From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f45.google.com ([209.85.215.45]:36324 "EHLO mail-lf0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758172AbdAIPmd (ORCPT ); Mon, 9 Jan 2017 10:42:33 -0500 Received: by mail-lf0-f45.google.com with SMTP id o140so42034857lff.3 for ; Mon, 09 Jan 2017 07:42:27 -0800 (PST) From: "Niklas =?iso-8859-1?Q?S=F6derlund?=" Date: Mon, 9 Jan 2017 16:42:20 +0100 To: Laurent Pinchart Cc: linux-renesas-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org, iommu@lists.linux-foundation.org, linux@armlinux.org.uk, hch@infradead.org, dan.j.williams@intel.com, vinod.koul@intel.com, robin.murphy@arm.com, linus.walleij@linaro.org, arnd@arndb.de Subject: Re: [PATCHv9 6/6] dmaengine: rcar-dmac: add iommu support for slave transfers Message-ID: <20170109154220.GH29854@bigcity.dyn.berto.se> References: <20160810112219.17964-1-niklas.soderlund+renesas@ragnatech.se> <20160810112219.17964-7-niklas.soderlund+renesas@ragnatech.se> <6358234.jyTvyVnNF0@avalon> <26490346.qhNpbOL6eO@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <26490346.qhNpbOL6eO@avalon> Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: Hi Laurent, On 2017-01-02 01:08:04 +0200, Laurent Pinchart wrote: > Hi Niklas, > > On Monday 05 Sep 2016 12:52:44 Laurent Pinchart wrote: > > On Wednesday 10 Aug 2016 13:22:19 Niklas S�derlund wrote: > > > Enable slave transfers to a device behind a IPMMU by mapping the slave > > > addresses using the dma-mapping API. > > > > > > Signed-off-by: Niklas S�derlund > > > --- > > > drivers/dma/sh/rcar-dmac.c | 82 ++++++++++++++++++++++++++++++++++++----- > > > 1 file changed, 74 insertions(+), 8 deletions(-) > > > > > > diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c > > > index cf983a9..22a5e40 100644 > > > --- a/drivers/dma/sh/rcar-dmac.c > > > +++ b/drivers/dma/sh/rcar-dmac.c > > [snip] > > > > +static int rcar_dmac_map_slave_addr(struct dma_chan *chan, > > > + enum dma_transfer_direction dir) > > > +{ > > > + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); > > > + struct rcar_dmac_chan_map *map = &rchan->map; > > > + phys_addr_t dev_addr; > > > + size_t dev_size; > > > + enum dma_data_direction dev_dir; > > > + > > > + if (dir == DMA_DEV_TO_MEM) { > > > + dev_addr = rchan->src.slave_addr; > > > + dev_size = rchan->src.xfer_size; > > > + dev_dir = DMA_TO_DEVICE; > > > > Shouldn't this be DMA_FROM_DEVICE, and DMA_TO_DEVICE below ? > > This comment can be ignored (thank you Robin for the explanation), but ... > > > > + } else { > > > + dev_addr = rchan->dst.slave_addr; > > > + dev_size = rchan->dst.xfer_size; > > > + dev_dir = DMA_FROM_DEVICE; > > > + } > > > + > > > + /* Reuse current map if possible. */ > > > + if (dev_addr == map->slave.slave_addr && > > > + dev_size == map->slave.xfer_size && > > > + dev_dir == map->dir) > > > + return 0; > > > + > > > + /* Remove old mapping if present. */ > > > + if (map->slave.xfer_size) > > > + dma_unmap_resource(chan->device->dev, map->addr, > > > + map->slave.xfer_size, map->dir, 0); > > > > Unless I'm mistaken the resource will not be unmapped when freeing channel > > resources, will it ? > > I believe this one still needs to be addressed. I believe you are correct, I will look in to it and hopefully submit a patch to address it. Thanks for brining it up. > > > > + map->slave.xfer_size = 0; > > > + > > > + /* Create new slave address map. */ > > > + map->addr = dma_map_resource(chan->device->dev, dev_addr, dev_size, > > > + dev_dir, 0); > > > + > > > + if (dma_mapping_error(chan->device->dev, map->addr)) { > > > + dev_err(chan->device->dev, > > > + "chan%u: failed to map %zx@%pap", rchan->index, > > > + dev_size, &dev_addr); > > > + return -EIO; > > > + } > > > + > > > + dev_dbg(chan->device->dev, "chan%u: map %zx@%pap to %pad dir: %s\n", > > > + rchan->index, dev_size, &dev_addr, &map->addr, > > > > > + dev_dir == DMA_TO_DEVICE ? "DMA_TO_DEVICE" : > > "DMA_FROM_DEVICE"); > > > > > + > > > + map->slave.slave_addr = dev_addr; > > > + map->slave.xfer_size = dev_size; > > > + map->dir = dev_dir; > > > + > > > + return 0; > > > +} > > [snip] > > -- > Regards, > > Laurent Pinchart > -- Regards, Niklas S�derlund