FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2024-12-27 03:47:43 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

x86, hotplug, suspend: Online CPU0 for suspend or hibernate

Browse Source 
Because x86 BIOS requires CPU0 to resume from sleep, suspend or hibernate can't
be executed if CPU0 is detected offline. To make suspend or hibernate and
further resume succeed, CPU0 must be online.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-6-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Fenghua Yu 2012-11-13 11:32:42 -08:00 committed by H. Peter Anvin
parent 30106c1743
commit 209efae129
1 changed files with 44 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
arch/x86/power/cpu.c
View File

@ -237,3 +237,47 @@ void restore_processor_state(void)
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(restore_processor_state);
#endif
/*
* When bsp_check() is called in hibernate and suspend, cpu hotplug
* is disabled already. So it's unnessary to handle race condition between
* cpumask query and cpu hotplug.
*/
static int bsp_check(void)
{
if (cpumask_first(cpu_online_mask) != 0) {
pr_warn("CPU0 is offline.\n");
return -ENODEV;
}
return 0;
}
static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
void *ptr)
{
int ret = 0;
switch (action) {
case PM_SUSPEND_PREPARE:
case PM_HIBERNATION_PREPARE:
ret = bsp_check();
break;
default:
break;
}
return notifier_from_errno(ret);
}
static int __init bsp_pm_check_init(void)
{
/*
* Set this bsp_pm_callback as lower priority than
* cpu_hotplug_pm_callback. So cpu_hotplug_pm_callback will be called
* earlier to disable cpu hotplug before bsp online check.
*/
pm_notifier(bsp_pm_callback, -INT_MAX);
return 0;
}
core_initcall(bsp_pm_check_init);