dma-direct: use is_swiotlb_active in dma_direct_map_page

Use the more specific is_swiotlb_active check instead of checking the
global swiotlb_force variable.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>
Tested-by: Boris Ostrovsky <[email protected]>

Author: Christoph Hellwig

kernel/dma/direct.h

@@ -91,7 +91,7 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
 		return swiotlb_map(dev, phys, size, dir, attrs);
 
 	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
-		if (swiotlb_force != SWIOTLB_NO_FORCE)
+		if (is_swiotlb_active(dev))
 			return swiotlb_map(dev, phys, size, dir, attrs);
 
 		dev_WARN_ONCE(dev, 1,