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);
28void flush_cpu_work(void);
29
30/* CPU buffer is composed of such entries (which are
31 * also used for context switch notes)
32 */
33struct op_sample {
34 unsigned long eip;
35 unsigned long event;
36 unsigned long data[0];
37};
38
39struct op_entry;
40
41struct oprofile_cpu_buffer {
42 unsigned long buffer_size;
43 struct task_struct *last_task;
44 int last_is_kernel;
45 int tracing;
46 unsigned long sample_received;
47 unsigned long sample_lost_overflow;
48 unsigned long backtrace_aborted;
49 unsigned long sample_invalid_eip;
50 int cpu;
51 struct delayed_work work;
52};
53
54DECLARE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer);
55
56/*
57 * Resets the cpu buffer to a sane state.
58 *
59 * reset these to invalid values; the next sample collected will
60 * populate the buffer with proper values to initialize the buffer
61 */
62static inline void op_cpu_buffer_reset(int cpu)
63{
64 struct oprofile_cpu_buffer *cpu_buf = &per_cpu(op_cpu_buffer, cpu);
65
66 cpu_buf->last_is_kernel = -1;
67 cpu_buf->last_task = NULL;
68}
69
70/*
71 * op_cpu_buffer_add_data() and op_cpu_buffer_write_commit() may be
72 * called only if op_cpu_buffer_write_reserve() did not return NULL or
73 * entry->event != NULL, otherwise entry->size or entry->event will be
74 * used uninitialized.
75 */
76
77struct op_sample
78*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
79int op_cpu_buffer_write_commit(struct op_entry *entry);
80struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu);
81unsigned long op_cpu_buffer_entries(int cpu);
82
83/* returns the remaining free size of data in the entry */
84static inline
85int op_cpu_buffer_add_data(struct op_entry *entry, unsigned long val)
86{
87 if (!entry->size)
88 return 0;
89 *entry->data = val;
90 entry->size--;
91 entry->data++;
92 return entry->size;
93}
94
95/* returns the size of data in the entry */
96static inline
97int op_cpu_buffer_get_size(struct op_entry *entry)
98{
99 return entry->size;
100}
101
102/* returns 0 if empty or the size of data including the current value */
103static inline
104int op_cpu_buffer_get_data(struct op_entry *entry, unsigned long *val)
105{
106 int size = entry->size;
107 if (!size)
108 return 0;
109 *val = *entry->data;
110 entry->size--;
111 entry->data++;
112 return size;
113}
114
115/* extra data flags */
116#define KERNEL_CTX_SWITCH (1UL << 0)
117#define IS_KERNEL (1UL << 1)
118#define TRACE_BEGIN (1UL << 2)
119#define USER_CTX_SWITCH (1UL << 3)
120
121#endif /* OPROFILE_CPU_BUFFER_H */
122