From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- include/asm-m68knommu/delay.h | 76 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 include/asm-m68knommu/delay.h (limited to 'include/asm-m68knommu/delay.h') diff --git a/include/asm-m68knommu/delay.h b/include/asm-m68knommu/delay.h new file mode 100644 index 00000000000..e3a97625467 --- /dev/null +++ b/include/asm-m68knommu/delay.h @@ -0,0 +1,76 @@ +#ifndef _M68KNOMMU_DELAY_H +#define _M68KNOMMU_DELAY_H + +/* + * Copyright (C) 1994 Hamish Macdonald + * Copyright (C) 2004 Greg Ungerer + */ + +#include + +extern __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 arbitary 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; + +extern __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 biger, so it makes + * sense to library it. + */ +extern void udelay(unsigned long usecs); + +#endif /* defined(_M68KNOMMU_DELAY_H) */ -- cgit v1.2.3