gpd_dma_to_virt
gpd_current = gpd_dma_to_virt(ring, cur_gpd_dma);
gpd_current = gpd_dma_to_virt(ring, cur_gpd_dma);
gpd_current = gpd_dma_to_virt(ring, cur_gpd_dma);
gpd_current = gpd_dma_to_virt(ring, cur_gpd_dma);