAY_H +#define __ASM_ARM_DELAY_H + +#include <asm/param.h> /* HZ */ + +extern void __delay(int loops); + +/* + * This function intentionally does not exist; if you see references to + * it, it means that you're calling udelay() with an out of range value. + * + * With currently imposed limits, this means that we support a max delay + * of 2000us. Further limits: HZ<=1000 and bogomips<=3355 + */ +extern void __bad_udelay(void); + +/* + * division by multiplication: you don't have to worry about + * loss of precision. + * + * Use only for very small delays ( < 1 msec). Should probably use a + * lookup table, really, as the multiplications take much too long with + * short delays. This is a "reasonable" implementation, though (and the + * first constant multiplications gets optimized away if the delay is + * a constant) + */ +extern void __udelay(unsigned long usecs); +extern void __const_udelay(unsigned long); + +#define MAX_UDELAY_MS 2 + +#define udelay(n) \ + (__builtin_constant_p(n) ? \ + ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \ + __const_udelay((n) * ((2199023U*HZ)>>11))) : \ + __udelay(n)) + +#endif /* defined(_ARM_DELAY_H) */ + |
