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! --- arch/x86_64/lib/delay.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 arch/x86_64/lib/delay.c (limited to 'arch/x86_64/lib/delay.c') diff --git a/arch/x86_64/lib/delay.c b/arch/x86_64/lib/delay.c new file mode 100644 index 00000000000..6e2d66472eb --- /dev/null +++ b/arch/x86_64/lib/delay.c @@ -0,0 +1,48 @@ +/* + * Precise Delay Loops for x86-64 + * + * Copyright (C) 1993 Linus Torvalds + * Copyright (C) 1997 Martin Mares + * + * The __delay function must _NOT_ be inlined as its execution time + * depends wildly on alignment on many x86 processors. + */ + +#include +#include +#include +#include + +#ifdef CONFIG_SMP +#include +#endif + +int x86_udelay_tsc = 0; /* Delay via TSC */ + +void __delay(unsigned long loops) +{ + unsigned bclock, now; + + rdtscl(bclock); + do + { + rep_nop(); + rdtscl(now); + } + while((now-bclock) < loops); +} + +inline void __const_udelay(unsigned long xloops) +{ + __delay(((xloops * cpu_data[_smp_processor_id()].loops_per_jiffy) >> 32) * HZ); +} + +void __udelay(unsigned long usecs) +{ + __const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */ +} + +void __ndelay(unsigned long nsecs) +{ + __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ +} -- cgit v1.2.3