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-rw-r--r--arch/powerpc/platforms/pseries/dlpar.c45
-rw-r--r--drivers/base/cpu.c2
-rw-r--r--include/linux/cpu.h13
3 files changed, 50 insertions, 10 deletions
diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index 642e1b2e5c4..fd2f0afeb4d 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -436,6 +436,18 @@ int dlpar_release_drc(u32 drc_index)
#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+static DEFINE_MUTEX(pseries_cpu_hotplug_mutex);
+
+void cpu_hotplug_driver_lock()
+{
+ mutex_lock(&pseries_cpu_hotplug_mutex);
+}
+
+void cpu_hotplug_driver_unlock()
+{
+ mutex_unlock(&pseries_cpu_hotplug_mutex);
+}
+
static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
{
struct device_node *dn;
@@ -443,13 +455,18 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
char *cpu_name;
int rc;
+ cpu_hotplug_driver_lock();
rc = strict_strtoul(buf, 0, &drc_index);
- if (rc)
- return -EINVAL;
+ if (rc) {
+ rc = -EINVAL;
+ goto out;
+ }
dn = dlpar_configure_connector(drc_index);
- if (!dn)
- return -EINVAL;
+ if (!dn) {
+ rc = -EINVAL;
+ goto out;
+ }
/* configure-connector reports cpus as living in the base
* directory of the device tree. CPUs actually live in the
@@ -459,7 +476,8 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
GFP_KERNEL);
if (!cpu_name) {
dlpar_free_cc_nodes(dn);
- return -ENOMEM;
+ rc = -ENOMEM;
+ goto out;
}
sprintf(cpu_name, "/cpus%s", dn->full_name);
@@ -469,7 +487,8 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
rc = dlpar_acquire_drc(drc_index);
if (rc) {
dlpar_free_cc_nodes(dn);
- return -EINVAL;
+ rc = -EINVAL;
+ goto out;
}
rc = dlpar_attach_node(dn);
@@ -479,6 +498,8 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
}
rc = online_node_cpus(dn);
+out:
+ cpu_hotplug_driver_unlock();
return rc ? rc : count;
}
@@ -499,26 +520,30 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count)
return -EINVAL;
}
+ cpu_hotplug_driver_lock();
rc = offline_node_cpus(dn);
if (rc) {
of_node_put(dn);
- return -EINVAL;
+ rc = -EINVAL;
+ goto out;
}
rc = dlpar_release_drc(*drc_index);
if (rc) {
of_node_put(dn);
- return -EINVAL;
+ goto out;
}
rc = dlpar_detach_node(dn);
if (rc) {
dlpar_acquire_drc(*drc_index);
- return rc;
+ goto out;
}
of_node_put(dn);
- return count;
+out:
+ cpu_hotplug_driver_unlock();
+ return rc ? rc : count;
}
static int __init pseries_dlpar_init(void)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 7c03af7b84a..27fd775375b 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -35,6 +35,7 @@ static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribut
struct cpu *cpu = container_of(dev, struct cpu, sysdev);
ssize_t ret;
+ cpu_hotplug_driver_lock();
switch (buf[0]) {
case '0':
ret = cpu_down(cpu->sysdev.id);
@@ -49,6 +50,7 @@ static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribut
default:
ret = -EINVAL;
}
+ cpu_hotplug_driver_unlock();
if (ret >= 0)
ret = count;
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index c972f7ccb7d..e287863ac05 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -117,6 +117,19 @@ extern void put_online_cpus(void);
#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
int cpu_down(unsigned int cpu);
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+extern void cpu_hotplug_driver_lock(void);
+extern void cpu_hotplug_driver_unlock(void);
+#else
+static inline void cpu_hotplug_driver_lock(void)
+{
+}
+
+static inline void cpu_hotplug_driver_unlock(void)
+{
+}
+#endif
+
#else /* CONFIG_HOTPLUG_CPU */
#define get_online_cpus() do { } while (0)