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 void enable_chan(struct line *line)
 207 {
 208         struct list_head *ele;
 209         struct chan *chan;
 210
 211         list_for_each(ele, &line->chan_list){
 212                 chan = list_entry(ele, struct chan, list);
 213                 if(open_one_chan(chan))
 214                         continue;
 215
 216                 if(chan->enabled)
 217                         continue;
 218                 line_setup_irq(chan->fd, chan->input, chan->output, line,
 219                                chan);
 220                 chan->enabled = 1;
 221         }
 222 }
 223
 224 /* Items are added in IRQ context, when free_irq can't be called, and
 225  * removed in process context, when it can.
 226  * This handles interrupt sources which disappear, and which need to
 227  * be permanently disabled.  This is discovered in IRQ context, but
 228  * the freeing of the IRQ must be done later.
 229  */
 230 static DEFINE_SPINLOCK(irqs_to_free_lock);
 231 static LIST_HEAD(irqs_to_free);
 232
 233 void free_irqs(void)
 234 {
 235         struct chan *chan;
 236         LIST_HEAD(list);
 237         struct list_head *ele;
 238         unsigned long flags;
 239
 240         spin_lock_irqsave(&irqs_to_free_lock, flags);
 241         list_splice_init(&irqs_to_free, &list);
 242         spin_unlock_irqrestore(&irqs_to_free_lock, flags);
 243
 244         list_for_each(ele, &list){
 245                 chan = list_entry(ele, struct chan, free_list);
 246
 247                 if(chan->input)
 248                         free_irq(chan->line->driver->read_irq, chan);
 249                 if(chan->output)
 250                         free_irq(chan->line->driver->write_irq, chan);
 251                 chan->enabled = 0;
 252         }
 253 }
 254
 255 static void close_one_chan(struct chan *chan, int delay_free_irq)
 256 {
 257         unsigned long flags;
 258
 259         if(!chan->opened)
 260                 return;
 261
 262         if(delay_free_irq){
 263                 spin_lock_irqsave(&irqs_to_free_lock, flags);
 264                 list_add(&chan->free_list, &irqs_to_free);
 265                 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
 266         }
 267         else {
 268                 if(chan->input)
 269                         free_irq(chan->line->driver->read_irq, chan);
 270                 if(chan->output)
 271                         free_irq(chan->line->driver->write_irq, chan);
 272                 chan->enabled = 0;
 273         }
 274         if(chan->ops->close != NULL)
 275                 (*chan->ops->close)(chan->fd, chan->data);
 276
 277         chan->opened = 0;
 278         chan->fd = -1;
 279 }
 280
 281 void close_chan(struct list_head *chans, int delay_free_irq)
 282 {
 283         struct chan *chan;
 284
 285         /* Close in reverse order as open in case more than one of them
 286          * refers to the same device and they save and restore that device's
 287          * state.  Then, the first one opened will have the original state,
 288          * so it must be the last closed.
 289          */
 290         list_for_each_entry_reverse(chan, chans, list) {
 291                 close_one_chan(chan, delay_free_irq);
 292         }
 293 }
 294
 295 void deactivate_chan(struct list_head *chans, int irq)
 296 {
 297         struct list_head *ele;
 298
 299         struct chan *chan;
 300         list_for_each(ele, chans) {
 301                 chan = list_entry(ele, struct chan, list);
 302
 303                 if(chan->enabled && chan->input)
 304                         deactivate_fd(chan->fd, irq);
 305         }
 306 }
 307
 308 void reactivate_chan(struct list_head *chans, int irq)
 309 {
 310         struct list_head *ele;
 311         struct chan *chan;
 312
 313         list_for_each(ele, chans) {
 314                 chan = list_entry(ele, struct chan, list);
 315
 316                 if(chan->enabled && chan->input)
 317                         reactivate_fd(chan->fd, irq);
 318         }
 319 }
 320
 321 int write_chan(struct list_head *chans, const char *buf, int len,
 322                int write_irq)
 323 {
 324         struct list_head *ele;
 325         struct chan *chan = NULL;
 326         int n, ret = 0;
 327
 328         list_for_each(ele, chans) {
 329                 chan = list_entry(ele, struct chan, list);
 330                 if (!chan->output || (chan->ops->write == NULL))
 331                         continue;
 332                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 333                 if (chan->primary) {
 334                         ret = n;
 335                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 336                                 reactivate_fd(chan->fd, write_irq);
 337                 }
 338         }
 339         return ret;
 340 }
 341
 342 int console_write_chan(struct list_head *chans, const char *buf, int len)
 343 {
 344         struct list_head *ele;
 345         struct chan *chan;
 346         int n, ret = 0;
 347
 348         list_for_each(ele, chans){
 349                 chan = list_entry(ele, struct chan, list);
 350                 if(!chan->output || (chan->ops->console_write == NULL))
 351                         continue;
 352                 n = chan->ops->console_write(chan->fd, buf, len);
 353                 if(chan->primary) ret = n;
 354         }
 355         return ret;
 356 }
 357
 358 int console_open_chan(struct line *line, struct console *co)
 359 {
 360         int err;
 361
 362         err = open_chan(&line->chan_list);
 363         if(err)
 364                 return err;
 365
 366         printk("Console initialized on /dev/%s%d\n", co->name, co->index);
 367         return 0;
 368 }
 369
 370 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 371                       unsigned short *cols_out)
 372 {
 373         struct list_head *ele;
 374         struct chan *chan;
 375
 376         list_for_each(ele, chans){
 377                 chan = list_entry(ele, struct chan, list);
 378                 if(chan->primary){
 379                         if(chan->ops->window_size == NULL)
 380                                 return 0;
 381                         return chan->ops->window_size(chan->fd, chan->data,
 382                                                       rows_out, cols_out);
 383                 }
 384         }
 385         return 0;
 386 }
 387
 388 static void free_one_chan(struct chan *chan, int delay_free_irq)
 389 {
 390         list_del(&chan->list);
 391
 392         close_one_chan(chan, delay_free_irq);
 393
 394         if(chan->ops->free != NULL)
 395                 (*chan->ops->free)(chan->data);
 396
 397         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 398         kfree(chan);
 399 }
 400
 401 static void free_chan(struct list_head *chans, int delay_free_irq)
 402 {
 403         struct list_head *ele, *next;
 404         struct chan *chan;
 405
 406         list_for_each_safe(ele, next, chans){
 407                 chan = list_entry(ele, struct chan, list);
 408                 free_one_chan(chan, delay_free_irq);
 409         }
 410 }
 411
 412 static int one_chan_config_string(struct chan *chan, char *str, int size,
 413                                   char **error_out)
 414 {
 415         int n = 0;
 416
 417         if(chan == NULL){
 418                 CONFIG_CHUNK(str, size, n, "none", 1);
 419                 return n;
 420         }
 421
 422         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 423
 424         if(chan->dev == NULL){
 425                 CONFIG_CHUNK(str, size, n, "", 1);
 426                 return n;
 427         }
 428
 429         CONFIG_CHUNK(str, size, n, ":", 0);
 430         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 431
 432         return n;
 433 }
 434
 435 static int chan_pair_config_string(struct chan *in, struct chan *out,
 436                                    char *str, int size, char **error_out)
 437 {
 438         int n;
 439
 440         n = one_chan_config_string(in, str, size, error_out);
 441         str += n;
 442         size -= n;
 443
 444         if(in == out){
 445                 CONFIG_CHUNK(str, size, n, "", 1);
 446                 return n;
 447         }
 448
 449         CONFIG_CHUNK(str, size, n, ",", 1);
 450         n = one_chan_config_string(out, str, size, error_out);
 451         str += n;
 452         size -= n;
 453         CONFIG_CHUNK(str, size, n, "", 1);
 454
 455         return n;
 456 }
 457
 458 int chan_config_string(struct list_head *chans, char *str, int size,
 459                        char **error_out)
 460 {
 461         struct list_head *ele;
 462         struct chan *chan, *in = NULL, *out = NULL;
 463
 464         list_for_each(ele, chans){
 465                 chan = list_entry(ele, struct chan, list);
 466                 if(!chan->primary)
 467                         continue;
 468                 if(chan->input)
 469                         in = chan;
 470                 if(chan->output)
 471                         out = chan;
 472         }
 473
 474         return chan_pair_config_string(in, out, str, size, error_out);
 475 }
 476
 477 struct chan_type {
 478         char *key;
 479         const struct chan_ops *ops;
 480 };
 481
 482 static const struct chan_type chan_table[] = {
 483         { "fd", &fd_ops },
 484
 485 #ifdef CONFIG_NULL_CHAN
 486         { "null", &null_ops },
 487 #else
 488         { "null", &not_configged_ops },
 489 #endif
 490
 491 #ifdef CONFIG_PORT_CHAN
 492         { "port", &port_ops },
 493 #else
 494         { "port", &not_configged_ops },
 495 #endif
 496
 497 #ifdef CONFIG_PTY_CHAN
 498         { "pty", &pty_ops },
 499         { "pts", &pts_ops },
 500 #else
 501         { "pty", &not_configged_ops },
 502         { "pts", &not_configged_ops },
 503 #endif
 504
 505 #ifdef CONFIG_TTY_CHAN
 506         { "tty", &tty_ops },
 507 #else
 508         { "tty", &not_configged_ops },
 509 #endif
 510
 511 #ifdef CONFIG_XTERM_CHAN
 512         { "xterm", &xterm_ops },
 513 #else
 514         { "xterm", &not_configged_ops },
 515 #endif
 516 };
 517
 518 static struct chan *parse_chan(struct line *line, char *str, int device,
 519                                const struct chan_opts *opts, char **error_out)
 520 {
 521         const struct chan_type *entry;
 522         const struct chan_ops *ops;
 523         struct chan *chan;
 524         void *data;
 525         int i;
 526
 527         ops = NULL;
 528         data = NULL;
 529         for(i = 0; i < ARRAY_SIZE(chan_table); i++){
 530                 entry = &chan_table[i];
 531                 if(!strncmp(str, entry->key, strlen(entry->key))){
 532                         ops = entry->ops;
 533                         str += strlen(entry->key);
 534                         break;
 535                 }
 536         }
 537         if(ops == NULL){
 538                 *error_out = "No match for configured backends";
 539                 return NULL;
 540         }
 541
 542         data = (*ops->init)(str, device, opts);
 543         if(data == NULL){
 544                 *error_out = "Configuration failed";
 545                 return NULL;
 546         }
 547
 548         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 549         if(chan == NULL){
 550                 *error_out = "Memory allocation failed";
 551                 return NULL;
 552         }
 553         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 554                                  .free_list     =
 555                                         LIST_HEAD_INIT(chan->free_list),
 556                                  .line          = line,
 557                                  .primary       = 1,
 558                                  .input         = 0,
 559                                  .output        = 0,
 560                                  .opened        = 0,
 561                                  .enabled       = 0,
 562                                  .fd            = -1,
 563                                  .ops           = ops,
 564                                  .data          = data });
 565         return chan;
 566 }
 567
 568 int parse_chan_pair(char *str, struct line *line, int device,
 569                     const struct chan_opts *opts, char **error_out)
 570 {
 571         struct list_head *chans = &line->chan_list;
 572         struct chan *new, *chan;
 573         char *in, *out;
 574
 575         if(!list_empty(chans)){
 576                 chan = list_entry(chans->next, struct chan, list);
 577                 free_chan(chans, 0);
 578                 INIT_LIST_HEAD(chans);
 579         }
 580
 581         out = strchr(str, ',');
 582         if(out != NULL){
 583                 in = str;
 584                 *out = '\0';
 585                 out++;
 586                 new = parse_chan(line, in, device, opts, error_out);
 587                 if(new == NULL)
 588                         return -1;
 589
 590                 new->input = 1;
 591                 list_add(&new->list, chans);
 592
 593                 new = parse_chan(line, out, device, opts, error_out);
 594                 if(new == NULL)
 595                         return -1;
 596
 597                 list_add(&new->list, chans);
 598                 new->output = 1;
 599         }
 600         else {
 601                 new = parse_chan(line, str, device, opts, error_out);
 602                 if(new == NULL)
 603                         return -1;
 604
 605                 list_add(&new->list, chans);
 606                 new->input = 1;
 607                 new->output = 1;
 608         }
 609         return 0;
 610 }
 611
 612 int chan_out_fd(struct list_head *chans)
 613 {
 614         struct list_head *ele;
 615         struct chan *chan;
 616
 617         list_for_each(ele, chans){
 618                 chan = list_entry(ele, struct chan, list);
 619                 if(chan->primary && chan->output)
 620                         return chan->fd;
 621         }
 622         return -1;
 623 }
 624
 625 void chan_interrupt(struct list_head *chans, struct delayed_work *task,
 626                     struct tty_struct *tty, int irq)
 627 {
 628         struct list_head *ele, *next;
 629         struct chan *chan;
 630         int err;
 631         char c;
 632
 633         list_for_each_safe(ele, next, chans){
 634                 chan = list_entry(ele, struct chan, list);
 635                 if(!chan->input || (chan->ops->read == NULL)) continue;
 636                 do {
 637                         if (tty && !tty_buffer_request_room(tty, 1)) {
 638                                 schedule_delayed_work(task, 1);
 639                                 goto out;
 640                         }
 641                         err = chan->ops->read(chan->fd, &c, chan->data);
 642                         if(err > 0)
 643                                 tty_receive_char(tty, c);
 644                 } while(err > 0);
 645
 646                 if(err == 0) reactivate_fd(chan->fd, irq);
 647                 if(err == -EIO){
 648                         if(chan->primary){
 649                                 if(tty != NULL)
 650                                         tty_hangup(tty);
 651                                 close_chan(chans, 1);
 652                                 return;
 653                         }
 654                         else close_one_chan(chan, 1);
 655                 }
 656         }
 657  out:
 658         if(tty) tty_flip_buffer_push(tty);
 659 }