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[~shefty/rdma-dev.git] / kernel / events / internal.h
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
10 struct 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
37 extern void rb_free(struct ring_buffer *rb);
38 extern struct ring_buffer *
39 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
40 extern void perf_event_wakeup(struct perf_event *event);
41
42 extern void
43 perf_event_header__init_id(struct perf_event_header *header,
44                            struct perf_sample_data *data,
45                            struct perf_event *event);
46 extern void
47 perf_event__output_id_sample(struct perf_event *event,
48                              struct perf_output_handle *handle,
49                              struct perf_sample_data *sample);
50
51 extern struct page *
52 perf_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
61 static inline int page_order(struct ring_buffer *rb)
62 {
63         return rb->page_order;
64 }
65
66 #else
67
68 static inline int page_order(struct ring_buffer *rb)
69 {
70         return 0;
71 }
72 #endif
73
74 static inline unsigned long perf_data_size(struct ring_buffer *rb)
75 {
76         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
77 }
78
79 static 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 */
104 extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
105 extern int get_callchain_buffers(void);
106 extern void put_callchain_buffers(void);
107
108 static 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
130 static inline void put_recursion_context(int *recursion, int rctx)
131 {
132         barrier();
133         recursion[rctx]--;
134 }
135
136 #endif /* _KERNEL_EVENTS_INTERNAL_H */