[PATCH] Fix pci-dma compatibility code for "dev == NULL"

The compat API doesn't cope correctly if struct pci_dev is NULL, as it
can be for the x86 fake pci_dev handling.

include/asm-generic/pci-dma-compat.h

@@ -12,76 +12,76 @@
 static inline int
 pci_dma_supported(struct pci_dev *hwdev, u64 mask)
 {
-	return dma_supported(&hwdev->dev, mask);
+	return dma_supported(hwdev == NULL ? NULL : &hwdev->dev, mask);
 }
 
 static inline void *
 pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
 		     dma_addr_t *dma_handle)
 {
-	return dma_alloc_coherent(&hwdev->dev, size, dma_handle);
+	return dma_alloc_coherent(hwdev == NULL ? NULL : &hwdev->dev, size, dma_handle);
 }
 
 static inline void
 pci_free_consistent(struct pci_dev *hwdev, size_t size,
 		    void *vaddr, dma_addr_t dma_handle)
 {
-	dma_free_coherent(&hwdev->dev, size, vaddr, dma_handle);
+	dma_free_coherent(hwdev == NULL ? NULL : &hwdev->dev, size, vaddr, dma_handle);
 }
 
 static inline dma_addr_t
 pci_map_single(struct pci_dev *hwdev, void *ptr, size_t size, int direction)
 {
-	return dma_map_single(&hwdev->dev, ptr, size, (enum dma_data_direction)direction);
+	return dma_map_single(hwdev == NULL ? NULL : &hwdev->dev, ptr, size, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_unmap_single(struct pci_dev *hwdev, dma_addr_t dma_addr,
 		 size_t size, int direction)
 {
-	dma_unmap_single(&hwdev->dev, dma_addr, size, (enum dma_data_direction)direction);
+	dma_unmap_single(hwdev == NULL ? NULL : &hwdev->dev, dma_addr, size, (enum dma_data_direction)direction);
 }
 
 static inline dma_addr_t
 pci_map_page(struct pci_dev *hwdev, struct page *page,
 	     unsigned long offset, size_t size, int direction)
 {
-	return dma_map_page(&hwdev->dev, page, offset, size, (enum dma_data_direction)direction);
+	return dma_map_page(hwdev == NULL ? NULL : &hwdev->dev, page, offset, size, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_unmap_page(struct pci_dev *hwdev, dma_addr_t dma_address,
 	       size_t size, int direction)
 {
-	dma_unmap_page(&hwdev->dev, dma_address, size, (enum dma_data_direction)direction);
+	dma_unmap_page(hwdev == NULL ? NULL : &hwdev->dev, dma_address, size, (enum dma_data_direction)direction);
 }
 
 static inline int
 pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg,
 	   int nents, int direction)
 {
-	return dma_map_sg(&hwdev->dev, sg, nents, (enum dma_data_direction)direction);
+	return dma_map_sg(hwdev == NULL ? NULL : &hwdev->dev, sg, nents, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg,
 	     int nents, int direction)
 {
-	dma_unmap_sg(&hwdev->dev, sg, nents, (enum dma_data_direction)direction);
+	dma_unmap_sg(hwdev == NULL ? NULL : &hwdev->dev, sg, nents, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_dma_sync_single(struct pci_dev *hwdev, dma_addr_t dma_handle,
 		    size_t size, int direction)
 {
-	dma_sync_single(&hwdev->dev, dma_handle, size, (enum dma_data_direction)direction);
+	dma_sync_single(hwdev == NULL ? NULL : &hwdev->dev, dma_handle, size, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_dma_sync_sg(struct pci_dev *hwdev, struct scatterlist *sg,
 		int nelems, int direction)
 {
-	dma_sync_sg(&hwdev->dev, sg, nelems, (enum dma_data_direction)direction);
+	dma_sync_sg(hwdev == NULL ? NULL : &hwdev->dev, sg, nelems, (enum dma_data_direction)direction);
 }
 
 #endif