From 24f6fe796a964f1cba75030dbea297d7fb2f30cb Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Wed, 22 Apr 2020 13:40:59 +0200 Subject: drm/exynos: gem: rework scatter-list contiguity check on prime import Explicitly check if the imported buffer has been mapped as contiguous in the DMA address space, what is required by all Exynos DRM CRTC drivers. While touching this, set buffer flags depending on the availability of the IOMMU. Signed-off-by: Marek Szyprowski Signed-off-by: Inki Dae --- drivers/gpu/drm/exynos/exynos_drm_gem.c | 42 ++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 11 deletions(-) (limited to 'drivers/gpu/drm/exynos') diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c index 40514d3dcf60..f136efb9d1ff 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c @@ -458,6 +458,29 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev, int npages; int ret; + if (sgt->nents < 1) + 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); if (IS_ERR(exynos_gem)) { ret = PTR_ERR(exynos_gem); @@ -480,18 +503,15 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev, exynos_gem->sgt = sgt; - if (sgt->nents == 1) { - /* always physically continuous memory if sgt->nents is 1. */ - exynos_gem->flags |= EXYNOS_BO_CONTIG; - } else { - /* - * this case could be CONTIG or NONCONTIG type but for now - * sets NONCONTIG. - * TODO. we have to find a way that exporter can notify - * the type of its own buffer to importer. - */ + /* + * Buffer has been mapped as contiguous into DMA address space, + * but if there is IOMMU, it can be either CONTIG or NONCONTIG. + * We assume a simplified logic below: + */ + if (is_drm_iommu_supported(dev)) exynos_gem->flags |= EXYNOS_BO_NONCONTIG; - } + else + exynos_gem->flags |= EXYNOS_BO_CONTIG; return &exynos_gem->base; -- cgit v1.2.3