From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99551C4363A for ; Tue, 27 Oct 2020 00:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6200C2076A for ; Tue, 27 Oct 2020 00:43:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603759410; bh=3Fr6HPJQmQnlZLOd4j4lqZ0K3iwWPgAdGpAl9e9fpS8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zpTIY15tuRbLYOrZee+FtrvrRgQrPI9W/Fa6zHWD8pw1cgG/aUYZiGkaLj+0eoThs OP78oX/KuTGp/dN89vYvqNZlJ/ne7XgWA/oXfRcqnEc5xDe/sgKFvXzVfu70WfScWG ZMKSYCV7gzHWnDYQjS6Kq4NEf5b0nHQ3VBBJ/Nx8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2442418AbgJ0AnU (ORCPT ); Mon, 26 Oct 2020 20:43:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:49772 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409107AbgJZXuY (ORCPT ); Mon, 26 Oct 2020 19:50:24 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3DE6220874; Mon, 26 Oct 2020 23:50:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603756223; bh=3Fr6HPJQmQnlZLOd4j4lqZ0K3iwWPgAdGpAl9e9fpS8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uJyb7RrWaQGlM8i0f7g4PzhNhKQNOOY+dRXPym7wXywir+qbjOp10M4rsf8k/wCOB KGKvcHFzEqjtnaPJp0xOWdI+S6QT5oW5XHj+dS4narYPDCYWRUHjQNgyLD25ku4DbC On/icoH6flvEsOr1TA5wkpJBPOsxKy+W6qU4JNcU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Marek Szyprowski , Qiang Yu , Sasha Levin , dri-devel@lists.freedesktop.org, lima@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.9 063/147] drm: lima: fix common struct sg_table related issues Date: Mon, 26 Oct 2020 19:47:41 -0400 Message-Id: <20201026234905.1022767-63-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201026234905.1022767-1-sashal@kernel.org> References: <20201026234905.1022767-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marek Szyprowski [ Upstream commit c3d9c17f486d5c54940487dc31a54ebfdeeb371a ] 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: Qiang Yu Signed-off-by: Sasha Levin --- drivers/gpu/drm/lima/lima_gem.c | 11 ++++++++--- drivers/gpu/drm/lima/lima_vm.c | 5 ++--- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c index 155f2b4b4030a..11223fe348dfe 100644 --- a/drivers/gpu/drm/lima/lima_gem.c +++ b/drivers/gpu/drm/lima/lima_gem.c @@ -69,8 +69,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm) return ret; if (bo->base.sgt) { - dma_unmap_sg(dev, bo->base.sgt->sgl, - bo->base.sgt->nents, DMA_BIDIRECTIONAL); + dma_unmap_sgtable(dev, bo->base.sgt, DMA_BIDIRECTIONAL, 0); sg_free_table(bo->base.sgt); } else { bo->base.sgt = kmalloc(sizeof(*bo->base.sgt), GFP_KERNEL); @@ -80,7 +79,13 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm) } } - dma_map_sg(dev, sgt.sgl, sgt.nents, DMA_BIDIRECTIONAL); + ret = dma_map_sgtable(dev, &sgt, DMA_BIDIRECTIONAL, 0); + if (ret) { + sg_free_table(&sgt); + kfree(bo->base.sgt); + bo->base.sgt = NULL; + return ret; + } *bo->base.sgt = sgt; diff --git a/drivers/gpu/drm/lima/lima_vm.c b/drivers/gpu/drm/lima/lima_vm.c index 5b92fb82674a9..2b2739adc7f53 100644 --- a/drivers/gpu/drm/lima/lima_vm.c +++ b/drivers/gpu/drm/lima/lima_vm.c @@ -124,7 +124,7 @@ int lima_vm_bo_add(struct lima_vm *vm, struct lima_bo *bo, bool create) if (err) goto err_out1; - for_each_sg_dma_page(bo->base.sgt->sgl, &sg_iter, bo->base.sgt->nents, 0) { + for_each_sgtable_dma_page(bo->base.sgt, &sg_iter, 0) { err = lima_vm_map_page(vm, sg_page_iter_dma_address(&sg_iter), bo_va->node.start + offset); if (err) @@ -298,8 +298,7 @@ int lima_vm_map_bo(struct lima_vm *vm, struct lima_bo *bo, int pageoff) mutex_lock(&vm->lock); base = bo_va->node.start + (pageoff << PAGE_SHIFT); - for_each_sg_dma_page(bo->base.sgt->sgl, &sg_iter, - bo->base.sgt->nents, pageoff) { + for_each_sgtable_dma_page(bo->base.sgt, &sg_iter, pageoff) { err = lima_vm_map_page(vm, sg_page_iter_dma_address(&sg_iter), base + offset); if (err) -- 2.25.1