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, op_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(op_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 */ 121