https://github.com/torvalds/linux
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Tip revision: 0173a3265b228da319ceb9c1ec6a5682fd1b2d92 authored by Linus Torvalds on 26 October 2008, 19:13:29 UTC
Linux 2.6.28-rc2
Tip revision: 0173a32
system.h
/*
 *  arch/arm/mach-ebsa110/include/mach/system.h
 *
 *  Copyright (C) 1996-2000 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef __ASM_ARCH_SYSTEM_H
#define __ASM_ARCH_SYSTEM_H

/*
 * EBSA110 idling methodology:
 *
 * We can not execute the "wait for interrupt" instruction since that
 * will stop our MCLK signal (which provides the clock for the glue
 * logic, and therefore the timer interrupt).
 *
 * Instead, we spin, polling the IRQ_STAT register for the occurrence
 * of any interrupt with core clock down to the memory clock.
 */
static inline void arch_idle(void)
{
	const char *irq_stat = (char *)0xff000000;

	/* disable clock switching */
	asm volatile ("mcr p15, 0, ip, c15, c2, 2" : : : "cc");

	/* wait for an interrupt to occur */
	while (!*irq_stat);

	/* enable clock switching */
	asm volatile ("mcr p15, 0, ip, c15, c1, 2" : : : "cc");
}

#define arch_reset(mode)	cpu_reset(0x80000000)

#endif
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