Fix: vmalloc wrapper on kernel < 2.6.38
[lttng-modules.git] / lttng-ring-buffer-metadata-client.h
CommitLineData
881833e3 1/*
a90917c3 2 * lttng-ring-buffer-client.h
881833e3 3 *
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4 * LTTng lib ring buffer client template.
5 *
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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
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21 */
22
23#include <linux/module.h>
24#include <linux/types.h>
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25#include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
26#include <lttng-events.h>
27#include <lttng-tracer.h>
881833e3 28
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29static struct lttng_transport lttng_relay_transport;
30
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31struct metadata_packet_header {
32 uint32_t magic; /* 0x75D11D57 */
1ec3f75a 33 uint8_t uuid[16]; /* Unique Universal Identifier */
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34 uint32_t checksum; /* 0 if unused */
35 uint32_t content_size; /* in bits */
36 uint32_t packet_size; /* in bits */
37 uint8_t compression_scheme; /* 0 if unused */
38 uint8_t encryption_scheme; /* 0 if unused */
39 uint8_t checksum_scheme; /* 0 if unused */
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40 uint8_t major; /* CTF spec major version number */
41 uint8_t minor; /* CTF spec minor version number */
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42 uint8_t header_end[0];
43};
44
45struct metadata_record_header {
46 uint8_t header_end[0]; /* End of header */
47};
48
49static const struct lib_ring_buffer_config client_config;
50
51static inline
52u64 lib_ring_buffer_clock_read(struct channel *chan)
53{
54 return 0;
55}
56
57static inline
c1cc82b8 58size_t record_header_size(const struct lib_ring_buffer_config *config,
881833e3 59 struct channel *chan, size_t offset,
64c796d8 60 size_t *pre_header_padding,
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61 struct lib_ring_buffer_ctx *ctx,
62 void *client_ctx)
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63{
64 return 0;
65}
66
bbd023d6 67#include <wrapper/ringbuffer/api.h>
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68
69static u64 client_ring_buffer_clock_read(struct channel *chan)
70{
71 return 0;
72}
73
74static
75size_t client_record_header_size(const struct lib_ring_buffer_config *config,
76 struct channel *chan, size_t offset,
881833e3 77 size_t *pre_header_padding,
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78 struct lib_ring_buffer_ctx *ctx,
79 void *client_ctx)
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80{
81 return 0;
82}
83
84/**
85 * client_packet_header_size - called on buffer-switch to a new sub-buffer
86 *
87 * Return header size without padding after the structure. Don't use packed
88 * structure because gcc generates inefficient code on some architectures
89 * (powerpc, mips..)
90 */
91static size_t client_packet_header_size(void)
92{
93 return offsetof(struct metadata_packet_header, header_end);
94}
95
96static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
97 unsigned int subbuf_idx)
98{
99 struct channel *chan = buf->backend.chan;
100 struct metadata_packet_header *header =
101 (struct metadata_packet_header *)
102 lib_ring_buffer_offset_address(&buf->backend,
103 subbuf_idx * chan->backend.subbuf_size);
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104 struct lttng_metadata_cache *metadata_cache =
105 channel_get_private(chan);
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106
107 header->magic = TSDL_MAGIC_NUMBER;
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108 memcpy(header->uuid, metadata_cache->uuid.b,
109 sizeof(metadata_cache->uuid));
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110 header->checksum = 0; /* 0 if unused */
111 header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
112 header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
113 header->compression_scheme = 0; /* 0 if unused */
114 header->encryption_scheme = 0; /* 0 if unused */
115 header->checksum_scheme = 0; /* 0 if unused */
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116 header->major = CTF_SPEC_MAJOR;
117 header->minor = CTF_SPEC_MINOR;
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118}
119
120/*
121 * offset is assumed to never be 0 here : never deliver a completely empty
122 * subbuffer. data_size is between 1 and subbuf_size.
123 */
124static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
125 unsigned int subbuf_idx, unsigned long data_size)
126{
127 struct channel *chan = buf->backend.chan;
d793d5e1 128 struct metadata_packet_header *header =
1ec3f75a 129 (struct metadata_packet_header *)
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130 lib_ring_buffer_offset_address(&buf->backend,
131 subbuf_idx * chan->backend.subbuf_size);
132 unsigned long records_lost = 0;
133
134 header->content_size = data_size * CHAR_BIT; /* in bits */
135 header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
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136 /*
137 * We do not care about the records lost count, because the metadata
138 * channel waits and retry.
139 */
140 (void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
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141 records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
142 records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
143 WARN_ON_ONCE(records_lost != 0);
144}
145
146static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
147 int cpu, const char *name)
148{
149 return 0;
150}
151
152static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
153{
154}
155
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156static int client_timestamp_begin(const struct lib_ring_buffer_config *config,
157 struct lib_ring_buffer *buf, uint64_t *timestamp_begin)
158{
159 return -ENOSYS;
160}
161
162static int client_timestamp_end(const struct lib_ring_buffer_config *config,
163 struct lib_ring_buffer *bufb,
164 uint64_t *timestamp_end)
165{
166 return -ENOSYS;
167}
168
169static int client_events_discarded(const struct lib_ring_buffer_config *config,
170 struct lib_ring_buffer *bufb,
171 uint64_t *events_discarded)
172{
173 return -ENOSYS;
174}
175
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176static int client_current_timestamp(const struct lib_ring_buffer_config *config,
177 struct lib_ring_buffer *bufb,
178 uint64_t *ts)
179{
180 return -ENOSYS;
181}
182
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183static int client_content_size(const struct lib_ring_buffer_config *config,
184 struct lib_ring_buffer *bufb,
185 uint64_t *content_size)
186{
187 return -ENOSYS;
188}
189
190static int client_packet_size(const struct lib_ring_buffer_config *config,
191 struct lib_ring_buffer *bufb,
192 uint64_t *packet_size)
193{
194 return -ENOSYS;
195}
196
197static int client_stream_id(const struct lib_ring_buffer_config *config,
198 struct lib_ring_buffer *bufb,
199 uint64_t *stream_id)
200{
201 return -ENOSYS;
202}
203
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204static int client_sequence_number(const struct lib_ring_buffer_config *config,
205 struct lib_ring_buffer *bufb,
206 uint64_t *seq)
207{
208 return -ENOSYS;
209}
210
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211static
212int client_instance_id(const struct lib_ring_buffer_config *config,
213 struct lib_ring_buffer *bufb,
214 uint64_t *id)
215{
216 return -ENOSYS;
217}
218
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219static const struct lib_ring_buffer_config client_config = {
220 .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
221 .cb.record_header_size = client_record_header_size,
222 .cb.subbuffer_header_size = client_packet_header_size,
223 .cb.buffer_begin = client_buffer_begin,
224 .cb.buffer_end = client_buffer_end,
225 .cb.buffer_create = client_buffer_create,
226 .cb.buffer_finalize = client_buffer_finalize,
227
228 .tsc_bits = 0,
229 .alloc = RING_BUFFER_ALLOC_GLOBAL,
230 .sync = RING_BUFFER_SYNC_GLOBAL,
231 .mode = RING_BUFFER_MODE_TEMPLATE,
232 .backend = RING_BUFFER_PAGE,
2db1399a 233 .output = RING_BUFFER_OUTPUT_TEMPLATE,
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234 .oops = RING_BUFFER_OOPS_CONSISTENCY,
235 .ipi = RING_BUFFER_IPI_BARRIER,
236 .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
237};
238
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239static
240void release_priv_ops(void *priv_ops)
241{
242 module_put(THIS_MODULE);
243}
244
245static
246void lttng_channel_destroy(struct channel *chan)
247{
248 channel_destroy(chan);
249}
250
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251static
252struct channel *_channel_create(const char *name,
a90917c3 253 struct lttng_channel *lttng_chan, void *buf_addr,
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254 size_t subbuf_size, size_t num_subbuf,
255 unsigned int switch_timer_interval,
256 unsigned int read_timer_interval)
257{
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258 struct channel *chan;
259
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260 chan = channel_create(&client_config, name,
261 lttng_chan->session->metadata_cache, buf_addr,
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262 subbuf_size, num_subbuf, switch_timer_interval,
263 read_timer_interval);
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264 if (chan) {
265 /*
266 * Ensure this module is not unloaded before we finish
267 * using lttng_relay_transport.ops.
268 */
269 if (!try_module_get(THIS_MODULE)) {
270 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
271 goto error;
272 }
273 chan->backend.priv_ops = &lttng_relay_transport.ops;
274 chan->backend.release_priv_ops = release_priv_ops;
275 }
276 return chan;
881833e3 277
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278error:
279 lttng_channel_destroy(chan);
280 return NULL;
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281}
282
283static
a90917c3 284struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan)
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285{
286 struct lib_ring_buffer *buf;
881833e3 287
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288 buf = channel_get_ring_buffer(&client_config, chan, 0);
289 if (!lib_ring_buffer_open_read(buf))
290 return buf;
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291 return NULL;
292}
293
f71ecafa 294static
a90917c3 295int lttng_buffer_has_read_closed_stream(struct channel *chan)
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296{
297 struct lib_ring_buffer *buf;
298 int cpu;
299
300 for_each_channel_cpu(cpu, chan) {
301 buf = channel_get_ring_buffer(&client_config, chan, cpu);
302 if (!atomic_long_read(&buf->active_readers))
303 return 1;
304 }
305 return 0;
306}
307
881833e3 308static
a90917c3 309void lttng_buffer_read_close(struct lib_ring_buffer *buf)
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310{
311 lib_ring_buffer_release_read(buf);
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312}
313
c099397a 314static
a90917c3 315int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
881833e3 316{
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317 int ret;
318
cc62f29e 319 ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
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320 if (ret)
321 return ret;
322 lib_ring_buffer_backend_get_pages(&client_config, ctx,
323 &ctx->backend_pages);
324 return 0;
325
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326}
327
c099397a 328static
a90917c3 329void lttng_event_commit(struct lib_ring_buffer_ctx *ctx)
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330{
331 lib_ring_buffer_commit(&client_config, ctx);
332}
333
c099397a 334static
a90917c3 335void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
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336 size_t len)
337{
338 lib_ring_buffer_write(&client_config, ctx, src, len);
339}
340
4ea00e4f 341static
a90917c3 342void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
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343 const void __user *src, size_t len)
344{
7b8ea3a5 345 lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
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346}
347
58aa5d24 348static
a90917c3 349void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
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350 int c, size_t len)
351{
352 lib_ring_buffer_memset(&client_config, ctx, c, len);
353}
354
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355static
356void lttng_event_strcpy(struct lib_ring_buffer_ctx *ctx, const char *src,
357 size_t len)
358{
359 lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
360}
361
1ec3f75a 362static
a90917c3 363size_t lttng_packet_avail_size(struct channel *chan)
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364
365{
366 unsigned long o_begin;
367 struct lib_ring_buffer *buf;
368
369 buf = chan->backend.buf; /* Only for global buffer ! */
370 o_begin = v_read(&client_config, &buf->offset);
371 if (subbuf_offset(o_begin, chan) != 0) {
372 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
373 } else {
374 return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
375 - sizeof(struct metadata_packet_header);
376 }
377}
378
c099397a 379static
a90917c3 380wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu)
c099397a 381{
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382 struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
383 chan, cpu);
384 return &buf->write_wait;
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385}
386
387static
a90917c3 388wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan)
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389{
390 return &chan->hp_wait;
391}
392
393static
a90917c3 394int lttng_is_finalized(struct channel *chan)
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395{
396 return lib_ring_buffer_channel_is_finalized(chan);
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397}
398
254ec7bc 399static
a90917c3 400int lttng_is_disabled(struct channel *chan)
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401{
402 return lib_ring_buffer_channel_is_disabled(chan);
403}
404
a90917c3 405static struct lttng_transport lttng_relay_transport = {
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406 .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
407 .owner = THIS_MODULE,
408 .ops = {
409 .channel_create = _channel_create,
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410 .channel_destroy = lttng_channel_destroy,
411 .buffer_read_open = lttng_buffer_read_open,
f71ecafa 412 .buffer_has_read_closed_stream =
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413 lttng_buffer_has_read_closed_stream,
414 .buffer_read_close = lttng_buffer_read_close,
415 .event_reserve = lttng_event_reserve,
416 .event_commit = lttng_event_commit,
417 .event_write_from_user = lttng_event_write_from_user,
418 .event_memset = lttng_event_memset,
419 .event_write = lttng_event_write,
16f78f3a 420 .event_strcpy = lttng_event_strcpy,
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421 .packet_avail_size = lttng_packet_avail_size,
422 .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
423 .get_hp_wait_queue = lttng_get_hp_wait_queue,
424 .is_finalized = lttng_is_finalized,
425 .is_disabled = lttng_is_disabled,
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426 .timestamp_begin = client_timestamp_begin,
427 .timestamp_end = client_timestamp_end,
428 .events_discarded = client_events_discarded,
429 .content_size = client_content_size,
430 .packet_size = client_packet_size,
431 .stream_id = client_stream_id,
432 .current_timestamp = client_current_timestamp,
5b3cf4f9 433 .sequence_number = client_sequence_number,
5594698f 434 .instance_id = client_instance_id,
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435 },
436};
437
a90917c3 438static int __init lttng_ring_buffer_client_init(void)
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439{
440 /*
441 * This vmalloc sync all also takes care of the lib ring buffer
442 * vmalloc'd module pages when it is built as a module into LTTng.
443 */
444 wrapper_vmalloc_sync_all();
a90917c3 445 lttng_transport_register(&lttng_relay_transport);
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446 return 0;
447}
448
a90917c3 449module_init(lttng_ring_buffer_client_init);
881833e3 450
a90917c3 451static void __exit lttng_ring_buffer_client_exit(void)
881833e3 452{
a90917c3 453 lttng_transport_unregister(&lttng_relay_transport);
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454}
455
a90917c3 456module_exit(lttng_ring_buffer_client_exit);
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457
458MODULE_LICENSE("GPL and additional rights");
459MODULE_AUTHOR("Mathieu Desnoyers");
460MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
461 " client");
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