diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/tegra/gem.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c index 746dae32c484..6dfad56eee2b 100644 --- a/drivers/gpu/drm/tegra/gem.c +++ b/drivers/gpu/drm/tegra/gem.c @@ -27,6 +27,29 @@ static void tegra_bo_put(struct host1x_bo *bo) drm_gem_object_put_unlocked(&obj->gem); } +/* XXX move this into lib/scatterlist.c? */ +static int sg_alloc_table_from_sg(struct sg_table *sgt, struct scatterlist *sg, + unsigned int nents, gfp_t gfp_mask) +{ + struct scatterlist *dst; + unsigned int i; + int err; + + err = sg_alloc_table(sgt, nents, gfp_mask); + if (err < 0) + return err; + + dst = sgt->sgl; + + for (i = 0; i < nents; i++) { + sg_set_page(dst, sg_page(sg), sg->length, 0); + dst = sg_next(dst); + sg = sg_next(sg); + } + + return 0; +} + static struct sg_table *tegra_bo_pin(struct device *dev, struct host1x_bo *bo, dma_addr_t *phys) { @@ -52,11 +75,31 @@ static struct sg_table *tegra_bo_pin(struct device *dev, struct host1x_bo *bo, return ERR_PTR(-ENOMEM); if (obj->pages) { + /* + * If the buffer object was allocated from the explicit IOMMU + * API code paths, construct an SG table from the pages. + */ err = sg_alloc_table_from_pages(sgt, obj->pages, obj->num_pages, 0, obj->gem.size, GFP_KERNEL); if (err < 0) goto free; + } else if (obj->sgt) { + /* + * If the buffer object already has an SG table but no pages + * were allocated for it, it means the buffer was imported and + * the SG table needs to be copied to avoid overwriting any + * other potential users of the original SG table. + */ + err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl, obj->sgt->nents, + GFP_KERNEL); + if (err < 0) + goto free; } else { + /* + * If the buffer object had no pages allocated and if it was + * not imported, it had to be allocated with the DMA API, so + * the DMA API helper can be used. + */ err = dma_get_sgtable(dev, sgt, obj->vaddr, obj->iova, obj->gem.size); if (err < 0) |