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#ifndef _LINUX_PAGE_H
#define _LINUX_PAGE_H
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT 12
#define PAGE_SIZE ((unsigned long)1<<PAGE_SHIFT)
#ifdef __KERNEL__
/* number of bits that fit into a memory pointer */
#define BITS_PER_PTR (8*sizeof(unsigned long))
/* to mask away the intra-page address bits */
#define PAGE_MASK (~(PAGE_SIZE-1))
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)
/* to align the pointer to a pointer address */
#define PTR_MASK (~(sizeof(void*)-1))
/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
/* 64-bit machines, beware! SRB. */
#define SIZEOF_PTR_LOG2 2
/* to find an entry in a page-table-directory */
#define PAGE_DIR_OFFSET(base,address) ((unsigned long*)((base)+\
((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)*2&PTR_MASK&~PAGE_MASK)))
/* to find an entry in a page-table */
#define PAGE_PTR(address) \
((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
/* the no. of pointers that fit on a page */
#define PTRS_PER_PAGE (PAGE_SIZE/sizeof(void*))
#endif /* __KERNEL__ */
#endif /* _LINUX_PAGE_H */