#ifndef _KERNEL_EVENTS_INTERNAL_H#define _KERNEL_EVENTS_INTERNAL_H #define RING_BUFFER_WRITABLE		0x01 struct ring_buffer {	atomic_t			refcount;	struct rcu_head			rcu_head;#ifdef CONFIG_PERF_USE_VMALLOC	struct work_struct		work;	int				page_order;	/* allocation order  */#endif	int				nr_pages;	/* nr of data pages  */	int				writable;	/* are we writable   */ 	atomic_t			poll;		/* POLL_ for wakeups */ 	local_t				head;		/* write position    */	local_t				nest;		/* nested writers    */	local_t				events;		/* event limit       */	local_t				wakeup;		/* wakeup stamp      */	local_t				lost;		/* nr records lost   */ 	long				watermark;	/* wakeup watermark  */	/* poll crap */	spinlock_t			event_lock;	struct list_head		event_list; 	struct perf_event_mmap_page	*user_page;	void				*data_pages[0];}; extern void rb_free(struct ring_buffer *rb);extern struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags);extern void perf_event_wakeup(struct perf_event *event); extern voidperf_event_header__init_id(struct perf_event_header *header,			   struct perf_sample_data *data,			   struct perf_event *event);extern voidperf_event__output_id_sample(struct perf_event *event,			     struct perf_output_handle *handle,			     struct perf_sample_data *sample); extern struct page *perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff); #ifdef CONFIG_PERF_USE_VMALLOC/* * Back perf_mmap() with vmalloc memory. * * Required for architectures that have d-cache aliasing issues. */ static inline int page_order(struct ring_buffer *rb){	return rb->page_order;} #else static inline int page_order(struct ring_buffer *rb){	return 0;}#endif static unsigned long perf_data_size(struct ring_buffer *rb){	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));} static inline void__output_copy(struct perf_output_handle *handle,		   const void *buf, unsigned int len){	do {		unsigned long size = min_t(unsigned long, handle->size, len); 		memcpy(handle->addr, buf, size); 		len -= size;		handle->addr += size;		buf += size;		handle->size -= size;		if (!handle->size) {			struct ring_buffer *rb = handle->rb; 			handle->page++;			handle->page &= rb->nr_pages - 1;			handle->addr = rb->data_pages[handle->page];			handle->size = PAGE_SIZE << page_order(rb);		}	} while (len);} #endif /* _KERNEL_EVENTS_INTERNAL_H */