/* * 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