[PATCH v12 09/40] virtio_ring: split: extract the logic of alloc state and extra

Xuan Zhuo
2022-07-20T03:06:30Z

Separate the logic of creating desc_state, desc_extra, and subsequent
patches will call it independently.

Since only the structure vring is passed into __vring_new_virtqueue(),
when creating the function vring_alloc_state_extra_split(), we prefer to
use vring_virtqueue_split as a parameter, and it will be more convenient
to pass vring_virtqueue_split to some subsequent functions.

So a new vring_virtqueue_split variable is added in
__vring_new_virtqueue().

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 54 +++++++++++++++++++++++++-----------
1 file changed, 38 insertions(+), 16 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c7971438bb2c..ef2077e8b38d 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -204,6 +204,7 @@ struct vring_virtqueue {
#endif
};

+static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num);

/*
* Helpers.
@@ -939,6 +940,32 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
return NULL;
}

+static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split)
+{
+ struct vring_desc_state_split *state;
+ struct vring_desc_extra *extra;
+ u32 num = vring_split->vring.num;
+
+ state = kmalloc_array(num, sizeof(struct vring_desc_state_split), GFP_KERNEL);
+ if (!state)
+ goto err_state;
+
+ extra = vring_alloc_desc_extra(num);
+ if (!extra)
+ goto err_extra;
+
+ memset(state, 0, num * sizeof(struct vring_desc_state_split));
+
+ vring_split->desc_state = state;
+ vring_split->desc_extra = extra;
+ return 0;
+
+err_extra:
+ kfree(state);
+err_state:
+ return -ENOMEM;
+}
+
static void vring_free_split(struct vring_virtqueue_split *vring_split,
struct virtio_device *vdev)
{
@@ -2233,7 +2260,9 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
void (*callback)(struct virtqueue *),
const char *name)
{
+ struct vring_virtqueue_split vring_split = {};
struct vring_virtqueue *vq;
+ int err;

if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
return NULL;
@@ -2274,30 +2303,23 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->split.avail_flags_shadow);
}

- vq->split.desc_state = kmalloc_array(vring.num,
- sizeof(struct vring_desc_state_split), GFP_KERNEL);
- if (!vq->split.desc_state)
- goto err_state;
+ vring_split.vring = vring;

- vq->split.desc_extra = vring_alloc_desc_extra(vring.num);
- if (!vq->split.desc_extra)
- goto err_extra;
+ err = vring_alloc_state_extra_split(&vring_split);
+ if (err) {
+ kfree(vq);
+ return NULL;
+ }

- memset(vq->split.desc_state, 0, vring.num *
- sizeof(struct vring_desc_state_split));
+ vq->split.desc_state = vring.desc_state;
+ vq->split.desc_extra = vring.desc_extra;

- virtqueue_init(vq, vq->split.vring.num);
+ virtqueue_init(vq, vring_split.vring.num);

spin_lock(&vdev->vqs_list_lock);
list_add_tail(&vq->vq.list, &vdev->vqs);
spin_unlock(&vdev->vqs_list_lock);
return &vq->vq;
-
-err_extra:
- kfree(vq->split.desc_state);
-err_state:
- kfree(vq);
- return NULL;
}
EXPORT_SYMBOL_GPL(__vring_new_virtqueue);

--
2.31.0