coresight: Add support for releasing platform specific data

Add a helper to clean up the platform specific data provided
by the firmware. This will be later used for dropping the necessary
references when we switch to the fwnode handles for tracking
connections.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-platform.c

@@ -17,6 +17,7 @@
 #include <linux/cpumask.h>
 #include <asm/smp_plat.h>
 
+#include "coresight-priv.h"
 /*
  * coresight_alloc_conns: Allocate connections record for each output
  * port from the device.
@@ -311,7 +312,7 @@ struct coresight_platform_data *
 coresight_get_platform_data(struct device *dev)
 {
 	int ret = -ENOENT;
-	struct coresight_platform_data *pdata;
+	struct coresight_platform_data *pdata = NULL;
 	struct fwnode_handle *fwnode = dev_fwnode(dev);
 
 	if (IS_ERR_OR_NULL(fwnode))
@@ -329,6 +330,9 @@ coresight_get_platform_data(struct device *dev)
 	if (!ret)
 		return pdata;
 error:
+	if (!IS_ERR_OR_NULL(pdata))
+		/* Cleanup the connection information */
+		coresight_release_platform_data(pdata);
 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(coresight_get_platform_data);

drivers/hwtracing/coresight/coresight-priv.h

@@ -200,4 +200,8 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
 	return 0;
 }
 
+static inline void
+coresight_release_platform_data(struct coresight_platform_data *pdata)
+{}
+
 #endif

drivers/hwtracing/coresight/coresight.c

@@ -1250,6 +1250,8 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
 err_free_csdev:
 	kfree(csdev);
 err_out:
+	/* Cleanup the connection information */
+	coresight_release_platform_data(desc->pdata);
 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(coresight_register);
@@ -1259,6 +1261,7 @@ void coresight_unregister(struct coresight_device *csdev)
 	etm_perf_del_symlink_sink(csdev);
 	/* Remove references of that device in the topology */
 	coresight_remove_conns(csdev);
+	coresight_release_platform_data(csdev->pdata);
 	device_unregister(&csdev->dev);
 }
 EXPORT_SYMBOL_GPL(coresight_unregister);