linux/arch/arm/include/asm/pmu.h
Will Deacon 49c006b937 ARM: 6064/1: pmu: register IRQs at runtime
The current PMU infrastructure for ARM requires that the IRQs for the PMU
device are fixed at compile time and are selected based on the ARCH_ or MACH_ flags. This has the disadvantage of tying the Kernel down to a
particular board as far as profiling is concerned.

This patch replaces the compile-time IRQ registration with a runtime mechanism which allows the IRQs to be registered with the framework as
a platform_device.

A further advantage of this change is that there is scope for registering
different types of performance counters in the future by changing the id
of the platform_device and attaching different resources to it.

Acked-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-05-17 11:53:57 +01:00

78 lines
1.8 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__
enum arm_pmu_type {
ARM_PMU_DEVICE_CPU = 0,
ARM_NUM_PMU_DEVICES,
};
#ifdef CONFIG_CPU_HAS_PMU
/**
* reserve_pmu() - reserve the hardware performance counters
*
* Reserve the hardware performance counters in the system for exclusive use.
* The platform_device for the system is returned on success, ERR_PTR()
* encoded error on failure.
*/
extern struct platform_device *
reserve_pmu(enum arm_pmu_type device);
/**
* 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 platform_device returned from reserve_pmu() must be passed as
* a cookie.
*/
extern int
release_pmu(struct platform_device *pdev);
/**
* 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(enum arm_pmu_type device);
#else /* CONFIG_CPU_HAS_PMU */
#include <linux/err.h>
static inline struct platform_device *
reserve_pmu(enum arm_pmu_type device)
{
return ERR_PTR(-ENODEV);
}
static inline int
release_pmu(struct platform_device *pdev)
{
return -ENODEV;
}
static inline int
init_pmu(enum arm_pmu_type device)
{
return -ENODEV;
}
#endif /* CONFIG_CPU_HAS_PMU */
#endif /* __ARM_PMU_H__ */