[PATCH v12 08/40] virtio_ring: split: extract the logic of alloc queue

Xuan Zhuo
2022-07-20T03:05:53Z

Separate the logic of split to create vring queue.

This feature is required for subsequent virtuqueue reset vring.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 68 ++++++++++++++++++++++--------------
1 file changed, 42 insertions(+), 26 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c94c5461e702..c7971438bb2c 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -950,28 +950,19 @@ static void vring_free_split(struct vring_virtqueue_split *vring_split,
kfree(vring_split->desc_extra);
}

-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 int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
+ struct virtio_device *vdev,
+ u32 num,
+ unsigned int vring_align,
+ bool may_reduce_num)
{
- struct virtqueue *vq;
void *queue = NULL;
dma_addr_t dma_addr;
- size_t queue_size_in_bytes;
- struct vring vring;

/* We assume num is a power of 2. */
if (num & (num - 1)) {
dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
- return NULL;
+ return -EINVAL;
}

/* TODO: allocate each queue chunk individually */
@@ -982,11 +973,11 @@ static struct virtqueue *vring_create_virtqueue_split(
if (queue)
break;
if (!may_reduce_num)
- return NULL;
+ return -ENOMEM;
}

if (!num)
- return NULL;
+ return -ENOMEM;

if (!queue) {
/* Try to get a single page. You are my only hope! */
@@ -994,21 +985,46 @@ static struct virtqueue *vring_create_virtqueue_split(
&dma_addr, GFP_KERNEL|__GFP_ZERO);
}
if (!queue)
- return NULL;
+ return -ENOMEM;
+
+ vring_init(&vring_split->vring, num, queue, vring_align);

- queue_size_in_bytes = vring_size(num, vring_align);
- vring_init(&vring, num, queue, vring_align);
+ vring_split->queue_dma_addr = dma_addr;
+ vring_split->queue_size_in_bytes = vring_size(num, vring_align);
+
+ return 0;
+}
+
+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)
+{
+ struct vring_virtqueue_split vring_split = {};
+ struct virtqueue *vq;
+ int err;
+
+ err = vring_alloc_queue_split(&vring_split, vdev, num, vring_align,
+ may_reduce_num);
+ if (err)
+ return NULL;

- vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
- notify, callback, name);
+ vq = __vring_new_virtqueue(index, vring_split.vring, vdev, weak_barriers,
+ context, notify, callback, name);
if (!vq) {
- vring_free_queue(vdev, queue_size_in_bytes, queue,
- dma_addr);
+ vring_free_split(&vring_split, vdev);
return NULL;
}

- to_vvq(vq)->split.queue_dma_addr = dma_addr;
- to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes;
+ to_vvq(vq)->split.queue_dma_addr = vring_split.queue_dma_addr;
+ to_vvq(vq)->split.queue_size_in_bytes = vring_split.queue_size_in_bytes;
to_vvq(vq)->we_own_ring = true;

return vq;
--
2.31.0