lttng-ring-buffer-client.h

   1 /*
   2  * lttng-ring-buffer-client.h
   3  *
   4  * LTTng lib ring buffer client template.
   5  *
   6  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/types.h>
  25 #include "lib/bitfield.h"
  26 #include "wrapper/vmalloc.h"    /* for wrapper_vmalloc_sync_all() */
  27 #include "wrapper/trace-clock.h"
  28 #include "lttng-events.h"
  29 #include "lttng-tracer.h"
  30 #include "wrapper/ringbuffer/frontend_types.h"
  31
  32 #define LTTNG_COMPACT_EVENT_BITS        5
  33 #define LTTNG_COMPACT_TSC_BITS          27
  34
  35 static struct lttng_transport lttng_relay_transport;
  36
  37 /*
  38  * Keep the natural field alignment for _each field_ within this structure if
  39  * you ever add/remove a field from this header. Packed attribute is not used
  40  * because gcc generates poor code on at least powerpc and mips. Don't ever
  41  * let gcc add padding between the structure elements.
  42  *
  43  * The guarantee we have with timestamps is that all the events in a
  44  * packet are included (inclusive) within the begin/end timestamps of
  45  * the packet. Another guarantee we have is that the "timestamp begin",
  46  * as well as the event timestamps, are monotonically increasing (never
  47  * decrease) when moving forward in a stream (physically). But this
  48  * guarantee does not apply to "timestamp end", because it is sampled at
  49  * commit time, which is not ordered with respect to space reservation.
  50  */
  51
  52 struct packet_header {
  53         /* Trace packet header */
  54         uint32_t magic;                 /*
  55                                          * Trace magic number.
  56                                          * contains endianness information.
  57                                          */
  58         uint8_t uuid[16];
  59         uint32_t stream_id;
  60
  61         struct {
  62                 /* Stream packet context */
  63                 uint64_t timestamp_begin;       /* Cycle count at subbuffer start */
  64                 uint64_t timestamp_end;         /* Cycle count at subbuffer end */
  65                 uint64_t content_size;          /* Size of data in subbuffer */
  66                 uint64_t packet_size;           /* Subbuffer size (include padding) */
  67                 unsigned long events_discarded; /*
  68                                                  * Events lost in this subbuffer since
  69                                                  * the beginning of the trace.
  70                                                  * (may overflow)
  71                                                  */
  72                 uint32_t cpu_id;                /* CPU id associated with stream */
  73                 uint8_t header_end;             /* End of header */
  74         } ctx;
  75 };
  76
  77
  78 static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
  79 {
  80         return trace_clock_read64();
  81 }
  82
  83 static inline
  84 size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx)
  85 {
  86         int i;
  87         size_t orig_offset = offset;
  88
  89         if (likely(!ctx))
  90                 return 0;
  91         offset += lib_ring_buffer_align(offset, ctx->largest_align);
  92         for (i = 0; i < ctx->nr_fields; i++)
  93                 offset += ctx->fields[i].get_size(offset);
  94         return offset - orig_offset;
  95 }
  96
  97 static inline
  98 void ctx_record(struct lib_ring_buffer_ctx *bufctx,
  99                 struct lttng_channel *chan,
 100                 struct lttng_ctx *ctx)
 101 {
 102         int i;
 103
 104         if (likely(!ctx))
 105                 return;
 106         lib_ring_buffer_align_ctx(bufctx, ctx->largest_align);
 107         for (i = 0; i < ctx->nr_fields; i++)
 108                 ctx->fields[i].record(&ctx->fields[i], bufctx, chan);
 109 }
 110
 111 /*
 112  * record_header_size - Calculate the header size and padding necessary.
 113  * @config: ring buffer instance configuration
 114  * @chan: channel
 115  * @offset: offset in the write buffer
 116  * @pre_header_padding: padding to add before the header (output)
 117  * @ctx: reservation context
 118  *
 119  * Returns the event header size (including padding).
 120  *
 121  * The payload must itself determine its own alignment from the biggest type it
 122  * contains.
 123  */
 124 static __inline__
 125 unsigned char record_header_size(const struct lib_ring_buffer_config *config,
 126                                  struct channel *chan, size_t offset,
 127                                  size_t *pre_header_padding,
 128                                  struct lib_ring_buffer_ctx *ctx)
 129 {
 130         struct lttng_channel *lttng_chan = channel_get_private(chan);
 131         struct lttng_event *event = ctx->priv;
 132         size_t orig_offset = offset;
 133         size_t padding;
 134
 135         switch (lttng_chan->header_type) {
 136         case 1: /* compact */
 137                 padding = lib_ring_buffer_align(offset, lttng_alignof(uint32_t));
 138                 offset += padding;
 139                 if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
 140                         offset += sizeof(uint32_t);     /* id and timestamp */
 141                 } else {
 142                         /* Minimum space taken by LTTNG_COMPACT_EVENT_BITS id */
 143                         offset += (LTTNG_COMPACT_EVENT_BITS + CHAR_BIT - 1) / CHAR_BIT;
 144                         /* Align extended struct on largest member */
 145                         offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
 146                         offset += sizeof(uint32_t);     /* id */
 147                         offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
 148                         offset += sizeof(uint64_t);     /* timestamp */
 149                 }
 150                 break;
 151         case 2: /* large */
 152                 padding = lib_ring_buffer_align(offset, lttng_alignof(uint16_t));
 153                 offset += padding;
 154                 offset += sizeof(uint16_t);
 155                 if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
 156                         offset += lib_ring_buffer_align(offset, lttng_alignof(uint32_t));
 157                         offset += sizeof(uint32_t);     /* timestamp */
 158                 } else {
 159                         /* Align extended struct on largest member */
 160                         offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
 161                         offset += sizeof(uint32_t);     /* id */
 162                         offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
 163                         offset += sizeof(uint64_t);     /* timestamp */
 164                 }
 165                 break;
 166         default:
 167                 padding = 0;
 168                 WARN_ON_ONCE(1);
 169         }
 170         offset += ctx_get_size(offset, event->ctx);
 171         offset += ctx_get_size(offset, lttng_chan->ctx);
 172
 173         *pre_header_padding = padding;
 174         return offset - orig_offset;
 175 }
 176
 177 #include "wrapper/ringbuffer/api.h"
 178
 179 static
 180 void lttng_write_event_header_slow(const struct lib_ring_buffer_config *config,
 181                                  struct lib_ring_buffer_ctx *ctx,
 182                                  uint32_t event_id);
 183
 184 /*
 185  * lttng_write_event_header
 186  *
 187  * Writes the event header to the offset (already aligned on 32-bits).
 188  *
 189  * @config: ring buffer instance configuration
 190  * @ctx: reservation context
 191  * @event_id: event ID
 192  */
 193 static __inline__
 194 void lttng_write_event_header(const struct lib_ring_buffer_config *config,
 195                             struct lib_ring_buffer_ctx *ctx,
 196                             uint32_t event_id)
 197 {
 198         struct lttng_channel *lttng_chan = channel_get_private(ctx->chan);
 199         struct lttng_event *event = ctx->priv;
 200
 201         if (unlikely(ctx->rflags))
 202                 goto slow_path;
 203
 204         switch (lttng_chan->header_type) {
 205         case 1: /* compact */
 206         {
 207                 uint32_t id_time = 0;
 208
 209                 bt_bitfield_write(&id_time, uint32_t,
 210                                 0,
 211                                 LTTNG_COMPACT_EVENT_BITS,
 212                                 event_id);
 213                 bt_bitfield_write(&id_time, uint32_t,
 214                                 LTTNG_COMPACT_EVENT_BITS,
 215                                 LTTNG_COMPACT_TSC_BITS,
 216                                 ctx->tsc);
 217                 lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
 218                 break;
 219         }
 220         case 2: /* large */
 221         {
 222                 uint32_t timestamp = (uint32_t) ctx->tsc;
 223                 uint16_t id = event_id;
 224
 225                 lib_ring_buffer_write(config, ctx, &id, sizeof(id));
 226                 lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint32_t));
 227                 lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
 228                 break;
 229         }
 230         default:
 231                 WARN_ON_ONCE(1);
 232         }
 233
 234         ctx_record(ctx, lttng_chan, lttng_chan->ctx);
 235         ctx_record(ctx, lttng_chan, event->ctx);
 236         lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
 237
 238         return;
 239
 240 slow_path:
 241         lttng_write_event_header_slow(config, ctx, event_id);
 242 }
 243
 244 static
 245 void lttng_write_event_header_slow(const struct lib_ring_buffer_config *config,
 246                                  struct lib_ring_buffer_ctx *ctx,
 247                                  uint32_t event_id)
 248 {
 249         struct lttng_channel *lttng_chan = channel_get_private(ctx->chan);
 250         struct lttng_event *event = ctx->priv;
 251
 252         switch (lttng_chan->header_type) {
 253         case 1: /* compact */
 254                 if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
 255                         uint32_t id_time = 0;
 256
 257                         bt_bitfield_write(&id_time, uint32_t,
 258                                         0,
 259                                         LTTNG_COMPACT_EVENT_BITS,
 260                                         event_id);
 261                         bt_bitfield_write(&id_time, uint32_t,
 262                                         LTTNG_COMPACT_EVENT_BITS,
 263                                         LTTNG_COMPACT_TSC_BITS, ctx->tsc);
 264                         lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
 265                 } else {
 266                         uint8_t id = 0;
 267                         uint64_t timestamp = ctx->tsc;
 268
 269                         bt_bitfield_write(&id, uint8_t,
 270                                         0,
 271                                         LTTNG_COMPACT_EVENT_BITS,
 272                                         31);
 273                         lib_ring_buffer_write(config, ctx, &id, sizeof(id));
 274                         /* Align extended struct on largest member */
 275                         lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
 276                         lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
 277                         lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
 278                         lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
 279                 }
 280                 break;
 281         case 2: /* large */
 282         {
 283                 if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
 284                         uint32_t timestamp = (uint32_t) ctx->tsc;
 285                         uint16_t id = event_id;
 286
 287                         lib_ring_buffer_write(config, ctx, &id, sizeof(id));
 288                         lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint32_t));
 289                         lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
 290                 } else {
 291                         uint16_t id = 65535;
 292                         uint64_t timestamp = ctx->tsc;
 293
 294                         lib_ring_buffer_write(config, ctx, &id, sizeof(id));
 295                         /* Align extended struct on largest member */
 296                         lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
 297                         lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
 298                         lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
 299                         lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
 300                 }
 301                 break;
 302         }
 303         default:
 304                 WARN_ON_ONCE(1);
 305         }
 306         ctx_record(ctx, lttng_chan, lttng_chan->ctx);
 307         ctx_record(ctx, lttng_chan, event->ctx);
 308         lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
 309 }
 310
 311 static const struct lib_ring_buffer_config client_config;
 312
 313 static u64 client_ring_buffer_clock_read(struct channel *chan)
 314 {
 315         return lib_ring_buffer_clock_read(chan);
 316 }
 317
 318 static
 319 size_t client_record_header_size(const struct lib_ring_buffer_config *config,
 320                                  struct channel *chan, size_t offset,
 321                                  size_t *pre_header_padding,
 322                                  struct lib_ring_buffer_ctx *ctx)
 323 {
 324         return record_header_size(config, chan, offset,
 325                                   pre_header_padding, ctx);
 326 }
 327
 328 /**
 329  * client_packet_header_size - called on buffer-switch to a new sub-buffer
 330  *
 331  * Return header size without padding after the structure. Don't use packed
 332  * structure because gcc generates inefficient code on some architectures
 333  * (powerpc, mips..)
 334  */
 335 static size_t client_packet_header_size(void)
 336 {
 337         return offsetof(struct packet_header, ctx.header_end);
 338 }
 339
 340 static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
 341                                 unsigned int subbuf_idx)
 342 {
 343         struct channel *chan = buf->backend.chan;
 344         struct packet_header *header =
 345                 (struct packet_header *)
 346                         lib_ring_buffer_offset_address(&buf->backend,
 347                                 subbuf_idx * chan->backend.subbuf_size);
 348         struct lttng_channel *lttng_chan = channel_get_private(chan);
 349         struct lttng_session *session = lttng_chan->session;
 350
 351         header->magic = CTF_MAGIC_NUMBER;
 352         memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
 353         header->stream_id = lttng_chan->id;
 354         header->ctx.timestamp_begin = tsc;
 355         header->ctx.timestamp_end = 0;
 356         header->ctx.content_size = ~0ULL; /* for debugging */
 357         header->ctx.packet_size = ~0ULL;
 358         header->ctx.events_discarded = 0;
 359         header->ctx.cpu_id = buf->backend.cpu;
 360 }
 361
 362 /*
 363  * offset is assumed to never be 0 here : never deliver a completely empty
 364  * subbuffer. data_size is between 1 and subbuf_size.
 365  */
 366 static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
 367                               unsigned int subbuf_idx, unsigned long data_size)
 368 {
 369         struct channel *chan = buf->backend.chan;
 370         struct packet_header *header =
 371                 (struct packet_header *)
 372                         lib_ring_buffer_offset_address(&buf->backend,
 373                                 subbuf_idx * chan->backend.subbuf_size);
 374         unsigned long records_lost = 0;
 375
 376         header->ctx.timestamp_end = tsc;
 377         header->ctx.content_size =
 378                 (uint64_t) data_size * CHAR_BIT;                /* in bits */
 379         header->ctx.packet_size =
 380                 (uint64_t) PAGE_ALIGN(data_size) * CHAR_BIT;    /* in bits */
 381         records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
 382         records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
 383         records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
 384         header->ctx.events_discarded = records_lost;
 385 }
 386
 387 static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
 388                                 int cpu, const char *name)
 389 {
 390         return 0;
 391 }
 392
 393 static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
 394 {
 395 }
 396
 397 static struct packet_header *client_packet_header(
 398                 const struct lib_ring_buffer_config *config,
 399                 struct lib_ring_buffer *buf)
 400 {
 401         return lib_ring_buffer_read_offset_address(&buf->backend, 0);
 402 }
 403
 404 static int client_timestamp_begin(const struct lib_ring_buffer_config *config,
 405                 struct lib_ring_buffer *buf,
 406                 uint64_t *timestamp_begin)
 407 {
 408         struct packet_header *header = client_packet_header(config, buf);
 409         *timestamp_begin = header->ctx.timestamp_begin;
 410
 411         return 0;
 412 }
 413
 414 static int client_timestamp_end(const struct lib_ring_buffer_config *config,
 415                         struct lib_ring_buffer *buf,
 416                         uint64_t *timestamp_end)
 417 {
 418         struct packet_header *header = client_packet_header(config, buf);
 419         *timestamp_end = header->ctx.timestamp_end;
 420
 421         return 0;
 422 }
 423
 424 static int client_events_discarded(const struct lib_ring_buffer_config *config,
 425                         struct lib_ring_buffer *buf,
 426                         uint64_t *events_discarded)
 427 {
 428         struct packet_header *header = client_packet_header(config, buf);
 429         *events_discarded = header->ctx.events_discarded;
 430
 431         return 0;
 432 }
 433
 434 static int client_content_size(const struct lib_ring_buffer_config *config,
 435                         struct lib_ring_buffer *buf,
 436                         uint64_t *content_size)
 437 {
 438         struct packet_header *header = client_packet_header(config, buf);
 439         *content_size = header->ctx.content_size;
 440
 441         return 0;
 442 }
 443
 444 static int client_packet_size(const struct lib_ring_buffer_config *config,
 445                         struct lib_ring_buffer *buf,
 446                         uint64_t *packet_size)
 447 {
 448         struct packet_header *header = client_packet_header(config, buf);
 449         *packet_size = header->ctx.packet_size;
 450
 451         return 0;
 452 }
 453
 454 static int client_stream_id(const struct lib_ring_buffer_config *config,
 455                         struct lib_ring_buffer *buf,
 456                         uint64_t *stream_id)
 457 {
 458         struct packet_header *header = client_packet_header(config, buf);
 459         *stream_id = header->stream_id;
 460
 461         return 0;
 462 }
 463
 464 static int client_current_timestamp(const struct lib_ring_buffer_config *config,
 465                 struct lib_ring_buffer *bufb,
 466                 uint64_t *ts)
 467 {
 468         *ts = config->cb.ring_buffer_clock_read(bufb->backend.chan);
 469
 470         return 0;
 471 }
 472
 473 static const struct lib_ring_buffer_config client_config = {
 474         .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
 475         .cb.record_header_size = client_record_header_size,
 476         .cb.subbuffer_header_size = client_packet_header_size,
 477         .cb.buffer_begin = client_buffer_begin,
 478         .cb.buffer_end = client_buffer_end,
 479         .cb.buffer_create = client_buffer_create,
 480         .cb.buffer_finalize = client_buffer_finalize,
 481
 482         .tsc_bits = LTTNG_COMPACT_TSC_BITS,
 483         .alloc = RING_BUFFER_ALLOC_PER_CPU,
 484         .sync = RING_BUFFER_SYNC_PER_CPU,
 485         .mode = RING_BUFFER_MODE_TEMPLATE,
 486         .backend = RING_BUFFER_PAGE,
 487         .output = RING_BUFFER_OUTPUT_TEMPLATE,
 488         .oops = RING_BUFFER_OOPS_CONSISTENCY,
 489         .ipi = RING_BUFFER_IPI_BARRIER,
 490         .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
 491 };
 492
 493 static
 494 void release_priv_ops(void *priv_ops)
 495 {
 496         module_put(THIS_MODULE);
 497 }
 498
 499 static
 500 void lttng_channel_destroy(struct channel *chan)
 501 {
 502         channel_destroy(chan);
 503 }
 504
 505 static
 506 struct channel *_channel_create(const char *name,
 507                                 struct lttng_channel *lttng_chan, void *buf_addr,
 508                                 size_t subbuf_size, size_t num_subbuf,
 509                                 unsigned int switch_timer_interval,
 510                                 unsigned int read_timer_interval)
 511 {
 512         struct channel *chan;
 513
 514         chan = channel_create(&client_config, name, lttng_chan, buf_addr,
 515                               subbuf_size, num_subbuf, switch_timer_interval,
 516                               read_timer_interval);
 517         if (chan) {
 518                 /*
 519                  * Ensure this module is not unloaded before we finish
 520                  * using lttng_relay_transport.ops.
 521                  */
 522                 if (!try_module_get(THIS_MODULE)) {
 523                         printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 524                         goto error;
 525                 }
 526                 chan->backend.priv_ops = &lttng_relay_transport.ops;
 527                 chan->backend.release_priv_ops = release_priv_ops;
 528         }
 529         return chan;
 530
 531 error:
 532         lttng_channel_destroy(chan);
 533         return NULL;
 534 }
 535
 536 static
 537 struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan)
 538 {
 539         struct lib_ring_buffer *buf;
 540         int cpu;
 541
 542         for_each_channel_cpu(cpu, chan) {
 543                 buf = channel_get_ring_buffer(&client_config, chan, cpu);
 544                 if (!lib_ring_buffer_open_read(buf))
 545                         return buf;
 546         }
 547         return NULL;
 548 }
 549
 550 static
 551 int lttng_buffer_has_read_closed_stream(struct channel *chan)
 552 {
 553         struct lib_ring_buffer *buf;
 554         int cpu;
 555
 556         for_each_channel_cpu(cpu, chan) {
 557                 buf = channel_get_ring_buffer(&client_config, chan, cpu);
 558                 if (!atomic_long_read(&buf->active_readers))
 559                         return 1;
 560         }
 561         return 0;
 562 }
 563
 564 static
 565 void lttng_buffer_read_close(struct lib_ring_buffer *buf)
 566 {
 567         lib_ring_buffer_release_read(buf);
 568 }
 569
 570 static
 571 int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx,
 572                       uint32_t event_id)
 573 {
 574         struct lttng_channel *lttng_chan = channel_get_private(ctx->chan);
 575         int ret, cpu;
 576
 577         cpu = lib_ring_buffer_get_cpu(&client_config);
 578         if (cpu < 0)
 579                 return -EPERM;
 580         ctx->cpu = cpu;
 581
 582         switch (lttng_chan->header_type) {
 583         case 1: /* compact */
 584                 if (event_id > 30)
 585                         ctx->rflags |= LTTNG_RFLAG_EXTENDED;
 586                 break;
 587         case 2: /* large */
 588                 if (event_id > 65534)
 589                         ctx->rflags |= LTTNG_RFLAG_EXTENDED;
 590                 break;
 591         default:
 592                 WARN_ON_ONCE(1);
 593         }
 594
 595         ret = lib_ring_buffer_reserve(&client_config, ctx);
 596         if (ret)
 597                 goto put;
 598         lttng_write_event_header(&client_config, ctx, event_id);
 599         return 0;
 600 put:
 601         lib_ring_buffer_put_cpu(&client_config);
 602         return ret;
 603 }
 604
 605 static
 606 void lttng_event_commit(struct lib_ring_buffer_ctx *ctx)
 607 {
 608         lib_ring_buffer_commit(&client_config, ctx);
 609         lib_ring_buffer_put_cpu(&client_config);
 610 }
 611
 612 static
 613 void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
 614                      size_t len)
 615 {
 616         lib_ring_buffer_write(&client_config, ctx, src, len);
 617 }
 618
 619 static
 620 void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
 621                                const void __user *src, size_t len)
 622 {
 623         lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
 624 }
 625
 626 static
 627 void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
 628                 int c, size_t len)
 629 {
 630         lib_ring_buffer_memset(&client_config, ctx, c, len);
 631 }
 632
 633 static
 634 void lttng_event_strcpy(struct lib_ring_buffer_ctx *ctx, const char *src,
 635                 size_t len)
 636 {
 637         lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
 638 }
 639
 640 static
 641 void lttng_event_strcpy_from_user(struct lib_ring_buffer_ctx *ctx,
 642                 const char __user *src, size_t len)
 643 {
 644         lib_ring_buffer_strcpy_from_user_inatomic(&client_config, ctx, src,
 645                         len, '#');
 646 }
 647
 648 static
 649 wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu)
 650 {
 651         struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
 652                                         chan, cpu);
 653         return &buf->write_wait;
 654 }
 655
 656 static
 657 wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan)
 658 {
 659         return &chan->hp_wait;
 660 }
 661
 662 static
 663 int lttng_is_finalized(struct channel *chan)
 664 {
 665         return lib_ring_buffer_channel_is_finalized(chan);
 666 }
 667
 668 static
 669 int lttng_is_disabled(struct channel *chan)
 670 {
 671         return lib_ring_buffer_channel_is_disabled(chan);
 672 }
 673
 674 static struct lttng_transport lttng_relay_transport = {
 675         .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
 676         .owner = THIS_MODULE,
 677         .ops = {
 678                 .channel_create = _channel_create,
 679                 .channel_destroy = lttng_channel_destroy,
 680                 .buffer_read_open = lttng_buffer_read_open,
 681                 .buffer_has_read_closed_stream =
 682                         lttng_buffer_has_read_closed_stream,
 683                 .buffer_read_close = lttng_buffer_read_close,
 684                 .event_reserve = lttng_event_reserve,
 685                 .event_commit = lttng_event_commit,
 686                 .event_write = lttng_event_write,
 687                 .event_write_from_user = lttng_event_write_from_user,
 688                 .event_memset = lttng_event_memset,
 689                 .event_strcpy = lttng_event_strcpy,
 690                 .event_strcpy_from_user = lttng_event_strcpy_from_user,
 691                 .packet_avail_size = NULL,      /* Would be racy anyway */
 692                 .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
 693                 .get_hp_wait_queue = lttng_get_hp_wait_queue,
 694                 .is_finalized = lttng_is_finalized,
 695                 .is_disabled = lttng_is_disabled,
 696                 .timestamp_begin = client_timestamp_begin,
 697                 .timestamp_end = client_timestamp_end,
 698                 .events_discarded = client_events_discarded,
 699                 .content_size = client_content_size,
 700                 .packet_size = client_packet_size,
 701                 .stream_id = client_stream_id,
 702                 .current_timestamp = client_current_timestamp,
 703         },
 704 };
 705
 706 static int __init lttng_ring_buffer_client_init(void)
 707 {
 708         /*
 709          * This vmalloc sync all also takes care of the lib ring buffer
 710          * vmalloc'd module pages when it is built as a module into LTTng.
 711          */
 712         wrapper_vmalloc_sync_all();
 713         lttng_transport_register(&lttng_relay_transport);
 714         return 0;
 715 }
 716
 717 module_init(lttng_ring_buffer_client_init);
 718
 719 static void __exit lttng_ring_buffer_client_exit(void)
 720 {
 721         lttng_transport_unregister(&lttng_relay_transport);
 722 }
 723
 724 module_exit(lttng_ring_buffer_client_exit);
 725
 726 MODULE_LICENSE("GPL and additional rights");
 727 MODULE_AUTHOR("Mathieu Desnoyers");
 728 MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
 729                    " client");