arch/arm/kernel/perf_event_cpu.c - linux - Git at Google

 /*
  * 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.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
  * Copyright (C) 2012 ARM Limited
  *
  * Author: Will Deacon <will.deacon@arm.com>
  */
 #define pr_fmt(fmt) "CPU PMU: " fmt

 #include <linux/bitmap.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/irq.h>
 #include <linux/irqdesc.h>

 #include <asm/cputype.h>
 #include <asm/irq_regs.h>
 #include <asm/pmu.h>

 /* Set at runtime when we know what CPU type we are. */
 static struct arm_pmu *cpu_pmu;

 /*
  * Despite the names, these two functions are CPU-specific and are used
  * by the OProfile/perf code.
  */
 const char *perf_pmu_name(void)
 {
 	if (!cpu_pmu)
 		return NULL;

 	return cpu_pmu->name;
 }
 EXPORT_SYMBOL_GPL(perf_pmu_name);

 int perf_num_counters(void)
 {
 	int max_events = 0;

 	if (cpu_pmu != NULL)
 		max_events = cpu_pmu->num_events;

 	return max_events;
 }
 EXPORT_SYMBOL_GPL(perf_num_counters);

 /* Include the PMU-specific implementations. */
 #include "perf_event_xscale.c"
 #include "perf_event_v6.c"
 #include "perf_event_v7.c"

 static void cpu_pmu_enable_percpu_irq(void *data)
 {
 	int irq = *(int *)data;

 	enable_percpu_irq(irq, IRQ_TYPE_NONE);
 }

 static void cpu_pmu_disable_percpu_irq(void *data)
 {
 	int irq = *(int *)data;

 	disable_percpu_irq(irq);
 }

 static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
 {
 	int i, irq, irqs;
 	struct platform_device *pmu_device = cpu_pmu->plat_device;
 	struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;

 	irqs = min(pmu_device->num_resources, num_possible_cpus());

 	irq = platform_get_irq(pmu_device, 0);
 	if (irq >= 0 && irq_is_percpu(irq)) {
 		on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1);
 		free_percpu_irq(irq, &hw_events->percpu_pmu);
 	} else {
 		for (i = 0; i < irqs; ++i) {
 			int cpu = i;

 			if (cpu_pmu->irq_affinity)
 				cpu = cpu_pmu->irq_affinity[i];

 			if (!cpumask_test_and_clear_cpu(cpu, &cpu_pmu->active_irqs))
 				continue;
 			irq = platform_get_irq(pmu_device, i);
 			if (irq >= 0)
 				free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu));
 		}
 	}
 }

 static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
 {
 	int i, err, irq, irqs;
 	struct platform_device *pmu_device = cpu_pmu->plat_device;
 	struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;

 	if (!pmu_device)
 		return -ENODEV;

 	irqs = min(pmu_device->num_resources, num_possible_cpus());
 	if (irqs < 1) {
 		pr_warn_once("perf/ARM: No irqs for PMU defined, sampling events not supported\n");
 		return 0;
 	}

 	irq = platform_get_irq(pmu_device, 0);
 	if (irq >= 0 && irq_is_percpu(irq)) {
 		err = request_percpu_irq(irq, handler, "arm-pmu",
 					 &hw_events->percpu_pmu);
 		if (err) {
 			pr_err("unable to request IRQ%d for ARM PMU counters\n",
 				irq);
 			return err;
 		}
 		on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);
 	} else {
 		for (i = 0; i < irqs; ++i) {
 			int cpu = i;

 			err = 0;
 			irq = platform_get_irq(pmu_device, i);
 			if (irq < 0)
 				continue;

 			if (cpu_pmu->irq_affinity)
 				cpu = cpu_pmu->irq_affinity[i];

 			/*
 			 * If we have a single PMU interrupt that we can't shift,
 			 * assume that we're running on a uniprocessor machine and
 			 * continue. Otherwise, continue without this interrupt.
 			 */
 			if (irq_set_affinity(irq, cpumask_of(cpu)) && irqs > 1) {
 				pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n",
 					irq, cpu);
 				continue;
 			}

 			err = request_irq(irq, handler,
 					  IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
 					  per_cpu_ptr(&hw_events->percpu_pmu, cpu));
 			if (err) {
 				pr_err("unable to request IRQ%d for ARM PMU counters\n",
 					irq);
 				return err;
 			}

 			cpumask_set_cpu(cpu, &cpu_pmu->active_irqs);
 		}
 	}

 	return 0;
 }

 /*
  * PMU hardware loses all context when a CPU goes offline.
  * When a CPU is hotplugged back in, since some hardware registers are
  * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
  * junk values out of them.
  */
 static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
 			  void *hcpu)
 {
 	struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb);

 	if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
 		return NOTIFY_DONE;

 	if (pmu->reset)
 		pmu->reset(pmu);
 	else
 		return NOTIFY_DONE;

 	return NOTIFY_OK;
 }

 static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
 {
 	int err;
 	int cpu;
 	struct pmu_hw_events __percpu *cpu_hw_events;

 	cpu_hw_events = alloc_percpu(struct pmu_hw_events);
 	if (!cpu_hw_events)
 		return -ENOMEM;

 	cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify;
 	err = register_cpu_notifier(&cpu_pmu->hotplug_nb);
 	if (err)
 		goto out_hw_events;

 	for_each_possible_cpu(cpu) {
 		struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu);
 		raw_spin_lock_init(&events->pmu_lock);
 		events->percpu_pmu = cpu_pmu;
 	}

 	cpu_pmu->hw_events	= cpu_hw_events;
 	cpu_pmu->request_irq	= cpu_pmu_request_irq;
 	cpu_pmu->free_irq	= cpu_pmu_free_irq;

 	/* Ensure the PMU has sane values out of reset. */
 	if (cpu_pmu->reset)
 		on_each_cpu(cpu_pmu->reset, cpu_pmu, 1);

 	/* If no interrupts available, set the corresponding capability flag */
 	if (!platform_get_irq(cpu_pmu->plat_device, 0))
 		cpu_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;

 	return 0;

 out_hw_events:
 	free_percpu(cpu_hw_events);
 	return err;
 }

 static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
 {
 	unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
 	free_percpu(cpu_pmu->hw_events);
 }

 /*
  * PMU platform driver and devicetree bindings.
  */
 static const struct of_device_id cpu_pmu_of_device_ids[] = {
 	{.compatible = "arm,cortex-a17-pmu",	.data = armv7_a17_pmu_init},
 	{.compatible = "arm,cortex-a15-pmu",	.data = armv7_a15_pmu_init},
 	{.compatible = "arm,cortex-a12-pmu",	.data = armv7_a12_pmu_init},
 	{.compatible = "arm,cortex-a9-pmu",	.data = armv7_a9_pmu_init},
 	{.compatible = "arm,cortex-a8-pmu",	.data = armv7_a8_pmu_init},
 	{.compatible = "arm,cortex-a7-pmu",	.data = armv7_a7_pmu_init},
 	{.compatible = "arm,cortex-a5-pmu",	.data = armv7_a5_pmu_init},
 	{.compatible = "arm,arm11mpcore-pmu",	.data = armv6mpcore_pmu_init},
 	{.compatible = "arm,arm1176-pmu",	.data = armv6_1176_pmu_init},
 	{.compatible = "arm,arm1136-pmu",	.data = armv6_1136_pmu_init},
 	{.compatible = "qcom,krait-pmu",	.data = krait_pmu_init},
 	{.compatible = "qcom,scorpion-pmu",	.data = scorpion_pmu_init},
 	{.compatible = "qcom,scorpion-mp-pmu",	.data = scorpion_mp_pmu_init},
 	{},
 };

 static struct platform_device_id cpu_pmu_plat_device_ids[] = {
 	{.name = "arm-pmu"},
 	{.name = "armv6-pmu"},
 	{.name = "armv7-pmu"},
 	{.name = "xscale-pmu"},
 	{},
 };

 static const struct pmu_probe_info pmu_probe_table[] = {
 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
 	ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
 	ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A8, armv7_a8_pmu_init),
 	ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A9, armv7_a9_pmu_init),
 	XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V1, xscale1pmu_init),
 	XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V2, xscale2pmu_init),
 	{ /* sentinel value */ }
 };

 /*
  * CPU PMU identification and probing.
  */
 static int probe_current_pmu(struct arm_pmu *pmu)
 {
 	int cpu = get_cpu();
 	unsigned int cpuid = read_cpuid_id();
 	int ret = -ENODEV;
 	const struct pmu_probe_info *info;

 	pr_info("probing PMU on CPU %d\n", cpu);

 	for (info = pmu_probe_table; info->init != NULL; info++) {
 		if ((cpuid & info->mask) != info->cpuid)
 			continue;
 		ret = info->init(pmu);
 		break;
 	}

 	put_cpu();
 	return ret;
 }

 static int of_pmu_irq_cfg(struct platform_device *pdev)
 {
 	int i, irq;
 	int *irqs;

 	/* Don't bother with PPIs; they're already affine */
 	irq = platform_get_irq(pdev, 0);
 	if (irq >= 0 && irq_is_percpu(irq))
 		return 0;

 	irqs = kcalloc(pdev->num_resources, sizeof(*irqs), GFP_KERNEL);
 	if (!irqs)
 		return -ENOMEM;

 	for (i = 0; i < pdev->num_resources; ++i) {
 		struct device_node *dn;
 		int cpu;

 		dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity",
 				      i);
 		if (!dn) {
 			pr_warn("Failed to parse %s/interrupt-affinity[%d]\n",
 				of_node_full_name(pdev->dev.of_node), i);
 			break;
 		}

 		for_each_possible_cpu(cpu)
 			if (arch_find_n_match_cpu_physical_id(dn, cpu, NULL))
 				break;

 		of_node_put(dn);
 		if (cpu >= nr_cpu_ids) {
 			pr_warn("Failed to find logical CPU for %s\n",
 				dn->name);
 			break;
 		}

 		irqs[i] = cpu;
 	}

 	if (i == pdev->num_resources)
 		cpu_pmu->irq_affinity = irqs;
 	else
 		kfree(irqs);

 	return 0;
 }

 static int cpu_pmu_device_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *of_id;
 	const int (*init_fn)(struct arm_pmu *);
 	struct device_node *node = pdev->dev.of_node;
 	struct arm_pmu *pmu;
 	int ret = -ENODEV;

 	if (cpu_pmu) {
 		pr_info("attempt to register multiple PMU devices!\n");
 		return -ENOSPC;
 	}

 	pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL);
 	if (!pmu) {
 		pr_info("failed to allocate PMU device!\n");
 		return -ENOMEM;
 	}

 	cpu_pmu = pmu;
 	cpu_pmu->plat_device = pdev;

 	if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
 		init_fn = of_id->data;

 		ret = of_pmu_irq_cfg(pdev);
 		if (!ret)
 			ret = init_fn(pmu);
 	} else {
 		ret = probe_current_pmu(pmu);
 	}

 	if (ret) {
 		pr_info("failed to probe PMU!\n");
 		goto out_free;
 	}

 	ret = cpu_pmu_init(cpu_pmu);
 	if (ret)
 		goto out_free;

 	ret = armpmu_register(cpu_pmu, -1);
 	if (ret)
 		goto out_destroy;

 	return 0;

 out_destroy:
 	cpu_pmu_destroy(cpu_pmu);
 out_free:
 	pr_info("failed to register PMU devices!\n");
 	kfree(pmu);
 	return ret;
 }

 static struct platform_driver cpu_pmu_driver = {
 	.driver		= {
 		.name	= "arm-pmu",
 		.pm	= &armpmu_dev_pm_ops,
 		.of_match_table = cpu_pmu_of_device_ids,
 	},
 	.probe		= cpu_pmu_device_probe,
 	.id_table	= cpu_pmu_plat_device_ids,
 };

 static int __init register_pmu_driver(void)
 {
 	return platform_driver_register(&cpu_pmu_driver);
 }
 device_initcall(register_pmu_driver);
	/*
	* 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.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*
	* Copyright (C) 2012 ARM Limited
	*
	* Author: Will Deacon <will.deacon@arm.com>
	*/
	#define pr_fmt(fmt) "CPU PMU: " fmt

	#include <linux/bitmap.h>
	#include <linux/export.h>
	#include <linux/kernel.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/spinlock.h>
	#include <linux/irq.h>
	#include <linux/irqdesc.h>

	#include <asm/cputype.h>
	#include <asm/irq_regs.h>
	#include <asm/pmu.h>

	/* Set at runtime when we know what CPU type we are. */
	static struct arm_pmu *cpu_pmu;

	/*
	* Despite the names, these two functions are CPU-specific and are used
	* by the OProfile/perf code.
	*/
	const char *perf_pmu_name(void)
	{
	if (!cpu_pmu)
	return NULL;

	return cpu_pmu->name;
	}
	EXPORT_SYMBOL_GPL(perf_pmu_name);

	int perf_num_counters(void)
	{
	int max_events = 0;

	if (cpu_pmu != NULL)
	max_events = cpu_pmu->num_events;

	return max_events;
	}
	EXPORT_SYMBOL_GPL(perf_num_counters);

	/* Include the PMU-specific implementations. */
	#include "perf_event_xscale.c"
	#include "perf_event_v6.c"
	#include "perf_event_v7.c"

	static void cpu_pmu_enable_percpu_irq(void *data)
	{
	int irq = (int )data;

	enable_percpu_irq(irq, IRQ_TYPE_NONE);
	}

	static void cpu_pmu_disable_percpu_irq(void *data)
	{
	int irq = (int )data;

	disable_percpu_irq(irq);
	}

	static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
	{
	int i, irq, irqs;
	struct platform_device *pmu_device = cpu_pmu->plat_device;
	struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;

	irqs = min(pmu_device->num_resources, num_possible_cpus());

	irq = platform_get_irq(pmu_device, 0);
	if (irq >= 0 && irq_is_percpu(irq)) {
	on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1);
	free_percpu_irq(irq, &hw_events->percpu_pmu);
	} else {
	for (i = 0; i < irqs; ++i) {
	int cpu = i;

	if (cpu_pmu->irq_affinity)
	cpu = cpu_pmu->irq_affinity[i];

	if (!cpumask_test_and_clear_cpu(cpu, &cpu_pmu->active_irqs))
	continue;
	irq = platform_get_irq(pmu_device, i);
	if (irq >= 0)
	free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu));
	}
	}
	}

	static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
	{
	int i, err, irq, irqs;
	struct platform_device *pmu_device = cpu_pmu->plat_device;
	struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;

	if (!pmu_device)
	return -ENODEV;

	irqs = min(pmu_device->num_resources, num_possible_cpus());
	if (irqs < 1) {
	pr_warn_once("perf/ARM: No irqs for PMU defined, sampling events not supported\n");
	return 0;
	}

	irq = platform_get_irq(pmu_device, 0);
	if (irq >= 0 && irq_is_percpu(irq)) {
	err = request_percpu_irq(irq, handler, "arm-pmu",
	&hw_events->percpu_pmu);
	if (err) {
	pr_err("unable to request IRQ%d for ARM PMU counters\n",
	irq);
	return err;
	}
	on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);
	} else {
	for (i = 0; i < irqs; ++i) {
	int cpu = i;

	err = 0;
	irq = platform_get_irq(pmu_device, i);
	if (irq < 0)
	continue;

	if (cpu_pmu->irq_affinity)
	cpu = cpu_pmu->irq_affinity[i];

	/*
	* If we have a single PMU interrupt that we can't shift,
	* assume that we're running on a uniprocessor machine and
	* continue. Otherwise, continue without this interrupt.
	*/
	if (irq_set_affinity(irq, cpumask_of(cpu)) && irqs > 1) {
	pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n",
	irq, cpu);
	continue;
	}

	err = request_irq(irq, handler,
	IRQF_NOBALANCING \| IRQF_NO_THREAD, "arm-pmu",
	per_cpu_ptr(&hw_events->percpu_pmu, cpu));
	if (err) {
	pr_err("unable to request IRQ%d for ARM PMU counters\n",
	irq);
	return err;
	}

	cpumask_set_cpu(cpu, &cpu_pmu->active_irqs);
	}
	}

	return 0;
	}

	/*
	* PMU hardware loses all context when a CPU goes offline.
	* When a CPU is hotplugged back in, since some hardware registers are
	* UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
	* junk values out of them.
	*/
	static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
	void *hcpu)
	{
	struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb);

	if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
	return NOTIFY_DONE;

	if (pmu->reset)
	pmu->reset(pmu);
	else
	return NOTIFY_DONE;

	return NOTIFY_OK;
	}

	static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
	{
	int err;
	int cpu;
	struct pmu_hw_events __percpu *cpu_hw_events;

	cpu_hw_events = alloc_percpu(struct pmu_hw_events);
	if (!cpu_hw_events)
	return -ENOMEM;

	cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify;
	err = register_cpu_notifier(&cpu_pmu->hotplug_nb);
	if (err)
	goto out_hw_events;

	for_each_possible_cpu(cpu) {
	struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu);
	raw_spin_lock_init(&events->pmu_lock);
	events->percpu_pmu = cpu_pmu;
	}

	cpu_pmu->hw_events = cpu_hw_events;
	cpu_pmu->request_irq = cpu_pmu_request_irq;
	cpu_pmu->free_irq = cpu_pmu_free_irq;

	/* Ensure the PMU has sane values out of reset. */
	if (cpu_pmu->reset)
	on_each_cpu(cpu_pmu->reset, cpu_pmu, 1);

	/* If no interrupts available, set the corresponding capability flag */
	if (!platform_get_irq(cpu_pmu->plat_device, 0))
	cpu_pmu->pmu.capabilities \|= PERF_PMU_CAP_NO_INTERRUPT;

	return 0;

	out_hw_events:
	free_percpu(cpu_hw_events);
	return err;
	}

	static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
	{
	unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
	free_percpu(cpu_pmu->hw_events);
	}

	/*
	* PMU platform driver and devicetree bindings.
	*/
	static const struct of_device_id cpu_pmu_of_device_ids[] = {
	{.compatible = "arm,cortex-a17-pmu", .data = armv7_a17_pmu_init},
	{.compatible = "arm,cortex-a15-pmu", .data = armv7_a15_pmu_init},
	{.compatible = "arm,cortex-a12-pmu", .data = armv7_a12_pmu_init},
	{.compatible = "arm,cortex-a9-pmu", .data = armv7_a9_pmu_init},
	{.compatible = "arm,cortex-a8-pmu", .data = armv7_a8_pmu_init},
	{.compatible = "arm,cortex-a7-pmu", .data = armv7_a7_pmu_init},
	{.compatible = "arm,cortex-a5-pmu", .data = armv7_a5_pmu_init},
	{.compatible = "arm,arm11mpcore-pmu", .data = armv6mpcore_pmu_init},
	{.compatible = "arm,arm1176-pmu", .data = armv6_1176_pmu_init},
	{.compatible = "arm,arm1136-pmu", .data = armv6_1136_pmu_init},
	{.compatible = "qcom,krait-pmu", .data = krait_pmu_init},
	{.compatible = "qcom,scorpion-pmu", .data = scorpion_pmu_init},
	{.compatible = "qcom,scorpion-mp-pmu", .data = scorpion_mp_pmu_init},
	{},
	};

	static struct platform_device_id cpu_pmu_plat_device_ids[] = {
	{.name = "arm-pmu"},
	{.name = "armv6-pmu"},
	{.name = "armv7-pmu"},
	{.name = "xscale-pmu"},
	{},
	};

	static const struct pmu_probe_info pmu_probe_table[] = {
	ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
	ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
	ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
	ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
	ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A8, armv7_a8_pmu_init),
	ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A9, armv7_a9_pmu_init),
	XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V1, xscale1pmu_init),
	XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V2, xscale2pmu_init),
	{ /* sentinel value */ }
	};

	/*
	* CPU PMU identification and probing.
	*/
	static int probe_current_pmu(struct arm_pmu *pmu)
	{
	int cpu = get_cpu();
	unsigned int cpuid = read_cpuid_id();
	int ret = -ENODEV;
	const struct pmu_probe_info *info;

	pr_info("probing PMU on CPU %d\n", cpu);

	for (info = pmu_probe_table; info->init != NULL; info++) {
	if ((cpuid & info->mask) != info->cpuid)
	continue;
	ret = info->init(pmu);
	break;
	}

	put_cpu();
	return ret;
	}

	static int of_pmu_irq_cfg(struct platform_device *pdev)
	{
	int i, irq;
	int *irqs;

	/* Don't bother with PPIs; they're already affine */
	irq = platform_get_irq(pdev, 0);
	if (irq >= 0 && irq_is_percpu(irq))
	return 0;

	irqs = kcalloc(pdev->num_resources, sizeof(*irqs), GFP_KERNEL);
	if (!irqs)
	return -ENOMEM;

	for (i = 0; i < pdev->num_resources; ++i) {
	struct device_node *dn;
	int cpu;

	dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity",
	i);
	if (!dn) {
	pr_warn("Failed to parse %s/interrupt-affinity[%d]\n",
	of_node_full_name(pdev->dev.of_node), i);
	break;
	}

	for_each_possible_cpu(cpu)
	if (arch_find_n_match_cpu_physical_id(dn, cpu, NULL))
	break;

	of_node_put(dn);
	if (cpu >= nr_cpu_ids) {
	pr_warn("Failed to find logical CPU for %s\n",
	dn->name);
	break;
	}

	irqs[i] = cpu;
	}

	if (i == pdev->num_resources)
	cpu_pmu->irq_affinity = irqs;
	else
	kfree(irqs);

	return 0;
	}

	static int cpu_pmu_device_probe(struct platform_device *pdev)
	{
	const struct of_device_id *of_id;
	const int (init_fn)(struct arm_pmu );
	struct device_node *node = pdev->dev.of_node;
	struct arm_pmu *pmu;
	int ret = -ENODEV;

	if (cpu_pmu) {
	pr_info("attempt to register multiple PMU devices!\n");
	return -ENOSPC;
	}

	pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL);
	if (!pmu) {
	pr_info("failed to allocate PMU device!\n");
	return -ENOMEM;
	}

	cpu_pmu = pmu;
	cpu_pmu->plat_device = pdev;

	if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
	init_fn = of_id->data;

	ret = of_pmu_irq_cfg(pdev);
	if (!ret)
	ret = init_fn(pmu);
	} else {
	ret = probe_current_pmu(pmu);
	}

	if (ret) {
	pr_info("failed to probe PMU!\n");
	goto out_free;
	}

	ret = cpu_pmu_init(cpu_pmu);
	if (ret)
	goto out_free;

	ret = armpmu_register(cpu_pmu, -1);
	if (ret)
	goto out_destroy;

	return 0;

	out_destroy:
	cpu_pmu_destroy(cpu_pmu);
	out_free:
	pr_info("failed to register PMU devices!\n");
	kfree(pmu);
	return ret;
	}

	static struct platform_driver cpu_pmu_driver = {
	.driver = {
	.name = "arm-pmu",
	.pm = &armpmu_dev_pm_ops,
	.of_match_table = cpu_pmu_of_device_ids,
	},
	.probe = cpu_pmu_device_probe,
	.id_table = cpu_pmu_plat_device_ids,
	};

	static int __init register_pmu_driver(void)
	{
	return platform_driver_register(&cpu_pmu_driver);
	}
	device_initcall(register_pmu_driver);