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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 | ||
881833e3 MD |
17 | struct metadata_packet_header { |
18 | uint32_t magic; /* 0x75D11D57 */ | |
19 | uint8_t trace_uuid[16]; /* Unique Universal Identifier */ | |
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 */ | |
26 | uint8_t header_end[0]; | |
27 | }; | |
28 | ||
29 | struct metadata_record_header { | |
30 | uint8_t header_end[0]; /* End of header */ | |
31 | }; | |
32 | ||
33 | static const struct lib_ring_buffer_config client_config; | |
34 | ||
35 | static inline | |
36 | u64 lib_ring_buffer_clock_read(struct channel *chan) | |
37 | { | |
38 | return 0; | |
39 | } | |
40 | ||
41 | static inline | |
42 | unsigned char record_header_size(const struct lib_ring_buffer_config *config, | |
43 | struct channel *chan, size_t offset, | |
44 | size_t data_size, size_t *pre_header_padding, | |
45 | unsigned int rflags, | |
46 | struct lib_ring_buffer_ctx *ctx) | |
47 | { | |
48 | return 0; | |
49 | } | |
50 | ||
51 | #include "wrapper/ringbuffer/api.h" | |
52 | ||
53 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
54 | { | |
55 | return 0; | |
56 | } | |
57 | ||
58 | static | |
59 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, | |
60 | struct channel *chan, size_t offset, | |
61 | size_t data_size, | |
62 | size_t *pre_header_padding, | |
63 | unsigned int rflags, | |
64 | struct lib_ring_buffer_ctx *ctx) | |
65 | { | |
66 | return 0; | |
67 | } | |
68 | ||
69 | /** | |
70 | * client_packet_header_size - called on buffer-switch to a new sub-buffer | |
71 | * | |
72 | * Return header size without padding after the structure. Don't use packed | |
73 | * structure because gcc generates inefficient code on some architectures | |
74 | * (powerpc, mips..) | |
75 | */ | |
76 | static size_t client_packet_header_size(void) | |
77 | { | |
78 | return offsetof(struct metadata_packet_header, header_end); | |
79 | } | |
80 | ||
81 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
82 | unsigned int subbuf_idx) | |
83 | { | |
84 | struct channel *chan = buf->backend.chan; | |
85 | struct metadata_packet_header *header = | |
86 | (struct metadata_packet_header *) | |
87 | lib_ring_buffer_offset_address(&buf->backend, | |
88 | subbuf_idx * chan->backend.subbuf_size); | |
89 | ||
90 | header->magic = TSDL_MAGIC_NUMBER; | |
91 | /* TODO */ | |
92 | //header->trace_uuid = ; /* Unique Universal Identifier */ | |
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 */ | |
99 | } | |
100 | ||
101 | /* | |
102 | * offset is assumed to never be 0 here : never deliver a completely empty | |
103 | * subbuffer. data_size is between 1 and subbuf_size. | |
104 | */ | |
105 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
106 | unsigned int subbuf_idx, unsigned long data_size) | |
107 | { | |
108 | struct channel *chan = buf->backend.chan; | |
109 | struct packet_header *header = | |
110 | (struct packet_header *) | |
111 | lib_ring_buffer_offset_address(&buf->backend, | |
112 | subbuf_idx * chan->backend.subbuf_size); | |
113 | unsigned long records_lost = 0; | |
114 | ||
115 | header->content_size = data_size * CHAR_BIT; /* in bits */ | |
116 | header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */ | |
117 | records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf); | |
118 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); | |
119 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); | |
120 | WARN_ON_ONCE(records_lost != 0); | |
121 | } | |
122 | ||
123 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
124 | int cpu, const char *name) | |
125 | { | |
126 | return 0; | |
127 | } | |
128 | ||
129 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
130 | { | |
131 | } | |
132 | ||
133 | static const struct lib_ring_buffer_config client_config = { | |
134 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
135 | .cb.record_header_size = client_record_header_size, | |
136 | .cb.subbuffer_header_size = client_packet_header_size, | |
137 | .cb.buffer_begin = client_buffer_begin, | |
138 | .cb.buffer_end = client_buffer_end, | |
139 | .cb.buffer_create = client_buffer_create, | |
140 | .cb.buffer_finalize = client_buffer_finalize, | |
141 | ||
142 | .tsc_bits = 0, | |
143 | .alloc = RING_BUFFER_ALLOC_GLOBAL, | |
144 | .sync = RING_BUFFER_SYNC_GLOBAL, | |
145 | .mode = RING_BUFFER_MODE_TEMPLATE, | |
146 | .backend = RING_BUFFER_PAGE, | |
147 | .output = RING_BUFFER_SPLICE, | |
148 | .oops = RING_BUFFER_OOPS_CONSISTENCY, | |
149 | .ipi = RING_BUFFER_IPI_BARRIER, | |
150 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, | |
151 | }; | |
152 | ||
153 | static | |
154 | struct channel *_channel_create(const char *name, | |
155 | struct ltt_session *session, void *buf_addr, | |
156 | size_t subbuf_size, size_t num_subbuf, | |
157 | unsigned int switch_timer_interval, | |
158 | unsigned int read_timer_interval) | |
159 | { | |
160 | return channel_create(&client_config, name, session, buf_addr, | |
161 | subbuf_size, num_subbuf, switch_timer_interval, | |
162 | read_timer_interval); | |
163 | } | |
164 | ||
165 | static | |
166 | void ltt_channel_destroy(struct channel *chan) | |
167 | { | |
168 | channel_destroy(chan); | |
169 | } | |
170 | ||
171 | static | |
172 | struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan) | |
173 | { | |
174 | struct lib_ring_buffer *buf; | |
175 | int cpu; | |
176 | ||
177 | for_each_channel_cpu(cpu, chan) { | |
178 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
179 | if (!lib_ring_buffer_open_read(buf)) | |
180 | return buf; | |
181 | } | |
182 | return NULL; | |
183 | } | |
184 | ||
185 | static | |
186 | void ltt_buffer_read_close(struct lib_ring_buffer *buf) | |
187 | { | |
188 | lib_ring_buffer_release_read(buf); | |
189 | ||
190 | } | |
191 | ||
c099397a | 192 | static |
881833e3 MD |
193 | int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx) |
194 | { | |
195 | return lib_ring_buffer_reserve(&client_config, ctx); | |
196 | } | |
197 | ||
c099397a | 198 | static |
881833e3 MD |
199 | void ltt_event_commit(struct lib_ring_buffer_ctx *ctx) |
200 | { | |
201 | lib_ring_buffer_commit(&client_config, ctx); | |
202 | } | |
203 | ||
c099397a | 204 | static |
881833e3 MD |
205 | void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, |
206 | size_t len) | |
207 | { | |
208 | lib_ring_buffer_write(&client_config, ctx, src, len); | |
209 | } | |
210 | ||
c099397a MD |
211 | static |
212 | wait_queue_head_t *ltt_get_reader_wait_queue(struct ltt_channel *chan) | |
213 | { | |
214 | return &chan->chan->read_wait; | |
215 | } | |
216 | ||
881833e3 MD |
217 | static struct ltt_transport ltt_relay_transport = { |
218 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, | |
219 | .owner = THIS_MODULE, | |
220 | .ops = { | |
221 | .channel_create = _channel_create, | |
222 | .channel_destroy = ltt_channel_destroy, | |
223 | .buffer_read_open = ltt_buffer_read_open, | |
224 | .buffer_read_close = ltt_buffer_read_close, | |
225 | .event_reserve = ltt_event_reserve, | |
226 | .event_commit = ltt_event_commit, | |
227 | .event_write = ltt_event_write, | |
c099397a | 228 | .get_reader_wait_queue = ltt_get_reader_wait_queue, |
881833e3 MD |
229 | }, |
230 | }; | |
231 | ||
232 | static int __init ltt_ring_buffer_client_init(void) | |
233 | { | |
234 | /* | |
235 | * This vmalloc sync all also takes care of the lib ring buffer | |
236 | * vmalloc'd module pages when it is built as a module into LTTng. | |
237 | */ | |
238 | wrapper_vmalloc_sync_all(); | |
239 | printk(KERN_INFO "LTT : ltt ring buffer metadata client init\n"); | |
240 | ltt_transport_register(<t_relay_transport); | |
241 | return 0; | |
242 | } | |
243 | ||
244 | module_init(ltt_ring_buffer_client_init); | |
245 | ||
246 | static void __exit ltt_ring_buffer_client_exit(void) | |
247 | { | |
248 | printk(KERN_INFO "LTT : ltt ring buffer metadata client exit\n"); | |
249 | ltt_transport_unregister(<t_relay_transport); | |
250 | } | |
251 | ||
252 | module_exit(ltt_ring_buffer_client_exit); | |
253 | ||
254 | MODULE_LICENSE("GPL and additional rights"); | |
255 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
256 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING | |
257 | " client"); |