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 "user_util.h"
  16 #include "kern.h"
  17 #include "irq_user.h"
  18 #include "sigio.h"
  19 #include "line.h"
  20 #include "os.h"
  21
  22 /* XXX: could well be moved to somewhere else, if needed. */
  23 static int my_printf(const char * fmt, ...)
  24         __attribute__ ((format (printf, 1, 2)));
  25
  26 static int my_printf(const char * fmt, ...)
  27 {
  28         /* Yes, can be called on atomic context.*/
  29         char *buf = kmalloc(4096, GFP_ATOMIC);
  30         va_list args;
  31         int r;
  32
  33         if (!buf) {
  34                 /* We print directly fmt.
  35                  * Yes, yes, yes, feel free to complain. */
  36                 r = strlen(fmt);
  37         } else {
  38                 va_start(args, fmt);
  39                 r = vsprintf(buf, fmt, args);
  40                 va_end(args);
  41                 fmt = buf;
  42         }
  43
  44         if (r)
  45                 r = os_write_file(1, fmt, r);
  46         return r;
  47
  48 }
  49
  50 #ifdef CONFIG_NOCONFIG_CHAN
  51 /* Despite its name, there's no added trailing newline. */
  52 static int my_puts(const char * buf)
  53 {
  54         return os_write_file(1, buf, strlen(buf));
  55 }
  56
  57 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
  58 {
  59         my_puts("Using a channel type which is configured out of "
  60                "UML\n");
  61         return NULL;
  62 }
  63
  64 static int not_configged_open(int input, int output, int primary, void *data,
  65                               char **dev_out)
  66 {
  67         my_puts("Using a channel type which is configured out of "
  68                "UML\n");
  69         return -ENODEV;
  70 }
  71
  72 static void not_configged_close(int fd, void *data)
  73 {
  74         my_puts("Using a channel type which is configured out of "
  75                "UML\n");
  76 }
  77
  78 static int not_configged_read(int fd, char *c_out, void *data)
  79 {
  80         my_puts("Using a channel type which is configured out of "
  81                "UML\n");
  82         return -EIO;
  83 }
  84
  85 static int not_configged_write(int fd, const char *buf, int len, void *data)
  86 {
  87         my_puts("Using a channel type which is configured out of "
  88                "UML\n");
  89         return -EIO;
  90 }
  91
  92 static int not_configged_console_write(int fd, const char *buf, int len)
  93 {
  94         my_puts("Using a channel type which is configured out of "
  95                "UML\n");
  96         return -EIO;
  97 }
  98
  99 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
 100                                      unsigned short *cols)
 101 {
 102         my_puts("Using a channel type which is configured out of "
 103                "UML\n");
 104         return -ENODEV;
 105 }
 106
 107 static void not_configged_free(void *data)
 108 {
 109         my_puts("Using a channel type which is configured out of "
 110                "UML\n");
 111 }
 112
 113 static const struct chan_ops not_configged_ops = {
 114         .init           = not_configged_init,
 115         .open           = not_configged_open,
 116         .close          = not_configged_close,
 117         .read           = not_configged_read,
 118         .write          = not_configged_write,
 119         .console_write  = not_configged_console_write,
 120         .window_size    = not_configged_window_size,
 121         .free           = not_configged_free,
 122         .winch          = 0,
 123 };
 124 #endif /* CONFIG_NOCONFIG_CHAN */
 125
 126 void generic_close(int fd, void *unused)
 127 {
 128         os_close_file(fd);
 129 }
 130
 131 int generic_read(int fd, char *c_out, void *unused)
 132 {
 133         int n;
 134
 135         n = os_read_file(fd, c_out, sizeof(*c_out));
 136
 137         if(n == -EAGAIN)
 138                 return 0;
 139         else if(n == 0)
 140                 return -EIO;
 141         return n;
 142 }
 143
 144 /* XXX Trivial wrapper around os_write_file */
 145
 146 int generic_write(int fd, const char *buf, int n, void *unused)
 147 {
 148         return os_write_file(fd, buf, n);
 149 }
 150
 151 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 152                         unsigned short *cols_out)
 153 {
 154         int rows, cols;
 155         int ret;
 156
 157         ret = os_window_size(fd, &rows, &cols);
 158         if(ret < 0)
 159                 return ret;
 160
 161         ret = ((*rows_out != rows) || (*cols_out != cols));
 162
 163         *rows_out = rows;
 164         *cols_out = cols;
 165
 166         return ret;
 167 }
 168
 169 void generic_free(void *data)
 170 {
 171         kfree(data);
 172 }
 173
 174 static void tty_receive_char(struct tty_struct *tty, char ch)
 175 {
 176         if(tty == NULL) return;
 177
 178         if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
 179                 if(ch == STOP_CHAR(tty)){
 180                         stop_tty(tty);
 181                         return;
 182                 }
 183                 else if(ch == START_CHAR(tty)){
 184                         start_tty(tty);
 185                         return;
 186                 }
 187         }
 188
 189         tty_insert_flip_char(tty, ch, TTY_NORMAL);
 190 }
 191
 192 static int open_one_chan(struct chan *chan)
 193 {
 194         int fd;
 195
 196         if(chan->opened)
 197                 return 0;
 198
 199         if(chan->ops->open == NULL)
 200                 fd = 0;
 201         else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
 202                                      chan->data, &chan->dev);
 203         if(fd < 0)
 204                 return fd;
 205         chan->fd = fd;
 206
 207         chan->opened = 1;
 208         return 0;
 209 }
 210
 211 int open_chan(struct list_head *chans)
 212 {
 213         struct list_head *ele;
 214         struct chan *chan;
 215         int ret, err = 0;
 216
 217         list_for_each(ele, chans){
 218                 chan = list_entry(ele, struct chan, list);
 219                 ret = open_one_chan(chan);
 220                 if(chan->primary)
 221                         err = ret;
 222         }
 223         return err;
 224 }
 225
 226 void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
 227 {
 228         struct list_head *ele;
 229         struct chan *chan;
 230
 231         list_for_each(ele, chans){
 232                 chan = list_entry(ele, struct chan, list);
 233                 if(chan->primary && chan->output && chan->ops->winch){
 234                         register_winch(chan->fd, tty);
 235                         return;
 236                 }
 237         }
 238 }
 239
 240 void enable_chan(struct line *line)
 241 {
 242         struct list_head *ele;
 243         struct chan *chan;
 244
 245         list_for_each(ele, &line->chan_list){
 246                 chan = list_entry(ele, struct chan, list);
 247                 if(open_one_chan(chan))
 248                         continue;
 249
 250                 if(chan->enabled)
 251                         continue;
 252                 line_setup_irq(chan->fd, chan->input, chan->output, line,
 253                                chan);
 254                 chan->enabled = 1;
 255         }
 256 }
 257
 258 static LIST_HEAD(irqs_to_free);
 259
 260 void free_irqs(void)
 261 {
 262         struct chan *chan;
 263
 264         while(!list_empty(&irqs_to_free)){
 265                 chan = list_entry(irqs_to_free.next, struct chan, free_list);
 266                 list_del(&chan->free_list);
 267
 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 }
 275
 276 static void close_one_chan(struct chan *chan, int delay_free_irq)
 277 {
 278         if(!chan->opened)
 279                 return;
 280
 281         if(delay_free_irq){
 282                 list_add(&chan->free_list, &irqs_to_free);
 283         }
 284         else {
 285                 if(chan->input)
 286                         free_irq(chan->line->driver->read_irq, chan);
 287                 if(chan->output)
 288                         free_irq(chan->line->driver->write_irq, chan);
 289                 chan->enabled = 0;
 290         }
 291         if(chan->ops->close != NULL)
 292                 (*chan->ops->close)(chan->fd, chan->data);
 293
 294         chan->opened = 0;
 295         chan->fd = -1;
 296 }
 297
 298 void close_chan(struct list_head *chans, int delay_free_irq)
 299 {
 300         struct chan *chan;
 301
 302         /* Close in reverse order as open in case more than one of them
 303          * refers to the same device and they save and restore that device's
 304          * state.  Then, the first one opened will have the original state,
 305          * so it must be the last closed.
 306          */
 307         list_for_each_entry_reverse(chan, chans, list) {
 308                 close_one_chan(chan, delay_free_irq);
 309         }
 310 }
 311
 312 void deactivate_chan(struct list_head *chans, int irq)
 313 {
 314         struct list_head *ele;
 315
 316         struct chan *chan;
 317         list_for_each(ele, chans) {
 318                 chan = list_entry(ele, struct chan, list);
 319
 320                 if(chan->enabled && chan->input)
 321                         deactivate_fd(chan->fd, irq);
 322         }
 323 }
 324
 325 void reactivate_chan(struct list_head *chans, int irq)
 326 {
 327         struct list_head *ele;
 328         struct chan *chan;
 329
 330         list_for_each(ele, chans) {
 331                 chan = list_entry(ele, struct chan, list);
 332
 333                 if(chan->enabled && chan->input)
 334                         reactivate_fd(chan->fd, irq);
 335         }
 336 }
 337
 338 int write_chan(struct list_head *chans, const char *buf, int len,
 339                int write_irq)
 340 {
 341         struct list_head *ele;
 342         struct chan *chan = NULL;
 343         int n, ret = 0;
 344
 345         list_for_each(ele, chans) {
 346                 chan = list_entry(ele, struct chan, list);
 347                 if (!chan->output || (chan->ops->write == NULL))
 348                         continue;
 349                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 350                 if (chan->primary) {
 351                         ret = n;
 352                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 353                                 reactivate_fd(chan->fd, write_irq);
 354                 }
 355         }
 356         return ret;
 357 }
 358
 359 int console_write_chan(struct list_head *chans, const char *buf, int len)
 360 {
 361         struct list_head *ele;
 362         struct chan *chan;
 363         int n, ret = 0;
 364
 365         list_for_each(ele, chans){
 366                 chan = list_entry(ele, struct chan, list);
 367                 if(!chan->output || (chan->ops->console_write == NULL))
 368                         continue;
 369                 n = chan->ops->console_write(chan->fd, buf, len);
 370                 if(chan->primary) ret = n;
 371         }
 372         return ret;
 373 }
 374
 375 int console_open_chan(struct line *line, struct console *co,
 376                       const struct chan_opts *opts)
 377 {
 378         int err;
 379
 380         err = open_chan(&line->chan_list);
 381         if(err)
 382                 return err;
 383
 384         printk("Console initialized on /dev/%s%d\n",co->name,co->index);
 385         return 0;
 386 }
 387
 388 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 389                       unsigned short *cols_out)
 390 {
 391         struct list_head *ele;
 392         struct chan *chan;
 393
 394         list_for_each(ele, chans){
 395                 chan = list_entry(ele, struct chan, list);
 396                 if(chan->primary){
 397                         if(chan->ops->window_size == NULL)
 398                                 return 0;
 399                         return chan->ops->window_size(chan->fd, chan->data,
 400                                                       rows_out, cols_out);
 401                 }
 402         }
 403         return 0;
 404 }
 405
 406 static void free_one_chan(struct chan *chan, int delay_free_irq)
 407 {
 408         list_del(&chan->list);
 409
 410         close_one_chan(chan, delay_free_irq);
 411
 412         if(chan->ops->free != NULL)
 413                 (*chan->ops->free)(chan->data);
 414
 415         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 416         kfree(chan);
 417 }
 418
 419 static void free_chan(struct list_head *chans, int delay_free_irq)
 420 {
 421         struct list_head *ele, *next;
 422         struct chan *chan;
 423
 424         list_for_each_safe(ele, next, chans){
 425                 chan = list_entry(ele, struct chan, list);
 426                 free_one_chan(chan, delay_free_irq);
 427         }
 428 }
 429
 430 static int one_chan_config_string(struct chan *chan, char *str, int size,
 431                                   char **error_out)
 432 {
 433         int n = 0;
 434
 435         if(chan == NULL){
 436                 CONFIG_CHUNK(str, size, n, "none", 1);
 437                 return n;
 438         }
 439
 440         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 441
 442         if(chan->dev == NULL){
 443                 CONFIG_CHUNK(str, size, n, "", 1);
 444                 return n;
 445         }
 446
 447         CONFIG_CHUNK(str, size, n, ":", 0);
 448         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 449
 450         return n;
 451 }
 452
 453 static int chan_pair_config_string(struct chan *in, struct chan *out,
 454                                    char *str, int size, char **error_out)
 455 {
 456         int n;
 457
 458         n = one_chan_config_string(in, str, size, error_out);
 459         str += n;
 460         size -= n;
 461
 462         if(in == out){
 463                 CONFIG_CHUNK(str, size, n, "", 1);
 464                 return n;
 465         }
 466
 467         CONFIG_CHUNK(str, size, n, ",", 1);
 468         n = one_chan_config_string(out, str, size, error_out);
 469         str += n;
 470         size -= n;
 471         CONFIG_CHUNK(str, size, n, "", 1);
 472
 473         return n;
 474 }
 475
 476 int chan_config_string(struct list_head *chans, char *str, int size,
 477                        char **error_out)
 478 {
 479         struct list_head *ele;
 480         struct chan *chan, *in = NULL, *out = NULL;
 481
 482         list_for_each(ele, chans){
 483                 chan = list_entry(ele, struct chan, list);
 484                 if(!chan->primary)
 485                         continue;
 486                 if(chan->input)
 487                         in = chan;
 488                 if(chan->output)
 489                         out = chan;
 490         }
 491
 492         return chan_pair_config_string(in, out, str, size, error_out);
 493 }
 494
 495 struct chan_type {
 496         char *key;
 497         const struct chan_ops *ops;
 498 };
 499
 500 static const struct chan_type chan_table[] = {
 501         { "fd", &fd_ops },
 502
 503 #ifdef CONFIG_NULL_CHAN
 504         { "null", &null_ops },
 505 #else
 506         { "null", &not_configged_ops },
 507 #endif
 508
 509 #ifdef CONFIG_PORT_CHAN
 510         { "port", &port_ops },
 511 #else
 512         { "port", &not_configged_ops },
 513 #endif
 514
 515 #ifdef CONFIG_PTY_CHAN
 516         { "pty", &pty_ops },
 517         { "pts", &pts_ops },
 518 #else
 519         { "pty", &not_configged_ops },
 520         { "pts", &not_configged_ops },
 521 #endif
 522
 523 #ifdef CONFIG_TTY_CHAN
 524         { "tty", &tty_ops },
 525 #else
 526         { "tty", &not_configged_ops },
 527 #endif
 528
 529 #ifdef CONFIG_XTERM_CHAN
 530         { "xterm", &xterm_ops },
 531 #else
 532         { "xterm", &not_configged_ops },
 533 #endif
 534 };
 535
 536 static struct chan *parse_chan(struct line *line, char *str, int device,
 537                                const struct chan_opts *opts)
 538 {
 539         const struct chan_type *entry;
 540         const struct chan_ops *ops;
 541         struct chan *chan;
 542         void *data;
 543         int i;
 544
 545         ops = NULL;
 546         data = NULL;
 547         for(i = 0; i < ARRAY_SIZE(chan_table); i++){
 548                 entry = &chan_table[i];
 549                 if(!strncmp(str, entry->key, strlen(entry->key))){
 550                         ops = entry->ops;
 551                         str += strlen(entry->key);
 552                         break;
 553                 }
 554         }
 555         if(ops == NULL){
 556                 my_printf("parse_chan couldn't parse \"%s\"\n",
 557                        str);
 558                 return NULL;
 559         }
 560         if(ops->init == NULL)
 561                 return NULL;
 562         data = (*ops->init)(str, device, opts);
 563         if(data == NULL)
 564                 return NULL;
 565
 566         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 567         if(chan == NULL)
 568                 return NULL;
 569         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 570                                  .free_list     =
 571                                         LIST_HEAD_INIT(chan->free_list),
 572                                  .line          = line,
 573                                  .primary       = 1,
 574                                  .input         = 0,
 575                                  .output        = 0,
 576                                  .opened        = 0,
 577                                  .enabled       = 0,
 578                                  .fd            = -1,
 579                                  .ops           = ops,
 580                                  .data          = data });
 581         return chan;
 582 }
 583
 584 int parse_chan_pair(char *str, struct line *line, int device,
 585                     const struct chan_opts *opts)
 586 {
 587         struct list_head *chans = &line->chan_list;
 588         struct chan *new, *chan;
 589         char *in, *out;
 590
 591         if(!list_empty(chans)){
 592                 chan = list_entry(chans->next, struct chan, list);
 593                 free_chan(chans, 0);
 594                 INIT_LIST_HEAD(chans);
 595         }
 596
 597         out = strchr(str, ',');
 598         if(out != NULL){
 599                 in = str;
 600                 *out = '\0';
 601                 out++;
 602                 new = parse_chan(line, in, device, opts);
 603                 if(new == NULL)
 604                         return -1;
 605
 606                 new->input = 1;
 607                 list_add(&new->list, chans);
 608
 609                 new = parse_chan(line, out, device, opts);
 610                 if(new == NULL)
 611                         return -1;
 612
 613                 list_add(&new->list, chans);
 614                 new->output = 1;
 615         }
 616         else {
 617                 new = parse_chan(line, str, device, opts);
 618                 if(new == NULL)
 619                         return -1;
 620
 621                 list_add(&new->list, chans);
 622                 new->input = 1;
 623                 new->output = 1;
 624         }
 625         return 0;
 626 }
 627
 628 int chan_out_fd(struct list_head *chans)
 629 {
 630         struct list_head *ele;
 631         struct chan *chan;
 632
 633         list_for_each(ele, chans){
 634                 chan = list_entry(ele, struct chan, list);
 635                 if(chan->primary && chan->output)
 636                         return chan->fd;
 637         }
 638         return -1;
 639 }
 640
 641 void chan_interrupt(struct list_head *chans, struct work_struct *task,
 642                     struct tty_struct *tty, int irq)
 643 {
 644         struct list_head *ele, *next;
 645         struct chan *chan;
 646         int err;
 647         char c;
 648
 649         list_for_each_safe(ele, next, chans){
 650                 chan = list_entry(ele, struct chan, list);
 651                 if(!chan->input || (chan->ops->read == NULL)) continue;
 652                 do {
 653                         if (tty && !tty_buffer_request_room(tty, 1)) {
 654                                 schedule_delayed_work(task, 1);
 655                                 goto out;
 656                         }
 657                         err = chan->ops->read(chan->fd, &c, chan->data);
 658                         if(err > 0)
 659                                 tty_receive_char(tty, c);
 660                 } while(err > 0);
 661
 662                 if(err == 0) reactivate_fd(chan->fd, irq);
 663                 if(err == -EIO){
 664                         if(chan->primary){
 665                                 if(tty != NULL)
 666                                         tty_hangup(tty);
 667                                 close_chan(chans, 1);
 668                                 return;
 669                         }
 670                         else close_one_chan(chan, 1);
 671                 }
 672         }
 673  out:
 674         if(tty) tty_flip_buffer_push(tty);
 675 }