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internal.h
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1 #ifndef _KERNEL_EVENTS_INTERNAL_H
2 #define _KERNEL_EVENTS_INTERNAL_H
3 
4 #include <linux/hardirq.h>
5 #include <linux/uaccess.h>
6 
7 /* Buffer handling */
8 
9 #define RING_BUFFER_WRITABLE 0x01
10 
11 struct ring_buffer {
14 #ifdef CONFIG_PERF_USE_VMALLOC
15  struct work_struct work;
16  int page_order; /* allocation order */
17 #endif
18  int nr_pages; /* nr of data pages */
19  int writable; /* are we writable */
20 
21  atomic_t poll; /* POLL_ for wakeups */
22 
23  local_t head; /* write position */
24  local_t nest; /* nested writers */
25  local_t events; /* event limit */
26  local_t wakeup; /* wakeup stamp */
27  local_t lost; /* nr records lost */
28 
29  long watermark; /* wakeup watermark */
30  /* poll crap */
33 
35  void *data_pages[0];
36 };
37 
38 extern void rb_free(struct ring_buffer *rb);
39 extern struct ring_buffer *
40 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
41 extern void perf_event_wakeup(struct perf_event *event);
42 
43 extern void
45  struct perf_sample_data *data,
46  struct perf_event *event);
47 extern void
49  struct perf_output_handle *handle,
50  struct perf_sample_data *sample);
51 
52 extern struct page *
53 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
54 
55 #ifdef CONFIG_PERF_USE_VMALLOC
56 /*
57  * Back perf_mmap() with vmalloc memory.
58  *
59  * Required for architectures that have d-cache aliasing issues.
60  */
61 
62 static inline int page_order(struct ring_buffer *rb)
63 {
64  return rb->page_order;
65 }
66 
67 #else
68 
69 static inline int page_order(struct ring_buffer *rb)
70 {
71  return 0;
72 }
73 #endif
74 
75 static inline unsigned long perf_data_size(struct ring_buffer *rb)
76 {
77  return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
78 }
79 
80 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \
81 static inline unsigned int \
82 func_name(struct perf_output_handle *handle, \
83  const void *buf, unsigned int len) \
84 { \
85  unsigned long size, written; \
86  \
87  do { \
88  size = min_t(unsigned long, handle->size, len); \
89  \
90  written = memcpy_func(handle->addr, buf, size); \
91  \
92  len -= written; \
93  handle->addr += written; \
94  buf += written; \
95  handle->size -= written; \
96  if (!handle->size) { \
97  struct ring_buffer *rb = handle->rb; \
98  \
99  handle->page++; \
100  handle->page &= rb->nr_pages - 1; \
101  handle->addr = rb->data_pages[handle->page]; \
102  handle->size = PAGE_SIZE << page_order(rb); \
103  } \
104  } while (len && written == size); \
105  \
106  return len; \
107 }
108 
109 static inline int memcpy_common(void *dst, const void *src, size_t n)
110 {
111  memcpy(dst, src, n);
112  return n;
113 }
114 
115 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
116 
117 #define MEMCPY_SKIP(dst, src, n) (n)
118 
119 DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP)
120 
121 #ifndef arch_perf_out_copy_user
122 #define arch_perf_out_copy_user __copy_from_user_inatomic
123 #endif
124 
125 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
126 
127 /* Callchain handling */
130 extern int get_callchain_buffers(void);
131 extern void put_callchain_buffers(void);
132 
133 static inline int get_recursion_context(int *recursion)
134 {
135  int rctx;
136 
137  if (in_nmi())
138  rctx = 3;
139  else if (in_irq())
140  rctx = 2;
141  else if (in_softirq())
142  rctx = 1;
143  else
144  rctx = 0;
145 
146  if (recursion[rctx])
147  return -1;
148 
149  recursion[rctx]++;
150  barrier();
151 
152  return rctx;
153 }
154 
155 static inline void put_recursion_context(int *recursion, int rctx)
156 {
157  barrier();
158  recursion[rctx]--;
159 }
160 
161 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
162 static inline bool arch_perf_have_user_stack_dump(void)
163 {
164  return true;
165 }
166 
167 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
168 #else
169 static inline bool arch_perf_have_user_stack_dump(void)
170 {
171  return false;
172 }
173 
174 #define perf_user_stack_pointer(regs) 0
175 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
176 
177 #endif /* _KERNEL_EVENTS_INTERNAL_H */