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881833e3 | 1 | /* |
a90917c3 | 2 | * lttng-ring-buffer-client.h |
881833e3 MD |
3 | * |
4 | * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * LTTng lib ring buffer client template. | |
7 | * | |
8 | * Dual LGPL v2.1/GPL v2 license. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/types.h> | |
13 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ | |
a90917c3 MD |
14 | #include "lttng-events.h" |
15 | #include "lttng-tracer.h" | |
881833e3 | 16 | |
881833e3 MD |
17 | struct metadata_packet_header { |
18 | uint32_t magic; /* 0x75D11D57 */ | |
1ec3f75a | 19 | uint8_t uuid[16]; /* Unique Universal Identifier */ |
881833e3 MD |
20 | uint32_t checksum; /* 0 if unused */ |
21 | uint32_t content_size; /* in bits */ | |
22 | uint32_t packet_size; /* in bits */ | |
23 | uint8_t compression_scheme; /* 0 if unused */ | |
24 | uint8_t encryption_scheme; /* 0 if unused */ | |
25 | uint8_t checksum_scheme; /* 0 if unused */ | |
4173df96 MD |
26 | uint8_t major; /* CTF spec major version number */ |
27 | uint8_t minor; /* CTF spec minor version number */ | |
881833e3 MD |
28 | uint8_t header_end[0]; |
29 | }; | |
30 | ||
31 | struct metadata_record_header { | |
32 | uint8_t header_end[0]; /* End of header */ | |
33 | }; | |
34 | ||
35 | static const struct lib_ring_buffer_config client_config; | |
36 | ||
37 | static inline | |
38 | u64 lib_ring_buffer_clock_read(struct channel *chan) | |
39 | { | |
40 | return 0; | |
41 | } | |
42 | ||
43 | static inline | |
44 | unsigned char record_header_size(const struct lib_ring_buffer_config *config, | |
45 | struct channel *chan, size_t offset, | |
64c796d8 | 46 | size_t *pre_header_padding, |
881833e3 MD |
47 | struct lib_ring_buffer_ctx *ctx) |
48 | { | |
49 | return 0; | |
50 | } | |
51 | ||
52 | #include "wrapper/ringbuffer/api.h" | |
53 | ||
54 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
55 | { | |
56 | return 0; | |
57 | } | |
58 | ||
59 | static | |
60 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, | |
61 | struct channel *chan, size_t offset, | |
881833e3 | 62 | size_t *pre_header_padding, |
881833e3 MD |
63 | struct lib_ring_buffer_ctx *ctx) |
64 | { | |
65 | return 0; | |
66 | } | |
67 | ||
68 | /** | |
69 | * client_packet_header_size - called on buffer-switch to a new sub-buffer | |
70 | * | |
71 | * Return header size without padding after the structure. Don't use packed | |
72 | * structure because gcc generates inefficient code on some architectures | |
73 | * (powerpc, mips..) | |
74 | */ | |
75 | static size_t client_packet_header_size(void) | |
76 | { | |
77 | return offsetof(struct metadata_packet_header, header_end); | |
78 | } | |
79 | ||
80 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
81 | unsigned int subbuf_idx) | |
82 | { | |
83 | struct channel *chan = buf->backend.chan; | |
84 | struct metadata_packet_header *header = | |
85 | (struct metadata_packet_header *) | |
86 | lib_ring_buffer_offset_address(&buf->backend, | |
87 | subbuf_idx * chan->backend.subbuf_size); | |
a90917c3 MD |
88 | struct lttng_channel *lttng_chan = channel_get_private(chan); |
89 | struct lttng_session *session = lttng_chan->session; | |
881833e3 MD |
90 | |
91 | header->magic = TSDL_MAGIC_NUMBER; | |
1ec3f75a | 92 | memcpy(header->uuid, session->uuid.b, sizeof(session->uuid)); |
881833e3 MD |
93 | header->checksum = 0; /* 0 if unused */ |
94 | header->content_size = 0xFFFFFFFF; /* in bits, for debugging */ | |
95 | header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */ | |
96 | header->compression_scheme = 0; /* 0 if unused */ | |
97 | header->encryption_scheme = 0; /* 0 if unused */ | |
98 | header->checksum_scheme = 0; /* 0 if unused */ | |
4173df96 MD |
99 | header->major = CTF_SPEC_MAJOR; |
100 | header->minor = CTF_SPEC_MINOR; | |
881833e3 MD |
101 | } |
102 | ||
103 | /* | |
104 | * offset is assumed to never be 0 here : never deliver a completely empty | |
105 | * subbuffer. data_size is between 1 and subbuf_size. | |
106 | */ | |
107 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
108 | unsigned int subbuf_idx, unsigned long data_size) | |
109 | { | |
110 | struct channel *chan = buf->backend.chan; | |
d793d5e1 | 111 | struct metadata_packet_header *header = |
1ec3f75a | 112 | (struct metadata_packet_header *) |
881833e3 MD |
113 | lib_ring_buffer_offset_address(&buf->backend, |
114 | subbuf_idx * chan->backend.subbuf_size); | |
115 | unsigned long records_lost = 0; | |
116 | ||
117 | header->content_size = data_size * CHAR_BIT; /* in bits */ | |
118 | header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */ | |
71c1d843 MD |
119 | /* |
120 | * We do not care about the records lost count, because the metadata | |
121 | * channel waits and retry. | |
122 | */ | |
123 | (void) lib_ring_buffer_get_records_lost_full(&client_config, buf); | |
881833e3 MD |
124 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); |
125 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); | |
126 | WARN_ON_ONCE(records_lost != 0); | |
127 | } | |
128 | ||
129 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
130 | int cpu, const char *name) | |
131 | { | |
132 | return 0; | |
133 | } | |
134 | ||
135 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
136 | { | |
137 | } | |
138 | ||
139 | static const struct lib_ring_buffer_config client_config = { | |
140 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
141 | .cb.record_header_size = client_record_header_size, | |
142 | .cb.subbuffer_header_size = client_packet_header_size, | |
143 | .cb.buffer_begin = client_buffer_begin, | |
144 | .cb.buffer_end = client_buffer_end, | |
145 | .cb.buffer_create = client_buffer_create, | |
146 | .cb.buffer_finalize = client_buffer_finalize, | |
147 | ||
148 | .tsc_bits = 0, | |
149 | .alloc = RING_BUFFER_ALLOC_GLOBAL, | |
150 | .sync = RING_BUFFER_SYNC_GLOBAL, | |
151 | .mode = RING_BUFFER_MODE_TEMPLATE, | |
152 | .backend = RING_BUFFER_PAGE, | |
2db1399a | 153 | .output = RING_BUFFER_OUTPUT_TEMPLATE, |
881833e3 MD |
154 | .oops = RING_BUFFER_OOPS_CONSISTENCY, |
155 | .ipi = RING_BUFFER_IPI_BARRIER, | |
156 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, | |
157 | }; | |
158 | ||
159 | static | |
160 | struct channel *_channel_create(const char *name, | |
a90917c3 | 161 | struct lttng_channel *lttng_chan, void *buf_addr, |
881833e3 MD |
162 | size_t subbuf_size, size_t num_subbuf, |
163 | unsigned int switch_timer_interval, | |
164 | unsigned int read_timer_interval) | |
165 | { | |
a90917c3 | 166 | return channel_create(&client_config, name, lttng_chan, buf_addr, |
881833e3 MD |
167 | subbuf_size, num_subbuf, switch_timer_interval, |
168 | read_timer_interval); | |
169 | } | |
170 | ||
171 | static | |
a90917c3 | 172 | void lttng_channel_destroy(struct channel *chan) |
881833e3 MD |
173 | { |
174 | channel_destroy(chan); | |
175 | } | |
176 | ||
177 | static | |
a90917c3 | 178 | struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan) |
881833e3 MD |
179 | { |
180 | struct lib_ring_buffer *buf; | |
881833e3 | 181 | |
cd4bd11f MD |
182 | buf = channel_get_ring_buffer(&client_config, chan, 0); |
183 | if (!lib_ring_buffer_open_read(buf)) | |
184 | return buf; | |
881833e3 MD |
185 | return NULL; |
186 | } | |
187 | ||
f71ecafa | 188 | static |
a90917c3 | 189 | int lttng_buffer_has_read_closed_stream(struct channel *chan) |
f71ecafa MD |
190 | { |
191 | struct lib_ring_buffer *buf; | |
192 | int cpu; | |
193 | ||
194 | for_each_channel_cpu(cpu, chan) { | |
195 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
196 | if (!atomic_long_read(&buf->active_readers)) | |
197 | return 1; | |
198 | } | |
199 | return 0; | |
200 | } | |
201 | ||
881833e3 | 202 | static |
a90917c3 | 203 | void lttng_buffer_read_close(struct lib_ring_buffer *buf) |
881833e3 MD |
204 | { |
205 | lib_ring_buffer_release_read(buf); | |
881833e3 MD |
206 | } |
207 | ||
c099397a | 208 | static |
a90917c3 | 209 | int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id) |
881833e3 MD |
210 | { |
211 | return lib_ring_buffer_reserve(&client_config, ctx); | |
212 | } | |
213 | ||
c099397a | 214 | static |
a90917c3 | 215 | void lttng_event_commit(struct lib_ring_buffer_ctx *ctx) |
881833e3 MD |
216 | { |
217 | lib_ring_buffer_commit(&client_config, ctx); | |
218 | } | |
219 | ||
c099397a | 220 | static |
a90917c3 | 221 | void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, |
881833e3 MD |
222 | size_t len) |
223 | { | |
224 | lib_ring_buffer_write(&client_config, ctx, src, len); | |
225 | } | |
226 | ||
4ea00e4f | 227 | static |
a90917c3 | 228 | void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx, |
4ea00e4f JD |
229 | const void __user *src, size_t len) |
230 | { | |
231 | lib_ring_buffer_copy_from_user(&client_config, ctx, src, len); | |
232 | } | |
233 | ||
58aa5d24 | 234 | static |
a90917c3 | 235 | void lttng_event_memset(struct lib_ring_buffer_ctx *ctx, |
58aa5d24 MD |
236 | int c, size_t len) |
237 | { | |
238 | lib_ring_buffer_memset(&client_config, ctx, c, len); | |
239 | } | |
240 | ||
1ec3f75a | 241 | static |
a90917c3 | 242 | size_t lttng_packet_avail_size(struct channel *chan) |
1ec3f75a MD |
243 | |
244 | { | |
245 | unsigned long o_begin; | |
246 | struct lib_ring_buffer *buf; | |
247 | ||
248 | buf = chan->backend.buf; /* Only for global buffer ! */ | |
249 | o_begin = v_read(&client_config, &buf->offset); | |
250 | if (subbuf_offset(o_begin, chan) != 0) { | |
251 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan); | |
252 | } else { | |
253 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan) | |
254 | - sizeof(struct metadata_packet_header); | |
255 | } | |
256 | } | |
257 | ||
c099397a | 258 | static |
a90917c3 | 259 | wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu) |
c099397a | 260 | { |
71c1d843 MD |
261 | struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config, |
262 | chan, cpu); | |
263 | return &buf->write_wait; | |
24cedcfe MD |
264 | } |
265 | ||
266 | static | |
a90917c3 | 267 | wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan) |
24cedcfe MD |
268 | { |
269 | return &chan->hp_wait; | |
270 | } | |
271 | ||
272 | static | |
a90917c3 | 273 | int lttng_is_finalized(struct channel *chan) |
24cedcfe MD |
274 | { |
275 | return lib_ring_buffer_channel_is_finalized(chan); | |
c099397a MD |
276 | } |
277 | ||
254ec7bc | 278 | static |
a90917c3 | 279 | int lttng_is_disabled(struct channel *chan) |
254ec7bc MD |
280 | { |
281 | return lib_ring_buffer_channel_is_disabled(chan); | |
282 | } | |
283 | ||
a90917c3 | 284 | static struct lttng_transport lttng_relay_transport = { |
881833e3 MD |
285 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, |
286 | .owner = THIS_MODULE, | |
287 | .ops = { | |
288 | .channel_create = _channel_create, | |
a90917c3 MD |
289 | .channel_destroy = lttng_channel_destroy, |
290 | .buffer_read_open = lttng_buffer_read_open, | |
f71ecafa | 291 | .buffer_has_read_closed_stream = |
a90917c3 MD |
292 | lttng_buffer_has_read_closed_stream, |
293 | .buffer_read_close = lttng_buffer_read_close, | |
294 | .event_reserve = lttng_event_reserve, | |
295 | .event_commit = lttng_event_commit, | |
296 | .event_write_from_user = lttng_event_write_from_user, | |
297 | .event_memset = lttng_event_memset, | |
298 | .event_write = lttng_event_write, | |
299 | .packet_avail_size = lttng_packet_avail_size, | |
300 | .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue, | |
301 | .get_hp_wait_queue = lttng_get_hp_wait_queue, | |
302 | .is_finalized = lttng_is_finalized, | |
303 | .is_disabled = lttng_is_disabled, | |
881833e3 MD |
304 | }, |
305 | }; | |
306 | ||
a90917c3 | 307 | static int __init lttng_ring_buffer_client_init(void) |
881833e3 MD |
308 | { |
309 | /* | |
310 | * This vmalloc sync all also takes care of the lib ring buffer | |
311 | * vmalloc'd module pages when it is built as a module into LTTng. | |
312 | */ | |
313 | wrapper_vmalloc_sync_all(); | |
a90917c3 | 314 | lttng_transport_register(<tng_relay_transport); |
881833e3 MD |
315 | return 0; |
316 | } | |
317 | ||
a90917c3 | 318 | module_init(lttng_ring_buffer_client_init); |
881833e3 | 319 | |
a90917c3 | 320 | static void __exit lttng_ring_buffer_client_exit(void) |
881833e3 | 321 | { |
a90917c3 | 322 | lttng_transport_unregister(<tng_relay_transport); |
881833e3 MD |
323 | } |
324 | ||
a90917c3 | 325 | module_exit(lttng_ring_buffer_client_exit); |
881833e3 MD |
326 | |
327 | MODULE_LICENSE("GPL and additional rights"); | |
328 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
329 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING | |
330 | " client"); |