[PATCH 8/10] cpuid: fix cpu hotplug error handling

Akinobu Mita
2007-07-16T14:09:14Z

Make cpuid_device_create() CPU_UP_PREPARE event handler
instead of CPU_ONLINE event handler.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

---
arch/i386/kernel/cpuid.c | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)

Index: 2.6-mm/arch/i386/kernel/cpuid.c
===================================================================
--- 2.6-mm.orig/arch/i386/kernel/cpuid.c
+++ 2.6-mm/arch/i386/kernel/cpuid.c
@@ -152,32 +152,38 @@ static const struct file_operations cpui
.open = cpuid_open,
};

-static int cpuid_device_create(int i)
+static int cpuid_device_create(int cpu)
{
- int err = 0;
struct device *dev;

- dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, i), "cpu%d",i);
- if (IS_ERR(dev))
- err = PTR_ERR(dev);
- return err;
+ dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu),
+ "cpu%d", cpu);
+ return IS_ERR(dev) ? PTR_ERR(dev) : 0;
+}
+
+static void cpuid_device_destroy(int cpu)
+{
+ device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
}

static int cpuid_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
+ int err = 0;

switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- cpuid_device_create(cpu);
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ err = cpuid_device_create(cpu);
break;
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
+ cpuid_device_destroy(cpu);
break;
}
- return NOTIFY_OK;
+ return err ? NOTIFY_BAD : NOTIFY_OK;
}

static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier =
@@ -214,7 +220,7 @@ static int __init cpuid_init(void)
out_class:
i = 0;
for_each_online_cpu(i) {
- device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, i));
+ cpuid_device_destroy(i);
}
class_destroy(cpuid_class);
out_chrdev:
@@ -228,7 +234,7 @@ static void __exit cpuid_exit(void)
int cpu = 0;

for_each_online_cpu(cpu)
- device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
+ cpuid_device_destroy(cpu);
class_destroy(cpuid_class);
unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);