2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include "linux/irqreturn.h"
8 #include "linux/sched.h"
9 #include "linux/slab.h"
13 #include "kern_util.h"
16 #define LINE_BUFSIZE 4096
18 static irqreturn_t line_interrupt(int irq, void *data)
20 struct chan *chan = data;
21 struct line *line = chan->line;
24 chan_interrupt(line, line->tty, irq);
29 * Returns the free space inside the ring buffer of this line.
31 * Should be called while holding line->lock (this does not modify data).
33 static int write_room(struct line *line)
37 if (line->buffer == NULL)
38 return LINE_BUFSIZE - 1;
40 /* This is for the case where the buffer is wrapped! */
41 n = line->head - line->tail;
44 n += LINE_BUFSIZE; /* The other case */
48 int line_write_room(struct tty_struct *tty)
50 struct line *line = tty->driver_data;
54 spin_lock_irqsave(&line->lock, flags);
55 room = write_room(line);
56 spin_unlock_irqrestore(&line->lock, flags);
61 int line_chars_in_buffer(struct tty_struct *tty)
63 struct line *line = tty->driver_data;
67 spin_lock_irqsave(&line->lock, flags);
68 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
69 ret = LINE_BUFSIZE - (write_room(line) + 1);
70 spin_unlock_irqrestore(&line->lock, flags);
76 * This copies the content of buf into the circular buffer associated with
78 * The return value is the number of characters actually copied, i.e. the ones
79 * for which there was space: this function is not supposed to ever flush out
80 * the circular buffer.
82 * Must be called while holding line->lock!
84 static int buffer_data(struct line *line, const char *buf, int len)
88 if (line->buffer == NULL) {
89 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
90 if (line->buffer == NULL) {
91 printk(KERN_ERR "buffer_data - atomic allocation "
95 line->head = line->buffer;
96 line->tail = line->buffer;
99 room = write_room(line);
100 len = (len > room) ? room : len;
102 end = line->buffer + LINE_BUFSIZE - line->tail;
105 memcpy(line->tail, buf, len);
109 /* The circular buffer is wrapping */
110 memcpy(line->tail, buf, end);
112 memcpy(line->buffer, buf, len - end);
113 line->tail = line->buffer + len - end;
120 * Flushes the ring buffer to the output channels. That is, write_chan is
121 * called, passing it line->head as buffer, and an appropriate count.
123 * On exit, returns 1 when the buffer is empty,
124 * 0 when the buffer is not empty on exit,
125 * and -errno when an error occurred.
127 * Must be called while holding line->lock!*/
128 static int flush_buffer(struct line *line)
132 if ((line->buffer == NULL) || (line->head == line->tail))
135 if (line->tail < line->head) {
136 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
137 count = line->buffer + LINE_BUFSIZE - line->head;
139 n = write_chan(line->chan_out, line->head, count,
140 line->driver->write_irq);
145 * We have flushed from ->head to buffer end, now we
146 * must flush only from the beginning to ->tail.
148 line->head = line->buffer;
155 count = line->tail - line->head;
156 n = write_chan(line->chan_out, line->head, count,
157 line->driver->write_irq);
163 return line->head == line->tail;
166 void line_flush_buffer(struct tty_struct *tty)
168 struct line *line = tty->driver_data;
171 spin_lock_irqsave(&line->lock, flags);
173 spin_unlock_irqrestore(&line->lock, flags);
177 * We map both ->flush_chars and ->put_char (which go in pair) onto
178 * ->flush_buffer and ->write. Hope it's not that bad.
180 void line_flush_chars(struct tty_struct *tty)
182 line_flush_buffer(tty);
185 int line_put_char(struct tty_struct *tty, unsigned char ch)
187 return line_write(tty, &ch, sizeof(ch));
190 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
192 struct line *line = tty->driver_data;
196 spin_lock_irqsave(&line->lock, flags);
197 if (line->head != line->tail)
198 ret = buffer_data(line, buf, len);
200 n = write_chan(line->chan_out, buf, len,
201 line->driver->write_irq);
210 ret += buffer_data(line, buf + n, len);
213 spin_unlock_irqrestore(&line->lock, flags);
217 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
222 static const struct {
227 /* don't print these, they flood the log ... */
228 { TCGETS, NULL, "TCGETS" },
229 { TCSETS, NULL, "TCSETS" },
230 { TCSETSW, NULL, "TCSETSW" },
231 { TCFLSH, NULL, "TCFLSH" },
232 { TCSBRK, NULL, "TCSBRK" },
234 /* general tty stuff */
235 { TCSETSF, KERN_DEBUG, "TCSETSF" },
236 { TCGETA, KERN_DEBUG, "TCGETA" },
237 { TIOCMGET, KERN_DEBUG, "TIOCMGET" },
238 { TCSBRKP, KERN_DEBUG, "TCSBRKP" },
239 { TIOCMSET, KERN_DEBUG, "TIOCMSET" },
241 /* linux-specific ones */
242 { TIOCLINUX, KERN_INFO, "TIOCLINUX" },
243 { KDGKBMODE, KERN_INFO, "KDGKBMODE" },
244 { KDGKBTYPE, KERN_INFO, "KDGKBTYPE" },
245 { KDSIGACCEPT, KERN_INFO, "KDSIGACCEPT" },
248 int line_ioctl(struct tty_struct *tty, unsigned int cmd,
269 /* Note: these are out of date as we now have TCGETS2 etc but this
270 whole lot should probably go away */
295 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
296 if (cmd == tty_ioctls[i].cmd)
298 if (i == ARRAY_SIZE(tty_ioctls)) {
299 printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
300 __func__, tty->name, cmd);
308 void line_throttle(struct tty_struct *tty)
310 struct line *line = tty->driver_data;
312 deactivate_chan(line->chan_in, line->driver->read_irq);
316 void line_unthrottle(struct tty_struct *tty)
318 struct line *line = tty->driver_data;
321 chan_interrupt(line, tty, line->driver->read_irq);
324 * Maybe there is enough stuff pending that calling the interrupt
325 * throttles us again. In this case, line->throttled will be 1
326 * again and we shouldn't turn the interrupt back on.
328 if (!line->throttled)
329 reactivate_chan(line->chan_in, line->driver->read_irq);
332 static irqreturn_t line_write_interrupt(int irq, void *data)
334 struct chan *chan = data;
335 struct line *line = chan->line;
336 struct tty_struct *tty = line->tty;
340 * Interrupts are disabled here because genirq keep irqs disabled when
341 * calling the action handler.
344 spin_lock(&line->lock);
345 err = flush_buffer(line);
347 spin_unlock(&line->lock);
349 } else if (err < 0) {
350 line->head = line->buffer;
351 line->tail = line->buffer;
353 spin_unlock(&line->lock);
362 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
364 const struct line_driver *driver = line->driver;
365 int err = 0, flags = IRQF_SHARED | IRQF_SAMPLE_RANDOM;
368 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
369 line_interrupt, flags,
370 driver->read_irq_name, data);
374 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
375 line_write_interrupt, flags,
376 driver->write_irq_name, data);
381 * Normally, a driver like this can rely mostly on the tty layer
382 * locking, particularly when it comes to the driver structure.
383 * However, in this case, mconsole requests can come in "from the
384 * side", and race with opens and closes.
386 * mconsole config requests will want to be sure the device isn't in
387 * use, and get_config, open, and close will want a stable
388 * configuration. The checking and modification of the configuration
389 * is done under a spinlock. Checking whether the device is in use is
390 * line->tty->count > 1, also under the spinlock.
392 * line->count serves to decide whether the device should be enabled or
393 * disabled on the host. If it's equal to 0, then we are doing the
394 * first open or last close. Otherwise, open and close just return.
397 int line_open(struct line *lines, struct tty_struct *tty)
399 struct line *line = &lines[tty->index];
402 mutex_lock(&line->count_lock);
410 BUG_ON(tty->driver_data);
411 tty->driver_data = line;
414 err = enable_chan(line);
415 if (err) /* line_close() will be called by our caller */
419 chan_enable_winch(line->chan_out, tty);
423 chan_window_size(line, &tty->winsize.ws_row,
424 &tty->winsize.ws_col);
426 mutex_unlock(&line->count_lock);
430 static void unregister_winch(struct tty_struct *tty);
432 void line_close(struct tty_struct *tty, struct file * filp)
434 struct line *line = tty->driver_data;
437 * If line_open fails (and tty->driver_data is never set),
438 * tty_open will call line_close. So just return in this case.
443 /* We ignore the error anyway! */
446 mutex_lock(&line->count_lock);
447 BUG_ON(!line->valid);
453 tty->driver_data = NULL;
456 unregister_winch(tty);
461 mutex_unlock(&line->count_lock);
464 void close_lines(struct line *lines, int nlines)
468 for(i = 0; i < nlines; i++)
469 close_chan(&lines[i]);
472 int setup_one_line(struct line *lines, int n, char *init,
473 const struct chan_opts *opts, char **error_out)
475 struct line *line = &lines[n];
476 struct tty_driver *driver = line->driver->driver;
479 mutex_lock(&line->count_lock);
482 *error_out = "Device is already open";
486 if (!strcmp(init, "none")) {
489 kfree(line->init_str);
490 tty_unregister_device(driver, n);
491 parse_chan_pair(NULL, line, n, opts, error_out);
495 char *new = kstrdup(init, GFP_KERNEL);
497 *error_out = "Failed to allocate memory";
501 tty_unregister_device(driver, n);
502 kfree(line->init_str);
504 line->init_str = new;
506 err = parse_chan_pair(new, line, n, opts, error_out);
508 struct device *d = tty_register_device(driver, n, NULL);
510 *error_out = "Failed to register device";
512 parse_chan_pair(NULL, line, n, opts, error_out);
516 line->init_str = NULL;
522 mutex_unlock(&line->count_lock);
527 * Common setup code for both startup command line and mconsole initialization.
528 * @lines contains the array (of size @num) to modify;
529 * @init is the setup string;
530 * @error_out is an error string in the case of failure;
533 int line_setup(char **conf, unsigned int num, char **def,
534 char *init, char *name)
540 * We said con=/ssl= instead of con#=, so we are configuring all
546 unsigned n = simple_strtoul(init, &end, 0);
549 error = "Couldn't parse device number";
553 error = "Device number out of range";
561 printk(KERN_ERR "Failed to set up %s with "
562 "configuration string \"%s\" : %s\n", name, init, error);
566 int line_config(struct line *lines, unsigned int num, char *str,
567 const struct chan_opts *opts, char **error_out)
573 *error_out = "Can't configure all devices from mconsole";
577 n = simple_strtoul(str, &end, 0);
579 *error_out = "Couldn't parse device number";
583 *error_out = "Device number out of range";
587 return setup_one_line(lines, n, end, opts, error_out);
590 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
591 int size, char **error_out)
597 dev = simple_strtoul(name, &end, 0);
598 if ((*end != '\0') || (end == name)) {
599 *error_out = "line_get_config failed to parse device number";
603 if ((dev < 0) || (dev >= num)) {
604 *error_out = "device number out of range";
610 mutex_lock(&line->count_lock);
612 CONFIG_CHUNK(str, size, n, "none", 1);
613 else if (line->tty == NULL)
614 CONFIG_CHUNK(str, size, n, line->init_str, 1);
615 else n = chan_config_string(line, str, size, error_out);
616 mutex_unlock(&line->count_lock);
621 int line_id(char **str, int *start_out, int *end_out)
626 n = simple_strtoul(*str, &end, 0);
627 if ((*end != '\0') || (end == *str))
636 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
639 *error_out = "Device number out of range";
642 return setup_one_line(lines, n, "none", NULL, error_out);
645 int register_lines(struct line_driver *line_driver,
646 const struct tty_operations *ops,
647 struct line *lines, int nlines)
649 struct tty_driver *driver = alloc_tty_driver(nlines);
656 driver->driver_name = line_driver->name;
657 driver->name = line_driver->device_name;
658 driver->major = line_driver->major;
659 driver->minor_start = line_driver->minor_start;
660 driver->type = line_driver->type;
661 driver->subtype = line_driver->subtype;
662 driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
663 driver->init_termios = tty_std_termios;
665 for (i = 0; i < nlines; i++) {
666 spin_lock_init(&lines[i].lock);
667 mutex_init(&lines[i].count_lock);
668 lines[i].driver = line_driver;
669 INIT_LIST_HEAD(&lines[i].chan_list);
671 tty_set_operations(driver, ops);
673 err = tty_register_driver(driver);
675 printk(KERN_ERR "register_lines : can't register %s driver\n",
677 put_tty_driver(driver);
681 line_driver->driver = driver;
682 mconsole_register_dev(&line_driver->mc);
686 static DEFINE_SPINLOCK(winch_handler_lock);
687 static LIST_HEAD(winch_handlers);
690 struct list_head list;
694 struct tty_struct *tty;
696 struct work_struct work;
699 static void __free_winch(struct work_struct *work)
701 struct winch *winch = container_of(work, struct winch, work);
702 um_free_irq(WINCH_IRQ, winch);
704 if (winch->pid != -1)
705 os_kill_process(winch->pid, 1);
706 if (winch->stack != 0)
707 free_stack(winch->stack, 0);
711 static void free_winch(struct winch *winch)
717 list_del(&winch->list);
718 __free_winch(&winch->work);
721 static irqreturn_t winch_interrupt(int irq, void *data)
723 struct winch *winch = data;
724 struct tty_struct *tty;
731 err = generic_read(fd, &c, NULL);
733 if (err != -EAGAIN) {
735 list_del(&winch->list);
737 printk(KERN_ERR "winch_interrupt : "
738 "read failed, errno = %d\n", -err);
739 printk(KERN_ERR "fd %d is losing SIGWINCH "
740 "support\n", winch->tty_fd);
741 INIT_WORK(&winch->work, __free_winch);
742 schedule_work(&winch->work);
750 line = tty->driver_data;
752 chan_window_size(line, &tty->winsize.ws_row,
753 &tty->winsize.ws_col);
754 kill_pgrp(tty->pgrp, SIGWINCH, 1);
759 reactivate_fd(winch->fd, WINCH_IRQ);
763 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
768 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
770 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
774 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
781 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
782 IRQF_SHARED | IRQF_SAMPLE_RANDOM,
783 "winch", winch) < 0) {
784 printk(KERN_ERR "register_winch_irq - failed to register "
789 spin_lock(&winch_handler_lock);
790 list_add(&winch->list, &winch_handlers);
791 spin_unlock(&winch_handler_lock);
798 os_kill_process(pid, 1);
801 free_stack(stack, 0);
804 static void unregister_winch(struct tty_struct *tty)
806 struct list_head *ele, *next;
809 spin_lock(&winch_handler_lock);
811 list_for_each_safe(ele, next, &winch_handlers) {
812 winch = list_entry(ele, struct winch, list);
813 if (winch->tty == tty) {
818 spin_unlock(&winch_handler_lock);
821 static void winch_cleanup(void)
823 struct list_head *ele, *next;
826 spin_lock(&winch_handler_lock);
828 list_for_each_safe(ele, next, &winch_handlers) {
829 winch = list_entry(ele, struct winch, list);
833 spin_unlock(&winch_handler_lock);
835 __uml_exitcall(winch_cleanup);
837 char *add_xterm_umid(char *base)
846 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
847 title = kmalloc(len, GFP_KERNEL);
849 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
853 snprintf(title, len, "%s (%s)", base, umid);