Hello Christophe
On 12/14/23 13:06, Christophe Leroy wrote:
...
So you abandonned the idea of using mutex.h ?
I'm not the one who make a choice here. The patch [1] you're talking
about was seen by everyone but it seems like no one had shown interest.
For me personally approach with #define mutex_destroy is not very usual
but if even slight mixing device with mutex.h is unacceptable what else
can we do? Avoiding the need to allocate devm slot for empty
mutex_destroy is more important.
Should I make series #4 with the patch [1] to give it a last chance?
[1]
https://lore.kernel.org/lkml/377e4437-7051-4d88-ae68-1460bcd692e1@xxxxxxxxxx/T/#m3f6df30ffccaccb1df4669a327f349164f572931
I can't see the point to spread mutex functions into devm-helpers.h
Adding a mutex_destroy macro for this purpose looks odd. And if someone
defines a new version of mutex_destroy() and forget the macro, it will
go undetected.
Usually macros of that type serve the purpose of defining a fallback
when the macro is not defined. In that case, when someone adds a new
version without defining the macro, it gets detected because if
conflicts with the fallback.
But in your case it works the other way round, so I will just go undetected.
For me the best solution remains to use mutex.h and have
devm_mutex_init() defined or declared at the same place as mutex_destroy().
Signed-off-by: George Stark <gnstark@xxxxxxxxxxxxxxxxx>
---
include/linux/devm-helpers.h | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/include/linux/devm-helpers.h b/include/linux/devm-helpers.h
index 74891802200d..4043c3481d2e 100644
--- a/include/linux/devm-helpers.h
+++ b/include/linux/devm-helpers.h
@@ -24,6 +24,7 @@
*/
#include <linux/device.h>
+#include <linux/mutex.h>
#include <linux/workqueue.h>
static inline void devm_delayed_work_drop(void *res)
@@ -76,4 +77,30 @@ static inline int devm_work_autocancel(struct device *dev,
return devm_add_action(dev, devm_work_drop, w);
}
+#ifdef mutex_destroy
+static inline void devm_mutex_release(void *res)
+{
+ mutex_destroy(res);
+}
+#endif
+
+/**
+ * devm_mutex_init - Resource-managed mutex initialization
+ * @dev: Device which lifetime mutex is bound to
+ * @lock: Pointer to a mutex
+ *
+ * Initialize mutex which is automatically destroyed when the driver is detached.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+static inline int devm_mutex_init(struct device *dev, struct mutex *lock)
+{
+ mutex_init(lock);
+#ifdef mutex_destroy
+ return devm_add_action_or_reset(dev, devm_mutex_release, lock);
+#else
+ return 0;
+#endif
+}
+
#endif
--
2.25.1
--
Best regards
George
