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>

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index da4e8b7..0aeb578 100644 (file)
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -253,25 +253,28 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
        list_move(&desc->desc_node, &atchan->free_list);
 
        /* unmap dma addresses */
-       if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
-               if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
-                       dma_unmap_single(chan2parent(&atchan->chan_common),
-                                       desc->lli.daddr,
-                                       desc->len, DMA_FROM_DEVICE);
-               else
-                       dma_unmap_page(chan2parent(&atchan->chan_common),
-                                       desc->lli.daddr,
-                                       desc->len, DMA_FROM_DEVICE);
-       }
-       if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
-               if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
-                       dma_unmap_single(chan2parent(&atchan->chan_common),
-                                       desc->lli.saddr,
-                                       desc->len, DMA_TO_DEVICE);
-               else
-                       dma_unmap_page(chan2parent(&atchan->chan_common),
-                                       desc->lli.saddr,
-                                       desc->len, DMA_TO_DEVICE);
+       if (!atchan->chan_common.private) {
+               struct device *parent = chan2parent(&atchan->chan_common);
+               if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+                       if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
+                               dma_unmap_single(parent,
+                                               desc->lli.daddr,
+                                               desc->len, DMA_FROM_DEVICE);
+                       else
+                               dma_unmap_page(parent,
+                                               desc->lli.daddr,
+                                               desc->len, DMA_FROM_DEVICE);
+               }
+               if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+                       if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
+                               dma_unmap_single(parent,
+                                               desc->lli.saddr,
+                                               desc->len, DMA_TO_DEVICE);
+                       else
+                               dma_unmap_page(parent,
+                                               desc->lli.saddr,
+                                               desc->len, DMA_TO_DEVICE);
+               }
        }
 
        /*
@@ -647,8 +650,6 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
        reg_width = atslave->reg_width;
 
-       sg_len = dma_map_sg(chan2parent(chan), sgl, sg_len, direction);
-
        ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla;
        ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN;
 

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 514ef7d..8fb7482 100644 (file)
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -212,16 +212,25 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc)
        list_splice_init(&desc->tx_list, &dwc->free_list);
        list_move(&desc->desc_node, &dwc->free_list);
 
-       /*
-        * We use dma_unmap_page() regardless of how the buffers were
-        * mapped before they were submitted...
-        */
-       if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP))
-               dma_unmap_page(chan2parent(&dwc->chan), desc->lli.dar,
-                              desc->len, DMA_FROM_DEVICE);
-       if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP))
-               dma_unmap_page(chan2parent(&dwc->chan), desc->lli.sar,
-                              desc->len, DMA_TO_DEVICE);
+       if (!dwc->chan.private) {
+               struct device *parent = chan2parent(&dwc->chan);
+               if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+                       if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
+                               dma_unmap_single(parent, desc->lli.dar,
+                                               desc->len, DMA_FROM_DEVICE);
+                       else
+                               dma_unmap_page(parent, desc->lli.dar,
+                                               desc->len, DMA_FROM_DEVICE);
+               }
+               if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+                       if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
+                               dma_unmap_single(parent, desc->lli.sar,
+                                               desc->len, DMA_TO_DEVICE);
+                       else
+                               dma_unmap_page(parent, desc->lli.sar,
+                                               desc->len, DMA_TO_DEVICE);
+               }
+       }
 
        /*
         * The API requires that no submissions are done from a
@@ -658,8 +667,6 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
        reg_width = dws->reg_width;
        prev = first = NULL;
 
-       sg_len = dma_map_sg(chan2parent(chan), sgl, sg_len, direction);
-
        switch (direction) {
        case DMA_TO_DEVICE:
                ctllo = (DWC_DEFAULT_CTLLO

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 7b603e4..5e10d36 100644 (file)
--- 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 */