From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/perf/arm_pmu_acpi.c | 360 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 360 insertions(+) create mode 100644 drivers/perf/arm_pmu_acpi.c (limited to 'drivers/perf/arm_pmu_acpi.c') diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c new file mode 100644 index 000000000..96ffadd65 --- /dev/null +++ b/drivers/perf/arm_pmu_acpi.c @@ -0,0 +1,360 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ACPI probing code for ARM performance counters. + * + * Copyright (C) 2017 ARM Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include + +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); + + gsi = gicc->performance_interrupt; + + /* + * Per the ACPI spec, the MADT cannot describe a PMU that doesn't + * have an interrupt. QEMU advertises this by using a GSI of zero, + * which is not known to be valid on any hardware despite being + * valid per the spec. Take the pragmatic approach and reject a + * GSI of zero for now. + */ + if (!gsi) + return 0; + + 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); + + gsi = gicc->performance_interrupt; + if (gsi) + acpi_unregister_gsi(gsi); +} + +#if IS_ENABLED(CONFIG_ARM_SPE_PMU) +static struct resource spe_resources[] = { + { + /* irq */ + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device spe_dev = { + .name = ARMV8_SPE_PDEV_NAME, + .id = -1, + .resource = spe_resources, + .num_resources = ARRAY_SIZE(spe_resources) +}; + +/* + * For lack of a better place, hook the normal PMU MADT walk + * and create a SPE device if we detect a recent MADT with + * a homogeneous PPI mapping. + */ +static void arm_spe_acpi_register_device(void) +{ + int cpu, hetid, irq, ret; + bool first = true; + u16 gsi = 0; + + /* + * Sanity check all the GICC tables for the same interrupt number. + * For now, we only support homogeneous ACPI/SPE machines. + */ + for_each_possible_cpu(cpu) { + struct acpi_madt_generic_interrupt *gicc; + + gicc = acpi_cpu_get_madt_gicc(cpu); + if (gicc->header.length < ACPI_MADT_GICC_SPE) + return; + + if (first) { + gsi = gicc->spe_interrupt; + if (!gsi) + return; + hetid = find_acpi_cpu_topology_hetero_id(cpu); + first = false; + } else if ((gsi != gicc->spe_interrupt) || + (hetid != find_acpi_cpu_topology_hetero_id(cpu))) { + pr_warn("ACPI: SPE must be homogeneous\n"); + return; + } + } + + irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, + ACPI_ACTIVE_HIGH); + if (irq < 0) { + pr_warn("ACPI: SPE Unable to register interrupt: %d\n", gsi); + return; + } + + spe_resources[0].start = irq; + ret = platform_device_register(&spe_dev); + if (ret < 0) { + pr_warn("ACPI: SPE: Unable to register device\n"); + acpi_unregister_gsi(gsi); + } +} +#else +static inline void arm_spe_acpi_register_device(void) +{ +} +#endif /* CONFIG_ARM_SPE_PMU */ + +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); + } + + /* + * Log and request the IRQ so the core arm_pmu code can manage + * it. We'll have to sanity-check IRQs later when we associate + * them with their PMUs. + */ + per_cpu(pmu_irqs, cpu) = irq; + err = armpmu_request_irq(irq, cpu); + if (err) + goto out_err; + } + + 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_atomic(); + if (!pmu) { + pr_warn("Unable to allocate PMU for CPU%d\n", + smp_processor_id()); + return NULL; + } + + pmu->acpi_cpuid = cpuid; + + return pmu; +} + +/* + * Check whether the new IRQ is compatible with those already associated with + * the PMU (e.g. we don't have mismatched PPIs). + */ +static bool pmu_irq_matches(struct arm_pmu *pmu, int irq) +{ + struct pmu_hw_events __percpu *hw_events = pmu->hw_events; + int cpu; + + if (!irq) + return true; + + for_each_cpu(cpu, &pmu->supported_cpus) { + int other_irq = per_cpu(hw_events->irq, cpu); + if (!other_irq) + continue; + + if (irq == other_irq) + continue; + if (!irq_is_percpu_devid(irq) && !irq_is_percpu_devid(other_irq)) + continue; + + pr_warn("mismatched PPIs detected\n"); + return false; + } + + return true; +} + +/* + * 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; + + per_cpu(probed_pmus, cpu) = pmu; + + if (pmu_irq_matches(pmu, irq)) { + hw_events = pmu->hw_events; + per_cpu(hw_events->irq, cpu) = irq; + } + + cpumask_set_cpu(cpu, &pmu->supported_cpus); + + /* + * 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; + + /* + * 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); + kfree(pmu->name); + return ret; + } + } + + return 0; +} + +static int arm_pmu_acpi_init(void) +{ + int ret; + + if (acpi_disabled) + return 0; + + arm_spe_acpi_register_device(); + + 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) -- cgit v1.2.3