On Tue, 4 Jan 2022 21:42:09 +0000
Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
These macros are defined conditionally, according to CONFIG_PM:
- if CONFIG_PM is enabled, these macros resolve to
DEFINE_SIMPLE_DEV_PM_OPS(), and the dev_pm_ops symbol will be
exported.
- if CONFIG_PM is disabled, these macros will result in a dummy
static
dev_pm_ops to be created with the __maybe_unused flag. The
dev_pm_ops
will then be discarded by the compiler, along with the provided
callback functions if they are not used anywhere else.
In the second case, the symbol is not exported, which should be
perfectly fine - users of the symbol should all use the pm_ptr() or
pm_sleep_ptr() macro, so the dev_pm_ops marked as "extern" in the
client's code will never be accessed.
Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
---
include/linux/pm.h | 33 ++++++++++++++++++++++++++++++---
1 file changed, 30 insertions(+), 3 deletions(-)
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 389e600df233..a1ce29566aea 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -8,6 +8,7 @@
#ifndef _LINUX_PM_H
#define _LINUX_PM_H
+#include <linux/export.h>
#include <linux/list.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>
@@ -357,14 +358,40 @@ struct dev_pm_ops {
#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
#endif
+#define _DEFINE_DEV_PM_OPS(name, \
+ suspend_fn, resume_fn, \
+ runtime_suspend_fn, runtime_resume_fn, idle_fn) \
+const struct dev_pm_ops name = { \
+ SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
+ RUNTIME_PM_OPS(runtime_suspend_fn, runtime_resume_fn, idle_fn) \
+}
+
one blank line probably enough.
+
/*
* Use this if you want to use the same suspend and resume
callbacks for suspend
* to RAM and hibernation.
*/
#define DEFINE_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
-const struct dev_pm_ops name = { \
- SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
-}
+ _DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL)
+
+#ifdef CONFIG_PM
+#define _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn,
runtime_suspend_fn, \
+ runtime_resume_fn, idle_fn, sec) \
+ _DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn,
runtime_suspend_fn, \
+ runtime_resume_fn, idle_fn); \
+ _EXPORT_SYMBOL(name, sec)
+#else
+#define _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn,
runtime_suspend_fn, \
+ runtime_resume_fn, idle_fn, sec) \
+static __maybe_unused _DEFINE_DEV_PM_OPS(__static_##name,
suspend_fn, \
+ resume_fn, runtime_suspend_fn, \
+ runtime_resume_fn, idle_fn)
+#endif
+
+#define EXPORT_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
+ _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL,
"")
+#define EXPORT_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
+ _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL,
"_gpl")
So you can get away with these two cases because the
SYSTEM_SLEEP_PM_OPS() all have
pm_sleep_ptr() wrappers. However, _EXPORT_DEV_PM_OPS() could be used
directly and
would require __maybe_unused for the RUNTIME_PM_OPS() parameters
which isn't ideal.
