From: Mark Salter <msalter@xxxxxxxxxx>
In the case of ACPI, the PMU IRQ information is contained in the
MADT table. Also, since the PMU does not exist as a device in the
ACPI DSDT table, it is necessary to create a platform device so
that the appropriate driver probing is triggered.
Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
---
NOTE: Much of the code in pmu_acpi_init() is replaced in a later version
of this patch. The later version of the patch cleans up some of the
possible style/error handling issues that have been pointed out with
this version.
arch/arm64/kernel/smp.c | 5 +++
drivers/perf/Kconfig | 4 ++
drivers/perf/Makefile | 1 +
drivers/perf/arm_pmu_acpi.c | 97 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/perf/arm_pmu.h | 7 ++++
5 files changed, 114 insertions(+)
create mode 100644 drivers/perf/arm_pmu_acpi.c
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 678e084..5c96d23 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -37,6 +37,7 @@
#include <linux/completion.h>
#include <linux/of.h>
#include <linux/irq_work.h>
+#include <linux/perf/arm_pmu.h>
#include <asm/alternative.h>
#include <asm/atomic.h>
@@ -540,6 +541,7 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
return;
}
bootcpu_valid = true;
+ arm_pmu_parse_acpi(0, processor);
return;
}
@@ -560,6 +562,9 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
*/
acpi_set_mailbox_entry(cpu_count, processor);
+ /* get PMU irq info */
+ arm_pmu_parse_acpi(cpu_count, processor);
+
cpu_count++;
}
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 04e2653..818fa3b 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -12,4 +12,8 @@ config ARM_PMU
Say y if you want to use CPU performance monitors on ARM-based
systems.
+config ARM_PMU_ACPI
+ def_bool y
+ depends on ARM_PMU && ACPI
+
endmenu
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index acd2397..fd8090d 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_ARM_PMU) += arm_pmu.o
+obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
new file mode 100644
index 0000000..98c452d
--- /dev/null
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -0,0 +1,97 @@
+/*
+ * PMU support
+ *
+ * Copyright (C) 2015 Red Hat Inc.
+ * Author: Mark Salter <msalter@xxxxxxxxxx>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include <linux/perf/arm_pmu.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+
+#define PMU_PDEV_NAME "armv8-pmu"
+
+struct pmu_irq {
+ int gsi;
+ int trigger;
+};
+
+static struct pmu_irq pmu_irqs[NR_CPUS] __initdata;
+
+void __init arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic)
+{
+ pmu_irqs[cpu].gsi = gic->performance_interrupt;
+ if (gic->flags & ACPI_MADT_PERFORMANCE_IRQ_MODE)
+ pmu_irqs[cpu].trigger = ACPI_EDGE_SENSITIVE;
+ else
+ pmu_irqs[cpu].trigger = ACPI_LEVEL_SENSITIVE;
+}
+
+static int __init pmu_acpi_init(void)
+{
+ struct platform_device *pdev;
+ struct pmu_irq *pirq = pmu_irqs;
+ struct resource *res, *r;
+ int err = -ENOMEM;
+ int i, count, irq;
+
+ if (acpi_disabled)
+ return 0;
+
+ /* Must have irq for boot boot cpu, at least */
+ if (pirq->gsi == 0)
+ return -EINVAL;
+
+ irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
+ ACPI_ACTIVE_HIGH);
+
+ if (irq_is_percpu(irq))
+ count = 1;
+ else
+ for (i = 1, count = 1; i < NR_CPUS; i++)
+ if (pmu_irqs[i].gsi)
+ ++count;
+
+ pdev = platform_device_alloc(PMU_PDEV_NAME, -1);
+ if (!pdev)
+ goto err_free_gsi;
+
+ res = kcalloc(count, sizeof(*res), GFP_KERNEL);
+ if (!res)
+ goto err_free_device;
+
+ for (i = 0, r = res; i < count; i++, pirq++, r++) {
+ if (i)
+ irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
+ ACPI_ACTIVE_HIGH);
+ r->start = r->end = irq;
+ r->flags = IORESOURCE_IRQ;
+ if (pirq->trigger == ACPI_EDGE_SENSITIVE)
+ r->flags |= IORESOURCE_IRQ_HIGHEDGE;
+ else
+ r->flags |= IORESOURCE_IRQ_HIGHLEVEL;
+ }
+
+ err = platform_device_add_resources(pdev, res, count);
+ if (!err)
+ err = platform_device_add(pdev);
+ kfree(res);
+ if (!err)
+ return 0;
+
+err_free_device:
+ platform_device_put(pdev);
+
+err_free_gsi:
+ for (i = 0; i < count; i++)
+ acpi_unregister_gsi(pmu_irqs[i].gsi);
+
+ return err;
+}
+arch_initcall(pmu_acpi_init);
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 7e814fe..9ed9fdc 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -156,4 +156,11 @@ int arm_pmu_device_probe(struct platform_device *pdev,
#endif /* CONFIG_ARM_PMU */
+#ifdef CONFIG_ARM_PMU_ACPI
+struct acpi_madt_generic_interrupt;
+void arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic);
+#else
+#define arm_pmu_parse_acpi(a, b) do { } while (0)
+#endif /* CONFIG_ARM_PMU_ACPI */
+
#endif /* __ARM_PMU_H__ */
--
2.5.5
--
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