@@ -61,7 +61,7 @@ static int lowlevel_buffer_allocate(struct drm_device *dev,
unsigned int flags, struct exynos_drm_gem_buf *buf)
{
int ret = 0;
- enum dma_attr attr = DMA_ATTR_FORCE_CONTIGUOUS;
+ enum dma_attr attr;
unsigned int nr_pages;
DRM_DEBUG_KMS("%s\n", __FILE__);
@@ -73,8 +73,24 @@ static int lowlevel_buffer_allocate(struct drm_device *dev,
init_dma_attrs(&buf->dma_attrs);
- if (flags & EXYNOS_BO_NONCONTIG)
+ /*
+ * if EXYNOS_BO_CONTIG, fully physically contiguous memory
+ * region will be allocated else physically contiguous
+ * as possible.
+ */
+ if (flags & EXYNOS_BO_CONTIG) {
+ attr = DMA_ATTR_FORCE_CONTIGUOUS;
+ dma_set_attr(attr, &buf->dma_attrs);
+ }
+
+ /*
+ * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
+ * else cachable mapping.
+ */
+ if (flags & EXYNOS_BO_WC || !(flags & EXYNOS_BO_CACHABLE))
attr = DMA_ATTR_WRITE_COMBINE;
+ else
+ attr = DMA_ATTR_NON_CONSISTENT;
dma_set_attr(attr, &buf->dma_attrs);
dma_set_attr(DMA_ATTR_NO_KERNEL_MAPPING, &buf->dma_attrs);