ltt-tracer.h

   1 /*
   2  * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
   3  *
   4  * This contains the definitions for the Linux Trace Toolkit tracer.
   5  *
   6  * Dual LGPL v2.1/GPL v2 license.
   7  */
   8
   9 #ifndef _LTT_TRACER_H
  10 #define _LTT_TRACER_H
  11
  12 #include <stdarg.h>
  13 #include <linux/types.h>
  14 #include <linux/limits.h>
  15 #include <linux/list.h>
  16 #include <linux/cache.h>
  17 #include <linux/timex.h>
  18 #include <linux/wait.h>
  19 #include <asm/atomic.h>
  20 #include <asm/local.h>
  21
  22 #include "wrapper/trace-clock.h"
  23 #include "ltt-tracer-core.h"
  24 #include "ltt-events.h"
  25
  26 /* Number of bytes to log with a read/write event */
  27 #define LTT_LOG_RW_SIZE                 32L
  28
  29 /* Maximum number of callbacks per marker */
  30 #define LTT_NR_CALLBACKS        10
  31
  32 struct ltt_serialize_closure;
  33
  34 /* Serialization callback */
  35 typedef size_t (*ltt_serialize_cb)(struct lib_ring_buffer *buf,
  36                                    size_t buf_offset,
  37                                    struct ltt_serialize_closure *closure,
  38                                    void *serialize_private,
  39                                    unsigned int stack_pos_ctx,
  40                                    int *largest_align,
  41                                    const char *fmt, va_list *args);
  42
  43 struct ltt_serialize_closure {
  44         ltt_serialize_cb *callbacks;
  45         long cb_args[LTT_NR_CALLBACKS];
  46         unsigned int cb_idx;
  47 };
  48
  49 size_t ltt_serialize_data(struct lib_ring_buffer *buf, size_t buf_offset,
  50                           struct ltt_serialize_closure *closure,
  51                           void *serialize_private, unsigned int stack_pos_ctx,
  52                           int *largest_align, const char *fmt, va_list *args);
  53
  54 enum ltt_channels {
  55         LTT_CHANNEL_METADATA,
  56         LTT_CHANNEL_FD_STATE,
  57         LTT_CHANNEL_GLOBAL_STATE,
  58         LTT_CHANNEL_IRQ_STATE,
  59         LTT_CHANNEL_MODULE_STATE,
  60         LTT_CHANNEL_NETIF_STATE,
  61         LTT_CHANNEL_SOFTIRQ_STATE,
  62         LTT_CHANNEL_SWAP_STATE,
  63         LTT_CHANNEL_SYSCALL_STATE,
  64         LTT_CHANNEL_TASK_STATE,
  65         LTT_CHANNEL_VM_STATE,
  66         LTT_CHANNEL_FS,
  67         LTT_CHANNEL_INPUT,
  68         LTT_CHANNEL_IPC,
  69         LTT_CHANNEL_KERNEL,
  70         LTT_CHANNEL_MM,
  71         LTT_CHANNEL_RCU,
  72         LTT_CHANNEL_DEFAULT,
  73 };
  74
  75 /*
  76  * Hardcoded event headers
  77  *
  78  * event header for a trace with active heartbeat : 27 bits timestamps
  79  *
  80  * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
  81  * trace alignment value must be done.
  82  *
  83  * Remember that the C compiler does align each member on the boundary
  84  * equivalent to their own size.
  85  *
  86  * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
  87  * bytes aligned, so the buffer header and trace header are aligned.
  88  *
  89  * Event headers are aligned depending on the trace alignment option.
  90  *
  91  * Note using C structure bitfields for cross-endianness and portability
  92  * concerns.
  93  */
  94
  95 #define LTT_RESERVED_EVENTS     3
  96 #define LTT_EVENT_BITS          5
  97 #define LTT_FREE_EVENTS         ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
  98 #define LTT_TSC_BITS            27
  99 #define LTT_TSC_MASK            ((1 << LTT_TSC_BITS) - 1)
 100
 101 struct event_header {
 102         u32 id_time;            /* 5 bits event id (MSB); 27 bits time (LSB) */
 103 };
 104
 105 /* Reservation flags */
 106 #define LTT_RFLAG_ID                    (1 << 0)
 107 #define LTT_RFLAG_ID_SIZE               (1 << 1)
 108 #define LTT_RFLAG_ID_SIZE_TSC           (1 << 2)
 109
 110 #define LTT_MAX_SMALL_SIZE              0xFFFFU
 111
 112 /*
 113  * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
 114  * specifically with CPU frequency scaling someday, so using an interpolation
 115  * between the start and end of buffer values is not flexible enough. Using an
 116  * immediate frequency value permits to calculate directly the times for parts
 117  * of a buffer that would be before a frequency change.
 118  *
 119  * Keep the natural field alignment for _each field_ within this structure if
 120  * you ever add/remove a field from this header. Packed attribute is not used
 121  * because gcc generates poor code on at least powerpc and mips. Don't ever
 122  * let gcc add padding between the structure elements.
 123  */
 124 struct packet_header {
 125         uint32_t magic;                 /*
 126                                          * Trace magic number.
 127                                          * contains endianness information.
 128                                          */
 129         uint8_t trace_uuid[16];
 130         uint32_t stream_id;
 131         uint64_t timestamp_begin;       /* Cycle count at subbuffer start */
 132         uint64_t timestamp_end; /* Cycle count at subbuffer end */
 133         uint32_t content_size;          /* Size of data in subbuffer */
 134         uint32_t packet_size;           /* Subbuffer size (include padding) */
 135         uint32_t events_lost;           /*
 136                                          * Events lost in this subbuffer since
 137                                          * the beginning of the trace.
 138                                          * (may overflow)
 139                                          */
 140         /* TODO: move to metadata */
 141 #if 0
 142         uint8_t major_version;
 143         uint8_t minor_version;
 144         uint8_t arch_size;              /* Architecture pointer size */
 145         uint8_t alignment;              /* LTT data alignment */
 146         uint64_t start_time_sec;        /* NTP-corrected start time */
 147         uint64_t start_time_usec;
 148         uint64_t start_freq;            /*
 149                                          * Frequency at trace start,
 150                                          * used all along the trace.
 151                                          */
 152         uint32_t freq_scale;            /* Frequency scaling (divisor) */
 153 #endif //0
 154         uint8_t header_end[0];          /* End of header */
 155 };
 156
 157 /* Tracer properties */
 158 #define CTF_MAGIC_NUMBER                0xC1FC1FC1
 159 #define TSDL_MAGIC_NUMBER               0x75D11D57
 160 #define LTT_TRACER_VERSION_MAJOR        3
 161 #define LTT_TRACER_VERSION_MINOR        0
 162
 163 /*
 164  * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
 165  * nearly full buffer. User space won't use this last amount of space when in
 166  * blocking mode. This space also includes the event header that would be
 167  * written by this user space event.
 168  */
 169 #define LTT_RESERVE_CRITICAL            4096
 170
 171 /* Register and unregister function pointers */
 172
 173 enum ltt_module_function {
 174         LTT_FUNCTION_RUN_FILTER,
 175         LTT_FUNCTION_FILTER_CONTROL,
 176         LTT_FUNCTION_STATEDUMP
 177 };
 178
 179 extern int ltt_module_register(enum ltt_module_function name, void *function,
 180                                struct module *owner);
 181 extern void ltt_module_unregister(enum ltt_module_function name);
 182
 183 /* Exported control function */
 184
 185 void ltt_core_register(int (*function)(u8, void *));
 186
 187 void ltt_core_unregister(void);
 188
 189 extern
 190 void ltt_statedump_register_kprobes_dump(void (*callback)(void *call_data));
 191 extern
 192 void ltt_statedump_unregister_kprobes_dump(void (*callback)(void *call_data));
 193
 194 extern void ltt_dump_softirq_vec(void *call_data);
 195
 196 #ifdef CONFIG_HAVE_LTT_DUMP_TABLES
 197 extern void ltt_dump_sys_call_table(void *call_data);
 198 extern void ltt_dump_idt_table(void *call_data);
 199 #else
 200 static inline void ltt_dump_sys_call_table(void *call_data)
 201 {
 202 }
 203
 204 static inline void ltt_dump_idt_table(void *call_data)
 205 {
 206 }
 207 #endif
 208
 209 #endif /* _LTT_TRACER_H */