Karthikeyan Ramasubramanian | e1f4f73 | 2011-08-08 13:34:47 -0600 | [diff] [blame] | 1 | /* Copyright (c) 2012, Code Aurora Forum. All rights reserved. |
| 2 | * |
| 3 | * This program is free software; you can redistribute it and/or modify |
| 4 | * it under the terms of the GNU General Public License version 2 and |
| 5 | * only version 2 as published by the Free Software Foundation. |
| 6 | * |
| 7 | * This program is distributed in the hope that it will be useful, |
| 8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 10 | * GNU General Public License for more details. |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/uaccess.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/errno.h> |
| 20 | #include <linux/jiffies.h> |
| 21 | #include <linux/debugfs.h> |
| 22 | #include <linux/io.h> |
| 23 | #include <linux/idr.h> |
| 24 | #include <linux/string.h> |
| 25 | #include <linux/sched.h> |
| 26 | #include <linux/wait.h> |
| 27 | #include <linux/delay.h> |
| 28 | #include <linux/completion.h> |
| 29 | |
| 30 | #include <mach/msm_ipc_logging.h> |
| 31 | |
| 32 | #include "ipc_logging.h" |
| 33 | |
| 34 | static LIST_HEAD(ipc_log_context_list); |
| 35 | DEFINE_SPINLOCK(ipc_log_context_list_lock); |
| 36 | static atomic_t next_log_id = ATOMIC_INIT(0); |
| 37 | |
| 38 | static struct ipc_log_page *get_first_page(struct ipc_log_context *ilctxt) |
| 39 | { |
| 40 | struct ipc_log_page_header *p_pghdr; |
| 41 | struct ipc_log_page *pg = NULL; |
| 42 | |
| 43 | if (!ilctxt) |
| 44 | return NULL; |
| 45 | p_pghdr = list_first_entry(&ilctxt->page_list, |
| 46 | struct ipc_log_page_header, list); |
| 47 | pg = container_of(p_pghdr, struct ipc_log_page, hdr); |
| 48 | return pg; |
| 49 | } |
| 50 | |
| 51 | static struct ipc_log_page *get_next_page(struct ipc_log_context *ilctxt, |
| 52 | struct ipc_log_page *cur_pg) |
| 53 | { |
| 54 | struct ipc_log_page_header *p_pghdr; |
| 55 | struct ipc_log_page *pg = NULL; |
| 56 | |
| 57 | if (!ilctxt || !cur_pg) |
| 58 | return NULL; |
| 59 | |
| 60 | if (ilctxt->last_page == cur_pg) |
| 61 | return ilctxt->first_page; |
| 62 | |
| 63 | p_pghdr = list_first_entry(&cur_pg->hdr.list, |
| 64 | struct ipc_log_page_header, list); |
| 65 | pg = container_of(p_pghdr, struct ipc_log_page, hdr); |
| 66 | |
| 67 | return pg; |
| 68 | } |
| 69 | |
| 70 | /* If data == NULL, drop the log of size data_size*/ |
| 71 | static void ipc_log_read(struct ipc_log_context *ilctxt, |
| 72 | void *data, int data_size) |
| 73 | { |
| 74 | int bytes_to_read; |
| 75 | |
| 76 | bytes_to_read = MIN(((PAGE_SIZE - sizeof(struct ipc_log_page_header)) |
| 77 | - ilctxt->read_page->hdr.read_offset), |
| 78 | data_size); |
| 79 | if (data) |
| 80 | memcpy(data, (ilctxt->read_page->data + |
| 81 | ilctxt->read_page->hdr.read_offset), bytes_to_read); |
| 82 | if (bytes_to_read != data_size) { |
| 83 | ilctxt->read_page->hdr.read_offset = 0xFFFF; |
| 84 | ilctxt->read_page = get_next_page(ilctxt, ilctxt->read_page); |
| 85 | ilctxt->read_page->hdr.read_offset = 0; |
| 86 | if (data) |
| 87 | memcpy((data + bytes_to_read), |
| 88 | (ilctxt->read_page->data + |
| 89 | ilctxt->read_page->hdr.read_offset), |
| 90 | (data_size - bytes_to_read)); |
| 91 | bytes_to_read = (data_size - bytes_to_read); |
| 92 | } |
| 93 | ilctxt->read_page->hdr.read_offset += bytes_to_read; |
| 94 | ilctxt->write_avail += data_size; |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Reads a message. |
| 99 | * |
| 100 | * If a message is read successfully, then the the message context |
| 101 | * will be set to: |
| 102 | * .hdr message header .size and .type values |
| 103 | * .offset beginning of message data |
| 104 | * |
| 105 | * @ectxt Message context and if NULL, drops the message. |
| 106 | * |
| 107 | * @returns 0 - no message available |
| 108 | * 1 - message read |
| 109 | */ |
| 110 | int msg_read(struct ipc_log_context *ilctxt, |
| 111 | struct encode_context *ectxt) |
| 112 | { |
| 113 | struct tsv_header hdr; |
| 114 | |
| 115 | ipc_log_read(ilctxt, &hdr, sizeof(hdr)); |
| 116 | if (ectxt) { |
| 117 | ectxt->hdr.type = hdr.type; |
| 118 | ectxt->hdr.size = hdr.size; |
| 119 | ectxt->offset = sizeof(hdr); |
| 120 | ipc_log_read(ilctxt, (ectxt->buff + ectxt->offset), |
| 121 | (int)hdr.size); |
| 122 | } else { |
| 123 | ipc_log_read(ilctxt, NULL, (int)hdr.size); |
| 124 | } |
| 125 | return sizeof(hdr) + (int)hdr.size; |
| 126 | } |
| 127 | |
| 128 | /* |
| 129 | * Commits messages to the FIFO. If the FIFO is full, then enough |
| 130 | * messages are dropped to create space for the new message. |
| 131 | */ |
| 132 | void ipc_log_write(void *ctxt, struct encode_context *ectxt) |
| 133 | { |
| 134 | struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt; |
| 135 | int bytes_to_write; |
| 136 | unsigned long flags; |
| 137 | |
| 138 | if (!ilctxt || !ectxt) { |
| 139 | pr_err("%s: Invalid ipc_log or encode context\n", __func__); |
| 140 | return; |
| 141 | } |
| 142 | |
| 143 | spin_lock_irqsave(&ipc_log_context_list_lock, flags); |
| 144 | spin_lock(&ilctxt->ipc_log_context_lock); |
| 145 | while (ilctxt->write_avail < ectxt->offset) |
| 146 | msg_read(ilctxt, NULL); |
| 147 | |
| 148 | bytes_to_write = MIN(((PAGE_SIZE - sizeof(struct ipc_log_page_header)) |
| 149 | - ilctxt->write_page->hdr.write_offset), |
| 150 | ectxt->offset); |
| 151 | memcpy((ilctxt->write_page->data + |
| 152 | ilctxt->write_page->hdr.write_offset), |
| 153 | ectxt->buff, bytes_to_write); |
| 154 | if (bytes_to_write != ectxt->offset) { |
| 155 | ilctxt->write_page->hdr.write_offset = 0xFFFF; |
| 156 | ilctxt->write_page = get_next_page(ilctxt, ilctxt->write_page); |
| 157 | ilctxt->write_page->hdr.write_offset = 0; |
| 158 | memcpy((ilctxt->write_page->data + |
| 159 | ilctxt->write_page->hdr.write_offset), |
| 160 | (ectxt->buff + bytes_to_write), |
| 161 | (ectxt->offset - bytes_to_write)); |
| 162 | bytes_to_write = (ectxt->offset - bytes_to_write); |
| 163 | } |
| 164 | ilctxt->write_page->hdr.write_offset += bytes_to_write; |
| 165 | ilctxt->write_avail -= ectxt->offset; |
| 166 | complete(&ilctxt->read_avail); |
| 167 | spin_unlock(&ilctxt->ipc_log_context_lock); |
| 168 | spin_unlock_irqrestore(&ipc_log_context_list_lock, flags); |
| 169 | } |
| 170 | EXPORT_SYMBOL(ipc_log_write); |
| 171 | |
| 172 | /* |
| 173 | * Starts a new message after which you can add serialized data and |
| 174 | * then complete the message by calling msg_encode_end(). |
| 175 | */ |
| 176 | void msg_encode_start(struct encode_context *ectxt, uint32_t type) |
| 177 | { |
| 178 | if (!ectxt) { |
| 179 | pr_err("%s: Invalid encode context\n", __func__); |
| 180 | return; |
| 181 | } |
| 182 | |
| 183 | ectxt->hdr.type = type; |
| 184 | ectxt->hdr.size = 0; |
| 185 | ectxt->offset = sizeof(ectxt->hdr); |
| 186 | } |
| 187 | EXPORT_SYMBOL(msg_encode_start); |
| 188 | |
| 189 | /* |
| 190 | * Completes the message |
| 191 | */ |
| 192 | void msg_encode_end(struct encode_context *ectxt) |
| 193 | { |
| 194 | if (!ectxt) { |
| 195 | pr_err("%s: Invalid encode context\n", __func__); |
| 196 | return; |
| 197 | } |
| 198 | |
| 199 | /* finalize data size */ |
| 200 | ectxt->hdr.size = ectxt->offset - sizeof(ectxt->hdr); |
| 201 | BUG_ON(ectxt->hdr.size > MAX_MSG_SIZE); |
| 202 | memcpy(ectxt->buff, &ectxt->hdr, sizeof(ectxt->hdr)); |
| 203 | } |
| 204 | EXPORT_SYMBOL(msg_encode_end); |
| 205 | |
| 206 | /* |
| 207 | * Helper funtion used to write data to a message context. |
| 208 | * |
| 209 | * @ectxt context initialized by calling msg_encode_start() |
| 210 | * @data data to write |
| 211 | * @size number of bytes of data to write |
| 212 | */ |
| 213 | static inline int tsv_write_data(struct encode_context *ectxt, |
| 214 | void *data, uint32_t size) |
| 215 | { |
| 216 | if (!ectxt) { |
| 217 | pr_err("%s: Invalid encode context\n", __func__); |
| 218 | return -EINVAL; |
| 219 | } |
| 220 | if ((ectxt->offset + size) > MAX_MSG_SIZE) { |
| 221 | pr_err("%s: No space to encode further\n", __func__); |
| 222 | return -EINVAL; |
| 223 | } |
| 224 | |
| 225 | memcpy((void *)(ectxt->buff + ectxt->offset), data, size); |
| 226 | ectxt->offset += size; |
| 227 | return 0; |
| 228 | } |
| 229 | |
| 230 | /* |
| 231 | * Helper function that writes a type to the context. |
| 232 | * |
| 233 | * @ectxt context initialized by calling msg_encode_start() |
| 234 | * @type primitive type |
| 235 | * @size size of primitive in bytes |
| 236 | */ |
| 237 | static inline int tsv_write_header(struct encode_context *ectxt, |
| 238 | uint32_t type, uint32_t size) |
| 239 | { |
| 240 | struct tsv_header hdr; |
| 241 | |
| 242 | hdr.type = (unsigned char)type; |
| 243 | hdr.size = (unsigned char)size; |
| 244 | return tsv_write_data(ectxt, &hdr, sizeof(hdr)); |
| 245 | } |
| 246 | |
| 247 | /* |
| 248 | * Writes the current timestamp count. |
| 249 | * |
| 250 | * @ectxt context initialized by calling msg_encode_start() |
| 251 | */ |
| 252 | int tsv_timestamp_write(struct encode_context *ectxt) |
| 253 | { |
| 254 | int ret; |
| 255 | unsigned long long t_now = sched_clock(); |
| 256 | |
| 257 | ret = tsv_write_header(ectxt, TSV_TYPE_TIMESTAMP, sizeof(t_now)); |
| 258 | if (ret) |
| 259 | return ret; |
| 260 | return tsv_write_data(ectxt, &t_now, sizeof(t_now)); |
| 261 | } |
| 262 | EXPORT_SYMBOL(tsv_timestamp_write); |
| 263 | |
| 264 | /* |
| 265 | * Writes a data pointer. |
| 266 | * |
| 267 | * @ectxt context initialized by calling msg_encode_start() |
| 268 | * @pointer pointer value to write |
| 269 | */ |
| 270 | int tsv_pointer_write(struct encode_context *ectxt, void *pointer) |
| 271 | { |
| 272 | int ret; |
| 273 | ret = tsv_write_header(ectxt, TSV_TYPE_POINTER, sizeof(pointer)); |
| 274 | if (ret) |
| 275 | return ret; |
| 276 | return tsv_write_data(ectxt, &pointer, sizeof(pointer)); |
| 277 | } |
| 278 | EXPORT_SYMBOL(tsv_pointer_write); |
| 279 | |
| 280 | /* |
| 281 | * Writes a 32-bit integer value. |
| 282 | * |
| 283 | * @ectxt context initialized by calling msg_encode_start() |
| 284 | * @n integer to write |
| 285 | */ |
| 286 | int tsv_int32_write(struct encode_context *ectxt, int32_t n) |
| 287 | { |
| 288 | int ret; |
| 289 | ret = tsv_write_header(ectxt, TSV_TYPE_INT32, sizeof(n)); |
| 290 | if (ret) |
| 291 | return ret; |
| 292 | return tsv_write_data(ectxt, &n, sizeof(n)); |
| 293 | } |
| 294 | EXPORT_SYMBOL(tsv_int32_write); |
| 295 | |
| 296 | /* |
| 297 | * Writes a byte array. |
| 298 | * |
| 299 | * @ectxt context initialized by calling msg_write_start() |
| 300 | * @data Beginning address of data |
| 301 | * @data_size Size of data to be written |
| 302 | */ |
| 303 | int tsv_byte_array_write(struct encode_context *ectxt, |
| 304 | void *data, int data_size) |
| 305 | { |
| 306 | int ret; |
| 307 | ret = tsv_write_header(ectxt, TSV_TYPE_BYTE_ARRAY, data_size); |
| 308 | if (ret) |
| 309 | return ret; |
| 310 | return tsv_write_data(ectxt, data, data_size); |
| 311 | } |
| 312 | EXPORT_SYMBOL(tsv_byte_array_write); |
| 313 | |
| 314 | /* |
| 315 | * Helper function to log a string |
| 316 | * |
| 317 | * @ilctxt ipc_log_context created using ipc_log_context_create() |
| 318 | * @fmt Data specified using format specifiers |
| 319 | */ |
| 320 | int ipc_log_string(void *ilctxt, const char *fmt, ...) |
| 321 | { |
| 322 | struct encode_context ectxt; |
| 323 | int avail_size, data_size, hdr_size = sizeof(struct tsv_header); |
| 324 | va_list arg_list; |
| 325 | |
| 326 | if (!ilctxt) |
| 327 | return -EINVAL; |
| 328 | |
| 329 | msg_encode_start(&ectxt, TSV_TYPE_STRING); |
| 330 | tsv_timestamp_write(&ectxt); |
| 331 | avail_size = (MAX_MSG_SIZE - (ectxt.offset + hdr_size)); |
| 332 | va_start(arg_list, fmt); |
| 333 | data_size = vsnprintf((ectxt.buff + ectxt.offset + hdr_size), |
| 334 | avail_size, fmt, arg_list); |
| 335 | va_end(arg_list); |
| 336 | tsv_write_header(&ectxt, TSV_TYPE_BYTE_ARRAY, data_size); |
| 337 | ectxt.offset += data_size; |
| 338 | msg_encode_end(&ectxt); |
| 339 | ipc_log_write(ilctxt, &ectxt); |
| 340 | return 0; |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * Helper funtion used to read data from a message context. |
| 345 | * |
| 346 | * @ectxt context initialized by calling msg_read() |
| 347 | * @data data to read |
| 348 | * @size number of bytes of data to read |
| 349 | */ |
| 350 | static void tsv_read_data(struct encode_context *ectxt, |
| 351 | void *data, uint32_t size) |
| 352 | { |
| 353 | BUG_ON((ectxt->offset + size) > MAX_MSG_SIZE); |
| 354 | memcpy(data, (ectxt->buff + ectxt->offset), size); |
| 355 | ectxt->offset += size; |
| 356 | } |
| 357 | |
| 358 | /* |
| 359 | * Helper function that reads a type from the context and updates the |
| 360 | * context pointers. |
| 361 | * |
| 362 | * @ectxt context initialized by calling msg_read() |
| 363 | * @hdr type header |
| 364 | */ |
| 365 | static void tsv_read_header(struct encode_context *ectxt, |
| 366 | struct tsv_header *hdr) |
| 367 | { |
| 368 | BUG_ON((ectxt->offset + sizeof(*hdr)) > MAX_MSG_SIZE); |
| 369 | memcpy(hdr, (ectxt->buff + ectxt->offset), sizeof(*hdr)); |
| 370 | ectxt->offset += sizeof(*hdr); |
| 371 | } |
| 372 | |
| 373 | /* |
| 374 | * Reads a timestamp. |
| 375 | * |
| 376 | * @ectxt context initialized by calling msg_read() |
| 377 | * @dctxt deserialization context |
| 378 | * @format output format (appended to %6u.%09u timestamp format) |
| 379 | */ |
| 380 | void tsv_timestamp_read(struct encode_context *ectxt, |
| 381 | struct decode_context *dctxt, const char *format) |
| 382 | { |
| 383 | struct tsv_header hdr; |
| 384 | unsigned long long val; |
| 385 | unsigned long nanosec_rem; |
| 386 | |
| 387 | tsv_read_header(ectxt, &hdr); |
| 388 | BUG_ON(hdr.type != TSV_TYPE_TIMESTAMP); |
| 389 | tsv_read_data(ectxt, &val, sizeof(val)); |
| 390 | nanosec_rem = do_div(val, 1000000000U); |
| 391 | IPC_SPRINTF_DECODE(dctxt, "[%6u.%09lu]%s", |
| 392 | (unsigned)val, nanosec_rem, format); |
| 393 | } |
| 394 | EXPORT_SYMBOL(tsv_timestamp_read); |
| 395 | |
| 396 | /* |
| 397 | * Reads a data pointer. |
| 398 | * |
| 399 | * @ectxt context initialized by calling msg_read() |
| 400 | * @dctxt deserialization context |
| 401 | * @format output format |
| 402 | */ |
| 403 | void tsv_pointer_read(struct encode_context *ectxt, |
| 404 | struct decode_context *dctxt, const char *format) |
| 405 | { |
| 406 | struct tsv_header hdr; |
| 407 | void *val; |
| 408 | |
| 409 | tsv_read_header(ectxt, &hdr); |
| 410 | BUG_ON(hdr.type != TSV_TYPE_POINTER); |
| 411 | tsv_read_data(ectxt, &val, sizeof(val)); |
| 412 | |
| 413 | IPC_SPRINTF_DECODE(dctxt, format, val); |
| 414 | } |
| 415 | EXPORT_SYMBOL(tsv_pointer_read); |
| 416 | |
| 417 | /* |
| 418 | * Reads a 32-bit integer value. |
| 419 | * |
| 420 | * @ectxt context initialized by calling msg_read() |
| 421 | * @dctxt deserialization context |
| 422 | * @format output format |
| 423 | */ |
| 424 | int32_t tsv_int32_read(struct encode_context *ectxt, |
| 425 | struct decode_context *dctxt, const char *format) |
| 426 | { |
| 427 | struct tsv_header hdr; |
| 428 | int32_t val; |
| 429 | |
| 430 | tsv_read_header(ectxt, &hdr); |
| 431 | BUG_ON(hdr.type != TSV_TYPE_INT32); |
| 432 | tsv_read_data(ectxt, &val, sizeof(val)); |
| 433 | |
| 434 | IPC_SPRINTF_DECODE(dctxt, format, val); |
| 435 | return val; |
| 436 | } |
| 437 | EXPORT_SYMBOL(tsv_int32_read); |
| 438 | |
| 439 | /* |
| 440 | * Reads a byte array/string. |
| 441 | * |
| 442 | * @ectxt context initialized by calling msg_read() |
| 443 | * @dctxt deserialization context |
| 444 | * @format output format |
| 445 | */ |
| 446 | void tsv_byte_array_read(struct encode_context *ectxt, |
| 447 | struct decode_context *dctxt, const char *format) |
| 448 | { |
| 449 | struct tsv_header hdr; |
| 450 | |
| 451 | tsv_read_header(ectxt, &hdr); |
| 452 | BUG_ON(hdr.type != TSV_TYPE_BYTE_ARRAY); |
| 453 | tsv_read_data(ectxt, dctxt->buff, hdr.size); |
| 454 | dctxt->buff += hdr.size; |
| 455 | dctxt->size -= hdr.size; |
| 456 | } |
| 457 | EXPORT_SYMBOL(tsv_byte_array_read); |
| 458 | |
| 459 | int add_deserialization_func(void *ctxt, int type, |
| 460 | void (*dfunc)(struct encode_context *, |
| 461 | struct decode_context *)) |
| 462 | { |
| 463 | struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt; |
| 464 | struct dfunc_info *df_info; |
| 465 | unsigned long flags; |
| 466 | |
| 467 | if (!ilctxt || !dfunc) |
| 468 | return -EINVAL; |
| 469 | |
| 470 | df_info = kmalloc(sizeof(struct dfunc_info), GFP_KERNEL); |
| 471 | if (!df_info) |
| 472 | return -ENOSPC; |
| 473 | |
| 474 | spin_lock_irqsave(&ipc_log_context_list_lock, flags); |
| 475 | spin_lock(&ilctxt->ipc_log_context_lock); |
| 476 | df_info->type = type; |
| 477 | df_info->dfunc = dfunc; |
| 478 | list_add_tail(&df_info->list, &ilctxt->dfunc_info_list); |
| 479 | spin_unlock(&ilctxt->ipc_log_context_lock); |
| 480 | spin_unlock_irqrestore(&ipc_log_context_list_lock, flags); |
| 481 | return 0; |
| 482 | } |
| 483 | EXPORT_SYMBOL(add_deserialization_func); |
| 484 | |
| 485 | void *ipc_log_context_create(int max_num_pages, |
| 486 | const char *mod_name) |
| 487 | { |
| 488 | struct ipc_log_context *ctxt; |
| 489 | struct ipc_log_page *pg = NULL; |
| 490 | int page_cnt, local_log_id; |
| 491 | unsigned long flags; |
| 492 | |
| 493 | ctxt = kzalloc(sizeof(struct ipc_log_context), GFP_KERNEL); |
| 494 | if (!ctxt) { |
| 495 | pr_err("%s: cannot create ipc_log_context\n", __func__); |
| 496 | return 0; |
| 497 | } |
| 498 | |
| 499 | local_log_id = atomic_add_return(1, &next_log_id); |
| 500 | init_completion(&ctxt->read_avail); |
| 501 | INIT_LIST_HEAD(&ctxt->page_list); |
| 502 | INIT_LIST_HEAD(&ctxt->dfunc_info_list); |
| 503 | spin_lock_init(&ctxt->ipc_log_context_lock); |
| 504 | for (page_cnt = 0; page_cnt < max_num_pages; page_cnt++) { |
| 505 | pg = kzalloc(sizeof(struct ipc_log_page), GFP_KERNEL); |
| 506 | if (!pg) { |
| 507 | pr_err("%s: cannot create ipc_log_page\n", __func__); |
| 508 | goto release_ipc_log_context; |
| 509 | } |
| 510 | pg->hdr.magic = IPC_LOGGING_MAGIC_NUM; |
| 511 | pg->hdr.nmagic = ~(IPC_LOGGING_MAGIC_NUM); |
| 512 | pg->hdr.log_id = (uint32_t)local_log_id; |
| 513 | pg->hdr.page_num = page_cnt; |
| 514 | pg->hdr.read_offset = 0xFFFF; |
| 515 | pg->hdr.write_offset = 0xFFFF; |
| 516 | spin_lock_irqsave(&ctxt->ipc_log_context_lock, flags); |
| 517 | list_add_tail(&pg->hdr.list, &ctxt->page_list); |
| 518 | spin_unlock_irqrestore(&ctxt->ipc_log_context_lock, flags); |
| 519 | } |
| 520 | ctxt->first_page = get_first_page(ctxt); |
| 521 | ctxt->last_page = pg; |
| 522 | ctxt->write_page = ctxt->first_page; |
| 523 | ctxt->read_page = ctxt->first_page; |
| 524 | ctxt->write_page->hdr.write_offset = 0; |
| 525 | ctxt->read_page->hdr.read_offset = 0; |
| 526 | ctxt->write_avail = max_num_pages * (PAGE_SIZE - |
| 527 | sizeof(struct ipc_log_page_header)); |
| 528 | |
| 529 | create_ctx_debugfs(ctxt, mod_name); |
| 530 | |
| 531 | spin_lock_irqsave(&ipc_log_context_list_lock, flags); |
| 532 | list_add_tail(&ctxt->list, &ipc_log_context_list); |
| 533 | spin_unlock_irqrestore(&ipc_log_context_list_lock, flags); |
| 534 | return (void *)ctxt; |
| 535 | |
| 536 | release_ipc_log_context: |
| 537 | while (page_cnt-- > 0) { |
| 538 | pg = get_first_page(ctxt); |
| 539 | list_del(&pg->hdr.list); |
| 540 | kfree(pg); |
| 541 | } |
| 542 | kfree(ctxt); |
| 543 | return 0; |
| 544 | } |
| 545 | EXPORT_SYMBOL(ipc_log_context_create); |
| 546 | |
| 547 | static int __init ipc_logging_init(void) |
| 548 | { |
| 549 | check_and_create_debugfs(); |
| 550 | return 0; |
| 551 | } |
| 552 | |
| 553 | module_init(ipc_logging_init); |
| 554 | |
| 555 | MODULE_DESCRIPTION("ipc logging"); |
| 556 | MODULE_LICENSE("GPL v2"); |