From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4D5B92584 for ; Thu, 23 Feb 2023 13:10:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8853C433EF; Thu, 23 Feb 2023 13:10:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1677157839; bh=47HkybMTWGbrHjBWDzB0ADfym3Hk7+pHNCBXA7tawxM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YDjkujNkbAFfMMwol0bbXDx3FGjazwPZ981tv52nNusqux18eJHxqlcP6sp1vaVdT fofHlfRDeKZGjEwRFQm77wf70PyzCRVKDXqdYG9ZpjDnxKhyyTAV23xyP55pdelNNY eYC83WgKxVUV5cyPVLrZ1zaZhCYz8kxcILUAuS68= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marek Szyprowski , Robin Murphy , Lucas Stach , Sasha Levin Subject: [PATCH 5.4 03/18] drm: etnaviv: fix common struct sg_table related issues Date: Thu, 23 Feb 2023 14:06:48 +0100 Message-Id: <20230223130425.829224326@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230223130425.680784802@linuxfoundation.org> References: <20230223130425.680784802@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Marek Szyprowski [ Upstream commit 182354a526a0540c9197e03d9fce8a949ffd36ca ] The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function returns the number of the created entries in the DMA address space. However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with the original number of the entries passed to the dma_map_sg(). struct sg_table is a common structure used for describing a non-contiguous memory buffer, used commonly in the DRM and graphics subsystems. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg() function. To avoid such issues, lets use a common dma-mapping wrappers operating directly on the struct sg_table objects and use scatterlist page iterators where possible. This, almost always, hides references to the nents and orig_nents entries, making the code robust, easier to follow and copy/paste safe. Signed-off-by: Marek Szyprowski Reviewed-by: Robin Murphy Acked-by: Lucas Stach Stable-dep-of: d37c120b7312 ("drm/etnaviv: don't truncate physical page address") Signed-off-by: Sasha Levin --- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 12 +++++------- drivers/gpu/drm/etnaviv/etnaviv_mmu.c | 15 ++++----------- 2 files changed, 9 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index 519948637186e..5107a0f5bc7fe 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c @@ -27,7 +27,7 @@ static void etnaviv_gem_scatter_map(struct etnaviv_gem_object *etnaviv_obj) * because display controller, GPU, etc. are not coherent. */ if (etnaviv_obj->flags & ETNA_BO_CACHE_MASK) - dma_map_sg(dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL); + dma_map_sgtable(dev->dev, sgt, DMA_BIDIRECTIONAL, 0); } static void etnaviv_gem_scatterlist_unmap(struct etnaviv_gem_object *etnaviv_obj) @@ -51,7 +51,7 @@ static void etnaviv_gem_scatterlist_unmap(struct etnaviv_gem_object *etnaviv_obj * discard those writes. */ if (etnaviv_obj->flags & ETNA_BO_CACHE_MASK) - dma_unmap_sg(dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL); + dma_unmap_sgtable(dev->dev, sgt, DMA_BIDIRECTIONAL, 0); } /* called with etnaviv_obj->lock held */ @@ -403,9 +403,8 @@ int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op, } if (etnaviv_obj->flags & ETNA_BO_CACHED) { - dma_sync_sg_for_cpu(dev->dev, etnaviv_obj->sgt->sgl, - etnaviv_obj->sgt->nents, - etnaviv_op_to_dma_dir(op)); + dma_sync_sgtable_for_cpu(dev->dev, etnaviv_obj->sgt, + etnaviv_op_to_dma_dir(op)); etnaviv_obj->last_cpu_prep_op = op; } @@ -420,8 +419,7 @@ int etnaviv_gem_cpu_fini(struct drm_gem_object *obj) if (etnaviv_obj->flags & ETNA_BO_CACHED) { /* fini without a prep is almost certainly a userspace error */ WARN_ON(etnaviv_obj->last_cpu_prep_op == 0); - dma_sync_sg_for_device(dev->dev, etnaviv_obj->sgt->sgl, - etnaviv_obj->sgt->nents, + dma_sync_sgtable_for_device(dev->dev, etnaviv_obj->sgt, etnaviv_op_to_dma_dir(etnaviv_obj->last_cpu_prep_op)); etnaviv_obj->last_cpu_prep_op = 0; } diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c index 790cbb20aaeba..9ba2fe48228f1 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c @@ -73,13 +73,13 @@ static int etnaviv_iommu_map(struct etnaviv_iommu_context *context, u32 iova, struct sg_table *sgt, unsigned len, int prot) { struct scatterlist *sg; unsigned int da = iova; - unsigned int i, j; + unsigned int i; int ret; if (!context || !sgt) return -EINVAL; - for_each_sg(sgt->sgl, sg, sgt->nents, i) { + for_each_sgtable_dma_sg(sgt, sg, i) { u32 pa = sg_dma_address(sg) - sg->offset; size_t bytes = sg_dma_len(sg) + sg->offset; @@ -95,14 +95,7 @@ static int etnaviv_iommu_map(struct etnaviv_iommu_context *context, u32 iova, return 0; fail: - da = iova; - - for_each_sg(sgt->sgl, sg, i, j) { - size_t bytes = sg_dma_len(sg) + sg->offset; - - etnaviv_context_unmap(context, da, bytes); - da += bytes; - } + etnaviv_context_unmap(context, iova, da - iova); return ret; } @@ -113,7 +106,7 @@ static void etnaviv_iommu_unmap(struct etnaviv_iommu_context *context, u32 iova, unsigned int da = iova; int i; - for_each_sg(sgt->sgl, sg, sgt->nents, i) { + for_each_sgtable_dma_sg(sgt, sg, i) { size_t bytes = sg_dma_len(sg) + sg->offset; etnaviv_context_unmap(context, da, bytes); -- 2.39.0