dmaengine: Move all map_sg/unmap_sg for slave channel to its client

Dan Williams wrote:
... DMA-slave clients request specific channels and know the hardware
details at a low level, so it should not be too high an expectation to
push dma mapping responsibility to the client.

Also this patch includes DMA_COMPL_{SRC,DEST}_UNMAP_SINGLE support for
dw_dmac driver.

Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 7b603e4b41db..5e10d3663ab5 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -576,6 +576,7 @@ atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
         struct scatterlist              *sg;
         unsigned int                    i;
         enum dma_data_direction         direction;
+        unsigned int                    sglen;
 
         /*
          * We don't do DMA on "complex" transfers, i.e. with
@@ -605,11 +606,14 @@ atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
         else
                 direction = DMA_TO_DEVICE;
 
+        sglen = dma_map_sg(&host->pdev->dev, data->sg, data->sg_len, direction);
+        if (sglen != data->sg_len)
+                goto unmap_exit;
         desc = chan->device->device_prep_slave_sg(chan,
                         data->sg, data->sg_len, direction,
                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
         if (!desc)
-                return -ENOMEM;
+                goto unmap_exit;
 
         host->dma.data_desc = desc;
         desc->callback = atmci_dma_complete;
@@ -620,6 +624,9 @@ atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
         chan->device->device_issue_pending(chan);
 
         return 0;
+unmap_exit:
+        dma_unmap_sg(&host->pdev->dev, data->sg, sglen, direction);
+        return -ENOMEM;
 }
 
 #else /* CONFIG_MMC_ATMELMCI_DMA */