ia64/kvm: compilation fix. export account_system_vtime.
[pv_ops_mirror.git] / arch / um / drivers / line.c
blob5047490fc299aa69ae999b348760277767684569
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 case TCGETS:
279 case TCSETSF:
280 case TCSETSW:
281 case TCSETS:
282 case TCGETA:
283 case TCSETAF:
284 case TCSETAW:
285 case TCSETA:
286 case TCXONC:
287 case TCFLSH:
288 case TIOCOUTQ:
289 case TIOCINQ:
290 case TIOCGLCKTRMIOS:
291 case TIOCSLCKTRMIOS:
292 case TIOCPKT:
293 case TIOCGSOFTCAR:
294 case TIOCSSOFTCAR:
295 return -ENOIOCTLCMD;
296 #if 0
297 case TCwhatever:
298 /* do something */
299 break;
300 #endif
301 default:
302 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
303 if (cmd == tty_ioctls[i].cmd)
304 break;
305 if (i == ARRAY_SIZE(tty_ioctls)) {
306 printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
307 __func__, tty->name, cmd);
309 ret = -ENOIOCTLCMD;
310 break;
312 return ret;
315 void line_throttle(struct tty_struct *tty)
317 struct line *line = tty->driver_data;
319 deactivate_chan(&line->chan_list, line->driver->read_irq);
320 line->throttled = 1;
323 void line_unthrottle(struct tty_struct *tty)
325 struct line *line = tty->driver_data;
327 line->throttled = 0;
328 chan_interrupt(&line->chan_list, &line->task, tty,
329 line->driver->read_irq);
332 * Maybe there is enough stuff pending that calling the interrupt
333 * throttles us again. In this case, line->throttled will be 1
334 * again and we shouldn't turn the interrupt back on.
336 if (!line->throttled)
337 reactivate_chan(&line->chan_list, line->driver->read_irq);
340 static irqreturn_t line_write_interrupt(int irq, void *data)
342 struct chan *chan = data;
343 struct line *line = chan->line;
344 struct tty_struct *tty = line->tty;
345 int err;
348 * Interrupts are disabled here because we registered the interrupt with
349 * IRQF_DISABLED (see line_setup_irq).
352 spin_lock(&line->lock);
353 err = flush_buffer(line);
354 if (err == 0) {
355 return IRQ_NONE;
356 } else if (err < 0) {
357 line->head = line->buffer;
358 line->tail = line->buffer;
360 spin_unlock(&line->lock);
362 if (tty == NULL)
363 return IRQ_NONE;
365 if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
366 (tty->ldisc.write_wakeup != NULL))
367 (tty->ldisc.write_wakeup)(tty);
370 * BLOCKING mode
371 * In blocking mode, everything sleeps on tty->write_wait.
372 * Sleeping in the console driver would break non-blocking
373 * writes.
376 if (waitqueue_active(&tty->write_wait))
377 wake_up_interruptible(&tty->write_wait);
378 return IRQ_HANDLED;
381 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
383 const struct line_driver *driver = line->driver;
384 int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
386 if (input)
387 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
388 line_interrupt, flags,
389 driver->read_irq_name, data);
390 if (err)
391 return err;
392 if (output)
393 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
394 line_write_interrupt, flags,
395 driver->write_irq_name, data);
396 line->have_irq = 1;
397 return err;
401 * Normally, a driver like this can rely mostly on the tty layer
402 * locking, particularly when it comes to the driver structure.
403 * However, in this case, mconsole requests can come in "from the
404 * side", and race with opens and closes.
406 * mconsole config requests will want to be sure the device isn't in
407 * use, and get_config, open, and close will want a stable
408 * configuration. The checking and modification of the configuration
409 * is done under a spinlock. Checking whether the device is in use is
410 * line->tty->count > 1, also under the spinlock.
412 * tty->count serves to decide whether the device should be enabled or
413 * disabled on the host. If it's equal to 1, then we are doing the
414 * first open or last close. Otherwise, open and close just return.
417 int line_open(struct line *lines, struct tty_struct *tty)
419 struct line *line = &lines[tty->index];
420 int err = -ENODEV;
422 spin_lock(&line->count_lock);
423 if (!line->valid)
424 goto out_unlock;
426 err = 0;
427 if (tty->count > 1)
428 goto out_unlock;
430 spin_unlock(&line->count_lock);
432 tty->driver_data = line;
433 line->tty = tty;
435 err = enable_chan(line);
436 if (err)
437 return err;
439 INIT_DELAYED_WORK(&line->task, line_timer_cb);
441 if (!line->sigio) {
442 chan_enable_winch(&line->chan_list, tty);
443 line->sigio = 1;
446 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
447 &tty->winsize.ws_col);
449 return err;
451 out_unlock:
452 spin_unlock(&line->count_lock);
453 return err;
456 static void unregister_winch(struct tty_struct *tty);
458 void line_close(struct tty_struct *tty, struct file * filp)
460 struct line *line = tty->driver_data;
463 * If line_open fails (and tty->driver_data is never set),
464 * tty_open will call line_close. So just return in this case.
466 if (line == NULL)
467 return;
469 /* We ignore the error anyway! */
470 flush_buffer(line);
472 spin_lock(&line->count_lock);
473 if (!line->valid)
474 goto out_unlock;
476 if (tty->count > 1)
477 goto out_unlock;
479 spin_unlock(&line->count_lock);
481 line->tty = NULL;
482 tty->driver_data = NULL;
484 if (line->sigio) {
485 unregister_winch(tty);
486 line->sigio = 0;
489 return;
491 out_unlock:
492 spin_unlock(&line->count_lock);
495 void close_lines(struct line *lines, int nlines)
497 int i;
499 for(i = 0; i < nlines; i++)
500 close_chan(&lines[i].chan_list, 0);
503 static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
504 char **error_out)
506 struct line *line = &lines[n];
507 int err = -EINVAL;
509 spin_lock(&line->count_lock);
511 if (line->tty != NULL) {
512 *error_out = "Device is already open";
513 goto out;
516 if (line->init_pri <= init_prio) {
517 line->init_pri = init_prio;
518 if (!strcmp(init, "none"))
519 line->valid = 0;
520 else {
521 line->init_str = init;
522 line->valid = 1;
525 err = 0;
526 out:
527 spin_unlock(&line->count_lock);
528 return err;
532 * Common setup code for both startup command line and mconsole initialization.
533 * @lines contains the array (of size @num) to modify;
534 * @init is the setup string;
535 * @error_out is an error string in the case of failure;
538 int line_setup(struct line *lines, unsigned int num, char *init,
539 char **error_out)
541 int i, n, err;
542 char *end;
544 if (*init == '=') {
546 * We said con=/ssl= instead of con#=, so we are configuring all
547 * consoles at once.
549 n = -1;
551 else {
552 n = simple_strtoul(init, &end, 0);
553 if (*end != '=') {
554 *error_out = "Couldn't parse device number";
555 return -EINVAL;
557 init = end;
559 init++;
561 if (n >= (signed int) num) {
562 *error_out = "Device number out of range";
563 return -EINVAL;
565 else if (n >= 0) {
566 err = setup_one_line(lines, n, init, INIT_ONE, error_out);
567 if (err)
568 return err;
570 else {
571 for(i = 0; i < num; i++) {
572 err = setup_one_line(lines, i, init, INIT_ALL,
573 error_out);
574 if (err)
575 return err;
578 return n == -1 ? num : n;
581 int line_config(struct line *lines, unsigned int num, char *str,
582 const struct chan_opts *opts, char **error_out)
584 struct line *line;
585 char *new;
586 int n;
588 if (*str == '=') {
589 *error_out = "Can't configure all devices from mconsole";
590 return -EINVAL;
593 new = kstrdup(str, GFP_KERNEL);
594 if (new == NULL) {
595 *error_out = "Failed to allocate memory";
596 return -ENOMEM;
598 n = line_setup(lines, num, new, error_out);
599 if (n < 0)
600 return n;
602 line = &lines[n];
603 return parse_chan_pair(line->init_str, line, n, opts, error_out);
606 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
607 int size, char **error_out)
609 struct line *line;
610 char *end;
611 int dev, n = 0;
613 dev = simple_strtoul(name, &end, 0);
614 if ((*end != '\0') || (end == name)) {
615 *error_out = "line_get_config failed to parse device number";
616 return 0;
619 if ((dev < 0) || (dev >= num)) {
620 *error_out = "device number out of range";
621 return 0;
624 line = &lines[dev];
626 spin_lock(&line->count_lock);
627 if (!line->valid)
628 CONFIG_CHUNK(str, size, n, "none", 1);
629 else if (line->tty == NULL)
630 CONFIG_CHUNK(str, size, n, line->init_str, 1);
631 else n = chan_config_string(&line->chan_list, str, size, error_out);
632 spin_unlock(&line->count_lock);
634 return n;
637 int line_id(char **str, int *start_out, int *end_out)
639 char *end;
640 int n;
642 n = simple_strtoul(*str, &end, 0);
643 if ((*end != '\0') || (end == *str))
644 return -1;
646 *str = end;
647 *start_out = n;
648 *end_out = n;
649 return n;
652 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
654 int err;
655 char config[sizeof("conxxxx=none\0")];
657 sprintf(config, "%d=none", n);
658 err = line_setup(lines, num, config, error_out);
659 if (err >= 0)
660 err = 0;
661 return err;
664 struct tty_driver *register_lines(struct line_driver *line_driver,
665 const struct tty_operations *ops,
666 struct line *lines, int nlines)
668 int i;
669 struct tty_driver *driver = alloc_tty_driver(nlines);
671 if (!driver)
672 return NULL;
674 driver->driver_name = line_driver->name;
675 driver->name = line_driver->device_name;
676 driver->major = line_driver->major;
677 driver->minor_start = line_driver->minor_start;
678 driver->type = line_driver->type;
679 driver->subtype = line_driver->subtype;
680 driver->flags = TTY_DRIVER_REAL_RAW;
681 driver->init_termios = tty_std_termios;
682 tty_set_operations(driver, ops);
684 if (tty_register_driver(driver)) {
685 printk(KERN_ERR "register_lines : can't register %s driver\n",
686 line_driver->name);
687 put_tty_driver(driver);
688 return NULL;
691 for(i = 0; i < nlines; i++) {
692 if (!lines[i].valid)
693 tty_unregister_device(driver, i);
696 mconsole_register_dev(&line_driver->mc);
697 return driver;
700 static DEFINE_SPINLOCK(winch_handler_lock);
701 static LIST_HEAD(winch_handlers);
703 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
705 struct line *line;
706 char *error;
707 int i;
709 for(i = 0; i < nlines; i++) {
710 line = &lines[i];
711 INIT_LIST_HEAD(&line->chan_list);
713 if (line->init_str == NULL)
714 continue;
716 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
717 if (line->init_str == NULL)
718 printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
720 if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
721 printk(KERN_ERR "parse_chan_pair failed for "
722 "device %d : %s\n", i, error);
723 line->valid = 0;
728 struct winch {
729 struct list_head list;
730 int fd;
731 int tty_fd;
732 int pid;
733 struct tty_struct *tty;
734 unsigned long stack;
737 static void free_winch(struct winch *winch, int free_irq_ok)
739 list_del(&winch->list);
741 if (winch->pid != -1)
742 os_kill_process(winch->pid, 1);
743 if (winch->fd != -1)
744 os_close_file(winch->fd);
745 if (winch->stack != 0)
746 free_stack(winch->stack, 0);
747 if (free_irq_ok)
748 free_irq(WINCH_IRQ, winch);
749 kfree(winch);
752 static irqreturn_t winch_interrupt(int irq, void *data)
754 struct winch *winch = data;
755 struct tty_struct *tty;
756 struct line *line;
757 int err;
758 char c;
760 if (winch->fd != -1) {
761 err = generic_read(winch->fd, &c, NULL);
762 if (err < 0) {
763 if (err != -EAGAIN) {
764 printk(KERN_ERR "winch_interrupt : "
765 "read failed, errno = %d\n", -err);
766 printk(KERN_ERR "fd %d is losing SIGWINCH "
767 "support\n", winch->tty_fd);
768 free_winch(winch, 0);
769 return IRQ_HANDLED;
771 goto out;
774 tty = winch->tty;
775 if (tty != NULL) {
776 line = tty->driver_data;
777 if (line != NULL) {
778 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
779 &tty->winsize.ws_col);
780 kill_pgrp(tty->pgrp, SIGWINCH, 1);
783 out:
784 if (winch->fd != -1)
785 reactivate_fd(winch->fd, WINCH_IRQ);
786 return IRQ_HANDLED;
789 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
790 unsigned long stack)
792 struct winch *winch;
794 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
795 if (winch == NULL) {
796 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
797 goto cleanup;
800 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
801 .fd = fd,
802 .tty_fd = tty_fd,
803 .pid = pid,
804 .tty = tty,
805 .stack = stack });
807 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
808 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
809 "winch", winch) < 0) {
810 printk(KERN_ERR "register_winch_irq - failed to register "
811 "IRQ\n");
812 goto out_free;
815 spin_lock(&winch_handler_lock);
816 list_add(&winch->list, &winch_handlers);
817 spin_unlock(&winch_handler_lock);
819 return;
821 out_free:
822 kfree(winch);
823 cleanup:
824 os_kill_process(pid, 1);
825 os_close_file(fd);
826 if (stack != 0)
827 free_stack(stack, 0);
830 static void unregister_winch(struct tty_struct *tty)
832 struct list_head *ele;
833 struct winch *winch;
835 spin_lock(&winch_handler_lock);
837 list_for_each(ele, &winch_handlers) {
838 winch = list_entry(ele, struct winch, list);
839 if (winch->tty == tty) {
840 free_winch(winch, 1);
841 break;
844 spin_unlock(&winch_handler_lock);
847 static void winch_cleanup(void)
849 struct list_head *ele, *next;
850 struct winch *winch;
852 spin_lock(&winch_handler_lock);
854 list_for_each_safe(ele, next, &winch_handlers) {
855 winch = list_entry(ele, struct winch, list);
856 free_winch(winch, 1);
859 spin_unlock(&winch_handler_lock);
861 __uml_exitcall(winch_cleanup);
863 char *add_xterm_umid(char *base)
865 char *umid, *title;
866 int len;
868 umid = get_umid();
869 if (*umid == '\0')
870 return base;
872 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
873 title = kmalloc(len, GFP_KERNEL);
874 if (title == NULL) {
875 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
876 return base;
879 snprintf(title, len, "%s (%s)", base, umid);
880 return title;