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881833e3 | 1 | /* |
a90917c3 | 2 | * lttng-ring-buffer-client.h |
881833e3 | 3 | * |
881833e3 MD |
4 | * LTTng lib ring buffer client template. |
5 | * | |
886d51a3 MD |
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 | |
881833e3 MD |
21 | */ |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/types.h> | |
25 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ | |
a90917c3 MD |
26 | #include "lttng-events.h" |
27 | #include "lttng-tracer.h" | |
881833e3 | 28 | |
881833e3 MD |
29 | struct metadata_packet_header { |
30 | uint32_t magic; /* 0x75D11D57 */ | |
1ec3f75a | 31 | uint8_t uuid[16]; /* Unique Universal Identifier */ |
881833e3 MD |
32 | uint32_t checksum; /* 0 if unused */ |
33 | uint32_t content_size; /* in bits */ | |
34 | uint32_t packet_size; /* in bits */ | |
35 | uint8_t compression_scheme; /* 0 if unused */ | |
36 | uint8_t encryption_scheme; /* 0 if unused */ | |
37 | uint8_t checksum_scheme; /* 0 if unused */ | |
4173df96 MD |
38 | uint8_t major; /* CTF spec major version number */ |
39 | uint8_t minor; /* CTF spec minor version number */ | |
881833e3 MD |
40 | uint8_t header_end[0]; |
41 | }; | |
42 | ||
43 | struct metadata_record_header { | |
44 | uint8_t header_end[0]; /* End of header */ | |
45 | }; | |
46 | ||
47 | static const struct lib_ring_buffer_config client_config; | |
48 | ||
49 | static inline | |
50 | u64 lib_ring_buffer_clock_read(struct channel *chan) | |
51 | { | |
52 | return 0; | |
53 | } | |
54 | ||
55 | static inline | |
56 | unsigned char record_header_size(const struct lib_ring_buffer_config *config, | |
57 | struct channel *chan, size_t offset, | |
64c796d8 | 58 | size_t *pre_header_padding, |
881833e3 MD |
59 | struct lib_ring_buffer_ctx *ctx) |
60 | { | |
61 | return 0; | |
62 | } | |
63 | ||
64 | #include "wrapper/ringbuffer/api.h" | |
65 | ||
66 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
67 | { | |
68 | return 0; | |
69 | } | |
70 | ||
71 | static | |
72 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, | |
73 | struct channel *chan, size_t offset, | |
881833e3 | 74 | size_t *pre_header_padding, |
881833e3 MD |
75 | struct lib_ring_buffer_ctx *ctx) |
76 | { | |
77 | return 0; | |
78 | } | |
79 | ||
80 | /** | |
81 | * client_packet_header_size - called on buffer-switch to a new sub-buffer | |
82 | * | |
83 | * Return header size without padding after the structure. Don't use packed | |
84 | * structure because gcc generates inefficient code on some architectures | |
85 | * (powerpc, mips..) | |
86 | */ | |
87 | static size_t client_packet_header_size(void) | |
88 | { | |
89 | return offsetof(struct metadata_packet_header, header_end); | |
90 | } | |
91 | ||
92 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
93 | unsigned int subbuf_idx) | |
94 | { | |
95 | struct channel *chan = buf->backend.chan; | |
96 | struct metadata_packet_header *header = | |
97 | (struct metadata_packet_header *) | |
98 | lib_ring_buffer_offset_address(&buf->backend, | |
99 | subbuf_idx * chan->backend.subbuf_size); | |
a90917c3 MD |
100 | struct lttng_channel *lttng_chan = channel_get_private(chan); |
101 | struct lttng_session *session = lttng_chan->session; | |
881833e3 MD |
102 | |
103 | header->magic = TSDL_MAGIC_NUMBER; | |
1ec3f75a | 104 | memcpy(header->uuid, session->uuid.b, sizeof(session->uuid)); |
881833e3 MD |
105 | header->checksum = 0; /* 0 if unused */ |
106 | header->content_size = 0xFFFFFFFF; /* in bits, for debugging */ | |
107 | header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */ | |
108 | header->compression_scheme = 0; /* 0 if unused */ | |
109 | header->encryption_scheme = 0; /* 0 if unused */ | |
110 | header->checksum_scheme = 0; /* 0 if unused */ | |
4173df96 MD |
111 | header->major = CTF_SPEC_MAJOR; |
112 | header->minor = CTF_SPEC_MINOR; | |
881833e3 MD |
113 | } |
114 | ||
115 | /* | |
116 | * offset is assumed to never be 0 here : never deliver a completely empty | |
117 | * subbuffer. data_size is between 1 and subbuf_size. | |
118 | */ | |
119 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
120 | unsigned int subbuf_idx, unsigned long data_size) | |
121 | { | |
122 | struct channel *chan = buf->backend.chan; | |
d793d5e1 | 123 | struct metadata_packet_header *header = |
1ec3f75a | 124 | (struct metadata_packet_header *) |
881833e3 MD |
125 | lib_ring_buffer_offset_address(&buf->backend, |
126 | subbuf_idx * chan->backend.subbuf_size); | |
127 | unsigned long records_lost = 0; | |
128 | ||
129 | header->content_size = data_size * CHAR_BIT; /* in bits */ | |
130 | header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */ | |
71c1d843 MD |
131 | /* |
132 | * We do not care about the records lost count, because the metadata | |
133 | * channel waits and retry. | |
134 | */ | |
135 | (void) lib_ring_buffer_get_records_lost_full(&client_config, buf); | |
881833e3 MD |
136 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); |
137 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); | |
138 | WARN_ON_ONCE(records_lost != 0); | |
139 | } | |
140 | ||
141 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
142 | int cpu, const char *name) | |
143 | { | |
144 | return 0; | |
145 | } | |
146 | ||
147 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
148 | { | |
149 | } | |
150 | ||
151 | static const struct lib_ring_buffer_config client_config = { | |
152 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
153 | .cb.record_header_size = client_record_header_size, | |
154 | .cb.subbuffer_header_size = client_packet_header_size, | |
155 | .cb.buffer_begin = client_buffer_begin, | |
156 | .cb.buffer_end = client_buffer_end, | |
157 | .cb.buffer_create = client_buffer_create, | |
158 | .cb.buffer_finalize = client_buffer_finalize, | |
159 | ||
160 | .tsc_bits = 0, | |
161 | .alloc = RING_BUFFER_ALLOC_GLOBAL, | |
162 | .sync = RING_BUFFER_SYNC_GLOBAL, | |
163 | .mode = RING_BUFFER_MODE_TEMPLATE, | |
164 | .backend = RING_BUFFER_PAGE, | |
2db1399a | 165 | .output = RING_BUFFER_OUTPUT_TEMPLATE, |
881833e3 MD |
166 | .oops = RING_BUFFER_OOPS_CONSISTENCY, |
167 | .ipi = RING_BUFFER_IPI_BARRIER, | |
168 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, | |
169 | }; | |
170 | ||
171 | static | |
172 | struct channel *_channel_create(const char *name, | |
a90917c3 | 173 | struct lttng_channel *lttng_chan, void *buf_addr, |
881833e3 MD |
174 | size_t subbuf_size, size_t num_subbuf, |
175 | unsigned int switch_timer_interval, | |
176 | unsigned int read_timer_interval) | |
177 | { | |
a90917c3 | 178 | return channel_create(&client_config, name, lttng_chan, buf_addr, |
881833e3 MD |
179 | subbuf_size, num_subbuf, switch_timer_interval, |
180 | read_timer_interval); | |
181 | } | |
182 | ||
183 | static | |
a90917c3 | 184 | void lttng_channel_destroy(struct channel *chan) |
881833e3 MD |
185 | { |
186 | channel_destroy(chan); | |
187 | } | |
188 | ||
189 | static | |
a90917c3 | 190 | struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan) |
881833e3 MD |
191 | { |
192 | struct lib_ring_buffer *buf; | |
881833e3 | 193 | |
cd4bd11f MD |
194 | buf = channel_get_ring_buffer(&client_config, chan, 0); |
195 | if (!lib_ring_buffer_open_read(buf)) | |
196 | return buf; | |
881833e3 MD |
197 | return NULL; |
198 | } | |
199 | ||
f71ecafa | 200 | static |
a90917c3 | 201 | int lttng_buffer_has_read_closed_stream(struct channel *chan) |
f71ecafa MD |
202 | { |
203 | struct lib_ring_buffer *buf; | |
204 | int cpu; | |
205 | ||
206 | for_each_channel_cpu(cpu, chan) { | |
207 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
208 | if (!atomic_long_read(&buf->active_readers)) | |
209 | return 1; | |
210 | } | |
211 | return 0; | |
212 | } | |
213 | ||
881833e3 | 214 | static |
a90917c3 | 215 | void lttng_buffer_read_close(struct lib_ring_buffer *buf) |
881833e3 MD |
216 | { |
217 | lib_ring_buffer_release_read(buf); | |
881833e3 MD |
218 | } |
219 | ||
c099397a | 220 | static |
a90917c3 | 221 | int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id) |
881833e3 MD |
222 | { |
223 | return lib_ring_buffer_reserve(&client_config, ctx); | |
224 | } | |
225 | ||
c099397a | 226 | static |
a90917c3 | 227 | void lttng_event_commit(struct lib_ring_buffer_ctx *ctx) |
881833e3 MD |
228 | { |
229 | lib_ring_buffer_commit(&client_config, ctx); | |
230 | } | |
231 | ||
c099397a | 232 | static |
a90917c3 | 233 | void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, |
881833e3 MD |
234 | size_t len) |
235 | { | |
236 | lib_ring_buffer_write(&client_config, ctx, src, len); | |
237 | } | |
238 | ||
4ea00e4f | 239 | static |
a90917c3 | 240 | void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx, |
4ea00e4f JD |
241 | const void __user *src, size_t len) |
242 | { | |
7b8ea3a5 | 243 | lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len); |
4ea00e4f JD |
244 | } |
245 | ||
58aa5d24 | 246 | static |
a90917c3 | 247 | void lttng_event_memset(struct lib_ring_buffer_ctx *ctx, |
58aa5d24 MD |
248 | int c, size_t len) |
249 | { | |
250 | lib_ring_buffer_memset(&client_config, ctx, c, len); | |
251 | } | |
252 | ||
1ec3f75a | 253 | static |
a90917c3 | 254 | size_t lttng_packet_avail_size(struct channel *chan) |
1ec3f75a MD |
255 | |
256 | { | |
257 | unsigned long o_begin; | |
258 | struct lib_ring_buffer *buf; | |
259 | ||
260 | buf = chan->backend.buf; /* Only for global buffer ! */ | |
261 | o_begin = v_read(&client_config, &buf->offset); | |
262 | if (subbuf_offset(o_begin, chan) != 0) { | |
263 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan); | |
264 | } else { | |
265 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan) | |
266 | - sizeof(struct metadata_packet_header); | |
267 | } | |
268 | } | |
269 | ||
c099397a | 270 | static |
a90917c3 | 271 | wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu) |
c099397a | 272 | { |
71c1d843 MD |
273 | struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config, |
274 | chan, cpu); | |
275 | return &buf->write_wait; | |
24cedcfe MD |
276 | } |
277 | ||
278 | static | |
a90917c3 | 279 | wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan) |
24cedcfe MD |
280 | { |
281 | return &chan->hp_wait; | |
282 | } | |
283 | ||
284 | static | |
a90917c3 | 285 | int lttng_is_finalized(struct channel *chan) |
24cedcfe MD |
286 | { |
287 | return lib_ring_buffer_channel_is_finalized(chan); | |
c099397a MD |
288 | } |
289 | ||
254ec7bc | 290 | static |
a90917c3 | 291 | int lttng_is_disabled(struct channel *chan) |
254ec7bc MD |
292 | { |
293 | return lib_ring_buffer_channel_is_disabled(chan); | |
294 | } | |
295 | ||
a90917c3 | 296 | static struct lttng_transport lttng_relay_transport = { |
881833e3 MD |
297 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, |
298 | .owner = THIS_MODULE, | |
299 | .ops = { | |
300 | .channel_create = _channel_create, | |
a90917c3 MD |
301 | .channel_destroy = lttng_channel_destroy, |
302 | .buffer_read_open = lttng_buffer_read_open, | |
f71ecafa | 303 | .buffer_has_read_closed_stream = |
a90917c3 MD |
304 | lttng_buffer_has_read_closed_stream, |
305 | .buffer_read_close = lttng_buffer_read_close, | |
306 | .event_reserve = lttng_event_reserve, | |
307 | .event_commit = lttng_event_commit, | |
308 | .event_write_from_user = lttng_event_write_from_user, | |
309 | .event_memset = lttng_event_memset, | |
310 | .event_write = lttng_event_write, | |
311 | .packet_avail_size = lttng_packet_avail_size, | |
312 | .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue, | |
313 | .get_hp_wait_queue = lttng_get_hp_wait_queue, | |
314 | .is_finalized = lttng_is_finalized, | |
315 | .is_disabled = lttng_is_disabled, | |
881833e3 MD |
316 | }, |
317 | }; | |
318 | ||
a90917c3 | 319 | static int __init lttng_ring_buffer_client_init(void) |
881833e3 MD |
320 | { |
321 | /* | |
322 | * This vmalloc sync all also takes care of the lib ring buffer | |
323 | * vmalloc'd module pages when it is built as a module into LTTng. | |
324 | */ | |
325 | wrapper_vmalloc_sync_all(); | |
a90917c3 | 326 | lttng_transport_register(<tng_relay_transport); |
881833e3 MD |
327 | return 0; |
328 | } | |
329 | ||
a90917c3 | 330 | module_init(lttng_ring_buffer_client_init); |
881833e3 | 331 | |
a90917c3 | 332 | static void __exit lttng_ring_buffer_client_exit(void) |
881833e3 | 333 | { |
a90917c3 | 334 | lttng_transport_unregister(<tng_relay_transport); |
881833e3 MD |
335 | } |
336 | ||
a90917c3 | 337 | module_exit(lttng_ring_buffer_client_exit); |
881833e3 MD |
338 | |
339 | MODULE_LICENSE("GPL and additional rights"); | |
340 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
341 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING | |
342 | " client"); |