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path: root/drivers/char/tty_port.c
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Diffstat (limited to 'drivers/char/tty_port.c')
-rw-r--r--drivers/char/tty_port.c97
1 files changed, 79 insertions, 18 deletions
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index c63f3d33914a..be492dd66437 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -25,19 +25,21 @@ void tty_port_init(struct tty_port *port)
init_waitqueue_head(&port->close_wait);
init_waitqueue_head(&port->delta_msr_wait);
mutex_init(&port->mutex);
+ mutex_init(&port->buf_mutex);
spin_lock_init(&port->lock);
port->close_delay = (50 * HZ) / 100;
port->closing_wait = (3000 * HZ) / 100;
+ kref_init(&port->kref);
}
EXPORT_SYMBOL(tty_port_init);
int tty_port_alloc_xmit_buf(struct tty_port *port)
{
/* We may sleep in get_zeroed_page() */
- mutex_lock(&port->mutex);
+ mutex_lock(&port->buf_mutex);
if (port->xmit_buf == NULL)
port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
- mutex_unlock(&port->mutex);
+ mutex_unlock(&port->buf_mutex);
if (port->xmit_buf == NULL)
return -ENOMEM;
return 0;
@@ -46,15 +48,32 @@ EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
void tty_port_free_xmit_buf(struct tty_port *port)
{
- mutex_lock(&port->mutex);
+ mutex_lock(&port->buf_mutex);
if (port->xmit_buf != NULL) {
free_page((unsigned long)port->xmit_buf);
port->xmit_buf = NULL;
}
- mutex_unlock(&port->mutex);
+ mutex_unlock(&port->buf_mutex);
}
EXPORT_SYMBOL(tty_port_free_xmit_buf);
+static void tty_port_destructor(struct kref *kref)
+{
+ struct tty_port *port = container_of(kref, struct tty_port, kref);
+ if (port->xmit_buf)
+ free_page((unsigned long)port->xmit_buf);
+ if (port->ops->destruct)
+ port->ops->destruct(port);
+ else
+ kfree(port);
+}
+
+void tty_port_put(struct tty_port *port)
+{
+ if (port)
+ kref_put(&port->kref, tty_port_destructor);
+}
+EXPORT_SYMBOL(tty_port_put);
/**
* tty_port_tty_get - get a tty reference
@@ -99,10 +118,11 @@ EXPORT_SYMBOL(tty_port_tty_set);
static void tty_port_shutdown(struct tty_port *port)
{
+ mutex_lock(&port->mutex);
if (port->ops->shutdown &&
test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags))
port->ops->shutdown(port);
-
+ mutex_unlock(&port->mutex);
}
/**
@@ -120,8 +140,10 @@ void tty_port_hangup(struct tty_port *port)
spin_lock_irqsave(&port->lock, flags);
port->count = 0;
port->flags &= ~ASYNC_NORMAL_ACTIVE;
- if (port->tty)
+ if (port->tty) {
+ set_bit(TTY_IO_ERROR, &port->tty->flags);
tty_kref_put(port->tty);
+ }
port->tty = NULL;
spin_unlock_irqrestore(&port->lock, flags);
wake_up_interruptible(&port->open_wait);
@@ -198,7 +220,7 @@ EXPORT_SYMBOL(tty_port_lower_dtr_rts);
* management of these lines. Note that the dtr/rts raise is done each
* iteration as a hangup may have previously dropped them while we wait.
*/
-
+
int tty_port_block_til_ready(struct tty_port *port,
struct tty_struct *tty, struct file *filp)
{
@@ -253,7 +275,8 @@ int tty_port_block_til_ready(struct tty_port *port,
tty_port_raise_dtr_rts(port);
prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
- /* Check for a hangup or uninitialised port. Return accordingly */
+ /* Check for a hangup or uninitialised port.
+ Return accordingly */
if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {
if (port->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
@@ -285,11 +308,11 @@ int tty_port_block_til_ready(struct tty_port *port,
port->flags |= ASYNC_NORMAL_ACTIVE;
spin_unlock_irqrestore(&port->lock, flags);
return retval;
-
}
EXPORT_SYMBOL(tty_port_block_til_ready);
-int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct file *filp)
+int tty_port_close_start(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp)
{
unsigned long flags;
@@ -299,7 +322,7 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f
return 0;
}
- if( tty->count == 1 && port->count != 1) {
+ if (tty->count == 1 && port->count != 1) {
printk(KERN_WARNING
"tty_port_close_start: tty->count = 1 port count = %d.\n",
port->count);
@@ -331,12 +354,20 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f
long timeout;
if (bps > 1200)
- timeout = max_t(long, (HZ * 10 * port->drain_delay) / bps,
- HZ / 10);
+ timeout = max_t(long,
+ (HZ * 10 * port->drain_delay) / bps, HZ / 10);
else
timeout = 2 * HZ;
schedule_timeout_interruptible(timeout);
}
+ /* Flush the ldisc buffering */
+ tty_ldisc_flush(tty);
+
+ /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
+ hang up the line */
+ if (tty->termios->c_cflag & HUPCL)
+ tty_port_lower_dtr_rts(port);
+
/* Don't call port->drop for the last reference. Callers will want
to drop the last active reference in ->shutdown() or the tty
shutdown path */
@@ -348,11 +379,6 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
{
unsigned long flags;
- tty_ldisc_flush(tty);
-
- if (tty->termios->c_cflag & HUPCL)
- tty_port_lower_dtr_rts(port);
-
spin_lock_irqsave(&port->lock, flags);
tty->closing = 0;
@@ -377,7 +403,42 @@ void tty_port_close(struct tty_port *port, struct tty_struct *tty,
if (tty_port_close_start(port, tty, filp) == 0)
return;
tty_port_shutdown(port);
+ set_bit(TTY_IO_ERROR, &tty->flags);
tty_port_close_end(port, tty);
tty_port_tty_set(port, NULL);
}
EXPORT_SYMBOL(tty_port_close);
+
+int tty_port_open(struct tty_port *port, struct tty_struct *tty,
+ struct file *filp)
+{
+ spin_lock_irq(&port->lock);
+ if (!tty_hung_up_p(filp))
+ ++port->count;
+ spin_unlock_irq(&port->lock);
+ tty_port_tty_set(port, tty);
+
+ /*
+ * Do the device-specific open only if the hardware isn't
+ * already initialized. Serialize open and shutdown using the
+ * port mutex.
+ */
+
+ mutex_lock(&port->mutex);
+
+ if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
+ clear_bit(TTY_IO_ERROR, &tty->flags);
+ if (port->ops->activate) {
+ int retval = port->ops->activate(port, tty);
+ if (retval) {
+ mutex_unlock(&port->mutex);
+ return retval;
+ }
+ }
+ set_bit(ASYNCB_INITIALIZED, &port->flags);
+ }
+ mutex_unlock(&port->mutex);
+ return tty_port_block_til_ready(port, tty, filp);
+}
+
+EXPORT_SYMBOL(tty_port_open);
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 22:58:16 +0300