From 49c006b93769a86bec2b32b9234abf016ac0d50e Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 29 Apr 2010 17:13:24 +0100 Subject: ARM: 6064/1: pmu: register IRQs at runtime The current PMU infrastructure for ARM requires that the IRQs for the PMU device are fixed at compile time and are selected based on the ARCH_ or MACH_ flags. This has the disadvantage of tying the Kernel down to a particular board as far as profiling is concerned. This patch replaces the compile-time IRQ registration with a runtime mechanism which allows the IRQs to be registered with the framework as a platform_device. A further advantage of this change is that there is scope for registering different types of performance counters in the future by changing the id of the platform_device and attaching different resources to it. Acked-by: Jamie Iles Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/include/asm/pmu.h | 27 ++++----- arch/arm/kernel/perf_event.c | 52 +++++++++++------- arch/arm/kernel/pmu.c | 127 ++++++++++++++++++++++++++++--------------- 3 files changed, 126 insertions(+), 80 deletions(-) diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h index 44bec1f02cb0..8ccea012722c 100644 --- a/arch/arm/include/asm/pmu.h +++ b/arch/arm/include/asm/pmu.h @@ -19,31 +19,26 @@ enum arm_pmu_type { #ifdef CONFIG_CPU_HAS_PMU -struct pmu_irqs { - const int *irqs; - int num_irqs; -}; - /** * reserve_pmu() - reserve the hardware performance counters * * Reserve the hardware performance counters in the system for exclusive use. - * The 'struct pmu_irqs' for the system is returned on success, ERR_PTR() + * The platform_device for the system is returned on success, ERR_PTR() * encoded error on failure. */ -extern const struct pmu_irqs * -reserve_pmu(void); +extern struct platform_device * +reserve_pmu(enum arm_pmu_type device); /** * 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 'struct pmu_irqs' returned from reserve_pmu() must be passed as + * this. The platform_device returned from reserve_pmu() must be passed as * a cookie. */ extern int -release_pmu(const struct pmu_irqs *irqs); +release_pmu(struct platform_device *pdev); /** * init_pmu() - Initialise the PMU. @@ -53,24 +48,26 @@ release_pmu(const struct pmu_irqs *irqs); * the actual hardware initialisation. */ extern int -init_pmu(void); +init_pmu(enum arm_pmu_type device); #else /* CONFIG_CPU_HAS_PMU */ -static inline const struct pmu_irqs * -reserve_pmu(void) +#include + +static inline struct platform_device * +reserve_pmu(enum arm_pmu_type device) { return ERR_PTR(-ENODEV); } static inline int -release_pmu(const struct pmu_irqs *irqs) +release_pmu(struct platform_device *pdev) { return -ENODEV; } static inline int -init_pmu(void) +init_pmu(enum arm_pmu_type device) { return -ENODEV; } diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 9e70f2053f9a..89a77fcb13e3 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -26,7 +27,7 @@ #include #include -static const struct pmu_irqs *pmu_irqs; +static struct platform_device *pmu_device; /* * Hardware lock to serialize accesses to PMU registers. Needed for the @@ -314,38 +315,44 @@ validate_group(struct perf_event *event) static int armpmu_reserve_hardware(void) { - int i; - int err; + int i, err = -ENODEV, irq; - pmu_irqs = reserve_pmu(); - if (IS_ERR(pmu_irqs)) { + pmu_device = reserve_pmu(ARM_PMU_DEVICE_CPU); + if (IS_ERR(pmu_device)) { pr_warning("unable to reserve pmu\n"); - return PTR_ERR(pmu_irqs); + return PTR_ERR(pmu_device); } - init_pmu(); + init_pmu(ARM_PMU_DEVICE_CPU); - if (pmu_irqs->num_irqs < 1) { + if (pmu_device->num_resources < 1) { pr_err("no irqs for PMUs defined\n"); return -ENODEV; } - for (i = 0; i < pmu_irqs->num_irqs; ++i) { - err = request_irq(pmu_irqs->irqs[i], armpmu->handle_irq, + for (i = 0; i < pmu_device->num_resources; ++i) { + irq = platform_get_irq(pmu_device, i); + if (irq < 0) + continue; + + err = request_irq(irq, armpmu->handle_irq, IRQF_DISABLED | IRQF_NOBALANCING, "armpmu", NULL); if (err) { - pr_warning("unable to request IRQ%d for ARM " - "perf counters\n", pmu_irqs->irqs[i]); + pr_warning("unable to request IRQ%d for ARM perf " + "counters\n", irq); break; } } if (err) { - for (i = i - 1; i >= 0; --i) - free_irq(pmu_irqs->irqs[i], NULL); - release_pmu(pmu_irqs); - pmu_irqs = NULL; + for (i = i - 1; i >= 0; --i) { + irq = platform_get_irq(pmu_device, i); + if (irq >= 0) + free_irq(irq, NULL); + } + release_pmu(pmu_device); + pmu_device = NULL; } return err; @@ -354,14 +361,17 @@ armpmu_reserve_hardware(void) static void armpmu_release_hardware(void) { - int i; + int i, irq; - for (i = pmu_irqs->num_irqs - 1; i >= 0; --i) - free_irq(pmu_irqs->irqs[i], NULL); + for (i = pmu_device->num_resources - 1; i >= 0; --i) { + irq = platform_get_irq(pmu_device, i); + if (irq >= 0) + free_irq(irq, NULL); + } armpmu->stop(); - release_pmu(pmu_irqs); - pmu_irqs = NULL; + release_pmu(pmu_device); + pmu_device = NULL; } static atomic_t active_events = ATOMIC_INIT(0); diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c index a124312e343f..b8af96ea62e6 100644 --- a/arch/arm/kernel/pmu.c +++ b/arch/arm/kernel/pmu.c @@ -2,6 +2,7 @@ * linux/arch/arm/kernel/pmu.c * * Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles + * Copyright (C) 2010 ARM Ltd, Will Deacon * * 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 @@ -9,65 +10,78 @@ * */ +#define pr_fmt(fmt) "PMU: " fmt + #include #include #include #include #include +#include #include -/* - * Define the IRQs for the system. We could use something like a platform - * device but that seems fairly heavyweight for this. Also, the performance - * counters can't be removed or hotplugged. - * - * Ordering is important: init_pmu() will use the ordering to set the affinity - * to the corresponding core. e.g. the first interrupt will go to cpu 0, the - * second goes to cpu 1 etc. - */ -static const int irqs[] = { -#if defined(CONFIG_ARCH_OMAP2) - 3, -#elif defined(CONFIG_ARCH_BCMRING) - IRQ_PMUIRQ, -#elif defined(CONFIG_MACH_REALVIEW_EB) - IRQ_EB11MP_PMU_CPU0, - IRQ_EB11MP_PMU_CPU1, - IRQ_EB11MP_PMU_CPU2, - IRQ_EB11MP_PMU_CPU3, -#elif defined(CONFIG_ARCH_OMAP3) - INT_34XX_BENCH_MPU_EMUL, -#elif defined(CONFIG_ARCH_IOP32X) - IRQ_IOP32X_CORE_PMU, -#elif defined(CONFIG_ARCH_IOP33X) - IRQ_IOP33X_CORE_PMU, -#elif defined(CONFIG_ARCH_PXA) - IRQ_PMU, -#endif -}; +static volatile long pmu_lock; + +static struct platform_device *pmu_devices[ARM_NUM_PMU_DEVICES]; + +static int __devinit pmu_device_probe(struct platform_device *pdev) +{ + + if (pdev->id < 0 || pdev->id >= ARM_NUM_PMU_DEVICES) { + pr_warning("received registration request for unknown " + "device %d\n", pdev->id); + return -EINVAL; + } + + if (pmu_devices[pdev->id]) + pr_warning("registering new PMU device type %d overwrites " + "previous registration!\n", pdev->id); + else + pr_info("registered new PMU device of type %d\n", + pdev->id); -static const struct pmu_irqs pmu_irqs = { - .irqs = irqs, - .num_irqs = ARRAY_SIZE(irqs), + pmu_devices[pdev->id] = pdev; + return 0; +} + +static struct platform_driver pmu_driver = { + .driver = { + .name = "arm-pmu", + }, + .probe = pmu_device_probe, }; -static volatile long pmu_lock; +static int __init register_pmu_driver(void) +{ + return platform_driver_register(&pmu_driver); +} +device_initcall(register_pmu_driver); -const struct pmu_irqs * -reserve_pmu(void) +struct platform_device * +reserve_pmu(enum arm_pmu_type device) { - return test_and_set_bit_lock(0, &pmu_lock) ? ERR_PTR(-EBUSY) : - &pmu_irqs; + struct platform_device *pdev; + + if (test_and_set_bit_lock(device, &pmu_lock)) { + pdev = ERR_PTR(-EBUSY); + } else if (pmu_devices[device] == NULL) { + clear_bit_unlock(device, &pmu_lock); + pdev = ERR_PTR(-ENODEV); + } else { + pdev = pmu_devices[device]; + } + + return pdev; } EXPORT_SYMBOL_GPL(reserve_pmu); int -release_pmu(const struct pmu_irqs *irqs) +release_pmu(struct platform_device *pdev) { - if (WARN_ON(irqs != &pmu_irqs)) + if (WARN_ON(pdev != pmu_devices[pdev->id])) return -EINVAL; - clear_bit_unlock(0, &pmu_lock); + clear_bit_unlock(pdev->id, &pmu_lock); return 0; } EXPORT_SYMBOL_GPL(release_pmu); @@ -87,17 +101,42 @@ set_irq_affinity(int irq, #endif } -int -init_pmu(void) +static int +init_cpu_pmu(void) { int i, err = 0; + struct platform_device *pdev = pmu_devices[ARM_PMU_DEVICE_CPU]; + + if (!pdev) { + err = -ENODEV; + goto out; + } - for (i = 0; i < pmu_irqs.num_irqs; ++i) { - err = set_irq_affinity(pmu_irqs.irqs[i], i); + for (i = 0; i < pdev->num_resources; ++i) { + err = set_irq_affinity(platform_get_irq(pdev, i), i); if (err) break; } +out: + return err; +} + +int +init_pmu(enum arm_pmu_type device) +{ + int err = 0; + + switch (device) { + case ARM_PMU_DEVICE_CPU: + err = init_cpu_pmu(); + break; + default: + pr_warning("attempt to initialise unknown device %d\n", + device); + err = -EINVAL; + } + return err; } EXPORT_SYMBOL_GPL(init_pmu); -- cgit v1.2.3