2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-19 18:53:52 +08:00
linux-next/include/linux/delay.h
Andrew Morton 5cba6d22e3 ndelay(): switch to C function to avoid 64-bit division
We should be able to do ndelay(some_u64), but that can cause a call to
__divdi3() to be emitted because the ndelay() macros does a divide.

Fix it by switching to static inline which will force the u64 arg to be
treated as an unsigned long.  udelay() takes an unsigned long arg.

[bunk@kernel.org: reported m68k build breakage]
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Martin Michlmayr <tbm@cyrius.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:12 -08:00

54 lines
1.3 KiB
C

#ifndef _LINUX_DELAY_H
#define _LINUX_DELAY_H
/*
* Copyright (C) 1993 Linus Torvalds
*
* Delay routines, using a pre-computed "loops_per_jiffy" value.
*/
#include <linux/kernel.h>
extern unsigned long loops_per_jiffy;
#include <asm/delay.h>
/*
* Using udelay() for intervals greater than a few milliseconds can
* risk overflow for high loops_per_jiffy (high bogomips) machines. The
* mdelay() provides a wrapper to prevent this. For delays greater
* than MAX_UDELAY_MS milliseconds, the wrapper is used. Architecture
* specific values can be defined in asm-???/delay.h as an override.
* The 2nd mdelay() definition ensures GCC will optimize away the
* while loop for the common cases where n <= MAX_UDELAY_MS -- Paul G.
*/
#ifndef MAX_UDELAY_MS
#define MAX_UDELAY_MS 5
#endif
#ifndef mdelay
#define mdelay(n) (\
(__builtin_constant_p(n) && (n)<=MAX_UDELAY_MS) ? udelay((n)*1000) : \
({unsigned long __ms=(n); while (__ms--) udelay(1000);}))
#endif
#ifndef ndelay
static inline void ndelay(unsigned long x)
{
udelay(DIV_ROUND_UP(x, 1000));
}
#define ndelay(x) ndelay(x)
#endif
void calibrate_delay(void);
void msleep(unsigned int msecs);
unsigned long msleep_interruptible(unsigned int msecs);
static inline void ssleep(unsigned int seconds)
{
msleep(seconds * 1000);
}
#endif /* defined(_LINUX_DELAY_H) */