1. 根目录:
2. include
3. asm-generic
4. pci-dma-compat.h

/* include this file if the platform implements the dma_ DMA Mapping API
 * and wants to provide the pci_ DMA Mapping API in terms of it */

#ifndef _ASM_GENERIC_PCI_DMA_COMPAT_H
#define _ASM_GENERIC_PCI_DMA_COMPAT_H

#include <linux/dma-mapping.h>

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

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);
}

static inline int
pci_dma_mapping_error(struct pci_dev *pdev, dma_addr_t dma_addr)
{
	return dma_mapping_error(&pdev->dev, dma_addr);
}

#ifdef CONFIG_PCI
static inline int pci_set_dma_mask(struct pci_dev *dev, u64 mask)
{
	return dma_set_mask(&dev->dev, mask);
}

static inline int pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
{
	return dma_set_coherent_mask(&dev->dev, mask);
}
#endif

#endif