arch/um/drivers/chan_kern.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <linux/stddef.h>
   7 #include <linux/kernel.h>
   8 #include <linux/list.h>
   9 #include <linux/slab.h>
  10 #include <linux/tty.h>
  11 #include <linux/string.h>
  12 #include <linux/tty_flip.h>
  13 #include <asm/irq.h>
  14 #include "chan_kern.h"
  15 #include "kern.h"
  16 #include "irq_user.h"
  17 #include "sigio.h"
  18 #include "line.h"
  19 #include "os.h"
  20
  21 #ifdef CONFIG_NOCONFIG_CHAN
  22 static void *not_configged_init(char *str, int device,
  23                                 const struct chan_opts *opts)
  24 {
  25         printk("Using a channel type which is configured out of "
  26                "UML\n");
  27         return NULL;
  28 }
  29
  30 static int not_configged_open(int input, int output, int primary, void *data,
  31                               char **dev_out)
  32 {
  33         printk("Using a channel type which is configured out of "
  34                "UML\n");
  35         return -ENODEV;
  36 }
  37
  38 static void not_configged_close(int fd, void *data)
  39 {
  40         printk("Using a channel type which is configured out of "
  41                "UML\n");
  42 }
  43
  44 static int not_configged_read(int fd, char *c_out, void *data)
  45 {
  46         printk("Using a channel type which is configured out of "
  47                "UML\n");
  48         return -EIO;
  49 }
  50
  51 static int not_configged_write(int fd, const char *buf, int len, void *data)
  52 {
  53         printk("Using a channel type which is configured out of "
  54                "UML\n");
  55         return -EIO;
  56 }
  57
  58 static int not_configged_console_write(int fd, const char *buf, int len)
  59 {
  60         printk("Using a channel type which is configured out of "
  61                "UML\n");
  62         return -EIO;
  63 }
  64
  65 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
  66                                      unsigned short *cols)
  67 {
  68         printk("Using a channel type which is configured out of "
  69                "UML\n");
  70         return -ENODEV;
  71 }
  72
  73 static void not_configged_free(void *data)
  74 {
  75         printk("Using a channel type which is configured out of "
  76                "UML\n");
  77 }
  78
  79 static const struct chan_ops not_configged_ops = {
  80         .init           = not_configged_init,
  81         .open           = not_configged_open,
  82         .close          = not_configged_close,
  83         .read           = not_configged_read,
  84         .write          = not_configged_write,
  85         .console_write  = not_configged_console_write,
  86         .window_size    = not_configged_window_size,
  87         .free           = not_configged_free,
  88         .winch          = 0,
  89 };
  90 #endif /* CONFIG_NOCONFIG_CHAN */
  91
  92 void generic_close(int fd, void *unused)
  93 {
  94         os_close_file(fd);
  95 }
  96
  97 int generic_read(int fd, char *c_out, void *unused)
  98 {
  99         int n;
 100
 101         n = os_read_file(fd, c_out, sizeof(*c_out));
 102
 103         if(n == -EAGAIN)
 104                 return 0;
 105         else if(n == 0)
 106                 return -EIO;
 107         return n;
 108 }
 109
 110 /* XXX Trivial wrapper around os_write_file */
 111
 112 int generic_write(int fd, const char *buf, int n, void *unused)
 113 {
 114         return os_write_file(fd, buf, n);
 115 }
 116
 117 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 118                         unsigned short *cols_out)
 119 {
 120         int rows, cols;
 121         int ret;
 122
 123         ret = os_window_size(fd, &rows, &cols);
 124         if(ret < 0)
 125                 return ret;
 126
 127         ret = ((*rows_out != rows) || (*cols_out != cols));
 128
 129         *rows_out = rows;
 130         *cols_out = cols;
 131
 132         return ret;
 133 }
 134
 135 void generic_free(void *data)
 136 {
 137         kfree(data);
 138 }
 139
 140 static void tty_receive_char(struct tty_struct *tty, char ch)
 141 {
 142         if(tty == NULL) return;
 143
 144         if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
 145                 if(ch == STOP_CHAR(tty)){
 146                         stop_tty(tty);
 147                         return;
 148                 }
 149                 else if(ch == START_CHAR(tty)){
 150                         start_tty(tty);
 151                         return;
 152                 }
 153         }
 154
 155         tty_insert_flip_char(tty, ch, TTY_NORMAL);
 156 }
 157
 158 static int open_one_chan(struct chan *chan)
 159 {
 160         int fd;
 161
 162         if(chan->opened)
 163                 return 0;
 164
 165         if(chan->ops->open == NULL)
 166                 fd = 0;
 167         else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
 168                                      chan->data, &chan->dev);
 169         if(fd < 0)
 170                 return fd;
 171         chan->fd = fd;
 172
 173         chan->opened = 1;
 174         return 0;
 175 }
 176
 177 int open_chan(struct list_head *chans)
 178 {
 179         struct list_head *ele;
 180         struct chan *chan;
 181         int ret, err = 0;
 182
 183         list_for_each(ele, chans){
 184                 chan = list_entry(ele, struct chan, list);
 185                 ret = open_one_chan(chan);
 186                 if(chan->primary)
 187                         err = ret;
 188         }
 189         return err;
 190 }
 191
 192 void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
 193 {
 194         struct list_head *ele;
 195         struct chan *chan;
 196
 197         list_for_each(ele, chans){
 198                 chan = list_entry(ele, struct chan, list);
 199                 if(chan->primary && chan->output && chan->ops->winch){
 200                         register_winch(chan->fd, tty);
 201                         return;
 202                 }
 203         }
 204 }
 205
 206 int enable_chan(struct line *line)
 207 {
 208         struct list_head *ele;
 209         struct chan *chan;
 210         int err;
 211
 212         list_for_each(ele, &line->chan_list){
 213                 chan = list_entry(ele, struct chan, list);
 214                 err = open_one_chan(chan);
 215                 if (err) {
 216                         if (chan->primary)
 217                                 goto out_close;
 218
 219                         continue;
 220                 }
 221
 222                 if(chan->enabled)
 223                         continue;
 224                 err = line_setup_irq(chan->fd, chan->input, chan->output, line,
 225                                      chan);
 226                 if (err)
 227                         goto out_close;
 228
 229                 chan->enabled = 1;
 230         }
 231
 232         return 0;
 233
 234  out_close:
 235         close_chan(&line->chan_list, 0);
 236         return err;
 237 }
 238
 239 /* Items are added in IRQ context, when free_irq can't be called, and
 240  * removed in process context, when it can.
 241  * This handles interrupt sources which disappear, and which need to
 242  * be permanently disabled.  This is discovered in IRQ context, but
 243  * the freeing of the IRQ must be done later.
 244  */
 245 static DEFINE_SPINLOCK(irqs_to_free_lock);
 246 static LIST_HEAD(irqs_to_free);
 247
 248 void free_irqs(void)
 249 {
 250         struct chan *chan;
 251         LIST_HEAD(list);
 252         struct list_head *ele;
 253         unsigned long flags;
 254
 255         spin_lock_irqsave(&irqs_to_free_lock, flags);
 256         list_splice_init(&irqs_to_free, &list);
 257         spin_unlock_irqrestore(&irqs_to_free_lock, flags);
 258
 259         list_for_each(ele, &list){
 260                 chan = list_entry(ele, struct chan, free_list);
 261
 262                 if(chan->input)
 263                         free_irq(chan->line->driver->read_irq, chan);
 264                 if(chan->output)
 265                         free_irq(chan->line->driver->write_irq, chan);
 266                 chan->enabled = 0;
 267         }
 268 }
 269
 270 static void close_one_chan(struct chan *chan, int delay_free_irq)
 271 {
 272         unsigned long flags;
 273
 274         if(!chan->opened)
 275                 return;
 276
 277         if(delay_free_irq){
 278                 spin_lock_irqsave(&irqs_to_free_lock, flags);
 279                 list_add(&chan->free_list, &irqs_to_free);
 280                 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
 281         }
 282         else {
 283                 if(chan->input)
 284                         free_irq(chan->line->driver->read_irq, chan);
 285                 if(chan->output)
 286                         free_irq(chan->line->driver->write_irq, chan);
 287                 chan->enabled = 0;
 288         }
 289         if(chan->ops->close != NULL)
 290                 (*chan->ops->close)(chan->fd, chan->data);
 291
 292         chan->opened = 0;
 293         chan->fd = -1;
 294 }
 295
 296 void close_chan(struct list_head *chans, int delay_free_irq)
 297 {
 298         struct chan *chan;
 299
 300         /* Close in reverse order as open in case more than one of them
 301          * refers to the same device and they save and restore that device's
 302          * state.  Then, the first one opened will have the original state,
 303          * so it must be the last closed.
 304          */
 305         list_for_each_entry_reverse(chan, chans, list) {
 306                 close_one_chan(chan, delay_free_irq);
 307         }
 308 }
 309
 310 void deactivate_chan(struct list_head *chans, int irq)
 311 {
 312         struct list_head *ele;
 313
 314         struct chan *chan;
 315         list_for_each(ele, chans) {
 316                 chan = list_entry(ele, struct chan, list);
 317
 318                 if(chan->enabled && chan->input)
 319                         deactivate_fd(chan->fd, irq);
 320         }
 321 }
 322
 323 void reactivate_chan(struct list_head *chans, int irq)
 324 {
 325         struct list_head *ele;
 326         struct chan *chan;
 327
 328         list_for_each(ele, chans) {
 329                 chan = list_entry(ele, struct chan, list);
 330
 331                 if(chan->enabled && chan->input)
 332                         reactivate_fd(chan->fd, irq);
 333         }
 334 }
 335
 336 int write_chan(struct list_head *chans, const char *buf, int len,
 337                int write_irq)
 338 {
 339         struct list_head *ele;
 340         struct chan *chan = NULL;
 341         int n, ret = 0;
 342
 343         list_for_each(ele, chans) {
 344                 chan = list_entry(ele, struct chan, list);
 345                 if (!chan->output || (chan->ops->write == NULL))
 346                         continue;
 347                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 348                 if (chan->primary) {
 349                         ret = n;
 350                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 351                                 reactivate_fd(chan->fd, write_irq);
 352                 }
 353         }
 354         return ret;
 355 }
 356
 357 int console_write_chan(struct list_head *chans, const char *buf, int len)
 358 {
 359         struct list_head *ele;
 360         struct chan *chan;
 361         int n, ret = 0;
 362
 363         list_for_each(ele, chans){
 364                 chan = list_entry(ele, struct chan, list);
 365                 if(!chan->output || (chan->ops->console_write == NULL))
 366                         continue;
 367                 n = chan->ops->console_write(chan->fd, buf, len);
 368                 if(chan->primary) ret = n;
 369         }
 370         return ret;
 371 }
 372
 373 int console_open_chan(struct line *line, struct console *co)
 374 {
 375         int err;
 376
 377         err = open_chan(&line->chan_list);
 378         if(err)
 379                 return err;
 380
 381         printk("Console initialized on /dev/%s%d\n", co->name, co->index);
 382         return 0;
 383 }
 384
 385 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 386                       unsigned short *cols_out)
 387 {
 388         struct list_head *ele;
 389         struct chan *chan;
 390
 391         list_for_each(ele, chans){
 392                 chan = list_entry(ele, struct chan, list);
 393                 if(chan->primary){
 394                         if(chan->ops->window_size == NULL)
 395                                 return 0;
 396                         return chan->ops->window_size(chan->fd, chan->data,
 397                                                       rows_out, cols_out);
 398                 }
 399         }
 400         return 0;
 401 }
 402
 403 static void free_one_chan(struct chan *chan, int delay_free_irq)
 404 {
 405         list_del(&chan->list);
 406
 407         close_one_chan(chan, delay_free_irq);
 408
 409         if(chan->ops->free != NULL)
 410                 (*chan->ops->free)(chan->data);
 411
 412         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 413         kfree(chan);
 414 }
 415
 416 static void free_chan(struct list_head *chans, int delay_free_irq)
 417 {
 418         struct list_head *ele, *next;
 419         struct chan *chan;
 420
 421         list_for_each_safe(ele, next, chans){
 422                 chan = list_entry(ele, struct chan, list);
 423                 free_one_chan(chan, delay_free_irq);
 424         }
 425 }
 426
 427 static int one_chan_config_string(struct chan *chan, char *str, int size,
 428                                   char **error_out)
 429 {
 430         int n = 0;
 431
 432         if(chan == NULL){
 433                 CONFIG_CHUNK(str, size, n, "none", 1);
 434                 return n;
 435         }
 436
 437         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 438
 439         if(chan->dev == NULL){
 440                 CONFIG_CHUNK(str, size, n, "", 1);
 441                 return n;
 442         }
 443
 444         CONFIG_CHUNK(str, size, n, ":", 0);
 445         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 446
 447         return n;
 448 }
 449
 450 static int chan_pair_config_string(struct chan *in, struct chan *out,
 451                                    char *str, int size, char **error_out)
 452 {
 453         int n;
 454
 455         n = one_chan_config_string(in, str, size, error_out);
 456         str += n;
 457         size -= n;
 458
 459         if(in == out){
 460                 CONFIG_CHUNK(str, size, n, "", 1);
 461                 return n;
 462         }
 463
 464         CONFIG_CHUNK(str, size, n, ",", 1);
 465         n = one_chan_config_string(out, str, size, error_out);
 466         str += n;
 467         size -= n;
 468         CONFIG_CHUNK(str, size, n, "", 1);
 469
 470         return n;
 471 }
 472
 473 int chan_config_string(struct list_head *chans, char *str, int size,
 474                        char **error_out)
 475 {
 476         struct list_head *ele;
 477         struct chan *chan, *in = NULL, *out = NULL;
 478
 479         list_for_each(ele, chans){
 480                 chan = list_entry(ele, struct chan, list);
 481                 if(!chan->primary)
 482                         continue;
 483                 if(chan->input)
 484                         in = chan;
 485                 if(chan->output)
 486                         out = chan;
 487         }
 488
 489         return chan_pair_config_string(in, out, str, size, error_out);
 490 }
 491
 492 struct chan_type {
 493         char *key;
 494         const struct chan_ops *ops;
 495 };
 496
 497 static const struct chan_type chan_table[] = {
 498         { "fd", &fd_ops },
 499
 500 #ifdef CONFIG_NULL_CHAN
 501         { "null", &null_ops },
 502 #else
 503         { "null", &not_configged_ops },
 504 #endif
 505
 506 #ifdef CONFIG_PORT_CHAN
 507         { "port", &port_ops },
 508 #else
 509         { "port", &not_configged_ops },
 510 #endif
 511
 512 #ifdef CONFIG_PTY_CHAN
 513         { "pty", &pty_ops },
 514         { "pts", &pts_ops },
 515 #else
 516         { "pty", &not_configged_ops },
 517         { "pts", &not_configged_ops },
 518 #endif
 519
 520 #ifdef CONFIG_TTY_CHAN
 521         { "tty", &tty_ops },
 522 #else
 523         { "tty", &not_configged_ops },
 524 #endif
 525
 526 #ifdef CONFIG_XTERM_CHAN
 527         { "xterm", &xterm_ops },
 528 #else
 529         { "xterm", &not_configged_ops },
 530 #endif
 531 };
 532
 533 static struct chan *parse_chan(struct line *line, char *str, int device,
 534                                const struct chan_opts *opts, char **error_out)
 535 {
 536         const struct chan_type *entry;
 537         const struct chan_ops *ops;
 538         struct chan *chan;
 539         void *data;
 540         int i;
 541
 542         ops = NULL;
 543         data = NULL;
 544         for(i = 0; i < ARRAY_SIZE(chan_table); i++){
 545                 entry = &chan_table[i];
 546                 if(!strncmp(str, entry->key, strlen(entry->key))){
 547                         ops = entry->ops;
 548                         str += strlen(entry->key);
 549                         break;
 550                 }
 551         }
 552         if(ops == NULL){
 553                 *error_out = "No match for configured backends";
 554                 return NULL;
 555         }
 556
 557         data = (*ops->init)(str, device, opts);
 558         if(data == NULL){
 559                 *error_out = "Configuration failed";
 560                 return NULL;
 561         }
 562
 563         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 564         if(chan == NULL){
 565                 *error_out = "Memory allocation failed";
 566                 return NULL;
 567         }
 568         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 569                                  .free_list     =
 570                                         LIST_HEAD_INIT(chan->free_list),
 571                                  .line          = line,
 572                                  .primary       = 1,
 573                                  .input         = 0,
 574                                  .output        = 0,
 575                                  .opened        = 0,
 576                                  .enabled       = 0,
 577                                  .fd            = -1,
 578                                  .ops           = ops,
 579                                  .data          = data });
 580         return chan;
 581 }
 582
 583 int parse_chan_pair(char *str, struct line *line, int device,
 584                     const struct chan_opts *opts, char **error_out)
 585 {
 586         struct list_head *chans = &line->chan_list;
 587         struct chan *new, *chan;
 588         char *in, *out;
 589
 590         if(!list_empty(chans)){
 591                 chan = list_entry(chans->next, struct chan, list);
 592                 free_chan(chans, 0);
 593                 INIT_LIST_HEAD(chans);
 594         }
 595
 596         out = strchr(str, ',');
 597         if(out != NULL){
 598                 in = str;
 599                 *out = '\0';
 600                 out++;
 601                 new = parse_chan(line, in, device, opts, error_out);
 602                 if(new == NULL)
 603                         return -1;
 604
 605                 new->input = 1;
 606                 list_add(&new->list, chans);
 607
 608                 new = parse_chan(line, out, device, opts, error_out);
 609                 if(new == NULL)
 610                         return -1;
 611
 612                 list_add(&new->list, chans);
 613                 new->output = 1;
 614         }
 615         else {
 616                 new = parse_chan(line, str, device, opts, error_out);
 617                 if(new == NULL)
 618                         return -1;
 619
 620                 list_add(&new->list, chans);
 621                 new->input = 1;
 622                 new->output = 1;
 623         }
 624         return 0;
 625 }
 626
 627 int chan_out_fd(struct list_head *chans)
 628 {
 629         struct list_head *ele;
 630         struct chan *chan;
 631
 632         list_for_each(ele, chans){
 633                 chan = list_entry(ele, struct chan, list);
 634                 if(chan->primary && chan->output)
 635                         return chan->fd;
 636         }
 637         return -1;
 638 }
 639
 640 void chan_interrupt(struct list_head *chans, struct delayed_work *task,
 641                     struct tty_struct *tty, int irq)
 642 {
 643         struct list_head *ele, *next;
 644         struct chan *chan;
 645         int err;
 646         char c;
 647
 648         list_for_each_safe(ele, next, chans){
 649                 chan = list_entry(ele, struct chan, list);
 650                 if(!chan->input || (chan->ops->read == NULL)) continue;
 651                 do {
 652                         if (tty && !tty_buffer_request_room(tty, 1)) {
 653                                 schedule_delayed_work(task, 1);
 654                                 goto out;
 655                         }
 656                         err = chan->ops->read(chan->fd, &c, chan->data);
 657                         if(err > 0)
 658                                 tty_receive_char(tty, c);
 659                 } while(err > 0);
 660
 661                 if(err == 0) reactivate_fd(chan->fd, irq);
 662                 if(err == -EIO){
 663                         if(chan->primary){
 664                                 if(tty != NULL)
 665                                         tty_hangup(tty);
 666                                 close_chan(chans, 1);
 667                                 return;
 668                         }
 669                         else close_one_chan(chan, 1);
 670                 }
 671         }
 672  out:
 673         if(tty) tty_flip_buffer_push(tty);
 674 }