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>
This commit is contained in:
Amit Shah 2010-01-18 19:15:03 +05:30 committed by Rusty Russell
parent e27b519807
commit a3cde44908
1 changed files with 17 additions and 4 deletions

View File

@ -77,6 +77,22 @@ fail:
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 put_chars(u32 vtermno, const char *buf, int count)
static int get_chars(u32 vtermno, char *buf, int count)
{
struct port *port;
unsigned int len;
port = &console;
@ -147,10 +162,8 @@ static int get_chars(u32 vtermno, char *buf, int count)
/* 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! */