From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751928AbdFNJSJ (ORCPT ); Wed, 14 Jun 2017 05:18:09 -0400 Received: from ozlabs.org ([103.22.144.67]:38261 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751758AbdFNJRb (ORCPT ); Wed, 14 Jun 2017 05:17:31 -0400 From: Michael Ellerman To: Christoph Hellwig , x86@kernel.org, linux-arm-kernel@lists.infradead.org, xen-devel@lists.xenproject.org, linux-c6x-dev@linux-c6x.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@linux-mips.org, openrisc@lists.librecores.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, iommu@lists.linux-foundation.org, netdev@vger.kernel.org, Alistair Popple Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 21/44] powerpc: implement ->mapping_error In-Reply-To: <20170608132609.32662-22-hch@lst.de> References: <20170608132609.32662-1-hch@lst.de> <20170608132609.32662-22-hch@lst.de> User-Agent: Notmuch/0.21 (https://notmuchmail.org) Date: Wed, 14 Jun 2017 19:17:27 +1000 Message-ID: <87vanz2ajc.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig writes: > DMA_ERROR_CODE is going to go away, so don't rely on it. Instead > define a ->mapping_error method for all IOMMU based dma operation > instances. The direct ops don't ever return an error and don't > need a ->mapping_error method. > > Signed-off-by: Christoph Hellwig > --- > arch/powerpc/include/asm/dma-mapping.h | 4 ---- > arch/powerpc/include/asm/iommu.h | 4 ++++ > arch/powerpc/kernel/dma-iommu.c | 6 ++++++ > arch/powerpc/kernel/iommu.c | 28 ++++++++++++++-------------- > arch/powerpc/platforms/cell/iommu.c | 1 + > arch/powerpc/platforms/pseries/vio.c | 3 ++- > 6 files changed, 27 insertions(+), 19 deletions(-) I also see: arch/powerpc/kernel/dma.c:const struct dma_map_ops dma_direct_ops = { Which you mentioned can't fail. arch/powerpc/platforms/pseries/ibmebus.c:static const struct dma_map_ops ibmebus_dma_ops = { Which can't fail. And: arch/powerpc/platforms/powernv/npu-dma.c:static const struct dma_map_ops dma_npu_ops = { arch/powerpc/platforms/ps3/system-bus.c:static const struct dma_map_ops ps3_sb_dma_ops = { arch/powerpc/platforms/ps3/system-bus.c:static const struct dma_map_ops ps3_ioc0_dma_ops = { All of which look like they definitely can fail, but return 0 on error and don't implement ->mapping_error. So I guess I'm acking this and adding a TODO to fix up the NPU code at least, the ps3 code is probably better left alone these days. Acked-by: Michael Ellerman cheers