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