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"
10 #include "chan_kern.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->chan_list, &line->task, line->tty, irq);
28 static void line_timer_cb(struct work_struct *work)
30 struct line *line = container_of(work, struct line, task.work);
33 chan_interrupt(&line->chan_list, &line->task, line->tty,
34 line->driver->read_irq);
38 * Returns the free space inside the ring buffer of this line.
40 * Should be called while holding line->lock (this does not modify data).
42 static int write_room(struct line *line)
46 if (line->buffer == NULL)
47 return LINE_BUFSIZE - 1;
49 /* This is for the case where the buffer is wrapped! */
50 n = line->head - line->tail;
53 n += LINE_BUFSIZE; /* The other case */
57 int line_write_room(struct tty_struct *tty)
59 struct line *line = tty->driver_data;
63 spin_lock_irqsave(&line->lock, flags);
64 room = write_room(line);
65 spin_unlock_irqrestore(&line->lock, flags);
70 int line_chars_in_buffer(struct tty_struct *tty)
72 struct line *line = tty->driver_data;
76 spin_lock_irqsave(&line->lock, flags);
77 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
78 ret = LINE_BUFSIZE - (write_room(line) + 1);
79 spin_unlock_irqrestore(&line->lock, flags);
85 * This copies the content of buf into the circular buffer associated with
87 * The return value is the number of characters actually copied, i.e. the ones
88 * for which there was space: this function is not supposed to ever flush out
89 * the circular buffer.
91 * Must be called while holding line->lock!
93 static int buffer_data(struct line *line, const char *buf, int len)
97 if (line->buffer == NULL) {
98 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
99 if (line->buffer == NULL) {
100 printk(KERN_ERR "buffer_data - atomic allocation "
104 line->head = line->buffer;
105 line->tail = line->buffer;
108 room = write_room(line);
109 len = (len > room) ? room : len;
111 end = line->buffer + LINE_BUFSIZE - line->tail;
114 memcpy(line->tail, buf, len);
118 /* The circular buffer is wrapping */
119 memcpy(line->tail, buf, end);
121 memcpy(line->buffer, buf, len - end);
122 line->tail = line->buffer + len - end;
129 * Flushes the ring buffer to the output channels. That is, write_chan is
130 * called, passing it line->head as buffer, and an appropriate count.
132 * On exit, returns 1 when the buffer is empty,
133 * 0 when the buffer is not empty on exit,
134 * and -errno when an error occurred.
136 * Must be called while holding line->lock!*/
137 static int flush_buffer(struct line *line)
141 if ((line->buffer == NULL) || (line->head == line->tail))
144 if (line->tail < line->head) {
145 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
146 count = line->buffer + LINE_BUFSIZE - line->head;
148 n = write_chan(&line->chan_list, line->head, count,
149 line->driver->write_irq);
154 * We have flushed from ->head to buffer end, now we
155 * must flush only from the beginning to ->tail.
157 line->head = line->buffer;
164 count = line->tail - line->head;
165 n = write_chan(&line->chan_list, line->head, count,
166 line->driver->write_irq);
172 return line->head == line->tail;
175 void line_flush_buffer(struct tty_struct *tty)
177 struct line *line = tty->driver_data;
180 spin_lock_irqsave(&line->lock, flags);
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;
205 spin_lock_irqsave(&line->lock, flags);
206 if (line->head != line->tail)
207 ret = buffer_data(line, buf, len);
209 n = write_chan(&line->chan_list, buf, len,
210 line->driver->write_irq);
219 ret += buffer_data(line, buf + n, len);
222 spin_unlock_irqrestore(&line->lock, flags);
226 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
231 static const struct {
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, unsigned int cmd,
278 /* Note: these are out of date as we now have TCGETS2 etc but this
279 whole lot should probably go away */
304 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
305 if (cmd == tty_ioctls[i].cmd)
307 if (i == ARRAY_SIZE(tty_ioctls)) {
308 printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
309 __func__, tty->name, cmd);
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);
325 void line_unthrottle(struct tty_struct *tty)
327 struct line *line = tty->driver_data;
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;
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);
358 } else if (err < 0) {
359 line->head = line->buffer;
360 line->tail = line->buffer;
362 spin_unlock(&line->lock);
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;
377 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
378 line_interrupt, flags,
379 driver->read_irq_name, data);
383 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
384 line_write_interrupt, flags,
385 driver->write_irq_name, data);
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 * line->count serves to decide whether the device should be enabled or
403 * disabled on the host. If it's equal to 0, 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];
412 spin_lock(&line->count_lock);
420 BUG_ON(tty->driver_data);
421 tty->driver_data = line;
424 spin_unlock(&line->count_lock);
425 err = enable_chan(line);
426 if (err) /* line_close() will be called by our caller */
429 INIT_DELAYED_WORK(&line->task, line_timer_cb);
432 chan_enable_winch(&line->chan_list, tty);
436 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
437 &tty->winsize.ws_col);
442 spin_unlock(&line->count_lock);
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.
459 /* We ignore the error anyway! */
462 spin_lock(&line->count_lock);
463 BUG_ON(!line->valid);
469 tty->driver_data = NULL;
471 spin_unlock(&line->count_lock);
474 unregister_winch(tty);
481 spin_unlock(&line->count_lock);
484 void close_lines(struct line *lines, int nlines)
488 for(i = 0; i < nlines; i++)
489 close_chan(&lines[i].chan_list, 0);
492 static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
495 struct line *line = &lines[n];
498 spin_lock(&line->count_lock);
501 *error_out = "Device is already open";
505 if (line->init_pri <= init_prio) {
506 line->init_pri = init_prio;
507 if (!strcmp(init, "none"))
510 line->init_str = init;
516 spin_unlock(&line->count_lock);
521 * Common setup code for both startup command line and mconsole initialization.
522 * @lines contains the array (of size @num) to modify;
523 * @init is the setup string;
524 * @error_out is an error string in the case of failure;
527 int line_setup(struct line *lines, unsigned int num, char *init,
535 * We said con=/ssl= instead of con#=, so we are configuring all
541 n = simple_strtoul(init, &end, 0);
543 *error_out = "Couldn't parse device number";
550 if (n >= (signed int) num) {
551 *error_out = "Device number out of range";
555 err = setup_one_line(lines, n, init, INIT_ONE, error_out);
560 for(i = 0; i < num; i++) {
561 err = setup_one_line(lines, i, init, INIT_ALL,
567 return n == -1 ? num : n;
570 int line_config(struct line *lines, unsigned int num, char *str,
571 const struct chan_opts *opts, char **error_out)
578 *error_out = "Can't configure all devices from mconsole";
582 new = kstrdup(str, GFP_KERNEL);
584 *error_out = "Failed to allocate memory";
587 n = line_setup(lines, num, new, error_out);
592 return parse_chan_pair(line->init_str, line, n, opts, error_out);
595 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
596 int size, char **error_out)
602 dev = simple_strtoul(name, &end, 0);
603 if ((*end != '\0') || (end == name)) {
604 *error_out = "line_get_config failed to parse device number";
608 if ((dev < 0) || (dev >= num)) {
609 *error_out = "device number out of range";
615 spin_lock(&line->count_lock);
617 CONFIG_CHUNK(str, size, n, "none", 1);
618 else if (line->tty == NULL)
619 CONFIG_CHUNK(str, size, n, line->init_str, 1);
620 else n = chan_config_string(&line->chan_list, str, size, error_out);
621 spin_unlock(&line->count_lock);
626 int line_id(char **str, int *start_out, int *end_out)
631 n = simple_strtoul(*str, &end, 0);
632 if ((*end != '\0') || (end == *str))
641 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
644 char config[sizeof("conxxxx=none\0")];
646 sprintf(config, "%d=none", n);
647 err = line_setup(lines, num, config, error_out);
653 struct tty_driver *register_lines(struct line_driver *line_driver,
654 const struct tty_operations *ops,
655 struct line *lines, int nlines)
658 struct tty_driver *driver = alloc_tty_driver(nlines);
663 driver->driver_name = line_driver->name;
664 driver->name = line_driver->device_name;
665 driver->major = line_driver->major;
666 driver->minor_start = line_driver->minor_start;
667 driver->type = line_driver->type;
668 driver->subtype = line_driver->subtype;
669 driver->flags = TTY_DRIVER_REAL_RAW;
670 driver->init_termios = tty_std_termios;
671 tty_set_operations(driver, ops);
673 if (tty_register_driver(driver)) {
674 printk(KERN_ERR "register_lines : can't register %s driver\n",
676 put_tty_driver(driver);
680 for(i = 0; i < nlines; i++) {
682 tty_unregister_device(driver, i);
685 mconsole_register_dev(&line_driver->mc);
689 static DEFINE_SPINLOCK(winch_handler_lock);
690 static LIST_HEAD(winch_handlers);
692 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
698 for(i = 0; i < nlines; i++) {
700 INIT_LIST_HEAD(&line->chan_list);
702 if (line->init_str == NULL)
705 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
706 if (line->init_str == NULL)
707 printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
709 if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
710 printk(KERN_ERR "parse_chan_pair failed for "
711 "device %d : %s\n", i, error);
718 struct list_head list;
722 struct tty_struct *tty;
724 struct work_struct work;
727 static void __free_winch(struct work_struct *work)
729 struct winch *winch = container_of(work, struct winch, work);
730 free_irq(WINCH_IRQ, winch);
732 if (winch->pid != -1)
733 os_kill_process(winch->pid, 1);
734 if (winch->stack != 0)
735 free_stack(winch->stack, 0);
739 static void free_winch(struct winch *winch)
745 list_del(&winch->list);
746 __free_winch(&winch->work);
749 static irqreturn_t winch_interrupt(int irq, void *data)
751 struct winch *winch = data;
752 struct tty_struct *tty;
759 err = generic_read(fd, &c, NULL);
761 if (err != -EAGAIN) {
763 list_del(&winch->list);
765 printk(KERN_ERR "winch_interrupt : "
766 "read failed, errno = %d\n", -err);
767 printk(KERN_ERR "fd %d is losing SIGWINCH "
768 "support\n", winch->tty_fd);
769 INIT_WORK(&winch->work, __free_winch);
770 schedule_work(&winch->work);
778 line = tty->driver_data;
780 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
781 &tty->winsize.ws_col);
782 kill_pgrp(tty->pgrp, SIGWINCH, 1);
787 reactivate_fd(winch->fd, WINCH_IRQ);
791 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
796 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
798 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
802 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
809 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
810 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
811 "winch", winch) < 0) {
812 printk(KERN_ERR "register_winch_irq - failed to register "
817 spin_lock(&winch_handler_lock);
818 list_add(&winch->list, &winch_handlers);
819 spin_unlock(&winch_handler_lock);
826 os_kill_process(pid, 1);
829 free_stack(stack, 0);
832 static void unregister_winch(struct tty_struct *tty)
834 struct list_head *ele, *next;
837 spin_lock(&winch_handler_lock);
839 list_for_each_safe(ele, next, &winch_handlers) {
840 winch = list_entry(ele, struct winch, list);
841 if (winch->tty == tty) {
846 spin_unlock(&winch_handler_lock);
849 static void winch_cleanup(void)
851 struct list_head *ele, *next;
854 spin_lock(&winch_handler_lock);
856 list_for_each_safe(ele, next, &winch_handlers) {
857 winch = list_entry(ele, struct winch, list);
861 spin_unlock(&winch_handler_lock);
863 __uml_exitcall(winch_cleanup);
865 char *add_xterm_umid(char *base)
874 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
875 title = kmalloc(len, GFP_KERNEL);
877 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
881 snprintf(title, len, "%s (%s)", base, umid);