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1/**
2 * @file cpu_buffer.h
3 *
4 * @remark Copyright 2002-2009 OProfile authors
5 * @remark Read the file COPYING
6 *
7 * @author John Levon <levon@movementarian.org>
8 * @author Robert Richter <robert.richter@amd.com>
9 */
10
11#ifndef OPROFILE_CPU_BUFFER_H
12#define OPROFILE_CPU_BUFFER_H
13
14#include <linux/types.h>
15#include <linux/spinlock.h>
16#include <linux/workqueue.h>
17#include <linux/cache.h>
18#include <linux/sched.h>
19#include <linux/ring_buffer.h>
20
21struct task_struct;
22
23int alloc_cpu_buffers(void);
24void free_cpu_buffers(void);
25
26void start_cpu_work(void);
27void end_cpu_work(void);
28
29/* CPU buffer is composed of such entries (which are
30 * also used for context switch notes)
31 */
32struct op_sample {
33 unsigned long eip;
34 unsigned long event;
35 unsigned long data[0];
36};
37
38struct op_entry;
39
40struct oprofile_cpu_buffer {
41 unsigned long buffer_size;
42 struct task_struct *last_task;
43 int last_is_kernel;
44 int tracing;
45 unsigned long sample_received;
46 unsigned long sample_lost_overflow;
47 unsigned long backtrace_aborted;
48 unsigned long sample_invalid_eip;
49 int cpu;
50 struct delayed_work work;
51};
52
53DECLARE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer);
54
55/*
56 * Resets the cpu buffer to a sane state.
57 *
58 * reset these to invalid values; the next sample collected will
59 * populate the buffer with proper values to initialize the buffer
60 */
61static inline void op_cpu_buffer_reset(int cpu)
62{
63 struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);
64
65 cpu_buf->last_is_kernel = -1;
66 cpu_buf->last_task = NULL;
67}
68
69/*
70 * op_cpu_buffer_add_data() and op_cpu_buffer_write_commit() may be
71 * called only if op_cpu_buffer_write_reserve() did not return NULL or
72 * entry->event != NULL, otherwise entry->size or entry->event will be
73 * used uninitialized.
74 */
75
76struct op_sample
77*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
78int op_cpu_buffer_write_commit(struct op_entry *entry);
79struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu);
80unsigned long op_cpu_buffer_entries(int cpu);
81
82/* returns the remaining free size of data in the entry */
83static inline
84int op_cpu_buffer_add_data(struct op_entry *entry, unsigned long val)
85{
86 if (!entry->size)
87 return 0;
88 *entry->data = val;
89 entry->size--;
90 entry->data++;
91 return entry->size;
92}
93
94/* returns the size of data in the entry */
95static inline
96int op_cpu_buffer_get_size(struct op_entry *entry)
97{
98 return entry->size;
99}
100
101/* returns 0 if empty or the size of data including the current value */
102static inline
103int op_cpu_buffer_get_data(struct op_entry *entry, unsigned long *val)
104{
105 int size = entry->size;
106 if (!size)
107 return 0;
108 *val = *entry->data;
109 entry->size--;
110 entry->data++;
111 return size;
112}
113
114/* extra data flags */
115#define KERNEL_CTX_SWITCH (1UL << 0)
116#define IS_KERNEL (1UL << 1)
117#define TRACE_BEGIN (1UL << 2)
118#define USER_CTX_SWITCH (1UL << 3)
119
120#endif /* OPROFILE_CPU_BUFFER_H */