original_kernel/include/asm-ppc/page.h

#ifndef _PPC_PAGE_H
#define _PPC_PAGE_H

/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT	12
#define PAGE_SIZE	(1UL << PAGE_SHIFT)

/*
 * Subtle: this is an int (not an unsigned long) and so it
 * gets extended to 64 bits the way want (i.e. with 1s).  -- paulus
 */
#define PAGE_MASK	(~((1 << PAGE_SHIFT) - 1))

#ifdef __KERNEL__
#include <linux/config.h>

/* This must match what is in arch/ppc/Makefile */
#define PAGE_OFFSET	CONFIG_KERNEL_START
#define KERNELBASE	PAGE_OFFSET

#ifndef __ASSEMBLY__

/*
 * The basic type of a PTE - 64 bits for those CPUs with > 32 bit
 * physical addressing.  For now this just the IBM PPC440.
 */
#ifdef CONFIG_PTE_64BIT
typedef unsigned long long pte_basic_t;
#define PTE_SHIFT	(PAGE_SHIFT - 3)	/* 512 ptes per page */
#define PTE_FMT		"%16Lx"
#else
typedef unsigned long pte_basic_t;
#define PTE_SHIFT	(PAGE_SHIFT - 2)	/* 1024 ptes per page */
#define PTE_FMT		"%.8lx"
#endif

/* align addr on a size boundary - adjust address up/down if needed */
#define _ALIGN_UP(addr,size)	(((addr)+((size)-1))&(~((size)-1)))
#define _ALIGN_DOWN(addr,size)	((addr)&(~((size)-1)))

/* align addr on a size boundary - adjust address up if needed */
#define _ALIGN(addr,size)     _ALIGN_UP(addr,size)

/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr)	_ALIGN(addr, PAGE_SIZE)


#undef STRICT_MM_TYPECHECKS

#ifdef STRICT_MM_TYPECHECKS
/*
 * These are used to make use of C type-checking..
 */
typedef struct { pte_basic_t pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pgd; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;

#define pte_val(x)	((x).pte)
#define pmd_val(x)	((x).pmd)
#define pgd_val(x)	((x).pgd)
#define pgprot_val(x)	((x).pgprot)

#define __pte(x)	((pte_t) { (x) } )
#define __pmd(x)	((pmd_t) { (x) } )
#define __pgd(x)	((pgd_t) { (x) } )
#define __pgprot(x)	((pgprot_t) { (x) } )

#else
/*
 * .. while these make it easier on the compiler
 */
typedef pte_basic_t pte_t;
typedef unsigned long pmd_t;
typedef unsigned long pgd_t;
typedef unsigned long pgprot_t;

#define pte_val(x)	(x)
#define pmd_val(x)	(x)
#define pgd_val(x)	(x)
#define pgprot_val(x)	(x)

#define __pte(x)	(x)
#define __pmd(x)	(x)
#define __pgd(x)	(x)
#define __pgprot(x)	(x)

#endif

struct page;
extern void clear_pages(void *page, int order);
static inline void clear_page(void *page) { clear_pages(page, 0); }
extern void copy_page(void *to, void *from);
extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
extern void copy_user_page(void *to, void *from, unsigned long vaddr,
			   struct page *pg);

#ifndef CONFIG_APUS
#define PPC_MEMSTART	0
#define PPC_PGSTART	0
#define PPC_MEMOFFSET	PAGE_OFFSET
#else
extern unsigned long ppc_memstart;
extern unsigned long ppc_pgstart;
extern unsigned long ppc_memoffset;
#define PPC_MEMSTART	ppc_memstart
#define PPC_PGSTART	ppc_pgstart
#define PPC_MEMOFFSET	ppc_memoffset
#endif

#if defined(CONFIG_APUS) && !defined(MODULE)
/* map phys->virtual and virtual->phys for RAM pages */
static inline unsigned long ___pa(unsigned long v)
{
	unsigned long p;
	asm volatile ("1: addis %0, %1, %2;"
		      ".section \".vtop_fixup\",\"aw\";"
		      ".align  1;"
		      ".long   1b;"
		      ".previous;"
		      : "=r" (p)
		      : "b" (v), "K" (((-PAGE_OFFSET) >> 16) & 0xffff));

	return p;
}
static inline void* ___va(unsigned long p)
{
	unsigned long v;
	asm volatile ("1: addis %0, %1, %2;"
		      ".section \".ptov_fixup\",\"aw\";"
		      ".align  1;"
		      ".long   1b;"
		      ".previous;"
		      : "=r" (v)
		      : "b" (p), "K" (((PAGE_OFFSET) >> 16) & 0xffff));

	return (void*) v;
}
#else
#define ___pa(vaddr) ((vaddr)-PPC_MEMOFFSET)
#define ___va(paddr) ((paddr)+PPC_MEMOFFSET)
#endif

extern int page_is_ram(unsigned long pfn);

#define __pa(x) ___pa((unsigned long)(x))
#define __va(x) ((void *)(___va((unsigned long)(x))))

#define pfn_to_page(pfn)	(mem_map + ((pfn) - PPC_PGSTART))
#define page_to_pfn(page)	((unsigned long)((page) - mem_map) + PPC_PGSTART)
#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define page_to_virt(page)	__va(page_to_pfn(page) << PAGE_SHIFT)

#define pfn_valid(pfn)		(((pfn) - PPC_PGSTART) < max_mapnr)
#define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)

/* Pure 2^n version of get_order */
extern __inline__ int get_order(unsigned long size)
{
	int lz;

	size = (size-1) >> PAGE_SHIFT;
	asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
	return 32 - lz;
}

#endif /* __ASSEMBLY__ */

#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)

#endif /* __KERNEL__ */
#endif /* _PPC_PAGE_H */