As discussed:
http://lore.kernel.org/all/CACGkMEug-=C+VQhkMYSgUKMC==04m7-uem_yc21bggkkzh8...@mail.gmail.com
When the vq is premapped mode, the driver manages the dma
info is a good way.
So this commit make the virtio core not to store the dma
info and release the memory which is used to store the dma
info.
If the use_dma_api is false, the memory is also not allocated.
Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 100 ++++++++++++++++++++++++++++++-----
1 file changed, 87 insertions(+), 13 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 81a8c2b70af1..f5a72d22c838 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -94,12 +94,15 @@ struct vring_desc_state_packed {
};
struct vring_desc_extra {
- dma_addr_t addr; /* Descriptor DMA addr. */
- u32 len; /* Descriptor length. */
u16 flags; /* Descriptor flags. */
u16 next; /* The next desc state in a list. */
};
+struct vring_desc_dma {
+ dma_addr_t addr; /* Descriptor DMA addr. */
+ u32 len; /* Descriptor length. */
+};
+
struct vring_virtqueue_split {
/* Actual memory layout for this queue. */
struct vring vring;
@@ -116,6 +119,7 @@ struct vring_virtqueue_split {
/* Per-descriptor state. */
struct vring_desc_state_split *desc_state;
struct vring_desc_extra *desc_extra;
+ struct vring_desc_dma *desc_dma;
/* DMA address and size information */
dma_addr_t queue_dma_addr;
@@ -156,6 +160,7 @@ struct vring_virtqueue_packed {
/* Per-descriptor state. */
struct vring_desc_state_packed *desc_state;
struct vring_desc_extra *desc_extra;
+ struct vring_desc_dma *desc_dma;
/* DMA address and size information */
dma_addr_t ring_dma_addr;
@@ -470,13 +475,14 @@ static unsigned int vring_unmap_one_split(const struct
vring_virtqueue *vq,
unsigned int i)
{
struct vring_desc_extra *extra = vq->split.desc_extra;
+ struct vring_desc_dma *dma = vq->split.desc_dma;
u16 flags;
flags = extra[i].flags;
dma_unmap_page(vring_dma_dev(vq),
- extra[i].addr,
- extra[i].len,
+ dma[i].addr,
+ dma[i].len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
@@ -533,8 +539,11 @@ static inline unsigned int virtqueue_add_desc_split(struct
virtqueue *vq,
next = extra[i].next;
desc[i].next = cpu_to_virtio16(vq->vdev, next);
- extra[i].addr = addr;
- extra[i].len = len;
+ if (vring->split.desc_dma) {
+ vring->split.desc_dma[i].addr = addr;
+ vring->split.desc_dma[i].len = len;
+ }
+
extra[i].flags = flags;
} else
next = virtio16_to_cpu(vq->vdev, desc[i].next);
@@ -1070,6 +1079,23 @@ static void virtqueue_vring_attach_split(struct
vring_virtqueue *vq,
vq->free_head = 0;
}
+static int vring_alloc_dma_split(struct vring_virtqueue_split *vring_split,
+ bool need_unmap)
+{
+ u32 num = vring_split->vring.num;
+ struct vring_desc_dma *dma;
+
+ if (!need_unmap)
+ return 0;
+
+ dma = kmalloc_array(num, sizeof(struct vring_desc_dma), GFP_KERNEL);
+ if (!dma)
+ return -ENOMEM;
+
+ vring_split->desc_dma = dma;
+ return 0;
+}
+
static int vring_alloc_state_extra_split(struct vring_virtqueue_split
*vring_split)
{
struct vring_desc_state_split *state;
@@ -1106,6 +1132,7 @@ static void vring_free_split(struct vring_virtqueue_split
*vring_split,
kfree(vring_split->desc_state);
kfree(vring_split->desc_extra);
+ kfree(vring_split->desc_dma);
}
static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
@@ -1207,6 +1234,10 @@ static int virtqueue_resize_split(struct virtqueue *_vq,
u32 num)
if (err)
goto err_state_extra;
+ err = vring_alloc_dma_split(&vring_split, vring_need_unmap_buffer(vq));
+ if (err)
+ goto err_state_extra;
+
vring_free(&vq->vq);
virtqueue_vring_init_split(&vring_split, vq);
@@ -1239,14 +1270,16 @@ static u16 packed_last_used(u16 last_used_idx)
/* caller must check vring_need_unmap_buffer() */
static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
- const struct vring_desc_extra *extra)
+ unsigned int i)
{
+ const struct vring_desc_extra *extra = &vq->packed.desc_extra[i];
+ const struct vring_desc_dma *dma = &vq->packed.desc_dma[i];
u16 flags;
flags = extra->flags;
dma_unmap_page(vring_dma_dev(vq),
- extra->addr, extra->len,
+ dma->addr, dma->len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
@@ -1497,8 +1530,8 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
desc[i].id = cpu_to_le16(id);
if (vring_need_unmap_buffer(vq)) {
- vq->packed.desc_extra[curr].addr = addr;
- vq->packed.desc_extra[curr].len = sg->length;
+ vq->packed.desc_dma[curr].addr = addr;
+ vq->packed.desc_dma[curr].len = sg->length;
}
vq->packed.desc_extra[curr].flags = le16_to_cpu(flags);
@@ -1557,7 +1590,7 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
for (n = 0; n < total_sg; n++) {
if (i == err_idx)
break;
- vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]);
+ vring_unmap_extra_packed(vq, curr);
curr = vq->packed.desc_extra[curr].next;
i++;
if (i >= vq->packed.vring.num)
@@ -1638,8 +1671,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
if (vring_need_unmap_buffer(vq)) {
curr = id;
for (i = 0; i < state->num; i++) {
- vring_unmap_extra_packed(vq,
-
&vq->packed.desc_extra[curr]);
+ vring_unmap_extra_packed(vq, curr);
curr = vq->packed.desc_extra[curr].next;
}
}
@@ -1952,6 +1984,7 @@ static void vring_free_packed(struct
vring_virtqueue_packed *vring_packed,
kfree(vring_packed->desc_state);
kfree(vring_packed->desc_extra);
+ kfree(vring_packed->desc_dma);
}
static int vring_alloc_queue_packed(struct vring_virtqueue_packed
*vring_packed,
@@ -2008,6 +2041,23 @@ static int vring_alloc_queue_packed(struct
vring_virtqueue_packed *vring_packed,
return -ENOMEM;
}
+static int vring_alloc_dma_packed(struct vring_virtqueue_packed *vring_packed,
+ bool need_unmap)
+{
+ u32 num = vring_packed->vring.num;
+ struct vring_desc_dma *dma;
+
+ if (!need_unmap)
+ return 0;
+
+ dma = kmalloc_array(num, sizeof(struct vring_desc_dma), GFP_KERNEL);
+ if (!dma)
+ return -ENOMEM;
+
+ vring_packed->desc_dma = dma;
+ return 0;
+}
+
static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed
*vring_packed)
{
struct vring_desc_state_packed *state;
@@ -2120,6 +2170,10 @@ static struct virtqueue
*vring_create_virtqueue_packed(struct virtio_device *vde
if (err)
goto err_state_extra;
+ err = vring_alloc_dma_packed(&vring_packed,
vring_need_unmap_buffer(vq));
+ if (err)
+ goto err_state_extra;
+
virtqueue_vring_init_packed(&vring_packed, !!cfg_vq_val(cfg,
callbacks));
virtqueue_init(vq, tp_cfg->num);
@@ -2152,6 +2206,10 @@ static int virtqueue_resize_packed(struct virtqueue
*_vq, u32 num)
if (err)
goto err_state_extra;
+ err = vring_alloc_dma_packed(&vring_packed,
vring_need_unmap_buffer(vq));
+ if (err)
+ goto err_state_extra;
+
vring_free(&vq->vq);
virtqueue_vring_init_packed(&vring_packed, !!vq->vq.callback);
@@ -2662,6 +2720,12 @@ static struct virtqueue *__vring_new_virtqueue(struct
virtio_device *vdev,
return NULL;
}
+ err = vring_alloc_dma_split(vring_split, vring_need_unmap_buffer(vq));
+ if (err) {
+ kfree(vq);
+ return NULL;
+ }
+
virtqueue_vring_init_split(vring_split, vq);
virtqueue_init(vq, vring_split->vring.num);
@@ -2779,6 +2843,14 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq)
vq->premapped = true;
+ if (vq->packed_ring) {
+ kfree(vq->packed.desc_dma);
+ vq->packed.desc_dma = NULL;
+ } else {
+ kfree(vq->split.desc_dma);
+ vq->split.desc_dma = NULL;
+ }
+
END_USE(vq);
return 0;
@@ -2863,6 +2935,7 @@ static void vring_free(struct virtqueue *_vq)
kfree(vq->packed.desc_state);
kfree(vq->packed.desc_extra);
+ kfree(vq->packed.desc_dma);
} else {
vring_free_queue(vq->vq.vdev,
vq->split.queue_size_in_bytes,
@@ -2874,6 +2947,7 @@ static void vring_free(struct virtqueue *_vq)
if (!vq->packed_ring) {
kfree(vq->split.desc_state);
kfree(vq->split.desc_extra);
+ kfree(vq->split.desc_dma);
}
}
--
2.32.0.3.g01195cf9f
