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 #ifdef CONFIG_NOCONFIG_CHAN
  23 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
  24 {
  25         printk(KERN_ERR "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(KERN_ERR "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(KERN_ERR "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(KERN_ERR "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(KERN_ERR "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                                        void *data)
  60 {
  61         printk(KERN_ERR "Using a channel type which is configured out of "
  62                "UML\n");
  63         return(-EIO);
  64 }
  65
  66 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
  67                                      unsigned short *cols)
  68 {
  69         printk(KERN_ERR "Using a channel type which is configured out of "
  70                "UML\n");
  71         return(-ENODEV);
  72 }
  73
  74 static void not_configged_free(void *data)
  75 {
  76         printk(KERN_ERR "Using a channel type which is configured out of "
  77                "UML\n");
  78 }
  79
  80 static struct chan_ops not_configged_ops = {
  81         .init           = not_configged_init,
  82         .open           = not_configged_open,
  83         .close          = not_configged_close,
  84         .read           = not_configged_read,
  85         .write          = not_configged_write,
  86         .console_write  = not_configged_console_write,
  87         .window_size    = not_configged_window_size,
  88         .free           = not_configged_free,
  89         .winch          = 0,
  90 };
  91 #endif /* CONFIG_NOCONFIG_CHAN */
  92
  93 void generic_close(int fd, void *unused)
  94 {
  95         os_close_file(fd);
  96 }
  97
  98 int generic_read(int fd, char *c_out, void *unused)
  99 {
 100         int n;
 101
 102         n = os_read_file(fd, c_out, sizeof(*c_out));
 103
 104         if(n == -EAGAIN)
 105                 return(0);
 106         else if(n == 0)
 107                 return(-EIO);
 108         return(n);
 109 }
 110
 111 /* XXX Trivial wrapper around os_write_file */
 112
 113 int generic_write(int fd, const char *buf, int n, void *unused)
 114 {
 115         return(os_write_file(fd, buf, n));
 116 }
 117
 118 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 119                         unsigned short *cols_out)
 120 {
 121         int rows, cols;
 122         int ret;
 123
 124         ret = os_window_size(fd, &rows, &cols);
 125         if(ret < 0)
 126                 return(ret);
 127
 128         ret = ((*rows_out != rows) || (*cols_out != cols));
 129
 130         *rows_out = rows;
 131         *cols_out = cols;
 132
 133         return(ret);
 134 }
 135
 136 void generic_free(void *data)
 137 {
 138         kfree(data);
 139 }
 140
 141 static void tty_receive_char(struct tty_struct *tty, char ch)
 142 {
 143         if(tty == NULL) return;
 144
 145         if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
 146                 if(ch == STOP_CHAR(tty)){
 147                         stop_tty(tty);
 148                         return;
 149                 }
 150                 else if(ch == START_CHAR(tty)){
 151                         start_tty(tty);
 152                         return;
 153                 }
 154         }
 155
 156         if((tty->flip.flag_buf_ptr == NULL) ||
 157            (tty->flip.char_buf_ptr == NULL))
 158                 return;
 159         tty_insert_flip_char(tty, ch, TTY_NORMAL);
 160 }
 161
 162 static int open_one_chan(struct chan *chan, int input, int output, int primary)
 163 {
 164         int fd;
 165
 166         if(chan->opened) return(0);
 167         if(chan->ops->open == NULL) fd = 0;
 168         else fd = (*chan->ops->open)(input, output, primary, chan->data,
 169                                      &chan->dev);
 170         if(fd < 0) 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, chan->input, chan->output,
 186                                     chan->primary);
 187                 if(chan->primary) 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 list_head *chans, struct tty_struct *tty)
 207 {
 208         struct list_head *ele;
 209         struct chan *chan;
 210
 211         list_for_each(ele, chans){
 212                 chan = list_entry(ele, struct chan, list);
 213                 if(!chan->opened) continue;
 214
 215                 line_setup_irq(chan->fd, chan->input, chan->output, tty);
 216         }
 217 }
 218
 219 void close_chan(struct list_head *chans)
 220 {
 221         struct chan *chan;
 222
 223         /* Close in reverse order as open in case more than one of them
 224          * refers to the same device and they save and restore that device's
 225          * state.  Then, the first one opened will have the original state,
 226          * so it must be the last closed.
 227          */
 228         list_for_each_entry_reverse(chan, chans, list) {
 229                 if(!chan->opened) continue;
 230                 if(chan->ops->close != NULL)
 231                         (*chan->ops->close)(chan->fd, chan->data);
 232                 chan->opened = 0;
 233                 chan->fd = -1;
 234         }
 235 }
 236
 237 int write_chan(struct list_head *chans, const char *buf, int len,
 238                int write_irq)
 239 {
 240         struct list_head *ele;
 241         struct chan *chan = NULL;
 242         int n, ret = 0;
 243
 244         list_for_each(ele, chans) {
 245                 chan = list_entry(ele, struct chan, list);
 246                 if (!chan->output || (chan->ops->write == NULL))
 247                         continue;
 248                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 249                 if (chan->primary) {
 250                         ret = n;
 251                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 252                                 reactivate_fd(chan->fd, write_irq);
 253                 }
 254         }
 255         return(ret);
 256 }
 257
 258 int console_write_chan(struct list_head *chans, const char *buf, int len)
 259 {
 260         struct list_head *ele;
 261         struct chan *chan;
 262         int n, ret = 0;
 263
 264         list_for_each(ele, chans){
 265                 chan = list_entry(ele, struct chan, list);
 266                 if(!chan->output || (chan->ops->console_write == NULL))
 267                         continue;
 268                 n = chan->ops->console_write(chan->fd, buf, len, chan->data);
 269                 if(chan->primary) ret = n;
 270         }
 271         return(ret);
 272 }
 273
 274 int console_open_chan(struct line *line, struct console *co, struct chan_opts *opts)
 275 {
 276         if (!list_empty(&line->chan_list))
 277                 return 0;
 278
 279         if (0 != parse_chan_pair(line->init_str, &line->chan_list,
 280                                  line->init_pri, co->index, opts))
 281                 return -1;
 282         if (0 != open_chan(&line->chan_list))
 283                 return -1;
 284         printk("Console initialized on /dev/%s%d\n",co->name,co->index);
 285         return 0;
 286 }
 287
 288 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 289                       unsigned short *cols_out)
 290 {
 291         struct list_head *ele;
 292         struct chan *chan;
 293
 294         list_for_each(ele, chans){
 295                 chan = list_entry(ele, struct chan, list);
 296                 if(chan->primary){
 297                         if(chan->ops->window_size == NULL) return(0);
 298                         return(chan->ops->window_size(chan->fd, chan->data,
 299                                                       rows_out, cols_out));
 300                 }
 301         }
 302         return(0);
 303 }
 304
 305 void free_one_chan(struct chan *chan)
 306 {
 307         list_del(&chan->list);
 308         if(chan->ops->free != NULL)
 309                 (*chan->ops->free)(chan->data);
 310         free_irq_by_fd(chan->fd);
 311         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 312         kfree(chan);
 313 }
 314
 315 void free_chan(struct list_head *chans)
 316 {
 317         struct list_head *ele, *next;
 318         struct chan *chan;
 319
 320         list_for_each_safe(ele, next, chans){
 321                 chan = list_entry(ele, struct chan, list);
 322                 free_one_chan(chan);
 323         }
 324 }
 325
 326 static int one_chan_config_string(struct chan *chan, char *str, int size,
 327                                   char **error_out)
 328 {
 329         int n = 0;
 330
 331         if(chan == NULL){
 332                 CONFIG_CHUNK(str, size, n, "none", 1);
 333                 return(n);
 334         }
 335
 336         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 337
 338         if(chan->dev == NULL){
 339                 CONFIG_CHUNK(str, size, n, "", 1);
 340                 return(n);
 341         }
 342
 343         CONFIG_CHUNK(str, size, n, ":", 0);
 344         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 345
 346         return(n);
 347 }
 348
 349 static int chan_pair_config_string(struct chan *in, struct chan *out,
 350                                    char *str, int size, char **error_out)
 351 {
 352         int n;
 353
 354         n = one_chan_config_string(in, str, size, error_out);
 355         str += n;
 356         size -= n;
 357
 358         if(in == out){
 359                 CONFIG_CHUNK(str, size, n, "", 1);
 360                 return(n);
 361         }
 362
 363         CONFIG_CHUNK(str, size, n, ",", 1);
 364         n = one_chan_config_string(out, str, size, error_out);
 365         str += n;
 366         size -= n;
 367         CONFIG_CHUNK(str, size, n, "", 1);
 368
 369         return(n);
 370 }
 371
 372 int chan_config_string(struct list_head *chans, char *str, int size,
 373                        char **error_out)
 374 {
 375         struct list_head *ele;
 376         struct chan *chan, *in = NULL, *out = NULL;
 377
 378         list_for_each(ele, chans){
 379                 chan = list_entry(ele, struct chan, list);
 380                 if(!chan->primary)
 381                         continue;
 382                 if(chan->input)
 383                         in = chan;
 384                 if(chan->output)
 385                         out = chan;
 386         }
 387
 388         return(chan_pair_config_string(in, out, str, size, error_out));
 389 }
 390
 391 struct chan_type {
 392         char *key;
 393         struct chan_ops *ops;
 394 };
 395
 396 struct chan_type chan_table[] = {
 397         { "fd", &fd_ops },
 398
 399 #ifdef CONFIG_NULL_CHAN
 400         { "null", &null_ops },
 401 #else
 402         { "null", &not_configged_ops },
 403 #endif
 404
 405 #ifdef CONFIG_PORT_CHAN
 406         { "port", &port_ops },
 407 #else
 408         { "port", &not_configged_ops },
 409 #endif
 410
 411 #ifdef CONFIG_PTY_CHAN
 412         { "pty", &pty_ops },
 413         { "pts", &pts_ops },
 414 #else
 415         { "pty", &not_configged_ops },
 416         { "pts", &not_configged_ops },
 417 #endif
 418
 419 #ifdef CONFIG_TTY_CHAN
 420         { "tty", &tty_ops },
 421 #else
 422         { "tty", &not_configged_ops },
 423 #endif
 424
 425 #ifdef CONFIG_XTERM_CHAN
 426         { "xterm", &xterm_ops },
 427 #else
 428         { "xterm", &not_configged_ops },
 429 #endif
 430 };
 431
 432 static struct chan *parse_chan(char *str, int pri, int device,
 433                                struct chan_opts *opts)
 434 {
 435         struct chan_type *entry;
 436         struct chan_ops *ops;
 437         struct chan *chan;
 438         void *data;
 439         int i;
 440
 441         ops = NULL;
 442         data = NULL;
 443         for(i = 0; i < sizeof(chan_table)/sizeof(chan_table[0]); i++){
 444                 entry = &chan_table[i];
 445                 if(!strncmp(str, entry->key, strlen(entry->key))){
 446                         ops = entry->ops;
 447                         str += strlen(entry->key);
 448                         break;
 449                 }
 450         }
 451         if(ops == NULL){
 452                 printk(KERN_ERR "parse_chan couldn't parse \"%s\"\n",
 453                        str);
 454                 return(NULL);
 455         }
 456         if(ops->init == NULL) return(NULL);
 457         data = (*ops->init)(str, device, opts);
 458         if(data == NULL) return(NULL);
 459
 460         chan = kmalloc(sizeof(*chan), GFP_KERNEL);
 461         if(chan == NULL) return(NULL);
 462         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 463                                  .primary       = 1,
 464                                  .input         = 0,
 465                                  .output        = 0,
 466                                  .opened        = 0,
 467                                  .fd            = -1,
 468                                  .pri           = pri,
 469                                  .ops           = ops,
 470                                  .data          = data });
 471         return(chan);
 472 }
 473
 474 int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
 475                     struct chan_opts *opts)
 476 {
 477         struct chan *new, *chan;
 478         char *in, *out;
 479
 480         if(!list_empty(chans)){
 481                 chan = list_entry(chans->next, struct chan, list);
 482                 if(chan->pri >= pri) return(0);
 483                 free_chan(chans);
 484                 INIT_LIST_HEAD(chans);
 485         }
 486
 487         out = strchr(str, ',');
 488         if(out != NULL){
 489                 in = str;
 490                 *out = '\0';
 491                 out++;
 492                 new = parse_chan(in, pri, device, opts);
 493                 if(new == NULL) return(-1);
 494                 new->input = 1;
 495                 list_add(&new->list, chans);
 496
 497                 new = parse_chan(out, pri, device, opts);
 498                 if(new == NULL) return(-1);
 499                 list_add(&new->list, chans);
 500                 new->output = 1;
 501         }
 502         else {
 503                 new = parse_chan(str, pri, device, opts);
 504                 if(new == NULL) return(-1);
 505                 list_add(&new->list, chans);
 506                 new->input = 1;
 507                 new->output = 1;
 508         }
 509         return(0);
 510 }
 511
 512 int chan_out_fd(struct list_head *chans)
 513 {
 514         struct list_head *ele;
 515         struct chan *chan;
 516
 517         list_for_each(ele, chans){
 518                 chan = list_entry(ele, struct chan, list);
 519                 if(chan->primary && chan->output)
 520                         return(chan->fd);
 521         }
 522         return(-1);
 523 }
 524
 525 void chan_interrupt(struct list_head *chans, struct work_struct *task,
 526                     struct tty_struct *tty, int irq)
 527 {
 528         struct list_head *ele, *next;
 529         struct chan *chan;
 530         int err;
 531         char c;
 532
 533         list_for_each_safe(ele, next, chans){
 534                 chan = list_entry(ele, struct chan, list);
 535                 if(!chan->input || (chan->ops->read == NULL)) continue;
 536                 do {
 537                         if((tty != NULL) &&
 538                            (tty->flip.count >= TTY_FLIPBUF_SIZE)){
 539                                 schedule_work(task);
 540                                 goto out;
 541                         }
 542                         err = chan->ops->read(chan->fd, &c, chan->data);
 543                         if(err > 0)
 544                                 tty_receive_char(tty, c);
 545                 } while(err > 0);
 546
 547                 if(err == 0) reactivate_fd(chan->fd, irq);
 548                 if(err == -EIO){
 549                         if(chan->primary){
 550                                 if(tty != NULL)
 551                                         tty_hangup(tty);
 552                                 line_disable(tty, irq);
 553                                 close_chan(chans);
 554                                 free_chan(chans);
 555                                 return;
 556                         }
 557                         else {
 558                                 if(chan->ops->close != NULL)
 559                                         chan->ops->close(chan->fd, chan->data);
 560                                 free_one_chan(chan);
 561                         }
 562                 }
 563         }
 564  out:
 565         if(tty) tty_flip_buffer_push(tty);
 566 }
 567
 568 /*
 569  * Overrides for Emacs so that we follow Linus's tabbing style.
 570  * Emacs will notice this stuff at the end of the file and automatically
 571  * adjust the settings for this buffer only.  This must remain at the end
 572  * of the file.
 573  * ---------------------------------------------------------------------------
 574  * Local variables:
 575  * c-file-style: "linux"
 576  * End:
 577  */