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authorJosh Triplett <josh@joshtriplett.org>2011-12-03 13:06:50 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-12-11 10:32:20 -0800
commit2987557f52b97f679f0c324d8f51b8d66e1f2084 (patch)
tree93264730d265ef1987e45a97989d75b7a966dbab /drivers/base
parent2d1dc9a600edf33321bcdc1c808b7957d8a3f3e1 (diff)
downloadlinux-2987557f52b97f679f0c324d8f51b8d66e1f2084.tar.bz2
driver-core/cpu: Expose hotpluggability to the rest of the kernel
When architectures register CPUs, they indicate whether the CPU allows hotplugging; notably, x86 and ARM don't allow hotplugging CPU 0. Userspace can easily query the hotpluggability of a CPU via sysfs; however, the kernel has no convenient way of accessing that property in an architecture-independent way. While the kernel can simply try it and see, some code needs to distinguish between "hotplug failed" and "hotplug has no hope of working on this CPU"; for example, rcutorture's CPU hotplug tests want to avoid drowning out real hotplug failures with expected failures. Expose this property via a new cpu_is_hotpluggable function, so that the rest of the kernel can access it in an architecture-independent way. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/cpu.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 251acea3d359..3991502b21e5 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -247,6 +247,13 @@ struct sys_device *get_cpu_sysdev(unsigned cpu)
}
EXPORT_SYMBOL_GPL(get_cpu_sysdev);
+bool cpu_is_hotpluggable(unsigned cpu)
+{
+ struct sys_device *dev = get_cpu_sysdev(cpu);
+ return dev && container_of(dev, struct cpu, sysdev)->hotpluggable;
+}
+EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
+
int __init cpu_dev_init(void)
{
int err;