diff options
Diffstat (limited to 'arch/x86/um/delay.c')
| -rw-r--r-- | arch/x86/um/delay.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/x86/um/delay.c b/arch/x86/um/delay.c new file mode 100644 index 000000000..a8fb7ca48 --- /dev/null +++ b/arch/x86/um/delay.c @@ -0,0 +1,60 @@ +/* + * Copyright (C) 2011 Richard Weinberger <richrd@nod.at> + * Mostly copied from arch/x86/lib/delay.c + * + * 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/export.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <asm/param.h> + +void __delay(unsigned long loops) +{ + asm volatile( + "test %0,%0\n" + "jz 3f\n" + "jmp 1f\n" + + ".align 16\n" + "1: jmp 2f\n" + + ".align 16\n" + "2: dec %0\n" + " jnz 2b\n" + "3: dec %0\n" + + : /* we don't need output */ + : "a" (loops) + ); +} +EXPORT_SYMBOL(__delay); + +inline void __const_udelay(unsigned long xloops) +{ + int d0; + + xloops *= 4; + asm("mull %%edx" + : "=d" (xloops), "=&a" (d0) + : "1" (xloops), "0" + (loops_per_jiffy * (HZ/4))); + + __delay(++xloops); +} +EXPORT_SYMBOL(__const_udelay); + +void __udelay(unsigned long usecs) +{ + __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long nsecs) +{ + __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ +} +EXPORT_SYMBOL(__ndelay); |