在 2022/3/8 下午8:34, Xuan Zhuo 写道:
Separate the logic of split to create vring queue.
For the convenience of passing parameters, add a structure
vring_split.
This feature is required for subsequent virtuqueue reset vring.
Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 74 +++++++++++++++++++++++++-----------
1 file changed, 51 insertions(+), 23 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b87130c8f312..d32793615451 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -85,6 +85,13 @@ struct vring_desc_extra {
u16 next; /* The next desc state in a list. */
};
+struct vring_split {
+ void *queue;
+ dma_addr_t dma_addr;
+ size_t queue_size_in_bytes;
+ struct vring vring;
+};
So this structure will be only used in vring_create_vring_split() which
seems not that useful.
More see below.
+
struct vring_virtqueue {
struct virtqueue vq;
@@ -915,28 +922,21 @@ 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 int vring_create_vring_split(struct vring_split *vring,
+ struct virtio_device *vdev,
+ unsigned int vring_align,
+ bool weak_barriers,
+ bool may_reduce_num,
+ u32 num)
I'd rename this as vring_alloc_queue_split() and let it simply return
the address of queue like vring_alloc_queue().
And let it simple accept dma_addr_t *dma_adder instead of vring_split.
{
- 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 */
@@ -947,11 +947,11 @@ 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! */
@@ -959,21 +959,49 @@ static struct virtqueue *vring_create_virtqueue_split(
&dma_addr, GFP_KERNEL|__GFP_ZERO);
}
if (!queue)
- return NULL;
+ return -ENOMEM;
queue_size_in_bytes = vring_size(num, vring_align);
- vring_init(&vring, num, queue, vring_align);
+ vring_init(&vring->vring, num, queue, vring_align);
It's better to move this to its caller (vring_create_virtqueue_split),
so we have rather simple logic below:
+
+ vring->dma_addr = dma_addr;
+ vring->queue = queue;
+ vring->queue_size_in_bytes = queue_size_in_bytes;
+
+ 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_split vring;
+ struct virtqueue *vq;
+ int err;
+
+ err = vring_create_vring_split(&vring, vdev, vring_align, weak_barriers,
+ may_reduce_num, num);
+ if (err)
+ return NULL;
queue = vring_alloc_queue_split(vdev, &dma_addr, ...);
if (!queue)
return -ENOMEM;
vring_init();
...
Thanks
- vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
+ vq = __vring_new_virtqueue(index, vring.vring, vdev, weak_barriers,
context,
notify, callback, name);
if (!vq) {
- vring_free_queue(vdev, queue_size_in_bytes, queue,
- dma_addr);
+ vring_free_queue(vdev, vring.queue_size_in_bytes, vring.queue,
+ vring.dma_addr);
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.dma_addr;
+ to_vvq(vq)->split.queue_size_in_bytes = vring.queue_size_in_bytes;
to_vvq(vq)->we_own_ring = true;
return vq;
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