diff options
| -rw-r--r-- | drivers/dma/sh/rcar-dmac.c | 82 |
1 files changed, 74 insertions, 8 deletions
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index cf983a9df3f1..22a5e406a589 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -128,6 +128,18 @@ struct rcar_dmac_chan_slave { }; /* + * struct rcar_dmac_chan_map - Map of slave device phys to dma address + * @addr: slave dma address + * @dir: direction of mapping + * @slave: slave configuration that is mapped + */ +struct rcar_dmac_chan_map { + dma_addr_t addr; + enum dma_data_direction dir; + struct rcar_dmac_chan_slave slave; +}; + +/* * struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel * @chan: base DMA channel object * @iomem: channel I/O memory base @@ -152,6 +164,7 @@ struct rcar_dmac_chan { struct rcar_dmac_chan_slave src; struct rcar_dmac_chan_slave dst; + struct rcar_dmac_chan_map map; int mid_rid; spinlock_t lock; @@ -1029,13 +1042,65 @@ rcar_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dma_dest, DMA_MEM_TO_MEM, flags, false); } +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; + } 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); + 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; +} + static struct dma_async_tx_descriptor * rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction dir, unsigned long flags, void *context) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); - dma_addr_t dev_addr; /* Someone calling slave DMA on a generic channel? */ if (rchan->mid_rid < 0 || !sg_len) { @@ -1045,9 +1110,10 @@ rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, return NULL; } - dev_addr = dir == DMA_DEV_TO_MEM - ? rchan->src.slave_addr : rchan->dst.slave_addr; - return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr, + if (rcar_dmac_map_slave_addr(chan, dir)) + return NULL; + + return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, dir, flags, false); } @@ -1061,7 +1127,6 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); struct dma_async_tx_descriptor *desc; struct scatterlist *sgl; - dma_addr_t dev_addr; unsigned int sg_len; unsigned int i; @@ -1073,6 +1138,9 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, return NULL; } + if (rcar_dmac_map_slave_addr(chan, dir)) + return NULL; + sg_len = buf_len / period_len; if (sg_len > RCAR_DMAC_MAX_SG_LEN) { dev_err(chan->device->dev, @@ -1100,9 +1168,7 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, sg_dma_len(&sgl[i]) = period_len; } - dev_addr = dir == DMA_DEV_TO_MEM - ? rchan->src.slave_addr : rchan->dst.slave_addr; - desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr, + desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, dir, flags, true); kfree(sgl); |