kernel_optimize_test/arch/sh/lib/delay.c
Stuart Menefy bd4fb4d4c1 sh: Fix underflow in SH udelay() code.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-24 18:18:50 +09:00

44 lines
741 B
C

/*
* Precise Delay Loops for SuperH
*
* Copyright (C) 1999 Niibe Yutaka & Kaz Kojima
*/
#include <linux/sched.h>
#include <linux/delay.h>
void __delay(unsigned long loops)
{
__asm__ __volatile__(
"tst %0, %0\n\t"
"1:\t"
"bf/s 1b\n\t"
" dt %0"
: "=r" (loops)
: "0" (loops)
: "t");
}
inline void __const_udelay(unsigned long xloops)
{
xloops *= 4;
__asm__("dmulu.l %0, %2\n\t"
"sts mach, %0"
: "=r" (xloops)
: "0" (xloops),
"r" (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (HZ/4))
: "macl", "mach");
__delay(++xloops);
}
void __udelay(unsigned long usecs)
{
__const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */
}
void __ndelay(unsigned long nsecs)
{
__const_udelay(nsecs * 0x00000005);
}