[...]

quoted

quoted

+ * zynqmp_r5_cluster_init()
+ * Create and initialize zynqmp_r5_cluster type object
+ *
+ * @cluster: pointer to zynqmp_r5_cluster type object
+ *
+ * Return: 0 for success and error code for failure.
+ */
+static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
+{
+	struct device *dev = cluster->dev;
+	struct device_node *dev_node = dev_of_node(dev);
+	struct device_node *child;
+	struct platform_device *child_pdev;
+	int core_count = 0, ret, i;
+	enum zynqmp_r5_cluster_mode cluster_mode = LOCKSTEP_MODE;
+	struct zynqmp_r5_core **r5_cores;
+
+	ret = of_property_read_u32(dev_node, "xlnx,cluster-mode", &cluster_mode);
+
+	/*
+	 * on success returns 0, if not defined then returns -EINVAL,
+	 * In that case, default is LOCKSTEP mode
+	 */
+	if (ret != -EINVAL && ret != 0) {
+		dev_err(dev, "Invalid xlnx,cluster-mode property\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * For now driver only supports split mode and lockstep mode.
+	 * fail driver probe if either of that is not set in dts
+	 */
+	if (cluster_mode == SINGLE_CPU_MODE) {
+		dev_err(dev, "driver does not support single cpu mode\n");
+		return -EINVAL;
+	} else if ((cluster_mode != SPLIT_MODE &&
+		   cluster_mode != LOCKSTEP_MODE)) {
+		dev_err(dev, "Invalid cluster mode\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Number of cores is decided by number of child nodes of
+	 * r5f subsystem node in dts. If Split mode is used in dts
+	 * 2 child nodes are expected.
+	 * In lockstep mode if two child nodes are available,
+	 * only use first child node and consider it as core0
+	 * and ignore core1 dt node.
+	 */
+	core_count = of_get_available_child_count(dev_node);
+	if (core_count <= 0) {
+		dev_err(dev, "Invalid number of r5 cores %d", core_count);
+		return -EINVAL;
+	} else if (cluster_mode == SPLIT_MODE && core_count != 2) {
+		dev_err(dev, "Invalid number of r5 cores for split mode\n");
+		return -EINVAL;
+	} else if (cluster_mode == LOCKSTEP_MODE && core_count == 2) {
+		dev_warn(dev, "Only r5 core0 will be used\n");
+		core_count = 1;
+	}
+
+	r5_cores = devm_kcalloc(dev, core_count,
+				sizeof(struct zynqmp_r5_core *), GFP_KERNEL);
+	if (!r5_cores)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_available_child_of_node(dev_node, child) {
+		child_pdev = of_find_device_by_node(child);
+		if (!child_pdev) {
+			of_node_put(child);
+			return -ENODEV;
+		}
+
+		/* create and add remoteproc instance of type struct rproc */
+		r5_cores[i] = zynqmp_r5_add_rproc_core(&child_pdev->dev);

Function zynqmp_r5_add_rproc_core() returns an error code on error that is never
checked.

quoted

+		r5_cores[i]->dev = &child_pdev->dev;

This will result in a kernel stack trace if zynqmp_r5_add_rproc_core() fails.

Sure I will fix it.

quoted

quoted

+		if (!r5_cores[i]->dev) {
+			dev_err(dev, "can't get device for r5 core %d\n", i);
+			of_node_put(child);
+			return -ENODEV;
+		}

And here the validity of child_pdev->dev is checked _after_ it has been passed
to zynqmp_r5_add_rproc_core().  This check should not be needed if proper
error handling is done above.

I agree.

quoted

quoted

+
+		r5_cores[i]->np = dev_of_node(r5_cores[i]->dev);
+		if (!r5_cores[i]->np) {
+			dev_err(dev, "can't get device node for r5 core %d\n", i);
+			of_node_put(child);

As mention in the documentation for of_find_device_by_node(), the function takes
a reference to child_pdev->dev that needs to be released with put_device().  In
fact I don't see the reference dropped anywhere, even when the driver is
released.

I agree. I want to use r5_cores[i]->dev throughout driver so,

Is it fine if I use put_device() during driver release i.e. function
zynqmp_r5_cluster_exit( ) ?

Yes, that would be the right place to do it.

quoted

Moreover, if we end up here for r5_cores[1], resources acquired for r5_core[0]
are not released.

Most of the resources (such as zynqmp_r5_rproc_ops and r5_rproc objects) for
r5_core[0] are allocated using devm_* API,

so I believe it will be de-allocated when driver probe fails and driver
exits.

If r5_cores[1] fails, then r5_cores[0]->np needs to be released here. I will
find out mechanism to take care of this.

Please let me know if I am missing anything here.

I'll take another look in your next revision.

quoted

quoted

+			return -ENODEV;
+		}
+
+		i++;
+
+		/*
+		 * If two child nodes are available in dts in lockstep mode,
+		 * then ignore second child node.
+		 */
+		if (i == core_count) {
+			of_node_put(child);
+			break;
+		}
+		of_node_put(child);

This one is not needed as it is already done by the
for_each_available_child_of_node() loop.

Ok I will remove it.

quoted

More comments tomorrow.

Thanks,
Mathieu

quoted

+	}
+
+	cluster->mode = cluster_mode;
+	cluster->core_count = core_count;
+	cluster->r5_cores = r5_cores;
+
+	ret = zynqmp_r5_core_init(cluster);
+	if (ret < 0) {
+		dev_err(dev, "failed to init r5 core err %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void zynqmp_r5_cluster_exit(void *data)
+{
+	struct platform_device *pdev = (struct platform_device *)data;
+
+	platform_set_drvdata(pdev, NULL);
+
+	pr_info("Exit r5f subsystem driver\n");
+}
+
+/*
+ * zynqmp_r5_remoteproc_probe()
+ *
+ * @pdev: domain platform device for R5 cluster
+ *
+ * called when driver is probed, for each R5 core specified in DT,
+ * setup as needed to do remoteproc-related operations
+ *
+ * Return: 0 for success, negative value for failure.
+ */
+static int zynqmp_r5_remoteproc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct zynqmp_r5_cluster *cluster;
+	struct device *dev = &pdev->dev;
+
+	cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
+	if (!cluster)
+		return -ENOMEM;
+
+	cluster->dev = dev;
+
+	ret = devm_of_platform_populate(dev);
+	if (ret) {
+		dev_err(dev, "failed to populate platform dev %d\n", ret);
+		return ret;
+	}
+
+	/* wire in so each core can be cleaned up at driver remove */
+	platform_set_drvdata(pdev, cluster);
+
+	ret = devm_add_action_or_reset(dev, zynqmp_r5_cluster_exit, pdev);
+	if (ret)
+		return ret;
+
+	ret = zynqmp_r5_cluster_init(cluster);
+	if (ret) {
+		dev_err(dev, "Invalid r5f subsystem device tree\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/* Match table for OF platform binding */
+static const struct of_device_id zynqmp_r5_remoteproc_match[] = {
+	{ .compatible = "xlnx,zynqmp-r5fss", },
+	{ /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, zynqmp_r5_remoteproc_match);
+
+static struct platform_driver zynqmp_r5_remoteproc_driver = {
+	.probe = zynqmp_r5_remoteproc_probe,
+	.driver = {
+		.name = "zynqmp_r5_remoteproc",
+		.of_match_table = zynqmp_r5_remoteproc_match,
+	},
+};
+module_platform_driver(zynqmp_r5_remoteproc_driver);
+
+MODULE_DESCRIPTION("Xilinx R5F remote processor driver");
+MODULE_AUTHOR("Xilinx Inc.");
+MODULE_LICENSE("GPL v2");
-- 
2.25.1

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