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authorPeter Ujfalusi <peter.ujfalusi@ti.com>2020-12-08 12:04:28 +0300
committerVinod Koul <vkoul@kernel.org>2020-12-11 18:50:08 +0300
commitab650ef6d548153862119e1bf3bf267510707f48 (patch)
tree9ec923ada712fb62c210df4e216bcb0369a7bada /include/linux/dmaengine.h
parent4f910c035f38053ac8eb63a672c78862c535cd0f (diff)
downloadlinux-ab650ef6d548153862119e1bf3bf267510707f48.tar.xz
dmaengine: Add support for per channel coherency handling
If the DMA device supports per channel coherency configuration (a channel can be configured to have coherent or not coherent view) then a single device (the DMA controller's device) can not be used for dma_api for all channels as channels can have different coherency. Introduce custom_dma_mapping flag for the dma_chan and a new helper to get the device pointer to be used for dma_api for the given channel. Client drivers should be updated to be able to support per channel coherency by: - dma_map_single(chan->device->dev, ptr, size, DMA_TO_DEVICE); + struct device *dma_dev = dmaengine_get_dma_device(chan); + + dma_map_single(dma_dev, ptr, size, DMA_TO_DEVICE); Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Link: https://lore.kernel.org/r/20201208090440.31792-9-peter.ujfalusi@ti.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'include/linux/dmaengine.h')
-rw-r--r--include/linux/dmaengine.h12
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index aed44888cad3..68130f5f599e 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -357,11 +357,14 @@ struct dma_chan {
* @chan: driver channel device
* @device: sysfs device
* @dev_id: parent dma_device dev_id
+ * @chan_dma_dev: The channel is using custom/different dma-mapping
+ * compared to the parent dma_device
*/
struct dma_chan_dev {
struct dma_chan *chan;
struct device device;
int dev_id;
+ bool chan_dma_dev;
};
/**
@@ -1618,4 +1621,13 @@ dmaengine_get_direction_text(enum dma_transfer_direction dir)
return "invalid";
}
}
+
+static inline struct device *dmaengine_get_dma_device(struct dma_chan *chan)
+{
+ if (chan->dev->chan_dma_dev)
+ return &chan->dev->device;
+
+ return chan->device->dev;
+}
+
#endif /* DMAENGINE_H */