Commit | Line | Data |
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7514523f | 1 | /* |
3d084699 | 2 | * ltt-ring-buffer-client.h |
7514523f MD |
3 | * |
4 | * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
3d084699 | 6 | * LTTng lib ring buffer client template. |
7514523f MD |
7 | * |
8 | * Dual LGPL v2.1/GPL v2 license. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
c0e31d2e | 12 | #include <linux/types.h> |
9115fbdc | 13 | #include "lib/bitfield.h" |
b13f3ebe | 14 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ |
f3bc08c5 | 15 | #include "wrapper/trace-clock.h" |
c0e31d2e | 16 | #include "ltt-events.h" |
7514523f | 17 | #include "ltt-tracer.h" |
9115fbdc | 18 | #include "wrapper/ringbuffer/frontend_types.h" |
7514523f | 19 | |
d793d5e1 MD |
20 | /* |
21 | * Keep the natural field alignment for _each field_ within this structure if | |
22 | * you ever add/remove a field from this header. Packed attribute is not used | |
23 | * because gcc generates poor code on at least powerpc and mips. Don't ever | |
24 | * let gcc add padding between the structure elements. | |
25 | */ | |
9115fbdc | 26 | |
d793d5e1 | 27 | struct packet_header { |
9115fbdc | 28 | /* Trace packet header */ |
d793d5e1 MD |
29 | uint32_t magic; /* |
30 | * Trace magic number. | |
31 | * contains endianness information. | |
32 | */ | |
1ec3f75a | 33 | uint8_t uuid[16]; |
d793d5e1 | 34 | uint32_t stream_id; |
9115fbdc MD |
35 | |
36 | struct { | |
37 | /* Stream packet context */ | |
38 | uint64_t timestamp_begin; /* Cycle count at subbuffer start */ | |
39 | uint64_t timestamp_end; /* Cycle count at subbuffer end */ | |
40 | uint32_t events_discarded; /* | |
41 | * Events lost in this subbuffer since | |
42 | * the beginning of the trace. | |
43 | * (may overflow) | |
44 | */ | |
45 | uint32_t content_size; /* Size of data in subbuffer */ | |
46 | uint32_t packet_size; /* Subbuffer size (include padding) */ | |
47 | uint32_t cpu_id; /* CPU id associated with stream */ | |
48 | uint8_t header_end; /* End of header */ | |
49 | } ctx; | |
d793d5e1 MD |
50 | }; |
51 | ||
52 | ||
881833e3 MD |
53 | static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan) |
54 | { | |
55 | return trace_clock_read64(); | |
56 | } | |
57 | ||
58 | /* | |
59 | * record_header_size - Calculate the header size and padding necessary. | |
60 | * @config: ring buffer instance configuration | |
61 | * @chan: channel | |
62 | * @offset: offset in the write buffer | |
63 | * @data_size: size of the payload | |
64 | * @pre_header_padding: padding to add before the header (output) | |
65 | * @rflags: reservation flags | |
66 | * @ctx: reservation context | |
67 | * | |
68 | * Returns the event header size (including padding). | |
69 | * | |
881833e3 MD |
70 | * The payload must itself determine its own alignment from the biggest type it |
71 | * contains. | |
72 | */ | |
73 | static __inline__ | |
74 | unsigned char record_header_size(const struct lib_ring_buffer_config *config, | |
75 | struct channel *chan, size_t offset, | |
76 | size_t data_size, size_t *pre_header_padding, | |
77 | unsigned int rflags, | |
78 | struct lib_ring_buffer_ctx *ctx) | |
79 | { | |
9115fbdc | 80 | struct ltt_channel *ltt_chan = channel_get_private(chan); |
881833e3 MD |
81 | size_t orig_offset = offset; |
82 | size_t padding; | |
83 | ||
9115fbdc MD |
84 | switch (ltt_chan->header_type) { |
85 | case 1: /* compact */ | |
86 | padding = lib_ring_buffer_align(offset, ltt_alignof(uint32_t)); | |
87 | offset += padding; | |
88 | if (!(rflags & RING_BUFFER_RFLAG_FULL_TSC)) { | |
89 | offset += sizeof(uint32_t); /* id and timestamp */ | |
90 | } else { | |
91 | /* Minimum space taken by 5-bit id */ | |
92 | offset += sizeof(uint8_t); | |
93 | /* Align extended struct on largest member */ | |
94 | offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t)); | |
95 | offset += sizeof(uint32_t); /* id */ | |
96 | offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t)); | |
97 | offset += sizeof(uint64_t); /* timestamp */ | |
98 | } | |
99 | break; | |
100 | case 2: /* large */ | |
101 | padding = lib_ring_buffer_align(offset, ltt_alignof(uint16_t)); | |
102 | offset += padding; | |
103 | offset += sizeof(uint16_t); | |
104 | if (!(rflags & RING_BUFFER_RFLAG_FULL_TSC)) { | |
105 | offset += lib_ring_buffer_align(offset, ltt_alignof(uint32_t)); | |
106 | offset += sizeof(uint32_t); /* timestamp */ | |
107 | } else { | |
108 | /* Align extended struct on largest member */ | |
109 | offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t)); | |
110 | offset += sizeof(uint32_t); /* id */ | |
111 | offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t)); | |
112 | offset += sizeof(uint64_t); /* timestamp */ | |
113 | ||
881833e3 | 114 | } |
9115fbdc MD |
115 | break; |
116 | default: | |
117 | WARN_ON(1); | |
881833e3 MD |
118 | } |
119 | ||
120 | *pre_header_padding = padding; | |
121 | return offset - orig_offset; | |
122 | } | |
123 | ||
124 | #include "wrapper/ringbuffer/api.h" | |
125 | ||
126 | extern | |
127 | void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config, | |
128 | struct lib_ring_buffer_ctx *ctx, | |
4e1f08f4 | 129 | uint16_t event_id); |
881833e3 MD |
130 | |
131 | /* | |
132 | * ltt_write_event_header | |
133 | * | |
134 | * Writes the event header to the offset (already aligned on 32-bits). | |
135 | * | |
136 | * @config: ring buffer instance configuration | |
137 | * @ctx: reservation context | |
4e1f08f4 | 138 | * @event_id: event ID |
881833e3 MD |
139 | */ |
140 | static __inline__ | |
141 | void ltt_write_event_header(const struct lib_ring_buffer_config *config, | |
142 | struct lib_ring_buffer_ctx *ctx, | |
4e1f08f4 | 143 | uint16_t event_id) |
881833e3 | 144 | { |
9115fbdc | 145 | struct ltt_channel *ltt_chan = channel_get_private(ctx->chan); |
881833e3 MD |
146 | |
147 | if (unlikely(ctx->rflags)) | |
148 | goto slow_path; | |
149 | ||
9115fbdc MD |
150 | switch (ltt_chan->header_type) { |
151 | case 1: /* compact */ | |
152 | { | |
153 | uint32_t id_time = 0; | |
154 | ||
4e1f08f4 | 155 | bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id); |
9115fbdc MD |
156 | bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc); |
157 | lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time)); | |
158 | break; | |
159 | } | |
160 | case 2: /* large */ | |
161 | { | |
9115fbdc MD |
162 | uint32_t timestamp = (uint32_t) ctx->tsc; |
163 | ||
164 | lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id)); | |
165 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t)); | |
166 | lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp)); | |
167 | break; | |
168 | } | |
169 | default: | |
170 | WARN_ON(1); | |
171 | } | |
172 | return; | |
881833e3 MD |
173 | |
174 | slow_path: | |
4e1f08f4 | 175 | ltt_write_event_header_slow(config, ctx, event_id); |
881833e3 MD |
176 | } |
177 | ||
9115fbdc MD |
178 | /* |
179 | * TODO: For now, we only support 65536 event ids per channel. | |
180 | */ | |
881833e3 MD |
181 | void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config, |
182 | struct lib_ring_buffer_ctx *ctx, | |
4e1f08f4 | 183 | uint16_t event_id) |
881833e3 | 184 | { |
9115fbdc MD |
185 | struct ltt_channel *ltt_chan = channel_get_private(ctx->chan); |
186 | ||
187 | switch (ltt_chan->header_type) { | |
188 | case 1: /* compact */ | |
189 | if (!(ctx->rflags & RING_BUFFER_RFLAG_FULL_TSC)) { | |
190 | uint32_t id_time = 0; | |
191 | ||
4e1f08f4 | 192 | bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id); |
9115fbdc MD |
193 | bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc); |
194 | lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time)); | |
195 | } else { | |
196 | uint8_t id = 0; | |
4e1f08f4 | 197 | uint32_t event_id = (uint32_t) event_id; |
9115fbdc MD |
198 | uint64_t timestamp = ctx->tsc; |
199 | ||
200 | bt_bitfield_write(&id, uint8_t, 0, 5, 31); | |
201 | lib_ring_buffer_write(config, ctx, &id, sizeof(id)); | |
202 | /* Align extended struct on largest member */ | |
203 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t)); | |
204 | lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id)); | |
205 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t)); | |
206 | lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp)); | |
207 | } | |
881833e3 | 208 | break; |
9115fbdc MD |
209 | case 2: /* large */ |
210 | { | |
211 | if (!(ctx->rflags & RING_BUFFER_RFLAG_FULL_TSC)) { | |
9115fbdc MD |
212 | uint32_t timestamp = (uint32_t) ctx->tsc; |
213 | ||
214 | lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id)); | |
215 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t)); | |
216 | lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp)); | |
217 | } else { | |
218 | uint16_t event_id = 65535; | |
4e1f08f4 | 219 | uint32_t event_id_ext = (uint32_t) event_id; |
9115fbdc MD |
220 | uint64_t timestamp = ctx->tsc; |
221 | ||
222 | lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id)); | |
223 | /* Align extended struct on largest member */ | |
224 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t)); | |
225 | lib_ring_buffer_write(config, ctx, &event_id_ext, sizeof(event_id_ext)); | |
226 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t)); | |
227 | lib_ring_buffer_write(config, ctx, ×tamp, sizeof(timestamp)); | |
228 | } | |
881833e3 | 229 | break; |
881833e3 | 230 | } |
9115fbdc MD |
231 | default: |
232 | WARN_ON(1); | |
881833e3 MD |
233 | } |
234 | } | |
235 | ||
7514523f MD |
236 | static const struct lib_ring_buffer_config client_config; |
237 | ||
238 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
239 | { | |
240 | return lib_ring_buffer_clock_read(chan); | |
241 | } | |
242 | ||
1e2015dc | 243 | static |
7514523f MD |
244 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, |
245 | struct channel *chan, size_t offset, | |
246 | size_t data_size, | |
247 | size_t *pre_header_padding, | |
248 | unsigned int rflags, | |
249 | struct lib_ring_buffer_ctx *ctx) | |
250 | { | |
251 | return record_header_size(config, chan, offset, data_size, | |
252 | pre_header_padding, rflags, ctx); | |
253 | } | |
254 | ||
255 | /** | |
1c25284c | 256 | * client_packet_header_size - called on buffer-switch to a new sub-buffer |
7514523f MD |
257 | * |
258 | * Return header size without padding after the structure. Don't use packed | |
259 | * structure because gcc generates inefficient code on some architectures | |
260 | * (powerpc, mips..) | |
261 | */ | |
1c25284c | 262 | static size_t client_packet_header_size(void) |
7514523f | 263 | { |
9115fbdc | 264 | return offsetof(struct packet_header, ctx.header_end); |
7514523f MD |
265 | } |
266 | ||
267 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
268 | unsigned int subbuf_idx) | |
269 | { | |
270 | struct channel *chan = buf->backend.chan; | |
1c25284c MD |
271 | struct packet_header *header = |
272 | (struct packet_header *) | |
7514523f MD |
273 | lib_ring_buffer_offset_address(&buf->backend, |
274 | subbuf_idx * chan->backend.subbuf_size); | |
9115fbdc MD |
275 | struct ltt_channel *ltt_chan = channel_get_private(chan); |
276 | struct ltt_session *session = ltt_chan->session; | |
7514523f | 277 | |
d793d5e1 | 278 | header->magic = CTF_MAGIC_NUMBER; |
1ec3f75a | 279 | memcpy(header->uuid, session->uuid.b, sizeof(session->uuid)); |
9115fbdc MD |
280 | header->stream_id = ltt_chan->id; |
281 | header->ctx.timestamp_begin = tsc; | |
282 | header->ctx.timestamp_end = 0; | |
283 | header->ctx.events_discarded = 0; | |
284 | header->ctx.content_size = 0xFFFFFFFF; /* for debugging */ | |
285 | header->ctx.packet_size = 0xFFFFFFFF; | |
286 | header->ctx.cpu_id = buf->backend.cpu; | |
7514523f MD |
287 | } |
288 | ||
289 | /* | |
290 | * offset is assumed to never be 0 here : never deliver a completely empty | |
291 | * subbuffer. data_size is between 1 and subbuf_size. | |
292 | */ | |
293 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
294 | unsigned int subbuf_idx, unsigned long data_size) | |
295 | { | |
296 | struct channel *chan = buf->backend.chan; | |
1c25284c MD |
297 | struct packet_header *header = |
298 | (struct packet_header *) | |
7514523f MD |
299 | lib_ring_buffer_offset_address(&buf->backend, |
300 | subbuf_idx * chan->backend.subbuf_size); | |
301 | unsigned long records_lost = 0; | |
302 | ||
9115fbdc | 303 | header->ctx.timestamp_end = tsc; |
05d32c64 MD |
304 | header->ctx.content_size = data_size * CHAR_BIT; /* in bits */ |
305 | header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */ | |
7514523f MD |
306 | records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf); |
307 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); | |
308 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); | |
9115fbdc | 309 | header->ctx.events_discarded = records_lost; |
7514523f MD |
310 | } |
311 | ||
312 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
313 | int cpu, const char *name) | |
314 | { | |
1c25284c | 315 | return 0; |
7514523f MD |
316 | } |
317 | ||
318 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
319 | { | |
7514523f MD |
320 | } |
321 | ||
322 | static const struct lib_ring_buffer_config client_config = { | |
323 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
324 | .cb.record_header_size = client_record_header_size, | |
1c25284c | 325 | .cb.subbuffer_header_size = client_packet_header_size, |
7514523f MD |
326 | .cb.buffer_begin = client_buffer_begin, |
327 | .cb.buffer_end = client_buffer_end, | |
328 | .cb.buffer_create = client_buffer_create, | |
329 | .cb.buffer_finalize = client_buffer_finalize, | |
330 | ||
331 | .tsc_bits = 32, | |
332 | .alloc = RING_BUFFER_ALLOC_PER_CPU, | |
333 | .sync = RING_BUFFER_SYNC_PER_CPU, | |
3d084699 | 334 | .mode = RING_BUFFER_MODE_TEMPLATE, |
7514523f MD |
335 | .backend = RING_BUFFER_PAGE, |
336 | .output = RING_BUFFER_SPLICE, | |
337 | .oops = RING_BUFFER_OOPS_CONSISTENCY, | |
338 | .ipi = RING_BUFFER_IPI_BARRIER, | |
339 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, | |
340 | }; | |
341 | ||
1e2015dc | 342 | static |
1c25284c | 343 | struct channel *_channel_create(const char *name, |
9115fbdc | 344 | struct ltt_channel *ltt_chan, void *buf_addr, |
1c25284c MD |
345 | size_t subbuf_size, size_t num_subbuf, |
346 | unsigned int switch_timer_interval, | |
347 | unsigned int read_timer_interval) | |
7514523f | 348 | { |
9115fbdc | 349 | return channel_create(&client_config, name, ltt_chan, buf_addr, |
7514523f MD |
350 | subbuf_size, num_subbuf, switch_timer_interval, |
351 | read_timer_interval); | |
7514523f MD |
352 | } |
353 | ||
1e2015dc | 354 | static |
7514523f MD |
355 | void ltt_channel_destroy(struct channel *chan) |
356 | { | |
7514523f | 357 | channel_destroy(chan); |
7514523f MD |
358 | } |
359 | ||
ad1c05e1 MD |
360 | static |
361 | struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan) | |
362 | { | |
363 | struct lib_ring_buffer *buf; | |
364 | int cpu; | |
365 | ||
1c25284c MD |
366 | for_each_channel_cpu(cpu, chan) { |
367 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
ad1c05e1 MD |
368 | if (!lib_ring_buffer_open_read(buf)) |
369 | return buf; | |
370 | } | |
371 | return NULL; | |
372 | } | |
373 | ||
374 | static | |
1c25284c | 375 | void ltt_buffer_read_close(struct lib_ring_buffer *buf) |
ad1c05e1 MD |
376 | { |
377 | lib_ring_buffer_release_read(buf); | |
1c25284c MD |
378 | |
379 | } | |
380 | ||
c099397a | 381 | static |
4e1f08f4 MD |
382 | int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx, |
383 | uint16_t event_id) | |
1c25284c MD |
384 | { |
385 | int ret, cpu; | |
386 | ||
387 | cpu = lib_ring_buffer_get_cpu(&client_config); | |
388 | if (cpu < 0) | |
389 | return -EPERM; | |
390 | ctx->cpu = cpu; | |
391 | ||
392 | ret = lib_ring_buffer_reserve(&client_config, ctx); | |
393 | if (ret) | |
394 | goto put; | |
4e1f08f4 MD |
395 | ltt_write_event_header(&client_config, ctx, event_id); |
396 | return 0; | |
1c25284c MD |
397 | put: |
398 | lib_ring_buffer_put_cpu(&client_config); | |
399 | return ret; | |
ad1c05e1 MD |
400 | } |
401 | ||
c099397a | 402 | static |
1c25284c MD |
403 | void ltt_event_commit(struct lib_ring_buffer_ctx *ctx) |
404 | { | |
405 | lib_ring_buffer_commit(&client_config, ctx); | |
406 | lib_ring_buffer_put_cpu(&client_config); | |
407 | } | |
408 | ||
c099397a | 409 | static |
e763dbf5 MD |
410 | void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, |
411 | size_t len) | |
412 | { | |
413 | lib_ring_buffer_write(&client_config, ctx, src, len); | |
414 | } | |
1c25284c | 415 | |
c099397a MD |
416 | static |
417 | wait_queue_head_t *ltt_get_reader_wait_queue(struct ltt_channel *chan) | |
418 | { | |
419 | return &chan->chan->read_wait; | |
420 | } | |
421 | ||
7514523f | 422 | static struct ltt_transport ltt_relay_transport = { |
3d084699 | 423 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, |
7514523f MD |
424 | .owner = THIS_MODULE, |
425 | .ops = { | |
1c25284c MD |
426 | .channel_create = _channel_create, |
427 | .channel_destroy = ltt_channel_destroy, | |
ad1c05e1 MD |
428 | .buffer_read_open = ltt_buffer_read_open, |
429 | .buffer_read_close = ltt_buffer_read_close, | |
1c25284c MD |
430 | .event_reserve = ltt_event_reserve, |
431 | .event_commit = ltt_event_commit, | |
e763dbf5 | 432 | .event_write = ltt_event_write, |
1ec3f75a | 433 | .packet_avail_size = NULL, /* Would be racy anyway */ |
c099397a | 434 | .get_reader_wait_queue = ltt_get_reader_wait_queue, |
7514523f MD |
435 | }, |
436 | }; | |
437 | ||
3d084699 | 438 | static int __init ltt_ring_buffer_client_init(void) |
7514523f | 439 | { |
a509e133 MD |
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 | */ | |
6d2a620c | 444 | wrapper_vmalloc_sync_all(); |
7514523f MD |
445 | printk(KERN_INFO "LTT : ltt ring buffer client init\n"); |
446 | ltt_transport_register(<t_relay_transport); | |
447 | return 0; | |
448 | } | |
449 | ||
1c25284c MD |
450 | module_init(ltt_ring_buffer_client_init); |
451 | ||
3d084699 | 452 | static void __exit ltt_ring_buffer_client_exit(void) |
7514523f MD |
453 | { |
454 | printk(KERN_INFO "LTT : ltt ring buffer client exit\n"); | |
455 | ltt_transport_unregister(<t_relay_transport); | |
456 | } | |
457 | ||
1c25284c MD |
458 | module_exit(ltt_ring_buffer_client_exit); |
459 | ||
7514523f MD |
460 | MODULE_LICENSE("GPL and additional rights"); |
461 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
3d084699 MD |
462 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING |
463 | " client"); |