From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752491AbcBKAdp (ORCPT ); Wed, 10 Feb 2016 19:33:45 -0500 Received: from galahad.ideasonboard.com ([185.26.127.97]:51460 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339AbcBKAdH convert rfc822-to-8bit (ORCPT ); Wed, 10 Feb 2016 19:33:07 -0500 From: Laurent Pinchart To: Niklas =?ISO-8859-1?Q?S=F6derlund?= Cc: linux-renesas-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, iommu@lists.linux-foundation.org, robin.murphy@arm.com, vinod.koul@intel.com, geert+renesas@glider.be, linus.walleij@linaro.org, dan.j.williams@intel.com, arnd@arndb.de, linux-arch@vger.kernel.org Subject: Re: [PATCH v3 6/8] dmaengine: rcar-dmac: add iommu support for slave transfers Date: Thu, 11 Feb 2016 02:33:30 +0200 Message-ID: <7836168.xWoq7RJUyE@avalon> User-Agent: KMail/4.14.8 (Linux/4.1.15-gentoo-r1; KDE/4.14.8; x86_64; ; ) In-Reply-To: <1455065878-11906-7-git-send-email-niklas.soderlund+renesas@ragnatech.se> References: <1455065878-11906-1-git-send-email-niklas.soderlund+renesas@ragnatech.se> <1455065878-11906-7-git-send-email-niklas.soderlund+renesas@ragnatech.se> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Niklas, Thank you for the patch. On Wednesday 10 February 2016 01:57:56 Niklas Söderlund wrote: > Enable slave transfers to devices behind IPMMU:s by mapping the slave > addresses using the dma-mapping API. > > Signed-off-by: Niklas Söderlund > --- > drivers/dma/sh/rcar-dmac.c | 57 +++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 52 insertions(+), 5 deletions(-) > > diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c > index 743873c..268407c 100644 > --- a/drivers/dma/sh/rcar-dmac.c > +++ b/drivers/dma/sh/rcar-dmac.c > @@ -1106,21 +1106,68 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, > dma_addr_t buf_addr, return desc; > } > > +static int rcar_dmac_set_slave_addr(struct dma_chan *chan, > + struct rcar_dmac_chan_slave *slave, > + phys_addr_t addr, size_t size) > +{ > + struct dma_attrs attrs; > + enum dma_data_direction dir; > + > + init_dma_attrs(&attrs); > + dma_set_attr(DMA_ATTR_NO_KERNEL_MAPPING, &attrs); > + dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs); > + > + /* > + * We can't know the direction at this time, see documentation for > + * 'direction' in struct dma_slave_config. > + */ > + dir = DMA_BIDIRECTIONAL; > + > + if (slave->xfer_size) { > + dma_unmap_resource(chan->device->dev, slave->slave_addr, > + slave->xfer_size, dir, &attrs); Nitpicking, you can align slave with chan on the previous line. > + slave->slave_addr = 0; > + slave->xfer_size = 0; > + } > + > + if (size) { > + slave->slave_addr = dma_map_resource(chan->device->dev, addr, > + size, dir, &attrs); > + > + if (dma_mapping_error(chan->device->dev, slave->slave_addr)) { > + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); > + > + dev_err(chan->device->dev, > + "chan%u: failed to map %zx@%pap", > + rchan->index, size, &addr); Indentation looks weird to me. > + return -EIO; > + } > + > + slave->xfer_size = size; > + } > + > + return 0; > +} > + > static int rcar_dmac_device_config(struct dma_chan *chan, > struct dma_slave_config *cfg) > { > struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); > + int ret; > > /* > * We could lock this, but you shouldn't be configuring the > * channel, while using it... > */ > - rchan->src.slave_addr = cfg->src_addr; > - rchan->dst.slave_addr = cfg->dst_addr; > - rchan->src.xfer_size = cfg->src_addr_width; > - rchan->dst.xfer_size = cfg->dst_addr_width; > > - return 0; > + ret = rcar_dmac_set_slave_addr(chan, &rchan->src, cfg->src_addr, > + cfg->src_addr_width); > + if (ret) > + return ret; > + > + ret = rcar_dmac_set_slave_addr(chan, &rchan->dst, cfg->dst_addr, > + cfg->dst_addr_width); You could align cfg with chan on the previous line (twice). With this fixed and the attributes removed as explained by Robin, Reviewed-by: Laurent Pinchart > + return ret; > } > > static int rcar_dmac_chan_terminate_all(struct dma_chan *chan) -- Regards, Laurent Pinchart