arch/um/drivers/chan_kern.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <linux/slab.h>
   7 #include <linux/tty.h>
   8 #include <linux/tty_flip.h>
   9 #include "chan.h"
  10 #include <os.h>
  11 #include <irq_kern.h>
  12
  13 #ifdef CONFIG_NOCONFIG_CHAN
  14 static void *not_configged_init(char *str, int device,
  15                                 const struct chan_opts *opts)
  16 {
  17         printk(KERN_ERR "Using a channel type which is configured out of "
  18                "UML\n");
  19         return NULL;
  20 }
  21
  22 static int not_configged_open(int input, int output, int primary, void *data,
  23                               char **dev_out)
  24 {
  25         printk(KERN_ERR "Using a channel type which is configured out of "
  26                "UML\n");
  27         return -ENODEV;
  28 }
  29
  30 static void not_configged_close(int fd, void *data)
  31 {
  32         printk(KERN_ERR "Using a channel type which is configured out of "
  33                "UML\n");
  34 }
  35
  36 static int not_configged_read(int fd, char *c_out, void *data)
  37 {
  38         printk(KERN_ERR "Using a channel type which is configured out of "
  39                "UML\n");
  40         return -EIO;
  41 }
  42
  43 static int not_configged_write(int fd, const char *buf, int len, void *data)
  44 {
  45         printk(KERN_ERR "Using a channel type which is configured out of "
  46                "UML\n");
  47         return -EIO;
  48 }
  49
  50 static int not_configged_console_write(int fd, const char *buf, int len)
  51 {
  52         printk(KERN_ERR "Using a channel type which is configured out of "
  53                "UML\n");
  54         return -EIO;
  55 }
  56
  57 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
  58                                      unsigned short *cols)
  59 {
  60         printk(KERN_ERR "Using a channel type which is configured out of "
  61                "UML\n");
  62         return -ENODEV;
  63 }
  64
  65 static void not_configged_free(void *data)
  66 {
  67         printk(KERN_ERR "Using a channel type which is configured out of "
  68                "UML\n");
  69 }
  70
  71 static const struct chan_ops not_configged_ops = {
  72         .init           = not_configged_init,
  73         .open           = not_configged_open,
  74         .close          = not_configged_close,
  75         .read           = not_configged_read,
  76         .write          = not_configged_write,
  77         .console_write  = not_configged_console_write,
  78         .window_size    = not_configged_window_size,
  79         .free           = not_configged_free,
  80         .winch          = 0,
  81 };
  82 #endif /* CONFIG_NOCONFIG_CHAN */
  83
  84 static int open_one_chan(struct chan *chan)
  85 {
  86         int fd, err;
  87
  88         if (chan->opened)
  89                 return 0;
  90
  91         if (chan->ops->open == NULL)
  92                 fd = 0;
  93         else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
  94                                      chan->data, &chan->dev);
  95         if (fd < 0)
  96                 return fd;
  97
  98         err = os_set_fd_block(fd, 0);
  99         if (err) {
 100                 (*chan->ops->close)(fd, chan->data);
 101                 return err;
 102         }
 103
 104         chan->fd = fd;
 105
 106         chan->opened = 1;
 107         return 0;
 108 }
 109
 110 static int open_chan(struct list_head *chans)
 111 {
 112         struct list_head *ele;
 113         struct chan *chan;
 114         int ret, err = 0;
 115
 116         list_for_each(ele, chans) {
 117                 chan = list_entry(ele, struct chan, list);
 118                 ret = open_one_chan(chan);
 119                 if (chan->primary)
 120                         err = ret;
 121         }
 122         return err;
 123 }
 124
 125 void chan_enable_winch(struct chan *chan, struct tty_port *port)
 126 {
 127         if (chan && chan->primary && chan->ops->winch)
 128                 register_winch(chan->fd, port);
 129 }
 130
 131 static void line_timer_cb(struct work_struct *work)
 132 {
 133         struct line *line = container_of(work, struct line, task.work);
 134
 135         if (!line->throttled)
 136                 chan_interrupt(line, line->driver->read_irq);
 137 }
 138
 139 int enable_chan(struct line *line)
 140 {
 141         struct list_head *ele;
 142         struct chan *chan;
 143         int err;
 144
 145         INIT_DELAYED_WORK(&line->task, line_timer_cb);
 146
 147         list_for_each(ele, &line->chan_list) {
 148                 chan = list_entry(ele, struct chan, list);
 149                 err = open_one_chan(chan);
 150                 if (err) {
 151                         if (chan->primary)
 152                                 goto out_close;
 153
 154                         continue;
 155                 }
 156
 157                 if (chan->enabled)
 158                         continue;
 159                 err = line_setup_irq(chan->fd, chan->input, chan->output, line,
 160                                      chan);
 161                 if (err)
 162                         goto out_close;
 163
 164                 chan->enabled = 1;
 165         }
 166
 167         return 0;
 168
 169  out_close:
 170         close_chan(line);
 171         return err;
 172 }
 173
 174 static void close_one_chan(struct chan *chan, int delay_free_irq)
 175 {
 176         if (!chan->opened)
 177                 return;
 178
 179     /* we can safely call free now - it will be marked
 180      *  as free and freed once the IRQ stopped processing
 181      */
 182         if (chan->input && chan->enabled)
 183                 um_free_irq(chan->line->driver->read_irq, chan);
 184         if (chan->output && chan->enabled)
 185                 um_free_irq(chan->line->driver->write_irq, chan);
 186         chan->enabled = 0;
 187         if (chan->ops->close != NULL)
 188                 (*chan->ops->close)(chan->fd, chan->data);
 189
 190         chan->opened = 0;
 191         chan->fd = -1;
 192 }
 193
 194 void close_chan(struct line *line)
 195 {
 196         struct chan *chan;
 197
 198         /* Close in reverse order as open in case more than one of them
 199          * refers to the same device and they save and restore that device's
 200          * state.  Then, the first one opened will have the original state,
 201          * so it must be the last closed.
 202          */
 203         list_for_each_entry_reverse(chan, &line->chan_list, list) {
 204                 close_one_chan(chan, 0);
 205         }
 206 }
 207
 208 void deactivate_chan(struct chan *chan, int irq)
 209 {
 210         if (chan && chan->enabled)
 211                 deactivate_fd(chan->fd, irq);
 212 }
 213
 214 void reactivate_chan(struct chan *chan, int irq)
 215 {
 216         if (chan && chan->enabled)
 217                 reactivate_fd(chan->fd, irq);
 218 }
 219
 220 int write_chan(struct chan *chan, const char *buf, int len,
 221                int write_irq)
 222 {
 223         int n, ret = 0;
 224
 225         if (len == 0 || !chan || !chan->ops->write)
 226                 return 0;
 227
 228         n = chan->ops->write(chan->fd, buf, len, chan->data);
 229         if (chan->primary) {
 230                 ret = n;
 231                 if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
 232                         reactivate_fd(chan->fd, write_irq);
 233         }
 234         return ret;
 235 }
 236
 237 int console_write_chan(struct chan *chan, const char *buf, int len)
 238 {
 239         int n, ret = 0;
 240
 241         if (!chan || !chan->ops->console_write)
 242                 return 0;
 243
 244         n = chan->ops->console_write(chan->fd, buf, len);
 245         if (chan->primary)
 246                 ret = n;
 247         return ret;
 248 }
 249
 250 int console_open_chan(struct line *line, struct console *co)
 251 {
 252         int err;
 253
 254         err = open_chan(&line->chan_list);
 255         if (err)
 256                 return err;
 257
 258         printk(KERN_INFO "Console initialized on /dev/%s%d\n", co->name,
 259                co->index);
 260         return 0;
 261 }
 262
 263 int chan_window_size(struct line *line, unsigned short *rows_out,
 264                       unsigned short *cols_out)
 265 {
 266         struct chan *chan;
 267
 268         chan = line->chan_in;
 269         if (chan && chan->primary) {
 270                 if (chan->ops->window_size == NULL)
 271                         return 0;
 272                 return chan->ops->window_size(chan->fd, chan->data,
 273                                               rows_out, cols_out);
 274         }
 275         chan = line->chan_out;
 276         if (chan && chan->primary) {
 277                 if (chan->ops->window_size == NULL)
 278                         return 0;
 279                 return chan->ops->window_size(chan->fd, chan->data,
 280                                               rows_out, cols_out);
 281         }
 282         return 0;
 283 }
 284
 285 static void free_one_chan(struct chan *chan)
 286 {
 287         list_del(&chan->list);
 288
 289         close_one_chan(chan, 0);
 290
 291         if (chan->ops->free != NULL)
 292                 (*chan->ops->free)(chan->data);
 293
 294         if (chan->primary && chan->output)
 295                 ignore_sigio_fd(chan->fd);
 296         kfree(chan);
 297 }
 298
 299 static void free_chan(struct list_head *chans)
 300 {
 301         struct list_head *ele, *next;
 302         struct chan *chan;
 303
 304         list_for_each_safe(ele, next, chans) {
 305                 chan = list_entry(ele, struct chan, list);
 306                 free_one_chan(chan);
 307         }
 308 }
 309
 310 static int one_chan_config_string(struct chan *chan, char *str, int size,
 311                                   char **error_out)
 312 {
 313         int n = 0;
 314
 315         if (chan == NULL) {
 316                 CONFIG_CHUNK(str, size, n, "none", 1);
 317                 return n;
 318         }
 319
 320         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 321
 322         if (chan->dev == NULL) {
 323                 CONFIG_CHUNK(str, size, n, "", 1);
 324                 return n;
 325         }
 326
 327         CONFIG_CHUNK(str, size, n, ":", 0);
 328         CONFIG_CHUNK(str, size, n, chan->dev, 0);
 329
 330         return n;
 331 }
 332
 333 static int chan_pair_config_string(struct chan *in, struct chan *out,
 334                                    char *str, int size, char **error_out)
 335 {
 336         int n;
 337
 338         n = one_chan_config_string(in, str, size, error_out);
 339         str += n;
 340         size -= n;
 341
 342         if (in == out) {
 343                 CONFIG_CHUNK(str, size, n, "", 1);
 344                 return n;
 345         }
 346
 347         CONFIG_CHUNK(str, size, n, ",", 1);
 348         n = one_chan_config_string(out, str, size, error_out);
 349         str += n;
 350         size -= n;
 351         CONFIG_CHUNK(str, size, n, "", 1);
 352
 353         return n;
 354 }
 355
 356 int chan_config_string(struct line *line, char *str, int size,
 357                        char **error_out)
 358 {
 359         struct chan *in = line->chan_in, *out = line->chan_out;
 360
 361         if (in && !in->primary)
 362                 in = NULL;
 363         if (out && !out->primary)
 364                 out = NULL;
 365
 366         return chan_pair_config_string(in, out, str, size, error_out);
 367 }
 368
 369 struct chan_type {
 370         char *key;
 371         const struct chan_ops *ops;
 372 };
 373
 374 static const struct chan_type chan_table[] = {
 375         { "fd", &fd_ops },
 376
 377 #ifdef CONFIG_NULL_CHAN
 378         { "null", &null_ops },
 379 #else
 380         { "null", &not_configged_ops },
 381 #endif
 382
 383 #ifdef CONFIG_PORT_CHAN
 384         { "port", &port_ops },
 385 #else
 386         { "port", &not_configged_ops },
 387 #endif
 388
 389 #ifdef CONFIG_PTY_CHAN
 390         { "pty", &pty_ops },
 391         { "pts", &pts_ops },
 392 #else
 393         { "pty", &not_configged_ops },
 394         { "pts", &not_configged_ops },
 395 #endif
 396
 397 #ifdef CONFIG_TTY_CHAN
 398         { "tty", &tty_ops },
 399 #else
 400         { "tty", &not_configged_ops },
 401 #endif
 402
 403 #ifdef CONFIG_XTERM_CHAN
 404         { "xterm", &xterm_ops },
 405 #else
 406         { "xterm", &not_configged_ops },
 407 #endif
 408 };
 409
 410 static struct chan *parse_chan(struct line *line, char *str, int device,
 411                                const struct chan_opts *opts, char **error_out)
 412 {
 413         const struct chan_type *entry;
 414         const struct chan_ops *ops;
 415         struct chan *chan;
 416         void *data;
 417         int i;
 418
 419         ops = NULL;
 420         data = NULL;
 421         for(i = 0; i < ARRAY_SIZE(chan_table); i++) {
 422                 entry = &chan_table[i];
 423                 if (!strncmp(str, entry->key, strlen(entry->key))) {
 424                         ops = entry->ops;
 425                         str += strlen(entry->key);
 426                         break;
 427                 }
 428         }
 429         if (ops == NULL) {
 430                 *error_out = "No match for configured backends";
 431                 return NULL;
 432         }
 433
 434         data = (*ops->init)(str, device, opts);
 435         if (data == NULL) {
 436                 *error_out = "Configuration failed";
 437                 return NULL;
 438         }
 439
 440         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 441         if (chan == NULL) {
 442                 *error_out = "Memory allocation failed";
 443                 return NULL;
 444         }
 445         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
 446                                  .free_list     =
 447                                         LIST_HEAD_INIT(chan->free_list),
 448                                  .line          = line,
 449                                  .primary       = 1,
 450                                  .input         = 0,
 451                                  .output        = 0,
 452                                  .opened        = 0,
 453                                  .enabled       = 0,
 454                                  .fd            = -1,
 455                                  .ops           = ops,
 456                                  .data          = data });
 457         return chan;
 458 }
 459
 460 int parse_chan_pair(char *str, struct line *line, int device,
 461                     const struct chan_opts *opts, char **error_out)
 462 {
 463         struct list_head *chans = &line->chan_list;
 464         struct chan *new;
 465         char *in, *out;
 466
 467         if (!list_empty(chans)) {
 468                 line->chan_in = line->chan_out = NULL;
 469                 free_chan(chans);
 470                 INIT_LIST_HEAD(chans);
 471         }
 472
 473         if (!str)
 474                 return 0;
 475
 476         out = strchr(str, ',');
 477         if (out != NULL) {
 478                 in = str;
 479                 *out = '\0';
 480                 out++;
 481                 new = parse_chan(line, in, device, opts, error_out);
 482                 if (new == NULL)
 483                         return -1;
 484
 485                 new->input = 1;
 486                 list_add(&new->list, chans);
 487                 line->chan_in = new;
 488
 489                 new = parse_chan(line, out, device, opts, error_out);
 490                 if (new == NULL)
 491                         return -1;
 492
 493                 list_add(&new->list, chans);
 494                 new->output = 1;
 495                 line->chan_out = new;
 496         }
 497         else {
 498                 new = parse_chan(line, str, device, opts, error_out);
 499                 if (new == NULL)
 500                         return -1;
 501
 502                 list_add(&new->list, chans);
 503                 new->input = 1;
 504                 new->output = 1;
 505                 line->chan_in = line->chan_out = new;
 506         }
 507         return 0;
 508 }
 509
 510 void chan_interrupt(struct line *line, int irq)
 511 {
 512         struct tty_port *port = &line->port;
 513         struct chan *chan = line->chan_in;
 514         int err;
 515         char c;
 516
 517         if (!chan || !chan->ops->read)
 518                 goto out;
 519
 520         do {
 521                 if (!tty_buffer_request_room(port, 1)) {
 522                         schedule_delayed_work(&line->task, 1);
 523                         goto out;
 524                 }
 525                 err = chan->ops->read(chan->fd, &c, chan->data);
 526                 if (err > 0)
 527                         tty_insert_flip_char(port, c, TTY_NORMAL);
 528         } while (err > 0);
 529
 530         if (err == 0)
 531                 reactivate_fd(chan->fd, irq);
 532         if (err == -EIO) {
 533                 if (chan->primary) {
 534                         tty_port_tty_hangup(&line->port, false);
 535                         if (line->chan_out != chan)
 536                                 close_one_chan(line->chan_out, 1);
 537                 }
 538                 close_one_chan(chan, 1);
 539                 if (chan->primary)
 540                         return;
 541         }
 542  out:
 543         tty_flip_buffer_push(port);
 544 }