summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorThierry Reding <treding@nvidia.com>2014-12-16 16:35:26 +0100
committerThierry Reding <treding@nvidia.com>2014-12-17 14:27:37 +0100
commita04251fc94b58ec25476e57986dfec727b812c22 (patch)
treeb0f5e99c969ab2ce782030e918ac07e6ebf17ef9
parent6b59cc1c86e90cccf8fb0b4dee5fbc226bb82d3e (diff)
downloadlinux-stable-a04251fc94b58ec25476e57986dfec727b812c22.tar.gz
linux-stable-a04251fc94b58ec25476e57986dfec727b812c22.tar.bz2
linux-stable-a04251fc94b58ec25476e57986dfec727b812c22.zip
drm/tegra: gem: Flush buffer objects upon allocation
Buffers obtained via shmem may still have associated cachelines. If they aren't properly flushed they may cause framebuffer corruption if the cache gets flushed after the application has drawn to it. Signed-off-by: Thierry Reding <treding@nvidia.com>
-rw-r--r--drivers/gpu/drm/tegra/gem.c36
1 files changed, 32 insertions, 4 deletions
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index da32086cbeaf..c888bed4036f 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -219,19 +219,47 @@ static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo,
size_t size)
{
+ struct scatterlist *s;
+ struct sg_table *sgt;
+ unsigned int i;
+
bo->pages = drm_gem_get_pages(&bo->gem);
if (IS_ERR(bo->pages))
return PTR_ERR(bo->pages);
bo->num_pages = size >> PAGE_SHIFT;
- bo->sgt = drm_prime_pages_to_sg(bo->pages, bo->num_pages);
- if (IS_ERR(bo->sgt)) {
- drm_gem_put_pages(&bo->gem, bo->pages, false, false);
- return PTR_ERR(bo->sgt);
+ sgt = drm_prime_pages_to_sg(bo->pages, bo->num_pages);
+ if (IS_ERR(sgt))
+ goto put_pages;
+
+ /*
+ * Fake up the SG table so that dma_map_sg() can be used to flush the
+ * pages associated with it. Note that this relies on the fact that
+ * the DMA API doesn't hook into IOMMU on Tegra, therefore mapping is
+ * only cache maintenance.
+ *
+ * TODO: Replace this by drm_clflash_sg() once it can be implemented
+ * without relying on symbols that are not exported.
+ */
+ for_each_sg(sgt->sgl, s, sgt->nents, i)
+ sg_dma_address(s) = sg_phys(s);
+
+ if (dma_map_sg(drm->dev, sgt->sgl, sgt->nents, DMA_TO_DEVICE) == 0) {
+ sgt = ERR_PTR(-ENOMEM);
+ goto release_sgt;
}
+ bo->sgt = sgt;
+
return 0;
+
+release_sgt:
+ sg_free_table(sgt);
+ kfree(sgt);
+put_pages:
+ drm_gem_put_pages(&bo->gem, bo->pages, false, false);
+ return PTR_ERR(sgt);
}
static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo,