add mappable bit in DMA segment (#215)

remove duplicate code for initializing DMA segment,  mark DMA segment whether it's mappable, plus basic unit test for dma_addr_to_sg

Signed-off-by: Thanos Makatos <thanos.makatos@nutanix.com>

1 files changed, 1 insertions, 7 deletions

diff --git a/lib/dma.c b/lib/dma.c
index 0bb623c..69b3fe5 100644
--- a/lib/dma.c
+++ b/lib/dma.c
@@ -375,13 +375,7 @@ _dma_addr_sg_split(const dma_controller_t *dma,
                 size_t region_len = MIN(region_end - dma_addr, len);
 
                 if (cnt < max_sg) {
-                    sg[cnt].dma_addr = region->dma_addr;
-                    sg[cnt].region = idx;
-                    sg[cnt].offset = dma_addr - region->dma_addr;
-                    sg[cnt].length = region_len;
-                    if (_dma_should_mark_dirty(dma, prot)) {
-                        _dma_mark_dirty(dma, region, sg);
-                    }
+                    dma_init_sg(dma, sg, dma_addr, region_len, prot, idx);
                 }
 
                 cnt++;