diff options
Diffstat (limited to 'arch/i386/lib/delay.c')
| -rw-r--r-- | arch/i386/lib/delay.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/i386/lib/delay.c b/arch/i386/lib/delay.c new file mode 100644 index 00000000000..080639f262b --- /dev/null +++ b/arch/i386/lib/delay.c @@ -0,0 +1,49 @@ +/* + * Precise Delay Loops for i386 + * + * Copyright (C) 1993 Linus Torvalds + * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> + * + * The __delay function must _NOT_ be inlined as its execution time + * depends wildly on alignment on many x86 processors. The additional + * jump magic is needed to get the timing stable on all the CPU's + * we have to worry about. + */ + +#include <linux/config.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <asm/processor.h> +#include <asm/delay.h> +#include <asm/timer.h> + +#ifdef CONFIG_SMP +#include <asm/smp.h> +#endif + +extern struct timer_opts* timer; + +void __delay(unsigned long loops) +{ + cur_timer->delay(loops); +} + +inline void __const_udelay(unsigned long xloops) +{ + int d0; + xloops *= 4; + __asm__("mull %0" + :"=d" (xloops), "=&a" (d0) + :"1" (xloops),"0" (cpu_data[_smp_processor_id()].loops_per_jiffy * (HZ/4))); + __delay(++xloops); +} + +void __udelay(unsigned long usecs) +{ + __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ +} + +void __ndelay(unsigned long nsecs) +{ + __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ +} |