Commit 70b5c4ee authored by Michael Ellerman's avatar Michael Ellerman
Browse files

Merge branch 'topic/hvc' into next 

This branch held some hvc related commits (Hypervisor Virtual Console)
so that they could get some wider testing in linux-next before merging.
parents b3124ec2 9f65b81f

drivers/tty/hvc/hvc_console.c

+122 −72
Original line number Diff line number Diff line
@@ -73,7 +73,7 @@ static LIST_HEAD(hvc_structs); 
 * Protect the list of hvc_struct instances from inserts and removals during

 * list traversal.

 */

static DEFINE_SPINLOCK(hvc_structs_lock);

static DEFINE_MUTEX(hvc_structs_mutex);



/*

 * This value is used to assign a tty->index value to a hvc_struct based
@@ -83,7 +83,7 @@ static DEFINE_SPINLOCK(hvc_structs_lock); 
static int last_hvc = -1;



/*

 * Do not call this function with either the hvc_structs_lock or the hvc_struct

 * Do not call this function with either the hvc_structs_mutex or the hvc_struct

 * lock held.  If successful, this function increments the kref reference

 * count against the target hvc_struct so it should be released when finished.

 */
@@ -92,24 +92,46 @@ static struct hvc_struct *hvc_get_by_index(int index) 
	struct hvc_struct *hp;

	unsigned long flags;



	spin_lock(&hvc_structs_lock);

	mutex_lock(&hvc_structs_mutex);



	list_for_each_entry(hp, &hvc_structs, next) {

		spin_lock_irqsave(&hp->lock, flags);

		if (hp->index == index) {

			tty_port_get(&hp->port);

			spin_unlock_irqrestore(&hp->lock, flags);

			spin_unlock(&hvc_structs_lock);

			mutex_unlock(&hvc_structs_mutex);

			return hp;

		}

		spin_unlock_irqrestore(&hp->lock, flags);

	}

	hp = NULL;

	mutex_unlock(&hvc_structs_mutex);



	spin_unlock(&hvc_structs_lock);

	return hp;

}



static int __hvc_flush(const struct hv_ops *ops, uint32_t vtermno, bool wait)

{

	if (wait)

		might_sleep();



	if (ops->flush)

		return ops->flush(vtermno, wait);

	return 0;

}



static int hvc_console_flush(const struct hv_ops *ops, uint32_t vtermno)

{

	return __hvc_flush(ops, vtermno, false);

}



/*

 * Wait for the console to flush before writing more to it. This sleeps.

 */

static int hvc_flush(struct hvc_struct *hp)

{

	return __hvc_flush(hp->ops, hp->vtermno, true);

}



/*

 * Initial console vtermnos for console API usage prior to full console
@@ -156,8 +178,12 @@ static void hvc_console_print(struct console *co, const char *b, 
			if (r <= 0) {

				/* throw away characters on error

				 * but spin in case of -EAGAIN */

				if (r != -EAGAIN)

				if (r != -EAGAIN) {

					i = 0;

				} else {

					hvc_console_flush(cons_ops[index],

						      vtermnos[index]);

				}

			} else if (r > 0) {

				i -= r;

				if (i > 0)
@@ -165,6 +191,7 @@ static void hvc_console_print(struct console *co, const char *b, 
			}

		}

	}

	hvc_console_flush(cons_ops[index], vtermnos[index]);

}



static struct tty_driver *hvc_console_device(struct console *c, int *index)
@@ -224,13 +251,13 @@ static void hvc_port_destruct(struct tty_port *port) 
	struct hvc_struct *hp = container_of(port, struct hvc_struct, port);

	unsigned long flags;



	spin_lock(&hvc_structs_lock);

	mutex_lock(&hvc_structs_mutex);



	spin_lock_irqsave(&hp->lock, flags);

	list_del(&(hp->next));

	spin_unlock_irqrestore(&hp->lock, flags);



	spin_unlock(&hvc_structs_lock);

	mutex_unlock(&hvc_structs_mutex);



	kfree(hp);

}
@@ -494,13 +521,12 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count 
	if (hp->port.count <= 0)

		return -EIO;



	while (count > 0) {

		spin_lock_irqsave(&hp->lock, flags);



	/* Push pending writes */

	if (hp->n_outbuf > 0)

		hvc_push(hp);

		rsize = hp->outbuf_size - hp->n_outbuf;



	while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) {

		if (rsize) {

			if (rsize > count)

				rsize = count;

			memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
@@ -508,10 +534,20 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count 
			buf += rsize;

			hp->n_outbuf += rsize;

			written += rsize;

		hvc_push(hp);

		}



		if (hp->n_outbuf > 0)

			hvc_push(hp);



		spin_unlock_irqrestore(&hp->lock, flags);



		if (count) {

			if (hp->n_outbuf > 0)

				hvc_flush(hp);

			cond_resched();

		}

	}



	/*

	 * Racy, but harmless, kick thread if there is still pending data.

	 */
@@ -590,10 +626,10 @@ static u32 timeout = MIN_TIMEOUT; 
#define HVC_POLL_READ	0x00000001

#define HVC_POLL_WRITE	0x00000002



int hvc_poll(struct hvc_struct *hp)

static int __hvc_poll(struct hvc_struct *hp, bool may_sleep)

{

	struct tty_struct *tty;

	int i, n, poll_mask = 0;

	int i, n, count, poll_mask = 0;

	char buf[N_INBUF] __ALIGNED__;

	unsigned long flags;

	int read_total = 0;
@@ -612,6 +648,12 @@ int hvc_poll(struct hvc_struct *hp) 
		timeout = (written_total) ? 0 : MIN_TIMEOUT;

	}



	if (may_sleep) {

		spin_unlock_irqrestore(&hp->lock, flags);

		cond_resched();

		spin_lock_irqsave(&hp->lock, flags);

	}



	/* No tty attached, just skip */

	tty = tty_port_tty_get(&hp->port);

	if (tty == NULL)
@@ -619,7 +661,7 @@ int hvc_poll(struct hvc_struct *hp) 


	/* Now check if we can get data (are we throttled ?) */

	if (tty_throttled(tty))

		goto throttled;

		goto out;



	/* If we aren't notifier driven and aren't throttled, we always

	 * request a reschedule
@@ -628,13 +670,13 @@ int hvc_poll(struct hvc_struct *hp) 
		poll_mask |= HVC_POLL_READ;



	/* Read data if any */

	for (;;) {

		int count = tty_buffer_request_room(&hp->port, N_INBUF);



	count = tty_buffer_request_room(&hp->port, N_INBUF);



	/* If flip is full, just reschedule a later read */

	if (count == 0) {

		poll_mask |= HVC_POLL_READ;

			break;

		goto out;

	}



	n = hp->ops->get_chars(hp->vtermno, buf, count);
@@ -652,8 +694,9 @@ int hvc_poll(struct hvc_struct *hp) 
			 */

			poll_mask |= HVC_POLL_READ;

		}

			break;

		goto out;

	}



	for (i = 0; i < n; ++i) {

#ifdef CONFIG_MAGIC_SYSRQ

		if (hp->index == hvc_console.index) {
@@ -674,10 +717,11 @@ int hvc_poll(struct hvc_struct *hp) 
#endif /* CONFIG_MAGIC_SYSRQ */

		tty_insert_flip_char(&hp->port, buf[i], 0);

	}

	if (n == count)

		poll_mask |= HVC_POLL_READ;

	read_total = n;



		read_total += n;

	}

 throttled:

 out:

	/* Wakeup write queue if necessary */

	if (hp->do_wakeup) {

		hp->do_wakeup = 0;
@@ -697,6 +741,11 @@ int hvc_poll(struct hvc_struct *hp) 


	return poll_mask;

}



int hvc_poll(struct hvc_struct *hp)

{

	return __hvc_poll(hp, false);

}

EXPORT_SYMBOL_GPL(hvc_poll);



/**
@@ -733,11 +782,12 @@ static int khvcd(void *unused) 
		try_to_freeze();

		wmb();

		if (!cpus_are_in_xmon()) {

			spin_lock(&hvc_structs_lock);

			mutex_lock(&hvc_structs_mutex);

			list_for_each_entry(hp, &hvc_structs, next) {

				poll_mask |= hvc_poll(hp);

				poll_mask |= __hvc_poll(hp, true);

				cond_resched();

			}

			spin_unlock(&hvc_structs_lock);

			mutex_unlock(&hvc_structs_mutex);

		} else

			poll_mask |= HVC_POLL_READ;

		if (hvc_kicked)
@@ -871,7 +921,7 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, 


	INIT_WORK(&hp->tty_resize, hvc_set_winsz);

	spin_lock_init(&hp->lock);

	spin_lock(&hvc_structs_lock);

	mutex_lock(&hvc_structs_mutex);



	/*

	 * find index to use:
@@ -891,7 +941,7 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, 
	vtermnos[i] = vtermno;



	list_add_tail(&(hp->next), &hvc_structs);

	spin_unlock(&hvc_structs_lock);

	mutex_unlock(&hvc_structs_mutex);



	/* check if we need to re-register the kernel console */

	hvc_check_console(i);

drivers/tty/hvc/hvc_console.h

+1 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ struct hvc_struct { 
struct hv_ops {

	int (*get_chars)(uint32_t vtermno, char *buf, int count);

	int (*put_chars)(uint32_t vtermno, const char *buf, int count);

	int (*flush)(uint32_t vtermno, bool wait);



	/* Callbacks for notification. Called in open, close and hangup */

	int (*notifier_add)(struct hvc_struct *hp, int irq);