libtracing/tracer.h

   1 /*
   2  * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
   3  * Copyright (C) 2009 Pierre-Marc Fournier
   4  *
   5  * This contains the definitions for the Linux Trace Toolkit tracer.
   6  *
   7  * Ported to userspace by Pierre-Marc Fournier.
   8  *
   9  * This file is released under the GPLv2.
  10  */
  11
  12 #ifndef _LTT_TRACER_H
  13 #define _LTT_TRACER_H
  14
  15 #include <sys/types.h>
  16 #include <stdarg.h>
  17 #include "relay.h"
  18 #include "list.h"
  19 #include "kernelcompat.h"
  20 #include "channels.h"
  21 #include "tracercore.h"
  22 #include "marker.h"
  23
  24 /* Number of bytes to log with a read/write event */
  25 #define LTT_LOG_RW_SIZE                 32L
  26
  27 /* Interval (in jiffies) at which the LTT per-CPU timer fires */
  28 #define LTT_PERCPU_TIMER_INTERVAL       1
  29
  30 #ifndef LTT_ARCH_TYPE
  31 #define LTT_ARCH_TYPE                   LTT_ARCH_TYPE_UNDEFINED
  32 #endif
  33
  34 #ifndef LTT_ARCH_VARIANT
  35 #define LTT_ARCH_VARIANT                LTT_ARCH_VARIANT_NONE
  36 #endif
  37
  38 struct ltt_active_marker;
  39
  40 /* Maximum number of callbacks per marker */
  41 #define LTT_NR_CALLBACKS        10
  42
  43 struct ltt_serialize_closure;
  44 struct ltt_probe_private_data;
  45
  46 /* Serialization callback '%k' */
  47 typedef size_t (*ltt_serialize_cb)(struct rchan_buf *buf, size_t buf_offset,
  48                         struct ltt_serialize_closure *closure,
  49                         void *serialize_private, int *largest_align,
  50                         const char *fmt, va_list *args);
  51
  52 struct ltt_serialize_closure {
  53         ltt_serialize_cb *callbacks;
  54         long cb_args[LTT_NR_CALLBACKS];
  55         unsigned int cb_idx;
  56 };
  57
  58 size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset,
  59                         struct ltt_serialize_closure *closure,
  60                         void *serialize_private,
  61                         int *largest_align, const char *fmt, va_list *args);
  62
  63 struct ltt_available_probe {
  64         const char *name;               /* probe name */
  65         const char *format;
  66         marker_probe_func *probe_func;
  67         ltt_serialize_cb callbacks[LTT_NR_CALLBACKS];
  68         struct list_head node;          /* registered probes list */
  69 };
  70
  71 struct ltt_probe_private_data {
  72         struct ltt_trace_struct *trace; /*
  73                                          * Target trace, for metadata
  74                                          * or statedump.
  75                                          */
  76         ltt_serialize_cb serializer;    /*
  77                                          * Serialization function override.
  78                                          */
  79         void *serialize_private;        /*
  80                                          * Private data for serialization
  81                                          * functions.
  82                                          */
  83 };
  84
  85 enum ltt_channels {
  86         LTT_CHANNEL_METADATA,
  87         LTT_CHANNEL_UST,
  88 };
  89
  90 struct ltt_active_marker {
  91         struct list_head node;          /* active markers list */
  92         const char *channel;
  93         const char *name;
  94         const char *format;
  95         struct ltt_available_probe *probe;
  96 };
  97
  98 struct marker; //ust//
  99 extern void ltt_vtrace(const struct marker *mdata, void *probe_data,
 100         void *call_data, const char *fmt, va_list *args);
 101 extern void ltt_trace(const struct marker *mdata, void *probe_data,
 102         void *call_data, const char *fmt, ...);
 103
 104 /*
 105  * Unique ID assigned to each registered probe.
 106  */
 107 enum marker_id {
 108         MARKER_ID_SET_MARKER_ID = 0,    /* Static IDs available (range 0-7) */
 109         MARKER_ID_SET_MARKER_FORMAT,
 110         MARKER_ID_COMPACT,              /* Compact IDs (range: 8-127)       */
 111         MARKER_ID_DYNAMIC,              /* Dynamic IDs (range: 128-65535)   */
 112 };
 113
 114 /* static ids 0-1 reserved for internal use. */
 115 #define MARKER_CORE_IDS         2
 116 static inline enum marker_id marker_id_type(uint16_t id)
 117 {
 118         if (id < MARKER_CORE_IDS)
 119                 return (enum marker_id)id;
 120         else
 121                 return MARKER_ID_DYNAMIC;
 122 }
 123
 124 struct user_dbg_data {
 125         unsigned long avail_size;
 126         unsigned long write;
 127         unsigned long read;
 128 };
 129
 130 struct ltt_trace_ops {
 131         /* First 32 bytes cache-hot cacheline */
 132         int (*reserve_slot) (struct ltt_trace_struct *trace,
 133                                 struct ltt_channel_struct *channel,
 134                                 void **transport_data, size_t data_size,
 135                                 size_t *slot_size, long *buf_offset, u64 *tsc,
 136                                 unsigned int *rflags,
 137                                 int largest_align);
 138         void (*commit_slot) (struct ltt_channel_struct *channel,
 139                                 void **transport_data, long buf_offset,
 140                                 size_t slot_size);
 141         void (*wakeup_channel) (struct ltt_channel_struct *ltt_channel);
 142         int (*user_blocking) (struct ltt_trace_struct *trace,
 143                                 unsigned int index, size_t data_size,
 144                                 struct user_dbg_data *dbg);
 145         /* End of first 32 bytes cacheline */
 146         int (*create_dirs) (struct ltt_trace_struct *new_trace);
 147         void (*remove_dirs) (struct ltt_trace_struct *new_trace);
 148         int (*create_channel) (const char *trace_name,
 149                                 struct ltt_trace_struct *trace,
 150                                 struct dentry *dir, const char *channel_name,
 151                                 struct ltt_channel_struct *ltt_chan,
 152                                 unsigned int subbuf_size,
 153                                 unsigned int n_subbufs, int overwrite);
 154         void (*finish_channel) (struct ltt_channel_struct *channel);
 155         void (*remove_channel) (struct ltt_channel_struct *channel);
 156         void (*user_errors) (struct ltt_trace_struct *trace,
 157                                 unsigned int index, size_t data_size,
 158                                 struct user_dbg_data *dbg);
 159 } ____cacheline_aligned;
 160
 161 struct ltt_transport {
 162         char *name;
 163         struct module *owner;
 164         struct list_head node;
 165         struct ltt_trace_ops ops;
 166 };
 167
 168 enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };
 169
 170 #define CHANNEL_FLAG_ENABLE     (1U<<0)
 171 #define CHANNEL_FLAG_OVERWRITE  (1U<<1)
 172
 173 /* Per-trace information - each trace/flight recorder represented by one */
 174 struct ltt_trace_struct {
 175         /* First 32 bytes cache-hot cacheline */
 176         struct list_head list;
 177         struct ltt_trace_ops *ops;
 178         int active;
 179         /* Second 32 bytes cache-hot cacheline */
 180         struct ltt_channel_struct *channels;
 181         unsigned int nr_channels;
 182         u32 freq_scale;
 183         u64 start_freq;
 184         u64 start_tsc;
 185         unsigned long long start_monotonic;
 186         struct timeval          start_time;
 187         struct ltt_channel_setting *settings;
 188         struct {
 189                 struct dentry                   *trace_root;
 190         } dentry;
 191         struct kref kref; /* Each channel has a kref of the trace struct */
 192         struct ltt_transport *transport;
 193         struct kref ltt_transport_kref;
 194         char trace_name[NAME_MAX];
 195 } ____cacheline_aligned;
 196
 197 /* Hardcoded event headers
 198  *
 199  * event header for a trace with active heartbeat : 27 bits timestamps
 200  *
 201  * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
 202  * trace alignment value must be done.
 203  *
 204  * Remember that the C compiler does align each member on the boundary
 205  * equivalent to their own size.
 206  *
 207  * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
 208  * bytes aligned, so the buffer header and trace header are aligned.
 209  *
 210  * Event headers are aligned depending on the trace alignment option.
 211  *
 212  * Note using C structure bitfields for cross-endianness and portability
 213  * concerns.
 214  */
 215
 216 #define LTT_RESERVED_EVENTS     3
 217 #define LTT_EVENT_BITS          5
 218 #define LTT_FREE_EVENTS         ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
 219 #define LTT_TSC_BITS            27
 220 #define LTT_TSC_MASK            ((1 << LTT_TSC_BITS) - 1)
 221
 222 struct ltt_event_header {
 223         u32 id_time;            /* 5 bits event id (MSB); 27 bits time (LSB) */
 224 };
 225
 226 /* Reservation flags */
 227 #define LTT_RFLAG_ID                    (1 << 0)
 228 #define LTT_RFLAG_ID_SIZE               (1 << 1)
 229 #define LTT_RFLAG_ID_SIZE_TSC           (1 << 2)
 230
 231 /*
 232  * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
 233  * specifically with CPU frequency scaling someday, so using an interpolation
 234  * between the start and end of buffer values is not flexible enough. Using an
 235  * immediate frequency value permits to calculate directly the times for parts
 236  * of a buffer that would be before a frequency change.
 237  *
 238  * Keep the natural field alignment for _each field_ within this structure if
 239  * you ever add/remove a field from this header. Packed attribute is not used
 240  * because gcc generates poor code on at least powerpc and mips. Don't ever
 241  * let gcc add padding between the structure elements.
 242  */
 243 struct ltt_subbuffer_header {
 244         uint64_t cycle_count_begin;     /* Cycle count at subbuffer start */
 245         uint64_t cycle_count_end;       /* Cycle count at subbuffer end */
 246         uint32_t magic_number;          /*
 247                                          * Trace magic number.
 248                                          * contains endianness information.
 249                                          */
 250         uint8_t major_version;
 251         uint8_t minor_version;
 252         uint8_t arch_size;              /* Architecture pointer size */
 253         uint8_t alignment;              /* LTT data alignment */
 254         uint64_t start_time_sec;        /* NTP-corrected start time */
 255         uint64_t start_time_usec;
 256         uint64_t start_freq;            /*
 257                                          * Frequency at trace start,
 258                                          * used all along the trace.
 259                                          */
 260         uint32_t freq_scale;            /* Frequency scaling (divisor) */
 261         uint32_t lost_size;             /* Size unused at end of subbuffer */
 262         uint32_t buf_size;              /* Size of this subbuffer */
 263         uint32_t events_lost;           /*
 264                                          * Events lost in this subbuffer since
 265                                          * the beginning of the trace.
 266                                          * (may overflow)
 267                                          */
 268         uint32_t subbuf_corrupt;        /*
 269                                          * Corrupted (lost) subbuffers since
 270                                          * the begginig of the trace.
 271                                          * (may overflow)
 272                                          */
 273         uint8_t header_end[0];          /* End of header */
 274 };
 275
 276 /**
 277  * ltt_subbuffer_header_size - called on buffer-switch to a new sub-buffer
 278  *
 279  * Return header size without padding after the structure. Don't use packed
 280  * structure because gcc generates inefficient code on some architectures
 281  * (powerpc, mips..)
 282  */
 283 static inline size_t ltt_subbuffer_header_size(void)
 284 {
 285         return offsetof(struct ltt_subbuffer_header, header_end);
 286 }
 287
 288 /*
 289  * ltt_get_header_size
 290  *
 291  * Calculate alignment offset to 32-bits. This is the alignment offset of the
 292  * event header.
 293  *
 294  * Important note :
 295  * The event header must be 32-bits. The total offset calculated here :
 296  *
 297  * Alignment of header struct on 32 bits (min arch size, header size)
 298  * + sizeof(header struct)  (32-bits)
 299  * + (opt) u16 (ext. event id)
 300  * + (opt) u16 (event_size) (if event_size == 0xFFFFUL, has ext. event size)
 301  * + (opt) u32 (ext. event size)
 302  * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
 303  *
 304  * The payload must itself determine its own alignment from the biggest type it
 305  * contains.
 306  * */
 307 static inline unsigned char ltt_get_header_size(
 308                 struct ltt_channel_struct *channel,
 309                 size_t offset,
 310                 size_t data_size,
 311                 size_t *before_hdr_pad,
 312                 unsigned int rflags)
 313 {
 314         size_t orig_offset = offset;
 315         size_t padding;
 316
 317         padding = ltt_align(offset, sizeof(struct ltt_event_header));
 318         offset += padding;
 319         offset += sizeof(struct ltt_event_header);
 320
 321         switch (rflags) {
 322         case LTT_RFLAG_ID_SIZE_TSC:
 323                 offset += sizeof(u16) + sizeof(u16);
 324                 if (data_size >= 0xFFFFU)
 325                         offset += sizeof(u32);
 326                 offset += ltt_align(offset, sizeof(u64));
 327                 offset += sizeof(u64);
 328                 break;
 329         case LTT_RFLAG_ID_SIZE:
 330                 offset += sizeof(u16) + sizeof(u16);
 331                 if (data_size >= 0xFFFFU)
 332                         offset += sizeof(u32);
 333                 break;
 334         case LTT_RFLAG_ID:
 335                 offset += sizeof(u16);
 336                 break;
 337         }
 338
 339         *before_hdr_pad = padding;
 340         return offset - orig_offset;
 341 }
 342
 343 /*
 344  * ltt_write_event_header
 345  *
 346  * Writes the event header to the offset (already aligned on 32-bits).
 347  *
 348  * @trace : trace to write to.
 349  * @channel : pointer to the channel structure..
 350  * @buf : buffer to write to.
 351  * @buf_offset : buffer offset to write to (aligned on 32 bits).
 352  * @eID : event ID
 353  * @event_size : size of the event, excluding the event header.
 354  * @tsc : time stamp counter.
 355  * @rflags : reservation flags.
 356  *
 357  * returns : offset where the event data must be written.
 358  */
 359 static inline size_t ltt_write_event_header(struct ltt_trace_struct *trace,
 360                 struct ltt_channel_struct *channel,
 361                 struct rchan_buf *buf, long buf_offset,
 362                 u16 eID, size_t event_size,
 363                 u64 tsc, unsigned int rflags)
 364 {
 365         struct ltt_event_header header;
 366         size_t small_size;
 367
 368         switch (rflags) {
 369         case LTT_RFLAG_ID_SIZE_TSC:
 370                 header.id_time = 29 << LTT_TSC_BITS;
 371                 break;
 372         case LTT_RFLAG_ID_SIZE:
 373                 header.id_time = 30 << LTT_TSC_BITS;
 374                 break;
 375         case LTT_RFLAG_ID:
 376                 header.id_time = 31 << LTT_TSC_BITS;
 377                 break;
 378         default:
 379                 header.id_time = eID << LTT_TSC_BITS;
 380                 break;
 381         }
 382         header.id_time |= (u32)tsc & LTT_TSC_MASK;
 383         ltt_relay_write(buf, buf_offset, &header, sizeof(header));
 384         buf_offset += sizeof(header);
 385
 386         switch (rflags) {
 387         case LTT_RFLAG_ID_SIZE_TSC:
 388                 small_size = min_t(size_t, event_size, 0xFFFFU);
 389                 ltt_relay_write(buf, buf_offset,
 390                         (u16[]){ (u16)eID }, sizeof(u16));
 391                 buf_offset += sizeof(u16);
 392                 ltt_relay_write(buf, buf_offset,
 393                         (u16[]){ (u16)small_size }, sizeof(u16));
 394                 buf_offset += sizeof(u16);
 395                 if (small_size == 0xFFFFU) {
 396                         ltt_relay_write(buf, buf_offset,
 397                                 (u32[]){ (u32)event_size }, sizeof(u32));
 398                         buf_offset += sizeof(u32);
 399                 }
 400                 buf_offset += ltt_align(buf_offset, sizeof(u64));
 401                 ltt_relay_write(buf, buf_offset,
 402                         (u64[]){ (u64)tsc }, sizeof(u64));
 403                 buf_offset += sizeof(u64);
 404                 break;
 405         case LTT_RFLAG_ID_SIZE:
 406                 small_size = min_t(size_t, event_size, 0xFFFFU);
 407                 ltt_relay_write(buf, buf_offset,
 408                         (u16[]){ (u16)eID }, sizeof(u16));
 409                 buf_offset += sizeof(u16);
 410                 ltt_relay_write(buf, buf_offset,
 411                         (u16[]){ (u16)small_size }, sizeof(u16));
 412                 buf_offset += sizeof(u16);
 413                 if (small_size == 0xFFFFU) {
 414                         ltt_relay_write(buf, buf_offset,
 415                                 (u32[]){ (u32)event_size }, sizeof(u32));
 416                         buf_offset += sizeof(u32);
 417                 }
 418                 break;
 419         case LTT_RFLAG_ID:
 420                 ltt_relay_write(buf, buf_offset,
 421                         (u16[]){ (u16)eID }, sizeof(u16));
 422                 buf_offset += sizeof(u16);
 423                 break;
 424         default:
 425                 break;
 426         }
 427
 428         return buf_offset;
 429 }
 430
 431 /* Lockless LTTng */
 432
 433 /* Buffer offset macros */
 434
 435 /*
 436  * BUFFER_TRUNC zeroes the subbuffer offset and the subbuffer number parts of
 437  * the offset, which leaves only the buffer number.
 438  */
 439 #define BUFFER_TRUNC(offset, chan) \
 440         ((offset) & (~((chan)->alloc_size-1)))
 441 #define BUFFER_OFFSET(offset, chan) ((offset) & ((chan)->alloc_size - 1))
 442 #define SUBBUF_OFFSET(offset, chan) ((offset) & ((chan)->subbuf_size - 1))
 443 #define SUBBUF_ALIGN(offset, chan) \
 444         (((offset) + (chan)->subbuf_size) & (~((chan)->subbuf_size - 1)))
 445 #define SUBBUF_TRUNC(offset, chan) \
 446         ((offset) & (~((chan)->subbuf_size - 1)))
 447 #define SUBBUF_INDEX(offset, chan) \
 448         (BUFFER_OFFSET((offset), chan) >> (chan)->subbuf_size_order)
 449
 450 /*
 451  * ltt_reserve_slot
 452  *
 453  * Atomic slot reservation in a LTTng buffer. It will take care of
 454  * sub-buffer switching.
 455  *
 456  * Parameters:
 457  *
 458  * @trace : the trace structure to log to.
 459  * @channel : the chanel to reserve space into.
 460  * @transport_data : specific transport data.
 461  * @data_size : size of the variable length data to log.
 462  * @slot_size : pointer to total size of the slot (out)
 463  * @buf_offset : pointer to reserve offset (out)
 464  * @tsc : pointer to the tsc at the slot reservation (out)
 465  * @rflags : reservation flags (header specificity)
 466  * @cpu : cpu id
 467  *
 468  * Return : -ENOSPC if not enough space, else 0.
 469  */
 470 static inline int ltt_reserve_slot(
 471                 struct ltt_trace_struct *trace,
 472                 struct ltt_channel_struct *channel,
 473                 void **transport_data,
 474                 size_t data_size,
 475                 size_t *slot_size,
 476                 long *buf_offset,
 477                 u64 *tsc,
 478                 unsigned int *rflags,
 479                 int largest_align)
 480 {
 481         return trace->ops->reserve_slot(trace, channel, transport_data,
 482                         data_size, slot_size, buf_offset, tsc, rflags,
 483                         largest_align);
 484 }
 485
 486
 487 /*
 488  * ltt_commit_slot
 489  *
 490  * Atomic unordered slot commit. Increments the commit count in the
 491  * specified sub-buffer, and delivers it if necessary.
 492  *
 493  * Parameters:
 494  *
 495  * @channel : the chanel to reserve space into.
 496  * @transport_data : specific transport data.
 497  * @buf_offset : offset of beginning of reserved slot
 498  * @slot_size : size of the reserved slot.
 499  */
 500 static inline void ltt_commit_slot(
 501                 struct ltt_channel_struct *channel,
 502                 void **transport_data,
 503                 long buf_offset,
 504                 size_t slot_size)
 505 {
 506         struct ltt_trace_struct *trace = channel->trace;
 507
 508         trace->ops->commit_slot(channel, transport_data, buf_offset, slot_size);
 509 }
 510
 511 /*
 512  * Control channels :
 513  * control/metadata
 514  * control/interrupts
 515  * control/...
 516  *
 517  * cpu channel :
 518  * cpu
 519  */
 520
 521 #define LTT_METADATA_CHANNEL            "metadata_state"
 522 #define LTT_UST_CHANNEL                 "ust"
 523
 524 #define LTT_FLIGHT_PREFIX       "flight-"
 525
 526 /* Tracer properties */
 527 //#define LTT_DEFAULT_SUBBUF_SIZE_LOW   65536
 528 #define LTT_DEFAULT_SUBBUF_SIZE_LOW     4096
 529 #define LTT_DEFAULT_N_SUBBUFS_LOW       2
 530 //#define LTT_DEFAULT_SUBBUF_SIZE_MED   262144
 531 #define LTT_DEFAULT_SUBBUF_SIZE_MED     4096
 532 #define LTT_DEFAULT_N_SUBBUFS_MED       2
 533 //#define LTT_DEFAULT_SUBBUF_SIZE_HIGH  1048576
 534 #define LTT_DEFAULT_SUBBUF_SIZE_HIGH    4096
 535 #define LTT_DEFAULT_N_SUBBUFS_HIGH      2
 536 #define LTT_TRACER_MAGIC_NUMBER         0x00D6B7ED
 537 #define LTT_TRACER_VERSION_MAJOR        2
 538 #define LTT_TRACER_VERSION_MINOR        3
 539
 540 /*
 541  * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
 542  * nearly full buffer. User space won't use this last amount of space when in
 543  * blocking mode. This space also includes the event header that would be
 544  * written by this user space event.
 545  */
 546 #define LTT_RESERVE_CRITICAL            4096
 547
 548 /* Register and unregister function pointers */
 549
 550 enum ltt_module_function {
 551         LTT_FUNCTION_RUN_FILTER,
 552         LTT_FUNCTION_FILTER_CONTROL,
 553         LTT_FUNCTION_STATEDUMP
 554 };
 555
 556 void ltt_transport_register(struct ltt_transport *transport);
 557 void ltt_transport_unregister(struct ltt_transport *transport);
 558
 559 /* Exported control function */
 560
 561 union ltt_control_args {
 562         struct {
 563                 enum trace_mode mode;
 564                 unsigned int subbuf_size_low;
 565                 unsigned int n_subbufs_low;
 566                 unsigned int subbuf_size_med;
 567                 unsigned int n_subbufs_med;
 568                 unsigned int subbuf_size_high;
 569                 unsigned int n_subbufs_high;
 570         } new_trace;
 571 };
 572
 573 int _ltt_trace_setup(const char *trace_name);
 574 int ltt_trace_setup(const char *trace_name);
 575 struct ltt_trace_struct *_ltt_trace_find_setup(const char *trace_name);
 576 int ltt_trace_set_type(const char *trace_name, const char *trace_type);
 577 int ltt_trace_set_channel_subbufsize(const char *trace_name,
 578                 const char *channel_name, unsigned int size);
 579 int ltt_trace_set_channel_subbufcount(const char *trace_name,
 580                 const char *channel_name, unsigned int cnt);
 581 int ltt_trace_set_channel_enable(const char *trace_name,
 582                 const char *channel_name, unsigned int enable);
 583 int ltt_trace_set_channel_overwrite(const char *trace_name,
 584                 const char *channel_name, unsigned int overwrite);
 585 int ltt_trace_alloc(const char *trace_name);
 586 int ltt_trace_destroy(const char *trace_name);
 587 int ltt_trace_start(const char *trace_name);
 588 int ltt_trace_stop(const char *trace_name);
 589
 590 enum ltt_filter_control_msg {
 591         LTT_FILTER_DEFAULT_ACCEPT,
 592         LTT_FILTER_DEFAULT_REJECT
 593 };
 594
 595 extern int ltt_filter_control(enum ltt_filter_control_msg msg,
 596                 const char *trace_name);
 597
 598 extern struct dentry *get_filter_root(void);
 599
 600 void ltt_write_trace_header(struct ltt_trace_struct *trace,
 601                 struct ltt_subbuffer_header *header);
 602 extern void ltt_buffer_destroy(struct ltt_channel_struct *ltt_chan);
 603
 604 void ltt_core_register(int (*function)(u8, void *));
 605
 606 void ltt_core_unregister(void);
 607
 608 void ltt_release_trace(struct kref *kref);
 609 void ltt_release_transport(struct kref *kref);
 610
 611 extern int ltt_probe_register(struct ltt_available_probe *pdata);
 612 extern int ltt_probe_unregister(struct ltt_available_probe *pdata);
 613 extern int ltt_marker_connect(const char *channel, const char *mname,
 614                 const char *pname);
 615 extern int ltt_marker_disconnect(const char *channel, const char *mname,
 616                 const char *pname);
 617 extern void ltt_dump_marker_state(struct ltt_trace_struct *trace);
 618
 619 void ltt_lock_traces(void);
 620 void ltt_unlock_traces(void);
 621
 622 struct ltt_trace_struct *_ltt_trace_find(const char *trace_name);
 623
 624 #endif /* _LTT_TRACER_H */