mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 08:14:15 +08:00
58c644ba51
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
129 lines
2.6 KiB
C
129 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Idle daemon for PowerPC. Idle daemon will handle any action
|
|
* that needs to be taken when the system becomes idle.
|
|
*
|
|
* Originally written by Cort Dougan (cort@cs.nmt.edu).
|
|
* Subsequent 32-bit hacking by Tom Rini, Armin Kuster,
|
|
* Paul Mackerras and others.
|
|
*
|
|
* iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
|
|
*
|
|
* Additional shared processor, SMT, and firmware support
|
|
* Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
|
|
*
|
|
* 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org>
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/tick.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/cputable.h>
|
|
#include <asm/time.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/runlatch.h>
|
|
#include <asm/smp.h>
|
|
|
|
|
|
unsigned long cpuidle_disable = IDLE_NO_OVERRIDE;
|
|
EXPORT_SYMBOL(cpuidle_disable);
|
|
|
|
static int __init powersave_off(char *arg)
|
|
{
|
|
ppc_md.power_save = NULL;
|
|
cpuidle_disable = IDLE_POWERSAVE_OFF;
|
|
return 0;
|
|
}
|
|
__setup("powersave=off", powersave_off);
|
|
|
|
void arch_cpu_idle(void)
|
|
{
|
|
ppc64_runlatch_off();
|
|
|
|
if (ppc_md.power_save) {
|
|
ppc_md.power_save();
|
|
/*
|
|
* Some power_save functions return with
|
|
* interrupts enabled, some don't.
|
|
*/
|
|
if (irqs_disabled())
|
|
raw_local_irq_enable();
|
|
} else {
|
|
raw_local_irq_enable();
|
|
/*
|
|
* Go into low thread priority and possibly
|
|
* low power mode.
|
|
*/
|
|
HMT_low();
|
|
HMT_very_low();
|
|
}
|
|
|
|
HMT_medium();
|
|
ppc64_runlatch_on();
|
|
}
|
|
|
|
int powersave_nap;
|
|
|
|
#ifdef CONFIG_PPC_970_NAP
|
|
void power4_idle(void)
|
|
{
|
|
if (!cpu_has_feature(CPU_FTR_CAN_NAP))
|
|
return;
|
|
|
|
if (!powersave_nap)
|
|
return;
|
|
|
|
if (!prep_irq_for_idle())
|
|
return;
|
|
|
|
if (cpu_has_feature(CPU_FTR_ALTIVEC))
|
|
asm volatile("DSSALL ; sync" ::: "memory");
|
|
|
|
power4_idle_nap();
|
|
|
|
/*
|
|
* power4_idle_nap returns with interrupts enabled (soft and hard).
|
|
* to our caller with interrupts enabled (soft and hard). Our caller
|
|
* can cope with either interrupts disabled or enabled upon return.
|
|
*/
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
/*
|
|
* Register the sysctl to set/clear powersave_nap.
|
|
*/
|
|
static struct ctl_table powersave_nap_ctl_table[] = {
|
|
{
|
|
.procname = "powersave-nap",
|
|
.data = &powersave_nap,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{}
|
|
};
|
|
static struct ctl_table powersave_nap_sysctl_root[] = {
|
|
{
|
|
.procname = "kernel",
|
|
.mode = 0555,
|
|
.child = powersave_nap_ctl_table,
|
|
},
|
|
{}
|
|
};
|
|
|
|
static int __init
|
|
register_powersave_nap_sysctl(void)
|
|
{
|
|
register_sysctl_table(powersave_nap_sysctl_root);
|
|
|
|
return 0;
|
|
}
|
|
__initcall(register_powersave_nap_sysctl);
|
|
#endif
|