bus/fsl-mc: Export dprc_scan/dprc_remove functions to be used by multiple entities

Currently the DPRC scan function is used only by the bus driver.
But the same functionality will be needed by the VFIO driver.
To support this, the dprc scan function was exported and a little
bit adjusted to fit both scenarios. Also the scan mutex initialization
is done when the bus object is created, not in dprc_probe in order
to be used by both VFIO and bus driver.
Similarily dprc_remove_devices is exported to be used by VFIO.

Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
Link: https://lore.kernel.org/r/20200929085441.17448-8-diana.craciun@oss.nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/fsl-mc/dprc-driver.c

@@ -81,9 +81,9 @@ static int __fsl_mc_device_remove(struct device *dev, void *data)
  * the MC by removing devices that represent MC objects that have
  * been dynamically removed in the physical DPRC.
  */
-static void dprc_remove_devices(struct fsl_mc_device *mc_bus_dev,
-				struct fsl_mc_obj_desc *obj_desc_array,
-				int num_child_objects_in_mc)
+void dprc_remove_devices(struct fsl_mc_device *mc_bus_dev,
+			 struct fsl_mc_obj_desc *obj_desc_array,
+			 int num_child_objects_in_mc)
 {
 	if (num_child_objects_in_mc != 0) {
 		/*
@@ -105,6 +105,7 @@ static void dprc_remove_devices(struct fsl_mc_device *mc_bus_dev,
 				      __fsl_mc_device_remove);
 	}
 }
+EXPORT_SYMBOL_GPL(dprc_remove_devices);
 
 static int __fsl_mc_device_match(struct device *dev, void *data)
 {
@@ -354,9 +355,10 @@ static int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
  * bus driver with the actual state of the MC by adding and removing
  * devices as appropriate.
  */
-static int dprc_scan_container(struct fsl_mc_device *mc_bus_dev)
+int dprc_scan_container(struct fsl_mc_device *mc_bus_dev,
+			bool alloc_interrupts)
 {
-	int error;
+	int error = 0;
 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
 
 	fsl_mc_init_all_resource_pools(mc_bus_dev);
@@ -365,16 +367,12 @@ static int dprc_scan_container(struct fsl_mc_device *mc_bus_dev)
 	 * Discover objects in the DPRC:
 	 */
 	mutex_lock(&mc_bus->scan_mutex);
-	error = dprc_scan_objects(mc_bus_dev, true);
+	error = dprc_scan_objects(mc_bus_dev, alloc_interrupts);
 	mutex_unlock(&mc_bus->scan_mutex);
-	if (error < 0) {
-		fsl_mc_cleanup_all_resource_pools(mc_bus_dev);
-		return error;
-	}
 
-	return 0;
+	return error;
 }
-
+EXPORT_SYMBOL_GPL(dprc_scan_container);
 /**
  * dprc_irq0_handler - Regular ISR for DPRC interrupt 0
  *
@@ -683,12 +681,10 @@ static int dprc_probe(struct fsl_mc_device *mc_dev)
 		goto error_cleanup_open;
 	}
 
-	mutex_init(&mc_bus->scan_mutex);
-
 	/*
 	 * Discover MC objects in DPRC object:
 	 */
-	error = dprc_scan_container(mc_dev);
+	error = dprc_scan_container(mc_dev, true);
 	if (error < 0)
 		goto error_cleanup_open;
 

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

@@ -678,6 +678,7 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
 		if (!mc_bus)
 			return -ENOMEM;
 
+		mutex_init(&mc_bus->scan_mutex);
 		mc_dev = &mc_bus->mc_dev;
 	} else {
 		/*

include/linux/fsl/mc.h

@@ -531,6 +531,13 @@ int dprc_reset_container(struct fsl_mc_io *mc_io,
 			 int child_container_id,
 			 u32 options);
 
+int dprc_scan_container(struct fsl_mc_device *mc_bus_dev,
+			bool alloc_interrupts);
+
+void dprc_remove_devices(struct fsl_mc_device *mc_bus_dev,
+			 struct fsl_mc_obj_desc *obj_desc_array,
+			 int num_child_objects_in_mc);
+
 /*
  * Data Path Buffer Pool (DPBP) API
  * Contains initialization APIs and runtime control APIs for DPBP