mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-29 05:44:11 +00:00
Code Issues Releases Wiki Activity

dmaengine: Add support for per channel coherency handling

Browse source 
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>
This commit is contained in:
Peter Ujfalusi 2020-12-08 11:04:28 +02:00 committed by Vinod Koul
parent 4f910c035f
commit ab650ef6d5
1 changed files with 12 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
include/linux/dmaengine.h
View file

@ -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 */