Hi Marek,
On 10/13/2015 07:22 PM, Marek Szyprowski wrote:
> Exynos GEM objects contains an array of pointers to the pages, which the
> allocated buffer consists of. Till now the code used some hacks (like
> relying on DMA-mapping internal structures or using ARM-specific
> dma_to_pfn helper) to build this array. This patch fixes this by adding
> proper call to dma_get_sgtable_attrs() and using the acquired scatter-list
> to construct needed array. This approach is more portable (work also for
> ARM64) and finally fixes the layering violation that was present in this
> code.
I also sent related patches to update codes of Exynos GEM object and i
think this can be applied easily on my patchset or i will be able to
rebase my patchset on your patch.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> ---
> Patch is based on exynos-drm-next branch.
> ---
> drivers/gpu/drm/exynos/exynos_drm_gem.c | 60
> +++++++++++++++++++--------------
> 1 file changed, 35 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c
> b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> index 29f48756e72f..e998a64a3dd0 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> @@ -25,6 +25,10 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem
> *exynos_gem)
> struct drm_device *dev = exynos_gem->base.dev;
> enum dma_attr attr;
> unsigned int nr_pages;
> + struct sg_table sgt;
> + struct scatterlist *s;
> + int ret = -ENOMEM;
> + int i, j;
>
> if (exynos_gem->dma_addr) {
> DRM_DEBUG_KMS("already allocated.\n");
> @@ -56,13 +60,10 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem
> *exynos_gem)
>
> nr_pages = exynos_gem->size >> PAGE_SHIFT;
>
> - if (!is_drm_iommu_supported(dev)) {
> - exynos_gem->pages = drm_calloc_large(nr_pages,
> - sizeof(struct page *));
> - if (!exynos_gem->pages) {
> - DRM_ERROR("failed to allocate pages.\n");
> - return -ENOMEM;
> - }
> + exynos_gem->pages = drm_calloc_large(nr_pages, sizeof(struct page *));
> + if (!exynos_gem->pages) {
> + DRM_ERROR("failed to allocate pages.\n");
> + return -ENOMEM;
> }
>
> exynos_gem->cookie = dma_alloc_attrs(dev->dev, exynos_gem->size,
> @@ -70,30 +71,40 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem
> *exynos_gem)
> &exynos_gem->dma_attrs);
> if (!exynos_gem->cookie) {
> DRM_ERROR("failed to allocate buffer.\n");
> - if (exynos_gem->pages)
> - drm_free_large(exynos_gem->pages);
> - return -ENOMEM;
> + goto err_free;
> }
>
> - if (exynos_gem->pages) {
> - dma_addr_t start_addr;
> - unsigned int i = 0;
> -
> - start_addr = exynos_gem->dma_addr;
> - while (i < nr_pages) {
> - exynos_gem->pages[i] =
> - pfn_to_page(dma_to_pfn(dev->dev, start_addr));
> - start_addr += PAGE_SIZE;
> - i++;
> - }
> - } else {
> - exynos_gem->pages = exynos_gem->cookie;
> + ret = dma_get_sgtable_attrs(dev->dev, &sgt, exynos_gem->cookie,
> + exynos_gem->dma_addr, exynos_gem->size,
> + &exynos_gem->dma_attrs);
> + if (ret < 0) {
> + DRM_ERROR("failed to get sgtable.\n");
> + goto err_dma_free;
> + }
> +
> + j = 0;
> + for_each_sg(sgt.sgl, s, sgt.orig_nents, i) {
> + int size = s->length >> PAGE_SHIFT;
> + struct page *page = sg_page(s);
> +
> + while (size-- > 0)
> + exynos_gem->pages[j++] = page++;
> }
drm_prime_sg_to_page_addr_arrays() will do same operation.
Thanks.
