ACPI processor hotplug: Split up acpi_processor_add

No functional change.

This is needed because:
When a CPU gets hotplugged, it's totally uninitialized
and offline. cpuinfo_x86 struct (cpu_data(cpu)) is mostly
zero (CPU feature flags, model, family,..).

When a CPU gets hotplugged, struct processor is alloc'd,
some sysfs files are set up but acpi_processor_add()
must not try to access a MSR on this CPU or try to read
out CPU feature,family, etc.

This must be done in acpi_processor_start().
The next patch will delay the call of acpi_processor_start()
for physically hotpluggedcores, to the time when they are onlined
the first time. There it is safe then to access cpu_data(cpu)
cpuinfo_x86 struct or access MSRs which is needed to
set up cpuidle, throttling and other features.

Tested and
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 54 insertions, 38 deletions

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 0034ede38710..bec55937cf10 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -440,6 +440,58 @@ static struct notifier_block acpi_cpu_notifier =
             .notifier_call = acpi_cpu_soft_notify,
 };
 
+static int __cpuinit acpi_processor_start(struct acpi_processor *pr)
+{
+        struct acpi_device *device = per_cpu(processor_device_array, pr->id);
+        int result = 0;
+
+#ifdef CONFIG_CPU_FREQ
+        acpi_processor_ppc_has_changed(pr, 0);
+#endif
+        acpi_processor_get_throttling_info(pr);
+        acpi_processor_get_limit_info(pr);
+
+        if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
+                acpi_processor_power_init(pr, device);
+
+        pr->cdev = thermal_cooling_device_register("Processor", device,
+                                                   &processor_cooling_ops);
+        if (IS_ERR(pr->cdev)) {
+                result = PTR_ERR(pr->cdev);
+                goto err_power_exit;
+        }
+
+        dev_dbg(&device->dev, "registered as cooling_device%d\n",
+                pr->cdev->id);
+
+        result = sysfs_create_link(&device->dev.kobj,
+                                   &pr->cdev->device.kobj,
+                                   "thermal_cooling");
+        if (result) {
+                printk(KERN_ERR PREFIX "Create sysfs link\n");
+                goto err_thermal_unregister;
+        }
+        result = sysfs_create_link(&pr->cdev->device.kobj,
+                                   &device->dev.kobj,
+                                   "device");
+        if (result) {
+                printk(KERN_ERR PREFIX "Create sysfs link\n");
+                goto err_remove_sysfs_thermal;
+        }
+
+        return 0;
+
+err_remove_sysfs_thermal:
+        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
+err_thermal_unregister:
+        thermal_cooling_device_unregister(pr->cdev);
+err_power_exit:
+        acpi_processor_power_exit(pr, device);
+
+        return result;
+}
+
+
 static int __cpuinit acpi_processor_add(struct acpi_device *device)
 {
         struct acpi_processor *pr = NULL;
@@ -494,49 +546,13 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device)
                 result = -EFAULT;
                 goto err_free_cpumask;
         }
-
-#ifdef CONFIG_CPU_FREQ
-        acpi_processor_ppc_has_changed(pr, 0);
-#endif
-        acpi_processor_get_throttling_info(pr);
-        acpi_processor_get_limit_info(pr);
-
-        if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
-                acpi_processor_power_init(pr, device);
-
-        pr->cdev = thermal_cooling_device_register("Processor", device,
-                                                &processor_cooling_ops);
-        if (IS_ERR(pr->cdev)) {
-                result = PTR_ERR(pr->cdev);
-                goto err_power_exit;
-        }
-
-        dev_dbg(&device->dev, "registered as cooling_device%d\n",
-                 pr->cdev->id);
-
-        result = sysfs_create_link(&device->dev.kobj,
-                                   &pr->cdev->device.kobj,
-                                   "thermal_cooling");
-        if (result) {
-                printk(KERN_ERR PREFIX "Create sysfs link\n");
-                goto err_thermal_unregister;
-        }
-        result = sysfs_create_link(&pr->cdev->device.kobj,
-                                   &device->dev.kobj,
-                                   "device");
-        if (result) {
-                printk(KERN_ERR PREFIX "Create sysfs link\n");
+        result = acpi_processor_start(pr);
+        if (result)
                 goto err_remove_sysfs;
-        }
 
         return 0;
 
 err_remove_sysfs:
-        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
-err_thermal_unregister:
-        thermal_cooling_device_unregister(pr->cdev);
-err_power_exit:
-        acpi_processor_power_exit(pr, device);
         sysfs_remove_link(&device->dev.kobj, "sysdev");
 err_free_cpumask:
         free_cpumask_var(pr->throttling.shared_cpu_map);