| #ifndef _LINUX_IOMMU_HELPER_H | 
 | #define _LINUX_IOMMU_HELPER_H | 
 |  | 
 | #include <linux/kernel.h> | 
 |  | 
 | static inline unsigned long iommu_device_max_index(unsigned long size, | 
 | 						   unsigned long offset, | 
 | 						   u64 dma_mask) | 
 | { | 
 | 	if (size + offset > dma_mask) | 
 | 		return dma_mask - offset + 1; | 
 | 	else | 
 | 		return size; | 
 | } | 
 |  | 
 | extern int iommu_is_span_boundary(unsigned int index, unsigned int nr, | 
 | 				  unsigned long shift, | 
 | 				  unsigned long boundary_size); | 
 | extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, | 
 | 				      unsigned long start, unsigned int nr, | 
 | 				      unsigned long shift, | 
 | 				      unsigned long boundary_size, | 
 | 				      unsigned long align_mask); | 
 |  | 
 | static inline unsigned long iommu_num_pages(unsigned long addr, | 
 | 					    unsigned long len, | 
 | 					    unsigned long io_page_size) | 
 | { | 
 | 	unsigned long size = (addr & (io_page_size - 1)) + len; | 
 |  | 
 | 	return DIV_ROUND_UP(size, io_page_size); | 
 | } | 
 |  | 
 | #endif |