From 3c1b27d5043086a485f8526353ae9fe37bfa1065 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 23 Sep 2009 22:26:31 -0600 Subject: virtio: make add_buf return capacity remaining This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell Cc: Dinesh Subhraveti --- drivers/virtio/virtio_balloon.c | 2 +- drivers/virtio/virtio_ring.c | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 26b2782..3978923 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -84,7 +84,7 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq) init_completion(&vb->acked); /* We should always be able to add one buffer to an empty queue. */ - if (vq->vq_ops->add_buf(vq, &sg, 1, 0, vb) != 0) + if (vq->vq_ops->add_buf(vq, &sg, 1, 0, vb) < 0) BUG(); vq->vq_ops->kick(vq); diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index a882f26..f536005 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -208,7 +208,11 @@ add_head: pr_debug("Added buffer head %i to %p\n", head, vq); END_USE(vq); - return 0; + + /* If we're indirect, we can fit many (assuming not OOM). */ + if (vq->indirect) + return vq->num_free ? vq->vring.num : 0; + return vq->num_free; } static void vring_kick(struct virtqueue *_vq) -- cgit v1.1