1 /*
2  *  linux/arch/arm/kernel/pmu.c
3  *
4  *  Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
5  *  Copyright (C) 2010 ARM Ltd, Will Deacon
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  */
12 
13 #include <linux/err.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 
17 #include <asm/pmu.h>
18 
19 /*
20  * PMU locking to ensure mutual exclusion between different subsystems.
21  */
22 static unsigned long pmu_lock[BITS_TO_LONGS(ARM_NUM_PMU_DEVICES)];
23 
24 int
reserve_pmu(enum arm_pmu_type type)25 reserve_pmu(enum arm_pmu_type type)
26 {
27 	return test_and_set_bit_lock(type, pmu_lock) ? -EBUSY : 0;
28 }
29 EXPORT_SYMBOL_GPL(reserve_pmu);
30 
31 void
release_pmu(enum arm_pmu_type type)32 release_pmu(enum arm_pmu_type type)
33 {
34 	clear_bit_unlock(type, pmu_lock);
35 }
36 EXPORT_SYMBOL_GPL(release_pmu);
37