pmu.c 798 字节
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/*
 *  linux/arch/arm/kernel/pmu.c
 *
 *  Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
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 *  Copyright (C) 2010 ARM Ltd, Will Deacon
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 *
 * 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/err.h>
#include <linux/kernel.h>
#include <linux/module.h>

#include <asm/pmu.h>

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/*
 * PMU locking to ensure mutual exclusion between different subsystems.
 */
static unsigned long pmu_lock[BITS_TO_LONGS(ARM_NUM_PMU_DEVICES)];
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int
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reserve_pmu(enum arm_pmu_type type)
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{
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	return test_and_set_bit_lock(type, pmu_lock) ? -EBUSY : 0;
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}
EXPORT_SYMBOL_GPL(reserve_pmu);

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void
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release_pmu(enum arm_pmu_type type)
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{
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	clear_bit_unlock(type, pmu_lock);
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}