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virtio_ring: split: extract the logic of alloc queue

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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>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-11-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Xuan Zhuo 2022-08-01 14:38:30 +08:00 committed by Michael S. Tsirkin
parent 89f05d94a3
commit c2d87fe68d
1 changed files with 52 additions and 37 deletions
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89
drivers/virtio/virtio_ring.c
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@ -948,6 +948,51 @@ static void vring_free_split(struct vring_virtqueue_split *vring_split,
kfree(vring_split->desc_extra);
}
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)
{
void *queue = NULL;
dma_addr_t dma_addr;
/* We assume num is a power of 2. */
if (num & (num - 1)) {
dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
return -EINVAL;
}
/* 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,
GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
if (queue)
break;
if (!may_reduce_num)
return -ENOMEM;
}
if (!num)
return -ENOMEM;
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);
}
if (!queue)
return -ENOMEM;
vring_init(&vring_split->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,
@ -962,52 +1007,22 @@ static struct virtqueue *vring_create_virtqueue_split(
{
struct vring_virtqueue_split vring_split = {};
struct virtqueue *vq;
void *queue = NULL;
dma_addr_t dma_addr;
size_t queue_size_in_bytes;
struct vring vring;
int err;
/* We assume num is a power of 2. */
if (num & (num - 1)) {
dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
err = vring_alloc_queue_split(&vring_split, vdev, num, vring_align,
may_reduce_num);
if (err)
return NULL;
}
/* 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,
GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
if (queue)
break;
if (!may_reduce_num)
return NULL;
}
if (!num)
return NULL;
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);
}
if (!queue)
return NULL;
queue_size_in_bytes = vring_size(num, vring_align);
vring_init(&vring_split.vring, num, queue, vring_align);
vq = __vring_new_virtqueue(index, &vring_split, 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;