[PATCH v9 06/32] virtio_ring: split: extract the logic of alloc queue

[Xuan Zhuo]

On Tue, 12 Apr 2022 11:22:33 +0800, Jason Wang <jasowang at redhat.com> wrote:
>
> 在 2022/4/6 上午11:43, Xuan Zhuo 写道:
> > Separate the logic of split to create vring queue.
> >
> > This feature is required for subsequent virtuqueue reset vring.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> > ---
> >   drivers/virtio/virtio_ring.c | 53 ++++++++++++++++++++++++------------
> >   1 file changed, 36 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index 33fddfb907a6..72d5ae063fa0 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -915,23 +915,15 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
> >   	return NULL;
> >   }
> >
> > -static struct virtqueue *vring_create_virtqueue_split(
> > -	unsigned int index,
> > -	unsigned int num,
> > -	unsigned int vring_align,
> > -	struct virtio_device *vdev,
> > -	bool weak_barriers,
> > -	bool may_reduce_num,
> > -	bool context,
> > -	bool (*notify)(struct virtqueue *),
> > -	void (*callback)(struct virtqueue *),
> > -	const char *name)
> > +static void *vring_alloc_queue_split(struct virtio_device *vdev,
> > +				     dma_addr_t *dma_addr,
> > +				     u32 *n,
> > +				     unsigned int vring_align,
> > +				     bool weak_barriers,
>
>
> This is not used in this function.

The next version will fix it.

Thanks.


>
> Thanks
>
>
> > +				     bool may_reduce_num)
> >   {
> > -	struct virtqueue *vq;
> >   	void *queue = NULL;
> > -	dma_addr_t dma_addr;
> > -	size_t queue_size_in_bytes;
> > -	struct vring vring;
> > +	u32 num = *n;
> >
> >   	/* We assume num is a power of 2. */
> >   	if (num & (num - 1)) {
> > @@ -942,7 +934,7 @@ static struct virtqueue *vring_create_virtqueue_split(
> >   	/* TODO: allocate each queue chunk individually */
> >   	for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) {
> >   		queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
> > -					  &dma_addr,
> > +					  dma_addr,
> >   					  GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> >   		if (queue)
> >   			break;
> > @@ -956,11 +948,38 @@ static struct virtqueue *vring_create_virtqueue_split(
> >   	if (!queue) {
> >   		/* Try to get a single page. You are my only hope! */
> >   		queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
> > -					  &dma_addr, GFP_KERNEL|__GFP_ZERO);
> > +					  dma_addr, GFP_KERNEL|__GFP_ZERO);
> >   	}
> >   	if (!queue)
> >   		return NULL;
> >
> > +	*n = num;
> > +	return queue;
> > +}
> > +
> > +static struct virtqueue *vring_create_virtqueue_split(
> > +	unsigned int index,
> > +	unsigned int num,
> > +	unsigned int vring_align,
> > +	struct virtio_device *vdev,
> > +	bool weak_barriers,
> > +	bool may_reduce_num,
> > +	bool context,
> > +	bool (*notify)(struct virtqueue *),
> > +	void (*callback)(struct virtqueue *),
> > +	const char *name)
> > +{
> > +	size_t queue_size_in_bytes;
> > +	struct virtqueue *vq;
> > +	dma_addr_t dma_addr;
> > +	struct vring vring;
> > +	void *queue;
> > +
> > +	queue = vring_alloc_queue_split(vdev, &dma_addr, &num, vring_align,
> > +					weak_barriers, may_reduce_num);
> > +	if (!queue)
> > +		return NULL;
> > +
> >   	queue_size_in_bytes = vring_size(num, vring_align);
> >   	vring_init(&vring, num, queue, vring_align);
> >
>