powerpc/dma: Add optional platform override of dma_set_mask()
Some platforms may want to override dma_set_mask() to take into
account some specific "features" such as the availability of
a direct-map window in addition to an iommu.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 84d6367..f368c075 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -12,6 +12,7 @@
#include <linux/memblock.h>
#include <asm/bug.h>
#include <asm/abs_addr.h>
+#include <asm/machdep.h>
/*
* Generic direct DMA implementation
@@ -154,6 +155,23 @@
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
+int dma_set_mask(struct device *dev, u64 dma_mask)
+{
+ struct dma_map_ops *dma_ops = get_dma_ops(dev);
+
+ if (ppc_md.dma_set_mask)
+ return ppc_md.dma_set_mask(dev, dma_mask);
+ if (unlikely(dma_ops == NULL))
+ return -EIO;
+ if (dma_ops->set_dma_mask != NULL)
+ return dma_ops->set_dma_mask(dev, dma_mask);
+ if (!dev->dma_mask || !dma_supported(dev, dma_mask))
+ return -EIO;
+ *dev->dma_mask = dma_mask;
+ return 0;
+}
+EXPORT_SYMBOL(dma_set_mask);
+
static int __init dma_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);