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authorAmit Shah <amit.shah@redhat.com>2011-09-14 11:36:43 +0400
committerRusty Russell <rusty@rustcorp.com.au>2011-11-02 05:11:00 +0400
commitd25a9ddae93ca97aa03fdab1363baf0e0c35d960 (patch)
treefea9bd4041716248fdfd8db78bab715f1d907670 /drivers/char/virtio_console.c
parentdefde66996476295dc7b1b60ea318965f8c3ad86 (diff)
downloadlinux-d25a9ddae93ca97aa03fdab1363baf0e0c35d960.tar.xz
virtio: console: make get_inbuf() return port->inbuf if present
Instead of pulling in a buffer from the vq each time it's called, get_inbuf() now checks if the current active buffer, in port->inbuf is valid. If it is, just returns a pointer to it. This ends up simplifying a lot of code calling get_inbuf() since the check for port->inbuf being valid was done by all the callers. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/char/virtio_console.c')
-rw-r--r--drivers/char/virtio_console.c22
1 files changed, 8 insertions, 14 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 3516aeb7f06c..cb5edf33bebf 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -351,11 +351,12 @@ fail:
static struct port_buffer *get_inbuf(struct port *port)
{
struct port_buffer *buf;
- struct virtqueue *vq;
unsigned int len;
- vq = port->in_vq;
- buf = virtqueue_get_buf(vq, &len);
+ if (port->inbuf)
+ return port->inbuf;
+
+ buf = virtqueue_get_buf(port->in_vq, &len);
if (buf) {
buf->len = len;
buf->offset = 0;
@@ -418,18 +419,12 @@ static bool port_has_data(struct port *port)
unsigned long flags;
bool ret;
+ ret = false;
spin_lock_irqsave(&port->inbuf_lock, flags);
- if (port->inbuf) {
- ret = true;
- goto out;
- }
port->inbuf = get_inbuf(port);
- if (port->inbuf) {
+ if (port->inbuf)
ret = true;
- goto out;
- }
- ret = false;
-out:
+
spin_unlock_irqrestore(&port->inbuf_lock, flags);
return ret;
}
@@ -1489,8 +1484,7 @@ static void in_intr(struct virtqueue *vq)
return;
spin_lock_irqsave(&port->inbuf_lock, flags);
- if (!port->inbuf)
- port->inbuf = get_inbuf(port);
+ port->inbuf = get_inbuf(port);
/*
* Don't queue up data when port is closed. This condition