From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart 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> 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-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1455065878-11906-7-git-send-email-niklas.soderlund+renesas-1zkq55x86MTxsAP9Fp7wbw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Niklas =?ISO-8859-1?Q?S=F6derlund?= Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, geert+renesas-gXvu3+zWzMSzQB+pC5nmwQ@public.gmane.org, vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-renesas-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hi Niklas, Thank you for the patch. On Wednesday 10 February 2016 01:57:56 Niklas S=F6derlund wrote: > Enable slave transfers to devices behind IPMMU:s by mapping the slave > addresses using the dma-mapping API. > = > Signed-off-by: Niklas S=F6derlund > --- > 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 =3D 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 =3D 0; > + slave->xfer_size =3D 0; > + } > + > + if (size) { > + slave->slave_addr =3D 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 =3D 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 =3D size; > + } > + > + return 0; > +} > + > static int rcar_dmac_device_config(struct dma_chan *chan, > struct dma_slave_config *cfg) > { > struct rcar_dmac_chan *rchan =3D 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 =3D cfg->src_addr; > - rchan->dst.slave_addr =3D cfg->dst_addr; > - rchan->src.xfer_size =3D cfg->src_addr_width; > - rchan->dst.xfer_size =3D cfg->dst_addr_width; > = > - return 0; > + ret =3D rcar_dmac_set_slave_addr(chan, &rchan->src, cfg->src_addr, > + cfg->src_addr_width); > + if (ret) > + return ret; > + > + ret =3D 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