PCI: Remove NULL device handling from PCI DMA API

Historically some ISA drivers used the old PCI DMA API with a NULL pdev
argument, but these days this isn't used and not too useful due to the
per-device DMA ops, so remove it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

include/linux/pci-dma-compat.h

@@ -17,91 +17,90 @@ static inline void *
 pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
 		     dma_addr_t *dma_handle)
 {
-	return dma_alloc_coherent(hwdev == NULL ? NULL : &hwdev->dev, size, dma_handle, GFP_ATOMIC);
+	return dma_alloc_coherent(&hwdev->dev, size, dma_handle, GFP_ATOMIC);
 }
 
 static inline void *
 pci_zalloc_consistent(struct pci_dev *hwdev, size_t size,
 		      dma_addr_t *dma_handle)
 {
-	return dma_zalloc_coherent(hwdev == NULL ? NULL : &hwdev->dev,
-				   size, dma_handle, GFP_ATOMIC);
+	return dma_zalloc_coherent(&hwdev->dev, size, dma_handle, GFP_ATOMIC);
 }
 
 static inline void
 pci_free_consistent(struct pci_dev *hwdev, size_t size,
 		    void *vaddr, dma_addr_t dma_handle)
 {
-	dma_free_coherent(hwdev == NULL ? NULL : &hwdev->dev, size, vaddr, dma_handle);
+	dma_free_coherent(&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 == NULL ? NULL : &hwdev->dev, ptr, size, (enum dma_data_direction)direction);
+	return dma_map_single(&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 == NULL ? NULL : &hwdev->dev, dma_addr, size, (enum dma_data_direction)direction);
+	dma_unmap_single(&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 == NULL ? NULL : &hwdev->dev, page, offset, size, (enum dma_data_direction)direction);
+	return dma_map_page(&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 == NULL ? NULL : &hwdev->dev, dma_address, size, (enum dma_data_direction)direction);
+	dma_unmap_page(&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 == NULL ? NULL : &hwdev->dev, sg, nents, (enum dma_data_direction)direction);
+	return dma_map_sg(&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 == NULL ? NULL : &hwdev->dev, sg, nents, (enum dma_data_direction)direction);
+	dma_unmap_sg(&hwdev->dev, sg, nents, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_dma_sync_single_for_cpu(struct pci_dev *hwdev, dma_addr_t dma_handle,
 		    size_t size, int direction)
 {
-	dma_sync_single_for_cpu(hwdev == NULL ? NULL : &hwdev->dev, dma_handle, size, (enum dma_data_direction)direction);
+	dma_sync_single_for_cpu(&hwdev->dev, dma_handle, size, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_dma_sync_single_for_device(struct pci_dev *hwdev, dma_addr_t dma_handle,
 		    size_t size, int direction)
 {
-	dma_sync_single_for_device(hwdev == NULL ? NULL : &hwdev->dev, dma_handle, size, (enum dma_data_direction)direction);
+	dma_sync_single_for_device(&hwdev->dev, dma_handle, size, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_dma_sync_sg_for_cpu(struct pci_dev *hwdev, struct scatterlist *sg,
 		int nelems, int direction)
 {
-	dma_sync_sg_for_cpu(hwdev == NULL ? NULL : &hwdev->dev, sg, nelems, (enum dma_data_direction)direction);
+	dma_sync_sg_for_cpu(&hwdev->dev, sg, nelems, (enum dma_data_direction)direction);
 }
 
 static inline void
 pci_dma_sync_sg_for_device(struct pci_dev *hwdev, struct scatterlist *sg,
 		int nelems, int direction)
 {
-	dma_sync_sg_for_device(hwdev == NULL ? NULL : &hwdev->dev, sg, nelems, (enum dma_data_direction)direction);
+	dma_sync_sg_for_device(&hwdev->dev, sg, nelems, (enum dma_data_direction)direction);
 }
 
 static inline int