linux_dsm_epyc7002/include/linux/delay.h
Patrick Pannuto 22b8f15c2f timer: Added usleep[_range] timer
usleep[_range] are finer precision implementations of msleep
and are designed to be drop-in replacements for udelay where
a precise sleep / busy-wait is unnecessary. They also allow
an easy interface to specify slack when a precise (ish)
wakeup is unnecessary to help minimize wakeups

Signed-off-by: Patrick Pannuto <ppannuto@codeaurora.org>
Cc: akinobu.mita@gmail.com
Cc: sboyd@codeaurora.org
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <4C44CDD2.1070708@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-23 15:08:12 +02:00

61 lines
1.5 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
extern unsigned long lpj_fine;
void calibrate_delay(void);
void msleep(unsigned int msecs);
unsigned long msleep_interruptible(unsigned int msecs);
void usleep_range(unsigned long min, unsigned long max);
static inline void usleep(unsigned long usecs)
{
usleep_range(usecs, usecs);
}
static inline void ssleep(unsigned int seconds)
{
msleep(seconds * 1000);
}
#endif /* defined(_LINUX_DELAY_H) */