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 <rusty@rustcorp.com.au>
Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
This commit is contained in:
Rusty Russell
2009-09-23 22:26:31 -06:00
parent f68d24082e
commit 3c1b27d504
8 changed files with 19 additions and 15 deletions

View File

@@ -65,7 +65,7 @@ static int put_chars(u32 vtermno, const char *buf, int count)
/* add_buf wants a token to identify this buffer: we hand it any
* non-NULL pointer, since there's only ever one buffer. */
if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) == 0) {
if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) {
/* Tell Host to go! */
out_vq->vq_ops->kick(out_vq);
/* Chill out until it's done with the buffer. */
@@ -85,7 +85,7 @@ static void add_inbuf(void)
sg_init_one(sg, inbuf, PAGE_SIZE);
/* We should always be able to add one buffer to an empty queue. */
if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) != 0)
if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) < 0)
BUG();
in_vq->vq_ops->kick(in_vq);
}