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