crypto: ccp - Base AXI DMA cache settings on device tree

The default cache operations for ARM64 were changed during 3.15.
To use coherent operations a "dma-coherent" device tree property
is required.  If that property is not present in the device tree
node then the non-coherent operations are assigned for the device.

Add support to the ccp driver to assign the AXI DMA cache settings
based on whether the "dma-coherent" property is present in the device
node.  If present, use settings that work with the caches.  If not
present, use settings that do not look at the caches.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/ccp-platform.c b/drivers/crypto/ccp/ccp-platform.c
index 65e58291c66..b0a2806908f 100644
--- a/drivers/crypto/ccp/ccp-platform.c
+++ b/drivers/crypto/ccp/ccp-platform.c
@@ -22,6 +22,7 @@
 #include <linux/spinlock.h>
 #include <linux/delay.h>
 #include <linux/ccp.h>
+#include <linux/of.h>
 
 #include "ccp-dev.h"
 
@@ -112,6 +113,11 @@ static int ccp_platform_probe(struct platform_device *pdev)
 	*(dev->dma_mask) = DMA_BIT_MASK(48);
 	dev->coherent_dma_mask = DMA_BIT_MASK(48);
 
+	if (of_property_read_bool(dev->of_node, "dma-coherent"))
+		ccp->axcache = CACHE_WB_NO_ALLOC;
+	else
+		ccp->axcache = CACHE_NONE;
+
 	dev_set_drvdata(dev, ccp);
 
 	ret = ccp_init(ccp);