From 3c1b27d5043086a485f8526353ae9fe37bfa1065 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 23 Sep 2009 22:26:31 -0600 Subject: [PATCH] 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/block/virtio_blk.c | 2 +- drivers/char/hw_random/virtio-rng.c | 2 +- drivers/char/virtio_console.c | 4 ++-- drivers/net/virtio_net.c | 14 +++++++------- drivers/virtio/virtio_balloon.c | 2 +- drivers/virtio/virtio_ring.c | 6 +++++- include/linux/virtio.h | 2 +- net/9p/trans_virtio.c | 2 +- 8 files changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index aa1a3d5a3e2b..d739ee4201f9 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -139,7 +139,7 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, } } - if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr)) { + if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr) < 0) { mempool_free(vbr, vblk->pool); return false; } diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 32216b623248..b6c24dcc987d 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -51,7 +51,7 @@ static void register_buffer(void) sg_init_one(&sg, random_data+data_left, RANDOM_DATA_SIZE-data_left); /* There should always be room for one buffer. */ - if (vq->vq_ops->add_buf(vq, &sg, 0, 1, random_data) != 0) + if (vq->vq_ops->add_buf(vq, &sg, 0, 1, random_data) < 0) BUG(); vq->vq_ops->kick(vq); } diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index c74dacfa6795..a035ae39a359 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -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); } diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 32266fb89c20..fbf04a553f5a 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -320,7 +320,7 @@ static bool try_fill_recv_maxbufs(struct virtnet_info *vi, gfp_t gfp) skb_queue_head(&vi->recv, skb); err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb); - if (err) { + if (err < 0) { skb_unlink(skb, &vi->recv); trim_pages(vi, skb); kfree_skb(skb); @@ -373,7 +373,7 @@ static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) skb_queue_head(&vi->recv, skb); err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb); - if (err) { + if (err < 0) { skb_unlink(skb, &vi->recv); kfree_skb(skb); break; @@ -527,7 +527,7 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb); - if (!err && !vi->free_in_tasklet) + if (err >= 0 && !vi->free_in_tasklet) mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10)); return err; @@ -538,7 +538,7 @@ static void xmit_tasklet(unsigned long data) struct virtnet_info *vi = (void *)data; netif_tx_lock_bh(vi->dev); - if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) { + if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) >= 0) { vi->svq->vq_ops->kick(vi->svq); vi->last_xmit_skb = NULL; } @@ -557,7 +557,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) /* If we has a buffer left over from last time, send it now. */ if (unlikely(vi->last_xmit_skb) && - xmit_skb(vi, vi->last_xmit_skb) != 0) + xmit_skb(vi, vi->last_xmit_skb) < 0) goto stop_queue; vi->last_xmit_skb = NULL; @@ -565,7 +565,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) /* Put new one in send queue and do transmit */ if (likely(skb)) { __skb_queue_head(&vi->send, skb); - if (xmit_skb(vi, skb) != 0) { + if (xmit_skb(vi, skb) < 0) { vi->last_xmit_skb = skb; skb = NULL; goto stop_queue; @@ -668,7 +668,7 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, sg_set_buf(&sg[i + 1], sg_virt(s), s->length); sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); - BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi)); + BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0); vi->cvq->vq_ops->kick(vi->cvq); diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 26b278264796..39789232646d 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 a882f2606515..f53600580726 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -208,7 +208,11 @@ static int vring_add_buf(struct virtqueue *_vq, 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) diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 4fca4f5440ba..057a2e010758 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -34,7 +34,7 @@ struct virtqueue { * out_num: the number of sg readable by other side * in_num: the number of sg which are writable (after readable ones) * data: the token identifying the buffer. - * Returns 0 or an error. + * Returns remaining capacity of queue (sg segments) or a negative error. * @kick: update after add_buf * vq: the struct virtqueue * After one or more add_buf calls, invoke this to kick the other side. diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 9bf0b737aa51..53c139d31a21 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -200,7 +200,7 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req) req->status = REQ_STATUS_SENT; - if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc)) { + if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc) < 0) { P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc add_buf returned failure"); return -EIO; -- GitLab