linux/arch/arm/include/asm/pmu.h
Jamie Iles 0f4f0672ac ARM: 5899/2: arm: provide a mechanism to reserve performance counters
To add support for perf events and to allow the hardware counters to be
shared with oprofile, we need a way to reserve access to the pmu
(performance monitor unit). Platforms with PMU interrupts should
register the interrupts in arch/arm/kernel/pmu.c

Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:23:43 +00:00

76 lines
1.7 KiB
C

/*
* linux/arch/arm/include/asm/pmu.h
*
* Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
*
* 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.
*
*/
#ifndef __ARM_PMU_H__
#define __ARM_PMU_H__
#ifdef CONFIG_CPU_HAS_PMU
struct pmu_irqs {
const int *irqs;
int num_irqs;
};
/**
* reserve_pmu() - reserve the hardware performance counters
*
* Reserve the hardware performance counters in the system for exclusive use.
* The 'struct pmu_irqs' for the system is returned on success, ERR_PTR()
* encoded error on failure.
*/
extern const struct pmu_irqs *
reserve_pmu(void);
/**
* release_pmu() - Relinquish control of the performance counters
*
* Release the performance counters and allow someone else to use them.
* Callers must have disabled the counters and released IRQs before calling
* this. The 'struct pmu_irqs' returned from reserve_pmu() must be passed as
* a cookie.
*/
extern int
release_pmu(const struct pmu_irqs *irqs);
/**
* init_pmu() - Initialise the PMU.
*
* Initialise the system ready for PMU enabling. This should typically set the
* IRQ affinity and nothing else. The users (oprofile/perf events etc) will do
* the actual hardware initialisation.
*/
extern int
init_pmu(void);
#else /* CONFIG_CPU_HAS_PMU */
static inline const struct pmu_irqs *
reserve_pmu(void)
{
return ERR_PTR(-ENODEV);
}
static inline int
release_pmu(const struct pmu_irqs *irqs)
{
return -ENODEV;
}
static inline int
init_pmu(void)
{
return -ENODEV;
}
#endif /* CONFIG_CPU_HAS_PMU */
#endif /* __ARM_PMU_H__ */