From 6f67048cd010afe19d79d821f16055d9c704c6f0 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 16 Jul 2008 21:53:41 +0100 Subject: tty: Introduce a tty_port common structure Every tty driver has its own concept of a port structure and because they all differ we cannot extract commonality. Begin fixing this by creating a structure drivers can elect to use so that over time we can push fields into this and create commonality and then introduce common methods. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/char/tty_io.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) (limited to 'drivers') 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"; /** -- cgit v1.2.3