bottom_sg 224 drivers/iommu/virtio-iommu.c struct scatterlist top_sg, bottom_sg; bottom_sg 225 drivers/iommu/virtio-iommu.c struct scatterlist *sg[2] = { &top_sg, &bottom_sg }; bottom_sg 246 drivers/iommu/virtio-iommu.c sg_init_one(&bottom_sg, req->buf + write_offset, len - write_offset);