1#ifndef _KERNEL_EVENTS_INTERNAL_H
  2#define _KERNEL_EVENTS_INTERNAL_H
  3
  4#include <linux/hardirq.h>
  5
  6/* Buffer handling */
  7
  8#define RING_BUFFER_WRITABLE		0x01
  9
 10struct ring_buffer {
 11	atomic_t			refcount;
 12	struct rcu_head			rcu_head;
 13#ifdef CONFIG_PERF_USE_VMALLOC
 14	struct work_struct		work;
 15	int				page_order;	/* allocation order  */
 16#endif
 17	int				nr_pages;	/* nr of data pages  */
 18	int				writable;	/* are we writable   */
 19
 20	atomic_t			poll;		/* POLL_ for wakeups */
 21
 22	local_t				head;		/* write position    */
 23	local_t				nest;		/* nested writers    */
 24	local_t				events;		/* event limit       */
 25	local_t				wakeup;		/* wakeup stamp      */
 26	local_t				lost;		/* nr records lost   */
 27
 28	long				watermark;	/* wakeup watermark  */
 29	/* poll crap */
 30	spinlock_t			event_lock;
 31	struct list_head		event_list;
 32
 33	struct perf_event_mmap_page	*user_page;
 34	void				*data_pages[0];
 35};
 36
 37extern void rb_free(struct ring_buffer *rb);
 38extern struct ring_buffer *
 39rb_alloc(int nr_pages, long watermark, int cpu, int flags);
 40extern void perf_event_wakeup(struct perf_event *event);
 41
 42extern void
 43perf_event_header__init_id(struct perf_event_header *header,
 44			   struct perf_sample_data *data,
 45			   struct perf_event *event);
 46extern void
 47perf_event__output_id_sample(struct perf_event *event,
 48			     struct perf_output_handle *handle,
 49			     struct perf_sample_data *sample);
 50
 51extern struct page *
 52perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
 53
 54#ifdef CONFIG_PERF_USE_VMALLOC
 55/*
 56 * Back perf_mmap() with vmalloc memory.
 57 *
 58 * Required for architectures that have d-cache aliasing issues.
 59 */
 60
 61static inline int page_order(struct ring_buffer *rb)
 62{
 63	return rb->page_order;
 64}
 65
 66#else
 67
 68static inline int page_order(struct ring_buffer *rb)
 69{
 70	return 0;
 71}
 72#endif
 73
 74static inline unsigned long perf_data_size(struct ring_buffer *rb)
 75{
 76	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 77}
 78
 79static inline void
 80__output_copy(struct perf_output_handle *handle,
 81		   const void *buf, unsigned int len)
 82{
 83	do {
 84		unsigned long size = min_t(unsigned long, handle->size, len);
 85
 86		memcpy(handle->addr, buf, size);
 87
 88		len -= size;
 89		handle->addr += size;
 90		buf += size;
 91		handle->size -= size;
 92		if (!handle->size) {
 93			struct ring_buffer *rb = handle->rb;
 94
 95			handle->page++;
 96			handle->page &= rb->nr_pages - 1;
 97			handle->addr = rb->data_pages[handle->page];
 98			handle->size = PAGE_SIZE << page_order(rb);
 99		}
100	} while (len);
101}
102
103/* Callchain handling */
104extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
105extern int get_callchain_buffers(void);
106extern void put_callchain_buffers(void);
107
108static inline int get_recursion_context(int *recursion)
109{
110	int rctx;
111
112	if (in_nmi())
113		rctx = 3;
114	else if (in_irq())
115		rctx = 2;
116	else if (in_softirq())
117		rctx = 1;
118	else
119		rctx = 0;
120
121	if (recursion[rctx])
122		return -1;
123
124	recursion[rctx]++;
125	barrier();
126
127	return rctx;
128}
129
130static inline void put_recursion_context(int *recursion, int rctx)
131{
132	barrier();
133	recursion[rctx]--;
134}
135
136#endif /* _KERNEL_EVENTS_INTERNAL_H */