diff options
| -rw-r--r-- | arch/arm/include/asm/pmu.h | 29 | ||||
| -rw-r--r-- | arch/arm/kernel/perf_event.c | 74 | ||||
| -rw-r--r-- | arch/arm/kernel/pmu.c | 182 |
3 files changed, 80 insertions, 205 deletions
diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h index b7e82c4aced..a06ba8773cd 100644 --- a/arch/arm/include/asm/pmu.h +++ b/arch/arm/include/asm/pmu.h @@ -14,6 +14,10 @@ #include <linux/interrupt.h> +/* + * Types of PMUs that can be accessed directly and require mutual + * exclusion between profiling tools. + */ enum arm_pmu_type { ARM_PMU_DEVICE_CPU = 0, ARM_NUM_PMU_DEVICES, @@ -37,21 +41,17 @@ struct arm_pmu_platdata { * reserve_pmu() - reserve the hardware performance counters * * Reserve the hardware performance counters in the system for exclusive use. - * The platform_device for the system is returned on success, ERR_PTR() - * encoded error on failure. + * Returns 0 on success or -EBUSY if the lock is already held. */ -extern struct platform_device * +extern int reserve_pmu(enum arm_pmu_type type); /** * release_pmu() - Relinquish control of the performance counters * * Release the performance counters and allow someone else to use them. - * Callers must have disabled the counters and released IRQs before calling - * this. The platform_device returned from reserve_pmu() must be passed as - * a cookie. */ -extern int +extern void release_pmu(enum arm_pmu_type type); /** @@ -68,23 +68,14 @@ init_pmu(enum arm_pmu_type type); #include <linux/err.h> -static inline struct platform_device * -reserve_pmu(enum arm_pmu_type type) -{ - return ERR_PTR(-ENODEV); -} - static inline int -release_pmu(enum arm_pmu_type type) +reserve_pmu(enum arm_pmu_type type) { return -ENODEV; } -static inline int -init_pmu(enum arm_pmu_type type) -{ - return -ENODEV; -} +static inline void +release_pmu(enum arm_pmu_type type) { } #endif /* CONFIG_CPU_HAS_PMU */ diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 73049963bf4..8514855ffc2 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -393,15 +393,15 @@ armpmu_reserve_hardware(void) { struct arm_pmu_platdata *plat; irq_handler_t handle_irq; - int i, err = -ENODEV, irq; + int i, err, irq, irqs; - pmu_device = reserve_pmu(ARM_PMU_DEVICE_CPU); - if (IS_ERR(pmu_device)) { + err = reserve_pmu(ARM_PMU_DEVICE_CPU); + if (err) { pr_warning("unable to reserve pmu\n"); - return PTR_ERR(pmu_device); + return err; } - init_pmu(ARM_PMU_DEVICE_CPU); + irqs = pmu_device->num_resources; plat = dev_get_platdata(&pmu_device->dev); if (plat && plat->handle_irq) @@ -409,22 +409,34 @@ armpmu_reserve_hardware(void) else handle_irq = armpmu->handle_irq; - if (pmu_device->num_resources < 1) { + if (irqs < 1) { pr_err("no irqs for PMUs defined\n"); return -ENODEV; } - for (i = 0; i < pmu_device->num_resources; ++i) { + for (i = 0; i < irqs; ++i) { irq = platform_get_irq(pmu_device, i); if (irq < 0) continue; + /* + * If we have a single PMU interrupt that we can't shift, + * assume that we're running on a uniprocessor machine and + * continue. + */ + err = irq_set_affinity(irq, cpumask_of(i)); + if (err && irqs > 1) { + pr_err("unable to set irq affinity (irq=%d, cpu=%u)\n", + irq, i); + break; + } + err = request_irq(irq, handle_irq, IRQF_DISABLED | IRQF_NOBALANCING, - "armpmu", NULL); + "arm-pmu", NULL); if (err) { - pr_warning("unable to request IRQ%d for ARM perf " - "counters\n", irq); + pr_err("unable to request IRQ%d for ARM PMU counters\n", + irq); break; } } @@ -436,7 +448,6 @@ armpmu_reserve_hardware(void) free_irq(irq, NULL); } release_pmu(ARM_PMU_DEVICE_CPU); - pmu_device = NULL; } return err; @@ -455,7 +466,6 @@ armpmu_release_hardware(void) armpmu->stop(); release_pmu(ARM_PMU_DEVICE_CPU); - pmu_device = NULL; } static atomic_t active_events = ATOMIC_INIT(0); @@ -638,6 +648,46 @@ armpmu_reset(void) } arch_initcall(armpmu_reset); +/* + * PMU platform driver and devicetree bindings. + */ +static struct of_device_id armpmu_of_device_ids[] = { + {.compatible = "arm,cortex-a9-pmu"}, + {.compatible = "arm,cortex-a8-pmu"}, + {.compatible = "arm,arm1136-pmu"}, + {.compatible = "arm,arm1176-pmu"}, + {}, +}; + +static struct platform_device_id armpmu_plat_device_ids[] = { + {.name = "arm-pmu"}, + {}, +}; + +static int __devinit armpmu_device_probe(struct platform_device *pdev) +{ + pmu_device = pdev; + return 0; +} + +static struct platform_driver armpmu_driver = { + .driver = { + .name = "arm-pmu", + .of_match_table = armpmu_of_device_ids, + }, + .probe = armpmu_device_probe, + .id_table = armpmu_plat_device_ids, +}; + +static int __init register_pmu_driver(void) +{ + return platform_driver_register(&armpmu_driver); +} +device_initcall(register_pmu_driver); + +/* + * CPU PMU identification and registration. + */ static int __init init_hw_perf_events(void) { diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c index c53474fe84d..2c3407ee857 100644 --- a/arch/arm/kernel/pmu.c +++ b/arch/arm/kernel/pmu.c @@ -10,192 +10,26 @@ * */ -#define pr_fmt(fmt) "PMU: " fmt - -#include <linux/cpumask.h> #include <linux/err.h> -#include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/module.h> -#include <linux/of_device.h> -#include <linux/platform_device.h> #include <asm/pmu.h> -static volatile long pmu_lock; - -static struct platform_device *pmu_devices[ARM_NUM_PMU_DEVICES]; - -static int __devinit pmu_register(struct platform_device *pdev, - enum arm_pmu_type type) -{ - if (type < 0 || type >= ARM_NUM_PMU_DEVICES) { - pr_warning("received registration request for unknown " - "PMU device type %d\n", type); - return -EINVAL; - } - - if (pmu_devices[type]) { - pr_warning("rejecting duplicate registration of PMU device " - "type %d.", type); - return -ENOSPC; - } - - pr_info("registered new PMU device of type %d\n", type); - pmu_devices[type] = pdev; - return 0; -} - -#define OF_MATCH_PMU(_name, _type) { \ - .compatible = _name, \ - .data = (void *)_type, \ -} - -#define OF_MATCH_CPU(name) OF_MATCH_PMU(name, ARM_PMU_DEVICE_CPU) - -static struct of_device_id armpmu_of_device_ids[] = { - OF_MATCH_CPU("arm,cortex-a9-pmu"), - OF_MATCH_CPU("arm,cortex-a8-pmu"), - OF_MATCH_CPU("arm,arm1136-pmu"), - OF_MATCH_CPU("arm,arm1176-pmu"), - {}, -}; - -#define PLAT_MATCH_PMU(_name, _type) { \ - .name = _name, \ - .driver_data = _type, \ -} - -#define PLAT_MATCH_CPU(_name) PLAT_MATCH_PMU(_name, ARM_PMU_DEVICE_CPU) - -static struct platform_device_id armpmu_plat_device_ids[] = { - PLAT_MATCH_CPU("arm-pmu"), - {}, -}; - -enum arm_pmu_type armpmu_device_type(struct platform_device *pdev) -{ - const struct of_device_id *of_id; - const struct platform_device_id *pdev_id; - - /* provided by of_device_id table */ - if (pdev->dev.of_node) { - of_id = of_match_device(armpmu_of_device_ids, &pdev->dev); - BUG_ON(!of_id); - return (enum arm_pmu_type)of_id->data; - } - - /* Provided by platform_device_id table */ - pdev_id = platform_get_device_id(pdev); - BUG_ON(!pdev_id); - return pdev_id->driver_data; -} - -static int __devinit armpmu_device_probe(struct platform_device *pdev) -{ - return pmu_register(pdev, armpmu_device_type(pdev)); -} - -static struct platform_driver armpmu_driver = { - .driver = { - .name = "arm-pmu", - .of_match_table = armpmu_of_device_ids, - }, - .probe = armpmu_device_probe, - .id_table = armpmu_plat_device_ids, -}; - -static int __init register_pmu_driver(void) -{ - return platform_driver_register(&armpmu_driver); -} -device_initcall(register_pmu_driver); +/* + * PMU locking to ensure mutual exclusion between different subsystems. + */ +static unsigned long pmu_lock[BITS_TO_LONGS(ARM_NUM_PMU_DEVICES)]; -struct platform_device * +int reserve_pmu(enum arm_pmu_type type) { - struct platform_device *pdev; - - if (test_and_set_bit_lock(type, &pmu_lock)) { - pdev = ERR_PTR(-EBUSY); - } else if (pmu_devices[type] == NULL) { - clear_bit_unlock(type, &pmu_lock); - pdev = ERR_PTR(-ENODEV); - } else { - pdev = pmu_devices[type]; - } - - return pdev; + return test_and_set_bit_lock(type, pmu_lock) ? -EBUSY : 0; } EXPORT_SYMBOL_GPL(reserve_pmu); -int +void release_pmu(enum arm_pmu_type type) { - if (WARN_ON(!pmu_devices[type])) - return -EINVAL; - clear_bit_unlock(type, &pmu_lock); - return 0; -} -EXPORT_SYMBOL_GPL(release_pmu); - -static int -set_irq_affinity(int irq, - unsigned int cpu) -{ -#ifdef CONFIG_SMP - int err = irq_set_affinity(irq, cpumask_of(cpu)); - if (err) - pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n", - irq, cpu); - return err; -#else - return -EINVAL; -#endif -} - -static int -init_cpu_pmu(void) -{ - int i, irqs, err = 0; - struct platform_device *pdev = pmu_devices[ARM_PMU_DEVICE_CPU]; - - if (!pdev) - return -ENODEV; - - irqs = pdev->num_resources; - - /* - * If we have a single PMU interrupt that we can't shift, assume that - * we're running on a uniprocessor machine and continue. - */ - if (irqs == 1 && !irq_can_set_affinity(platform_get_irq(pdev, 0))) - return 0; - - for (i = 0; i < irqs; ++i) { - err = set_irq_affinity(platform_get_irq(pdev, i), i); - if (err) - break; - } - - return err; -} - -int -init_pmu(enum arm_pmu_type type) -{ - int err = 0; - - switch (type) { - case ARM_PMU_DEVICE_CPU: - err = init_cpu_pmu(); - break; - default: - pr_warning("attempt to initialise PMU of unknown " - "type %d\n", type); - err = -EINVAL; - } - - return err; + clear_bit_unlock(type, pmu_lock); } -EXPORT_SYMBOL_GPL(init_pmu); |