[PATCH 04/20] hwmon/coretemp: Convert to hotplug state machine

From: Sebastian Andrzej Siewior
Date: Thu Nov 17 2016 - 13:37:43 EST


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

Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Jean Delvare <jdelvare@xxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: linux-hwmon@xxxxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
drivers/hwmon/coretemp.c | 74 +++++++++++++++---------------------------------
1 file changed, 23 insertions(+), 51 deletions(-)

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 6a27eb2fed17..390038884f9e 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -676,7 +676,7 @@ static bool is_any_core_online(struct platform_data *pdata)
return false;
}

-static void get_core_online(unsigned int cpu)
+static int coretemp_cpu_online(unsigned int cpu)
{
struct cpuinfo_x86 *c = &cpu_data(cpu);
struct platform_device *pdev = coretemp_get_pdev(cpu);
@@ -688,12 +688,12 @@ static void get_core_online(unsigned int cpu)
* 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.
@@ -703,7 +703,7 @@ static void get_core_online(unsigned int cpu)
*/
err = coretemp_device_add(cpu);
if (err)
- return;
+ return 0;
/*
* Check whether pkgtemp support is available.
* If so, add interfaces for pkgtemp.
@@ -716,9 +716,10 @@ static void get_core_online(unsigned int cpu)
* So, just add interfaces for this core.
*/
coretemp_add_core(cpu, 0);
+ return 0;
}

-static void put_core_offline(unsigned int cpu)
+static int coretemp_cpu_offline(unsigned int cpu)
{
int i, indx;
struct platform_data *pdata;
@@ -726,7 +727,7 @@ static void put_core_offline(unsigned int cpu)

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

pdata = platform_get_drvdata(pdev);

@@ -734,7 +735,7 @@ static void put_core_offline(unsigned int cpu)

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

if (pdata->core_data[indx] && pdata->core_data[indx]->cpu == cpu)
coretemp_remove_core(pdata, indx);
@@ -747,7 +748,7 @@ static void put_core_offline(unsigned int cpu)
*/
for_each_sibling(i, cpu) {
if (i != cpu) {
- get_core_online(i);
+ coretemp_cpu_online(i);
/*
* Display temperature sensor data for one HT sibling
* per core only, so abort the loop after one such
@@ -764,38 +765,20 @@ static void put_core_offline(unsigned int cpu)
*/
if (!is_any_core_online(pdata))
coretemp_device_remove(cpu);
+ 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
@@ -809,44 +792,33 @@ static int __init coretemp_init(void)
if (err)
goto exit;

- cpu_notifier_register_begin();
- for_each_online_cpu(i)
- get_core_online(i);
+ 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();
return 0;

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

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);
}

--
2.10.2