Commit 7c5e9ed0 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Rusty Russell
Browse files

virtio_ring: remove a level of indirection 



We have a single virtqueue_ops implementation,
and it seems unlikely we'll get another one
at this point. So let's remove an unnecessary
level of indirection: it would be very easy to
re-add it if another implementation surfaces.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 1915a712

drivers/virtio/virtio_ring.c

+16 −20
Original line number Diff line number Diff line
@@ -155,7 +155,7 @@ static int vring_add_indirect(struct vring_virtqueue *vq, 
	return head;

}



static int vring_add_buf(struct virtqueue *_vq,

int virtqueue_add_buf(struct virtqueue *_vq,

		  struct scatterlist sg[],

		  unsigned int out,

		  unsigned int in,
@@ -232,8 +232,9 @@ add_head: 
		return vq->num_free ? vq->vring.num : 0;

	return vq->num_free;

}

EXPORT_SYMBOL_GPL(virtqueue_add_buf);



static void vring_kick(struct virtqueue *_vq)

void virtqueue_kick(struct virtqueue *_vq)

{

	struct vring_virtqueue *vq = to_vvq(_vq);

	START_USE(vq);
@@ -253,6 +254,7 @@ static void vring_kick(struct virtqueue *_vq) 


	END_USE(vq);

}

EXPORT_SYMBOL_GPL(virtqueue_kick);



static void detach_buf(struct vring_virtqueue *vq, unsigned int head)

{
@@ -284,7 +286,7 @@ static inline bool more_used(const struct vring_virtqueue *vq) 
	return vq->last_used_idx != vq->vring.used->idx;

}



static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)

void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)

{

	struct vring_virtqueue *vq = to_vvq(_vq);

	void *ret;
@@ -325,15 +327,17 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len) 
	END_USE(vq);

	return ret;

}

EXPORT_SYMBOL_GPL(virtqueue_get_buf);



static void vring_disable_cb(struct virtqueue *_vq)

void virtqueue_disable_cb(struct virtqueue *_vq)

{

	struct vring_virtqueue *vq = to_vvq(_vq);



	vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;

}

EXPORT_SYMBOL_GPL(virtqueue_disable_cb);



static bool vring_enable_cb(struct virtqueue *_vq)

bool virtqueue_enable_cb(struct virtqueue *_vq)

{

	struct vring_virtqueue *vq = to_vvq(_vq);
@@ -351,8 +355,9 @@ static bool vring_enable_cb(struct virtqueue *_vq) 
	END_USE(vq);

	return true;

}

EXPORT_SYMBOL_GPL(virtqueue_enable_cb);



static void *vring_detach_unused_buf(struct virtqueue *_vq)

void *virtqueue_detach_unused_buf(struct virtqueue *_vq)

{

	struct vring_virtqueue *vq = to_vvq(_vq);

	unsigned int i;
@@ -375,6 +380,7 @@ static void *vring_detach_unused_buf(struct virtqueue *_vq) 
	END_USE(vq);

	return NULL;

}

EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);



irqreturn_t vring_interrupt(int irq, void *_vq)

{
@@ -396,15 +402,6 @@ irqreturn_t vring_interrupt(int irq, void *_vq) 
}

EXPORT_SYMBOL_GPL(vring_interrupt);



static struct virtqueue_ops vring_vq_ops = {

	.add_buf = vring_add_buf,

	.get_buf = vring_get_buf,

	.kick = vring_kick,

	.disable_cb = vring_disable_cb,

	.enable_cb = vring_enable_cb,

	.detach_unused_buf = vring_detach_unused_buf,

};



struct virtqueue *vring_new_virtqueue(unsigned int num,

				      unsigned int vring_align,

				      struct virtio_device *vdev,
@@ -429,7 +426,6 @@ struct virtqueue *vring_new_virtqueue(unsigned int num, 
	vring_init(&vq->vring, num, pages, vring_align);

	vq->vq.callback = callback;

	vq->vq.vdev = vdev;

	vq->vq.vq_ops = &vring_vq_ops;

	vq->vq.name = name;

	vq->notify = notify;

	vq->broken = false;

include/linux/virtio.h

+18 −53
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
 * @callback: the function to call when buffers are consumed (can be NULL).

 * @name: the name of this virtqueue (mainly for debugging)

 * @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 {
@@ -22,94 +21,60 @@ struct virtqueue { 
	void (*callback)(struct virtqueue *vq);

	const char *name;

	struct virtio_device *vdev;

	struct virtqueue_ops *vq_ops;

	void *priv;

};



/**

 * virtqueue_ops - operations for virtqueue abstraction layer

 * @add_buf: expose buffer to other end

 * operations for virtqueue

 * virtqueue_add_buf: expose buffer to other end

 *	vq: the struct virtqueue we're talking about.

 *	sg: the description of the buffer(s).

 *	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 remaining capacity of queue (sg segments) or a negative error.

 * @kick: update after add_buf

 * virtqueue_kick: update after add_buf

 *	vq: the struct virtqueue

 *	After one or more add_buf calls, invoke this to kick the other side.

 * @get_buf: get the next used buffer

 * virtqueue_get_buf: get the next used buffer

 *	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.

 * @disable_cb: disable callbacks

 * virtqueue_disable_cb: disable callbacks

 *	vq: the struct virtqueue we're talking about.

 *	Note that this is not necessarily synchronous, hence unreliable and only

 *	useful as an optimization.

 * @enable_cb: restart callbacks after disable_cb.

 * virtqueue_enable_cb: restart callbacks after disable_cb.

 *	vq: the struct virtqueue we're talking about.

 *	This re-enables callbacks; it returns "false" if there are pending

 *	buffers in the queue, to detect a possible race between the driver

 *	checking for more work, and enabling callbacks.

 * @detach_unused_buf: detach first unused buffer

 * virtqueue_detach_unused_buf: detach first unused buffer

 * 	vq: the struct virtqueue we're talking about.

 * 	Returns NULL or the "data" token handed to add_buf

 *

 * Locking rules are straightforward: the driver is responsible for

 * locking.  No two operations may be invoked simultaneously, with the exception

 * of @disable_cb.

 * of virtqueue_disable_cb.

 *

 * All operations can be called in any context.

 */

struct virtqueue_ops {

	int (*add_buf)(struct virtqueue *vq,

		       struct scatterlist sg[],

		       unsigned int out_num,

		       unsigned int in_num,

		       void *data);



	void (*kick)(struct virtqueue *vq);



	void *(*get_buf)(struct virtqueue *vq, unsigned int *len);



	void (*disable_cb)(struct virtqueue *vq);

	bool (*enable_cb)(struct virtqueue *vq);

	void *(*detach_unused_buf)(struct virtqueue *vq);

};



static inline int virtqueue_add_buf(struct virtqueue *vq,

int virtqueue_add_buf(struct virtqueue *vq,

		      struct scatterlist sg[],

		      unsigned int out_num,

		      unsigned int in_num,

				    void *data)

{

	return vq->vq_ops->add_buf(vq, sg, out_num, in_num, data);

}

		      void *data);



static inline int void virtqueue_kick(struct virtqueue *vq)

{

	return vq->vq_ops->kick(vq);

}

void virtqueue_kick(struct virtqueue *vq);



static inline void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len)

{

	return vq->vq_ops->get_buf(vq, len);

}

void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);



static inline void virtqueue_disable_cb(struct virtqueue *vq)

{

	vq->vq_ops->disable_cb(vq);

}

void virtqueue_disable_cb(struct virtqueue *vq);



static inline bool virtqueue_enable_cb(struct virtqueue *vq)

{

	return vq->vq_ops->enable_cb(vq);

}

bool virtqueue_enable_cb(struct virtqueue *vq);



static inline void *virtqueue_detach_unused_buf(struct virtqueue *vq)

{

	return vq->vq_ops->detach_unused_buf(vq);

}

void *virtqueue_detach_unused_buf(struct virtqueue *vq);



/**

 * virtio_device - representation of a device using virtio

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