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Diffstat (limited to 'kernel/reboot.c')
-rw-r--r--kernel/reboot.c87
1 files changed, 62 insertions, 25 deletions
diff --git a/kernel/reboot.c b/kernel/reboot.c
index a091145ee710..b5a71d1ff603 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -315,6 +315,43 @@ static int sys_off_notify(struct notifier_block *nb,
return handler->sys_off_cb(&data);
}
+static struct sys_off_handler platform_sys_off_handler;
+
+static struct sys_off_handler *alloc_sys_off_handler(int priority)
+{
+ struct sys_off_handler *handler;
+ gfp_t flags;
+
+ /*
+ * Platforms like m68k can't allocate sys_off handler dynamically
+ * at the early boot time because memory allocator isn't available yet.
+ */
+ if (priority == SYS_OFF_PRIO_PLATFORM) {
+ handler = &platform_sys_off_handler;
+ if (handler->cb_data)
+ return ERR_PTR(-EBUSY);
+ } else {
+ if (system_state > SYSTEM_RUNNING)
+ flags = GFP_ATOMIC;
+ else
+ flags = GFP_KERNEL;
+
+ handler = kzalloc(sizeof(*handler), flags);
+ if (!handler)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return handler;
+}
+
+static void free_sys_off_handler(struct sys_off_handler *handler)
+{
+ if (handler == &platform_sys_off_handler)
+ memset(handler, 0, sizeof(*handler));
+ else
+ kfree(handler);
+}
+
/**
* register_sys_off_handler - Register sys-off handler
* @mode: Sys-off mode
@@ -345,9 +382,9 @@ register_sys_off_handler(enum sys_off_mode mode,
struct sys_off_handler *handler;
int err;
- handler = kzalloc(sizeof(*handler), GFP_KERNEL);
- if (!handler)
- return ERR_PTR(-ENOMEM);
+ handler = alloc_sys_off_handler(priority);
+ if (IS_ERR(handler))
+ return handler;
switch (mode) {
case SYS_OFF_MODE_POWER_OFF_PREPARE:
@@ -364,7 +401,7 @@ register_sys_off_handler(enum sys_off_mode mode,
break;
default:
- kfree(handler);
+ free_sys_off_handler(handler);
return ERR_PTR(-EINVAL);
}
@@ -391,7 +428,7 @@ register_sys_off_handler(enum sys_off_mode mode,
}
if (err) {
- kfree(handler);
+ free_sys_off_handler(handler);
return ERR_PTR(err);
}
@@ -409,7 +446,7 @@ void unregister_sys_off_handler(struct sys_off_handler *handler)
{
int err;
- if (!handler)
+ if (IS_ERR_OR_NULL(handler))
return;
if (handler->blocking)
@@ -422,7 +459,7 @@ void unregister_sys_off_handler(struct sys_off_handler *handler)
/* sanity check, shall never happen */
WARN_ON(err);
- kfree(handler);
+ free_sys_off_handler(handler);
}
EXPORT_SYMBOL_GPL(unregister_sys_off_handler);
@@ -584,7 +621,23 @@ static void do_kernel_power_off_prepare(void)
*/
void do_kernel_power_off(void)
{
+ struct sys_off_handler *sys_off = NULL;
+
+ /*
+ * Register sys-off handlers for legacy PM callback. This allows
+ * legacy PM callbacks temporary co-exist with the new sys-off API.
+ *
+ * TODO: Remove legacy handlers once all legacy PM users will be
+ * switched to the sys-off based APIs.
+ */
+ if (pm_power_off)
+ sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+ SYS_OFF_PRIO_DEFAULT,
+ legacy_pm_power_off, NULL);
+
atomic_notifier_call_chain(&power_off_handler_list, 0, NULL);
+
+ unregister_sys_off_handler(sys_off);
}
/**
@@ -595,7 +648,8 @@ void do_kernel_power_off(void)
*/
bool kernel_can_power_off(void)
{
- return !atomic_notifier_call_chain_is_empty(&power_off_handler_list);
+ return !atomic_notifier_call_chain_is_empty(&power_off_handler_list) ||
+ pm_power_off;
}
EXPORT_SYMBOL_GPL(kernel_can_power_off);
@@ -630,7 +684,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
void __user *, arg)
{
struct pid_namespace *pid_ns = task_active_pid_ns(current);
- struct sys_off_handler *sys_off = NULL;
char buffer[256];
int ret = 0;
@@ -655,21 +708,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
if (ret)
return ret;
- /*
- * Register sys-off handlers for legacy PM callback. This allows
- * legacy PM callbacks temporary co-exist with the new sys-off API.
- *
- * TODO: Remove legacy handlers once all legacy PM users will be
- * switched to the sys-off based APIs.
- */
- if (pm_power_off) {
- sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
- SYS_OFF_PRIO_DEFAULT,
- legacy_pm_power_off, NULL);
- if (IS_ERR(sys_off))
- return PTR_ERR(sys_off);
- }
-
/* Instead of trying to make the power_off code look like
* halt when pm_power_off is not set do it the easy way.
*/
@@ -727,7 +765,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
break;
}
mutex_unlock(&system_transition_mutex);
- unregister_sys_off_handler(sys_off);
return ret;
}