arch/arm/include/asm/pmu.h

   1 /*
   2  *  linux/arch/arm/include/asm/pmu.h
   3  *
   4  *  Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #ifndef __ARM_PMU_H__
  13 #define __ARM_PMU_H__
  14
  15 #ifdef CONFIG_CPU_HAS_PMU
  16
  17 struct pmu_irqs {
  18         const int   *irqs;
  19         int         num_irqs;
  20 };
  21
  22 /**
  23  * reserve_pmu() - reserve the hardware performance counters
  24  *
  25  * Reserve the hardware performance counters in the system for exclusive use.
  26  * The 'struct pmu_irqs' for the system is returned on success, ERR_PTR()
  27  * encoded error on failure.
  28  */
  29 extern const struct pmu_irqs *
  30 reserve_pmu(void);
  31
  32 /**
  33  * release_pmu() - Relinquish control of the performance counters
  34  *
  35  * Release the performance counters and allow someone else to use them.
  36  * Callers must have disabled the counters and released IRQs before calling
  37  * this. The 'struct pmu_irqs' returned from reserve_pmu() must be passed as
  38  * a cookie.
  39  */
  40 extern int
  41 release_pmu(const struct pmu_irqs *irqs);
  42
  43 /**
  44  * init_pmu() - Initialise the PMU.
  45  *
  46  * Initialise the system ready for PMU enabling. This should typically set the
  47  * IRQ affinity and nothing else. The users (oprofile/perf events etc) will do
  48  * the actual hardware initialisation.
  49  */
  50 extern int
  51 init_pmu(void);
  52
  53 #else /* CONFIG_CPU_HAS_PMU */
  54
  55 static inline const struct pmu_irqs *
  56 reserve_pmu(void)
  57 {
  58         return ERR_PTR(-ENODEV);
  59 }
  60
  61 static inline int
  62 release_pmu(const struct pmu_irqs *irqs)
  63 {
  64         return -ENODEV;
  65 }
  66
  67 static inline int
  68 init_pmu(void)
  69 {
  70         return -ENODEV;
  71 }
  72
  73 #endif /* CONFIG_CPU_HAS_PMU */
  74
  75 #endif /* __ARM_PMU_H__ */