genirq/msi: Rename msi_[un]lock_descs()

Now that all abuse is gone and the legit users are converted to
guard(msi_descs_lock), rename the lock functions and document them as
internal.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huwei.com>
Link: https://lore.kernel.org/all/20250313130322.027190131@linutronix.de

Author: KAGA-KOKO

include/linux/msi.h

@@ -224,11 +224,11 @@ struct msi_dev_domain {
 
 int msi_setup_device_data(struct device *dev);
 
-void msi_lock_descs(struct device *dev);
-void msi_unlock_descs(struct device *dev);
+void __msi_lock_descs(struct device *dev);
+void __msi_unlock_descs(struct device *dev);
 
-DEFINE_LOCK_GUARD_1(msi_descs_lock, struct device, msi_lock_descs(_T->lock),
-		    msi_unlock_descs(_T->lock));
+DEFINE_LOCK_GUARD_1(msi_descs_lock, struct device, __msi_lock_descs(_T->lock),
+		    __msi_unlock_descs(_T->lock));
 
 struct msi_desc *msi_domain_first_desc(struct device *dev, unsigned int domid,
 				       enum msi_desc_filter filter);

kernel/irq/msi.c

@@ -338,26 +338,30 @@ int msi_setup_device_data(struct device *dev)
 }
 
 /**
- * msi_lock_descs - Lock the MSI descriptor storage of a device
+ * __msi_lock_descs - Lock the MSI descriptor storage of a device
  * @dev:	Device to operate on
+ *
+ * Internal function for guard(msi_descs_lock). Don't use in code.
  */
-void msi_lock_descs(struct device *dev)
+void __msi_lock_descs(struct device *dev)
 {
 	mutex_lock(&dev->msi.data->mutex);
 }
-EXPORT_SYMBOL_GPL(msi_lock_descs);
+EXPORT_SYMBOL_GPL(__msi_lock_descs);
 
 /**
- * msi_unlock_descs - Unlock the MSI descriptor storage of a device
+ * __msi_unlock_descs - Unlock the MSI descriptor storage of a device
  * @dev:	Device to operate on
+ *
+ * Internal function for guard(msi_descs_lock). Don't use in code.
  */
-void msi_unlock_descs(struct device *dev)
+void __msi_unlock_descs(struct device *dev)
 {
 	/* Invalidate the index which was cached by the iterator */
 	dev->msi.data->__iter_idx = MSI_XA_MAX_INDEX;
 	mutex_unlock(&dev->msi.data->mutex);
 }
-EXPORT_SYMBOL_GPL(msi_unlock_descs);
+EXPORT_SYMBOL_GPL(__msi_unlock_descs);
 
 static struct msi_desc *msi_find_desc(struct msi_device_data *md, unsigned int domid,
 				      enum msi_desc_filter filter)