Re: [PATCH v3 6/6] drivers: remoteproc: Add Xilinx r5 remoteproc driver

From: Tanmay Shah
Date: Tue Feb 22 2022 - 13:08:26 EST


On 2/22/22 8:57 AM, Mathieu Poirier wrote:
[...]

+/**
+ * zynqmp_r5_get_tcm_node()
+ * Ideally this function should parse tcm node and store information
+ * in r5_core instance. We will use hardcoded TCM information from
+ * driver for now in this function.
+ *
+ * @cluster: pointer to zynqmp_r5_cluster type object
+ *
+ * Return: 0 for success and error code for failure.
+ */
+static int zynqmp_r5_get_tcm_node(struct zynqmp_r5_cluster *cluster)
+{
+ int tcm_bank_count, tcm_node;
+ int i = 0, j;
Variable @i doesn't need to be initialised.
Agree.
+ struct zynqmp_r5_core *r5_core;
+ const struct mem_bank_data *tcm = zynqmp_tcm_banks;
+ struct device *dev = cluster->dev;
+
+ /*
+ * ToDo: Use predefined TCM address space values from driver until
+ * system-dt spec is not final for TCM
+ */
+ tcm_bank_count = ARRAY_SIZE(zynqmp_tcm_banks);
+
+ /* count per core tcm banks */
+ tcm_bank_count = tcm_bank_count / cluster->core_count;
+
+ /* r5 core 0 will use all of TCM banks in lockstep mode.
+ * In split mode, r5 core0 will use 128k and r5 core1 will use another
+ * 128k. Assign TCM banks to each core accordingly
+ */
Comment format problem.
My bad. I will fix it.
+ tcm_node = 0;
+ for (i = 0; i < cluster->core_count; i++) {
+ r5_core = cluster->r5_cores[i];
+ r5_core->tcm_banks = devm_kcalloc(dev, tcm_bank_count,
+ sizeof(struct mem_bank_data),
+ GFP_KERNEL);
+ if (!r5_core->tcm_banks)
+ return -ENOMEM;
+
+ for (j = 0; j < tcm_bank_count; j++) {
+ /* Use pre-defined TCM reg values.
+ * Eventually this should be replaced by values
+ * parsed from dts.
+ */
Same. I commented on that in my previous review of this set.
Yes. I will fix it.
+ r5_core->tcm_banks[j].addr = tcm[tcm_node].addr;
+ r5_core->tcm_banks[j].size = tcm[tcm_node].size;
+ r5_core->tcm_banks[j].pm_domain_id = tcm[tcm_node].pm_domain_id;
+ r5_core->tcm_banks[j].bank_name = tcm[tcm_node].bank_name;
+ tcm_node++;
+ }
+
+ r5_core->tcm_bank_count = tcm_bank_count;
Why do we need to copy the exact same information from zynqmp_tcm_banks to ->tcm_banks? Why can't ->tcm_banks point to an offset in zynqmp_tcm_banks and ->tcm_bank_count set accordingly?
zynqmp_tcm_banks is global variable. If I use ->tcm_banks point to offset of
zynqmp_tcm_banks and use it in driver, that section of code won't be thread
safe anymore.

I might have to use mutex to protect it. So Instead of pointing it to global
variable, I decided to copy information from global variable to ->tcm_banks.
As far as I can tell ->tcm_banks is a read-only field and as such shouldn't
need mutext protection.

Thanks,
Mathieu

Ok, in that case I will point to offset in zynqmp_tcm_banks as suggested.

Rest of the comments looks good, and I will address them in next revision.

Thanks,

Tanmay

+ }
+
+ return 0;
+}
+
+/**
+ * zynqmp_r5_get_mem_region_node()
+ * parse memory-region property from dt node and add
+ * memory region carveouts
+ *
+ * @r5_core: pointer to zynqmp_r5_core type object
+ *
+ * Return: 0 for success and error code for failure.
+ */
+static int zynqmp_r5_get_mem_region_node(struct zynqmp_r5_core *r5_core)
+{
+ int res_mem_count, i, ret;
+ struct device *dev;
+ struct device_node *np, *rmem_np;
+ struct reserved_mem *rmem;
+
+ dev = r5_core->dev;
+
+ np = r5_core->np;
+
+ res_mem_count = of_property_count_elems_of_size(np, "memory-region",
+ sizeof(phandle));
+ if (res_mem_count <= 0) {
+ dev_warn(dev, "failed to get memory-region property %d\n",
+ res_mem_count);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < res_mem_count; i++) {
+ rmem_np = of_parse_phandle(np, "memory-region", i);
+ if (!rmem_np)
+ return -EINVAL;
+
+ rmem = of_reserved_mem_lookup(rmem_np);
+ if (!rmem) {
+ of_node_put(rmem_np);
+ return -EINVAL;
What happens to previously allocated regions when there is a failure?
Right, I need to unmap memory and use kfree(rmem) to de-allocate memory.

+ }
+
+ ret = add_mem_regions_carveout(r5_core, rmem);
+ if (ret)
+ dev_warn(dev, "failed to get reserve mem regions %d\n",
+ ret);
Same here.
Here as well. I will release reserved mem dev with
of_reserved_mem_device_release API.

One more thing. I moved add_mem_regions_carveout from parse_fw to
zynqmp_r5_get_mem_region_node.

However, I believe I should move it back to parse_fw.

Following test case is failing in when add_mem_regions_carveout is not
available in parse_fw:

load_rpu_fw -> start rpu -> stop rpu -> start rpu again

In above case, during mem regions are not added again.

Is it fine, if I move this add_mem_regions_carveout back to
zynqmp_r5_parse_fw ?

I am out of time for this set. Please address comments provided up to here and
we will see about the rest in a future revision.

Thanks,
Mathieu

+
+ of_node_put(rmem_np);
+ }
+
+ return 0;
+}
+
+/*
+ * zynqmp_r5_core_init()
+ * Create and initialize zynqmp_r5_core type object
+ *
+ * @cluster: pointer to zynqmp_r5_cluster type object
+ *
+ * Return: 0 for success and error code for failure.
+ */
+static int zynqmp_r5_core_init(struct zynqmp_r5_cluster *cluster)
+{
+ int ret, i;
+ struct zynqmp_r5_core *r5_core;
+ struct device *dev = cluster->dev;
+
+ ret = zynqmp_r5_get_tcm_node(cluster);
+ if (ret < 0) {
+ dev_err(dev, "can't get tcm node, err %d\n", ret);
+ return ret;
+ }
+
+ for (i = 0; i < cluster->core_count; i++) {
+ r5_core = cluster->r5_cores[i];
+
+ ret = zynqmp_r5_get_mem_region_node(r5_core);
+ if (ret)
+ dev_warn(dev, "memory-region prop failed %d\n", ret);
+
+ /* Initialize r5 cores with power-domains parsed from dts */
+ ret = of_property_read_u32_index(r5_core->np, "power-domains",
+ 1, &r5_core->pm_domain_id);
+ if (ret) {
+ dev_err(dev, "failed to get power-domains property\n");
+ return ret;
+ }
+
+ ret = zynqmp_r5_set_mode(r5_core, cluster->mode);
+ if (ret) {
+ dev_err(dev, "failed to set r5 cluster mode %d, err %d\n",
+ cluster->mode, ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * 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);
+ r5_cores[i]->dev = &child_pdev->dev;
+ if (!r5_cores[i]->dev) {
+ dev_err(dev, "can't get device for r5 core %d\n", i);
+ of_node_put(child);
+ return -ENODEV;
+ }
+
+ 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);
+ 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);
+ }
+
+ 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