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Commit cc212550 authored by Eli Billauer's avatar Eli Billauer Committed by Greg Kroah-Hartman
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staging: xillybus: Open Firmware driver supporting coherent DMA 



If the "dma-coherent" property is present in the device tree, the driver will
not perform cache invalidations. This feature significantly improves data
throughput and reduces CPU load.

Signed-off-by: default avatarEli Billauer <eli.billauer@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 24b33c90

drivers/staging/xillybus/xillybus_of.c

+20 −1
Original line number Diff line number Diff line
@@ -54,6 +54,13 @@ static void xilly_dma_sync_single_for_device_of(struct xilly_endpoint *ep, 
	dma_sync_single_for_device(ep->dev, dma_handle, size, direction);

}



static void xilly_dma_sync_single_nop(struct xilly_endpoint *ep,

				      dma_addr_t dma_handle,

				      size_t size,

				      int direction)

{

}



static dma_addr_t xilly_map_single_of(struct xilly_cleanup *mem,

				      struct xilly_endpoint *ep,

				      void *ptr,
@@ -102,14 +109,26 @@ static struct xilly_endpoint_hardware of_hw = { 
	.unmap_single = xilly_unmap_single_of

};



static struct xilly_endpoint_hardware of_hw_coherent = {

	.owner = THIS_MODULE,

	.hw_sync_sgl_for_cpu = xilly_dma_sync_single_nop,

	.hw_sync_sgl_for_device = xilly_dma_sync_single_nop,

	.map_single = xilly_map_single_of,

	.unmap_single = xilly_unmap_single_of

};



static int xilly_drv_probe(struct platform_device *op)

{

	struct device *dev = &op->dev;

	struct xilly_endpoint *endpoint;

	int rc = 0;

	int irq;

	struct xilly_endpoint_hardware *ephw = &of_hw;



	if (of_property_read_bool(dev->of_node, "dma-coherent"))

		ephw = &of_hw_coherent;



	endpoint = xillybus_init_endpoint(NULL, dev, &of_hw);

	endpoint = xillybus_init_endpoint(NULL, dev, ephw);



	if (!endpoint)

		return -ENOMEM;