2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1994 by Waldorf Electronics
7 * Copyright (C) 1995 - 1998, 2001 by Ralf Baechle
12 #include <linux/config.h>
13 #include <linux/param.h>
15 #include <asm/compiler.h>
17 extern unsigned long loops_per_jiffy;
19 static __inline__ void __delay(unsigned long loops)
21 __asm__ __volatile__ (
31 * Division by multiplication: you don't have to worry about
34 * Use only for very small delays ( < 1 msec). Should probably use a
35 * lookup table, really, as the multiplications take much too long with
36 * short delays. This is a "reasonable" implementation, though (and the
37 * first constant multiplications gets optimized away if the delay is
40 static __inline__ void __udelay(unsigned long usecs, unsigned long lpj)
45 * Excessive precission? Probably ...
47 usecs *= (unsigned long) (((0x8000000000000000ULL / (500000 / HZ)) +
48 0x80000000ULL) >> 32);
49 __asm__("multu\t%2,%3"
50 : "=h" (usecs), "=l" (lo)
51 : "r" (usecs), "r" (lpj)
56 static __inline__ void __ndelay(unsigned long nsecs, unsigned long lpj)
61 * Excessive precission? Probably ...
63 nsecs *= (unsigned long) (((0x8000000000000000ULL / (500000000 / HZ)) +
64 0x80000000ULL) >> 32);
65 __asm__("multu\t%2,%3"
66 : "=h" (nsecs), "=l" (lo)
67 : "r" (nsecs), "r" (lpj)
73 #define __udelay_val cpu_data[smp_processor_id()].udelay_val
75 #define __udelay_val loops_per_jiffy
78 #define udelay(usecs) __udelay((usecs),__udelay_val)
79 #define ndelay(nsecs) __ndelay((nsecs),__udelay_val)
81 #endif /* _ASM_DELAY_H */