diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/perf/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/perf/Makefile | 1 | ||||
| -rw-r--r-- | drivers/perf/arm_pmu.c | 4 | ||||
| -rw-r--r-- | drivers/perf/arm_pmu_acpi.c | 256 |
4 files changed, 263 insertions, 2 deletions
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig index c436e0d303e7..aa587edaf9ea 100644 --- a/drivers/perf/Kconfig +++ b/drivers/perf/Kconfig @@ -12,6 +12,10 @@ config ARM_PMU Say y if you want to use CPU performance monitors on ARM-based systems. +config ARM_PMU_ACPI + depends on ARM_PMU && ACPI + def_bool y + config QCOM_L2_PMU bool "Qualcomm Technologies L2-cache PMU" depends on ARCH_QCOM && ARM64 && PERF_EVENTS && ACPI diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile index 925cd3903029..6420bd4394d5 100644 --- a/drivers/perf/Makefile +++ b/drivers/perf/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_ARM_PMU) += arm_pmu.o arm_pmu_platform.o +obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o obj-$(CONFIG_QCOM_L2_PMU) += qcom_l2_pmu.o obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index b3bedfa512eb..dc459eb1246b 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -525,7 +525,7 @@ int perf_num_counters(void) } EXPORT_SYMBOL_GPL(perf_num_counters); -static void armpmu_free_irq(struct arm_pmu *armpmu, int cpu) +void armpmu_free_irq(struct arm_pmu *armpmu, int cpu) { struct pmu_hw_events __percpu *hw_events = armpmu->hw_events; int irq = per_cpu(hw_events->irq, cpu); @@ -550,7 +550,7 @@ void armpmu_free_irqs(struct arm_pmu *armpmu) armpmu_free_irq(armpmu, cpu); } -static int armpmu_request_irq(struct arm_pmu *armpmu, int cpu) +int armpmu_request_irq(struct arm_pmu *armpmu, int cpu) { int err = 0; struct pmu_hw_events __percpu *hw_events = armpmu->hw_events; diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c new file mode 100644 index 000000000000..34c862f213c7 --- /dev/null +++ b/drivers/perf/arm_pmu_acpi.c @@ -0,0 +1,256 @@ +/* + * ACPI probing code for ARM performance counters. + * + * Copyright (C) 2017 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/acpi.h> +#include <linux/cpumask.h> +#include <linux/init.h> +#include <linux/percpu.h> +#include <linux/perf/arm_pmu.h> + +#include <asm/cputype.h> + +static DEFINE_PER_CPU(struct arm_pmu *, probed_pmus); +static DEFINE_PER_CPU(int, pmu_irqs); + +static int arm_pmu_acpi_register_irq(int cpu) +{ + struct acpi_madt_generic_interrupt *gicc; + int gsi, trigger; + + gicc = acpi_cpu_get_madt_gicc(cpu); + if (WARN_ON(!gicc)) + return -EINVAL; + + gsi = gicc->performance_interrupt; + if (gicc->flags & ACPI_MADT_PERFORMANCE_IRQ_MODE) + trigger = ACPI_EDGE_SENSITIVE; + else + trigger = ACPI_LEVEL_SENSITIVE; + + /* + * Helpfully, the MADT GICC doesn't have a polarity flag for the + * "performance interrupt". Luckily, on compliant GICs the polarity is + * a fixed value in HW (for both SPIs and PPIs) that we cannot change + * from SW. + * + * Here we pass in ACPI_ACTIVE_HIGH to keep the core code happy. This + * may not match the real polarity, but that should not matter. + * + * Other interrupt controllers are not supported with ACPI. + */ + return acpi_register_gsi(NULL, gsi, trigger, ACPI_ACTIVE_HIGH); +} + +static void arm_pmu_acpi_unregister_irq(int cpu) +{ + struct acpi_madt_generic_interrupt *gicc; + int gsi; + + gicc = acpi_cpu_get_madt_gicc(cpu); + if (!gicc) + return; + + gsi = gicc->performance_interrupt; + acpi_unregister_gsi(gsi); +} + +static int arm_pmu_acpi_parse_irqs(void) +{ + int irq, cpu, irq_cpu, err; + + for_each_possible_cpu(cpu) { + irq = arm_pmu_acpi_register_irq(cpu); + if (irq < 0) { + err = irq; + pr_warn("Unable to parse ACPI PMU IRQ for CPU%d: %d\n", + cpu, err); + goto out_err; + } else if (irq == 0) { + pr_warn("No ACPI PMU IRQ for CPU%d\n", cpu); + } + + per_cpu(pmu_irqs, cpu) = irq; + } + + return 0; + +out_err: + for_each_possible_cpu(cpu) { + irq = per_cpu(pmu_irqs, cpu); + if (!irq) + continue; + + arm_pmu_acpi_unregister_irq(cpu); + + /* + * Blat all copies of the IRQ so that we only unregister the + * corresponding GSI once (e.g. when we have PPIs). + */ + for_each_possible_cpu(irq_cpu) { + if (per_cpu(pmu_irqs, irq_cpu) == irq) + per_cpu(pmu_irqs, irq_cpu) = 0; + } + } + + return err; +} + +static struct arm_pmu *arm_pmu_acpi_find_alloc_pmu(void) +{ + unsigned long cpuid = read_cpuid_id(); + struct arm_pmu *pmu; + int cpu; + + for_each_possible_cpu(cpu) { + pmu = per_cpu(probed_pmus, cpu); + if (!pmu || pmu->acpi_cpuid != cpuid) + continue; + + return pmu; + } + + pmu = armpmu_alloc(); + if (!pmu) { + pr_warn("Unable to allocate PMU for CPU%d\n", + smp_processor_id()); + return NULL; + } + + pmu->acpi_cpuid = cpuid; + + return pmu; +} + +/* + * This must run before the common arm_pmu hotplug logic, so that we can + * associate a CPU and its interrupt before the common code tries to manage the + * affinity and so on. + * + * Note that hotplug events are serialized, so we cannot race with another CPU + * coming up. The perf core won't open events while a hotplug event is in + * progress. + */ +static int arm_pmu_acpi_cpu_starting(unsigned int cpu) +{ + struct arm_pmu *pmu; + struct pmu_hw_events __percpu *hw_events; + int irq; + + /* If we've already probed this CPU, we have nothing to do */ + if (per_cpu(probed_pmus, cpu)) + return 0; + + irq = per_cpu(pmu_irqs, cpu); + + pmu = arm_pmu_acpi_find_alloc_pmu(); + if (!pmu) + return -ENOMEM; + + cpumask_set_cpu(cpu, &pmu->supported_cpus); + + per_cpu(probed_pmus, cpu) = pmu; + + /* + * Log and request the IRQ so the core arm_pmu code can manage it. In + * some situations (e.g. mismatched PPIs), we may fail to request the + * IRQ. However, it may be too late for us to do anything about it. + * The common ARM PMU code will log a warning in this case. + */ + hw_events = pmu->hw_events; + per_cpu(hw_events->irq, cpu) = irq; + armpmu_request_irq(pmu, cpu); + + /* + * Ideally, we'd probe the PMU here when we find the first matching + * CPU. We can't do that for several reasons; see the comment in + * arm_pmu_acpi_init(). + * + * So for the time being, we're done. + */ + return 0; +} + +int arm_pmu_acpi_probe(armpmu_init_fn init_fn) +{ + int pmu_idx = 0; + int cpu, ret; + + if (acpi_disabled) + return 0; + + /* + * Initialise and register the set of PMUs which we know about right + * now. Ideally we'd do this in arm_pmu_acpi_cpu_starting() so that we + * could handle late hotplug, but this may lead to deadlock since we + * might try to register a hotplug notifier instance from within a + * hotplug notifier. + * + * There's also the problem of having access to the right init_fn, + * without tying this too deeply into the "real" PMU driver. + * + * For the moment, as with the platform/DT case, we need at least one + * of a PMU's CPUs to be online at probe time. + */ + for_each_possible_cpu(cpu) { + struct arm_pmu *pmu = per_cpu(probed_pmus, cpu); + char *base_name; + + if (!pmu || pmu->name) + continue; + + ret = init_fn(pmu); + if (ret == -ENODEV) { + /* PMU not handled by this driver, or not present */ + continue; + } else if (ret) { + pr_warn("Unable to initialise PMU for CPU%d\n", cpu); + return ret; + } + + base_name = pmu->name; + pmu->name = kasprintf(GFP_KERNEL, "%s_%d", base_name, pmu_idx++); + if (!pmu->name) { + pr_warn("Unable to allocate PMU name for CPU%d\n", cpu); + return -ENOMEM; + } + + ret = armpmu_register(pmu); + if (ret) { + pr_warn("Failed to register PMU for CPU%d\n", cpu); + return ret; + } + } + + return 0; +} + +static int arm_pmu_acpi_init(void) +{ + int ret; + + if (acpi_disabled) + return 0; + + /* + * We can't request IRQs yet, since we don't know the cookie value + * until we know which CPUs share the same logical PMU. We'll handle + * that in arm_pmu_acpi_cpu_starting(). + */ + ret = arm_pmu_acpi_parse_irqs(); + if (ret) + return ret; + + ret = cpuhp_setup_state(CPUHP_AP_PERF_ARM_ACPI_STARTING, + "perf/arm/pmu_acpi:starting", + arm_pmu_acpi_cpu_starting, NULL); + + return ret; +} +subsys_initcall(arm_pmu_acpi_init) |