TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index e1257d1..3ea5408 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -699,7 +699,6 @@
 			       bool readfifo)
 {
 	struct tty_port *port = &uap->port.state->port;
-	struct tty_struct *tty = port->tty;
 	struct pl011_sgbuf *sgbuf = use_buf_b ?
 		&uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
 	struct device *dev = uap->dmarx.chan->device->dev;
@@ -754,7 +753,7 @@
 	dev_vdbg(uap->port.dev,
 		 "Took %d chars from DMA buffer and %d chars from the FIFO\n",
 		 dma_count, fifotaken);
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(port);
 	spin_lock(&uap->port.lock);
 }
 
@@ -1076,12 +1075,10 @@
 
 static void pl011_rx_chars(struct uart_amba_port *uap)
 {
-	struct tty_struct *tty = uap->port.state->port.tty;
-
 	pl011_fifo_to_tty(uap);
 
 	spin_unlock(&uap->port.lock);
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(&uap->port.state->port);
 	/*
 	 * If we were temporarily out of DMA mode for a while,
 	 * attempt to switch back to DMA mode again.