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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
4 * for more details.
5 *
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.
Maciej W. Rozycki20d60d92007-10-23 12:43:11 +01009 * Copyright (C) 2007 Maciej W. Rozycki
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
11#ifndef _ASM_DELAY_H
12#define _ASM_DELAY_H
13
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/param.h>
Ralf Baechle88de09f2005-04-18 10:40:09 +000015#include <linux/smp.h>
Maciej W. Rozycki20d60d92007-10-23 12:43:11 +010016
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <asm/compiler.h>
Maciej W. Rozycki20d60d92007-10-23 12:43:11 +010018#include <asm/war.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
Linus Torvalds1da177e2005-04-16 15:20:36 -070020static inline void __delay(unsigned long loops)
21{
22 if (sizeof(long) == 4)
23 __asm__ __volatile__ (
Ralf Baechle5ee82352006-05-23 16:37:32 +010024 " .set noreorder \n"
25 " .align 3 \n"
26 "1: bnez %0, 1b \n"
27 " subu %0, 1 \n"
28 " .set reorder \n"
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 : "=r" (loops)
30 : "0" (loops));
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +010031 else if (sizeof(long) == 8 && !DADDI_WAR)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 __asm__ __volatile__ (
Ralf Baechle5ee82352006-05-23 16:37:32 +010033 " .set noreorder \n"
34 " .align 3 \n"
35 "1: bnez %0, 1b \n"
36 " dsubu %0, 1 \n"
37 " .set reorder \n"
38 : "=r" (loops)
39 : "0" (loops));
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +010040 else if (sizeof(long) == 8 && DADDI_WAR)
41 __asm__ __volatile__ (
42 " .set noreorder \n"
43 " .align 3 \n"
44 "1: bnez %0, 1b \n"
45 " dsubu %0, %2 \n"
46 " .set reorder \n"
47 : "=r" (loops)
48 : "0" (loops), "r" (1));
Linus Torvalds1da177e2005-04-16 15:20:36 -070049}
50
51
52/*
53 * Division by multiplication: you don't have to worry about
54 * loss of precision.
55 *
56 * Use only for very small delays ( < 1 msec). Should probably use a
57 * lookup table, really, as the multiplications take much too long with
58 * short delays. This is a "reasonable" implementation, though (and the
59 * first constant multiplications gets optimized away if the delay is
60 * a constant)
61 */
62
63static inline void __udelay(unsigned long usecs, unsigned long lpj)
64{
Maciej W. Rozycki20d60d92007-10-23 12:43:11 +010065 unsigned long hi, lo;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67 /*
Atsushi Nemotof12555d2005-11-30 13:33:26 +090068 * The rates of 128 is rounded wrongly by the catchall case
69 * for 64-bit. Excessive precission? Probably ...
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 */
Ralf Baechle875d43e2005-09-03 15:56:16 -070071#if defined(CONFIG_64BIT) && (HZ == 128)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 usecs *= 0x0008637bd05af6c7UL; /* 2**64 / (1000000 / HZ) */
Ralf Baechle875d43e2005-09-03 15:56:16 -070073#elif defined(CONFIG_64BIT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 usecs *= (0x8000000000000000UL / (500000 / HZ));
75#else /* 32-bit junk follows here */
76 usecs *= (unsigned long) (((0x8000000000000000ULL / (500000 / HZ)) +
77 0x80000000ULL) >> 32);
78#endif
79
80 if (sizeof(long) == 4)
81 __asm__("multu\t%2, %3"
82 : "=h" (usecs), "=l" (lo)
83 : "r" (usecs), "r" (lpj)
84 : GCC_REG_ACCUM);
Maciej W. Rozycki20d60d92007-10-23 12:43:11 +010085 else if (sizeof(long) == 8 && !R4000_WAR)
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 __asm__("dmultu\t%2, %3"
87 : "=h" (usecs), "=l" (lo)
88 : "r" (usecs), "r" (lpj)
89 : GCC_REG_ACCUM);
Maciej W. Rozycki20d60d92007-10-23 12:43:11 +010090 else if (sizeof(long) == 8 && R4000_WAR)
91 __asm__("dmultu\t%3, %4\n\tmfhi\t%0"
92 : "=r" (usecs), "=h" (hi), "=l" (lo)
93 : "r" (usecs), "r" (lpj)
94 : GCC_REG_ACCUM);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 __delay(usecs);
97}
98
Deepak Saxena83598f12007-03-19 16:49:45 -070099#define __udelay_val cpu_data[raw_smp_processor_id()].udelay_val
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Ralf Baechle21a151d2007-10-11 23:46:15 +0100101#define udelay(usecs) __udelay((usecs), __udelay_val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Atsushi Nemotoa0f08202005-11-05 02:02:54 +0900103/* make sure "usecs *= ..." in udelay do not overflow. */
104#if HZ >= 1000
105#define MAX_UDELAY_MS 1
106#elif HZ <= 200
107#define MAX_UDELAY_MS 5
108#else
109#define MAX_UDELAY_MS (1000 / HZ)
110#endif
111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112#endif /* _ASM_DELAY_H */