um/drivers/line.c

22 	struct line *line = chan->line;
24 	if (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 unsigned int write_room(struct line *line)
39 	if (line->buffer == NULL)
43 	n = line->head - line->tail;
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);
65 	struct line *line = tty->driver_data;
69 	spin_lock_irqsave(&line->lock, flags);
71 	ret = LINE_BUFSIZE - (write_room(line) + 1);
72 	spin_unlock_irqrestore(&line->lock, flags);
79  * this line.
84  * Must be called while holding line->lock!
86 static int buffer_data(struct line *line, const u8 *buf, size_t len)
90 	if (line->buffer == NULL) {
91 		line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
92 		if (line->buffer == NULL) {
97 		line->head = line->buffer;
98 		line->tail = line->buffer;
101 	room = write_room(line);
104 	end = line->buffer + LINE_BUFSIZE - line->tail;
107 		memcpy(line->tail, buf, len);
108 		line->tail += len;
112 		memcpy(line->tail, buf, end);
114 		memcpy(line->buffer, buf, len - end);
115 		line->tail = line->buffer + len - end;
123  * called, passing it line->head as buffer, and an appropriate count.
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->write_irq);
150 			line->head = line->buffer;
152 			line->head += n;
157 	count = line->tail - line->head;
158 	n = write_chan(line->chan_out, line->head, count,
159 		       line->write_irq);
164 	line->head += n;
165 	return line->head == line->tail;
170 	struct line *line = tty->driver_data;
173 	spin_lock_irqsave(&line->lock, flags);
174 	flush_buffer(line);
175 	spin_unlock_irqrestore(&line->lock, flags);
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->write_irq);
207 			ret += buffer_data(line, buf + n, len);
210 	spin_unlock_irqrestore(&line->lock, flags);
216 	struct line *line = tty->driver_data;
218 	deactivate_chan(line->chan_in, line->read_irq);
219 	line->throttled = 1;
224 	struct line *line = tty->driver_data;
226 	line->throttled = 0;
227 	chan_interrupt(line, line->read_irq);
233 	struct line *line = chan->line;
241 	spin_lock(&line->lock);
242 	err = flush_buffer(line);
244 		spin_unlock(&line->lock);
247 		line->head = line->buffer;
248 		line->tail = line->buffer;
250 	spin_unlock(&line->lock);
252 	tty_port_tty_wakeup(&line->port);
257 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
259 	const struct line_driver *driver = line->driver;
269 		line->read_irq = err;
279 		line->write_irq = err;
288 	struct line *line = tty->driver_data;
290 	ret = enable_chan(line);
294 	if (!line->sigio) {
295 		chan_enable_winch(line->chan_out, port);
296 		line->sigio = 1;
299 	chan_window_size(line, &tty->winsize.ws_row,
310 	struct line *line = tty->driver_data;
312 	if (line->sigio) {
314 		line->sigio = 0;
325 	struct line *line = tty->driver_data;
327 	return tty_port_open(&line->port, tty, filp);
331 		 struct line *line)
339 	tty->driver_data = line;
346 	struct line *line = tty->driver_data;
348 	tty_port_close(&line->port, tty, filp);
353 	struct line *line = tty->driver_data;
355 	tty_port_hangup(&line->port);
358 void close_lines(struct line *lines, int nlines)
366 int setup_one_line(struct line *lines, int n, char *init,
369 	struct line *line = &lines[n];
370 	struct tty_driver *driver = line->driver->driver;
373 	if (line->port.count) {
379 		if (line->valid) {
380 			line->valid = 0;
381 			kfree(line->init_str);
383 			parse_chan_pair(NULL, line, n, opts, error_out);
393 		if (line->valid) {
395 			kfree(line->init_str);
397 		line->init_str = new;
398 		line->valid = 1;
399 		err = parse_chan_pair(new, line, n, opts, error_out);
401 			struct device *d = tty_port_register_device(&line->port,
406 				parse_chan_pair(NULL, line, n, opts, error_out);
411 			line->init_str = NULL;
412 			line->valid = 0;
421  * Common setup code for both startup command line and mconsole initialization.
460 int line_config(struct line *lines, unsigned int num, char *str,
484 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
487 	struct line *line;
502 	line = &lines[dev];
504 	if (!line->valid)
507 		struct tty_struct *tty = tty_port_tty_get(&line->port);
509 			CONFIG_CHUNK(str, size, n, line->init_str, 1);
511 			n = chan_config_string(line, str, size, error_out);
534 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
545 		   struct line *lines, int nlines)
626 	struct line *line;
655 		line = tty->driver_data;
656 		if (line != NULL) {
657 			chan_window_size(line, &tty->winsize.ws_row,