[PATCH v2] perf: arm_dsu: Support DSU ACPI devices.

From: Tuan Phan
Date: Mon May 11 2020 - 16:33:06 EST


Add ACPI node probing device support. Each DSU ACPI node
defines a "cpus" package with a per cpu MPIDR element.

Signed-off-by: Tuan Phan <tuanphan@xxxxxxxxxxxxxxxxxxxxxx>
---
Changes in v2:
- Removed IRQF_SHARED.
- Fixed ACPI runtime detection.

The ACPI binding spec for DSU ACPI node is under beta and located
in ARM server group under project "ACPI on ARM".

drivers/perf/arm_dsu_pmu.c | 71 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 63 insertions(+), 8 deletions(-)

diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c
index 70968c8..784d177 100644
--- a/drivers/perf/arm_dsu_pmu.c
+++ b/drivers/perf/arm_dsu_pmu.c
@@ -11,6 +11,7 @@
#define DRVNAME PMUNAME "_pmu"
#define pr_fmt(fmt) DRVNAME ": " fmt

+#include <linux/acpi.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/bug.h>
@@ -603,18 +604,21 @@ static struct dsu_pmu *dsu_pmu_alloc(struct platform_device *pdev)
}

/**
- * dsu_pmu_dt_get_cpus: Get the list of CPUs in the cluster.
+ * dsu_pmu_dt_get_cpus: Get the list of CPUs in the cluster
+ * from device tree.
*/
-static int dsu_pmu_dt_get_cpus(struct device_node *dev, cpumask_t *mask)
+static int dsu_pmu_dt_get_cpus(struct platform_device *pdev)
{
int i = 0, n, cpu;
struct device_node *cpu_node;
+ struct dsu_pmu *dsu_pmu =
+ (struct dsu_pmu *) platform_get_drvdata(pdev);

- n = of_count_phandle_with_args(dev, "cpus", NULL);
+ n = of_count_phandle_with_args(pdev->dev.of_node, "cpus", NULL);
if (n <= 0)
return -ENODEV;
for (; i < n; i++) {
- cpu_node = of_parse_phandle(dev, "cpus", i);
+ cpu_node = of_parse_phandle(pdev->dev.of_node, "cpus", i);
if (!cpu_node)
break;
cpu = of_cpu_node_to_id(cpu_node);
@@ -626,11 +630,54 @@ static int dsu_pmu_dt_get_cpus(struct device_node *dev, cpumask_t *mask)
*/
if (cpu < 0)
continue;
- cpumask_set_cpu(cpu, mask);
+ cpumask_set_cpu(cpu, &dsu_pmu->associated_cpus);
}
return 0;
}

+/**
+ * dsu_pmu_acpi_get_cpus: Get the list of CPUs in the cluster
+ * from ACPI.
+ */
+static int dsu_pmu_acpi_get_cpus(struct platform_device *pdev)
+{
+ int i, cpu, ret;
+ const union acpi_object *obj;
+ struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+ struct dsu_pmu *dsu_pmu =
+ (struct dsu_pmu *) platform_get_drvdata(pdev);
+
+ ret = acpi_dev_get_property(adev, "cpus", ACPI_TYPE_PACKAGE, &obj);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < obj->package.count; i++) {
+ /* Each element is the MPIDR of associated cpu */
+ for_each_possible_cpu(cpu) {
+ if (cpu_physical_id(cpu) ==
+ obj->package.elements[i].integer.value)
+ cpumask_set_cpu(cpu, &dsu_pmu->associated_cpus);
+ }
+ }
+ return 0;
+}
+
+static int dsu_pmu_platform_get_cpus(struct platform_device *pdev)
+{
+ int ret = -ENOENT;
+ struct fwnode_handle *fwnode = dev_fwnode(&pdev->dev);
+
+ if (IS_ERR_OR_NULL(fwnode))
+ return ret;
+
+ if (is_of_node(fwnode))
+ ret = dsu_pmu_dt_get_cpus(pdev);
+ else if (is_acpi_device_node(fwnode))
+ ret = dsu_pmu_acpi_get_cpus(pdev);
+
+ return ret;
+}
+
/*
* dsu_pmu_probe_pmu: Probe the PMU details on a CPU in the cluster.
*/
@@ -683,7 +730,9 @@ static int dsu_pmu_device_probe(struct platform_device *pdev)
if (IS_ERR(dsu_pmu))
return PTR_ERR(dsu_pmu);

- rc = dsu_pmu_dt_get_cpus(pdev->dev.of_node, &dsu_pmu->associated_cpus);
+ platform_set_drvdata(pdev, dsu_pmu);
+
+ rc = dsu_pmu_platform_get_cpus(pdev);
if (rc) {
dev_warn(&pdev->dev, "Failed to parse the CPUs\n");
return rc;
@@ -707,7 +756,6 @@ static int dsu_pmu_device_probe(struct platform_device *pdev)
}

dsu_pmu->irq = irq;
- platform_set_drvdata(pdev, dsu_pmu);
rc = cpuhp_state_add_instance(dsu_pmu_cpuhp_state,
&dsu_pmu->cpuhp_node);
if (rc)
@@ -754,11 +802,19 @@ static const struct of_device_id dsu_pmu_of_match[] = {
{ .compatible = "arm,dsu-pmu", },
{},
};
+MODULE_DEVICE_TABLE(of, dsu_pmu_of_match);
+
+static const struct acpi_device_id dsu_pmu_acpi_match[] = {
+ { "ARMHD500", 0},
+ {},
+};
+MODULE_DEVICE_TABLE(acpi, dsu_pmu_acpi_match);

static struct platform_driver dsu_pmu_driver = {
.driver = {
.name = DRVNAME,
.of_match_table = of_match_ptr(dsu_pmu_of_match),
+ .acpi_match_table = ACPI_PTR(dsu_pmu_acpi_match),
},
.probe = dsu_pmu_device_probe,
.remove = dsu_pmu_device_remove,
@@ -827,7 +883,6 @@ static void __exit dsu_pmu_exit(void)
module_init(dsu_pmu_init);
module_exit(dsu_pmu_exit);

-MODULE_DEVICE_TABLE(of, dsu_pmu_of_match);
MODULE_DESCRIPTION("Perf driver for ARM DynamIQ Shared Unit");
MODULE_AUTHOR("Suzuki K Poulose <suzuki.poulose@xxxxxxx>");
MODULE_LICENSE("GPL v2");
--
2.7.4