arch/arm/kernel/pmu.c

   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
  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
  32 release_pmu(enum arm_pmu_type type)
  33 {
  34         clear_bit_unlock(type, pmu_lock);
  35 }
  36 EXPORT_SYMBOL_GPL(release_pmu);