diff options
Diffstat (limited to 'arch/m68k')
| -rw-r--r-- | arch/m68k/include/asm/delay.h | 97 | ||||
| -rw-r--r-- | arch/m68k/include/asm/delay_mm.h | 57 | ||||
| -rw-r--r-- | arch/m68k/include/asm/delay_no.h | 76 | ||||
| -rw-r--r-- | arch/m68k/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/m68k/lib/delay.c | 21 |
5 files changed, 95 insertions, 158 deletions
diff --git a/arch/m68k/include/asm/delay.h b/arch/m68k/include/asm/delay.h index d2598e3..9c09bec 100644 --- a/arch/m68k/include/asm/delay.h +++ b/arch/m68k/include/asm/delay.h @@ -1,5 +1,96 @@ -#ifdef __uClinux__ -#include "delay_no.h" +#ifndef _M68K_DELAY_H +#define _M68K_DELAY_H + +#include <asm/param.h> + +/* + * Copyright (C) 1994 Hamish Macdonald + * Copyright (C) 2004 Greg Ungerer <gerg@uclinux.com> + * + * Delay routines, using a pre-computed "loops_per_jiffy" value. + */ + +#if defined(CONFIG_COLDFIRE) +/* + * The ColdFire runs the delay loop at significantly different speeds + * depending upon long word alignment or not. We'll pad it to + * long word alignment which is the faster version. + * The 0x4a8e is of course a 'tstl %fp' instruction. This is better + * than using a NOP (0x4e71) instruction because it executes in one + * cycle not three and doesn't allow for an arbitrary delay waiting + * for bus cycles to finish. Also fp/a6 isn't likely to cause a + * stall waiting for the register to become valid if such is added + * to the coldfire at some stage. + */ +#define DELAY_ALIGN ".balignw 4, 0x4a8e\n\t" #else -#include "delay_mm.h" +/* + * No instruction alignment required for other m68k types. + */ +#define DELAY_ALIGN #endif + +static inline void __delay(unsigned long loops) +{ + __asm__ __volatile__ ( + DELAY_ALIGN + "1: subql #1,%0\n\t" + "jcc 1b" + : "=d" (loops) + : "0" (loops)); +} + +extern void __bad_udelay(void); + + +#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE) +/* + * The simpler m68k and ColdFire processors do not have a 32*32->64 + * multiply instruction. So we need to handle them a little differently. + * We use a bit of shifting and a single 32*32->32 multiply to get close. + * This is a macro so that the const version can factor out the first + * multiply and shift. + */ +#define HZSCALE (268435456 / (1000000 / HZ)) + +#define __const_udelay(u) \ + __delay(((((u) * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6) + +#else + +static inline void __xdelay(unsigned long xloops) +{ + unsigned long tmp; + + __asm__ ("mulul %2,%0:%1" + : "=d" (xloops), "=d" (tmp) + : "d" (xloops), "1" (loops_per_jiffy)); + __delay(xloops * HZ); +} + +/* + * The definition of __const_udelay is specifically made a macro so that + * the const factor (4295 = 2**32 / 1000000) can be optimized out when + * the delay is a const. + */ +#define __const_udelay(n) (__xdelay((n) * 4295)) + +#endif + +static inline void __udelay(unsigned long usecs) +{ + __const_udelay(usecs); +} + +/* + * Use only for very small delays ( < 1 msec). Should probably use a + * lookup table, really, as the multiplications take much too long with + * short delays. This is a "reasonable" implementation, though (and the + * first constant multiplications gets optimized away if the delay is + * a constant) + */ +#define udelay(n) (__builtin_constant_p(n) ? \ + ((n) > 20000 ? __bad_udelay() : __const_udelay(n)) : __udelay(n)) + + +#endif /* defined(_M68K_DELAY_H) */ diff --git a/arch/m68k/include/asm/delay_mm.h b/arch/m68k/include/asm/delay_mm.h deleted file mode 100644 index 5ed9285..0000000 --- a/arch/m68k/include/asm/delay_mm.h +++ /dev/null @@ -1,57 +0,0 @@ -#ifndef _M68K_DELAY_H -#define _M68K_DELAY_H - -#include <asm/param.h> - -/* - * Copyright (C) 1994 Hamish Macdonald - * - * Delay routines, using a pre-computed "loops_per_jiffy" value. - */ - -static inline void __delay(unsigned long loops) -{ - __asm__ __volatile__ ("1: subql #1,%0; jcc 1b" - : "=d" (loops) : "0" (loops)); -} - -extern void __bad_udelay(void); - -/* - * Use only for very small delays ( < 1 msec). Should probably use a - * lookup table, really, as the multiplications take much too long with - * short delays. This is a "reasonable" implementation, though (and the - * first constant multiplications gets optimized away if the delay is - * a constant) - */ -static inline void __const_udelay(unsigned long xloops) -{ - unsigned long tmp; - - __asm__ ("mulul %2,%0:%1" - : "=d" (xloops), "=d" (tmp) - : "d" (xloops), "1" (loops_per_jiffy)); - __delay(xloops * HZ); -} - -static inline void __udelay(unsigned long usecs) -{ - __const_udelay(usecs * 4295); /* 2**32 / 1000000 */ -} - -#define udelay(n) (__builtin_constant_p(n) ? \ - ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 4295)) : \ - __udelay(n)) - -static inline unsigned long muldiv(unsigned long a, unsigned long b, - unsigned long c) -{ - unsigned long tmp; - - __asm__ ("mulul %2,%0:%1; divul %3,%0:%1" - : "=d" (tmp), "=d" (a) - : "d" (b), "d" (c), "1" (a)); - return a; -} - -#endif /* defined(_M68K_DELAY_H) */ diff --git a/arch/m68k/include/asm/delay_no.h b/arch/m68k/include/asm/delay_no.h deleted file mode 100644 index c3a0edc..0000000 --- a/arch/m68k/include/asm/delay_no.h +++ /dev/null @@ -1,76 +0,0 @@ -#ifndef _M68KNOMMU_DELAY_H -#define _M68KNOMMU_DELAY_H - -/* - * Copyright (C) 1994 Hamish Macdonald - * Copyright (C) 2004 Greg Ungerer <gerg@snapgear.com> - */ - -#include <asm/param.h> - -static inline void __delay(unsigned long loops) -{ -#if defined(CONFIG_COLDFIRE) - /* The coldfire runs this loop at significantly different speeds - * depending upon long word alignment or not. We'll pad it to - * long word alignment which is the faster version. - * The 0x4a8e is of course a 'tstl %fp' instruction. This is better - * than using a NOP (0x4e71) instruction because it executes in one - * cycle not three and doesn't allow for an arbitrary delay waiting - * for bus cycles to finish. Also fp/a6 isn't likely to cause a - * stall waiting for the register to become valid if such is added - * to the coldfire at some stage. - */ - __asm__ __volatile__ ( ".balignw 4, 0x4a8e\n\t" - "1: subql #1, %0\n\t" - "jcc 1b" - : "=d" (loops) : "0" (loops)); -#else - __asm__ __volatile__ ( "1: subql #1, %0\n\t" - "jcc 1b" - : "=d" (loops) : "0" (loops)); -#endif -} - -/* - * Ideally we use a 32*32->64 multiply to calculate the number of - * loop iterations, but the older standard 68k and ColdFire do not - * have this instruction. So for them we have a clsoe approximation - * loop using 32*32->32 multiplies only. This calculation based on - * the ARM version of delay. - * - * We want to implement: - * - * loops = (usecs * 0x10c6 * HZ * loops_per_jiffy) / 2^32 - */ - -#define HZSCALE (268435456 / (1000000/HZ)) - -extern unsigned long loops_per_jiffy; - -static inline void _udelay(unsigned long usecs) -{ -#if defined(CONFIG_M68328) || defined(CONFIG_M68EZ328) || \ - defined(CONFIG_M68VZ328) || defined(CONFIG_M68360) || \ - defined(CONFIG_COLDFIRE) - __delay((((usecs * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6); -#else - unsigned long tmp; - - usecs *= 4295; /* 2**32 / 1000000 */ - __asm__ ("mulul %2,%0:%1" - : "=d" (usecs), "=d" (tmp) - : "d" (usecs), "1" (loops_per_jiffy*HZ)); - __delay(usecs); -#endif -} - -/* - * Moved the udelay() function into library code, no longer inlined. - * I had to change the algorithm because we are overflowing now on - * the faster ColdFire parts. The code is a little bigger, so it makes - * sense to library it. - */ -extern void udelay(unsigned long usecs); - -#endif /* defined(_M68KNOMMU_DELAY_H) */ diff --git a/arch/m68k/lib/Makefile b/arch/m68k/lib/Makefile index df421e5..1a1bd90 100644 --- a/arch/m68k/lib/Makefile +++ b/arch/m68k/lib/Makefile @@ -9,6 +9,6 @@ lib-y := ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \ ifdef CONFIG_MMU lib-y += string.o uaccess.o checksum_mm.o else -lib-y += mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o delay.o checksum_no.o +lib-y += mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o checksum_no.o endif diff --git a/arch/m68k/lib/delay.c b/arch/m68k/lib/delay.c deleted file mode 100644 index 5bd5472..0000000 --- a/arch/m68k/lib/delay.c +++ /dev/null @@ -1,21 +0,0 @@ -/* - * arch/m68knommu/lib/delay.c - * - * (C) Copyright 2004, Greg Ungerer <gerg@snapgear.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <linux/module.h> -#include <asm/param.h> -#include <asm/delay.h> - -EXPORT_SYMBOL(udelay); - -void udelay(unsigned long usecs) -{ - _udelay(usecs); -} - |
