Provide a mechanism that allows running code in IRQ context. It is most useful for NMI code that needs to interact with the rest of the system -- like wakeup a task to drain buffers. Perf currently has such a mechanism, so extract that and provide it as a generic feature, independent of perf so that others may also benefit. The IRQ context callback is generated through self-IPIs where possible, or on architectures like powerpc the decrementer (the built-in timer facility) is set to generate an interrupt immediately. Architectures that don't have anything like this get to do with a callback from the timer tick. These architectures can call irq_work_run() at the tail of any IRQ handlers that might enqueue such work (like the perf IRQ handler) to avoid undue latencies in processing the work. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [ various fixes ] Signed-off-by: Huang Ying <ying.huang@intel.com> LKML-Reference: <1287036094.7768.291.camel@yhuang-dev> Signed-off-by: Ingo Molnar <mingo@elte.hu>
		
			
				
	
	
		
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			C
		
	
	
	
	
	
			
		
		
	
	
			29 lines
		
	
	
	
		
			758 B
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef __ASM_SH_PERF_EVENT_H
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| #define __ASM_SH_PERF_EVENT_H
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| 
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| struct hw_perf_event;
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| 
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| #define MAX_HWEVENTS	2
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| 
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| struct sh_pmu {
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| 	const char	*name;
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| 	unsigned int	num_events;
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| 	void		(*disable_all)(void);
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| 	void		(*enable_all)(void);
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| 	void		(*enable)(struct hw_perf_event *, int);
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| 	void		(*disable)(struct hw_perf_event *, int);
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| 	u64		(*read)(int);
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| 	int		(*event_map)(int);
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| 	unsigned int	max_events;
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| 	unsigned long	raw_event_mask;
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| 	const int	(*cache_events)[PERF_COUNT_HW_CACHE_MAX]
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| 				       [PERF_COUNT_HW_CACHE_OP_MAX]
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| 				       [PERF_COUNT_HW_CACHE_RESULT_MAX];
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| };
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| 
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| /* arch/sh/kernel/perf_event.c */
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| extern int register_sh_pmu(struct sh_pmu *);
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| extern int reserve_pmc_hardware(void);
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| extern void release_pmc_hardware(void);
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| 
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| #endif /* __ASM_SH_PERF_EVENT_H */
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