bus: fsl-mc: automatically add a device_link on fsl_mc_[portal,object]_allocate

Allocatable devices can be acquired by drivers on the fsl-mc bus using
the fsl_mc_portal_allocate or fsl_mc_object_allocate functions. Add a
device link between the consumer device and the supplier device so that
proper resource management is achieved.
Also, adding a link between these devices ensures that a proper unbind
order is respected (ie before the supplier device is unbound from its
respective driver all consumer devices will be notified and unbound
first).

Signed-off-by: Ioana Ciornei <[email protected]>
Reviewed-by: Laurentiu Tudor <[email protected]>
Signed-off-by: Li Yang <[email protected]>

Author: IoanaCiornei

drivers/bus/fsl-mc/fsl-mc-allocator.c

@@ -295,6 +295,14 @@ int __must_check fsl_mc_object_allocate(struct fsl_mc_device *mc_dev,
 	if (!mc_adev)
 		goto error;
 
+	mc_adev->consumer_link = device_link_add(&mc_dev->dev,
+						 &mc_adev->dev,
+						 DL_FLAG_AUTOREMOVE_CONSUMER);
+	if (!mc_adev->consumer_link) {
+		error = -EINVAL;
+		goto error;
+	}
+
 	*new_mc_adev = mc_adev;
 	return 0;
 error:
@@ -321,6 +329,9 @@ void fsl_mc_object_free(struct fsl_mc_device *mc_adev)
 		return;
 
 	fsl_mc_resource_free(resource);
+
+	device_link_del(mc_adev->consumer_link);
+	mc_adev->consumer_link = NULL;
 }
 EXPORT_SYMBOL_GPL(fsl_mc_object_free);
 

drivers/bus/fsl-mc/mc-io.c

@@ -209,9 +209,19 @@ int __must_check fsl_mc_portal_allocate(struct fsl_mc_device *mc_dev,
 	if (error < 0)
 		goto error_cleanup_resource;
 
+	dpmcp_dev->consumer_link = device_link_add(&mc_dev->dev,
+						   &dpmcp_dev->dev,
+						   DL_FLAG_AUTOREMOVE_CONSUMER);
+	if (!dpmcp_dev->consumer_link) {
+		error = -EINVAL;
+		goto error_cleanup_mc_io;
+	}
+
 	*new_mc_io = mc_io;
 	return 0;
 
+error_cleanup_mc_io:
+	fsl_destroy_mc_io(mc_io);
 error_cleanup_resource:
 	fsl_mc_resource_free(resource);
 	return error;
@@ -244,6 +254,9 @@ void fsl_mc_portal_free(struct fsl_mc_io *mc_io)
 
 	fsl_destroy_mc_io(mc_io);
 	fsl_mc_resource_free(resource);
+
+	device_link_del(dpmcp_dev->consumer_link);
+	dpmcp_dev->consumer_link = NULL;
 }
 EXPORT_SYMBOL_GPL(fsl_mc_portal_free);
 

include/linux/fsl/mc.h

@@ -193,6 +193,7 @@ struct fsl_mc_device {
 	struct resource *regions;
 	struct fsl_mc_device_irq **irqs;
 	struct fsl_mc_resource *resource;
+	struct device_link *consumer_link;
 };
 
 #define to_fsl_mc_device(_dev) \