[PATCH v5 10/38] drm: exynos: use common helper for a scatterlist contiguity check

From: Marek Szyprowski
Date: Wed May 13 2020 - 09:33:20 EST


Use common helper for checking the contiguity of the imported dma-buf.

Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
For more information, see '[PATCH v5 00/38] DRM: fix struct sg_table nents
vs. orig_nents misuse' thread:
https://lore.kernel.org/linux-iommu/20200513132114.6046-1-m.szyprowski@xxxxxxxxxxx/T/
---
drivers/gpu/drm/exynos/exynos_drm_gem.c | 23 +++--------------------
1 file changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 0df57ee..a49a8ea 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -431,27 +431,10 @@ struct drm_gem_object *
{
struct exynos_drm_gem *exynos_gem;

- if (sgt->nents < 1)
+ /* check if the entries in the sg_table are contiguous */
+ if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
+ DRM_ERROR("buffer chunks must be mapped contiguously");
return ERR_PTR(-EINVAL);
-
- /*
- * Check if the provided buffer has been mapped as contiguous
- * into DMA address space.
- */
- if (sgt->nents > 1) {
- dma_addr_t next_addr = sg_dma_address(sgt->sgl);
- struct scatterlist *s;
- unsigned int i;
-
- for_each_sg(sgt->sgl, s, sgt->nents, i) {
- if (!sg_dma_len(s))
- break;
- if (sg_dma_address(s) != next_addr) {
- DRM_ERROR("buffer chunks must be mapped contiguously");
- return ERR_PTR(-EINVAL);
- }
- next_addr = sg_dma_address(s) + sg_dma_len(s);
- }
}

exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
--
1.9.1