49c006b937
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 <jamie.iles@picochip.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
142 lines
2.7 KiB
C
142 lines
2.7 KiB
C
/*
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* linux/arch/arm/kernel/pmu.c
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*
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* Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
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* Copyright (C) 2010 ARM Ltd, Will Deacon
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#define pr_fmt(fmt) "PMU: " fmt
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#include <linux/cpumask.h>
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <asm/pmu.h>
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static volatile long pmu_lock;
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static struct platform_device *pmu_devices[ARM_NUM_PMU_DEVICES];
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static int __devinit pmu_device_probe(struct platform_device *pdev)
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{
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if (pdev->id < 0 || pdev->id >= ARM_NUM_PMU_DEVICES) {
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pr_warning("received registration request for unknown "
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"device %d\n", pdev->id);
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return -EINVAL;
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}
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if (pmu_devices[pdev->id])
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pr_warning("registering new PMU device type %d overwrites "
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"previous registration!\n", pdev->id);
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else
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pr_info("registered new PMU device of type %d\n",
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pdev->id);
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pmu_devices[pdev->id] = pdev;
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return 0;
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}
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static struct platform_driver pmu_driver = {
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.driver = {
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.name = "arm-pmu",
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},
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.probe = pmu_device_probe,
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};
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static int __init register_pmu_driver(void)
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{
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return platform_driver_register(&pmu_driver);
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}
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device_initcall(register_pmu_driver);
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struct platform_device *
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reserve_pmu(enum arm_pmu_type device)
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{
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struct platform_device *pdev;
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if (test_and_set_bit_lock(device, &pmu_lock)) {
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pdev = ERR_PTR(-EBUSY);
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} else if (pmu_devices[device] == NULL) {
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clear_bit_unlock(device, &pmu_lock);
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pdev = ERR_PTR(-ENODEV);
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} else {
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pdev = pmu_devices[device];
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}
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return pdev;
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}
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EXPORT_SYMBOL_GPL(reserve_pmu);
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int
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release_pmu(struct platform_device *pdev)
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{
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if (WARN_ON(pdev != pmu_devices[pdev->id]))
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return -EINVAL;
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clear_bit_unlock(pdev->id, &pmu_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(release_pmu);
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static int
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set_irq_affinity(int irq,
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unsigned int cpu)
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{
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#ifdef CONFIG_SMP
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int err = irq_set_affinity(irq, cpumask_of(cpu));
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if (err)
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pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
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irq, cpu);
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return err;
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#else
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return 0;
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#endif
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}
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static int
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init_cpu_pmu(void)
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{
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int i, err = 0;
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struct platform_device *pdev = pmu_devices[ARM_PMU_DEVICE_CPU];
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if (!pdev) {
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err = -ENODEV;
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goto out;
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}
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for (i = 0; i < pdev->num_resources; ++i) {
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err = set_irq_affinity(platform_get_irq(pdev, i), i);
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if (err)
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break;
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}
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out:
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return err;
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}
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int
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init_pmu(enum arm_pmu_type device)
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{
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int err = 0;
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switch (device) {
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case ARM_PMU_DEVICE_CPU:
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err = init_cpu_pmu();
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break;
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default:
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pr_warning("attempt to initialise unknown device %d\n",
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device);
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err = -EINVAL;
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}
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return err;
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}
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EXPORT_SYMBOL_GPL(init_pmu);
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