hotplug, powerpc, x86: Remove cpu_hotplug_driver_lock()
cpu_hotplug_driver_lock() serializes CPU online/offline operations
when ARCH_CPU_PROBE_RELEASE is set. This lock interface is no longer
necessary with the following reason:
- lock_device_hotplug() now protects CPU online/offline operations,
including the probe & release interfaces enabled by
ARCH_CPU_PROBE_RELEASE. The use of cpu_hotplug_driver_lock() is
redundant.
- cpu_hotplug_driver_lock() is only valid when ARCH_CPU_PROBE_RELEASE
is defined, which is misleading and is only enabled on powerpc.
This patch removes the cpu_hotplug_driver_lock() interface. As
a result, ARCH_CPU_PROBE_RELEASE only enables / disables the cpu
probe & release interface as intended. There is no functional change
in this patch.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 51f5d7f..f48370d 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -44,13 +44,11 @@
struct cpu *cpu = container_of(dev, struct cpu, dev);
int cpuid = dev->id;
int from_nid, to_nid;
- int ret = -ENODEV;
-
- cpu_hotplug_driver_lock();
+ int ret;
from_nid = cpu_to_node(cpuid);
if (from_nid == NUMA_NO_NODE)
- goto out;
+ return -ENODEV;
ret = cpu_up(cpuid);
/*
@@ -61,19 +59,12 @@
if (from_nid != to_nid)
change_cpu_under_node(cpu, from_nid, to_nid);
- out:
- cpu_hotplug_driver_unlock();
return ret;
}
static int cpu_subsys_offline(struct device *dev)
{
- int ret;
-
- cpu_hotplug_driver_lock();
- ret = cpu_down(dev->id);
- cpu_hotplug_driver_unlock();
- return ret;
+ return cpu_down(dev->id);
}
void unregister_cpu(struct cpu *cpu)
