20. 4. 22. 오후 8:40에 Marek Szyprowski 이(가) 쓴 글: > 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.
Picked it up. Thanks, Inki Dae > > Signed-off-by: Marek Szyprowski <[email protected]> > --- > v2: > - reworked a check for sgt->nents > - added a comment about a scatter-list contiguity check > - removed additional 'return ERR_PTR(-EINVAL)' accidentaly left after > debugging > --- > drivers/gpu/drm/exynos/exynos_drm_gem.c | 42 > ++++++++++++++++++++++++--------- > 1 file changed, 31 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c > b/drivers/gpu/drm/exynos/exynos_drm_gem.c > index 40514d3..f136efb 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c > @@ -458,6 +458,29 @@ struct drm_gem_object * > 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 @@ struct drm_gem_object * > > 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; > > _______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
