virtio: explicit enable_cb/disable_cb rather than callback return.

It seems that virtio_net wants to disable callbacks (interrupts) before
calling netif_rx_schedule(), so we can't use the return value to do so.

Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback
now returns void, rather than a boolean.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2008-02-04 23:49:57 -05:00
parent a586d4f601
commit 18445c4d50
8 changed files with 35 additions and 25 deletions

View File

@ -36,7 +36,7 @@ struct virtblk_req
struct virtio_blk_inhdr in_hdr;
};
static bool blk_done(struct virtqueue *vq)
static void blk_done(struct virtqueue *vq)
{
struct virtio_blk *vblk = vq->vdev->priv;
struct virtblk_req *vbr;
@ -65,7 +65,6 @@ static bool blk_done(struct virtqueue *vq)
/* In case queue is stopped waiting for more buffers. */
blk_start_queue(vblk->disk->queue);
spin_unlock_irqrestore(&vblk->lock, flags);
return true;
}
static bool do_req(struct request_queue *q, struct virtio_blk *vblk,

View File

@ -191,7 +191,7 @@ static void lg_notify(struct virtqueue *vq)
* So we provide devices with a "find virtqueue and set it up" function. */
static struct virtqueue *lg_find_vq(struct virtio_device *vdev,
unsigned index,
bool (*callback)(struct virtqueue *vq))
void (*callback)(struct virtqueue *vq))
{
struct lguest_device *ldev = to_lgdev(vdev);
struct lguest_vq_info *lvq;

View File

@ -52,13 +52,12 @@ static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
}
static bool skb_xmit_done(struct virtqueue *rvq)
static void skb_xmit_done(struct virtqueue *rvq)
{
struct virtnet_info *vi = rvq->vdev->priv;
/* In case we were waiting for output buffers. */
netif_wake_queue(vi->dev);
return true;
}
static void receive_skb(struct net_device *dev, struct sk_buff *skb,
@ -161,12 +160,14 @@ static void try_fill_recv(struct virtnet_info *vi)
vi->rvq->vq_ops->kick(vi->rvq);
}
static bool skb_recv_done(struct virtqueue *rvq)
static void skb_recv_done(struct virtqueue *rvq)
{
struct virtnet_info *vi = rvq->vdev->priv;
netif_rx_schedule(vi->dev, &vi->napi);
/* Suppress further interrupts. */
return false;
/* Schedule NAPI, Suppress further interrupts if successful. */
if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
rvq->vq_ops->disable_cb(rvq);
__netif_rx_schedule(vi->dev, &vi->napi);
}
}
static int virtnet_poll(struct napi_struct *napi, int budget)
@ -192,7 +193,7 @@ again:
/* Out of packets? */
if (received < budget) {
netif_rx_complete(vi->dev, napi);
if (unlikely(!vi->rvq->vq_ops->restart(vi->rvq))
if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
&& netif_rx_reschedule(vi->dev, napi))
goto again;
}

View File

@ -220,7 +220,17 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
return ret;
}
static bool vring_restart(struct virtqueue *_vq)
static void vring_disable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
START_USE(vq);
BUG_ON(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT);
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
END_USE(vq);
}
static bool vring_enable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@ -254,8 +264,8 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
return IRQ_HANDLED;
pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
if (vq->vq.callback && !vq->vq.callback(&vq->vq))
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
if (vq->vq.callback)
vq->vq.callback(&vq->vq);
return IRQ_HANDLED;
}
@ -264,7 +274,8 @@ static struct virtqueue_ops vring_vq_ops = {
.add_buf = vring_add_buf,
.get_buf = vring_get_buf,
.kick = vring_kick,
.restart = vring_restart,
.disable_cb = vring_disable_cb,
.enable_cb = vring_enable_cb,
.shutdown = vring_shutdown,
};
@ -272,7 +283,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *),
bool (*callback)(struct virtqueue *))
void (*callback)(struct virtqueue *))
{
struct vring_virtqueue *vq;
unsigned int i;

View File

@ -11,15 +11,13 @@
/**
* virtqueue - a queue to register buffers for sending or receiving.
* @callback: the function to call when buffers are consumed (can be NULL).
* If this returns false, callbacks are suppressed until vq_ops->restart
* is called.
* @vdev: the virtio device this queue was created for.
* @vq_ops: the operations for this virtqueue (see below).
* @priv: a pointer for the virtqueue implementation to use.
*/
struct virtqueue
{
bool (*callback)(struct virtqueue *vq);
void (*callback)(struct virtqueue *vq);
struct virtio_device *vdev;
struct virtqueue_ops *vq_ops;
void *priv;
@ -41,7 +39,9 @@ struct virtqueue
* vq: the struct virtqueue we're talking about.
* len: the length written into the buffer
* Returns NULL or the "data" token handed to add_buf.
* @restart: restart callbacks after callback returned false.
* @disable_cb: disable callbacks
* vq: the struct virtqueue we're talking about.
* @enable_cb: restart callbacks after disable_cb.
* vq: the struct virtqueue we're talking about.
* This returns "false" (and doesn't re-enable) if there are pending
* buffers in the queue, to avoid a race.
@ -65,7 +65,8 @@ struct virtqueue_ops {
void *(*get_buf)(struct virtqueue *vq, unsigned int *len);
bool (*restart)(struct virtqueue *vq);
void (*disable_cb)(struct virtqueue *vq);
bool (*enable_cb)(struct virtqueue *vq);
void (*shutdown)(struct virtqueue *vq);
};

View File

@ -61,7 +61,7 @@ struct virtio_config_ops
void (*set_status)(struct virtio_device *vdev, u8 status);
struct virtqueue *(*find_vq)(struct virtio_device *vdev,
unsigned index,
bool (*callback)(struct virtqueue *));
void (*callback)(struct virtqueue *));
void (*del_vq)(struct virtqueue *vq);
};

View File

@ -114,7 +114,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *vq),
bool (*callback)(struct virtqueue *vq));
void (*callback)(struct virtqueue *vq));
void vring_del_virtqueue(struct virtqueue *vq);
irqreturn_t vring_interrupt(int irq, void *_vq);

View File

@ -199,14 +199,12 @@ static void p9_virtio_close(struct p9_trans *trans)
kfree(trans);
}
static bool p9_virtio_intr(struct virtqueue *q)
static void p9_virtio_intr(struct virtqueue *q)
{
struct virtio_chan *chan = q->vdev->priv;
P9_DPRINTK(P9_DEBUG_TRANS, "9p poll_wakeup: %p\n", &chan->wq);
wake_up_interruptible(&chan->wq);
return true;
}
static int p9_virtio_probe(struct virtio_device *dev)