From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754537AbdGJPzT (ORCPT ); Mon, 10 Jul 2017 11:55:19 -0400 Received: from foss.arm.com ([217.140.101.70]:37320 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754476AbdGJPzS (ORCPT ); Mon, 10 Jul 2017 11:55:18 -0400 Subject: Re: [PATCH] dpaa_eth: use correct device for DMA mapping API To: Arnd Bergmann , Madalin Bucur Cc: Christoph Hellwig , Marek Szyprowski , "David S . Miller" , netdev@vger.kernel.org, Geert Uytterhoeven , Camelia Groza , Claudiu Manoil , linux-kernel@vger.kernel.org References: <20170710151447.2814348-1-arnd@arndb.de> From: Robin Murphy Message-ID: <5cb9b2d7-1512-1bfc-9560-59e17dda40f4@arm.com> Date: Mon, 10 Jul 2017 16:55:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170710151447.2814348-1-arnd@arndb.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/17 16:14, Arnd Bergmann wrote: > Geert Uytterhoeven ran into a build error without CONFIG_HAS_DMA, > as a result of the driver calling set_dma_ops(). While we can > fix the build error in the dma-mapping implementation, there is > another problem in this driver: > > The configuration for the DMA is done by the platform code, > looking up information about the system from the device tree. > This copies the information only in an incomplete way, setting > the dma_map_ops and forcing a specific mask, but ignoring all > settings regarding IOMMU, coherence etc. > > A better way to avoid the problem is to only ever pass a device > into the dma_mapping implementation that has been setup by the > platform code. In this case, that is the parent device, so we > can get that pointer at probe time. Fortunately, we already have > a pointer in the device specific structure for that, so we only > need to modify that. > > Fixes: fb52728a9294 ("dpaa_eth: reuse the dma_ops provided by the FMan MAC device") > Signed-off-by: Arnd Bergmann Acked-by: Robin Murphy Assuming all the DPAA subcomponents have the same DMA capabilities (which to the best of my knowledge they probably do), this is a neater approach than what I started a while back in the context of cleaning up arch_setup_dma_ops() abuse. FWIW, that looked like this: ----->8----- diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c index e2ca107f9d94..8eef0db5db30 100644 --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c @@ -2539,10 +2539,9 @@ static int dpaa_eth_probe(struct platform_device *pdev) priv->buf_layout[TX].priv_data_size = DPAA_TX_PRIV_DATA_SIZE; /* Tx */ /* device used for DMA mapping */ - arch_setup_dma_ops(dev, 0, 0, NULL, false); - err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(40)); + err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(40)); if (err) { - dev_err(dev, "dma_coerce_mask_and_coherent() failed\n"); + dev_err(dev, "dma_set_mask_and_coherent() failed\n"); goto dev_mask_failed; } diff --git a/drivers/net/ethernet/freescale/fman/mac.c b/drivers/net/ethernet/freescale/fman/mac.c index 0b31f8502ada..c81efbfa99c2 100644 --- a/drivers/net/ethernet/freescale/fman/mac.c +++ b/drivers/net/ethernet/freescale/fman/mac.c @@ -627,6 +627,10 @@ static struct platform_device *dpaa_eth_add_device(int fman_id, if (ret) goto err; + ret = of_dma_configure(&pdev->dev, node); + if (ret) + goto err; + ret = platform_device_add(pdev); if (ret) goto err; -----8<----- We might possibly need to revisit this if and when the question of IOMMU support in the fsl-mc driver comes up (all this stuff is completely paged out of my head at the moment, so I'm not certain), but for now I don't see any reason no to go with your patch. Robin. > --- > Not tested, please see if this works before applying! > --- > drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 11 ++--------- > 1 file changed, 2 insertions(+), 9 deletions(-) > > diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > index 757b873735a5..f7b0b928cd53 100644 > --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > @@ -2646,14 +2646,6 @@ static int dpaa_eth_probe(struct platform_device *pdev) > priv->buf_layout[RX].priv_data_size = DPAA_RX_PRIV_DATA_SIZE; /* Rx */ > priv->buf_layout[TX].priv_data_size = DPAA_TX_PRIV_DATA_SIZE; /* Tx */ > > - /* device used for DMA mapping */ > - set_dma_ops(dev, get_dma_ops(&pdev->dev)); > - err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(40)); > - if (err) { > - dev_err(dev, "dma_coerce_mask_and_coherent() failed\n"); > - goto dev_mask_failed; > - } > - > /* bp init */ > for (i = 0; i < DPAA_BPS_NUM; i++) { > int err; > @@ -2665,7 +2657,8 @@ static int dpaa_eth_probe(struct platform_device *pdev) > dpaa_bps[i]->raw_size = bpool_buffer_raw_size(i, DPAA_BPS_NUM); > /* avoid runtime computations by keeping the usable size here */ > dpaa_bps[i]->size = dpaa_bp_size(dpaa_bps[i]->raw_size); > - dpaa_bps[i]->dev = dev; > + /* DMA operations are done on the platform-provided device */ > + dpaa_bps[i]->dev = dev->parent; > > err = dpaa_bp_alloc_pool(dpaa_bps[i]); > if (err < 0) { >