diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-01-11 15:34:05 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-01-11 15:34:05 +0100 |
commit | d19b85db9d5c44a4c21dcb10d6fbadaa4425ab2a (patch) | |
tree | 250be7a5a29069f7d1f4524fa45ab0e988833025 /arch/xtensa/include/asm/delay.h | |
parent | 490dea45d00f01847ebebd007685d564aaf2cd98 (diff) | |
parent | c59765042f53a79a7a65585042ff463b69cb248c (diff) |
Merge commit 'v2.6.29-rc1' into timers/urgent
Diffstat (limited to 'arch/xtensa/include/asm/delay.h')
-rw-r--r-- | arch/xtensa/include/asm/delay.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/delay.h b/arch/xtensa/include/asm/delay.h new file mode 100644 index 00000000000..e1d8c9e010c --- /dev/null +++ b/arch/xtensa/include/asm/delay.h @@ -0,0 +1,49 @@ +/* + * include/asm-xtensa/delay.h + * + * 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) 2001 - 2005 Tensilica Inc. + * + */ + +#ifndef _XTENSA_DELAY_H +#define _XTENSA_DELAY_H + +#include <asm/processor.h> +#include <asm/param.h> + +extern unsigned long loops_per_jiffy; + +static inline void __delay(unsigned long loops) +{ + /* 2 cycles per loop. */ + __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b" + : "=r" (loops) : "0" (loops)); +} + +static __inline__ u32 xtensa_get_ccount(void) +{ + u32 ccount; + asm volatile ("rsr %0, 234; # CCOUNT\n" : "=r" (ccount)); + return ccount; +} + +/* For SMP/NUMA systems, change boot_cpu_data to something like + * local_cpu_data->... where local_cpu_data points to the current + * cpu. */ + +static __inline__ void udelay (unsigned long usecs) +{ + unsigned long start = xtensa_get_ccount(); + unsigned long cycles = usecs * (loops_per_jiffy / (1000000UL / HZ)); + + /* Note: all variables are unsigned (can wrap around)! */ + while (((unsigned long)xtensa_get_ccount()) - start < cycles) + ; +} + +#endif + |