linux/arch/sh/kernel/idle.c
Peter Zijlstra 58c644ba51 sched/idle: Fix arch_cpu_idle() vs tracing
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
2020-11-24 16:47:35 +01:00

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C

// SPDX-License-Identifier: GPL-2.0
/*
* The idle loop for all SuperH platforms.
*
* Copyright (C) 2002 - 2009 Paul Mundt
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/preempt.h>
#include <linux/thread_info.h>
#include <linux/irqflags.h>
#include <linux/smp.h>
#include <linux/atomic.h>
#include <asm/smp.h>
#include <asm/bl_bit.h>
static void (*sh_idle)(void);
void default_idle(void)
{
set_bl_bit();
raw_local_irq_enable();
/* Isn't this racy ? */
cpu_sleep();
clear_bl_bit();
}
void arch_cpu_idle_dead(void)
{
play_dead();
}
void arch_cpu_idle(void)
{
sh_idle();
}
void __init select_idle_routine(void)
{
/*
* If a platform has set its own idle routine, leave it alone.
*/
if (!sh_idle)
sh_idle = default_idle;
}
void stop_this_cpu(void *unused)
{
local_irq_disable();
set_cpu_online(smp_processor_id(), false);
for (;;)
cpu_sleep();
}