perf/arm_cspmu: Add devicetree support

Hook up devicetree probing support. For now let's hope that people
implement PMIIDR properly and we don't need an override property or
match data mechanism.

Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Besar Wicaksono <bwicaksono@nvidia.com>
Tested-by: Besar Wicaksono <bwicaksono@nvidia.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/836722034302ff62f2df56aaeb0036e71945a5d1.1706718007.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
index 5919ef63c2a87c8eabd461dd5660962229e5c714..b9a252272f1e9f596db7aeba99f4d28dd6b95f84 100644 (file)
--- a/drivers/perf/arm_cspmu/arm_cspmu.c
+++ b/drivers/perf/arm_cspmu/arm_cspmu.c
@@ -27,6 +27,7 @@
 #include <linux/io-64-nonatomic-lo-hi.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/of.h>
 #include <linux/perf_event.h>
 #include <linux/platform_device.h>
 
@@ -114,7 +115,9 @@ static void arm_cspmu_set_ev_filter(struct arm_cspmu *cspmu,
 
 static struct acpi_apmt_node *arm_cspmu_apmt_node(struct device *dev)
 {
-       return *(struct acpi_apmt_node **)dev_get_platdata(dev);
+       struct acpi_apmt_node **ptr = dev_get_platdata(dev);
+
+       return ptr ? *ptr : NULL;
 }
 
 /*
@@ -310,6 +313,10 @@ static const char *arm_cspmu_get_name(const struct arm_cspmu *cspmu)
 
        dev = cspmu->dev;
        apmt_node = arm_cspmu_apmt_node(dev);
+       if (!apmt_node)
+               return devm_kasprintf(dev, GFP_KERNEL, PMUNAME "_%u",
+                                     atomic_fetch_inc(&pmu_idx[0]));
+
        pmu_type = apmt_node->type;
 
        if (pmu_type >= ACPI_APMT_NODE_TYPE_COUNT) {
@@ -425,7 +432,7 @@ static int arm_cspmu_init_impl_ops(struct arm_cspmu *cspmu)
        };
 
        /* Firmware may override implementer/product ID from PMIIDR */
-       if (apmt_node->impl_id)
+       if (apmt_node && apmt_node->impl_id)
                cspmu->impl.pmiidr = apmt_node->impl_id;
 
        /* Find implementer specific attribute ops. */
@@ -940,7 +947,14 @@ static struct arm_cspmu *arm_cspmu_alloc(struct platform_device *pdev)
        platform_set_drvdata(pdev, cspmu);
 
        apmt_node = arm_cspmu_apmt_node(dev);
-       cspmu->has_atomic_dword = apmt_node->flags & ACPI_APMT_FLAGS_ATOMIC;
+       if (apmt_node) {
+               cspmu->has_atomic_dword = apmt_node->flags & ACPI_APMT_FLAGS_ATOMIC;
+       } else {
+               u32 width = 0;
+
+               device_property_read_u32(dev, "reg-io-width", &width);
+               cspmu->has_atomic_dword = (width == 8);
+       }
 
        return cspmu;
 }
@@ -1131,11 +1145,6 @@ static int arm_cspmu_acpi_get_cpus(struct arm_cspmu *cspmu)
                }
        }
 
-       if (cpumask_empty(&cspmu->associated_cpus)) {
-               dev_dbg(cspmu->dev, "No cpu associated with the PMU\n");
-               return -ENODEV;
-       }
-
        return 0;
 }
 #else
@@ -1145,9 +1154,36 @@ static int arm_cspmu_acpi_get_cpus(struct arm_cspmu *cspmu)
 }
 #endif
 
+static int arm_cspmu_of_get_cpus(struct arm_cspmu *cspmu)
+{
+       struct of_phandle_iterator it;
+       int ret, cpu;
+
+       of_for_each_phandle(&it, ret, dev_of_node(cspmu->dev), "cpus", NULL, 0) {
+               cpu = of_cpu_node_to_id(it.node);
+               if (cpu < 0)
+                       continue;
+               cpumask_set_cpu(cpu, &cspmu->associated_cpus);
+       }
+       return ret == -ENOENT ? 0 : ret;
+}
+
 static int arm_cspmu_get_cpus(struct arm_cspmu *cspmu)
 {
-       return arm_cspmu_acpi_get_cpus(cspmu);
+       int ret = 0;
+
+       if (arm_cspmu_apmt_node(cspmu->dev))
+               ret = arm_cspmu_acpi_get_cpus(cspmu);
+       else if (device_property_present(cspmu->dev, "cpus"))
+               ret = arm_cspmu_of_get_cpus(cspmu);
+       else
+               cpumask_copy(&cspmu->associated_cpus, cpu_possible_mask);
+
+       if (!ret && cpumask_empty(&cspmu->associated_cpus)) {
+               dev_dbg(cspmu->dev, "No cpu associated with the PMU\n");
+               ret = -ENODEV;
+       }
+       return ret;
 }
 
 static int arm_cspmu_register_pmu(struct arm_cspmu *cspmu)
@@ -1242,11 +1278,18 @@ static const struct platform_device_id arm_cspmu_id[] = {
 };
 MODULE_DEVICE_TABLE(platform, arm_cspmu_id);
 
+static const struct of_device_id arm_cspmu_of_match[] = {
+       { .compatible = "arm,coresight-pmu" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, arm_cspmu_of_match);
+
 static struct platform_driver arm_cspmu_driver = {
        .driver = {
-                       .name = DRVNAME,
-                       .suppress_bind_attrs = true,
-               },
+               .name = DRVNAME,
+               .of_match_table = arm_cspmu_of_match,
+               .suppress_bind_attrs = true,
+       },
        .probe = arm_cspmu_device_probe,
        .remove_new = arm_cspmu_device_remove,
        .id_table = arm_cspmu_id,