dma-mapping: don't BUG when calling dma_map_resource on RAM

Use WARN_ON_ONCE to print a stack trace and return a proper error
code instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 9842085..b904d55 100644 (file)
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -353,7 +353,8 @@ static inline dma_addr_t dma_map_resource(struct device *dev,
        BUG_ON(!valid_dma_direction(dir));
 
        /* Don't allow RAM to be mapped */
-       BUG_ON(pfn_valid(PHYS_PFN(phys_addr)));
+       if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr))))
+               return DMA_MAPPING_ERROR;
 
        if (dma_is_direct(ops))
                addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs);