iio: trigger: move trig->owner init to trigger allocate() stage

To provide a new IIO trigger to the IIO core, usually driver executes the
following pipeline: allocate()/register()/get(). Before, IIO core assigned
trig->owner as a pointer to the module which registered this trigger at
the register() stage. But actually the trigger object is owned by the
module earlier, on the allocate() stage, when trigger object is
successfully allocated for the driver.

This patch moves trig->owner initialization from register()
stage of trigger initialization pipeline to allocate() stage to
eliminate all misunderstandings and time gaps between trigger object
creation and owner acquiring.

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Link: https://lore.kernel.org/r/20220601174837.20292-1-ddrokosov@sberdevices.ru
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 25 insertions, 21 deletions

diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
index 26d610d4cbb8..efc01584b3f9 100644
--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -63,13 +63,10 @@ ATTRIBUTE_GROUPS(iio_trig_dev);
 
 static struct iio_trigger *__iio_trigger_find_by_name(const char *name);
 
-int __iio_trigger_register(struct iio_trigger *trig_info,
-			   struct module *this_mod)
+int iio_trigger_register(struct iio_trigger *trig_info)
 {
 	int ret;
 
-	trig_info->owner = this_mod;
-
 	trig_info->id = ida_alloc(&iio_trigger_ida, GFP_KERNEL);
 	if (trig_info->id < 0)
 		return trig_info->id;
@@ -100,7 +97,7 @@ error_unregister_id:
 	ida_free(&iio_trigger_ida, trig_info->id);
 	return ret;
 }
-EXPORT_SYMBOL(__iio_trigger_register);
+EXPORT_SYMBOL(iio_trigger_register);
 
 void iio_trigger_unregister(struct iio_trigger *trig_info)
 {
@@ -547,8 +544,9 @@ static void iio_trig_subirqunmask(struct irq_data *d)
 	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
 }
 
-static __printf(2, 0)
+static __printf(3, 0)
 struct iio_trigger *viio_trigger_alloc(struct device *parent,
+				       struct module *this_mod,
 				       const char *fmt,
 				       va_list vargs)
 {
@@ -578,6 +576,8 @@ struct iio_trigger *viio_trigger_alloc(struct device *parent,
 
 	INIT_LIST_HEAD(&trig->list);
 
+	trig->owner = this_mod;
+
 	trig->subirq_chip.name = trig->name;
 	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
 	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
@@ -598,8 +598,9 @@ free_trig:
 }
 
 /**
- * iio_trigger_alloc - Allocate a trigger
+ * __iio_trigger_alloc - Allocate a trigger
  * @parent:		Device to allocate iio_trigger for
+ * @this_mod:		module allocating the trigger
  * @fmt:		trigger name format. If it includes format
  *			specifiers, the additional arguments following
  *			format are formatted and inserted in the resulting
@@ -607,18 +608,20 @@ free_trig:
  * RETURNS:
  * Pointer to allocated iio_trigger on success, NULL on failure.
  */
-struct iio_trigger *iio_trigger_alloc(struct device *parent, const char *fmt, ...)
+struct iio_trigger *__iio_trigger_alloc(struct device *parent,
+					struct module *this_mod,
+					const char *fmt, ...)
 {
 	struct iio_trigger *trig;
 	va_list vargs;
 
 	va_start(vargs, fmt);
-	trig = viio_trigger_alloc(parent, fmt, vargs);
+	trig = viio_trigger_alloc(parent, this_mod, fmt, vargs);
 	va_end(vargs);
 
 	return trig;
 }
-EXPORT_SYMBOL(iio_trigger_alloc);
+EXPORT_SYMBOL(__iio_trigger_alloc);
 
 void iio_trigger_free(struct iio_trigger *trig)
 {
@@ -633,10 +636,11 @@ static void devm_iio_trigger_release(struct device *dev, void *res)
 }
 
 /**
- * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
+ * __devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
  * Managed iio_trigger_alloc.  iio_trigger allocated with this function is
  * automatically freed on driver detach.
  * @parent:		Device to allocate iio_trigger for
+ * @this_mod:		module allocating the trigger
  * @fmt:		trigger name format. If it includes format
  *			specifiers, the additional arguments following
  *			format are formatted and inserted in the resulting
@@ -646,7 +650,9 @@ static void devm_iio_trigger_release(struct device *dev, void *res)
  * RETURNS:
  * Pointer to allocated iio_trigger on success, NULL on failure.
  */
-struct iio_trigger *devm_iio_trigger_alloc(struct device *parent, const char *fmt, ...)
+struct iio_trigger *__devm_iio_trigger_alloc(struct device *parent,
+					     struct module *this_mod,
+					     const char *fmt, ...)
 {
 	struct iio_trigger **ptr, *trig;
 	va_list vargs;
@@ -658,7 +664,7 @@ struct iio_trigger *devm_iio_trigger_alloc(struct device *parent, const char *fm
 
 	/* use raw alloc_dr for kmalloc caller tracing */
 	va_start(vargs, fmt);
-	trig = viio_trigger_alloc(parent, fmt, vargs);
+	trig = viio_trigger_alloc(parent, this_mod, fmt, vargs);
 	va_end(vargs);
 	if (trig) {
 		*ptr = trig;
@@ -669,7 +675,7 @@ struct iio_trigger *devm_iio_trigger_alloc(struct device *parent, const char *fm
 
 	return trig;
 }
-EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
+EXPORT_SYMBOL_GPL(__devm_iio_trigger_alloc);
 
 static void devm_iio_trigger_unreg(void *trigger_info)
 {
@@ -677,10 +683,9 @@ static void devm_iio_trigger_unreg(void *trigger_info)
 }
 
 /**
- * __devm_iio_trigger_register - Resource-managed iio_trigger_register()
+ * devm_iio_trigger_register - Resource-managed iio_trigger_register()
  * @dev:	device this trigger was allocated for
  * @trig_info:	trigger to register
- * @this_mod:   module registering the trigger
  *
  * Managed iio_trigger_register().  The IIO trigger registered with this
  * function is automatically unregistered on driver detach. This function
@@ -690,19 +695,18 @@ static void devm_iio_trigger_unreg(void *trigger_info)
  * RETURNS:
  * 0 on success, negative error number on failure.
  */
-int __devm_iio_trigger_register(struct device *dev,
-				struct iio_trigger *trig_info,
-				struct module *this_mod)
+int devm_iio_trigger_register(struct device *dev,
+			      struct iio_trigger *trig_info)
 {
 	int ret;
 
-	ret = __iio_trigger_register(trig_info, this_mod);
+	ret = iio_trigger_register(trig_info);
 	if (ret)
 		return ret;
 
 	return devm_add_action_or_reset(dev, devm_iio_trigger_unreg, trig_info);
 }
-EXPORT_SYMBOL_GPL(__devm_iio_trigger_register);
+EXPORT_SYMBOL_GPL(devm_iio_trigger_register);
 
 bool iio_trigger_using_own(struct iio_dev *indio_dev)
 {