virtio: console: introduce a get_inbuf helper to fetch bufs from in_vq
This makes taking locks around the get_buf vq operation easier, as well
as complements the add_inbuf() operation.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 1dbd46c..df45e5e 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -77,6 +77,22 @@
return NULL;
}
+/* Callers should take appropriate locks */
+static void *get_inbuf(struct port *port)
+{
+ struct port_buffer *buf;
+ struct virtqueue *vq;
+ unsigned int len;
+
+ vq = port->in_vq;
+ buf = vq->vq_ops->get_buf(vq, &len);
+ if (buf) {
+ buf->len = len;
+ buf->offset = 0;
+ }
+ return buf;
+}
+
/*
* Create a scatter-gather list representing our input buffer and put
* it in the queue.
@@ -138,7 +154,6 @@
static int get_chars(u32 vtermno, char *buf, int count)
{
struct port *port;
- unsigned int len;
port = &console;
@@ -147,10 +162,8 @@
/* No more in buffer? See if they've (re)used it. */
if (port->inbuf->offset == port->inbuf->len) {
- if (!port->in_vq->vq_ops->get_buf(port->in_vq, &len))
+ if (!get_inbuf(port))
return 0;
- port->inbuf->offset = 0;
- port->inbuf->len = len;
}
/* You want more than we have to give? Well, try wanting less! */