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Diffstat (limited to '')
-rw-r--r-- | arch/mips/lib/delay.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/mips/lib/delay.c b/arch/mips/lib/delay.c new file mode 100644 index 000000000..2e8dfc1d5 --- /dev/null +++ b/arch/mips/lib/delay.c @@ -0,0 +1,69 @@ +/* + * 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, 2014 Maciej W. Rozycki + */ +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/param.h> +#include <linux/smp.h> +#include <linux/stringify.h> + +#include <asm/asm.h> +#include <asm/compiler.h> +#include <asm/war.h> + +#ifndef CONFIG_CPU_DADDI_WORKAROUNDS +#define GCC_DADDI_IMM_ASM() "I" +#else +#define GCC_DADDI_IMM_ASM() "r" +#endif + +#ifndef CONFIG_HAVE_PLAT_DELAY + +void __delay(unsigned long loops) +{ + __asm__ __volatile__ ( + " .set noreorder \n" + " .align 3 \n" + "1: bnez %0, 1b \n" + " " __stringify(LONG_SUBU) " %0, %1 \n" + " .set reorder \n" + : "=r" (loops) + : GCC_DADDI_IMM_ASM() (1), "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 = raw_current_cpu_data.udelay_val; + + __delay((us * 0x000010c7ull * HZ * lpj) >> 32); +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long ns) +{ + unsigned int lpj = raw_current_cpu_data.udelay_val; + + __delay((ns * 0x00000005ull * HZ * lpj) >> 32); +} +EXPORT_SYMBOL(__ndelay); + +#endif |