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1/*
2 * include/asm-xtensa/delay.h
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 2001 - 2005 Tensilica Inc.
9 *
10 */
11
12#ifndef _XTENSA_DELAY_H
13#define _XTENSA_DELAY_H
14
15#include <linux/config.h>
16#include <asm/processor.h>
17#include <asm/param.h>
18
19extern unsigned long loops_per_jiffy;
20
21static inline void __delay(unsigned long loops)
22{
23 /* 2 cycles per loop. */
24 __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b"
25 : "=r" (loops) : "0" (loops));
26}
27
28static __inline__ u32 xtensa_get_ccount(void)
29{
30 u32 ccount;
31 asm volatile ("rsr %0, 234; # CCOUNT\n" : "=r" (ccount));
32 return ccount;
33}
34
35/* For SMP/NUMA systems, change boot_cpu_data to something like
36 * local_cpu_data->... where local_cpu_data points to the current
37 * cpu. */
38
39static __inline__ void udelay (unsigned long usecs)
40{
41 unsigned long start = xtensa_get_ccount();
42 unsigned long cycles = usecs * (loops_per_jiffy / (1000000UL / HZ));
43
44 /* Note: all variables are unsigned (can wrap around)! */
45 while (((unsigned long)xtensa_get_ccount()) - start < cycles)
46 ;
47}
48
49#endif
50