staging: fsl-mc: Populate the IRQ pool for an MC bus instance

Scan the corresponding DPRC container to get total count
of IRQs needed by all its child DPAA2 objects. Then,
preallocate a set of MSI IRQs with the DPRC's ICID
(GIT-ITS device Id) to populate the the DPRC's IRQ pool.
Each child DPAA2 object in the DPRC and the DPRC object itself
will allocate their necessary MSI IRQs from the DPRC's IRQ pool,
in their driver probe function.
Signed-off-by: J. German Rivera <German.Rivera@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -241,6 +241,7 @@ static void dprc_cleanup_all_resource_pools(struct fsl_mc_device *mc_bus_dev)
  * dprc_scan_objects - Discover objects in a DPRC
  *
  * @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object
+ * @total_irq_count: total number of IRQs needed by objects in the DPRC.
  *
  * Detects objects added and removed from a DPRC and synchronizes the
  * state of the Linux bus driver, MC by adding and removing
@@ -254,11 +255,13 @@ static void dprc_cleanup_all_resource_pools(struct fsl_mc_device *mc_bus_dev)
  * populated before they can get allocation requests from probe callbacks
  * of the device drivers for the non-allocatable devices.
  */
-int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev)
+int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
+		      unsigned int *total_irq_count)
 {
 	int num_child_objects;
 	int dprc_get_obj_failures;
 	int error;
+	unsigned int irq_count = mc_bus_dev->obj_desc.irq_count;
 	struct dprc_obj_desc *child_obj_desc_array = NULL;
 
 	error = dprc_get_obj_count(mc_bus_dev->mc_io,
@@ -307,6 +310,7 @@ int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev)
 				continue;
 			}
 
+			irq_count += obj_desc->irq_count;
 			dev_dbg(&mc_bus_dev->dev,
 				"Discovered object: type %s, id %d\n",
 				obj_desc->type, obj_desc->id);
@@ -319,6 +323,7 @@ int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev)
 		}
 	}
 
+	*total_irq_count = irq_count;
 	dprc_remove_devices(mc_bus_dev, child_obj_desc_array,
 			    num_child_objects);
 
@@ -344,6 +349,7 @@ EXPORT_SYMBOL_GPL(dprc_scan_objects);
 int dprc_scan_container(struct fsl_mc_device *mc_bus_dev)
 {
 	int error;
+	unsigned int irq_count;
 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
 
 	dprc_init_all_resource_pools(mc_bus_dev);
@@ -352,11 +358,25 @@ 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);
+	error = dprc_scan_objects(mc_bus_dev, &irq_count);
 	mutex_unlock(&mc_bus->scan_mutex);
 	if (error < 0)
 		goto error;
 
+	if (dev_get_msi_domain(&mc_bus_dev->dev) && !mc_bus->irq_resources) {
+		if (irq_count > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS) {
+			dev_warn(&mc_bus_dev->dev,
+				 "IRQs needed (%u) exceed IRQs preallocated (%u)\n",
+				 irq_count, FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS);
+		}
+
+		error = fsl_mc_populate_irq_pool(
+				mc_bus,
+				FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS);
+		if (error < 0)
+			goto error;
+	}
+
 	return 0;
 error:
 	dprc_cleanup_all_resource_pools(mc_bus_dev);

drivers/staging/fsl-mc/include/mc-private.h

@@ -114,7 +114,8 @@ void fsl_mc_device_remove(struct fsl_mc_device *mc_dev);
 
 int dprc_scan_container(struct fsl_mc_device *mc_bus_dev);
 
-int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev);
+int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
+		      unsigned int *total_irq_count);
 
 int __init dprc_driver_init(void);