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 #include <linux/interrupt.h>
  16
  17 enum arm_pmu_type {
  18         ARM_PMU_DEVICE_CPU      = 0,
  19         ARM_NUM_PMU_DEVICES,
  20 };
  21
  22 /*
  23  * struct arm_pmu_platdata - ARM PMU platform data
  24  *
  25  * @handle_irq: an optional handler which will be called from the interrupt and
  26  * passed the address of the low level handler, and can be used to implement
  27  * any platform specific handling before or after calling it.
  28  */
  29 struct arm_pmu_platdata {
  30         irqreturn_t (*handle_irq)(int irq, void *dev,
  31                                   irq_handler_t pmu_handler);
  32 };
  33
  34 #ifdef CONFIG_CPU_HAS_PMU
  35
  36 /**
  37  * reserve_pmu() - reserve the hardware performance counters
  38  *
  39  * Reserve the hardware performance counters in the system for exclusive use.
  40  * The platform_device for the system is returned on success, ERR_PTR()
  41  * encoded error on failure.
  42  */
  43 extern struct platform_device *
  44 reserve_pmu(enum arm_pmu_type type);
  45
  46 /**
  47  * release_pmu() - Relinquish control of the performance counters
  48  *
  49  * Release the performance counters and allow someone else to use them.
  50  * Callers must have disabled the counters and released IRQs before calling
  51  * this. The platform_device returned from reserve_pmu() must be passed as
  52  * a cookie.
  53  */
  54 extern int
  55 release_pmu(enum arm_pmu_type type);
  56
  57 /**
  58  * init_pmu() - Initialise the PMU.
  59  *
  60  * Initialise the system ready for PMU enabling. This should typically set the
  61  * IRQ affinity and nothing else. The users (oprofile/perf events etc) will do
  62  * the actual hardware initialisation.
  63  */
  64 extern int
  65 init_pmu(enum arm_pmu_type type);
  66
  67 #else /* CONFIG_CPU_HAS_PMU */
  68
  69 #include <linux/err.h>
  70
  71 static inline struct platform_device *
  72 reserve_pmu(enum arm_pmu_type type)
  73 {
  74         return ERR_PTR(-ENODEV);
  75 }
  76
  77 static inline int
  78 release_pmu(enum arm_pmu_type type)
  79 {
  80         return -ENODEV;
  81 }
  82
  83 static inline int
  84 init_pmu(enum arm_pmu_type type)
  85 {
  86         return -ENODEV;
  87 }
  88
  89 #endif /* CONFIG_CPU_HAS_PMU */
  90
  91 #endif /* __ARM_PMU_H__ */