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 "kern.h"
  16 #include "irq_user.h"
  17 #include "sigio.h"
  18 #include "line.h"
  19 #include "os.h"
  20
  21 #ifdef CONFIG_NOCONFIG_CHAN
  22 static void *not_configged_init(char *str, int device,
  23                                 const struct chan_opts *opts)
  24 {
  25         printk("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("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("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("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("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 {
  60         printk("Using a channel type which is configured out of "
  61                "UML\n");
  62         return -EIO;
  63 }
  64
  65 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
  66                                      unsigned short *cols)
  67 {
  68         printk("Using a channel type which is configured out of "
  69                "UML\n");
  70         return -ENODEV;
  71 }
  72
  73 static void not_configged_free(void *data)
  74 {
  75         printk("Using a channel type which is configured out of "
  76                "UML\n");
  77 }
  78
  79 static const struct chan_ops not_configged_ops = {
  80         .init           = not_configged_init,
  81         .open           = not_configged_open,
  82         .close          = not_configged_close,
  83         .read           = not_configged_read,
  84         .write          = not_configged_write,
  85         .console_write  = not_configged_console_write,
  86         .window_size    = not_configged_window_size,
  87         .free           = not_configged_free,
  88         .winch          = 0,
  89 };
  90 #endif /* CONFIG_NOCONFIG_CHAN */
  91
  92 void generic_close(int fd, void *unused)
  93 {
  94         os_close_file(fd);
  95 }
  96
  97 int generic_read(int fd, char *c_out, void *unused)
  98 {
  99         int n;
 100
 101         n = os_read_file(fd, c_out, sizeof(*c_out));
 102
 103         if(n == -EAGAIN)
 104                 return 0;
 105         else if(n == 0)
 106                 return -EIO;
 107         return n;
 108 }
 109
 110 /* XXX Trivial wrapper around os_write_file */
 111
 112 int generic_write(int fd, const char *buf, int n, void *unused)
 113 {
 114         return os_write_file(fd, buf, n);
 115 }
 116
 117 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 118                         unsigned short *cols_out)
 119 {
 120         int rows, cols;
 121         int ret;
 122
 123         ret = os_window_size(fd, &rows, &cols);
 124         if(ret < 0)
 125                 return ret;
 126
 127         ret = ((*rows_out != rows) || (*cols_out != cols));
 128
 129         *rows_out = rows;
 130         *cols_out = cols;
 131
 132         return ret;
 133 }
 134
 135 void generic_free(void *data)
 136 {
 137         kfree(data);
 138 }
 139
 140 static void tty_receive_char(struct tty_struct *tty, char ch)
 141 {
 142         if(tty == NULL) return;
 143
 144         if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
 145                 if(ch == STOP_CHAR(tty)){
 146                         stop_tty(tty);
 147                         return;
 148                 }
 149                 else if(ch == START_CHAR(tty)){
 150                         start_tty(tty);
 151                         return;
 152                 }
 153         }
 154
 155         tty_insert_flip_char(tty, ch, TTY_NORMAL);
 156 }
 157
 158 static int open_one_chan(struct chan *chan)
 159 {
 160         int fd, err;
 161
 162         if(chan->opened)
 163                 return 0;
 164
 165         if(chan->ops->open == NULL)
 166                 fd = 0;
 167         else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
 168                                      chan->data, &chan->dev);
 169         if(fd < 0)
 170                 return fd;
 171
 172         err = os_set_fd_block(fd, 0);
 173         if (err) {
 174                 (*chan->ops->close)(fd, chan->data);
 175                 return err;
 176         }
 177
 178         chan->fd = fd;
 179
 180         chan->opened = 1;
 181         return 0;
 182 }
 183
 184 int open_chan(struct list_head *chans)
 185 {
 186         struct list_head *ele;
 187         struct chan *chan;
 188         int ret, err = 0;
 189
 190         list_for_each(ele, chans){
 191                 chan = list_entry(ele, struct chan, list);
 192                 ret = open_one_chan(chan);
 193                 if(chan->primary)
 194                         err = ret;
 195         }
 196         return err;
 197 }
 198
 199 void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
 200 {
 201         struct list_head *ele;
 202         struct chan *chan;
 203
 204         list_for_each(ele, chans){
 205                 chan = list_entry(ele, struct chan, list);
 206                 if(chan->primary && chan->output && chan->ops->winch){
 207                         register_winch(chan->fd, tty);
 208                         return;
 209                 }
 210         }
 211 }
 212
 213 int enable_chan(struct line *line)
 214 {
 215         struct list_head *ele;
 216         struct chan *chan;
 217         int err;
 218
 219         list_for_each(ele, &line->chan_list){
 220                 chan = list_entry(ele, struct chan, list);
 221                 err = open_one_chan(chan);
 222                 if (err) {
 223                         if (chan->primary)
 224                                 goto out_close;
 225
 226                         continue;
 227                 }
 228
 229                 if(chan->enabled)
 230                         continue;
 231                 err = line_setup_irq(chan->fd, chan->input, chan->output, line,
 232                                      chan);
 233                 if (err)
 234                         goto out_close;
 235
 236                 chan->enabled = 1;
 237         }
 238
 239         return 0;
 240
 241  out_close:
 242         close_chan(&line->chan_list, 0);
 243         return err;
 244 }
 245
 246 /* Items are added in IRQ context, when free_irq can't be called, and
 247  * removed in process context, when it can.
 248  * This handles interrupt sources which disappear, and which need to
 249  * be permanently disabled.  This is discovered in IRQ context, but
 250  * the freeing of the IRQ must be done later.
 251  */
 252 static DEFINE_SPINLOCK(irqs_to_free_lock);
 253 static LIST_HEAD(irqs_to_free);
 254
 255 void free_irqs(void)
 256 {
 257         struct chan *chan;
 258         LIST_HEAD(list);
 259         struct list_head *ele;
 260         unsigned long flags;
 261
 262         spin_lock_irqsave(&irqs_to_free_lock, flags);
 263         list_splice_init(&irqs_to_free, &list);
 264         spin_unlock_irqrestore(&irqs_to_free_lock, flags);
 265
 266         list_for_each(ele, &list){
 267                 chan = list_entry(ele, struct chan, free_list);
 268
 269                 if(chan->input)
 270                         free_irq(chan->line->driver->read_irq, chan);
 271                 if(chan->output)
 272                         free_irq(chan->line->driver->write_irq, chan);
 273                 chan->enabled = 0;
 274         }
 275 }
 276
 277 static void close_one_chan(struct chan *chan, int delay_free_irq)
 278 {
 279         unsigned long flags;
 280
 281         if(!chan->opened)
 282                 return;
 283
 284         if(delay_free_irq){
 285                 spin_lock_irqsave(&irqs_to_free_lock, flags);
 286                 list_add(&chan->free_list, &irqs_to_free);
 287                 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
 288         }
 289         else {
 290                 if(chan->input)
 291                         free_irq(chan->line->driver->read_irq, chan);
 292                 if(chan->output)
 293                         free_irq(chan->line->driver->write_irq, chan);
 294                 chan->enabled = 0;
 295         }
 296         if(chan->ops->close != NULL)
 297                 (*chan->ops->close)(chan->fd, chan->data);
 298
 299         chan->opened = 0;
 300         chan->fd = -1;
 301 }
 302
 303 void close_chan(struct list_head *chans, int delay_free_irq)
 304 {
 305         struct chan *chan;
 306
 307         /* Close in reverse order as open in case more than one of them
 308          * refers to the same device and they save and restore that device's
 309          * state.  Then, the first one opened will have the original state,
 310          * so it must be the last closed.
 311          */
 312         list_for_each_entry_reverse(chan, chans, list) {
 313                 close_one_chan(chan, delay_free_irq);
 314         }
 315 }
 316
 317 void deactivate_chan(struct list_head *chans, int irq)
 318 {
 319         struct list_head *ele;
 320
 321         struct chan *chan;
 322         list_for_each(ele, chans) {
 323                 chan = list_entry(ele, struct chan, list);
 324
 325                 if(chan->enabled && chan->input)
 326                         deactivate_fd(chan->fd, irq);
 327         }
 328 }
 329
 330 void reactivate_chan(struct list_head *chans, int irq)
 331 {
 332         struct list_head *ele;
 333         struct chan *chan;
 334
 335         list_for_each(ele, chans) {
 336                 chan = list_entry(ele, struct chan, list);
 337
 338                 if(chan->enabled && chan->input)
 339                         reactivate_fd(chan->fd, irq);
 340         }
 341 }
 342
 343 int write_chan(struct list_head *chans, const char *buf, int len,
 344                int write_irq)
 345 {
 346         struct list_head *ele;
 347         struct chan *chan = NULL;
 348         int n, ret = 0;
 349
 350         list_for_each(ele, chans) {
 351                 chan = list_entry(ele, struct chan, list);
 352                 if (!chan->output || (chan->ops->write == NULL))
 353                         continue;
 354                 n = chan->ops->write(chan->fd, buf, len, chan->data);
 355                 if (chan->primary) {
 356                         ret = n;
 357                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 358                                 reactivate_fd(chan->fd, write_irq);
 359                 }
 360         }
 361         return ret;
 362 }
 363
 364 int console_write_chan(struct list_head *chans, const char *buf, int len)
 365 {
 366         struct list_head *ele;
 367         struct chan *chan;
 368         int n, ret = 0;
 369
 370         list_for_each(ele, chans){
 371                 chan = list_entry(ele, struct chan, list);
 372                 if(!chan->output || (chan->ops->console_write == NULL))
 373                         continue;
 374                 n = chan->ops->console_write(chan->fd, buf, len);
 375                 if(chan->primary) ret = n;
 376         }
 377         return ret;
 378 }
 379
 380 int console_open_chan(struct line *line, struct console *co)
 381 {
 382         int err;
 383
 384         err = open_chan(&line->chan_list);
 385         if(err)
 386                 return err;
 387
 388         printk("Console initialized on /dev/%s%d\n", co->name, co->index);
 389         return 0;
 390 }
 391
 392 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 393                       unsigned short *cols_out)
 394 {
 395         struct list_head *ele;
 396         struct chan *chan;
 397
 398         list_for_each(ele, chans){
 399                 chan = list_entry(ele, struct chan, list);
 400                 if(chan->primary){
 401                         if(chan->ops->window_size == NULL)
 402                                 return 0;
 403                         return chan->ops->window_size(chan->fd, chan->data,
 404                                                       rows_out, cols_out);
 405                 }
 406         }
 407         return 0;
 408 }
 409
 410 static void free_one_chan(struct chan *chan, int delay_free_irq)
 411 {
 412         list_del(&chan->list);
 413
 414         close_one_chan(chan, delay_free_irq);
 415
 416         if(chan->ops->free != NULL)
 417                 (*chan->ops->free)(chan->data);
 418
 419         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 420         kfree(chan);
 421 }
 422
 423 static void free_chan(struct list_head *chans, int delay_free_irq)
 424 {
 425         struct list_head *ele, *next;
 426         struct chan *chan;
 427
 428         list_for_each_safe(ele, next, chans){
 429                 chan = list_entry(ele, struct chan, list);
 430                 free_one_chan(chan, delay_free_irq);
 431         }
 432 }
 433
 434 static int one_chan_config_string(struct chan *chan, char *str, int size,
 435                                   char **error_out)
 436 {
 437         int n = 0;
 438
 439         if(chan == NULL){
 440                 CONFIG_CHUNK(str, size, n, "none", 1);
 441                 return n;
 442         }
 443
 444         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 445
 446         if(chan->dev == NULL){
 447                 CONFIG_CHUNK(str, size, n, "", 1);
 448                 return n;
 449         }
 450
 451         CONFIG_CHUNK(str, size, n, ":", 0);
 452         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 453
 454         return n;
 455 }
 456
 457 static int chan_pair_config_string(struct chan *in, struct chan *out,
 458                                    char *str, int size, char **error_out)
 459 {
 460         int n;
 461
 462         n = one_chan_config_string(in, str, size, error_out);
 463         str += n;
 464         size -= n;
 465
 466         if(in == out){
 467                 CONFIG_CHUNK(str, size, n, "", 1);
 468                 return n;
 469         }
 470
 471         CONFIG_CHUNK(str, size, n, ",", 1);
 472         n = one_chan_config_string(out, str, size, error_out);
 473         str += n;
 474         size -= n;
 475         CONFIG_CHUNK(str, size, n, "", 1);
 476
 477         return n;
 478 }
 479
 480 int chan_config_string(struct list_head *chans, char *str, int size,
 481                        char **error_out)
 482 {
 483         struct list_head *ele;
 484         struct chan *chan, *in = NULL, *out = NULL;
 485
 486         list_for_each(ele, chans){
 487                 chan = list_entry(ele, struct chan, list);
 488                 if(!chan->primary)
 489                         continue;
 490                 if(chan->input)
 491                         in = chan;
 492                 if(chan->output)
 493                         out = chan;
 494         }
 495
 496         return chan_pair_config_string(in, out, str, size, error_out);
 497 }
 498
 499 struct chan_type {
 500         char *key;
 501         const struct chan_ops *ops;
 502 };
 503
 504 static const struct chan_type chan_table[] = {
 505         { "fd", &fd_ops },
 506
 507 #ifdef CONFIG_NULL_CHAN
 508         { "null", &null_ops },
 509 #else
 510         { "null", &not_configged_ops },
 511 #endif
 512
 513 #ifdef CONFIG_PORT_CHAN
 514         { "port", &port_ops },
 515 #else
 516         { "port", &not_configged_ops },
 517 #endif
 518
 519 #ifdef CONFIG_PTY_CHAN
 520         { "pty", &pty_ops },
 521         { "pts", &pts_ops },
 522 #else
 523         { "pty", &not_configged_ops },
 524         { "pts", &not_configged_ops },
 525 #endif
 526
 527 #ifdef CONFIG_TTY_CHAN
 528         { "tty", &tty_ops },
 529 #else
 530         { "tty", &not_configged_ops },
 531 #endif
 532
 533 #ifdef CONFIG_XTERM_CHAN
 534         { "xterm", &xterm_ops },
 535 #else
 536         { "xterm", &not_configged_ops },
 537 #endif
 538 };
 539
 540 static struct chan *parse_chan(struct line *line, char *str, int device,
 541                                const struct chan_opts *opts, char **error_out)
 542 {
 543         const struct chan_type *entry;
 544         const struct chan_ops *ops;
 545         struct chan *chan;
 546         void *data;
 547         int i;
 548
 549         ops = NULL;
 550         data = NULL;
 551         for(i = 0; i < ARRAY_SIZE(chan_table); i++){
 552                 entry = &chan_table[i];
 553                 if(!strncmp(str, entry->key, strlen(entry->key))){
 554                         ops = entry->ops;
 555                         str += strlen(entry->key);
 556                         break;
 557                 }
 558         }
 559         if(ops == NULL){
 560                 *error_out = "No match for configured backends";
 561                 return NULL;
 562         }
 563
 564         data = (*ops->init)(str, device, opts);
 565         if(data == NULL){
 566                 *error_out = "Configuration failed";
 567                 return NULL;
 568         }
 569
 570         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 571         if(chan == NULL){
 572                 *error_out = "Memory allocation failed";
 573                 return NULL;
 574         }
 575         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 576                                  .free_list     =
 577                                         LIST_HEAD_INIT(chan->free_list),
 578                                  .line          = line,
 579                                  .primary       = 1,
 580                                  .input         = 0,
 581                                  .output        = 0,
 582                                  .opened        = 0,
 583                                  .enabled       = 0,
 584                                  .fd            = -1,
 585                                  .ops           = ops,
 586                                  .data          = data });
 587         return chan;
 588 }
 589
 590 int parse_chan_pair(char *str, struct line *line, int device,
 591                     const struct chan_opts *opts, char **error_out)
 592 {
 593         struct list_head *chans = &line->chan_list;
 594         struct chan *new, *chan;
 595         char *in, *out;
 596
 597         if(!list_empty(chans)){
 598                 chan = list_entry(chans->next, struct chan, list);
 599                 free_chan(chans, 0);
 600                 INIT_LIST_HEAD(chans);
 601         }
 602
 603         out = strchr(str, ',');
 604         if(out != NULL){
 605                 in = str;
 606                 *out = '\0';
 607                 out++;
 608                 new = parse_chan(line, in, device, opts, error_out);
 609                 if(new == NULL)
 610                         return -1;
 611
 612                 new->input = 1;
 613                 list_add(&new->list, chans);
 614
 615                 new = parse_chan(line, out, device, opts, error_out);
 616                 if(new == NULL)
 617                         return -1;
 618
 619                 list_add(&new->list, chans);
 620                 new->output = 1;
 621         }
 622         else {
 623                 new = parse_chan(line, str, device, opts, error_out);
 624                 if(new == NULL)
 625                         return -1;
 626
 627                 list_add(&new->list, chans);
 628                 new->input = 1;
 629                 new->output = 1;
 630         }
 631         return 0;
 632 }
 633
 634 int chan_out_fd(struct list_head *chans)
 635 {
 636         struct list_head *ele;
 637         struct chan *chan;
 638
 639         list_for_each(ele, chans){
 640                 chan = list_entry(ele, struct chan, list);
 641                 if(chan->primary && chan->output)
 642                         return chan->fd;
 643         }
 644         return -1;
 645 }
 646
 647 void chan_interrupt(struct list_head *chans, struct delayed_work *task,
 648                     struct tty_struct *tty, int irq)
 649 {
 650         struct list_head *ele, *next;
 651         struct chan *chan;
 652         int err;
 653         char c;
 654
 655         list_for_each_safe(ele, next, chans){
 656                 chan = list_entry(ele, struct chan, list);
 657                 if(!chan->input || (chan->ops->read == NULL)) continue;
 658                 do {
 659                         if (tty && !tty_buffer_request_room(tty, 1)) {
 660                                 schedule_delayed_work(task, 1);
 661                                 goto out;
 662                         }
 663                         err = chan->ops->read(chan->fd, &c, chan->data);
 664                         if(err > 0)
 665                                 tty_receive_char(tty, c);
 666                 } while(err > 0);
 667
 668                 if(err == 0) reactivate_fd(chan->fd, irq);
 669                 if(err == -EIO){
 670                         if(chan->primary){
 671                                 if(tty != NULL)
 672                                         tty_hangup(tty);
 673                                 close_chan(chans, 1);
 674                                 return;
 675                         }
 676                         else close_one_chan(chan, 1);
 677                 }
 678         }
 679  out:
 680         if(tty) tty_flip_buffer_push(tty);
 681 }