diff options
author | Len Brown <len.brown@intel.com> | 2009-01-09 03:39:43 -0500 |
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committer | Len Brown <len.brown@intel.com> | 2009-01-09 03:39:43 -0500 |
commit | b2576e1d4408e134e2188c967b1f28af39cd79d4 (patch) | |
tree | 004f3c82faab760f304ce031d6d2f572e7746a50 /arch/xtensa/include/asm/delay.h | |
parent | 3cc8a5f4ba91f67bbdb81a43a99281a26aab8d77 (diff) | |
parent | 2150edc6c5cf00f7adb54538b9ea2a3e9cedca3f (diff) |
Merge branch 'linus' into release
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 + |