| Message ID | 1455655184-14478-7-git-send-email-niklas.soderlund+renesas@ragnatech.se (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Feb 16, 2016 at 09:39:42PM +0100, Niklas Söderlund wrote: > Enable slave transfers to devices behind IPMMU:s by mapping the slave IPMMU:s ? > addresses using the dma-mapping API. > > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > drivers/dma/sh/rcar-dmac.c | 52 +++++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 47 insertions(+), 5 deletions(-) > > diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c > index 743873c..6a24847 100644 > --- a/drivers/dma/sh/rcar-dmac.c > +++ b/drivers/dma/sh/rcar-dmac.c > @@ -1106,21 +1106,63 @@ 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) > +{ > + enum dma_data_direction dir; > + > + /* > + * We can't know the direction at this time, see documentation for > + * 'direction' in struct dma_slave_config. > + */ Okay so we are mapping on the device config, which doesn't seem intutive. Why is this not done during prepare calls? > + dir = DMA_BIDIRECTIONAL; > + > + if (slave->xfer_size) { > + dma_unmap_resource(chan->device->dev, slave->slave_addr, > + slave->xfer_size, dir, NULL); > + slave->slave_addr = 0; > + slave->xfer_size = 0; > + } > + > + if (size) { > + slave->slave_addr = dma_map_resource(chan->device->dev, addr, > + size, dir, NULL); > + > + 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); > + 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); > + return ret; > } > > static int rcar_dmac_chan_terminate_all(struct dma_chan *chan) > -- > 2.7.1 >
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 743873c..6a24847 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -1106,21 +1106,63 @@ 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) +{ + enum dma_data_direction dir; + + /* + * 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, NULL); + slave->slave_addr = 0; + slave->xfer_size = 0; + } + + if (size) { + slave->slave_addr = dma_map_resource(chan->device->dev, addr, + size, dir, NULL); + + 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); + 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); + return ret; } static int rcar_dmac_chan_terminate_all(struct dma_chan *chan)