Provide a special exported function for the device core to bring a cpu
up/down and hide the real cpu_up/down as they are treated as private
functions. cpu_up/down are lower level API and users outside the cpu
subsystem should use device_online/offline which will take care of extra
housekeeping work like keeping sysfs in sync.
Signed-off-by: Qais Yousef <[email protected]>
CC: Greg Kroah-Hartman <[email protected]>
CC: "Rafael J. Wysocki" <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Josh Poimboeuf <[email protected]>
CC: Nicholas Piggin <[email protected]>
CC: "Peter Zijlstra (Intel)" <[email protected]>
CC: Jiri Kosina <[email protected]>
CC: Daniel Lezcano <[email protected]>
CC: Eiichi Tsukata <[email protected]>
CC: Zhenzhong Duan <[email protected]>
CC: Ingo Molnar <[email protected]>
CC: Pavankumar Kondeti <[email protected]>
CC: [email protected]
---
drivers/base/cpu.c | 4 ++--
include/linux/cpu.h | 4 ++--
kernel/cpu.c | 26 ++++++++++++++++++++++----
3 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index cc37511de866..96c69c5fbfff 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -55,7 +55,7 @@ static int cpu_subsys_online(struct device *dev)
if (from_nid == NUMA_NO_NODE)
return -ENODEV;
- ret = cpu_up(cpuid);
+ ret = cpu_subsys_up(dev);
/*
* When hot adding memory to memoryless node and enabling a cpu
* on the node, node number of the cpu may internally change.
@@ -69,7 +69,7 @@ static int cpu_subsys_online(struct device *dev)
static int cpu_subsys_offline(struct device *dev)
{
- return cpu_down(dev->id);
+ return cpu_subsys_down(dev);
}
void unregister_cpu(struct cpu *cpu)
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index b1c7b788b8e9..6822e676f420 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -83,7 +83,7 @@ extern ssize_t arch_cpu_release(const char *, size_t);
#ifdef CONFIG_SMP
extern bool cpuhp_tasks_frozen;
-int cpu_up(unsigned int cpu);
+int cpu_subsys_up(struct device *dev);
void notify_cpu_starting(unsigned int cpu);
extern void cpu_maps_update_begin(void);
extern void cpu_maps_update_done(void);
@@ -114,7 +114,7 @@ extern void lockdep_assert_cpus_held(void);
extern void cpu_hotplug_disable(void);
extern void cpu_hotplug_enable(void);
void clear_tasks_mm_cpumask(int cpu);
-int cpu_down(unsigned int cpu);
+int cpu_subsys_down(struct device *dev);
#else /* CONFIG_HOTPLUG_CPU */
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e16695b841de..087c10dbfb99 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1045,11 +1045,20 @@ static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
return err;
}
-int cpu_down(unsigned int cpu)
+static int cpu_down(unsigned int cpu)
{
return do_cpu_down(cpu, CPUHP_OFFLINE);
}
-EXPORT_SYMBOL(cpu_down);
+
+/*
+ * This function is meant to be used by device core cpu subsystem.
+ *
+ * Other subsystems should use device_offline(get_cpu_device(cpu)) instead.
+ */
+int cpu_subsys_down(struct device *dev)
+{
+ return cpu_down(dev->id);
+}
#else
#define takedown_cpu NULL
@@ -1191,11 +1200,20 @@ static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
return err;
}
-int cpu_up(unsigned int cpu)
+static int cpu_up(unsigned int cpu)
{
return do_cpu_up(cpu, CPUHP_ONLINE);
}
-EXPORT_SYMBOL_GPL(cpu_up);
+
+/*
+ * This function is meant to be used by device core cpu subsystem.
+ *
+ * Other subsystems should use device_online(get_cpu_device(cpu)) instead.
+ */
+int cpu_subsys_up(struct device *dev)
+{
+ return cpu_up(dev->id);
+}
int hibernation_bringup_sleep_cpu(unsigned int sleep_cpu)
{
--
2.17.1
On Wed, 30 Oct 2019, Qais Yousef wrote:
> -int cpu_down(unsigned int cpu)
> +static int cpu_down(unsigned int cpu)
> {
> return do_cpu_down(cpu, CPUHP_OFFLINE);
> }
> -EXPORT_SYMBOL(cpu_down);
The exports should be gone already at this point, right?
> +/*
> + * This function is meant to be used by device core cpu subsystem.
> + *
> + * Other subsystems should use device_offline(get_cpu_device(cpu)) instead.
> + */
Can you please use proper kernel-doc function documentation?
Thanks,
tglx
On 11/19/19 23:25, Thomas Gleixner wrote:
> On Wed, 30 Oct 2019, Qais Yousef wrote:
> > -int cpu_down(unsigned int cpu)
> > +static int cpu_down(unsigned int cpu)
> > {
> > return do_cpu_down(cpu, CPUHP_OFFLINE);
> > }
> > -EXPORT_SYMBOL(cpu_down);
>
> The exports should be gone already at this point, right?
Yes. The only in-kernel user was the torture test.
> > +/*
> > + * This function is meant to be used by device core cpu subsystem.
> > + *
> > + * Other subsystems should use device_offline(get_cpu_device(cpu)) instead.
> > + */
>
> Can you please use proper kernel-doc function documentation?
Will do.
Thanks
--
Qais Yousef