From 2987557f52b97f679f0c324d8f51b8d66e1f2084 Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Sat, 3 Dec 2011 13:06:50 -0800 Subject: 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 Signed-off-by: Paul E. McKenney --- drivers/base/cpu.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers') 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; -- cgit v1.2.3