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authorQais Yousef <qais.yousef@arm.com>2020-03-23 13:51:10 +0000
committerThomas Gleixner <tglx@linutronix.de>2020-03-25 12:59:38 +0100
commit33c3736ec88811b9b6f6ce2cc8967f6b97c3db5e (patch)
tree7960a1c3986d52a2db8c9fef31b92faa1696843f /kernel/cpu.c
parentb99a26593b5190fac6b5c1f81a7f8cc128a25c98 (diff)
downloadlwn-33c3736ec88811b9b6f6ce2cc8967f6b97c3db5e.tar.gz
lwn-33c3736ec88811b9b6f6ce2cc8967f6b97c3db5e.zip
cpu/hotplug: Hide cpu_up/down()
Use separate functions for the device core to bring a CPU up and down. Users outside the device core must use add/remove_cpu() which will take care of extra housekeeping work like keeping sysfs in sync. Make cpu_up/down() static and replace the extra layer of indirection. [ tglx: Removed the extra wrapper functions and adjusted function names ] Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200323135110.30522-18-qais.yousef@arm.com
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c42
1 files changed, 28 insertions, 14 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 4783d811ccf8..30848496cbc7 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1041,7 +1041,7 @@ static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target)
return _cpu_down(cpu, 0, target);
}
-static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
+static int cpu_down(unsigned int cpu, enum cpuhp_state target)
{
int err;
@@ -1051,11 +1051,18 @@ static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
return err;
}
-int cpu_down(unsigned int cpu)
+/**
+ * cpu_device_down - Bring down a cpu device
+ * @dev: Pointer to the cpu device to offline
+ *
+ * This function is meant to be used by device core cpu subsystem only.
+ *
+ * Other subsystems should use remove_cpu() instead.
+ */
+int cpu_device_down(struct device *dev)
{
- return do_cpu_down(cpu, CPUHP_OFFLINE);
+ return cpu_down(dev->id, CPUHP_OFFLINE);
}
-EXPORT_SYMBOL(cpu_down);
int remove_cpu(unsigned int cpu)
{
@@ -1178,8 +1185,8 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
}
/*
- * The caller of do_cpu_up might have raced with another
- * caller. Ignore it for now.
+ * The caller of cpu_up() might have raced with another
+ * caller. Nothing to do.
*/
if (st->state >= target)
goto out;
@@ -1223,7 +1230,7 @@ out:
return ret;
}
-static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
+static int cpu_up(unsigned int cpu, enum cpuhp_state target)
{
int err = 0;
@@ -1257,11 +1264,18 @@ out:
return err;
}
-int cpu_up(unsigned int cpu)
+/**
+ * cpu_device_up - Bring up a cpu device
+ * @dev: Pointer to the cpu device to online
+ *
+ * This function is meant to be used by device core cpu subsystem only.
+ *
+ * Other subsystems should use add_cpu() instead.
+ */
+int cpu_device_up(struct device *dev)
{
- return do_cpu_up(cpu, CPUHP_ONLINE);
+ return cpu_up(dev->id, CPUHP_ONLINE);
}
-EXPORT_SYMBOL_GPL(cpu_up);
int add_cpu(unsigned int cpu)
{
@@ -1289,7 +1303,7 @@ int bringup_hibernate_cpu(unsigned int sleep_cpu)
if (!cpu_online(sleep_cpu)) {
pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n");
- ret = cpu_up(sleep_cpu);
+ ret = cpu_up(sleep_cpu, CPUHP_ONLINE);
if (ret) {
pr_err("Failed to bring hibernate-CPU up!\n");
return ret;
@@ -1306,7 +1320,7 @@ void bringup_nonboot_cpus(unsigned int setup_max_cpus)
if (num_online_cpus() >= setup_max_cpus)
break;
if (!cpu_online(cpu))
- cpu_up(cpu);
+ cpu_up(cpu, CPUHP_ONLINE);
}
}
@@ -2129,9 +2143,9 @@ static ssize_t write_cpuhp_target(struct device *dev,
goto out;
if (st->state < target)
- ret = do_cpu_up(dev->id, target);
+ ret = cpu_up(dev->id, target);
else
- ret = do_cpu_down(dev->id, target);
+ ret = cpu_down(dev->id, target);
out:
unlock_device_hotplug();
return ret ? ret : count;