virtio-ring: factor out desc_extra allocation

A helper is introduced for the logic of allocating the descriptor
extra data. This will be reused by split virtqueue.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210604055350.58753-4-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Jason Wang 2021-06-04 13:53:46 +08:00 committed by Michael S. Tsirkin
parent 1f28750f2e
commit 5a22242160

View File

@ -1556,6 +1556,25 @@ static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq)
return NULL;
}
static struct vring_desc_extra *vring_alloc_desc_extra(struct vring_virtqueue *vq,
unsigned int num)
{
struct vring_desc_extra *desc_extra;
unsigned int i;
desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra),
GFP_KERNEL);
if (!desc_extra)
return NULL;
memset(desc_extra, 0, num * sizeof(struct vring_desc_extra));
for (i = 0; i < num - 1; i++)
desc_extra[i].next = i + 1;
return desc_extra;
}
static struct virtqueue *vring_create_virtqueue_packed(
unsigned int index,
unsigned int num,
@ -1573,7 +1592,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
struct vring_packed_desc_event *driver, *device;
dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
size_t ring_size_in_bytes, event_size_in_bytes;
unsigned int i;
ring_size_in_bytes = num * sizeof(struct vring_packed_desc);
@ -1657,18 +1675,10 @@ static struct virtqueue *vring_create_virtqueue_packed(
/* Put everything in free lists. */
vq->free_head = 0;
vq->packed.desc_extra = kmalloc_array(num,
sizeof(struct vring_desc_extra),
GFP_KERNEL);
vq->packed.desc_extra = vring_alloc_desc_extra(vq, num);
if (!vq->packed.desc_extra)
goto err_desc_extra;
memset(vq->packed.desc_extra, 0,
num * sizeof(struct vring_desc_extra));
for (i = 0; i < num - 1; i++)
vq->packed.desc_extra[i].next = i + 1;
/* No callback? Tell other side not to bother us. */
if (!callback) {
vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;