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> |
b13f3ebe | 13 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ |
f3bc08c5 | 14 | #include "wrapper/trace-clock.h" |
c0e31d2e | 15 | #include "ltt-events.h" |
7514523f MD |
16 | #include "ltt-tracer.h" |
17 | ||
d793d5e1 MD |
18 | /* |
19 | * Keep the natural field alignment for _each field_ within this structure if | |
20 | * you ever add/remove a field from this header. Packed attribute is not used | |
21 | * because gcc generates poor code on at least powerpc and mips. Don't ever | |
22 | * let gcc add padding between the structure elements. | |
23 | */ | |
24 | struct packet_header { | |
25 | uint32_t magic; /* | |
26 | * Trace magic number. | |
27 | * contains endianness information. | |
28 | */ | |
1ec3f75a | 29 | uint8_t uuid[16]; |
d793d5e1 MD |
30 | uint32_t stream_id; |
31 | uint64_t timestamp_begin; /* Cycle count at subbuffer start */ | |
32 | uint64_t timestamp_end; /* Cycle count at subbuffer end */ | |
33 | uint32_t content_size; /* Size of data in subbuffer */ | |
34 | uint32_t packet_size; /* Subbuffer size (include padding) */ | |
35 | uint32_t events_lost; /* | |
36 | * Events lost in this subbuffer since | |
37 | * the beginning of the trace. | |
38 | * (may overflow) | |
39 | */ | |
40 | #if 0 | |
41 | uint64_t start_time_sec; /* NTP-corrected start time */ | |
42 | uint64_t start_time_usec; | |
43 | uint64_t start_freq; /* | |
44 | * Frequency at trace start, | |
45 | * used all along the trace. | |
46 | */ | |
47 | uint32_t freq_scale; /* Frequency scaling (divisor) */ | |
48 | #endif //0 | |
49 | uint8_t header_end[0]; /* End of header */ | |
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 | * | |
70 | * Important note : | |
71 | * The event header must be 32-bits. The total offset calculated here : | |
72 | * | |
73 | * Alignment of header struct on 32 bits (min arch size, header size) | |
74 | * + sizeof(header struct) (32-bits) | |
75 | * + (opt) u16 (ext. event id) | |
76 | * + (opt) u16 (event_size) | |
77 | * (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size) | |
78 | * + (opt) u32 (ext. event size) | |
79 | * + (opt) u64 full TSC (aligned on min(64-bits, arch size)) | |
80 | * | |
81 | * The payload must itself determine its own alignment from the biggest type it | |
82 | * contains. | |
83 | */ | |
84 | static __inline__ | |
85 | unsigned char record_header_size(const struct lib_ring_buffer_config *config, | |
86 | struct channel *chan, size_t offset, | |
87 | size_t data_size, size_t *pre_header_padding, | |
88 | unsigned int rflags, | |
89 | struct lib_ring_buffer_ctx *ctx) | |
90 | { | |
91 | size_t orig_offset = offset; | |
92 | size_t padding; | |
93 | ||
94 | BUILD_BUG_ON(sizeof(struct event_header) != sizeof(u32)); | |
95 | ||
96 | padding = lib_ring_buffer_align(offset, | |
97 | sizeof(struct event_header)); | |
98 | offset += padding; | |
99 | offset += sizeof(struct event_header); | |
100 | ||
101 | if (unlikely(rflags)) { | |
102 | switch (rflags) { | |
103 | case LTT_RFLAG_ID_SIZE_TSC: | |
104 | offset += sizeof(u16) + sizeof(u16); | |
105 | if (data_size >= LTT_MAX_SMALL_SIZE) | |
106 | offset += sizeof(u32); | |
107 | offset += lib_ring_buffer_align(offset, sizeof(u64)); | |
108 | offset += sizeof(u64); | |
109 | break; | |
110 | case LTT_RFLAG_ID_SIZE: | |
111 | offset += sizeof(u16) + sizeof(u16); | |
112 | if (data_size >= LTT_MAX_SMALL_SIZE) | |
113 | offset += sizeof(u32); | |
114 | break; | |
115 | case LTT_RFLAG_ID: | |
116 | offset += sizeof(u16); | |
117 | break; | |
118 | } | |
119 | } | |
120 | ||
121 | *pre_header_padding = padding; | |
122 | return offset - orig_offset; | |
123 | } | |
124 | ||
125 | #include "wrapper/ringbuffer/api.h" | |
126 | ||
127 | extern | |
128 | void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config, | |
129 | struct lib_ring_buffer_ctx *ctx, | |
130 | u16 eID, u32 event_size); | |
131 | ||
132 | /* | |
133 | * ltt_write_event_header | |
134 | * | |
135 | * Writes the event header to the offset (already aligned on 32-bits). | |
136 | * | |
137 | * @config: ring buffer instance configuration | |
138 | * @ctx: reservation context | |
139 | * @eID : event ID | |
140 | * @event_size : size of the event, excluding the event header. | |
141 | */ | |
142 | static __inline__ | |
143 | void ltt_write_event_header(const struct lib_ring_buffer_config *config, | |
144 | struct lib_ring_buffer_ctx *ctx, | |
145 | u16 eID, u32 event_size) | |
146 | { | |
147 | struct event_header header; | |
148 | ||
149 | if (unlikely(ctx->rflags)) | |
150 | goto slow_path; | |
151 | ||
152 | header.id_time = eID << LTT_TSC_BITS; | |
153 | header.id_time |= (u32)ctx->tsc & LTT_TSC_MASK; | |
154 | lib_ring_buffer_write(config, ctx, &header, sizeof(header)); | |
155 | ||
156 | slow_path: | |
157 | ltt_write_event_header_slow(config, ctx, eID, event_size); | |
158 | } | |
159 | ||
881833e3 MD |
160 | void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config, |
161 | struct lib_ring_buffer_ctx *ctx, | |
162 | u16 eID, u32 event_size) | |
163 | { | |
164 | struct event_header header; | |
165 | u16 small_size; | |
166 | ||
167 | switch (ctx->rflags) { | |
168 | case LTT_RFLAG_ID_SIZE_TSC: | |
169 | header.id_time = 29 << LTT_TSC_BITS; | |
170 | break; | |
171 | case LTT_RFLAG_ID_SIZE: | |
172 | header.id_time = 30 << LTT_TSC_BITS; | |
173 | break; | |
174 | case LTT_RFLAG_ID: | |
175 | header.id_time = 31 << LTT_TSC_BITS; | |
176 | break; | |
177 | default: | |
178 | WARN_ON_ONCE(1); | |
179 | header.id_time = 0; | |
180 | } | |
181 | ||
182 | header.id_time |= (u32)ctx->tsc & LTT_TSC_MASK; | |
183 | lib_ring_buffer_write(config, ctx, &header, sizeof(header)); | |
184 | ||
185 | switch (ctx->rflags) { | |
186 | case LTT_RFLAG_ID_SIZE_TSC: | |
187 | small_size = (u16)min_t(u32, event_size, LTT_MAX_SMALL_SIZE); | |
188 | lib_ring_buffer_write(config, ctx, &eID, sizeof(u16)); | |
189 | lib_ring_buffer_write(config, ctx, &small_size, sizeof(u16)); | |
190 | if (small_size == LTT_MAX_SMALL_SIZE) | |
191 | lib_ring_buffer_write(config, ctx, &event_size, | |
192 | sizeof(u32)); | |
193 | lib_ring_buffer_align_ctx(ctx, sizeof(u64)); | |
194 | lib_ring_buffer_write(config, ctx, &ctx->tsc, sizeof(u64)); | |
195 | break; | |
196 | case LTT_RFLAG_ID_SIZE: | |
197 | small_size = (u16)min_t(u32, event_size, LTT_MAX_SMALL_SIZE); | |
198 | lib_ring_buffer_write(config, ctx, &eID, sizeof(u16)); | |
199 | lib_ring_buffer_write(config, ctx, &small_size, sizeof(u16)); | |
200 | if (small_size == LTT_MAX_SMALL_SIZE) | |
201 | lib_ring_buffer_write(config, ctx, &event_size, | |
202 | sizeof(u32)); | |
203 | break; | |
204 | case LTT_RFLAG_ID: | |
205 | lib_ring_buffer_write(config, ctx, &eID, sizeof(u16)); | |
206 | break; | |
207 | } | |
208 | } | |
209 | ||
7514523f MD |
210 | static const struct lib_ring_buffer_config client_config; |
211 | ||
212 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
213 | { | |
214 | return lib_ring_buffer_clock_read(chan); | |
215 | } | |
216 | ||
1e2015dc | 217 | static |
7514523f MD |
218 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, |
219 | struct channel *chan, size_t offset, | |
220 | size_t data_size, | |
221 | size_t *pre_header_padding, | |
222 | unsigned int rflags, | |
223 | struct lib_ring_buffer_ctx *ctx) | |
224 | { | |
225 | return record_header_size(config, chan, offset, data_size, | |
226 | pre_header_padding, rflags, ctx); | |
227 | } | |
228 | ||
229 | /** | |
1c25284c | 230 | * client_packet_header_size - called on buffer-switch to a new sub-buffer |
7514523f MD |
231 | * |
232 | * Return header size without padding after the structure. Don't use packed | |
233 | * structure because gcc generates inefficient code on some architectures | |
234 | * (powerpc, mips..) | |
235 | */ | |
1c25284c | 236 | static size_t client_packet_header_size(void) |
7514523f | 237 | { |
1c25284c | 238 | return offsetof(struct packet_header, header_end); |
7514523f MD |
239 | } |
240 | ||
241 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
242 | unsigned int subbuf_idx) | |
243 | { | |
244 | struct channel *chan = buf->backend.chan; | |
1c25284c MD |
245 | struct packet_header *header = |
246 | (struct packet_header *) | |
7514523f MD |
247 | lib_ring_buffer_offset_address(&buf->backend, |
248 | subbuf_idx * chan->backend.subbuf_size); | |
d793d5e1 | 249 | struct ltt_session *session = channel_get_private(chan); |
7514523f | 250 | |
d793d5e1 | 251 | header->magic = CTF_MAGIC_NUMBER; |
1ec3f75a | 252 | memcpy(header->uuid, session->uuid.b, sizeof(session->uuid)); |
1c25284c | 253 | header->timestamp_begin = tsc; |
d793d5e1 | 254 | header->timestamp_end = 0; |
1c25284c | 255 | header->content_size = 0xFFFFFFFF; /* for debugging */ |
d793d5e1 MD |
256 | header->packet_size = 0xFFFFFFFF; |
257 | header->events_lost = 0; | |
258 | #if 0 | |
259 | header->start_time_sec = ltt_chan->session->start_time.tv_sec; | |
260 | header->start_time_usec = ltt_chan->session->start_time.tv_usec; | |
261 | header->start_freq = ltt_chan->session->start_freq; | |
262 | header->freq_scale = ltt_chan->session->freq_scale; | |
263 | #endif //0 | |
7514523f MD |
264 | } |
265 | ||
266 | /* | |
267 | * offset is assumed to never be 0 here : never deliver a completely empty | |
268 | * subbuffer. data_size is between 1 and subbuf_size. | |
269 | */ | |
270 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
271 | unsigned int subbuf_idx, unsigned long data_size) | |
272 | { | |
273 | struct channel *chan = buf->backend.chan; | |
1c25284c MD |
274 | struct packet_header *header = |
275 | (struct packet_header *) | |
7514523f MD |
276 | lib_ring_buffer_offset_address(&buf->backend, |
277 | subbuf_idx * chan->backend.subbuf_size); | |
278 | unsigned long records_lost = 0; | |
279 | ||
d793d5e1 | 280 | header->timestamp_end = tsc; |
1c25284c MD |
281 | header->content_size = data_size; |
282 | header->packet_size = PAGE_ALIGN(data_size); | |
7514523f MD |
283 | records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf); |
284 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); | |
285 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); | |
286 | header->events_lost = records_lost; | |
7514523f MD |
287 | } |
288 | ||
289 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
290 | int cpu, const char *name) | |
291 | { | |
1c25284c | 292 | return 0; |
7514523f MD |
293 | } |
294 | ||
295 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
296 | { | |
7514523f MD |
297 | } |
298 | ||
299 | static const struct lib_ring_buffer_config client_config = { | |
300 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
301 | .cb.record_header_size = client_record_header_size, | |
1c25284c | 302 | .cb.subbuffer_header_size = client_packet_header_size, |
7514523f MD |
303 | .cb.buffer_begin = client_buffer_begin, |
304 | .cb.buffer_end = client_buffer_end, | |
305 | .cb.buffer_create = client_buffer_create, | |
306 | .cb.buffer_finalize = client_buffer_finalize, | |
307 | ||
308 | .tsc_bits = 32, | |
309 | .alloc = RING_BUFFER_ALLOC_PER_CPU, | |
310 | .sync = RING_BUFFER_SYNC_PER_CPU, | |
3d084699 | 311 | .mode = RING_BUFFER_MODE_TEMPLATE, |
7514523f MD |
312 | .backend = RING_BUFFER_PAGE, |
313 | .output = RING_BUFFER_SPLICE, | |
314 | .oops = RING_BUFFER_OOPS_CONSISTENCY, | |
315 | .ipi = RING_BUFFER_IPI_BARRIER, | |
316 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, | |
317 | }; | |
318 | ||
1e2015dc | 319 | static |
1c25284c MD |
320 | struct channel *_channel_create(const char *name, |
321 | struct ltt_session *session, void *buf_addr, | |
322 | size_t subbuf_size, size_t num_subbuf, | |
323 | unsigned int switch_timer_interval, | |
324 | unsigned int read_timer_interval) | |
7514523f | 325 | { |
1c25284c | 326 | return channel_create(&client_config, name, session, buf_addr, |
7514523f MD |
327 | subbuf_size, num_subbuf, switch_timer_interval, |
328 | read_timer_interval); | |
7514523f MD |
329 | } |
330 | ||
1e2015dc | 331 | static |
7514523f MD |
332 | void ltt_channel_destroy(struct channel *chan) |
333 | { | |
7514523f | 334 | channel_destroy(chan); |
7514523f MD |
335 | } |
336 | ||
ad1c05e1 MD |
337 | static |
338 | struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan) | |
339 | { | |
340 | struct lib_ring_buffer *buf; | |
341 | int cpu; | |
342 | ||
1c25284c MD |
343 | for_each_channel_cpu(cpu, chan) { |
344 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
ad1c05e1 MD |
345 | if (!lib_ring_buffer_open_read(buf)) |
346 | return buf; | |
347 | } | |
348 | return NULL; | |
349 | } | |
350 | ||
351 | static | |
1c25284c | 352 | void ltt_buffer_read_close(struct lib_ring_buffer *buf) |
ad1c05e1 MD |
353 | { |
354 | lib_ring_buffer_release_read(buf); | |
1c25284c MD |
355 | |
356 | } | |
357 | ||
c099397a | 358 | static |
1c25284c MD |
359 | int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx) |
360 | { | |
361 | int ret, cpu; | |
362 | ||
363 | cpu = lib_ring_buffer_get_cpu(&client_config); | |
364 | if (cpu < 0) | |
365 | return -EPERM; | |
366 | ctx->cpu = cpu; | |
367 | ||
368 | ret = lib_ring_buffer_reserve(&client_config, ctx); | |
369 | if (ret) | |
370 | goto put; | |
371 | return ret; | |
372 | ||
373 | put: | |
374 | lib_ring_buffer_put_cpu(&client_config); | |
375 | return ret; | |
ad1c05e1 MD |
376 | } |
377 | ||
c099397a | 378 | static |
1c25284c MD |
379 | void ltt_event_commit(struct lib_ring_buffer_ctx *ctx) |
380 | { | |
381 | lib_ring_buffer_commit(&client_config, ctx); | |
382 | lib_ring_buffer_put_cpu(&client_config); | |
383 | } | |
384 | ||
c099397a | 385 | static |
e763dbf5 MD |
386 | void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, |
387 | size_t len) | |
388 | { | |
389 | lib_ring_buffer_write(&client_config, ctx, src, len); | |
390 | } | |
1c25284c | 391 | |
c099397a MD |
392 | static |
393 | wait_queue_head_t *ltt_get_reader_wait_queue(struct ltt_channel *chan) | |
394 | { | |
395 | return &chan->chan->read_wait; | |
396 | } | |
397 | ||
7514523f | 398 | static struct ltt_transport ltt_relay_transport = { |
3d084699 | 399 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, |
7514523f MD |
400 | .owner = THIS_MODULE, |
401 | .ops = { | |
1c25284c MD |
402 | .channel_create = _channel_create, |
403 | .channel_destroy = ltt_channel_destroy, | |
ad1c05e1 MD |
404 | .buffer_read_open = ltt_buffer_read_open, |
405 | .buffer_read_close = ltt_buffer_read_close, | |
1c25284c MD |
406 | .event_reserve = ltt_event_reserve, |
407 | .event_commit = ltt_event_commit, | |
e763dbf5 | 408 | .event_write = ltt_event_write, |
1ec3f75a | 409 | .packet_avail_size = NULL, /* Would be racy anyway */ |
c099397a | 410 | .get_reader_wait_queue = ltt_get_reader_wait_queue, |
7514523f MD |
411 | }, |
412 | }; | |
413 | ||
3d084699 | 414 | static int __init ltt_ring_buffer_client_init(void) |
7514523f | 415 | { |
a509e133 MD |
416 | /* |
417 | * This vmalloc sync all also takes care of the lib ring buffer | |
418 | * vmalloc'd module pages when it is built as a module into LTTng. | |
419 | */ | |
6d2a620c | 420 | wrapper_vmalloc_sync_all(); |
7514523f MD |
421 | printk(KERN_INFO "LTT : ltt ring buffer client init\n"); |
422 | ltt_transport_register(<t_relay_transport); | |
423 | return 0; | |
424 | } | |
425 | ||
1c25284c MD |
426 | module_init(ltt_ring_buffer_client_init); |
427 | ||
3d084699 | 428 | static void __exit ltt_ring_buffer_client_exit(void) |
7514523f MD |
429 | { |
430 | printk(KERN_INFO "LTT : ltt ring buffer client exit\n"); | |
431 | ltt_transport_unregister(<t_relay_transport); | |
432 | } | |
433 | ||
1c25284c MD |
434 | module_exit(ltt_ring_buffer_client_exit); |
435 | ||
7514523f MD |
436 | MODULE_LICENSE("GPL and additional rights"); |
437 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
3d084699 MD |
438 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING |
439 | " client"); |