diff options
Diffstat (limited to 'arch/mips/lib')
| -rw-r--r-- | arch/mips/lib/Makefile | 4 | ||||
| -rw-r--r-- | arch/mips/lib/delay.c | 56 |
2 files changed, 58 insertions, 2 deletions
diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile index c13c7ad2cdae..2adead5a8a37 100644 --- a/arch/mips/lib/Makefile +++ b/arch/mips/lib/Makefile @@ -2,8 +2,8 @@ # Makefile for MIPS-specific library files.. # -lib-y += csum_partial.o memcpy.o memcpy-inatomic.o memset.o strlen_user.o \ - strncpy_user.o strnlen_user.o uncached.o +lib-y += csum_partial.o delay.o memcpy.o memcpy-inatomic.o memset.o \ + strlen_user.o strncpy_user.o strnlen_user.o uncached.o obj-y += iomap.o obj-$(CONFIG_PCI) += iomap-pci.o diff --git a/arch/mips/lib/delay.c b/arch/mips/lib/delay.c new file mode 100644 index 000000000000..f69c6b569eb3 --- /dev/null +++ b/arch/mips/lib/delay.c @@ -0,0 +1,56 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1994 by Waldorf Electronics + * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + * Copyright (C) 2007 Maciej W. Rozycki + */ +#include <linux/module.h> +#include <linux/param.h> +#include <linux/smp.h> + +#include <asm/compiler.h> +#include <asm/war.h> + +inline void __delay(unsigned int loops) +{ + __asm__ __volatile__ ( + " .set noreorder \n" + " .align 3 \n" + "1: bnez %0, 1b \n" + " subu %0, 1 \n" + " .set reorder \n" + : "=r" (loops) + : "0" (loops)); +} +EXPORT_SYMBOL(__delay); + +/* + * Division by multiplication: you don't have to worry about + * loss of precision. + * + * 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) + */ + +void __udelay(unsigned long us) +{ + unsigned int lpj = current_cpu_data.udelay_val; + + __delay((us * 0x000010c7 * HZ * lpj) >> 32); +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long ns) +{ + unsigned int lpj = current_cpu_data.udelay_val; + + __delay((us * 0x00000005 * HZ * lpj) >> 32); +} +EXPORT_SYMBOL(__ndelay); |
