[PATCH 11/21] ACPI: processor: Convert to hotplug state machine

Sebastian Andrzej Siewior
2016-09-06T17:06:36Z

Install the callbacks via the state machine.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
drivers/acpi/processor_driver.c | 89 +++++++++++++++++++------------------
drivers/acpi/processor_throttling.c | 4 +-
include/acpi/processor.h | 4 +-
include/linux/cpuhotplug.h | 1 +
4 files changed, 51 insertions(+), 47 deletions(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 0553aeebb228..13e5ac415abf 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -110,55 +110,46 @@ static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)

static int __acpi_processor_start(struct acpi_device *device);

-static int acpi_cpu_soft_notify(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
+static int acpi_soft_cpu_online(unsigned int cpu)
{
- unsigned int cpu = (unsigned long)hcpu;
struct acpi_processor *pr = per_cpu(processors, cpu);
struct acpi_device *device;
- action &= ~CPU_TASKS_FROZEN;
-
- switch (action) {
- case CPU_ONLINE:
- case CPU_DEAD:
- break;
- default:
- return NOTIFY_DONE;
- }

if (!pr || acpi_bus_get_device(pr->handle, &device))
- return NOTIFY_DONE;
+ return 0;
+ /*
+ * CPU got physically hotplugged and onlined for the first time:
+ * Initialize missing things.
+ */
+ if (pr->flags.need_hotplug_init) {
+ int ret;

- if (action == CPU_ONLINE) {
- /*
- * CPU got physically hotplugged and onlined for the first time:
- * Initialize missing things.
- */
- if (pr->flags.need_hotplug_init) {
- int ret;
-
- pr_info("Will online and init hotplugged CPU: %d\n",
- pr->id);
- pr->flags.need_hotplug_init = 0;
- ret = __acpi_processor_start(device);
- WARN(ret, "Failed to start CPU: %d\n", pr->id);
- } else {
- /* Normal CPU soft online event. */
- acpi_processor_ppc_has_changed(pr, 0);
- acpi_processor_hotplug(pr);
- acpi_processor_reevaluate_tstate(pr, action);
- acpi_processor_tstate_has_changed(pr);
- }
- } else if (action == CPU_DEAD) {
- /* Invalidate flag.throttling after the CPU is offline. */
- acpi_processor_reevaluate_tstate(pr, action);
+ pr_info("Will online and init hotplugged CPU: %d\n",
+ pr->id);
+ pr->flags.need_hotplug_init = 0;
+ ret = __acpi_processor_start(device);
+ WARN(ret, "Failed to start CPU: %d\n", pr->id);
+ } else {
+ /* Normal CPU soft online event. */
+ acpi_processor_ppc_has_changed(pr, 0);
+ acpi_processor_hotplug(pr);
+ acpi_processor_reevaluate_tstate(pr, false);
+ acpi_processor_tstate_has_changed(pr);
}
- return NOTIFY_OK;
+ return 0;
}

-static struct notifier_block acpi_cpu_notifier = {
- .notifier_call = acpi_cpu_soft_notify,
-};
+static int acpi_soft_cpu_dead(unsigned int cpu)
+{
+ struct acpi_processor *pr = per_cpu(processors, cpu);
+ struct acpi_device *device;
+
+ if (!pr || acpi_bus_get_device(pr->handle, &device))
+ return 0;
+
+ acpi_processor_reevaluate_tstate(pr, true);
+ return 0;
+}

#ifdef CONFIG_ACPI_CPU_FREQ_PSS
static int acpi_pss_perf_init(struct acpi_processor *pr,
@@ -303,7 +294,7 @@ static int acpi_processor_stop(struct device *dev)
* This is needed for the powernow-k8 driver, that works even without
* ACPI, but needs symbols from this driver
*/
-
+static enum cpuhp_state hp_online;
static int __init acpi_processor_driver_init(void)
{
int result = 0;
@@ -315,11 +306,22 @@ static int __init acpi_processor_driver_init(void)
if (result < 0)
return result;

- register_hotcpu_notifier(&acpi_cpu_notifier);
+ result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+ "acpi/cpu-drv:online",
+ acpi_soft_cpu_online, NULL);
+ if (result < 0)
+ goto err;
+ hp_online = result;
+ cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
+ NULL, acpi_soft_cpu_dead);
+
acpi_thermal_cpufreq_init();
acpi_processor_ppc_init();
acpi_processor_throttling_init();
return 0;
+err:
+ driver_unregister(&acpi_processor_driver);
+ return result;
}

static void __exit acpi_processor_driver_exit(void)
@@ -329,7 +331,8 @@ static void __exit acpi_processor_driver_exit(void)

acpi_processor_ppc_exit();
acpi_thermal_cpufreq_exit();
- unregister_hotcpu_notifier(&acpi_cpu_notifier);
+ cpuhp_remove_state_nocalls(hp_online);
+ cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
driver_unregister(&acpi_processor_driver);
}

diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index c72e64893d03..d51ca1c05619 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -375,11 +375,11 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
* 3. TSD domain
*/
void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
- unsigned long action)
+ bool is_dead)
{
int result = 0;

- if (action == CPU_DEAD) {
+ if (is_dead) {
/* When one CPU is offline, the T-state throttling
* will be invalidated.
*/
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index bfe6b2e10f3a..f3db11c24654 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -359,7 +359,7 @@ extern int acpi_processor_set_throttling(struct acpi_processor *pr,
* onlined/offlined. In such case the flags.throttling will be updated.
*/
extern void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
- unsigned long action);
+ bool is_dead);
extern const struct file_operations acpi_processor_throttling_fops;
extern void acpi_processor_throttling_init(void);
#else
@@ -380,7 +380,7 @@ static inline int acpi_processor_set_throttling(struct acpi_processor *pr,
}

static inline void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
- unsigned long action) {}
+ bool is_dead) {}

static inline void acpi_processor_throttling_init(void) {}
#endif /* CONFIG_ACPI_CPU_FREQ_PSS */
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 73a4daf08c04..0c33668d1626 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -25,6 +25,7 @@ enum cpuhp_state {
CPUHP_IRQ_POLL_DEAD,
CPUHP_BLOCK_SOFTIRQ_DEAD,
CPUHP_VIRT_SCSI_DEAD,
+ CPUHP_ACPI_CPUDRV_DEAD,
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,
--
2.9.3