diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tty_io.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 54c4ada460ee..739c9c59fc62 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -2088,6 +2088,40 @@ ssize_t redirected_tty_write(struct file *file, const char __user *buf, return tty_write(file, buf, count, ppos); } +void tty_port_init(struct tty_port *port) +{ + memset(port, 0, sizeof(*port)); + init_waitqueue_head(&port->open_wait); + init_waitqueue_head(&port->close_wait); + mutex_init(&port->mutex); +} +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); + if (port->xmit_buf == NULL) + port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); + mutex_unlock(&port->mutex); + if (port->xmit_buf == NULL) + return -ENOMEM; + return 0; +} +EXPORT_SYMBOL(tty_port_alloc_xmit_buf); + +void tty_port_free_xmit_buf(struct tty_port *port) +{ + mutex_lock(&port->mutex); + if (port->xmit_buf != NULL) { + free_page((unsigned long)port->xmit_buf); + port->xmit_buf = NULL; + } + mutex_unlock(&port->mutex); +} +EXPORT_SYMBOL(tty_port_free_xmit_buf); + + static char ptychar[] = "pqrstuvwxyzabcde"; /** |