diff options
| -rw-r--r-- | arch/arm/Kconfig | 5 | ||||
| -rw-r--r-- | arch/arm/include/asm/pmu.h | 75 | ||||
| -rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/pmu.c | 103 |
4 files changed, 184 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 233a222752c0..9e08891062bf 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -863,6 +863,11 @@ config XSCALE_PMU depends on CPU_XSCALE && !XSCALE_PMU_TIMER default y +config CPU_HAS_PMU + depends on CPU_V6 || CPU_V7 || XSCALE_PMU + default y + bool + if !MMU source "arch/arm/Kconfig-nommu" endif diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h new file mode 100644 index 000000000000..2829b9f981a1 --- /dev/null +++ b/arch/arm/include/asm/pmu.h @@ -0,0 +1,75 @@ +/* + * linux/arch/arm/include/asm/pmu.h + * + * Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles + * + * 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. + * + */ + +#ifndef __ARM_PMU_H__ +#define __ARM_PMU_H__ + +#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() + * encoded error on failure. + */ +extern const struct pmu_irqs * +reserve_pmu(void); + +/** + * 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 + * a cookie. + */ +extern int +release_pmu(const struct pmu_irqs *irqs); + +/** + * init_pmu() - Initialise the PMU. + * + * Initialise the system ready for PMU enabling. This should typically set the + * IRQ affinity and nothing else. The users (oprofile/perf events etc) will do + * the actual hardware initialisation. + */ +extern int +init_pmu(void); + +#else /* CONFIG_CPU_HAS_PMU */ + +static inline const struct pmu_irqs * +reserve_pmu(void) +{ + return ERR_PTR(-ENODEV); +} + +static inline int +release_pmu(const struct pmu_irqs *irqs) +{ + return -ENODEV; +} + +static inline int +init_pmu(void) +{ + return -ENODEV; +} + +#endif /* CONFIG_CPU_HAS_PMU */ + +#endif /* __ARM_PMU_H__ */ diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index dd00f747e2ad..216890d804c2 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_CPU_XSCALE) += xscale-cp0.o obj-$(CONFIG_CPU_XSC3) += xscale-cp0.o obj-$(CONFIG_CPU_MOHAWK) += xscale-cp0.o obj-$(CONFIG_IWMMXT) += iwmmxt.o +obj-$(CONFIG_CPU_HAS_PMU) += pmu.o AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt ifneq ($(CONFIG_ARCH_EBSA110),y) diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c new file mode 100644 index 000000000000..a124312e343f --- /dev/null +++ b/arch/arm/kernel/pmu.c @@ -0,0 +1,103 @@ +/* + * linux/arch/arm/kernel/pmu.c + * + * Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles + * + * 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/cpumask.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include <asm/pmu.h> + +/* + * 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 const struct pmu_irqs pmu_irqs = { + .irqs = irqs, + .num_irqs = ARRAY_SIZE(irqs), +}; + +static volatile long pmu_lock; + +const struct pmu_irqs * +reserve_pmu(void) +{ + return test_and_set_bit_lock(0, &pmu_lock) ? ERR_PTR(-EBUSY) : + &pmu_irqs; +} +EXPORT_SYMBOL_GPL(reserve_pmu); + +int +release_pmu(const struct pmu_irqs *irqs) +{ + if (WARN_ON(irqs != &pmu_irqs)) + return -EINVAL; + clear_bit_unlock(0, &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 0; +#endif +} + +int +init_pmu(void) +{ + int i, err = 0; + + for (i = 0; i < pmu_irqs.num_irqs; ++i) { + err = set_irq_affinity(pmu_irqs.irqs[i], i); + if (err) + break; + } + + return err; +} +EXPORT_SYMBOL_GPL(init_pmu); |