line.c

来自「LINUX 2.6.17.4的源码」· C语言 代码 · 共 842 行 · 第 1/2 页

	line->have_irq = 1;
	return err;
}

int line_open(struct line *lines, struct tty_struct *tty)
{
	struct line *line;
	int err = -ENODEV;

	line = &lines[tty->index];
	tty->driver_data = line;

	/* The IRQ which takes this lock is not yet enabled and won't be run
	 * before the end, so we don't need to use spin_lock_irq.*/
	spin_lock(&line->lock);

	tty->driver_data = line;
	line->tty = tty;
	if(!line->valid)
		goto out;

	if(tty->count == 1){
		/* Here the device is opened, if necessary, and interrupt
		 * is registered.
		 */
		enable_chan(line);
		INIT_WORK(&line->task, line_timer_cb, line);

		if(!line->sigio){
			chan_enable_winch(&line->chan_list, tty);
			line->sigio = 1;
		}

		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
				 &tty->winsize.ws_col);
	}

	err = 0;
out:
	spin_unlock(&line->lock);
	return err;
}

static void unregister_winch(struct tty_struct *tty);

void line_close(struct tty_struct *tty, struct file * filp)
{
	struct line *line = tty->driver_data;

	/* XXX: I assume this should be called in process context, not with
         *  interrupts disabled!
         */
	spin_lock_irq(&line->lock);

	/* We ignore the error anyway! */
	flush_buffer(line);

	if(tty->count == 1){
		line->tty = NULL;
		tty->driver_data = NULL;

		if(line->sigio){
			unregister_winch(tty);
			line->sigio = 0;
		}
        }

	spin_unlock_irq(&line->lock);
}

void close_lines(struct line *lines, int nlines)
{
	int i;

	for(i = 0; i < nlines; i++)
		close_chan(&lines[i].chan_list, 0);
}

/* Common setup code for both startup command line and mconsole initialization.
 * @lines contains the the array (of size @num) to modify;
 * @init is the setup string;
 */

int line_setup(struct line *lines, unsigned int num, char *init)
{
	int i, n;
	char *end;

	if(*init == '=') {
		/* We said con=/ssl= instead of con#=, so we are configuring all
		 * consoles at once.*/
		n = -1;
	}
	else {
		n = simple_strtoul(init, &end, 0);
		if(*end != '='){
			printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
			       init);
			return 0;
		}
		init = end;
	}
	init++;

	if (n >= (signed int) num) {
		printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
		       n, num - 1);
		return 0;
	}
	else if (n >= 0){
		if (lines[n].tty != NULL) {
			printk("line_setup - device %d is open\n", n);
			return 0;
		}
		if (lines[n].init_pri <= INIT_ONE){
			lines[n].init_pri = INIT_ONE;
			if (!strcmp(init, "none"))
				lines[n].valid = 0;
			else {
				lines[n].init_str = init;
				lines[n].valid = 1;
			}
		}
	}
	else {
		for(i = 0; i < num; i++){
			if(lines[i].init_pri <= INIT_ALL){
				lines[i].init_pri = INIT_ALL;
				if(!strcmp(init, "none")) lines[i].valid = 0;
				else {
					lines[i].init_str = init;
					lines[i].valid = 1;
				}
			}
		}
	}
	return n == -1 ? num : n;
}

int line_config(struct line *lines, unsigned int num, char *str,
		struct chan_opts *opts)
{
	struct line *line;
	char *new;
	int n;

	if(*str == '='){
		printk("line_config - can't configure all devices from "
		       "mconsole\n");
		return 1;
	}

	new = kstrdup(str, GFP_KERNEL);
	if(new == NULL){
		printk("line_config - kstrdup failed\n");
		return 1;
	}
	n = line_setup(lines, num, new);
	if(n < 0)
		return 1;

	line = &lines[n];
	return parse_chan_pair(line->init_str, line, n, opts);
}

int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
		    int size, char **error_out)
{
	struct line *line;
	char *end;
	int dev, n = 0;

	dev = simple_strtoul(name, &end, 0);
	if((*end != '\0') || (end == name)){
		*error_out = "line_get_config failed to parse device number";
		return 0;
	}

	if((dev < 0) || (dev >= num)){
		*error_out = "device number out of range";
		return 0;
	}

	line = &lines[dev];

	spin_lock(&line->lock);
	if(!line->valid)
		CONFIG_CHUNK(str, size, n, "none", 1);
	else if(line->tty == NULL)
		CONFIG_CHUNK(str, size, n, line->init_str, 1);
	else n = chan_config_string(&line->chan_list, str, size, error_out);
	spin_unlock(&line->lock);

	return n;
}

int line_id(char **str, int *start_out, int *end_out)
{
	char *end;
        int n;

	n = simple_strtoul(*str, &end, 0);
	if((*end != '\0') || (end == *str))
                return -1;

        *str = end;
        *start_out = n;
        *end_out = n;
        return n;
}

int line_remove(struct line *lines, unsigned int num, int n)
{
	int err;
	char config[sizeof("conxxxx=none\0")];

	sprintf(config, "%d=none", n);
	err = line_setup(lines, num, config);
	if(err >= 0)
		err = 0;
	return err;
}

struct tty_driver *line_register_devfs(struct lines *set,
			 struct line_driver *line_driver,
			 struct tty_operations *ops, struct line *lines,
			 int nlines)
{
	int i;
	struct tty_driver *driver = alloc_tty_driver(nlines);

	if (!driver)
		return NULL;

	driver->driver_name = line_driver->name;
	driver->name = line_driver->device_name;
	driver->devfs_name = line_driver->devfs_name;
	driver->major = line_driver->major;
	driver->minor_start = line_driver->minor_start;
	driver->type = line_driver->type;
	driver->subtype = line_driver->subtype;
	driver->flags = TTY_DRIVER_REAL_RAW;
	driver->init_termios = tty_std_termios;
	tty_set_operations(driver, ops);

	if (tty_register_driver(driver)) {
		printk("%s: can't register %s driver\n",
		       __FUNCTION__,line_driver->name);
		put_tty_driver(driver);
		return NULL;
	}

	for(i = 0; i < nlines; i++){
		if(!lines[i].valid)
			tty_unregister_device(driver, i);
	}

	mconsole_register_dev(&line_driver->mc);
	return driver;
}

static DEFINE_SPINLOCK(winch_handler_lock);
static LIST_HEAD(winch_handlers);

void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
{
	struct line *line;
	int i;

	for(i = 0; i < nlines; i++){
		line = &lines[i];
		INIT_LIST_HEAD(&line->chan_list);

		if(line->init_str == NULL)
			continue;

		line->init_str = kstrdup(line->init_str, GFP_KERNEL);
		if(line->init_str == NULL)
			printk("lines_init - kstrdup returned NULL\n");

		if(parse_chan_pair(line->init_str, line, i, opts)){
			printk("parse_chan_pair failed for device %d\n", i);
			line->valid = 0;
		}
	}
}

struct winch {
	struct list_head list;
	int fd;
	int tty_fd;
	int pid;
	struct tty_struct *tty;
};

static irqreturn_t winch_interrupt(int irq, void *data, struct pt_regs *unused)
{
	struct winch *winch = data;
	struct tty_struct *tty;
	struct line *line;
	int err;
	char c;

	if(winch->fd != -1){
		err = generic_read(winch->fd, &c, NULL);
		if(err < 0){
			if(err != -EAGAIN){
				printk("winch_interrupt : read failed, "
				       "errno = %d\n", -err);
				printk("fd %d is losing SIGWINCH support\n",
				       winch->tty_fd);
				return IRQ_HANDLED;
			}
			goto out;
		}
	}
	tty  = winch->tty;
	if (tty != NULL) {
		line = tty->driver_data;
		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
				 &tty->winsize.ws_col);
		kill_pg(tty->pgrp, SIGWINCH, 1);
	}
 out:
	if(winch->fd != -1)
		reactivate_fd(winch->fd, WINCH_IRQ);
	return IRQ_HANDLED;
}

void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty)
{
	struct winch *winch;

	winch = kmalloc(sizeof(*winch), GFP_KERNEL);
	if (winch == NULL) {
		printk("register_winch_irq - kmalloc failed\n");
		return;
	}

	*winch = ((struct winch) { .list  	= LIST_HEAD_INIT(winch->list),
				   .fd  	= fd,
				   .tty_fd 	= tty_fd,
				   .pid  	= pid,
				   .tty 	= tty });

	spin_lock(&winch_handler_lock);
	list_add(&winch->list, &winch_handlers);
	spin_unlock(&winch_handler_lock);

	if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
			  SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
			  "winch", winch) < 0)
		printk("register_winch_irq - failed to register IRQ\n");
}

static void free_winch(struct winch *winch)
{
	list_del(&winch->list);

	if(winch->pid != -1)
		os_kill_process(winch->pid, 1);
	if(winch->fd != -1)
		os_close_file(winch->fd);

	free_irq(WINCH_IRQ, winch);
	kfree(winch);
}

static void unregister_winch(struct tty_struct *tty)
{
	struct list_head *ele;
	struct winch *winch;

	spin_lock(&winch_handler_lock);

	list_for_each(ele, &winch_handlers){
		winch = list_entry(ele, struct winch, list);
                if(winch->tty == tty){
			free_winch(winch);
			break;
                }
        }
	spin_unlock(&winch_handler_lock);
}

static void winch_cleanup(void)
{
	struct list_head *ele, *next;
	struct winch *winch;

	spin_lock(&winch_handler_lock);

	list_for_each_safe(ele, next, &winch_handlers){
		winch = list_entry(ele, struct winch, list);
		free_winch(winch);
	}

	spin_unlock(&winch_handler_lock);
}
__uml_exitcall(winch_cleanup);

char *add_xterm_umid(char *base)
{
	char *umid, *title;
	int len;

	umid = get_umid();
	if(*umid == '\0')
		return base;

	len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
	title = kmalloc(len, GFP_KERNEL);
	if(title == NULL){
		printk("Failed to allocate buffer for xterm title\n");
		return base;
	}

	snprintf(title, len, "%s (%s)", base, umid);
	return title;
}