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
  24 /* The printk's here are wrong because we are complaining that there is no
  25  * output device, but printk is printing to that output device.  The user will
  26  * never see the error.  printf would be better, except it can't run on a
  27  * kernel stack because it will overflow it.
  28  * Use printk for now since that will avoid crashing.
  29  */
  30
  31 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
  32 {
  33         printk(KERN_ERR "Using a channel type which is configured out of "
  34                "UML\n");
  35         return(NULL);
  36 }
  37
  38 static int not_configged_open(int input, int output, int primary, void *data,
  39                               char **dev_out)
  40 {
  41         printk(KERN_ERR "Using a channel type which is configured out of "
  42                "UML\n");
  43         return(-ENODEV);
  44 }
  45
  46 static void not_configged_close(int fd, void *data)
  47 {
  48         printk(KERN_ERR "Using a channel type which is configured out of "
  49                "UML\n");
  50 }
  51
  52 static int not_configged_read(int fd, char *c_out, void *data)
  53 {
  54         printk(KERN_ERR "Using a channel type which is configured out of "
  55                "UML\n");
  56         return(-EIO);
  57 }
  58
  59 static int not_configged_write(int fd, const char *buf, int len, 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_console_write(int fd, const char *buf, int len,
  67                                        void *data)
  68 {
  69         printk(KERN_ERR "Using a channel type which is configured out of "
  70                "UML\n");
  71         return(-EIO);
  72 }
  73
  74 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
  75                                      unsigned short *cols)
  76 {
  77         printk(KERN_ERR "Using a channel type which is configured out of "
  78                "UML\n");
  79         return(-ENODEV);
  80 }
  81
  82 static void not_configged_free(void *data)
  83 {
  84         printf(KERN_ERR "Using a channel type which is configured out of "
  85                "UML\n");
  86 }
  87
  88 static struct chan_ops not_configged_ops = {
  89         .init           = not_configged_init,
  90         .open           = not_configged_open,
  91         .close          = not_configged_close,
  92         .read           = not_configged_read,
  93         .write          = not_configged_write,
  94         .console_write  = not_configged_console_write,
  95         .window_size    = not_configged_window_size,
  96         .free           = not_configged_free,
  97         .winch          = 0,
  98 };
  99 #endif /* CONFIG_NOCONFIG_CHAN */
 100
 101 void generic_close(int fd, void *unused)
 102 {
 103         os_close_file(fd);
 104 }
 105
 106 int generic_read(int fd, char *c_out, void *unused)
 107 {
 108         int n;
 109
 110         n = os_read_file(fd, c_out, sizeof(*c_out));
 111
 112         if(n == -EAGAIN)
 113                 return(0);
 114         else if(n == 0)
 115                 return(-EIO);
 116         return(n);
 117 }
 118
 119 /* XXX Trivial wrapper around os_write_file */
 120
 121 int generic_write(int fd, const char *buf, int n, void *unused)
 122 {
 123         return(os_write_file(fd, buf, n));
 124 }
 125
 126 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 127                         unsigned short *cols_out)
 128 {
 129         int rows, cols;
 130         int ret;
 131
 132         ret = os_window_size(fd, &rows, &cols);
 133         if(ret < 0)
 134                 return(ret);
 135
 136         ret = ((*rows_out != rows) || (*cols_out != cols));
 137
 138         *rows_out = rows;
 139         *cols_out = cols;
 140
 141         return(ret);
 142 }
 143
 144 void generic_free(void *data)
 145 {
 146         kfree(data);
 147 }
 148
 149 static void tty_receive_char(struct tty_struct *tty, char ch)
 150 {
 151         if(tty == NULL) return;
 152
 153         if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
 154                 if(ch == STOP_CHAR(tty)){
 155                         stop_tty(tty);
 156                         return;
 157                 }
 158                 else if(ch == START_CHAR(tty)){
 159                         start_tty(tty);
 160                         return;
 161                 }
 162         }
 163
 164         if((tty->flip.flag_buf_ptr == NULL) ||
 165            (tty->flip.char_buf_ptr == NULL))
 166                 return;
 167         tty_insert_flip_char(tty, ch, TTY_NORMAL);
 168 }
 169
 170 static int open_one_chan(struct chan *chan, int input, int output, int primary)
 171 {
 172         int fd;
 173
 174         if(chan->opened) return(0);
 175         if(chan->ops->open == NULL) fd = 0;
 176         else fd = (*chan->ops->open)(input, output, primary, chan->data,
 177                                      &chan->dev);
 178         if(fd < 0) return(fd);
 179         chan->fd = fd;
 180
 181         chan->opened = 1;
 182         return(0);
 183 }
 184
 185 int open_chan(struct list_head *chans)
 186 {
 187         struct list_head *ele;
 188         struct chan *chan;
 189         int ret, err = 0;
 190
 191         list_for_each(ele, chans){
 192                 chan = list_entry(ele, struct chan, list);
 193                 ret = open_one_chan(chan, chan->input, chan->output,
 194                                     chan->primary);
 195                 if(chan->primary) err = ret;
 196         }
 197         return(err);
 198 }
 199
 200 void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
 201 {
 202         struct list_head *ele;
 203         struct chan *chan;
 204
 205         list_for_each(ele, chans){
 206                 chan = list_entry(ele, struct chan, list);
 207                 if(chan->primary && chan->output && chan->ops->winch){
 208                         register_winch(chan->fd, tty);
 209                         return;
 210                 }
 211         }
 212 }
 213
 214 void enable_chan(struct list_head *chans, struct tty_struct *tty)
 215 {
 216         struct list_head *ele;
 217         struct chan *chan;
 218
 219         list_for_each(ele, chans){
 220                 chan = list_entry(ele, struct chan, list);
 221                 if(!chan->opened) continue;
 222
 223                 line_setup_irq(chan->fd, chan->input, chan->output, tty);
 224         }
 225 }
 226
 227 void close_chan(struct list_head *chans)
 228 {
 229         struct chan *chan;
 230
 231         /* Close in reverse order as open in case more than one of them
 232          * refers to the same device and they save and restore that device's
 233          * state.  Then, the first one opened will have the original state,
 234          * so it must be the last closed.
 235          */
 236         list_for_each_entry_reverse(chan, chans, list) {
 237                 if(!chan->opened) continue;
 238                 if(chan->ops->close != NULL)
 239                         (*chan->ops->close)(chan->fd, chan->data);
 240                 chan->opened = 0;
 241                 chan->fd = -1;
 242         }
 243 }
 244
 245 int write_chan(struct list_head *chans, const char *buf, int len,
 246                int write_irq)
 247 {
 248         struct list_head *ele;
 249         struct chan *chan = NULL;
 250         int n, ret = 0;
 251
 252         list_for_each(ele, chans) {
 253                 chan = list_entry(ele, struct chan, list);
 254                 if (!chan->output || (chan->ops->write == NULL))
 255                         continue;
 256                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 257                 if (chan->primary) {
 258                         ret = n;
 259                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 260                                 reactivate_fd(chan->fd, write_irq);
 261                 }
 262         }
 263         return(ret);
 264 }
 265
 266 int console_write_chan(struct list_head *chans, const char *buf, int len)
 267 {
 268         struct list_head *ele;
 269         struct chan *chan;
 270         int n, ret = 0;
 271
 272         list_for_each(ele, chans){
 273                 chan = list_entry(ele, struct chan, list);
 274                 if(!chan->output || (chan->ops->console_write == NULL))
 275                         continue;
 276                 n = chan->ops->console_write(chan->fd, buf, len, chan->data);
 277                 if(chan->primary) ret = n;
 278         }
 279         return(ret);
 280 }
 281
 282 int console_open_chan(struct line *line, struct console *co, struct chan_opts *opts)
 283 {
 284         if (!list_empty(&line->chan_list))
 285                 return 0;
 286
 287         if (0 != parse_chan_pair(line->init_str, &line->chan_list,
 288                                  line->init_pri, co->index, opts))
 289                 return -1;
 290         if (0 != open_chan(&line->chan_list))
 291                 return -1;
 292         printk("Console initialized on /dev/%s%d\n",co->name,co->index);
 293         return 0;
 294 }
 295
 296 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 297                       unsigned short *cols_out)
 298 {
 299         struct list_head *ele;
 300         struct chan *chan;
 301
 302         list_for_each(ele, chans){
 303                 chan = list_entry(ele, struct chan, list);
 304                 if(chan->primary){
 305                         if(chan->ops->window_size == NULL) return(0);
 306                         return(chan->ops->window_size(chan->fd, chan->data,
 307                                                       rows_out, cols_out));
 308                 }
 309         }
 310         return(0);
 311 }
 312
 313 void free_one_chan(struct chan *chan)
 314 {
 315         list_del(&chan->list);
 316         if(chan->ops->free != NULL)
 317                 (*chan->ops->free)(chan->data);
 318         free_irq_by_fd(chan->fd);
 319         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 320         kfree(chan);
 321 }
 322
 323 void free_chan(struct list_head *chans)
 324 {
 325         struct list_head *ele, *next;
 326         struct chan *chan;
 327
 328         list_for_each_safe(ele, next, chans){
 329                 chan = list_entry(ele, struct chan, list);
 330                 free_one_chan(chan);
 331         }
 332 }
 333
 334 static int one_chan_config_string(struct chan *chan, char *str, int size,
 335                                   char **error_out)
 336 {
 337         int n = 0;
 338
 339         if(chan == NULL){
 340                 CONFIG_CHUNK(str, size, n, "none", 1);
 341                 return(n);
 342         }
 343
 344         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 345
 346         if(chan->dev == NULL){
 347                 CONFIG_CHUNK(str, size, n, "", 1);
 348                 return(n);
 349         }
 350
 351         CONFIG_CHUNK(str, size, n, ":", 0);
 352         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 353
 354         return(n);
 355 }
 356
 357 static int chan_pair_config_string(struct chan *in, struct chan *out,
 358                                    char *str, int size, char **error_out)
 359 {
 360         int n;
 361
 362         n = one_chan_config_string(in, str, size, error_out);
 363         str += n;
 364         size -= n;
 365
 366         if(in == out){
 367                 CONFIG_CHUNK(str, size, n, "", 1);
 368                 return(n);
 369         }
 370
 371         CONFIG_CHUNK(str, size, n, ",", 1);
 372         n = one_chan_config_string(out, str, size, error_out);
 373         str += n;
 374         size -= n;
 375         CONFIG_CHUNK(str, size, n, "", 1);
 376
 377         return(n);
 378 }
 379
 380 int chan_config_string(struct list_head *chans, char *str, int size,
 381                        char **error_out)
 382 {
 383         struct list_head *ele;
 384         struct chan *chan, *in = NULL, *out = NULL;
 385
 386         list_for_each(ele, chans){
 387                 chan = list_entry(ele, struct chan, list);
 388                 if(!chan->primary)
 389                         continue;
 390                 if(chan->input)
 391                         in = chan;
 392                 if(chan->output)
 393                         out = chan;
 394         }
 395
 396         return(chan_pair_config_string(in, out, str, size, error_out));
 397 }
 398
 399 struct chan_type {
 400         char *key;
 401         struct chan_ops *ops;
 402 };
 403
 404 struct chan_type chan_table[] = {
 405         { "fd", &fd_ops },
 406
 407 #ifdef CONFIG_NULL_CHAN
 408         { "null", &null_ops },
 409 #else
 410         { "null", &not_configged_ops },
 411 #endif
 412
 413 #ifdef CONFIG_PORT_CHAN
 414         { "port", &port_ops },
 415 #else
 416         { "port", &not_configged_ops },
 417 #endif
 418
 419 #ifdef CONFIG_PTY_CHAN
 420         { "pty", &pty_ops },
 421         { "pts", &pts_ops },
 422 #else
 423         { "pty", &not_configged_ops },
 424         { "pts", &not_configged_ops },
 425 #endif
 426
 427 #ifdef CONFIG_TTY_CHAN
 428         { "tty", &tty_ops },
 429 #else
 430         { "tty", &not_configged_ops },
 431 #endif
 432
 433 #ifdef CONFIG_XTERM_CHAN
 434         { "xterm", &xterm_ops },
 435 #else
 436         { "xterm", &not_configged_ops },
 437 #endif
 438 };
 439
 440 static struct chan *parse_chan(char *str, int pri, int device,
 441                                struct chan_opts *opts)
 442 {
 443         struct chan_type *entry;
 444         struct chan_ops *ops;
 445         struct chan *chan;
 446         void *data;
 447         int i;
 448
 449         ops = NULL;
 450         data = NULL;
 451         for(i = 0; i < sizeof(chan_table)/sizeof(chan_table[0]); i++){
 452                 entry = &chan_table[i];
 453                 if(!strncmp(str, entry->key, strlen(entry->key))){
 454                         ops = entry->ops;
 455                         str += strlen(entry->key);
 456                         break;
 457                 }
 458         }
 459         if(ops == NULL){
 460                 printk(KERN_ERR "parse_chan couldn't parse \"%s\"\n",
 461                        str);
 462                 return(NULL);
 463         }
 464         if(ops->init == NULL) return(NULL);
 465         data = (*ops->init)(str, device, opts);
 466         if(data == NULL) return(NULL);
 467
 468         chan = kmalloc(sizeof(*chan), GFP_KERNEL);
 469         if(chan == NULL) return(NULL);
 470         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 471                                  .primary       = 1,
 472                                  .input         = 0,
 473                                  .output        = 0,
 474                                  .opened        = 0,
 475                                  .fd            = -1,
 476                                  .pri           = pri,
 477                                  .ops           = ops,
 478                                  .data          = data });
 479         return(chan);
 480 }
 481
 482 int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
 483                     struct chan_opts *opts)
 484 {
 485         struct chan *new, *chan;
 486         char *in, *out;
 487
 488         if(!list_empty(chans)){
 489                 chan = list_entry(chans->next, struct chan, list);
 490                 if(chan->pri >= pri) return(0);
 491                 free_chan(chans);
 492                 INIT_LIST_HEAD(chans);
 493         }
 494
 495         out = strchr(str, ',');
 496         if(out != NULL){
 497                 in = str;
 498                 *out = '\0';
 499                 out++;
 500                 new = parse_chan(in, pri, device, opts);
 501                 if(new == NULL) return(-1);
 502                 new->input = 1;
 503                 list_add(&new->list, chans);
 504
 505                 new = parse_chan(out, pri, device, opts);
 506                 if(new == NULL) return(-1);
 507                 list_add(&new->list, chans);
 508                 new->output = 1;
 509         }
 510         else {
 511                 new = parse_chan(str, pri, device, opts);
 512                 if(new == NULL) return(-1);
 513                 list_add(&new->list, chans);
 514                 new->input = 1;
 515                 new->output = 1;
 516         }
 517         return(0);
 518 }
 519
 520 int chan_out_fd(struct list_head *chans)
 521 {
 522         struct list_head *ele;
 523         struct chan *chan;
 524
 525         list_for_each(ele, chans){
 526                 chan = list_entry(ele, struct chan, list);
 527                 if(chan->primary && chan->output)
 528                         return(chan->fd);
 529         }
 530         return(-1);
 531 }
 532
 533 void chan_interrupt(struct list_head *chans, struct work_struct *task,
 534                     struct tty_struct *tty, int irq)
 535 {
 536         struct list_head *ele, *next;
 537         struct chan *chan;
 538         int err;
 539         char c;
 540
 541         list_for_each_safe(ele, next, chans){
 542                 chan = list_entry(ele, struct chan, list);
 543                 if(!chan->input || (chan->ops->read == NULL)) continue;
 544                 do {
 545                         if((tty != NULL) &&
 546                            (tty->flip.count >= TTY_FLIPBUF_SIZE)){
 547                                 schedule_work(task);
 548                                 goto out;
 549                         }
 550                         err = chan->ops->read(chan->fd, &c, chan->data);
 551                         if(err > 0)
 552                                 tty_receive_char(tty, c);
 553                 } while(err > 0);
 554
 555                 if(err == 0) reactivate_fd(chan->fd, irq);
 556                 if(err == -EIO){
 557                         if(chan->primary){
 558                                 if(tty != NULL)
 559                                         tty_hangup(tty);
 560                                 line_disable(tty, irq);
 561                                 close_chan(chans);
 562                                 free_chan(chans);
 563                                 return;
 564                         }
 565                         else {
 566                                 if(chan->ops->close != NULL)
 567                                         chan->ops->close(chan->fd, chan->data);
 568                                 free_one_chan(chan);
 569                         }
 570                 }
 571         }
 572  out:
 573         if(tty) tty_flip_buffer_push(tty);
 574 }
 575
 576 /*
 577  * Overrides for Emacs so that we follow Linus's tabbing style.
 578  * Emacs will notice this stuff at the end of the file and automatically
 579  * adjust the settings for this buffer only.  This must remain at the end
 580  * of the file.
 581  * ---------------------------------------------------------------------------
 582  * Local variables:
 583  * c-file-style: "linux"
 584  * End:
 585  */