1 // SPDX-License-Identifier: GPL-2.0+
12 #include <linux/console.h>
46  * native transfer size. We could make them selectable in the
61 static atomic_t hvc_needs_init __read_mostly = ATOMIC_INIT(-1);
79  * This value is used to assign a tty->index value to a hvc_struct based
81  * a console candidate registered with hvc_instantiate().
83 static int last_hvc = -1;
98 		spin_lock_irqsave(&hp->lock, flags);  in hvc_get_by_index()
99 		if (hp->index == index) {  in hvc_get_by_index()
100 			tty_port_get(&hp->port);  in hvc_get_by_index()
101 			spin_unlock_irqrestore(&hp->lock, flags);  in hvc_get_by_index()
105 		spin_unlock_irqrestore(&hp->lock, flags);  in hvc_get_by_index()
118 	if (ops->flush)  in __hvc_flush()
119 		return ops->flush(vtermno, wait);  in __hvc_flush()
129  * Wait for the console to flush before writing more to it. This sleeps.
133 	return __hvc_flush(hp->ops, hp->vtermno, true);  in hvc_flush()
137  * Initial console vtermnos for console API usage prior to full console
139  * console interfaces but can still be used as a tty device.  This has to be
140  * static because kmalloc will not work during early console init.
144 	{[0 ... MAX_NR_HVC_CONSOLES - 1] = -1};
147  * Console APIs, NOT TTY.  These APIs are available immediately when
151 static void hvc_console_print(struct console *co, const char *b,  in hvc_console_print()
156 	int r, donecr = 0, index = co->index;  in hvc_console_print()
158 	/* Console access attempt outside of acceptable console range. */  in hvc_console_print()
162 	/* This console adapter was removed so it is not usable. */  in hvc_console_print()
163 	if (vtermnos[index] == -1)  in hvc_console_print()
174 				--count;  in hvc_console_print()
177 			r = cons_ops[index]->put_chars(vtermnos[index], c, i);  in hvc_console_print()
180 				 * but spin in case of -EAGAIN */  in hvc_console_print()
181 				if (r != -EAGAIN) {  in hvc_console_print()
188 				i -= r;  in hvc_console_print()
197 static struct tty_driver *hvc_console_device(struct console *c, int *index)  in hvc_console_device()
199 	if (vtermnos[c->index] == -1)  in hvc_console_device()
202 	*index = c->index;  in hvc_console_device()
206 static int hvc_console_setup(struct console *co, char *options)  in hvc_console_setup()
208 	if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES)  in hvc_console_setup()
209 		return -ENODEV;  in hvc_console_setup()
211 	if (vtermnos[co->index] == -1)  in hvc_console_setup()
212 		return -ENODEV;  in hvc_console_setup()
217 static struct console hvc_console = {
223 	.index		= -1,
227  * Early console initialization.  Precedes driver initialization.
230  * -- index will remain -1
232  * -- index will be set to 0, then we will fail setup.
234  * -- index will be set to user specified driver, and we will fail
236  * -- if the user didn't specify a driver then the console will match
256 	spin_lock_irqsave(&hp->lock, flags);  in hvc_port_destruct()
257 	list_del(&(hp->next));  in hvc_port_destruct()
258 	spin_unlock_irqrestore(&hp->lock, flags);  in hvc_port_destruct()
280  * hvc_instantiate() is an early console discovery method which locates
283  * appear after early console init.
290 		return -1;  in hvc_instantiate()
292 	if (vtermnos[index] != -1)  in hvc_instantiate()
293 		return -1;  in hvc_instantiate()
298 		tty_port_put(&hp->port);  in hvc_instantiate()
299 		return -1;  in hvc_instantiate()
305 	/* check if we need to re-register the kernel console */  in hvc_instantiate()
331 	hp = hvc_get_by_index(tty->index);  in hvc_install()
333 		return -ENODEV;  in hvc_install()
335 	tty->driver_data = hp;  in hvc_install()
337 	rc = tty_port_install(&hp->port, driver, tty);  in hvc_install()
339 		tty_port_put(&hp->port);  in hvc_install()
349 	struct hvc_struct *hp = tty->driver_data;  in hvc_open()
353 	spin_lock_irqsave(&hp->port.lock, flags);  in hvc_open()
355 	if (hp->port.count++ > 0) {  in hvc_open()
356 		spin_unlock_irqrestore(&hp->port.lock, flags);  in hvc_open()
360 	spin_unlock_irqrestore(&hp->port.lock, flags);  in hvc_open()
362 	tty_port_tty_set(&hp->port, tty);  in hvc_open()
364 	if (hp->ops->notifier_add)  in hvc_open()
365 		rc = hp->ops->notifier_add(hp, hp->data);  in hvc_open()
378 			if (hp->ops->dtr_rts)  in hvc_open()
379 				hp->ops->dtr_rts(hp, 1);  in hvc_open()
380 		tty_port_set_initialized(&hp->port, true);  in hvc_open()
391 	struct hvc_struct *hp = tty->driver_data;  in hvc_close()
397 	spin_lock_irqsave(&hp->port.lock, flags);  in hvc_close()
399 	if (--hp->port.count == 0) {  in hvc_close()
400 		spin_unlock_irqrestore(&hp->port.lock, flags);  in hvc_close()
402 		tty_port_tty_set(&hp->port, NULL);  in hvc_close()
404 		if (!tty_port_initialized(&hp->port))  in hvc_close()
408 			if (hp->ops->dtr_rts)  in hvc_close()
409 				hp->ops->dtr_rts(hp, 0);  in hvc_close()
411 		if (hp->ops->notifier_del)  in hvc_close()
412 			hp->ops->notifier_del(hp, hp->data);  in hvc_close()
415 		cancel_work_sync(&hp->tty_resize);  in hvc_close()
423 		tty_port_set_initialized(&hp->port, false);  in hvc_close()
425 		if (hp->port.count < 0)  in hvc_close()
427 				hp->vtermno, hp->port.count);  in hvc_close()
428 		spin_unlock_irqrestore(&hp->port.lock, flags);  in hvc_close()
434 	struct hvc_struct *hp = tty->driver_data;  in hvc_cleanup()
436 	tty_port_put(&hp->port);  in hvc_cleanup()
441 	struct hvc_struct *hp = tty->driver_data;  in hvc_hangup()
448 	cancel_work_sync(&hp->tty_resize);  in hvc_hangup()
450 	spin_lock_irqsave(&hp->port.lock, flags);  in hvc_hangup()
454 	 * open->hangup case this can be called after the final close so prevent  in hvc_hangup()
457 	if (hp->port.count <= 0) {  in hvc_hangup()
458 		spin_unlock_irqrestore(&hp->port.lock, flags);  in hvc_hangup()
462 	hp->port.count = 0;  in hvc_hangup()
463 	spin_unlock_irqrestore(&hp->port.lock, flags);  in hvc_hangup()
464 	tty_port_tty_set(&hp->port, NULL);  in hvc_hangup()
466 	hp->n_outbuf = 0;  in hvc_hangup()
468 	if (hp->ops->notifier_hangup)  in hvc_hangup()
469 		hp->ops->notifier_hangup(hp, hp->data);  in hvc_hangup()
474  * on a blocked hypervisor.  Call this function with hp->lock held.
480 	n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);  in hvc_push()
482 		if (n == 0 || n == -EAGAIN) {  in hvc_push()
483 			hp->do_wakeup = 1;  in hvc_push()
488 		hp->n_outbuf = 0;  in hvc_push()
490 		hp->n_outbuf -= n;  in hvc_push()
491 	if (hp->n_outbuf > 0)  in hvc_push()
492 		memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf);  in hvc_push()
494 		hp->do_wakeup = 1;  in hvc_push()
501 	struct hvc_struct *hp = tty->driver_data;  in hvc_write()
507 		return -EPIPE;  in hvc_write()
510 	if (hp->port.count <= 0)  in hvc_write()
511 		return -EIO;  in hvc_write()
516 		spin_lock_irqsave(&hp->lock, flags);  in hvc_write()
518 		rsize = hp->outbuf_size - hp->n_outbuf;  in hvc_write()
523 			memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);  in hvc_write()
524 			count -= rsize;  in hvc_write()
526 			hp->n_outbuf += rsize;  in hvc_write()
530 		if (hp->n_outbuf > 0)  in hvc_write()
533 		spin_unlock_irqrestore(&hp->lock, flags);  in hvc_write()
539 			if (hp->n_outbuf > 0)  in hvc_write()
548 	if (hp->n_outbuf)  in hvc_write()
555  * hvc_set_winsz() - Resize the hvc tty terminal window.
561  * Locking:	hp->lock
572 	tty = tty_port_tty_get(&hp->port);  in hvc_set_winsz()
576 	spin_lock_irqsave(&hp->lock, hvc_flags);  in hvc_set_winsz()
577 	ws = hp->ws;  in hvc_set_winsz()
578 	spin_unlock_irqrestore(&hp->lock, hvc_flags);  in hvc_set_winsz()
591 	struct hvc_struct *hp = tty->driver_data;  in hvc_write_room()
596 	return hp->outbuf_size - hp->n_outbuf;  in hvc_write_room()
601 	struct hvc_struct *hp = tty->driver_data;  in hvc_chars_in_buffer()
605 	return hp->n_outbuf;  in hvc_chars_in_buffer()
610  * and during console activity we will use a default MIN_TIMEOUT of 10.  When
611  * the console is idle, we increase the timeout value on each pass through
613  * one second) delay on the console before the console responds to input when
621  * Maximum number of bytes to get from the console driver if hvc_poll is
624  * console with the OPAL driver that results in about 0.25ms interrupts off
641 	spin_lock_irqsave(&hp->lock, flags);  in __hvc_poll()
644 	if (hp->n_outbuf > 0)  in __hvc_poll()
648 	if (hp->n_outbuf > 0) {  in __hvc_poll()
655 		spin_unlock_irqrestore(&hp->lock, flags);  in __hvc_poll()
657 		spin_lock_irqsave(&hp->lock, flags);  in __hvc_poll()
661 	tty = tty_port_tty_get(&hp->port);  in __hvc_poll()
672 	if (!hp->irq_requested)  in __hvc_poll()
677 	count = tty_buffer_request_room(&hp->port, N_INBUF);  in __hvc_poll()
685 	n = hp->ops->get_chars(hp->vtermno, buf, count);  in __hvc_poll()
688 		if (n == -EPIPE) {  in __hvc_poll()
689 			spin_unlock_irqrestore(&hp->lock, flags);  in __hvc_poll()
691 			spin_lock_irqsave(&hp->lock, flags);  in __hvc_poll()
692 		} else if ( n == -EAGAIN ) {  in __hvc_poll()
694 			 * Some back-ends can only ensure a certain min  in __hvc_poll()
705 		if (hp->index == hvc_console.index) {  in __hvc_poll()
721 		tty_insert_flip_char(&hp->port, buf[i], 0);  in __hvc_poll()
727 		spin_unlock_irqrestore(&hp->lock, flags);  in __hvc_poll()
729 		spin_lock_irqsave(&hp->lock, flags);  in __hvc_poll()
743 	if (hp->do_wakeup) {  in __hvc_poll()
744 		hp->do_wakeup = 0;  in __hvc_poll()
748 	spin_unlock_irqrestore(&hp->lock, flags);  in __hvc_poll()
755 		tty_flip_buffer_push(&hp->port);  in __hvc_poll()
769  * __hvc_resize() - Update terminal window size information.
770  * @hp:		HVC console pointer
771  * @ws:		Terminal window size structure
773  * Stores the specified window size information in the hvc structure of @hp.
776  * Locking:	Locking free; the function MUST be called holding hp->lock
780 	hp->ws = ws;  in __hvc_resize()
781 	schedule_work(&hp->tty_resize);  in __hvc_resize()
787  * calling hvc_poll() who determines whether a console adapter support
838 	struct hvc_struct *hp = tty->driver_data;  in hvc_tiocmget()
840 	if (!hp || !hp->ops->tiocmget)  in hvc_tiocmget()
841 		return -EINVAL;  in hvc_tiocmget()
842 	return hp->ops->tiocmget(hp);  in hvc_tiocmget()
848 	struct hvc_struct *hp = tty->driver_data;  in hvc_tiocmset()
850 	if (!hp || !hp->ops->tiocmset)  in hvc_tiocmset()
851 		return -EINVAL;  in hvc_tiocmset()
852 	return hp->ops->tiocmset(hp, set, clear);  in hvc_tiocmset()
863 	struct tty_struct *tty = driver->ttys[0];  in hvc_poll_get_char()
864 	struct hvc_struct *hp = tty->driver_data;  in hvc_poll_get_char()
868 	n = hp->ops->get_chars(hp->vtermno, &ch, 1);  in hvc_poll_get_char()
878 	struct tty_struct *tty = driver->ttys[0];  in hvc_poll_put_char()
879 	struct hvc_struct *hp = tty->driver_data;  in hvc_poll_put_char()
883 		n = hp->ops->put_chars(hp->vtermno, &ch, 1);  in hvc_poll_put_char()
928 		return ERR_PTR(-ENOMEM);  in hvc_alloc()
930 	hp->vtermno = vtermno;  in hvc_alloc()
931 	hp->data = data;  in hvc_alloc()
932 	hp->ops = ops;  in hvc_alloc()
933 	hp->outbuf_size = outbuf_size;  in hvc_alloc()
934 	hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))];  in hvc_alloc()
936 	tty_port_init(&hp->port);  in hvc_alloc()
937 	hp->port.ops = &hvc_port_ops;  in hvc_alloc()
939 	INIT_WORK(&hp->tty_resize, hvc_set_winsz);  in hvc_alloc()
940 	spin_lock_init(&hp->lock);  in hvc_alloc()
945 	 * see if this vterm id matches one registered for console.  in hvc_alloc()
948 		if (vtermnos[i] == hp->vtermno &&  in hvc_alloc()
949 		    cons_ops[i] == hp->ops)  in hvc_alloc()
954 		/* find 'empty' slot for console */  in hvc_alloc()
955 		for (i = 0; i < MAX_NR_HVC_CONSOLES && vtermnos[i] != -1; i++) {  in hvc_alloc()
963 	hp->index = i;  in hvc_alloc()
969 	list_add_tail(&(hp->next), &hvc_structs);  in hvc_alloc()
972 	/* check if we need to re-register the kernel console */  in hvc_alloc()
984 	tty = tty_port_tty_get(&hp->port);  in hvc_remove()
987 	spin_lock_irqsave(&hp->lock, flags);  in hvc_remove()
988 	if (hp->index < MAX_NR_HVC_CONSOLES) {  in hvc_remove()
989 		vtermnos[hp->index] = -1;  in hvc_remove()
990 		cons_ops[hp->index] = NULL;  in hvc_remove()
993 	/* Don't whack hp->irq because tty_hangup() will need to free the irq. */  in hvc_remove()
995 	spin_unlock_irqrestore(&hp->lock, flags);  in hvc_remove()
1004 	tty_port_put(&hp->port);  in hvc_remove()
1031 	drv->driver_name = "hvc";  in hvc_init()
1032 	drv->name = "hvc";  in hvc_init()
1033 	drv->major = HVC_MAJOR;  in hvc_init()
1034 	drv->minor_start = HVC_MINOR;  in hvc_init()
1035 	drv->type = TTY_DRIVER_TYPE_SYSTEM;  in hvc_init()
1036 	drv->init_termios = tty_std_termios;  in hvc_init()
1043 		printk(KERN_ERR "Couldn't create kthread for console.\n");  in hvc_init()
1050 		printk(KERN_ERR "Couldn't register hvc console driver\n");  in hvc_init()