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. Thanks
