[patch 4/6] [PREEMPT-RT] hwmon/coretemp: Convert to hotplug state machine

Thomas Gleixner
2016-11-22T17:45:35Z

[-- Attachment #1: hwmon-coretemp--Convert_to_hotplug_state_machine.patch --]
[-- Type: text/plain, Size: 5045 bytes --]

Install the callbacks via the state machine. Setup and teardown are handled
by the hotplug core.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-hwmon@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: rt@linuxtronix.de
Cc: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/20161117183541.8588-5-bigeasy@linutronix.de

---
drivers/hwmon/coretemp.c | 86 +++++++++++++++--------------------------------
1 file changed, 29 insertions(+), 57 deletions(-)

--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -649,7 +649,7 @@ static void coretemp_device_remove(unsig
mutex_unlock(&pdev_list_mutex);
}

-static void get_core_online(unsigned int cpu)
+static int coretemp_cpu_online(unsigned int cpu)
{
struct platform_device *pdev = coretemp_get_pdev(cpu);
struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -662,12 +662,12 @@ static void get_core_online(unsigned int
* without thermal sensors will be filtered out.
*/
if (!cpu_has(c, X86_FEATURE_DTHERM))
- return;
+ return 0;

if (!pdev) {
/* Check the microcode version of the CPU */
if (chk_ucode_version(cpu))
- return;
+ return 0;

/*
* Alright, we have DTS support.
@@ -677,7 +677,7 @@ static void get_core_online(unsigned int
*/
err = coretemp_device_add(cpu);
if (err)
- return;
+ return 0;

pdev = coretemp_get_pdev(cpu);
/*
@@ -697,9 +697,10 @@ static void get_core_online(unsigned int
coretemp_add_core(pdev, cpu, 0);

cpumask_set_cpu(cpu, &pdata->cpumask);
+ return 0;
}

-static void put_core_offline(unsigned int cpu)
+static int coretemp_cpu_offline(unsigned int cpu)
{
struct platform_device *pdev = coretemp_get_pdev(cpu);
struct platform_data *pd;
@@ -708,12 +709,12 @@ static void put_core_offline(unsigned in

/* If the physical CPU device does not exist, just return */
if (!pdev)
- return;
+ return 0;

/* The core id is too big, just return */
indx = TO_ATTR_NO(cpu);
if (indx > MAX_CORE_DATA - 1)
- return;
+ return 0;

pd = platform_get_drvdata(pdev);
tdata = pd->core_data[indx];
@@ -742,7 +743,7 @@ static void put_core_offline(unsigned in
*/
if (cpumask_empty(&pd->cpumask)) {
coretemp_device_remove(cpu);
- return;
+ return 0;
}
/*
* Check whether this core is the target for the package
@@ -755,38 +756,19 @@ static void put_core_offline(unsigned in
tdata->cpu = target;
mutex_unlock(&tdata->update_lock);
}
+ return 0;
}
-
-static int coretemp_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- unsigned int cpu = (unsigned long) hcpu;
-
- switch (action) {
- case CPU_ONLINE:
- case CPU_DOWN_FAILED:
- get_core_online(cpu);
- break;
- case CPU_DOWN_PREPARE:
- put_core_offline(cpu);
- break;
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block coretemp_cpu_notifier __refdata = {
- .notifier_call = coretemp_cpu_callback,
-};
-
static const struct x86_cpu_id __initconst coretemp_ids[] = {
{ X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_DTHERM },
{}
};
MODULE_DEVICE_TABLE(x86cpu, coretemp_ids);

+static enum cpuhp_state coretemp_hp_online;
+
static int __init coretemp_init(void)
{
- int i, err;
+ int err;

/*
* CPUID.06H.EAX[0] indicates whether the CPU has thermal
@@ -798,52 +780,42 @@ static int __init coretemp_init(void)

err = platform_driver_register(&coretemp_driver);
if (err)
- goto exit;
+ return err;

- cpu_notifier_register_begin();
- for_each_online_cpu(i)
- get_core_online(i);
+ get_online_cpus();
+ err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/coretemp:online",
+ coretemp_cpu_online, coretemp_cpu_offline);
+ if (err < 0)
+ goto exit_driver_unreg;
+ coretemp_hp_online = err;

#ifndef CONFIG_HOTPLUG_CPU
if (list_empty(&pdev_list)) {
- cpu_notifier_register_done();
err = -ENODEV;
- goto exit_driver_unreg;
+ goto exit_hp_unreg;
}
#endif
-
- __register_hotcpu_notifier(&coretemp_cpu_notifier);
- cpu_notifier_register_done();
+ put_online_cpus();
return 0;

#ifndef CONFIG_HOTPLUG_CPU
+exit_hp_unreg:
+ cpuhp_remove_state(coretemp_hp_online);
+ put_online_cpus();
+#endif
exit_driver_unreg:
platform_driver_unregister(&coretemp_driver);
-#endif
-exit:
return err;
}
+module_init(coretemp_init)

static void __exit coretemp_exit(void)
{
- struct pdev_entry *p, *n;
-
- cpu_notifier_register_begin();
- __unregister_hotcpu_notifier(&coretemp_cpu_notifier);
- mutex_lock(&pdev_list_mutex);
- list_for_each_entry_safe(p, n, &pdev_list, list) {
- platform_device_unregister(p->pdev);
- list_del(&p->list);
- kfree(p);
- }
- mutex_unlock(&pdev_list_mutex);
- cpu_notifier_register_done();
+ cpuhp_remove_state(coretemp_hp_online);
platform_driver_unregister(&coretemp_driver);
}
+module_exit(coretemp_exit)

MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
MODULE_DESCRIPTION("Intel Core temperature monitor");
MODULE_LICENSE("GPL");
-
-module_init(coretemp_init)
-module_exit(coretemp_exit)