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

Xuan Zhuo
2022-04-06T13:59:55Z

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 | 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,
+ 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);

--
2.31.0