From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752387AbdFPUka (ORCPT ); Fri, 16 Jun 2017 16:40:30 -0400 Received: from mail-qk0-f196.google.com ([209.85.220.196]:35488 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750879AbdFPUk0 (ORCPT ); Fri, 16 Jun 2017 16:40:26 -0400 MIME-Version: 1.0 In-Reply-To: <20170616181059.19206-4-hch@lst.de> References: <20170616181059.19206-1-hch@lst.de> <20170616181059.19206-4-hch@lst.de> From: Alexander Duyck Date: Fri, 16 Jun 2017 13:40:24 -0700 Message-ID: Subject: Re: [PATCH 03/44] dmaengine: ioat: don't use DMA_ERROR_CODE To: Christoph Hellwig Cc: "the arch/x86 maintainers" , 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, "open list:INTEL IOMMU (VT-d)" , Netdev , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 16, 2017 at 11:10 AM, Christoph Hellwig wrote: > DMA_ERROR_CODE is not a public API and will go away. Instead properly > unwind based on the loop counter. > > Signed-off-by: Christoph Hellwig > Acked-by: Dave Jiang > Acked-By: Vinod Koul > --- > drivers/dma/ioat/init.c | 24 +++++++----------------- > 1 file changed, 7 insertions(+), 17 deletions(-) > > diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c > index 6ad4384b3fa8..ed8ed1192775 100644 > --- a/drivers/dma/ioat/init.c > +++ b/drivers/dma/ioat/init.c > @@ -839,8 +839,6 @@ static int ioat_xor_val_self_test(struct ioatdma_device *ioat_dma) > goto free_resources; > } > > - for (i = 0; i < IOAT_NUM_SRC_TEST; i++) > - dma_srcs[i] = DMA_ERROR_CODE; > for (i = 0; i < IOAT_NUM_SRC_TEST; i++) { > dma_srcs[i] = dma_map_page(dev, xor_srcs[i], 0, PAGE_SIZE, > DMA_TO_DEVICE); > @@ -910,8 +908,6 @@ static int ioat_xor_val_self_test(struct ioatdma_device *ioat_dma) > > xor_val_result = 1; > > - for (i = 0; i < IOAT_NUM_SRC_TEST + 1; i++) > - dma_srcs[i] = DMA_ERROR_CODE; > for (i = 0; i < IOAT_NUM_SRC_TEST + 1; i++) { > dma_srcs[i] = dma_map_page(dev, xor_val_srcs[i], 0, PAGE_SIZE, > DMA_TO_DEVICE); > @@ -965,8 +961,6 @@ static int ioat_xor_val_self_test(struct ioatdma_device *ioat_dma) > op = IOAT_OP_XOR_VAL; > > xor_val_result = 0; > - for (i = 0; i < IOAT_NUM_SRC_TEST + 1; i++) > - dma_srcs[i] = DMA_ERROR_CODE; > for (i = 0; i < IOAT_NUM_SRC_TEST + 1; i++) { > dma_srcs[i] = dma_map_page(dev, xor_val_srcs[i], 0, PAGE_SIZE, > DMA_TO_DEVICE); > @@ -1017,18 +1011,14 @@ static int ioat_xor_val_self_test(struct ioatdma_device *ioat_dma) > goto free_resources; > dma_unmap: > if (op == IOAT_OP_XOR) { > - if (dest_dma != DMA_ERROR_CODE) > - dma_unmap_page(dev, dest_dma, PAGE_SIZE, > - DMA_FROM_DEVICE); > - for (i = 0; i < IOAT_NUM_SRC_TEST; i++) > - if (dma_srcs[i] != DMA_ERROR_CODE) > - dma_unmap_page(dev, dma_srcs[i], PAGE_SIZE, > - DMA_TO_DEVICE); > + while (--i >= 0) > + dma_unmap_page(dev, dma_srcs[i], PAGE_SIZE, > + DMA_TO_DEVICE); > + dma_unmap_page(dev, dest_dma, PAGE_SIZE, DMA_FROM_DEVICE); > } else if (op == IOAT_OP_XOR_VAL) { > - for (i = 0; i < IOAT_NUM_SRC_TEST + 1; i++) > - if (dma_srcs[i] != DMA_ERROR_CODE) > - dma_unmap_page(dev, dma_srcs[i], PAGE_SIZE, > - DMA_TO_DEVICE); > + while (--i >= 0) > + dma_unmap_page(dev, dma_srcs[i], PAGE_SIZE, > + DMA_TO_DEVICE); Wouldn't it make more sense to pull out the while loop and just call dma_unmap_page on dest_dma if "op == IOAT_OP_XOR"? Odds are it is what the compiler is already generating and will save a few lines of code so what you end up with is something like: while (--i >= 0) dma_unmap_page(dev, dma_srcs[i], PAGE_SIZE, DMA_TO_DEVICE); if (op == IOAT_OP_XOR) dma_unmap_page(dev, dest_dma, PAGE_SIZE, DMA_FROM_DEVICE); > } > free_resources: > dma->device_free_chan_resources(dma_chan); > -- > 2.11.0 >