| 1 | /* |
| 2 | * lttng-ring-buffer-client.h |
| 3 | * |
| 4 | * LTTng lib ring buffer client template. |
| 5 | * |
| 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 |
| 21 | */ |
| 22 | |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/types.h> |
| 25 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ |
| 26 | #include "lttng-events.h" |
| 27 | #include "lttng-tracer.h" |
| 28 | |
| 29 | struct metadata_packet_header { |
| 30 | uint32_t magic; /* 0x75D11D57 */ |
| 31 | uint8_t uuid[16]; /* Unique Universal Identifier */ |
| 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 */ |
| 38 | uint8_t major; /* CTF spec major version number */ |
| 39 | uint8_t minor; /* CTF spec minor version number */ |
| 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, |
| 58 | size_t *pre_header_padding, |
| 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, |
| 74 | size_t *pre_header_padding, |
| 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); |
| 100 | struct lttng_channel *lttng_chan = channel_get_private(chan); |
| 101 | struct lttng_session *session = lttng_chan->session; |
| 102 | |
| 103 | header->magic = TSDL_MAGIC_NUMBER; |
| 104 | memcpy(header->uuid, session->uuid.b, sizeof(session->uuid)); |
| 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 */ |
| 111 | header->major = CTF_SPEC_MAJOR; |
| 112 | header->minor = CTF_SPEC_MINOR; |
| 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; |
| 123 | struct metadata_packet_header *header = |
| 124 | (struct metadata_packet_header *) |
| 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 */ |
| 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); |
| 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, |
| 165 | .output = RING_BUFFER_OUTPUT_TEMPLATE, |
| 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, |
| 173 | struct lttng_channel *lttng_chan, void *buf_addr, |
| 174 | size_t subbuf_size, size_t num_subbuf, |
| 175 | unsigned int switch_timer_interval, |
| 176 | unsigned int read_timer_interval) |
| 177 | { |
| 178 | return channel_create(&client_config, name, lttng_chan, buf_addr, |
| 179 | subbuf_size, num_subbuf, switch_timer_interval, |
| 180 | read_timer_interval); |
| 181 | } |
| 182 | |
| 183 | static |
| 184 | void lttng_channel_destroy(struct channel *chan) |
| 185 | { |
| 186 | channel_destroy(chan); |
| 187 | } |
| 188 | |
| 189 | static |
| 190 | struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan) |
| 191 | { |
| 192 | struct lib_ring_buffer *buf; |
| 193 | |
| 194 | buf = channel_get_ring_buffer(&client_config, chan, 0); |
| 195 | if (!lib_ring_buffer_open_read(buf)) |
| 196 | return buf; |
| 197 | return NULL; |
| 198 | } |
| 199 | |
| 200 | static |
| 201 | int lttng_buffer_has_read_closed_stream(struct channel *chan) |
| 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 | |
| 214 | static |
| 215 | void lttng_buffer_read_close(struct lib_ring_buffer *buf) |
| 216 | { |
| 217 | lib_ring_buffer_release_read(buf); |
| 218 | } |
| 219 | |
| 220 | static |
| 221 | int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id) |
| 222 | { |
| 223 | return lib_ring_buffer_reserve(&client_config, ctx); |
| 224 | } |
| 225 | |
| 226 | static |
| 227 | void lttng_event_commit(struct lib_ring_buffer_ctx *ctx) |
| 228 | { |
| 229 | lib_ring_buffer_commit(&client_config, ctx); |
| 230 | } |
| 231 | |
| 232 | static |
| 233 | void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, |
| 234 | size_t len) |
| 235 | { |
| 236 | lib_ring_buffer_write(&client_config, ctx, src, len); |
| 237 | } |
| 238 | |
| 239 | static |
| 240 | void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx, |
| 241 | const void __user *src, size_t len) |
| 242 | { |
| 243 | lib_ring_buffer_copy_from_user(&client_config, ctx, src, len); |
| 244 | } |
| 245 | |
| 246 | static |
| 247 | void lttng_event_memset(struct lib_ring_buffer_ctx *ctx, |
| 248 | int c, size_t len) |
| 249 | { |
| 250 | lib_ring_buffer_memset(&client_config, ctx, c, len); |
| 251 | } |
| 252 | |
| 253 | static |
| 254 | size_t lttng_packet_avail_size(struct channel *chan) |
| 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 | |
| 270 | static |
| 271 | wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu) |
| 272 | { |
| 273 | struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config, |
| 274 | chan, cpu); |
| 275 | return &buf->write_wait; |
| 276 | } |
| 277 | |
| 278 | static |
| 279 | wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan) |
| 280 | { |
| 281 | return &chan->hp_wait; |
| 282 | } |
| 283 | |
| 284 | static |
| 285 | int lttng_is_finalized(struct channel *chan) |
| 286 | { |
| 287 | return lib_ring_buffer_channel_is_finalized(chan); |
| 288 | } |
| 289 | |
| 290 | static |
| 291 | int lttng_is_disabled(struct channel *chan) |
| 292 | { |
| 293 | return lib_ring_buffer_channel_is_disabled(chan); |
| 294 | } |
| 295 | |
| 296 | static struct lttng_transport lttng_relay_transport = { |
| 297 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, |
| 298 | .owner = THIS_MODULE, |
| 299 | .ops = { |
| 300 | .channel_create = _channel_create, |
| 301 | .channel_destroy = lttng_channel_destroy, |
| 302 | .buffer_read_open = lttng_buffer_read_open, |
| 303 | .buffer_has_read_closed_stream = |
| 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, |
| 316 | }, |
| 317 | }; |
| 318 | |
| 319 | static int __init lttng_ring_buffer_client_init(void) |
| 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(); |
| 326 | lttng_transport_register(<tng_relay_transport); |
| 327 | return 0; |
| 328 | } |
| 329 | |
| 330 | module_init(lttng_ring_buffer_client_init); |
| 331 | |
| 332 | static void __exit lttng_ring_buffer_client_exit(void) |
| 333 | { |
| 334 | lttng_transport_unregister(<tng_relay_transport); |
| 335 | } |
| 336 | |
| 337 | module_exit(lttng_ring_buffer_client_exit); |
| 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"); |