On 16/04/2019 21:39, Frank Li wrote:
[...]
+static int ddr_perf_probe(struct platform_device *pdev)
+{
+ struct ddr_pmu *pmu;
+ struct device_node *np;
+ void __iomem *base;
+ struct resource *iomem;
+ char *name;
+ char *hpname;
+ int num;
+ int ret;
+ u32 irq;
+ const struct of_device_id *of_id =
+ of_match_device(imx_ddr_pmu_dt_ids, &pdev->dev);
+
+ iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, iomem);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ np = pdev->dev.of_node;
+
+ pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
+ if (!pmu)
+ return -ENOMEM;
+
+ num = ddr_perf_init(pmu, base, &pdev->dev);
+
+ name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "ddr%d", num);
+ if (!name)
+ return -ENOMEM;
+
+ hpname = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "perf/imx/ddr%d:online", num);
+ if (!hpname)
+ return -ENOMEM;
+
+ pmu->flags = (uintptr_t) of_id->data;
+
+ cpumask_set_cpu(raw_smp_processor_id(), &pmu->cpu);
+ ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, hpname, NULL,
+ ddr_perf_offline_cpu);
+
+ if (ret < 0) {
+ dev_err(&pdev->dev, "cpuhp_setup_state_multi failed\n");
+ goto ddr_perf_err;
+ }
Since you don't seem to ever remove this state again, this looks like it
would make subsequent loads of the module always fail after it's been
loaded and unloaded once - have you tried that?
Robin.
+
+ pmu->cpuhp_state = ret;
+
+ /* Register the pmu instance for cpu hotplug */
+ cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+
+ ret = perf_pmu_register(&(pmu->pmu), name, -1);
+ if (ret)
+ goto ddr_perf_err;
+
+ /* Request irq */
+ irq = of_irq_get(np, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "Failed to get irq: %d", irq);
+ ret = irq;
+ goto ddr_perf_irq_err;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq,
+ ddr_perf_irq_handler,
+ IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ DDR_PERF_DEV_NAME,
+ pmu);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Request irq failed: %d", ret);
+ goto ddr_perf_irq_err;
+ }
+
+ return 0;
+
+ddr_perf_irq_err:
+ perf_pmu_unregister(&(pmu->pmu));
+
+ddr_perf_err:
+ if (pmu->cpuhp_state)
+ cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+
+ dev_warn(&pdev->dev, "i.MX8 DDR Perf PMU failed (%d), disabled\n", ret);
+ return ret;
+}
+
+static int ddr_perf_remove(struct platform_device *pdev)
+{
+ struct ddr_pmu *pmu = platform_get_drvdata(pdev);
+
+ cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+ perf_pmu_unregister(&pmu->pmu);
+
+ return 0;
+}
+
+static struct platform_driver imx_ddr_pmu_driver = {
+ .driver = {
+ .name = "imx-ddr-pmu",
+ .of_match_table = imx_ddr_pmu_dt_ids,
+ },
+ .probe = ddr_perf_probe,
+ .remove = ddr_perf_remove,
+};
+
+static int __init imx_ddr_pmu_init(void)
+{
+ return platform_driver_register(&imx_ddr_pmu_driver);
+}
+
+module_init(imx_ddr_pmu_init);
+
