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 - 2000, 01, 03 by Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
13 #include <linux/config.h>
14 #include <linux/param.h>
16 #include <asm/compiler.h>
18 extern unsigned long loops_per_jiffy
;
20 static inline void __delay(unsigned long loops
)
22 if (sizeof(long) == 4)
23 __asm__
__volatile__ (
30 else if (sizeof(long) == 8)
31 __asm__
__volatile__ (
42 * Division by multiplication: you don't have to worry about
45 * Use only for very small delays ( < 1 msec). Should probably use a
46 * lookup table, really, as the multiplications take much too long with
47 * short delays. This is a "reasonable" implementation, though (and the
48 * first constant multiplications gets optimized away if the delay is
52 static inline void __udelay(unsigned long usecs
, unsigned long lpj
)
57 * The common rates of 1000 and 128 are rounded wrongly by the
58 * catchall case for 64-bit. Excessive precission? Probably ...
60 #if defined(CONFIG_MIPS64) && (HZ == 128)
61 usecs
*= 0x0008637bd05af6c7UL
; /* 2**64 / (1000000 / HZ) */
62 #elif defined(CONFIG_MIPS64) && (HZ == 1000)
63 usecs
*= 0x004189374BC6A7f0UL
; /* 2**64 / (1000000 / HZ) */
64 #elif defined(CONFIG_MIPS64)
65 usecs
*= (0x8000000000000000UL
/ (500000 / HZ
));
66 #else /* 32-bit junk follows here */
67 usecs
*= (unsigned long) (((0x8000000000000000ULL
/ (500000 / HZ
)) +
68 0x80000000ULL
) >> 32);
71 if (sizeof(long) == 4)
72 __asm__("multu\t%2, %3"
73 : "=h" (usecs
), "=l" (lo
)
74 : "r" (usecs
), "r" (lpj
)
76 else if (sizeof(long) == 8)
77 __asm__("dmultu\t%2, %3"
78 : "=h" (usecs
), "=l" (lo
)
79 : "r" (usecs
), "r" (lpj
)
86 #define __udelay_val cpu_data[smp_processor_id()].udelay_val
88 #define __udelay_val loops_per_jiffy
91 #define udelay(usecs) __udelay((usecs),__udelay_val)
93 #endif /* _ASM_DELAY_H */
This page took 0.03346 seconds and 5 git commands to generate.