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[nao-ulib.git] / kernel / 2.6.29.6-aldebaran-rt / arch / um / drivers / line.c
blob14a102e877d66e51a1e28a4f5a64ce23b509050a
1 /*
2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
6 #include "linux/irqreturn.h"
7 #include "linux/kd.h"
8 #include "chan_kern.h"
9 #include "irq_kern.h"
10 #include "irq_user.h"
11 #include "kern_util.h"
12 #include "os.h"
14 #define LINE_BUFSIZE 4096
16 static irqreturn_t line_interrupt(int irq, void *data)
18 struct chan *chan = data;
19 struct line *line = chan->line;
20 struct tty_struct *tty = line->tty;
22 if (line)
23 chan_interrupt(&line->chan_list, &line->task, tty, irq);
24 return IRQ_HANDLED;
27 static void line_timer_cb(struct work_struct *work)
29 struct line *line = container_of(work, struct line, task.work);
31 if (!line->throttled)
32 chan_interrupt(&line->chan_list, &line->task, line->tty,
33 line->driver->read_irq);
37 * Returns the free space inside the ring buffer of this line.
39 * Should be called while holding line->lock (this does not modify data).
41 static int write_room(struct line *line)
43 int n;
45 if (line->buffer == NULL)
46 return LINE_BUFSIZE - 1;
48 /* This is for the case where the buffer is wrapped! */
49 n = line->head - line->tail;
51 if (n <= 0)
52 n += LINE_BUFSIZE; /* The other case */
53 return n - 1;
56 int line_write_room(struct tty_struct *tty)
58 struct line *line = tty->driver_data;
59 unsigned long flags;
60 int room;
62 spin_lock_irqsave(&line->lock, flags);
63 room = write_room(line);
64 spin_unlock_irqrestore(&line->lock, flags);
66 return room;
69 int line_chars_in_buffer(struct tty_struct *tty)
71 struct line *line = tty->driver_data;
72 unsigned long flags;
73 int ret;
75 spin_lock_irqsave(&line->lock, flags);
76 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
77 ret = LINE_BUFSIZE - (write_room(line) + 1);
78 spin_unlock_irqrestore(&line->lock, flags);
80 return ret;
84 * This copies the content of buf into the circular buffer associated with
85 * this line.
86 * The return value is the number of characters actually copied, i.e. the ones
87 * for which there was space: this function is not supposed to ever flush out
88 * the circular buffer.
90 * Must be called while holding line->lock!
92 static int buffer_data(struct line *line, const char *buf, int len)
94 int end, room;
96 if (line->buffer == NULL) {
97 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
98 if (line->buffer == NULL) {
99 printk(KERN_ERR "buffer_data - atomic allocation "
100 "failed\n");
101 return 0;
103 line->head = line->buffer;
104 line->tail = line->buffer;
107 room = write_room(line);
108 len = (len > room) ? room : len;
110 end = line->buffer + LINE_BUFSIZE - line->tail;
112 if (len < end) {
113 memcpy(line->tail, buf, len);
114 line->tail += len;
116 else {
117 /* The circular buffer is wrapping */
118 memcpy(line->tail, buf, end);
119 buf += end;
120 memcpy(line->buffer, buf, len - end);
121 line->tail = line->buffer + len - end;
124 return len;
128 * Flushes the ring buffer to the output channels. That is, write_chan is
129 * called, passing it line->head as buffer, and an appropriate count.
131 * On exit, returns 1 when the buffer is empty,
132 * 0 when the buffer is not empty on exit,
133 * and -errno when an error occurred.
135 * Must be called while holding line->lock!*/
136 static int flush_buffer(struct line *line)
138 int n, count;
140 if ((line->buffer == NULL) || (line->head == line->tail))
141 return 1;
143 if (line->tail < line->head) {
144 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
145 count = line->buffer + LINE_BUFSIZE - line->head;
147 n = write_chan(&line->chan_list, line->head, count,
148 line->driver->write_irq);
149 if (n < 0)
150 return n;
151 if (n == count) {
153 * We have flushed from ->head to buffer end, now we
154 * must flush only from the beginning to ->tail.
156 line->head = line->buffer;
157 } else {
158 line->head += n;
159 return 0;
163 count = line->tail - line->head;
164 n = write_chan(&line->chan_list, line->head, count,
165 line->driver->write_irq);
167 if (n < 0)
168 return n;
170 line->head += n;
171 return line->head == line->tail;
174 void line_flush_buffer(struct tty_struct *tty)
176 struct line *line = tty->driver_data;
177 unsigned long flags;
178 int err;
180 spin_lock_irqsave(&line->lock, flags);
181 err = flush_buffer(line);
182 spin_unlock_irqrestore(&line->lock, flags);
186 * We map both ->flush_chars and ->put_char (which go in pair) onto
187 * ->flush_buffer and ->write. Hope it's not that bad.
189 void line_flush_chars(struct tty_struct *tty)
191 line_flush_buffer(tty);
194 int line_put_char(struct tty_struct *tty, unsigned char ch)
196 return line_write(tty, &ch, sizeof(ch));
199 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
201 struct line *line = tty->driver_data;
202 unsigned long flags;
203 int n, ret = 0;
205 spin_lock_irqsave(&line->lock, flags);
206 if (line->head != line->tail)
207 ret = buffer_data(line, buf, len);
208 else {
209 n = write_chan(&line->chan_list, buf, len,
210 line->driver->write_irq);
211 if (n < 0) {
212 ret = n;
213 goto out_up;
216 len -= n;
217 ret += n;
218 if (len > 0)
219 ret += buffer_data(line, buf + n, len);
221 out_up:
222 spin_unlock_irqrestore(&line->lock, flags);
223 return ret;
226 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
228 /* nothing */
231 static const struct {
232 int cmd;
233 char *level;
234 char *name;
235 } tty_ioctls[] = {
236 /* don't print these, they flood the log ... */
237 { TCGETS, NULL, "TCGETS" },
238 { TCSETS, NULL, "TCSETS" },
239 { TCSETSW, NULL, "TCSETSW" },
240 { TCFLSH, NULL, "TCFLSH" },
241 { TCSBRK, NULL, "TCSBRK" },
243 /* general tty stuff */
244 { TCSETSF, KERN_DEBUG, "TCSETSF" },
245 { TCGETA, KERN_DEBUG, "TCGETA" },
246 { TIOCMGET, KERN_DEBUG, "TIOCMGET" },
247 { TCSBRKP, KERN_DEBUG, "TCSBRKP" },
248 { TIOCMSET, KERN_DEBUG, "TIOCMSET" },
250 /* linux-specific ones */
251 { TIOCLINUX, KERN_INFO, "TIOCLINUX" },
252 { KDGKBMODE, KERN_INFO, "KDGKBMODE" },
253 { KDGKBTYPE, KERN_INFO, "KDGKBTYPE" },
254 { KDSIGACCEPT, KERN_INFO, "KDSIGACCEPT" },
257 int line_ioctl(struct tty_struct *tty, struct file * file,
258 unsigned int cmd, unsigned long arg)
260 int ret;
261 int i;
263 ret = 0;
264 switch(cmd) {
265 #ifdef TIOCGETP
266 case TIOCGETP:
267 case TIOCSETP:
268 case TIOCSETN:
269 #endif
270 #ifdef TIOCGETC
271 case TIOCGETC:
272 case TIOCSETC:
273 #endif
274 #ifdef TIOCGLTC
275 case TIOCGLTC:
276 case TIOCSLTC:
277 #endif
278 /* Note: these are out of date as we now have TCGETS2 etc but this
279 whole lot should probably go away */
280 case TCGETS:
281 case TCSETSF:
282 case TCSETSW:
283 case TCSETS:
284 case TCGETA:
285 case TCSETAF:
286 case TCSETAW:
287 case TCSETA:
288 case TCXONC:
289 case TCFLSH:
290 case TIOCOUTQ:
291 case TIOCINQ:
292 case TIOCGLCKTRMIOS:
293 case TIOCSLCKTRMIOS:
294 case TIOCPKT:
295 case TIOCGSOFTCAR:
296 case TIOCSSOFTCAR:
297 return -ENOIOCTLCMD;
298 #if 0
299 case TCwhatever:
300 /* do something */
301 break;
302 #endif
303 default:
304 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
305 if (cmd == tty_ioctls[i].cmd)
306 break;
307 if (i == ARRAY_SIZE(tty_ioctls)) {
308 printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
309 __func__, tty->name, cmd);
311 ret = -ENOIOCTLCMD;
312 break;
314 return ret;
317 void line_throttle(struct tty_struct *tty)
319 struct line *line = tty->driver_data;
321 deactivate_chan(&line->chan_list, line->driver->read_irq);
322 line->throttled = 1;
325 void line_unthrottle(struct tty_struct *tty)
327 struct line *line = tty->driver_data;
329 line->throttled = 0;
330 chan_interrupt(&line->chan_list, &line->task, tty,
331 line->driver->read_irq);
334 * Maybe there is enough stuff pending that calling the interrupt
335 * throttles us again. In this case, line->throttled will be 1
336 * again and we shouldn't turn the interrupt back on.
338 if (!line->throttled)
339 reactivate_chan(&line->chan_list, line->driver->read_irq);
342 static irqreturn_t line_write_interrupt(int irq, void *data)
344 struct chan *chan = data;
345 struct line *line = chan->line;
346 struct tty_struct *tty = line->tty;
347 int err;
350 * Interrupts are disabled here because we registered the interrupt with
351 * IRQF_DISABLED (see line_setup_irq).
354 spin_lock(&line->lock);
355 err = flush_buffer(line);
356 if (err == 0) {
357 return IRQ_NONE;
358 } else if (err < 0) {
359 line->head = line->buffer;
360 line->tail = line->buffer;
362 spin_unlock(&line->lock);
364 if (tty == NULL)
365 return IRQ_NONE;
367 tty_wakeup(tty);
368 return IRQ_HANDLED;
371 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
373 const struct line_driver *driver = line->driver;
374 int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
376 if (input)
377 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
378 line_interrupt, flags,
379 driver->read_irq_name, data);
380 if (err)
381 return err;
382 if (output)
383 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
384 line_write_interrupt, flags,
385 driver->write_irq_name, data);
386 line->have_irq = 1;
387 return err;
391 * Normally, a driver like this can rely mostly on the tty layer
392 * locking, particularly when it comes to the driver structure.
393 * However, in this case, mconsole requests can come in "from the
394 * side", and race with opens and closes.
396 * mconsole config requests will want to be sure the device isn't in
397 * use, and get_config, open, and close will want a stable
398 * configuration. The checking and modification of the configuration
399 * is done under a spinlock. Checking whether the device is in use is
400 * line->tty->count > 1, also under the spinlock.
402 * tty->count serves to decide whether the device should be enabled or
403 * disabled on the host. If it's equal to 1, then we are doing the
404 * first open or last close. Otherwise, open and close just return.
407 int line_open(struct line *lines, struct tty_struct *tty)
409 struct line *line = &lines[tty->index];
410 int err = -ENODEV;
412 spin_lock(&line->count_lock);
413 if (!line->valid)
414 goto out_unlock;
416 err = 0;
417 if (tty->count > 1)
418 goto out_unlock;
420 spin_unlock(&line->count_lock);
422 tty->driver_data = line;
423 line->tty = tty;
425 err = enable_chan(line);
426 if (err)
427 return err;
429 INIT_DELAYED_WORK(&line->task, line_timer_cb);
431 if (!line->sigio) {
432 chan_enable_winch(&line->chan_list, tty);
433 line->sigio = 1;
436 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
437 &tty->winsize.ws_col);
439 return err;
441 out_unlock:
442 spin_unlock(&line->count_lock);
443 return err;
446 static void unregister_winch(struct tty_struct *tty);
448 void line_close(struct tty_struct *tty, struct file * filp)
450 struct line *line = tty->driver_data;
453 * If line_open fails (and tty->driver_data is never set),
454 * tty_open will call line_close. So just return in this case.
456 if (line == NULL)
457 return;
459 /* We ignore the error anyway! */
460 flush_buffer(line);
462 spin_lock(&line->count_lock);
463 if (!line->valid)
464 goto out_unlock;
466 if (tty->count > 1)
467 goto out_unlock;
469 spin_unlock(&line->count_lock);
471 line->tty = NULL;
472 tty->driver_data = NULL;
474 if (line->sigio) {
475 unregister_winch(tty);
476 line->sigio = 0;
479 return;
481 out_unlock:
482 spin_unlock(&line->count_lock);
485 void close_lines(struct line *lines, int nlines)
487 int i;
489 for(i = 0; i < nlines; i++)
490 close_chan(&lines[i].chan_list, 0);
493 static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
494 char **error_out)
496 struct line *line = &lines[n];
497 int err = -EINVAL;
499 spin_lock(&line->count_lock);
501 if (line->tty != NULL) {
502 *error_out = "Device is already open";
503 goto out;
506 if (line->init_pri <= init_prio) {
507 line->init_pri = init_prio;
508 if (!strcmp(init, "none"))
509 line->valid = 0;
510 else {
511 line->init_str = init;
512 line->valid = 1;
515 err = 0;
516 out:
517 spin_unlock(&line->count_lock);
518 return err;
522 * Common setup code for both startup command line and mconsole initialization.
523 * @lines contains the array (of size @num) to modify;
524 * @init is the setup string;
525 * @error_out is an error string in the case of failure;
528 int line_setup(struct line *lines, unsigned int num, char *init,
529 char **error_out)
531 int i, n, err;
532 char *end;
534 if (*init == '=') {
536 * We said con=/ssl= instead of con#=, so we are configuring all
537 * consoles at once.
539 n = -1;
541 else {
542 n = simple_strtoul(init, &end, 0);
543 if (*end != '=') {
544 *error_out = "Couldn't parse device number";
545 return -EINVAL;
547 init = end;
549 init++;
551 if (n >= (signed int) num) {
552 *error_out = "Device number out of range";
553 return -EINVAL;
555 else if (n >= 0) {
556 err = setup_one_line(lines, n, init, INIT_ONE, error_out);
557 if (err)
558 return err;
560 else {
561 for(i = 0; i < num; i++) {
562 err = setup_one_line(lines, i, init, INIT_ALL,
563 error_out);
564 if (err)
565 return err;
568 return n == -1 ? num : n;
571 int line_config(struct line *lines, unsigned int num, char *str,
572 const struct chan_opts *opts, char **error_out)
574 struct line *line;
575 char *new;
576 int n;
578 if (*str == '=') {
579 *error_out = "Can't configure all devices from mconsole";
580 return -EINVAL;
583 new = kstrdup(str, GFP_KERNEL);
584 if (new == NULL) {
585 *error_out = "Failed to allocate memory";
586 return -ENOMEM;
588 n = line_setup(lines, num, new, error_out);
589 if (n < 0)
590 return n;
592 line = &lines[n];
593 return parse_chan_pair(line->init_str, line, n, opts, error_out);
596 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
597 int size, char **error_out)
599 struct line *line;
600 char *end;
601 int dev, n = 0;
603 dev = simple_strtoul(name, &end, 0);
604 if ((*end != '\0') || (end == name)) {
605 *error_out = "line_get_config failed to parse device number";
606 return 0;
609 if ((dev < 0) || (dev >= num)) {
610 *error_out = "device number out of range";
611 return 0;
614 line = &lines[dev];
616 spin_lock(&line->count_lock);
617 if (!line->valid)
618 CONFIG_CHUNK(str, size, n, "none", 1);
619 else if (line->tty == NULL)
620 CONFIG_CHUNK(str, size, n, line->init_str, 1);
621 else n = chan_config_string(&line->chan_list, str, size, error_out);
622 spin_unlock(&line->count_lock);
624 return n;
627 int line_id(char **str, int *start_out, int *end_out)
629 char *end;
630 int n;
632 n = simple_strtoul(*str, &end, 0);
633 if ((*end != '\0') || (end == *str))
634 return -1;
636 *str = end;
637 *start_out = n;
638 *end_out = n;
639 return n;
642 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
644 int err;
645 char config[sizeof("conxxxx=none\0")];
647 sprintf(config, "%d=none", n);
648 err = line_setup(lines, num, config, error_out);
649 if (err >= 0)
650 err = 0;
651 return err;
654 struct tty_driver *register_lines(struct line_driver *line_driver,
655 const struct tty_operations *ops,
656 struct line *lines, int nlines)
658 int i;
659 struct tty_driver *driver = alloc_tty_driver(nlines);
661 if (!driver)
662 return NULL;
664 driver->driver_name = line_driver->name;
665 driver->name = line_driver->device_name;
666 driver->major = line_driver->major;
667 driver->minor_start = line_driver->minor_start;
668 driver->type = line_driver->type;
669 driver->subtype = line_driver->subtype;
670 driver->flags = TTY_DRIVER_REAL_RAW;
671 driver->init_termios = tty_std_termios;
672 tty_set_operations(driver, ops);
674 if (tty_register_driver(driver)) {
675 printk(KERN_ERR "register_lines : can't register %s driver\n",
676 line_driver->name);
677 put_tty_driver(driver);
678 return NULL;
681 for(i = 0; i < nlines; i++) {
682 if (!lines[i].valid)
683 tty_unregister_device(driver, i);
686 mconsole_register_dev(&line_driver->mc);
687 return driver;
690 static DEFINE_SPINLOCK(winch_handler_lock);
691 static LIST_HEAD(winch_handlers);
693 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
695 struct line *line;
696 char *error;
697 int i;
699 for(i = 0; i < nlines; i++) {
700 line = &lines[i];
701 INIT_LIST_HEAD(&line->chan_list);
703 if (line->init_str == NULL)
704 continue;
706 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
707 if (line->init_str == NULL)
708 printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
710 if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
711 printk(KERN_ERR "parse_chan_pair failed for "
712 "device %d : %s\n", i, error);
713 line->valid = 0;
718 struct winch {
719 struct list_head list;
720 int fd;
721 int tty_fd;
722 int pid;
723 struct tty_struct *tty;
724 unsigned long stack;
727 static void free_winch(struct winch *winch, int free_irq_ok)
729 list_del(&winch->list);
731 if (winch->pid != -1)
732 os_kill_process(winch->pid, 1);
733 if (winch->fd != -1)
734 os_close_file(winch->fd);
735 if (winch->stack != 0)
736 free_stack(winch->stack, 0);
737 if (free_irq_ok)
738 free_irq(WINCH_IRQ, winch);
739 kfree(winch);
742 static irqreturn_t winch_interrupt(int irq, void *data)
744 struct winch *winch = data;
745 struct tty_struct *tty;
746 struct line *line;
747 int err;
748 char c;
750 if (winch->fd != -1) {
751 err = generic_read(winch->fd, &c, NULL);
752 if (err < 0) {
753 if (err != -EAGAIN) {
754 printk(KERN_ERR "winch_interrupt : "
755 "read failed, errno = %d\n", -err);
756 printk(KERN_ERR "fd %d is losing SIGWINCH "
757 "support\n", winch->tty_fd);
758 free_winch(winch, 0);
759 return IRQ_HANDLED;
761 goto out;
764 tty = winch->tty;
765 if (tty != NULL) {
766 line = tty->driver_data;
767 if (line != NULL) {
768 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
769 &tty->winsize.ws_col);
770 kill_pgrp(tty->pgrp, SIGWINCH, 1);
773 out:
774 if (winch->fd != -1)
775 reactivate_fd(winch->fd, WINCH_IRQ);
776 return IRQ_HANDLED;
779 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
780 unsigned long stack)
782 struct winch *winch;
784 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
785 if (winch == NULL) {
786 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
787 goto cleanup;
790 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
791 .fd = fd,
792 .tty_fd = tty_fd,
793 .pid = pid,
794 .tty = tty,
795 .stack = stack });
797 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
798 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
799 "winch", winch) < 0) {
800 printk(KERN_ERR "register_winch_irq - failed to register "
801 "IRQ\n");
802 goto out_free;
805 spin_lock(&winch_handler_lock);
806 list_add(&winch->list, &winch_handlers);
807 spin_unlock(&winch_handler_lock);
809 return;
811 out_free:
812 kfree(winch);
813 cleanup:
814 os_kill_process(pid, 1);
815 os_close_file(fd);
816 if (stack != 0)
817 free_stack(stack, 0);
820 static void unregister_winch(struct tty_struct *tty)
822 struct list_head *ele;
823 struct winch *winch;
825 spin_lock(&winch_handler_lock);
827 list_for_each(ele, &winch_handlers) {
828 winch = list_entry(ele, struct winch, list);
829 if (winch->tty == tty) {
830 free_winch(winch, 1);
831 break;
834 spin_unlock(&winch_handler_lock);
837 static void winch_cleanup(void)
839 struct list_head *ele, *next;
840 struct winch *winch;
842 spin_lock(&winch_handler_lock);
844 list_for_each_safe(ele, next, &winch_handlers) {
845 winch = list_entry(ele, struct winch, list);
846 free_winch(winch, 1);
849 spin_unlock(&winch_handler_lock);
851 __uml_exitcall(winch_cleanup);
853 char *add_xterm_umid(char *base)
855 char *umid, *title;
856 int len;
858 umid = get_umid();
859 if (*umid == '\0')
860 return base;
862 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
863 title = kmalloc(len, GFP_KERNEL);
864 if (title == NULL) {
865 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
866 return base;
869 snprintf(title, len, "%s (%s)", base, umid);
870 return title;