1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 #include <linux/irqreturn.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
14 #include <kern_util.h>
17 #define LINE_BUFSIZE 4096
19 static irqreturn_t line_interrupt(int irq, void *data)
21 struct chan *chan = data;
22 struct line *line = chan->line;
25 chan_interrupt(line, irq);
31 * Returns the free space inside the ring buffer of this line.
33 * Should be called while holding line->lock (this does not modify data).
35 static int write_room(struct line *line)
39 if (line->buffer == NULL)
40 return LINE_BUFSIZE - 1;
42 /* This is for the case where the buffer is wrapped! */
43 n = line->head - line->tail;
46 n += LINE_BUFSIZE; /* The other case */
50 int line_write_room(struct tty_struct *tty)
52 struct line *line = tty->driver_data;
56 spin_lock_irqsave(&line->lock, flags);
57 room = write_room(line);
58 spin_unlock_irqrestore(&line->lock, flags);
63 int line_chars_in_buffer(struct tty_struct *tty)
65 struct line *line = tty->driver_data;
69 spin_lock_irqsave(&line->lock, flags);
70 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
71 ret = LINE_BUFSIZE - (write_room(line) + 1);
72 spin_unlock_irqrestore(&line->lock, flags);
78 * This copies the content of buf into the circular buffer associated with
80 * The return value is the number of characters actually copied, i.e. the ones
81 * for which there was space: this function is not supposed to ever flush out
82 * the circular buffer.
84 * Must be called while holding line->lock!
86 static int buffer_data(struct line *line, const char *buf, int len)
90 if (line->buffer == NULL) {
91 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
92 if (line->buffer == NULL) {
93 printk(KERN_ERR "buffer_data - atomic allocation "
97 line->head = line->buffer;
98 line->tail = line->buffer;
101 room = write_room(line);
102 len = (len > room) ? room : len;
104 end = line->buffer + LINE_BUFSIZE - line->tail;
107 memcpy(line->tail, buf, len);
111 /* The circular buffer is wrapping */
112 memcpy(line->tail, buf, end);
114 memcpy(line->buffer, buf, len - end);
115 line->tail = line->buffer + len - end;
122 * Flushes the ring buffer to the output channels. That is, write_chan is
123 * called, passing it line->head as buffer, and an appropriate count.
125 * On exit, returns 1 when the buffer is empty,
126 * 0 when the buffer is not empty on exit,
127 * and -errno when an error occurred.
129 * Must be called while holding line->lock!*/
130 static int flush_buffer(struct line *line)
134 if ((line->buffer == NULL) || (line->head == line->tail))
137 if (line->tail < line->head) {
138 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
139 count = line->buffer + LINE_BUFSIZE - line->head;
141 n = write_chan(line->chan_out, line->head, count,
142 line->driver->write_irq);
147 * We have flushed from ->head to buffer end, now we
148 * must flush only from the beginning to ->tail.
150 line->head = line->buffer;
157 count = line->tail - line->head;
158 n = write_chan(line->chan_out, line->head, count,
159 line->driver->write_irq);
165 return line->head == line->tail;
168 void line_flush_buffer(struct tty_struct *tty)
170 struct line *line = tty->driver_data;
173 spin_lock_irqsave(&line->lock, flags);
175 spin_unlock_irqrestore(&line->lock, flags);
179 * We map both ->flush_chars and ->put_char (which go in pair) onto
180 * ->flush_buffer and ->write. Hope it's not that bad.
182 void line_flush_chars(struct tty_struct *tty)
184 line_flush_buffer(tty);
187 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
189 struct line *line = tty->driver_data;
193 spin_lock_irqsave(&line->lock, flags);
194 if (line->head != line->tail)
195 ret = buffer_data(line, buf, len);
197 n = write_chan(line->chan_out, buf, len,
198 line->driver->write_irq);
207 ret += buffer_data(line, buf + n, len);
210 spin_unlock_irqrestore(&line->lock, flags);
214 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
219 void line_throttle(struct tty_struct *tty)
221 struct line *line = tty->driver_data;
223 deactivate_chan(line->chan_in, line->driver->read_irq);
227 void line_unthrottle(struct tty_struct *tty)
229 struct line *line = tty->driver_data;
232 chan_interrupt(line, line->driver->read_irq);
235 static irqreturn_t line_write_interrupt(int irq, void *data)
237 struct chan *chan = data;
238 struct line *line = chan->line;
242 * Interrupts are disabled here because genirq keep irqs disabled when
243 * calling the action handler.
246 spin_lock(&line->lock);
247 err = flush_buffer(line);
249 spin_unlock(&line->lock);
251 } else if ((err < 0) && (err != -EAGAIN)) {
252 line->head = line->buffer;
253 line->tail = line->buffer;
255 spin_unlock(&line->lock);
257 tty_port_tty_wakeup(&line->port);
262 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
264 const struct line_driver *driver = line->driver;
268 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
269 line_interrupt, IRQF_SHARED,
270 driver->read_irq_name, data);
274 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
275 line_write_interrupt, IRQF_SHARED,
276 driver->write_irq_name, data);
280 static int line_activate(struct tty_port *port, struct tty_struct *tty)
283 struct line *line = tty->driver_data;
285 ret = enable_chan(line);
290 chan_enable_winch(line->chan_out, port);
294 chan_window_size(line, &tty->winsize.ws_row,
295 &tty->winsize.ws_col);
300 static void unregister_winch(struct tty_struct *tty);
302 static void line_destruct(struct tty_port *port)
304 struct tty_struct *tty = tty_port_tty_get(port);
305 struct line *line = tty->driver_data;
308 unregister_winch(tty);
313 static const struct tty_port_operations line_port_ops = {
314 .activate = line_activate,
315 .destruct = line_destruct,
318 int line_open(struct tty_struct *tty, struct file *filp)
320 struct line *line = tty->driver_data;
322 return tty_port_open(&line->port, tty, filp);
325 int line_install(struct tty_driver *driver, struct tty_struct *tty,
330 ret = tty_standard_install(driver, tty);
334 tty->driver_data = line;
339 void line_close(struct tty_struct *tty, struct file * filp)
341 struct line *line = tty->driver_data;
343 tty_port_close(&line->port, tty, filp);
346 void line_hangup(struct tty_struct *tty)
348 struct line *line = tty->driver_data;
350 tty_port_hangup(&line->port);
353 void close_lines(struct line *lines, int nlines)
357 for(i = 0; i < nlines; i++)
358 close_chan(&lines[i]);
361 int setup_one_line(struct line *lines, int n, char *init,
362 const struct chan_opts *opts, char **error_out)
364 struct line *line = &lines[n];
365 struct tty_driver *driver = line->driver->driver;
368 if (line->port.count) {
369 *error_out = "Device is already open";
373 if (!strcmp(init, "none")) {
376 kfree(line->init_str);
377 tty_unregister_device(driver, n);
378 parse_chan_pair(NULL, line, n, opts, error_out);
382 char *new = kstrdup(init, GFP_KERNEL);
384 *error_out = "Failed to allocate memory";
388 tty_unregister_device(driver, n);
389 kfree(line->init_str);
391 line->init_str = new;
393 err = parse_chan_pair(new, line, n, opts, error_out);
395 struct device *d = tty_port_register_device(&line->port,
398 *error_out = "Failed to register device";
400 parse_chan_pair(NULL, line, n, opts, error_out);
404 line->init_str = NULL;
414 * Common setup code for both startup command line and mconsole initialization.
415 * @lines contains the array (of size @num) to modify;
416 * @init is the setup string;
417 * @error_out is an error string in the case of failure;
420 int line_setup(char **conf, unsigned int num, char **def,
421 char *init, char *name)
427 * We said con=/ssl= instead of con#=, so we are configuring all
433 unsigned n = simple_strtoul(init, &end, 0);
436 error = "Couldn't parse device number";
440 error = "Device number out of range";
448 printk(KERN_ERR "Failed to set up %s with "
449 "configuration string \"%s\" : %s\n", name, init, error);
453 int line_config(struct line *lines, unsigned int num, char *str,
454 const struct chan_opts *opts, char **error_out)
460 *error_out = "Can't configure all devices from mconsole";
464 n = simple_strtoul(str, &end, 0);
466 *error_out = "Couldn't parse device number";
470 *error_out = "Device number out of range";
474 return setup_one_line(lines, n, end, opts, error_out);
477 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
478 int size, char **error_out)
484 dev = simple_strtoul(name, &end, 0);
485 if ((*end != '\0') || (end == name)) {
486 *error_out = "line_get_config failed to parse device number";
490 if ((dev < 0) || (dev >= num)) {
491 *error_out = "device number out of range";
498 CONFIG_CHUNK(str, size, n, "none", 1);
500 struct tty_struct *tty = tty_port_tty_get(&line->port);
502 CONFIG_CHUNK(str, size, n, line->init_str, 1);
504 n = chan_config_string(line, str, size, error_out);
512 int line_id(char **str, int *start_out, int *end_out)
517 n = simple_strtoul(*str, &end, 0);
518 if ((*end != '\0') || (end == *str))
527 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
530 *error_out = "Device number out of range";
533 return setup_one_line(lines, n, "none", NULL, error_out);
536 int register_lines(struct line_driver *line_driver,
537 const struct tty_operations *ops,
538 struct line *lines, int nlines)
540 struct tty_driver *driver = alloc_tty_driver(nlines);
547 driver->driver_name = line_driver->name;
548 driver->name = line_driver->device_name;
549 driver->major = line_driver->major;
550 driver->minor_start = line_driver->minor_start;
551 driver->type = line_driver->type;
552 driver->subtype = line_driver->subtype;
553 driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
554 driver->init_termios = tty_std_termios;
556 for (i = 0; i < nlines; i++) {
557 tty_port_init(&lines[i].port);
558 lines[i].port.ops = &line_port_ops;
559 spin_lock_init(&lines[i].lock);
560 lines[i].driver = line_driver;
561 INIT_LIST_HEAD(&lines[i].chan_list);
563 tty_set_operations(driver, ops);
565 err = tty_register_driver(driver);
567 printk(KERN_ERR "register_lines : can't register %s driver\n",
569 put_tty_driver(driver);
570 for (i = 0; i < nlines; i++)
571 tty_port_destroy(&lines[i].port);
575 line_driver->driver = driver;
576 mconsole_register_dev(&line_driver->mc);
580 static DEFINE_SPINLOCK(winch_handler_lock);
581 static LIST_HEAD(winch_handlers);
584 struct list_head list;
588 struct tty_port *port;
590 struct work_struct work;
593 static void __free_winch(struct work_struct *work)
595 struct winch *winch = container_of(work, struct winch, work);
596 um_free_irq(WINCH_IRQ, winch);
598 if (winch->pid != -1)
599 os_kill_process(winch->pid, 1);
600 if (winch->stack != 0)
601 free_stack(winch->stack, 0);
605 static void free_winch(struct winch *winch)
611 list_del(&winch->list);
612 __free_winch(&winch->work);
615 static irqreturn_t winch_interrupt(int irq, void *data)
617 struct winch *winch = data;
618 struct tty_struct *tty;
626 err = generic_read(fd, &c, NULL);
628 if (err != -EAGAIN) {
630 list_del(&winch->list);
632 printk(KERN_ERR "winch_interrupt : "
633 "read failed, errno = %d\n", -err);
634 printk(KERN_ERR "fd %d is losing SIGWINCH "
635 "support\n", winch->tty_fd);
636 INIT_WORK(&winch->work, __free_winch);
637 schedule_work(&winch->work);
643 tty = tty_port_tty_get(winch->port);
645 line = tty->driver_data;
647 chan_window_size(line, &tty->winsize.ws_row,
648 &tty->winsize.ws_col);
649 pgrp = tty_get_pgrp(tty);
651 kill_pgrp(pgrp, SIGWINCH, 1);
660 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_port *port,
665 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
667 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
671 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
678 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
679 IRQF_SHARED, "winch", winch) < 0) {
680 printk(KERN_ERR "register_winch_irq - failed to register "
685 spin_lock(&winch_handler_lock);
686 list_add(&winch->list, &winch_handlers);
687 spin_unlock(&winch_handler_lock);
694 os_kill_process(pid, 1);
697 free_stack(stack, 0);
700 static void unregister_winch(struct tty_struct *tty)
702 struct list_head *ele, *next;
704 struct tty_struct *wtty;
706 spin_lock(&winch_handler_lock);
708 list_for_each_safe(ele, next, &winch_handlers) {
709 winch = list_entry(ele, struct winch, list);
710 wtty = tty_port_tty_get(winch->port);
717 spin_unlock(&winch_handler_lock);
720 static void winch_cleanup(void)
722 struct list_head *ele, *next;
725 spin_lock(&winch_handler_lock);
727 list_for_each_safe(ele, next, &winch_handlers) {
728 winch = list_entry(ele, struct winch, list);
732 spin_unlock(&winch_handler_lock);
734 __uml_exitcall(winch_cleanup);
736 char *add_xterm_umid(char *base)
745 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
746 title = kmalloc(len, GFP_KERNEL);
748 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
752 snprintf(title, len, "%s (%s)", base, umid);