[PATCH v2 2/2] spi: sh-msiof: Use correct device for DMA mapping with IOMMU

From: Geert Uytterhoeven
Date: Fri Jul 11 2014 - 11:56:48 EST


To function correctly in the presence of an IOMMU, the DMA buffers must be
mapped using the DMA channel's device instead of the MSIOF platform
device's device.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
v2:
- Use "dma_chan.device->dev" instead of "dma_chan.dev->device",
- Also fix calls to dma_unmap_single(), dma_mapping_error(), and
dma_sync_single_for_*()".
---
drivers/spi/spi-sh-msiof.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 9922ed3a4441..6f449b24704a 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -644,8 +644,8 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,

if (tx) {
ier_bits |= IER_TDREQE | IER_TDMAE;
- dma_sync_single_for_device(&p->pdev->dev, p->tx_dma_addr, len,
- DMA_TO_DEVICE);
+ dma_sync_single_for_device(p->master->dma_tx->device->dev,
+ p->tx_dma_addr, len, DMA_TO_DEVICE);
desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
p->tx_dma_addr, len, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
@@ -716,7 +716,8 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
}

if (rx)
- dma_sync_single_for_cpu(&p->pdev->dev, p->rx_dma_addr, len,
+ dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
+ p->rx_dma_addr, len,
DMA_FROM_DEVICE);

return 0;
@@ -996,6 +997,7 @@ static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
const struct resource *res;
struct spi_master *master;
+ struct device *tx_dev, *rx_dev;

if (!info || !info->dma_tx_id || !info->dma_rx_id)
return 0; /* The driver assumes no error */
@@ -1026,21 +1028,23 @@ static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
if (!p->rx_dma_page)
goto free_tx_page;

- p->tx_dma_addr = dma_map_single(dev, p->tx_dma_page, PAGE_SIZE,
+ tx_dev = master->dma_tx->device->dev;
+ p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
DMA_TO_DEVICE);
- if (dma_mapping_error(dev, p->tx_dma_addr))
+ if (dma_mapping_error(tx_dev, p->tx_dma_addr))
goto free_rx_page;

- p->rx_dma_addr = dma_map_single(dev, p->rx_dma_page, PAGE_SIZE,
+ rx_dev = master->dma_rx->device->dev;
+ p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
DMA_FROM_DEVICE);
- if (dma_mapping_error(dev, p->rx_dma_addr))
+ if (dma_mapping_error(rx_dev, p->rx_dma_addr))
goto unmap_tx_page;

dev_info(dev, "DMA available");
return 0;

unmap_tx_page:
- dma_unmap_single(dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
+ dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
free_rx_page:
free_page((unsigned long)p->rx_dma_page);
free_tx_page:
@@ -1062,8 +1066,10 @@ static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
return;

dev = &p->pdev->dev;
- dma_unmap_single(dev, p->rx_dma_addr, PAGE_SIZE, DMA_FROM_DEVICE);
- dma_unmap_single(dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
+ dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
+ PAGE_SIZE, DMA_FROM_DEVICE);
+ dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
+ PAGE_SIZE, DMA_TO_DEVICE);
free_page((unsigned long)p->rx_dma_page);
free_page((unsigned long)p->tx_dma_page);
dma_release_channel(master->dma_rx);
--
1.9.1

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