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Commit 18445c4d authored by Rusty Russell's avatar Rusty Russell
Browse files

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: default avatarRusty Russell <rusty@rustcorp.com.au>
parent a586d4f6

drivers/block/virtio_blk.c

+1 −2
Original line number Diff line number Diff line
@@ -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,

drivers/lguest/lguest_device.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/net/virtio_net.c

+8 −7
Original line number Diff line number Diff line
@@ -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 @@ static int virtnet_poll(struct napi_struct *napi, int budget) 
	/* 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;

	}

drivers/virtio/virtio_ring.c

+16 −5
Original line number Diff line number Diff line
@@ -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;

include/linux/virtio.h

+6 −5
Original line number Diff line number Diff line
@@ -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);

};