On Tue, Aug 18, 2026 at 11:14 PM Alexander Graf <[email protected]> wrote: > > virtqueue_map_need_sync(), virtqueue_map_sync_single_range_for_cpu() and > virtqueue_map_sync_single_range_for_device() are exported, but no driver > in the tree calls them. They are the only path into the sync members of > struct virtio_map_ops, so whoever implements that struct next has to > decide what those members do with no caller to learn it from. > > Remove the three functions, their prototypes and their exports, and the > DMA sync shims that the virtio userspace harness kept for them. With > this, virtio_ring no longer exports a way to sync a mapping. > > Suggested-by: Michael S. Tsirkin <[email protected]>
Acked-by: Eugenio Pérez <[email protected]> Thanks! > Assisted-by: Kiro:claude-opus-5 checkpatch > Signed-off-by: Alexander Graf <[email protected]> > --- > drivers/virtio/virtio_ring.c | 89 -------------------------------- > include/linux/virtio.h | 8 --- > tools/virtio/linux/dma-mapping.h | 7 --- > 3 files changed, 104 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index b438dc2ce1b8..ea8e774b6d8e 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -3890,94 +3890,5 @@ int virtqueue_map_mapping_error(const struct virtqueue > *_vq, dma_addr_t addr) > } > EXPORT_SYMBOL_GPL(virtqueue_map_mapping_error); > > -/** > - * virtqueue_map_need_sync - check a dma address needs sync > - * @_vq: the struct virtqueue we're talking about. > - * @addr: DMA address > - * > - * Check if the dma address mapped by the virtqueue_map_* APIs needs to be > - * synchronized > - * > - * return bool > - */ > -bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr) > -{ > - const struct vring_virtqueue *vq = to_vvq(_vq); > - struct virtio_device *vdev = _vq->vdev; > - > - if (!vq->use_map_api) > - return false; > - > - if (vdev->map) > - return vdev->map->need_sync(vq->map, addr); > - else > - return dma_need_sync(vring_dma_dev(vq), addr); > -} > -EXPORT_SYMBOL_GPL(virtqueue_map_need_sync); > - > -/** > - * virtqueue_map_sync_single_range_for_cpu - map sync for cpu > - * @_vq: the struct virtqueue we're talking about. > - * @addr: DMA address > - * @offset: DMA address offset > - * @size: buf size for sync > - * @dir: DMA direction > - * > - * Before calling this function, use virtqueue_map_need_sync() to confirm > that > - * the DMA address really needs to be synchronized > - * > - */ > -void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq, > - dma_addr_t addr, > - unsigned long offset, size_t > size, > - enum dma_data_direction dir) > -{ > - const struct vring_virtqueue *vq = to_vvq(_vq); > - struct virtio_device *vdev = _vq->vdev; > - > - if (!vq->use_map_api) > - return; > - > - if (vdev->map) > - vdev->map->sync_single_for_cpu(vq->map, > - addr + offset, size, dir); > - else > - dma_sync_single_range_for_cpu(vring_dma_dev(vq), > - addr, offset, size, dir); > -} > -EXPORT_SYMBOL_GPL(virtqueue_map_sync_single_range_for_cpu); > - > -/** > - * virtqueue_map_sync_single_range_for_device - map sync for device > - * @_vq: the struct virtqueue we're talking about. > - * @addr: DMA address > - * @offset: DMA address offset > - * @size: buf size for sync > - * @dir: DMA direction > - * > - * Before calling this function, use virtqueue_map_need_sync() to confirm > that > - * the DMA address really needs to be synchronized > - */ > -void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq, > - dma_addr_t addr, > - unsigned long offset, size_t > size, > - enum dma_data_direction dir) > -{ > - const struct vring_virtqueue *vq = to_vvq(_vq); > - struct virtio_device *vdev = _vq->vdev; > - > - if (!vq->use_map_api) > - return; > - > - if (vdev->map) > - vdev->map->sync_single_for_device(vq->map, > - addr + offset, > - size, dir); > - else > - dma_sync_single_range_for_device(vring_dma_dev(vq), addr, > - offset, size, dir); > -} > -EXPORT_SYMBOL_GPL(virtqueue_map_sync_single_range_for_device); > - > MODULE_DESCRIPTION("Virtio ring implementation"); > MODULE_LICENSE("GPL"); > diff --git a/include/linux/virtio.h b/include/linux/virtio.h > index 93e573c56563..3122fc52a7c3 100644 > --- a/include/linux/virtio.h > +++ b/include/linux/virtio.h > @@ -312,14 +312,6 @@ void virtqueue_unmap_single_attrs(const struct virtqueue > *_vq, dma_addr_t addr, > unsigned long attrs); > int virtqueue_map_mapping_error(const struct virtqueue *_vq, dma_addr_t > addr); > > -bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr); > -void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq, > dma_addr_t addr, > - unsigned long offset, size_t > size, > - enum dma_data_direction dir); > -void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq, > dma_addr_t addr, > - unsigned long offset, size_t > size, > - enum dma_data_direction dir); > - > #ifdef CONFIG_VIRTIO_DEBUG > void virtio_debug_device_init(struct virtio_device *dev); > void virtio_debug_device_exit(struct virtio_device *dev); > diff --git a/tools/virtio/linux/dma-mapping.h > b/tools/virtio/linux/dma-mapping.h > index b9fc5e8338e3..eae160ce7142 100644 > --- a/tools/virtio/linux/dma-mapping.h > +++ b/tools/virtio/linux/dma-mapping.h > @@ -36,16 +36,9 @@ enum dma_data_direction { > > #define sg_dma_address(sg) (0) > #define sg_dma_len(sg) (0) > -#define dma_need_sync(v, a) (0) > #define dma_unmap_single_attrs(d, a, s, r, t) do { \ > (void)(d); (void)(a); (void)(s); (void)(r); (void)(t); \ > } while (0) > -#define dma_sync_single_range_for_cpu(d, a, o, s, r) do { \ > - (void)(d); (void)(a); (void)(o); (void)(s); (void)(r); \ > -} while (0) > -#define dma_sync_single_range_for_device(d, a, o, s, r) do { \ > - (void)(d); (void)(a); (void)(o); (void)(s); (void)(r); \ > -} while (0) > #define dma_max_mapping_size(...) SIZE_MAX > > /* >
