Commit | Line | Data |
---|---|---|
881833e3 MD |
1 | /* |
2 | * ltt-ring-buffer-client.h | |
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() */ | |
14 | #include "ltt-events.h" | |
15 | #include "ltt-tracer.h" | |
16 | ||
17 | #ifndef CHAR_BIT | |
18 | #define CHAR_BIT 8 | |
19 | #endif | |
20 | ||
21 | struct metadata_packet_header { | |
22 | uint32_t magic; /* 0x75D11D57 */ | |
23 | uint8_t trace_uuid[16]; /* Unique Universal Identifier */ | |
24 | uint32_t checksum; /* 0 if unused */ | |
25 | uint32_t content_size; /* in bits */ | |
26 | uint32_t packet_size; /* in bits */ | |
27 | uint8_t compression_scheme; /* 0 if unused */ | |
28 | uint8_t encryption_scheme; /* 0 if unused */ | |
29 | uint8_t checksum_scheme; /* 0 if unused */ | |
30 | uint8_t header_end[0]; | |
31 | }; | |
32 | ||
33 | struct metadata_record_header { | |
34 | uint8_t header_end[0]; /* End of header */ | |
35 | }; | |
36 | ||
37 | static const struct lib_ring_buffer_config client_config; | |
38 | ||
39 | static inline | |
40 | u64 lib_ring_buffer_clock_read(struct channel *chan) | |
41 | { | |
42 | return 0; | |
43 | } | |
44 | ||
45 | static inline | |
46 | unsigned char record_header_size(const struct lib_ring_buffer_config *config, | |
47 | struct channel *chan, size_t offset, | |
48 | size_t data_size, size_t *pre_header_padding, | |
49 | unsigned int rflags, | |
50 | struct lib_ring_buffer_ctx *ctx) | |
51 | { | |
52 | return 0; | |
53 | } | |
54 | ||
55 | #include "wrapper/ringbuffer/api.h" | |
56 | ||
57 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
58 | { | |
59 | return 0; | |
60 | } | |
61 | ||
62 | static | |
63 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, | |
64 | struct channel *chan, size_t offset, | |
65 | size_t data_size, | |
66 | size_t *pre_header_padding, | |
67 | unsigned int rflags, | |
68 | struct lib_ring_buffer_ctx *ctx) | |
69 | { | |
70 | return 0; | |
71 | } | |
72 | ||
73 | /** | |
74 | * client_packet_header_size - called on buffer-switch to a new sub-buffer | |
75 | * | |
76 | * Return header size without padding after the structure. Don't use packed | |
77 | * structure because gcc generates inefficient code on some architectures | |
78 | * (powerpc, mips..) | |
79 | */ | |
80 | static size_t client_packet_header_size(void) | |
81 | { | |
82 | return offsetof(struct metadata_packet_header, header_end); | |
83 | } | |
84 | ||
85 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
86 | unsigned int subbuf_idx) | |
87 | { | |
88 | struct channel *chan = buf->backend.chan; | |
89 | struct metadata_packet_header *header = | |
90 | (struct metadata_packet_header *) | |
91 | lib_ring_buffer_offset_address(&buf->backend, | |
92 | subbuf_idx * chan->backend.subbuf_size); | |
93 | ||
94 | header->magic = TSDL_MAGIC_NUMBER; | |
95 | /* TODO */ | |
96 | //header->trace_uuid = ; /* Unique Universal Identifier */ | |
97 | header->checksum = 0; /* 0 if unused */ | |
98 | header->content_size = 0xFFFFFFFF; /* in bits, for debugging */ | |
99 | header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */ | |
100 | header->compression_scheme = 0; /* 0 if unused */ | |
101 | header->encryption_scheme = 0; /* 0 if unused */ | |
102 | header->checksum_scheme = 0; /* 0 if unused */ | |
103 | } | |
104 | ||
105 | /* | |
106 | * offset is assumed to never be 0 here : never deliver a completely empty | |
107 | * subbuffer. data_size is between 1 and subbuf_size. | |
108 | */ | |
109 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
110 | unsigned int subbuf_idx, unsigned long data_size) | |
111 | { | |
112 | struct channel *chan = buf->backend.chan; | |
113 | struct packet_header *header = | |
114 | (struct packet_header *) | |
115 | lib_ring_buffer_offset_address(&buf->backend, | |
116 | subbuf_idx * chan->backend.subbuf_size); | |
117 | unsigned long records_lost = 0; | |
118 | ||
119 | header->content_size = data_size * CHAR_BIT; /* in bits */ | |
120 | header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */ | |
121 | records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf); | |
122 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); | |
123 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); | |
124 | WARN_ON_ONCE(records_lost != 0); | |
125 | } | |
126 | ||
127 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
128 | int cpu, const char *name) | |
129 | { | |
130 | return 0; | |
131 | } | |
132 | ||
133 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
134 | { | |
135 | } | |
136 | ||
137 | static const struct lib_ring_buffer_config client_config = { | |
138 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
139 | .cb.record_header_size = client_record_header_size, | |
140 | .cb.subbuffer_header_size = client_packet_header_size, | |
141 | .cb.buffer_begin = client_buffer_begin, | |
142 | .cb.buffer_end = client_buffer_end, | |
143 | .cb.buffer_create = client_buffer_create, | |
144 | .cb.buffer_finalize = client_buffer_finalize, | |
145 | ||
146 | .tsc_bits = 0, | |
147 | .alloc = RING_BUFFER_ALLOC_GLOBAL, | |
148 | .sync = RING_BUFFER_SYNC_GLOBAL, | |
149 | .mode = RING_BUFFER_MODE_TEMPLATE, | |
150 | .backend = RING_BUFFER_PAGE, | |
151 | .output = RING_BUFFER_SPLICE, | |
152 | .oops = RING_BUFFER_OOPS_CONSISTENCY, | |
153 | .ipi = RING_BUFFER_IPI_BARRIER, | |
154 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, | |
155 | }; | |
156 | ||
157 | static | |
158 | struct channel *_channel_create(const char *name, | |
159 | struct ltt_session *session, void *buf_addr, | |
160 | size_t subbuf_size, size_t num_subbuf, | |
161 | unsigned int switch_timer_interval, | |
162 | unsigned int read_timer_interval) | |
163 | { | |
164 | return channel_create(&client_config, name, session, buf_addr, | |
165 | subbuf_size, num_subbuf, switch_timer_interval, | |
166 | read_timer_interval); | |
167 | } | |
168 | ||
169 | static | |
170 | void ltt_channel_destroy(struct channel *chan) | |
171 | { | |
172 | channel_destroy(chan); | |
173 | } | |
174 | ||
175 | static | |
176 | struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan) | |
177 | { | |
178 | struct lib_ring_buffer *buf; | |
179 | int cpu; | |
180 | ||
181 | for_each_channel_cpu(cpu, chan) { | |
182 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
183 | if (!lib_ring_buffer_open_read(buf)) | |
184 | return buf; | |
185 | } | |
186 | return NULL; | |
187 | } | |
188 | ||
189 | static | |
190 | void ltt_buffer_read_close(struct lib_ring_buffer *buf) | |
191 | { | |
192 | lib_ring_buffer_release_read(buf); | |
193 | ||
194 | } | |
195 | ||
196 | int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx) | |
197 | { | |
198 | return lib_ring_buffer_reserve(&client_config, ctx); | |
199 | } | |
200 | ||
201 | void ltt_event_commit(struct lib_ring_buffer_ctx *ctx) | |
202 | { | |
203 | lib_ring_buffer_commit(&client_config, ctx); | |
204 | } | |
205 | ||
206 | void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, | |
207 | size_t len) | |
208 | { | |
209 | lib_ring_buffer_write(&client_config, ctx, src, len); | |
210 | } | |
211 | ||
212 | static struct ltt_transport ltt_relay_transport = { | |
213 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, | |
214 | .owner = THIS_MODULE, | |
215 | .ops = { | |
216 | .channel_create = _channel_create, | |
217 | .channel_destroy = ltt_channel_destroy, | |
218 | .buffer_read_open = ltt_buffer_read_open, | |
219 | .buffer_read_close = ltt_buffer_read_close, | |
220 | .event_reserve = ltt_event_reserve, | |
221 | .event_commit = ltt_event_commit, | |
222 | .event_write = ltt_event_write, | |
223 | }, | |
224 | }; | |
225 | ||
226 | static int __init ltt_ring_buffer_client_init(void) | |
227 | { | |
228 | /* | |
229 | * This vmalloc sync all also takes care of the lib ring buffer | |
230 | * vmalloc'd module pages when it is built as a module into LTTng. | |
231 | */ | |
232 | wrapper_vmalloc_sync_all(); | |
233 | printk(KERN_INFO "LTT : ltt ring buffer metadata client init\n"); | |
234 | ltt_transport_register(<t_relay_transport); | |
235 | return 0; | |
236 | } | |
237 | ||
238 | module_init(ltt_ring_buffer_client_init); | |
239 | ||
240 | static void __exit ltt_ring_buffer_client_exit(void) | |
241 | { | |
242 | printk(KERN_INFO "LTT : ltt ring buffer metadata client exit\n"); | |
243 | ltt_transport_unregister(<t_relay_transport); | |
244 | } | |
245 | ||
246 | module_exit(ltt_ring_buffer_client_exit); | |
247 | ||
248 | MODULE_LICENSE("GPL and additional rights"); | |
249 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
250 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING | |
251 | " client"); |