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authorMark Rutland <mark.rutland@arm.com>2017-04-11 09:39:53 +0100
committerWill Deacon <will.deacon@arm.com>2017-04-11 16:29:54 +0100
commit18bfcfe51b8f60b69ab012888dea8061a9cd3381 (patch)
tree1b24520d4c02227265176bcb2a559baa84c862ef /drivers/perf/arm_pmu_platform.c
parent3cf7ee98b8489fd2ff58374e3882a666f81d629f (diff)
drivers/perf: arm_pmu: split out platform device probe logic
Now that we've split the pdev and DT probing logic from the runtime management, let's move the former into its own file. We gain a few lines due to the copyright header and includes, but this should keep the logic clearly separated, and paves the way for adding ACPI support in a similar fashion. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Jeremy Linton <jeremy.linton@arm.com> [will: rename nr_irqs to avoid conflict with global variable] Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/perf/arm_pmu_platform.c')
-rw-r--r--drivers/perf/arm_pmu_platform.c235
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c
new file mode 100644
index 000000000000..69255f53057a
--- /dev/null
+++ b/drivers/perf/arm_pmu_platform.c
@@ -0,0 +1,235 @@
+/*
+ * platform_device probing code for ARM performance counters.
+ *
+ * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
+ * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com>
+ */
+#define pr_fmt(fmt) "hw perfevents: " fmt
+
+#include <linux/bug.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+#include <linux/kconfig.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/percpu.h>
+#include <linux/perf/arm_pmu.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+static int probe_current_pmu(struct arm_pmu *pmu,
+ const struct pmu_probe_info *info)
+{
+ int cpu = get_cpu();
+ unsigned int cpuid = read_cpuid_id();
+ int ret = -ENODEV;
+
+ pr_info("probing PMU on CPU %d\n", cpu);
+
+ for (; info->init != NULL; info++) {
+ if ((cpuid & info->mask) != info->cpuid)
+ continue;
+ ret = info->init(pmu);
+ break;
+ }
+
+ put_cpu();
+ return ret;
+}
+
+static int pmu_parse_percpu_irq(struct arm_pmu *pmu, int irq)
+{
+ int cpu, ret;
+ struct pmu_hw_events __percpu *hw_events = pmu->hw_events;
+
+ ret = irq_get_percpu_devid_partition(irq, &pmu->supported_cpus);
+ if (ret)
+ return ret;
+
+ for_each_cpu(cpu, &pmu->supported_cpus)
+ per_cpu(hw_events->irq, cpu) = irq;
+
+ return 0;
+}
+
+static bool pmu_has_irq_affinity(struct device_node *node)
+{
+ return !!of_find_property(node, "interrupt-affinity", NULL);
+}
+
+static int pmu_parse_irq_affinity(struct device_node *node, int i)
+{
+ struct device_node *dn;
+ int cpu;
+
+ /*
+ * If we don't have an interrupt-affinity property, we guess irq
+ * affinity matches our logical CPU order, as we used to assume.
+ * This is fragile, so we'll warn in pmu_parse_irqs().
+ */
+ if (!pmu_has_irq_affinity(node))
+ return i;
+
+ dn = of_parse_phandle(node, "interrupt-affinity", i);
+ if (!dn) {
+ pr_warn("failed to parse interrupt-affinity[%d] for %s\n",
+ i, node->name);
+ return -EINVAL;
+ }
+
+ /* Now look up the logical CPU number */
+ for_each_possible_cpu(cpu) {
+ struct device_node *cpu_dn;
+
+ cpu_dn = of_cpu_device_node_get(cpu);
+ of_node_put(cpu_dn);
+
+ if (dn == cpu_dn)
+ break;
+ }
+
+ if (cpu >= nr_cpu_ids) {
+ pr_warn("failed to find logical CPU for %s\n", dn->name);
+ }
+
+ of_node_put(dn);
+
+ return cpu;
+}
+
+static int pmu_parse_irqs(struct arm_pmu *pmu)
+{
+ int i = 0, num_irqs;
+ struct platform_device *pdev = pmu->plat_device;
+ struct pmu_hw_events __percpu *hw_events = pmu->hw_events;
+
+ num_irqs = platform_irq_count(pdev);
+ if (num_irqs < 0) {
+ pr_err("unable to count PMU IRQs\n");
+ return num_irqs;
+ }
+
+ /*
+ * In this case we have no idea which CPUs are covered by the PMU.
+ * To match our prior behaviour, we assume all CPUs in this case.
+ */
+ if (num_irqs == 0) {
+ pr_warn("no irqs for PMU, sampling events not supported\n");
+ pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+ cpumask_setall(&pmu->supported_cpus);
+ return 0;
+ }
+
+ if (num_irqs == 1) {
+ int irq = platform_get_irq(pdev, 0);
+ if (irq && irq_is_percpu(irq))
+ return pmu_parse_percpu_irq(pmu, irq);
+ }
+
+ if (!pmu_has_irq_affinity(pdev->dev.of_node)) {
+ pr_warn("no interrupt-affinity property for %s, guessing.\n",
+ of_node_full_name(pdev->dev.of_node));
+ }
+
+ /*
+ * Some platforms have all PMU IRQs OR'd into a single IRQ, with a
+ * special platdata function that attempts to demux them.
+ */
+ if (dev_get_platdata(&pdev->dev))
+ cpumask_setall(&pmu->supported_cpus);
+
+ for (i = 0; i < num_irqs; i++) {
+ int cpu, irq;
+
+ irq = platform_get_irq(pdev, i);
+ if (WARN_ON(irq <= 0))
+ continue;
+
+ if (irq_is_percpu(irq)) {
+ pr_warn("multiple PPIs or mismatched SPI/PPI detected\n");
+ return -EINVAL;
+ }
+
+ cpu = pmu_parse_irq_affinity(pdev->dev.of_node, i);
+ if (cpu < 0)
+ return cpu;
+ if (cpu >= nr_cpu_ids)
+ continue;
+
+ if (per_cpu(hw_events->irq, cpu)) {
+ pr_warn("multiple PMU IRQs for the same CPU detected\n");
+ return -EINVAL;
+ }
+
+ per_cpu(hw_events->irq, cpu) = irq;
+ cpumask_set_cpu(cpu, &pmu->supported_cpus);
+ }
+
+ return 0;
+}
+
+int arm_pmu_device_probe(struct platform_device *pdev,
+ const struct of_device_id *of_table,
+ const struct pmu_probe_info *probe_table)
+{
+ const struct of_device_id *of_id;
+ armpmu_init_fn init_fn;
+ struct device_node *node = pdev->dev.of_node;
+ struct arm_pmu *pmu;
+ int ret = -ENODEV;
+
+ pmu = armpmu_alloc();
+ if (!pmu)
+ return -ENOMEM;
+
+ pmu->plat_device = pdev;
+
+ ret = pmu_parse_irqs(pmu);
+ if (ret)
+ goto out_free;
+
+ if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) {
+ init_fn = of_id->data;
+
+ pmu->secure_access = of_property_read_bool(pdev->dev.of_node,
+ "secure-reg-access");
+
+ /* arm64 systems boot only as non-secure */
+ if (IS_ENABLED(CONFIG_ARM64) && pmu->secure_access) {
+ pr_warn("ignoring \"secure-reg-access\" property for arm64\n");
+ pmu->secure_access = false;
+ }
+
+ ret = init_fn(pmu);
+ } else if (probe_table) {
+ cpumask_setall(&pmu->supported_cpus);
+ ret = probe_current_pmu(pmu, probe_table);
+ }
+
+ if (ret) {
+ pr_info("%s: failed to probe PMU!\n", of_node_full_name(node));
+ goto out_free;
+ }
+
+ ret = armpmu_request_irqs(pmu);
+ if (ret)
+ goto out_free_irqs;
+
+ ret = armpmu_register(pmu);
+ if (ret)
+ goto out_free;
+
+ return 0;
+
+out_free_irqs:
+ armpmu_free_irqs(pmu);
+out_free:
+ pr_info("%s: failed to register PMU devices!\n",
+ of_node_full_name(node));
+ armpmu_free(pmu);
+ return ret;
+}

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