tools/power/acpi/tools/acpidbg/acpidbg.c

   1 /*
   2  * ACPI AML interfacing userspace utility
   3  *
   4  * Copyright (C) 2015, Intel Corporation
   5  * Authors: Lv Zheng <lv.zheng@intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <acpi/acpi.h>
  13
  14 /* Headers not included by include/acpi/platform/aclinux.h */
  15 #include <stdbool.h>
  16 #include <fcntl.h>
  17 #include <assert.h>
  18 #include <linux/circ_buf.h>
  19
  20 #define ACPI_AML_FILE           "/sys/kernel/debug/acpi/acpidbg"
  21 #define ACPI_AML_SEC_TICK       1
  22 #define ACPI_AML_USEC_PEEK      200
  23 #define ACPI_AML_BUF_SIZE       4096
  24
  25 #define ACPI_AML_BATCH_WRITE_CMD        0x00 /* Write command to kernel */
  26 #define ACPI_AML_BATCH_READ_LOG         0x01 /* Read log from kernel */
  27 #define ACPI_AML_BATCH_WRITE_LOG        0x02 /* Write log to console */
  28
  29 #define ACPI_AML_LOG_START              0x00
  30 #define ACPI_AML_PROMPT_START           0x01
  31 #define ACPI_AML_PROMPT_STOP            0x02
  32 #define ACPI_AML_LOG_STOP               0x03
  33 #define ACPI_AML_PROMPT_ROLL            0x04
  34
  35 #define ACPI_AML_INTERACTIVE    0x00
  36 #define ACPI_AML_BATCH          0x01
  37
  38 #define circ_count(circ) \
  39         (CIRC_CNT((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
  40 #define circ_count_to_end(circ) \
  41         (CIRC_CNT_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
  42 #define circ_space(circ) \
  43         (CIRC_SPACE((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
  44 #define circ_space_to_end(circ) \
  45         (CIRC_SPACE_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
  46
  47 #define acpi_aml_cmd_count()    circ_count(&acpi_aml_cmd_crc)
  48 #define acpi_aml_log_count()    circ_count(&acpi_aml_log_crc)
  49 #define acpi_aml_cmd_space()    circ_space(&acpi_aml_cmd_crc)
  50 #define acpi_aml_log_space()    circ_space(&acpi_aml_log_crc)
  51
  52 #define ACPI_AML_DO(_fd, _op, _buf, _ret)                               \
  53         do {                                                            \
  54                 _ret = acpi_aml_##_op(_fd, &acpi_aml_##_buf##_crc);     \
  55                 if (_ret == 0) {                                        \
  56                         fprintf(stderr,                                 \
  57                                 "%s %s pipe closed.\n", #_buf, #_op);   \
  58                         return;                                         \
  59                 }                                                       \
  60         } while (0)
  61 #define ACPI_AML_BATCH_DO(_fd, _op, _buf, _ret)                         \
  62         do {                                                            \
  63                 _ret = acpi_aml_##_op##_batch_##_buf(_fd,               \
  64                          &acpi_aml_##_buf##_crc);                       \
  65                 if (_ret == 0)                                          \
  66                         return;                                         \
  67         } while (0)
  68
  69
  70 static char acpi_aml_cmd_buf[ACPI_AML_BUF_SIZE];
  71 static char acpi_aml_log_buf[ACPI_AML_BUF_SIZE];
  72 static struct circ_buf acpi_aml_cmd_crc = {
  73         .buf = acpi_aml_cmd_buf,
  74         .head = 0,
  75         .tail = 0,
  76 };
  77 static struct circ_buf acpi_aml_log_crc = {
  78         .buf = acpi_aml_log_buf,
  79         .head = 0,
  80         .tail = 0,
  81 };
  82 static const char *acpi_aml_file_path = ACPI_AML_FILE;
  83 static unsigned long acpi_aml_mode = ACPI_AML_INTERACTIVE;
  84 static bool acpi_aml_exit;
  85
  86 static bool acpi_aml_batch_drain;
  87 static unsigned long acpi_aml_batch_state;
  88 static char acpi_aml_batch_prompt;
  89 static char acpi_aml_batch_roll;
  90 static unsigned long acpi_aml_log_state;
  91 static char *acpi_aml_batch_cmd = NULL;
  92 static char *acpi_aml_batch_pos = NULL;
  93
  94 static int acpi_aml_set_fl(int fd, int flags)
  95 {
  96         int ret;
  97
  98         ret = fcntl(fd, F_GETFL, 0);
  99         if (ret < 0) {
 100                 perror("fcntl(F_GETFL)");
 101                 return ret;
 102         }
 103         flags |= ret;
 104         ret = fcntl(fd, F_SETFL, flags);
 105         if (ret < 0) {
 106                 perror("fcntl(F_SETFL)");
 107                 return ret;
 108         }
 109         return ret;
 110 }
 111
 112 static int acpi_aml_set_fd(int fd, int maxfd, fd_set *set)
 113 {
 114         if (fd > maxfd)
 115                 maxfd = fd;
 116         FD_SET(fd, set);
 117         return maxfd;
 118 }
 119
 120 static int acpi_aml_read(int fd, struct circ_buf *crc)
 121 {
 122         char *p;
 123         int len;
 124
 125         p = &crc->buf[crc->head];
 126         len = circ_space_to_end(crc);
 127         len = read(fd, p, len);
 128         if (len < 0)
 129                 perror("read");
 130         else if (len > 0)
 131                 crc->head = (crc->head + len) & (ACPI_AML_BUF_SIZE - 1);
 132         return len;
 133 }
 134
 135 static int acpi_aml_read_batch_cmd(int unused, struct circ_buf *crc)
 136 {
 137         char *p;
 138         int len;
 139         int remained = strlen(acpi_aml_batch_pos);
 140
 141         p = &crc->buf[crc->head];
 142         len = circ_space_to_end(crc);
 143         if (len > remained) {
 144                 memcpy(p, acpi_aml_batch_pos, remained);
 145                 acpi_aml_batch_pos += remained;
 146                 len = remained;
 147         } else {
 148                 memcpy(p, acpi_aml_batch_pos, len);
 149                 acpi_aml_batch_pos += len;
 150         }
 151         if (len > 0)
 152                 crc->head = (crc->head + len) & (ACPI_AML_BUF_SIZE - 1);
 153         return len;
 154 }
 155
 156 static int acpi_aml_read_batch_log(int fd, struct circ_buf *crc)
 157 {
 158         char *p;
 159         int len;
 160         int ret = 0;
 161
 162         p = &crc->buf[crc->head];
 163         len = circ_space_to_end(crc);
 164         while (ret < len && acpi_aml_log_state != ACPI_AML_LOG_STOP) {
 165                 if (acpi_aml_log_state == ACPI_AML_PROMPT_ROLL) {
 166                         *p = acpi_aml_batch_roll;
 167                         len = 1;
 168                         crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
 169                         ret += 1;
 170                         acpi_aml_log_state = ACPI_AML_LOG_START;
 171                 } else {
 172                         len = read(fd, p, 1);
 173                         if (len <= 0) {
 174                                 if (len < 0)
 175                                         perror("read");
 176                                 ret = len;
 177                                 break;
 178                         }
 179                 }
 180                 switch (acpi_aml_log_state) {
 181                 case ACPI_AML_LOG_START:
 182                         if (*p == '\n')
 183                                 acpi_aml_log_state = ACPI_AML_PROMPT_START;
 184                         crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
 185                         ret += 1;
 186                         break;
 187                 case ACPI_AML_PROMPT_START:
 188                         if (*p == ACPI_DEBUGGER_COMMAND_PROMPT ||
 189                             *p == ACPI_DEBUGGER_EXECUTE_PROMPT) {
 190                                 acpi_aml_batch_prompt = *p;
 191                                 acpi_aml_log_state = ACPI_AML_PROMPT_STOP;
 192                         } else {
 193                                 if (*p != '\n')
 194                                         acpi_aml_log_state = ACPI_AML_LOG_START;
 195                                 crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
 196                                 ret += 1;
 197                         }
 198                         break;
 199                 case ACPI_AML_PROMPT_STOP:
 200                         if (*p == ' ') {
 201                                 acpi_aml_log_state = ACPI_AML_LOG_STOP;
 202                                 acpi_aml_exit = true;
 203                         } else {
 204                                 /* Roll back */
 205                                 acpi_aml_log_state = ACPI_AML_PROMPT_ROLL;
 206                                 acpi_aml_batch_roll = *p;
 207                                 *p = acpi_aml_batch_prompt;
 208                                 crc->head = (crc->head + 1) & (ACPI_AML_BUF_SIZE - 1);
 209                                 ret += 1;
 210                         }
 211                         break;
 212                 default:
 213                         assert(0);
 214                         break;
 215                 }
 216         }
 217         return ret;
 218 }
 219
 220 static int acpi_aml_write(int fd, struct circ_buf *crc)
 221 {
 222         char *p;
 223         int len;
 224
 225         p = &crc->buf[crc->tail];
 226         len = circ_count_to_end(crc);
 227         len = write(fd, p, len);
 228         if (len < 0)
 229                 perror("write");
 230         else if (len > 0)
 231                 crc->tail = (crc->tail + len) & (ACPI_AML_BUF_SIZE - 1);
 232         return len;
 233 }
 234
 235 static int acpi_aml_write_batch_log(int fd, struct circ_buf *crc)
 236 {
 237         char *p;
 238         int len;
 239
 240         p = &crc->buf[crc->tail];
 241         len = circ_count_to_end(crc);
 242         if (!acpi_aml_batch_drain) {
 243                 len = write(fd, p, len);
 244                 if (len < 0)
 245                         perror("write");
 246         }
 247         if (len > 0)
 248                 crc->tail = (crc->tail + len) & (ACPI_AML_BUF_SIZE - 1);
 249         return len;
 250 }
 251
 252 static int acpi_aml_write_batch_cmd(int fd, struct circ_buf *crc)
 253 {
 254         int len;
 255
 256         len = acpi_aml_write(fd, crc);
 257         if (circ_count_to_end(crc) == 0)
 258                 acpi_aml_batch_state = ACPI_AML_BATCH_READ_LOG;
 259         return len;
 260 }
 261
 262 static void acpi_aml_loop(int fd)
 263 {
 264         fd_set rfds;
 265         fd_set wfds;
 266         struct timeval tv;
 267         int ret;
 268         int maxfd = 0;
 269
 270         if (acpi_aml_mode == ACPI_AML_BATCH) {
 271                 acpi_aml_log_state = ACPI_AML_LOG_START;
 272                 acpi_aml_batch_pos = acpi_aml_batch_cmd;
 273                 if (acpi_aml_batch_drain)
 274                         acpi_aml_batch_state = ACPI_AML_BATCH_READ_LOG;
 275                 else
 276                         acpi_aml_batch_state = ACPI_AML_BATCH_WRITE_CMD;
 277         }
 278         acpi_aml_exit = false;
 279         while (!acpi_aml_exit) {
 280                 tv.tv_sec = ACPI_AML_SEC_TICK;
 281                 tv.tv_usec = 0;
 282                 FD_ZERO(&rfds);
 283                 FD_ZERO(&wfds);
 284
 285                 if (acpi_aml_cmd_space()) {
 286                         if (acpi_aml_mode == ACPI_AML_INTERACTIVE)
 287                                 maxfd = acpi_aml_set_fd(STDIN_FILENO, maxfd, &rfds);
 288                         else if (strlen(acpi_aml_batch_pos) &&
 289                                  acpi_aml_batch_state == ACPI_AML_BATCH_WRITE_CMD)
 290                                 ACPI_AML_BATCH_DO(STDIN_FILENO, read, cmd, ret);
 291                 }
 292                 if (acpi_aml_cmd_count() &&
 293                     (acpi_aml_mode == ACPI_AML_INTERACTIVE ||
 294                      acpi_aml_batch_state == ACPI_AML_BATCH_WRITE_CMD))
 295                         maxfd = acpi_aml_set_fd(fd, maxfd, &wfds);
 296                 if (acpi_aml_log_space() &&
 297                     (acpi_aml_mode == ACPI_AML_INTERACTIVE ||
 298                      acpi_aml_batch_state == ACPI_AML_BATCH_READ_LOG))
 299                         maxfd = acpi_aml_set_fd(fd, maxfd, &rfds);
 300                 if (acpi_aml_log_count())
 301                         maxfd = acpi_aml_set_fd(STDOUT_FILENO, maxfd, &wfds);
 302
 303                 ret = select(maxfd+1, &rfds, &wfds, NULL, &tv);
 304                 if (ret < 0) {
 305                         perror("select");
 306                         break;
 307                 }
 308                 if (ret > 0) {
 309                         if (FD_ISSET(STDIN_FILENO, &rfds))
 310                                 ACPI_AML_DO(STDIN_FILENO, read, cmd, ret);
 311                         if (FD_ISSET(fd, &wfds)) {
 312                                 if (acpi_aml_mode == ACPI_AML_BATCH)
 313                                         ACPI_AML_BATCH_DO(fd, write, cmd, ret);
 314                                 else
 315                                         ACPI_AML_DO(fd, write, cmd, ret);
 316                         }
 317                         if (FD_ISSET(fd, &rfds)) {
 318                                 if (acpi_aml_mode == ACPI_AML_BATCH)
 319                                         ACPI_AML_BATCH_DO(fd, read, log, ret);
 320                                 else
 321                                         ACPI_AML_DO(fd, read, log, ret);
 322                         }
 323                         if (FD_ISSET(STDOUT_FILENO, &wfds)) {
 324                                 if (acpi_aml_mode == ACPI_AML_BATCH)
 325                                         ACPI_AML_BATCH_DO(STDOUT_FILENO, write, log, ret);
 326                                 else
 327                                         ACPI_AML_DO(STDOUT_FILENO, write, log, ret);
 328                         }
 329                 }
 330         }
 331 }
 332
 333 static bool acpi_aml_readable(int fd)
 334 {
 335         fd_set rfds;
 336         struct timeval tv;
 337         int ret;
 338         int maxfd = 0;
 339
 340         tv.tv_sec = 0;
 341         tv.tv_usec = ACPI_AML_USEC_PEEK;
 342         FD_ZERO(&rfds);
 343         maxfd = acpi_aml_set_fd(fd, maxfd, &rfds);
 344         ret = select(maxfd+1, &rfds, NULL, NULL, &tv);
 345         if (ret < 0)
 346                 perror("select");
 347         if (ret > 0 && FD_ISSET(fd, &rfds))
 348                 return true;
 349         return false;
 350 }
 351
 352 /*
 353  * This is a userspace IO flush implementation, replying on the prompt
 354  * characters and can be turned into a flush() call after kernel implements
 355  * .flush() filesystem operation.
 356  */
 357 static void acpi_aml_flush(int fd)
 358 {
 359         while (acpi_aml_readable(fd)) {
 360                 acpi_aml_batch_drain = true;
 361                 acpi_aml_loop(fd);
 362                 acpi_aml_batch_drain = false;
 363         }
 364 }
 365
 366 void usage(FILE *file, char *progname)
 367 {
 368         fprintf(file, "usage: %s [-b cmd] [-f file] [-h]\n", progname);
 369         fprintf(file, "\nOptions:\n");
 370         fprintf(file, "  -b     Specify command to be executed in batch mode\n");
 371         fprintf(file, "  -f     Specify interface file other than");
 372         fprintf(file, "         /sys/kernel/debug/acpi/acpidbg\n");
 373         fprintf(file, "  -h     Print this help message\n");
 374 }
 375
 376 int main(int argc, char **argv)
 377 {
 378         int fd = 0;
 379         int ch;
 380         int len;
 381         int ret = EXIT_SUCCESS;
 382
 383         while ((ch = getopt(argc, argv, "b:f:h")) != -1) {
 384                 switch (ch) {
 385                 case 'b':
 386                         if (acpi_aml_batch_cmd) {
 387                                 fprintf(stderr, "Already specify %s\n",
 388                                         acpi_aml_batch_cmd);
 389                                 ret = EXIT_FAILURE;
 390                                 goto exit;
 391                         }
 392                         len = strlen(optarg);
 393                         acpi_aml_batch_cmd = calloc(len + 2, 1);
 394                         if (!acpi_aml_batch_cmd) {
 395                                 perror("calloc");
 396                                 ret = EXIT_FAILURE;
 397                                 goto exit;
 398                         }
 399                         memcpy(acpi_aml_batch_cmd, optarg, len);
 400                         acpi_aml_batch_cmd[len] = '\n';
 401                         acpi_aml_mode = ACPI_AML_BATCH;
 402                         break;
 403                 case 'f':
 404                         acpi_aml_file_path = optarg;
 405                         break;
 406                 case 'h':
 407                         usage(stdout, argv[0]);
 408                         goto exit;
 409                         break;
 410                 case '?':
 411                 default:
 412                         usage(stderr, argv[0]);
 413                         ret = EXIT_FAILURE;
 414                         goto exit;
 415                         break;
 416                 }
 417         }
 418
 419         fd = open(acpi_aml_file_path, O_RDWR | O_NONBLOCK);
 420         if (fd < 0) {
 421                 perror("open");
 422                 ret = EXIT_FAILURE;
 423                 goto exit;
 424         }
 425         acpi_aml_set_fl(STDIN_FILENO, O_NONBLOCK);
 426         acpi_aml_set_fl(STDOUT_FILENO, O_NONBLOCK);
 427
 428         if (acpi_aml_mode == ACPI_AML_BATCH)
 429                 acpi_aml_flush(fd);
 430         acpi_aml_loop(fd);
 431
 432 exit:
 433         if (fd < 0)
 434                 close(fd);
 435         if (acpi_aml_batch_cmd)
 436                 free(acpi_aml_batch_cmd);
 437         return ret;
 438 }