[PATCH 3/8] arm64: pmu: Add support for probing with ACPI
From: Jeremy Linton <hidden>
Date: 2016-06-09 22:23:28
Also in:
linux-acpi
Subsystem:
arm pmu profiling and debugging, arm64 port (aarch64 architecture), the rest · Maintainers:
Will Deacon, Mark Rutland, Catalin Marinas, Linus Torvalds
From: Mark Salter <redacted>
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 <redacted>
Signed-off-by: Jeremy Linton <redacted>
---
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@redhat.com> + * + * 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