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/* * 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/timex.h> #include <asm/param.h> extern unsigned long loops_per_jiffy; static inline void __delay(unsigned long loops) { if (__builtin_constant_p(loops) && loops < 2) __asm__ __volatile__ ("nop"); else if (loops >= 2) /* 2 cycles per loop. */ __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b" : "+r" (loops)); } /* Undefined function to get compile-time error */ void __bad_udelay(void); void __bad_ndelay(void); #define __MAX_UDELAY 30000 #define __MAX_NDELAY 30000 static inline void __udelay(unsigned long usecs) { unsigned long start = get_ccount(); unsigned long cycles = (usecs * (ccount_freq >> 15)) >> 5; /* Note: all variables are unsigned (can wrap around)! */ while (((unsigned long)get_ccount()) - start < cycles) cpu_relax(); } static inline void udelay(unsigned long usec) { if (__builtin_constant_p(usec) && usec >= __MAX_UDELAY) __bad_udelay(); else __udelay(usec); } static inline void __ndelay(unsigned long nsec) { /* * Inner shift makes sure multiplication doesn't overflow * for legitimate nsec values */ unsigned long cycles = (nsec * (ccount_freq >> 15)) >> 15; __delay(cycles); } #define ndelay(n) ndelay(n) static inline void ndelay(unsigned long nsec) { if (__builtin_constant_p(nsec) && nsec >= __MAX_NDELAY) __bad_ndelay(); else __ndelay(nsec); } #endif