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                                        void *data)
  94 {
  95         my_puts("Using a channel type which is configured out of "
  96                "UML\n");
  97         return(-EIO);
  98 }
  99
 100 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
 101                                      unsigned short *cols)
 102 {
 103         my_puts("Using a channel type which is configured out of "
 104                "UML\n");
 105         return(-ENODEV);
 106 }
 107
 108 static void not_configged_free(void *data)
 109 {
 110         my_puts("Using a channel type which is configured out of "
 111                "UML\n");
 112 }
 113
 114 static struct chan_ops not_configged_ops = {
 115         .init           = not_configged_init,
 116         .open           = not_configged_open,
 117         .close          = not_configged_close,
 118         .read           = not_configged_read,
 119         .write          = not_configged_write,
 120         .console_write  = not_configged_console_write,
 121         .window_size    = not_configged_window_size,
 122         .free           = not_configged_free,
 123         .winch          = 0,
 124 };
 125 #endif /* CONFIG_NOCONFIG_CHAN */
 126
 127 void generic_close(int fd, void *unused)
 128 {
 129         os_close_file(fd);
 130 }
 131
 132 int generic_read(int fd, char *c_out, void *unused)
 133 {
 134         int n;
 135
 136         n = os_read_file(fd, c_out, sizeof(*c_out));
 137
 138         if(n == -EAGAIN)
 139                 return(0);
 140         else if(n == 0)
 141                 return(-EIO);
 142         return(n);
 143 }
 144
 145 /* XXX Trivial wrapper around os_write_file */
 146
 147 int generic_write(int fd, const char *buf, int n, void *unused)
 148 {
 149         return(os_write_file(fd, buf, n));
 150 }
 151
 152 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 153                         unsigned short *cols_out)
 154 {
 155         int rows, cols;
 156         int ret;
 157
 158         ret = os_window_size(fd, &rows, &cols);
 159         if(ret < 0)
 160                 return(ret);
 161
 162         ret = ((*rows_out != rows) || (*cols_out != cols));
 163
 164         *rows_out = rows;
 165         *cols_out = cols;
 166
 167         return(ret);
 168 }
 169
 170 void generic_free(void *data)
 171 {
 172         kfree(data);
 173 }
 174
 175 static void tty_receive_char(struct tty_struct *tty, char ch)
 176 {
 177         if(tty == NULL) return;
 178
 179         if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
 180                 if(ch == STOP_CHAR(tty)){
 181                         stop_tty(tty);
 182                         return;
 183                 }
 184                 else if(ch == START_CHAR(tty)){
 185                         start_tty(tty);
 186                         return;
 187                 }
 188         }
 189
 190         if((tty->flip.flag_buf_ptr == NULL) ||
 191            (tty->flip.char_buf_ptr == NULL))
 192                 return;
 193         tty_insert_flip_char(tty, ch, TTY_NORMAL);
 194 }
 195
 196 static int open_one_chan(struct chan *chan, int input, int output, int primary)
 197 {
 198         int fd;
 199
 200         if(chan->opened) return(0);
 201         if(chan->ops->open == NULL) fd = 0;
 202         else fd = (*chan->ops->open)(input, output, primary, chan->data,
 203                                      &chan->dev);
 204         if(fd < 0) 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, chan->input, chan->output,
 220                                     chan->primary);
 221                 if(chan->primary) 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 list_head *chans, struct tty_struct *tty)
 241 {
 242         struct list_head *ele;
 243         struct chan *chan;
 244
 245         list_for_each(ele, chans){
 246                 chan = list_entry(ele, struct chan, list);
 247                 if(!chan->opened) continue;
 248
 249                 line_setup_irq(chan->fd, chan->input, chan->output, tty);
 250         }
 251 }
 252
 253 void close_chan(struct list_head *chans)
 254 {
 255         struct chan *chan;
 256
 257         /* Close in reverse order as open in case more than one of them
 258          * refers to the same device and they save and restore that device's
 259          * state.  Then, the first one opened will have the original state,
 260          * so it must be the last closed.
 261          */
 262         list_for_each_entry_reverse(chan, chans, list) {
 263                 if(!chan->opened) continue;
 264                 if(chan->ops->close != NULL)
 265                         (*chan->ops->close)(chan->fd, chan->data);
 266                 chan->opened = 0;
 267                 chan->fd = -1;
 268         }
 269 }
 270
 271 int write_chan(struct list_head *chans, const char *buf, int len,
 272                int write_irq)
 273 {
 274         struct list_head *ele;
 275         struct chan *chan = NULL;
 276         int n, ret = 0;
 277
 278         list_for_each(ele, chans) {
 279                 chan = list_entry(ele, struct chan, list);
 280                 if (!chan->output || (chan->ops->write == NULL))
 281                         continue;
 282                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 283                 if (chan->primary) {
 284                         ret = n;
 285                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 286                                 reactivate_fd(chan->fd, write_irq);
 287                 }
 288         }
 289         return(ret);
 290 }
 291
 292 int console_write_chan(struct list_head *chans, const char *buf, int len)
 293 {
 294         struct list_head *ele;
 295         struct chan *chan;
 296         int n, ret = 0;
 297
 298         list_for_each(ele, chans){
 299                 chan = list_entry(ele, struct chan, list);
 300                 if(!chan->output || (chan->ops->console_write == NULL))
 301                         continue;
 302                 n = chan->ops->console_write(chan->fd, buf, len, chan->data);
 303                 if(chan->primary) ret = n;
 304         }
 305         return(ret);
 306 }
 307
 308 int console_open_chan(struct line *line, struct console *co, struct chan_opts *opts)
 309 {
 310         if (!list_empty(&line->chan_list))
 311                 return 0;
 312
 313         if (0 != parse_chan_pair(line->init_str, &line->chan_list,
 314                                  line->init_pri, co->index, opts))
 315                 return -1;
 316         if (0 != open_chan(&line->chan_list))
 317                 return -1;
 318         printk("Console initialized on /dev/%s%d\n",co->name,co->index);
 319         return 0;
 320 }
 321
 322 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 323                       unsigned short *cols_out)
 324 {
 325         struct list_head *ele;
 326         struct chan *chan;
 327
 328         list_for_each(ele, chans){
 329                 chan = list_entry(ele, struct chan, list);
 330                 if(chan->primary){
 331                         if(chan->ops->window_size == NULL) return(0);
 332                         return(chan->ops->window_size(chan->fd, chan->data,
 333                                                       rows_out, cols_out));
 334                 }
 335         }
 336         return(0);
 337 }
 338
 339 void free_one_chan(struct chan *chan)
 340 {
 341         list_del(&chan->list);
 342         if(chan->ops->free != NULL)
 343                 (*chan->ops->free)(chan->data);
 344         free_irq_by_fd(chan->fd);
 345         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 346         kfree(chan);
 347 }
 348
 349 void free_chan(struct list_head *chans)
 350 {
 351         struct list_head *ele, *next;
 352         struct chan *chan;
 353
 354         list_for_each_safe(ele, next, chans){
 355                 chan = list_entry(ele, struct chan, list);
 356                 free_one_chan(chan);
 357         }
 358 }
 359
 360 static int one_chan_config_string(struct chan *chan, char *str, int size,
 361                                   char **error_out)
 362 {
 363         int n = 0;
 364
 365         if(chan == NULL){
 366                 CONFIG_CHUNK(str, size, n, "none", 1);
 367                 return(n);
 368         }
 369
 370         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 371
 372         if(chan->dev == NULL){
 373                 CONFIG_CHUNK(str, size, n, "", 1);
 374                 return(n);
 375         }
 376
 377         CONFIG_CHUNK(str, size, n, ":", 0);
 378         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 379
 380         return(n);
 381 }
 382
 383 static int chan_pair_config_string(struct chan *in, struct chan *out,
 384                                    char *str, int size, char **error_out)
 385 {
 386         int n;
 387
 388         n = one_chan_config_string(in, str, size, error_out);
 389         str += n;
 390         size -= n;
 391
 392         if(in == out){
 393                 CONFIG_CHUNK(str, size, n, "", 1);
 394                 return(n);
 395         }
 396
 397         CONFIG_CHUNK(str, size, n, ",", 1);
 398         n = one_chan_config_string(out, str, size, error_out);
 399         str += n;
 400         size -= n;
 401         CONFIG_CHUNK(str, size, n, "", 1);
 402
 403         return(n);
 404 }
 405
 406 int chan_config_string(struct list_head *chans, char *str, int size,
 407                        char **error_out)
 408 {
 409         struct list_head *ele;
 410         struct chan *chan, *in = NULL, *out = NULL;
 411
 412         list_for_each(ele, chans){
 413                 chan = list_entry(ele, struct chan, list);
 414                 if(!chan->primary)
 415                         continue;
 416                 if(chan->input)
 417                         in = chan;
 418                 if(chan->output)
 419                         out = chan;
 420         }
 421
 422         return(chan_pair_config_string(in, out, str, size, error_out));
 423 }
 424
 425 struct chan_type {
 426         char *key;
 427         struct chan_ops *ops;
 428 };
 429
 430 struct chan_type chan_table[] = {
 431         { "fd", &fd_ops },
 432
 433 #ifdef CONFIG_NULL_CHAN
 434         { "null", &null_ops },
 435 #else
 436         { "null", &not_configged_ops },
 437 #endif
 438
 439 #ifdef CONFIG_PORT_CHAN
 440         { "port", &port_ops },
 441 #else
 442         { "port", &not_configged_ops },
 443 #endif
 444
 445 #ifdef CONFIG_PTY_CHAN
 446         { "pty", &pty_ops },
 447         { "pts", &pts_ops },
 448 #else
 449         { "pty", &not_configged_ops },
 450         { "pts", &not_configged_ops },
 451 #endif
 452
 453 #ifdef CONFIG_TTY_CHAN
 454         { "tty", &tty_ops },
 455 #else
 456         { "tty", &not_configged_ops },
 457 #endif
 458
 459 #ifdef CONFIG_XTERM_CHAN
 460         { "xterm", &xterm_ops },
 461 #else
 462         { "xterm", &not_configged_ops },
 463 #endif
 464 };
 465
 466 static struct chan *parse_chan(char *str, int pri, int device,
 467                                struct chan_opts *opts)
 468 {
 469         struct chan_type *entry;
 470         struct chan_ops *ops;
 471         struct chan *chan;
 472         void *data;
 473         int i;
 474
 475         ops = NULL;
 476         data = NULL;
 477         for(i = 0; i < sizeof(chan_table)/sizeof(chan_table[0]); i++){
 478                 entry = &chan_table[i];
 479                 if(!strncmp(str, entry->key, strlen(entry->key))){
 480                         ops = entry->ops;
 481                         str += strlen(entry->key);
 482                         break;
 483                 }
 484         }
 485         if(ops == NULL){
 486                 my_printf("parse_chan couldn't parse \"%s\"\n",
 487                        str);
 488                 return(NULL);
 489         }
 490         if(ops->init == NULL) return(NULL);
 491         data = (*ops->init)(str, device, opts);
 492         if(data == NULL) return(NULL);
 493
 494         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 495         if(chan == NULL) return(NULL);
 496         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 497                                  .primary       = 1,
 498                                  .input         = 0,
 499                                  .output        = 0,
 500                                  .opened        = 0,
 501                                  .fd            = -1,
 502                                  .pri           = pri,
 503                                  .ops           = ops,
 504                                  .data          = data });
 505         return(chan);
 506 }
 507
 508 int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
 509                     struct chan_opts *opts)
 510 {
 511         struct chan *new, *chan;
 512         char *in, *out;
 513
 514         if(!list_empty(chans)){
 515                 chan = list_entry(chans->next, struct chan, list);
 516                 if(chan->pri >= pri) return(0);
 517                 free_chan(chans);
 518                 INIT_LIST_HEAD(chans);
 519         }
 520
 521         out = strchr(str, ',');
 522         if(out != NULL){
 523                 in = str;
 524                 *out = '\0';
 525                 out++;
 526                 new = parse_chan(in, pri, device, opts);
 527                 if(new == NULL) return(-1);
 528                 new->input = 1;
 529                 list_add(&new->list, chans);
 530
 531                 new = parse_chan(out, pri, device, opts);
 532                 if(new == NULL) return(-1);
 533                 list_add(&new->list, chans);
 534                 new->output = 1;
 535         }
 536         else {
 537                 new = parse_chan(str, pri, device, opts);
 538                 if(new == NULL) return(-1);
 539                 list_add(&new->list, chans);
 540                 new->input = 1;
 541                 new->output = 1;
 542         }
 543         return(0);
 544 }
 545
 546 int chan_out_fd(struct list_head *chans)
 547 {
 548         struct list_head *ele;
 549         struct chan *chan;
 550
 551         list_for_each(ele, chans){
 552                 chan = list_entry(ele, struct chan, list);
 553                 if(chan->primary && chan->output)
 554                         return(chan->fd);
 555         }
 556         return(-1);
 557 }
 558
 559 void chan_interrupt(struct list_head *chans, struct work_struct *task,
 560                     struct tty_struct *tty, int irq)
 561 {
 562         struct list_head *ele, *next;
 563         struct chan *chan;
 564         int err;
 565         char c;
 566
 567         list_for_each_safe(ele, next, chans){
 568                 chan = list_entry(ele, struct chan, list);
 569                 if(!chan->input || (chan->ops->read == NULL)) continue;
 570                 do {
 571                         if((tty != NULL) &&
 572                            (tty->flip.count >= TTY_FLIPBUF_SIZE)){
 573                                 schedule_work(task);
 574                                 goto out;
 575                         }
 576                         err = chan->ops->read(chan->fd, &c, chan->data);
 577                         if(err > 0)
 578                                 tty_receive_char(tty, c);
 579                 } while(err > 0);
 580
 581                 if(err == 0) reactivate_fd(chan->fd, irq);
 582                 if(err == -EIO){
 583                         if(chan->primary){
 584                                 if(tty != NULL)
 585                                         tty_hangup(tty);
 586                                 line_disable(tty, irq);
 587                                 close_chan(chans);
 588                                 free_chan(chans);
 589                                 return;
 590                         }
 591                         else {
 592                                 if(chan->ops->close != NULL)
 593                                         chan->ops->close(chan->fd, chan->data);
 594                                 free_one_chan(chan);
 595                         }
 596                 }
 597         }
 598  out:
 599         if(tty) tty_flip_buffer_push(tty);
 600 }
 601
 602 /*
 603  * Overrides for Emacs so that we follow Linus's tabbing style.
 604  * Emacs will notice this stuff at the end of the file and automatically
 605  * adjust the settings for this buffer only.  This must remain at the end
 606  * of the file.
 607  * ---------------------------------------------------------------------------
 608  * Local variables:
 609  * c-file-style: "linux"
 610  * End:
 611  */