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, irq);
30 * Returns the free space inside the ring buffer of this line.
32 * Should be called while holding line->lock (this does not modify data).
34 static int write_room(struct line *line)
38 if (line->buffer == NULL)
39 return LINE_BUFSIZE - 1;
41 /* This is for the case where the buffer is wrapped! */
42 n = line->head - line->tail;
45 n += LINE_BUFSIZE; /* The other case */
49 int line_write_room(struct tty_struct *tty)
51 struct line *line = tty->driver_data;
55 spin_lock_irqsave(&line->lock, flags);
56 room = write_room(line);
57 spin_unlock_irqrestore(&line->lock, flags);
62 int line_chars_in_buffer(struct tty_struct *tty)
64 struct line *line = tty->driver_data;
68 spin_lock_irqsave(&line->lock, flags);
69 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
70 ret = LINE_BUFSIZE - (write_room(line) + 1);
71 spin_unlock_irqrestore(&line->lock, flags);
77 * This copies the content of buf into the circular buffer associated with
79 * The return value is the number of characters actually copied, i.e. the ones
80 * for which there was space: this function is not supposed to ever flush out
81 * the circular buffer.
83 * Must be called while holding line->lock!
85 static int buffer_data(struct line *line, const char *buf, int len)
89 if (line->buffer == NULL) {
90 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
91 if (line->buffer == NULL) {
92 printk(KERN_ERR "buffer_data - atomic allocation "
96 line->head = line->buffer;
97 line->tail = line->buffer;
100 room = write_room(line);
101 len = (len > room) ? room : len;
103 end = line->buffer + LINE_BUFSIZE - line->tail;
106 memcpy(line->tail, buf, len);
110 /* The circular buffer is wrapping */
111 memcpy(line->tail, buf, end);
113 memcpy(line->buffer, buf, len - end);
114 line->tail = line->buffer + len - end;
121 * Flushes the ring buffer to the output channels. That is, write_chan is
122 * called, passing it line->head as buffer, and an appropriate count.
124 * On exit, returns 1 when the buffer is empty,
125 * 0 when the buffer is not empty on exit,
126 * and -errno when an error occurred.
128 * Must be called while holding line->lock!*/
129 static int flush_buffer(struct line *line)
133 if ((line->buffer == NULL) || (line->head == line->tail))
136 if (line->tail < line->head) {
137 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
138 count = line->buffer + LINE_BUFSIZE - line->head;
140 n = write_chan(line->chan_out, line->head, count,
141 line->driver->write_irq);
146 * We have flushed from ->head to buffer end, now we
147 * must flush only from the beginning to ->tail.
149 line->head = line->buffer;
156 count = line->tail - line->head;
157 n = write_chan(line->chan_out, line->head, count,
158 line->driver->write_irq);
164 return line->head == line->tail;
167 void line_flush_buffer(struct tty_struct *tty)
169 struct line *line = tty->driver_data;
172 spin_lock_irqsave(&line->lock, flags);
174 spin_unlock_irqrestore(&line->lock, flags);
178 * We map both ->flush_chars and ->put_char (which go in pair) onto
179 * ->flush_buffer and ->write. Hope it's not that bad.
181 void line_flush_chars(struct tty_struct *tty)
183 line_flush_buffer(tty);
186 int line_put_char(struct tty_struct *tty, unsigned char ch)
188 return line_write(tty, &ch, sizeof(ch));
191 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
193 struct line *line = tty->driver_data;
197 spin_lock_irqsave(&line->lock, flags);
198 if (line->head != line->tail)
199 ret = buffer_data(line, buf, len);
201 n = write_chan(line->chan_out, buf, len,
202 line->driver->write_irq);
211 ret += buffer_data(line, buf + n, len);
214 spin_unlock_irqrestore(&line->lock, flags);
218 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
223 void line_throttle(struct tty_struct *tty)
225 struct line *line = tty->driver_data;
227 deactivate_chan(line->chan_in, line->driver->read_irq);
231 void line_unthrottle(struct tty_struct *tty)
233 struct line *line = tty->driver_data;
236 chan_interrupt(line, line->driver->read_irq);
239 * Maybe there is enough stuff pending that calling the interrupt
240 * throttles us again. In this case, line->throttled will be 1
241 * again and we shouldn't turn the interrupt back on.
243 if (!line->throttled)
244 reactivate_chan(line->chan_in, line->driver->read_irq);
247 static irqreturn_t line_write_interrupt(int irq, void *data)
249 struct chan *chan = data;
250 struct line *line = chan->line;
251 struct tty_struct *tty;
255 * Interrupts are disabled here because genirq keep irqs disabled when
256 * calling the action handler.
259 spin_lock(&line->lock);
260 err = flush_buffer(line);
262 spin_unlock(&line->lock);
264 } else if (err < 0) {
265 line->head = line->buffer;
266 line->tail = line->buffer;
268 spin_unlock(&line->lock);
270 tty = tty_port_tty_get(&line->port);
280 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
282 const struct line_driver *driver = line->driver;
286 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
287 line_interrupt, IRQF_SHARED,
288 driver->read_irq_name, data);
292 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
293 line_write_interrupt, IRQF_SHARED,
294 driver->write_irq_name, data);
298 static int line_activate(struct tty_port *port, struct tty_struct *tty)
301 struct line *line = tty->driver_data;
303 ret = enable_chan(line);
308 chan_enable_winch(line->chan_out, port);
312 chan_window_size(line, &tty->winsize.ws_row,
313 &tty->winsize.ws_col);
318 static void unregister_winch(struct tty_struct *tty);
320 static void line_destruct(struct tty_port *port)
322 struct tty_struct *tty = tty_port_tty_get(port);
323 struct line *line = tty->driver_data;
326 unregister_winch(tty);
331 static const struct tty_port_operations line_port_ops = {
332 .activate = line_activate,
333 .destruct = line_destruct,
336 int line_open(struct tty_struct *tty, struct file *filp)
338 struct line *line = tty->driver_data;
340 return tty_port_open(&line->port, tty, filp);
343 int line_install(struct tty_driver *driver, struct tty_struct *tty,
348 ret = tty_standard_install(driver, tty);
352 tty->driver_data = line;
357 void line_close(struct tty_struct *tty, struct file * filp)
359 struct line *line = tty->driver_data;
361 tty_port_close(&line->port, tty, filp);
364 void line_hangup(struct tty_struct *tty)
366 struct line *line = tty->driver_data;
368 tty_port_hangup(&line->port);
371 void close_lines(struct line *lines, int nlines)
375 for(i = 0; i < nlines; i++)
376 close_chan(&lines[i]);
379 int setup_one_line(struct line *lines, int n, char *init,
380 const struct chan_opts *opts, char **error_out)
382 struct line *line = &lines[n];
383 struct tty_driver *driver = line->driver->driver;
386 if (line->port.count) {
387 *error_out = "Device is already open";
391 if (!strcmp(init, "none")) {
394 kfree(line->init_str);
395 tty_unregister_device(driver, n);
396 parse_chan_pair(NULL, line, n, opts, error_out);
400 char *new = kstrdup(init, GFP_KERNEL);
402 *error_out = "Failed to allocate memory";
406 tty_unregister_device(driver, n);
407 kfree(line->init_str);
409 line->init_str = new;
411 err = parse_chan_pair(new, line, n, opts, error_out);
413 struct device *d = tty_port_register_device(&line->port,
416 *error_out = "Failed to register device";
418 parse_chan_pair(NULL, line, n, opts, error_out);
422 line->init_str = NULL;
432 * Common setup code for both startup command line and mconsole initialization.
433 * @lines contains the array (of size @num) to modify;
434 * @init is the setup string;
435 * @error_out is an error string in the case of failure;
438 int line_setup(char **conf, unsigned int num, char **def,
439 char *init, char *name)
445 * We said con=/ssl= instead of con#=, so we are configuring all
451 unsigned n = simple_strtoul(init, &end, 0);
454 error = "Couldn't parse device number";
458 error = "Device number out of range";
466 printk(KERN_ERR "Failed to set up %s with "
467 "configuration string \"%s\" : %s\n", name, init, error);
471 int line_config(struct line *lines, unsigned int num, char *str,
472 const struct chan_opts *opts, char **error_out)
478 *error_out = "Can't configure all devices from mconsole";
482 n = simple_strtoul(str, &end, 0);
484 *error_out = "Couldn't parse device number";
488 *error_out = "Device number out of range";
492 return setup_one_line(lines, n, end, opts, error_out);
495 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
496 int size, char **error_out)
502 dev = simple_strtoul(name, &end, 0);
503 if ((*end != '\0') || (end == name)) {
504 *error_out = "line_get_config failed to parse device number";
508 if ((dev < 0) || (dev >= num)) {
509 *error_out = "device number out of range";
516 CONFIG_CHUNK(str, size, n, "none", 1);
518 struct tty_struct *tty = tty_port_tty_get(&line->port);
520 CONFIG_CHUNK(str, size, n, line->init_str, 1);
522 n = chan_config_string(line, str, size, error_out);
530 int line_id(char **str, int *start_out, int *end_out)
535 n = simple_strtoul(*str, &end, 0);
536 if ((*end != '\0') || (end == *str))
545 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
548 *error_out = "Device number out of range";
551 return setup_one_line(lines, n, "none", NULL, error_out);
554 int register_lines(struct line_driver *line_driver,
555 const struct tty_operations *ops,
556 struct line *lines, int nlines)
558 struct tty_driver *driver = alloc_tty_driver(nlines);
565 driver->driver_name = line_driver->name;
566 driver->name = line_driver->device_name;
567 driver->major = line_driver->major;
568 driver->minor_start = line_driver->minor_start;
569 driver->type = line_driver->type;
570 driver->subtype = line_driver->subtype;
571 driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
572 driver->init_termios = tty_std_termios;
574 for (i = 0; i < nlines; i++) {
575 tty_port_init(&lines[i].port);
576 lines[i].port.ops = &line_port_ops;
577 spin_lock_init(&lines[i].lock);
578 lines[i].driver = line_driver;
579 INIT_LIST_HEAD(&lines[i].chan_list);
581 tty_set_operations(driver, ops);
583 err = tty_register_driver(driver);
585 printk(KERN_ERR "register_lines : can't register %s driver\n",
587 put_tty_driver(driver);
588 for (i = 0; i < nlines; i++)
589 tty_port_destroy(&lines[i].port);
593 line_driver->driver = driver;
594 mconsole_register_dev(&line_driver->mc);
598 static DEFINE_SPINLOCK(winch_handler_lock);
599 static LIST_HEAD(winch_handlers);
602 struct list_head list;
606 struct tty_port *port;
608 struct work_struct work;
611 static void __free_winch(struct work_struct *work)
613 struct winch *winch = container_of(work, struct winch, work);
614 um_free_irq(WINCH_IRQ, winch);
616 if (winch->pid != -1)
617 os_kill_process(winch->pid, 1);
618 if (winch->stack != 0)
619 free_stack(winch->stack, 0);
623 static void free_winch(struct winch *winch)
629 list_del(&winch->list);
630 __free_winch(&winch->work);
633 static irqreturn_t winch_interrupt(int irq, void *data)
635 struct winch *winch = data;
636 struct tty_struct *tty;
643 err = generic_read(fd, &c, NULL);
645 if (err != -EAGAIN) {
647 list_del(&winch->list);
649 printk(KERN_ERR "winch_interrupt : "
650 "read failed, errno = %d\n", -err);
651 printk(KERN_ERR "fd %d is losing SIGWINCH "
652 "support\n", winch->tty_fd);
653 INIT_WORK(&winch->work, __free_winch);
654 schedule_work(&winch->work);
660 tty = tty_port_tty_get(winch->port);
662 line = tty->driver_data;
664 chan_window_size(line, &tty->winsize.ws_row,
665 &tty->winsize.ws_col);
666 kill_pgrp(tty->pgrp, SIGWINCH, 1);
672 reactivate_fd(winch->fd, WINCH_IRQ);
676 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_port *port,
681 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
683 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
687 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
694 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
695 IRQF_SHARED, "winch", winch) < 0) {
696 printk(KERN_ERR "register_winch_irq - failed to register "
701 spin_lock(&winch_handler_lock);
702 list_add(&winch->list, &winch_handlers);
703 spin_unlock(&winch_handler_lock);
710 os_kill_process(pid, 1);
713 free_stack(stack, 0);
716 static void unregister_winch(struct tty_struct *tty)
718 struct list_head *ele, *next;
720 struct tty_struct *wtty;
722 spin_lock(&winch_handler_lock);
724 list_for_each_safe(ele, next, &winch_handlers) {
725 winch = list_entry(ele, struct winch, list);
726 wtty = tty_port_tty_get(winch->port);
733 spin_unlock(&winch_handler_lock);
736 static void winch_cleanup(void)
738 struct list_head *ele, *next;
741 spin_lock(&winch_handler_lock);
743 list_for_each_safe(ele, next, &winch_handlers) {
744 winch = list_entry(ele, struct winch, list);
748 spin_unlock(&winch_handler_lock);
750 __uml_exitcall(winch_cleanup);
752 char *add_xterm_umid(char *base)
761 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
762 title = kmalloc(len, GFP_KERNEL);
764 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
768 snprintf(title, len, "%s (%s)", base, umid);