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 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         if((tty->flip.flag_buf_ptr == NULL) ||
 190            (tty->flip.char_buf_ptr == NULL))
 191                 return;
 192         tty_insert_flip_char(tty, ch, TTY_NORMAL);
 193 }
 194
 195 static int open_one_chan(struct chan *chan)
 196 {
 197         int fd;
 198
 199         if(chan->opened)
 200                 return 0;
 201
 202         if(chan->ops->open == NULL)
 203                 fd = 0;
 204         else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
 205                                      chan->data, &chan->dev);
 206         if(fd < 0)
 207                 return fd;
 208         chan->fd = fd;
 209
 210         chan->opened = 1;
 211         return 0;
 212 }
 213
 214 int open_chan(struct list_head *chans)
 215 {
 216         struct list_head *ele;
 217         struct chan *chan;
 218         int ret, err = 0;
 219
 220         list_for_each(ele, chans){
 221                 chan = list_entry(ele, struct chan, list);
 222                 ret = open_one_chan(chan);
 223                 if(chan->primary)
 224                         err = ret;
 225         }
 226         return err;
 227 }
 228
 229 void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
 230 {
 231         struct list_head *ele;
 232         struct chan *chan;
 233
 234         list_for_each(ele, chans){
 235                 chan = list_entry(ele, struct chan, list);
 236                 if(chan->primary && chan->output && chan->ops->winch){
 237                         register_winch(chan->fd, tty);
 238                         return;
 239                 }
 240         }
 241 }
 242
 243 void enable_chan(struct list_head *chans, struct tty_struct *tty)
 244 {
 245         struct list_head *ele;
 246         struct chan *chan;
 247
 248         list_for_each(ele, chans){
 249                 chan = list_entry(ele, struct chan, list);
 250                 if(!chan->opened) continue;
 251
 252                 line_setup_irq(chan->fd, chan->input, chan->output, tty);
 253         }
 254 }
 255
 256 void close_chan(struct list_head *chans)
 257 {
 258         struct chan *chan;
 259
 260         /* Close in reverse order as open in case more than one of them
 261          * refers to the same device and they save and restore that device's
 262          * state.  Then, the first one opened will have the original state,
 263          * so it must be the last closed.
 264          */
 265         list_for_each_entry_reverse(chan, chans, list) {
 266                 if(!chan->opened) continue;
 267                 if(chan->ops->close != NULL)
 268                         (*chan->ops->close)(chan->fd, chan->data);
 269                 chan->opened = 0;
 270                 chan->fd = -1;
 271         }
 272 }
 273
 274 int write_chan(struct list_head *chans, const char *buf, int len,
 275                int write_irq)
 276 {
 277         struct list_head *ele;
 278         struct chan *chan = NULL;
 279         int n, ret = 0;
 280
 281         list_for_each(ele, chans) {
 282                 chan = list_entry(ele, struct chan, list);
 283                 if (!chan->output || (chan->ops->write == NULL))
 284                         continue;
 285                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 286                 if (chan->primary) {
 287                         ret = n;
 288                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 289                                 reactivate_fd(chan->fd, write_irq);
 290                 }
 291         }
 292         return ret;
 293 }
 294
 295 int console_write_chan(struct list_head *chans, const char *buf, int len)
 296 {
 297         struct list_head *ele;
 298         struct chan *chan;
 299         int n, ret = 0;
 300
 301         list_for_each(ele, chans){
 302                 chan = list_entry(ele, struct chan, list);
 303                 if(!chan->output || (chan->ops->console_write == NULL))
 304                         continue;
 305                 n = chan->ops->console_write(chan->fd, buf, len);
 306                 if(chan->primary) ret = n;
 307         }
 308         return ret;
 309 }
 310
 311 int console_open_chan(struct line *line, struct console *co,
 312                       struct chan_opts *opts)
 313 {
 314         if (!list_empty(&line->chan_list))
 315                 return 0;
 316
 317         if (0 != parse_chan_pair(line->init_str, &line->chan_list,
 318                                  line->init_pri, co->index, opts))
 319                 return -1;
 320         if (0 != open_chan(&line->chan_list))
 321                 return -1;
 322         printk("Console initialized on /dev/%s%d\n",co->name,co->index);
 323         return 0;
 324 }
 325
 326 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 327                       unsigned short *cols_out)
 328 {
 329         struct list_head *ele;
 330         struct chan *chan;
 331
 332         list_for_each(ele, chans){
 333                 chan = list_entry(ele, struct chan, list);
 334                 if(chan->primary){
 335                         if(chan->ops->window_size == NULL)
 336                                 return 0;
 337                         return chan->ops->window_size(chan->fd, chan->data,
 338                                                       rows_out, cols_out);
 339                 }
 340         }
 341         return 0;
 342 }
 343
 344 void free_one_chan(struct chan *chan)
 345 {
 346         list_del(&chan->list);
 347         if(chan->ops->free != NULL)
 348                 (*chan->ops->free)(chan->data);
 349         free_irq_by_fd(chan->fd);
 350         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 351         kfree(chan);
 352 }
 353
 354 void free_chan(struct list_head *chans)
 355 {
 356         struct list_head *ele, *next;
 357         struct chan *chan;
 358
 359         list_for_each_safe(ele, next, chans){
 360                 chan = list_entry(ele, struct chan, list);
 361                 free_one_chan(chan);
 362         }
 363 }
 364
 365 static int one_chan_config_string(struct chan *chan, char *str, int size,
 366                                   char **error_out)
 367 {
 368         int n = 0;
 369
 370         if(chan == NULL){
 371                 CONFIG_CHUNK(str, size, n, "none", 1);
 372                 return n;
 373         }
 374
 375         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 376
 377         if(chan->dev == NULL){
 378                 CONFIG_CHUNK(str, size, n, "", 1);
 379                 return n;
 380         }
 381
 382         CONFIG_CHUNK(str, size, n, ":", 0);
 383         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 384
 385         return n;
 386 }
 387
 388 static int chan_pair_config_string(struct chan *in, struct chan *out,
 389                                    char *str, int size, char **error_out)
 390 {
 391         int n;
 392
 393         n = one_chan_config_string(in, str, size, error_out);
 394         str += n;
 395         size -= n;
 396
 397         if(in == out){
 398                 CONFIG_CHUNK(str, size, n, "", 1);
 399                 return n;
 400         }
 401
 402         CONFIG_CHUNK(str, size, n, ",", 1);
 403         n = one_chan_config_string(out, str, size, error_out);
 404         str += n;
 405         size -= n;
 406         CONFIG_CHUNK(str, size, n, "", 1);
 407
 408         return n;
 409 }
 410
 411 int chan_config_string(struct list_head *chans, char *str, int size,
 412                        char **error_out)
 413 {
 414         struct list_head *ele;
 415         struct chan *chan, *in = NULL, *out = NULL;
 416
 417         list_for_each(ele, chans){
 418                 chan = list_entry(ele, struct chan, list);
 419                 if(!chan->primary)
 420                         continue;
 421                 if(chan->input)
 422                         in = chan;
 423                 if(chan->output)
 424                         out = chan;
 425         }
 426
 427         return chan_pair_config_string(in, out, str, size, error_out);
 428 }
 429
 430 struct chan_type {
 431         char *key;
 432         struct chan_ops *ops;
 433 };
 434
 435 struct chan_type chan_table[] = {
 436         { "fd", &fd_ops },
 437
 438 #ifdef CONFIG_NULL_CHAN
 439         { "null", &null_ops },
 440 #else
 441         { "null", &not_configged_ops },
 442 #endif
 443
 444 #ifdef CONFIG_PORT_CHAN
 445         { "port", &port_ops },
 446 #else
 447         { "port", &not_configged_ops },
 448 #endif
 449
 450 #ifdef CONFIG_PTY_CHAN
 451         { "pty", &pty_ops },
 452         { "pts", &pts_ops },
 453 #else
 454         { "pty", &not_configged_ops },
 455         { "pts", &not_configged_ops },
 456 #endif
 457
 458 #ifdef CONFIG_TTY_CHAN
 459         { "tty", &tty_ops },
 460 #else
 461         { "tty", &not_configged_ops },
 462 #endif
 463
 464 #ifdef CONFIG_XTERM_CHAN
 465         { "xterm", &xterm_ops },
 466 #else
 467         { "xterm", &not_configged_ops },
 468 #endif
 469 };
 470
 471 static struct chan *parse_chan(char *str, int pri, int device,
 472                                struct chan_opts *opts)
 473 {
 474         struct chan_type *entry;
 475         struct chan_ops *ops;
 476         struct chan *chan;
 477         void *data;
 478         int i;
 479
 480         ops = NULL;
 481         data = NULL;
 482         for(i = 0; i < sizeof(chan_table)/sizeof(chan_table[0]); i++){
 483                 entry = &chan_table[i];
 484                 if(!strncmp(str, entry->key, strlen(entry->key))){
 485                         ops = entry->ops;
 486                         str += strlen(entry->key);
 487                         break;
 488                 }
 489         }
 490         if(ops == NULL){
 491                 my_printf("parse_chan couldn't parse \"%s\"\n",
 492                        str);
 493                 return NULL;
 494         }
 495         if(ops->init == NULL)
 496                 return NULL;
 497         data = (*ops->init)(str, device, opts);
 498         if(data == NULL)
 499                 return NULL;
 500
 501         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 502         if(chan == NULL)
 503                 return NULL;
 504         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 505                                  .primary       = 1,
 506                                  .input         = 0,
 507                                  .output        = 0,
 508                                  .opened        = 0,
 509                                  .fd            = -1,
 510                                  .pri           = pri,
 511                                  .ops           = ops,
 512                                  .data          = data });
 513         return chan;
 514 }
 515
 516 int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
 517                     struct chan_opts *opts)
 518 {
 519         struct chan *new, *chan;
 520         char *in, *out;
 521
 522         if(!list_empty(chans)){
 523                 chan = list_entry(chans->next, struct chan, list);
 524                 if(chan->pri >= pri)
 525                         return 0;
 526                 free_chan(chans);
 527                 INIT_LIST_HEAD(chans);
 528         }
 529
 530         out = strchr(str, ',');
 531         if(out != NULL){
 532                 in = str;
 533                 *out = '\0';
 534                 out++;
 535                 new = parse_chan(in, pri, device, opts);
 536                 if(new == NULL)
 537                         return -1;
 538
 539                 new->input = 1;
 540                 list_add(&new->list, chans);
 541
 542                 new = parse_chan(out, pri, device, opts);
 543                 if(new == NULL)
 544                         return -1;
 545
 546                 list_add(&new->list, chans);
 547                 new->output = 1;
 548         }
 549         else {
 550                 new = parse_chan(str, pri, device, opts);
 551                 if(new == NULL)
 552                         return -1;
 553
 554                 list_add(&new->list, chans);
 555                 new->input = 1;
 556                 new->output = 1;
 557         }
 558         return 0;
 559 }
 560
 561 int chan_out_fd(struct list_head *chans)
 562 {
 563         struct list_head *ele;
 564         struct chan *chan;
 565
 566         list_for_each(ele, chans){
 567                 chan = list_entry(ele, struct chan, list);
 568                 if(chan->primary && chan->output)
 569                         return chan->fd;
 570         }
 571         return -1;
 572 }
 573
 574 void chan_interrupt(struct list_head *chans, struct work_struct *task,
 575                     struct tty_struct *tty, int irq)
 576 {
 577         struct list_head *ele, *next;
 578         struct chan *chan;
 579         int err;
 580         char c;
 581
 582         list_for_each_safe(ele, next, chans){
 583                 chan = list_entry(ele, struct chan, list);
 584                 if(!chan->input || (chan->ops->read == NULL)) continue;
 585                 do {
 586                         if((tty != NULL) &&
 587                            (tty->flip.count >= TTY_FLIPBUF_SIZE)){
 588                                 schedule_work(task);
 589                                 goto out;
 590                         }
 591                         err = chan->ops->read(chan->fd, &c, chan->data);
 592                         if(err > 0)
 593                                 tty_receive_char(tty, c);
 594                 } while(err > 0);
 595
 596                 if(err == 0) reactivate_fd(chan->fd, irq);
 597                 if(err == -EIO){
 598                         if(chan->primary){
 599                                 if(tty != NULL)
 600                                         tty_hangup(tty);
 601                                 line_disable(tty, irq);
 602                                 close_chan(chans);
 603                                 free_chan(chans);
 604                                 return;
 605                         }
 606                         else {
 607                                 if(chan->ops->close != NULL)
 608                                         chan->ops->close(chan->fd, chan->data);
 609                                 free_one_chan(chan);
 610                         }
 611                 }
 612         }
 613  out:
 614         if(tty) tty_flip_buffer_push(tty);
 615 }
 616
 617 /*
 618  * Overrides for Emacs so that we follow Linus's tabbing style.
 619  * Emacs will notice this stuff at the end of the file and automatically
 620  * adjust the settings for this buffer only.  This must remain at the end
 621  * of the file.
 622  * ---------------------------------------------------------------------------
 623  * Local variables:
 624  * c-file-style: "linux"
 625  * End:
 626  */