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	We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.
Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.
(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
		
	
			
		
			
				
	
	
		
			57 lines
		
	
	
	
		
			963 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			57 lines
		
	
	
	
		
			963 B
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * The idle loop for all SuperH platforms.
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 *
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 *  Copyright (C) 2002 - 2009  Paul Mundt
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 */
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/pm.h>
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#include <linux/tick.h>
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#include <linux/preempt.h>
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#include <linux/thread_info.h>
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#include <linux/irqflags.h>
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#include <linux/smp.h>
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#include <linux/atomic.h>
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#include <asm/smp.h>
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#include <asm/bl_bit.h>
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static void (*sh_idle)(void);
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void default_idle(void)
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{
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	set_bl_bit();
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	raw_local_irq_enable();
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	/* Isn't this racy ? */
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	cpu_sleep();
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	clear_bl_bit();
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}
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void arch_cpu_idle_dead(void)
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{
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	play_dead();
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}
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void arch_cpu_idle(void)
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{
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	sh_idle();
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}
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void __init select_idle_routine(void)
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{
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	/*
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	 * If a platform has set its own idle routine, leave it alone.
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	 */
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	if (!sh_idle)
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		sh_idle = default_idle;
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}
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void stop_this_cpu(void *unused)
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{
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	local_irq_disable();
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	set_cpu_online(smp_processor_id(), false);
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	for (;;)
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		cpu_sleep();
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}
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