On Wed, 31 Jan 2024 17:12:29 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote: > On Tue, Jan 30, 2024 at 7:42 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote: > > > > As discussed: > > http://lore.kernel.org/all/CACGkMEug-=C+VQhkMYSgUKMC==04m7-uem_yC21bgGkKZh845w@xxxxxxxxxxxxxx > > > > 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 <xuanzhuo@xxxxxxxxxxxxxxxxx> > > --- > > drivers/virtio/virtio_ring.c | 89 ++++++++++++++++++++++++++++-------- > > 1 file changed, 70 insertions(+), 19 deletions(-) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index 831667a57429..5bea25167259 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; > > @@ -472,13 +477,14 @@ 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); > > > > @@ -535,8 +541,11 @@ 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); > > @@ -1072,16 +1081,26 @@ static void virtqueue_vring_attach_split(struct vring_virtqueue *vq, > > vq->free_head = 0; > > } > > > > -static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split) > > +static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split, > > + bool need_unmap) > > { > > struct vring_desc_state_split *state; > > struct vring_desc_extra *extra; > > + struct vring_desc_dma *dma; > > u32 num = vring_split->vring.num; > > > > state = kmalloc_array(num, sizeof(struct vring_desc_state_split), GFP_KERNEL); > > if (!state) > > goto err_state; > > > > + if (need_unmap) { > > + dma = kmalloc_array(num, sizeof(struct vring_desc_dma), GFP_KERNEL); > > + if (!dma) > > + goto err_dma; > > + } else { > > + dma = NULL; > > + } > > + > > extra = vring_alloc_desc_extra(num); > > if (!extra) > > goto err_extra; > > @@ -1090,9 +1109,12 @@ static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_spl > > > > vring_split->desc_state = state; > > vring_split->desc_extra = extra; > > + vring_split->desc_dma = dma; > > return 0; > > > > err_extra: > > + kfree(dma); > > +err_dma: > > kfree(state); > > err_state: > > return -ENOMEM; > > @@ -1108,6 +1130,7 @@ 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, > > @@ -1209,7 +1232,8 @@ static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) > > if (err) > > goto err; > > > > - err = vring_alloc_state_extra_split(&vring_split); > > + err = vring_alloc_state_extra_split(&vring_split, > > + vring_need_unmap_buffer(vq)); > > if (err) > > goto err_state_extra; > > > > @@ -1245,14 +1269,16 @@ 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; > > I don't think this can be compiled. I do not find any error. Could you say more? Thanks. > > Thanks >
