/*
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   * Copyright (C) 1994 - 1999, 2000, 03 Ralf Baechle
   * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   */
  #ifndef _ASM_PAGE_H
  #define _ASM_PAGE_H

  
  #ifdef __KERNEL__
  
  #include <spaces.h>
  
  #endif
  
  /*
   * PAGE_SHIFT determines the page size
   */
  #ifdef CONFIG_PAGE_SIZE_4KB
  #define PAGE_SHIFT	12
  #endif
  #ifdef CONFIG_PAGE_SIZE_8KB
  #define PAGE_SHIFT	13
  #endif
  #ifdef CONFIG_PAGE_SIZE_16KB
  #define PAGE_SHIFT	14
  #endif
  #ifdef CONFIG_PAGE_SIZE_64KB
  #define PAGE_SHIFT	16
  #endif
  #define PAGE_SIZE	(1UL << PAGE_SHIFT)
  #define PAGE_MASK       (~((1 << PAGE_SHIFT) - 1))
  
  
  #ifdef __KERNEL__
  #ifndef __ASSEMBLY__
  
  extern void clear_page(void * page);
  extern void copy_page(void * to, void * from);
  
  extern unsigned long shm_align_mask;
  
  static inline unsigned long pages_do_alias(unsigned long addr1,
  	unsigned long addr2)
  {
  	return (addr1 ^ addr2) & shm_align_mask;
  }
  
  struct page;
  
  static inline void clear_user_page(void *addr, unsigned long vaddr,
  	struct page *page)
  {
  	extern void (*flush_data_cache_page)(unsigned long addr);
  
  	clear_page(addr);
  	if (pages_do_alias((unsigned long) addr, vaddr))
  		flush_data_cache_page((unsigned long)addr);
  }
  
  static inline void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
  	struct page *to)
  {
  	extern void (*flush_data_cache_page)(unsigned long addr);
  
  	copy_page(vto, vfrom);
  	if (pages_do_alias((unsigned long)vto, vaddr))
  		flush_data_cache_page((unsigned long)vto);
  }
  
  /*
   * These are used to make use of C type-checking..
   */
  #ifdef CONFIG_64BIT_PHYS_ADDR

    #ifdef CONFIG_CPU_MIPS32

      typedef struct { unsigned long pte_low, pte_high; } pte_t;
      #define pte_val(x)    ((x).pte_low | ((unsigned long long)(x).pte_high << 32))
    #else
       typedef struct { unsigned long long pte; } pte_t;
       #define pte_val(x)	((x).pte)
    #endif
  #else
  typedef struct { unsigned long pte; } pte_t;
  #define pte_val(x)	((x).pte)
  #endif

  #define __pte(x)	((pte_t) { (x) } )

  /*
   * For 3-level pagetables we defines these ourselves, for 2-level the
   * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
   */
  #ifdef CONFIG_64BIT

  typedef struct { unsigned long pmd; } pmd_t;

  #define pmd_val(x)	((x).pmd)

  #define __pmd(x)	((pmd_t) { (x) } )

  #endif

  /*
   * Right now we don't support 4-level pagetables, so all pud-related
   * definitions come from <asm-generic/pgtable-nopud.h>.
   */
  
  /*
   * Finall the top of the hierarchy, the pgd
   */
  typedef struct { unsigned long pgd; } pgd_t;
  #define pgd_val(x)	((x).pgd)

  #define __pgd(x)	((pgd_t) { (x) } )

  
  /*
   * Manipulate page protection bits
   */
  typedef struct { unsigned long pgprot; } pgprot_t;
  #define pgprot_val(x)	((x).pgprot)

  #define __pgprot(x)	((pgprot_t) { (x) } )

  /*
   * On R4000-style MMUs where a TLB entry is mapping a adjacent even / odd
   * pair of pages we only have a single global bit per pair of pages.  When
   * writing to the TLB make sure we always have the bit set for both pages
   * or none.  This macro is used to access the `buddy' of the pte we're just
   * working on.
   */
  #define ptep_buddy(x)	((pte_t *)((unsigned long)(x) ^ sizeof(pte_t)))

  #endif /* !__ASSEMBLY__ */
  
  /* to align the pointer to the (next) page boundary */
  #define PAGE_ALIGN(addr)	(((addr) + PAGE_SIZE - 1) & PAGE_MASK)
  
  #define __pa(x)			((unsigned long) (x) - PAGE_OFFSET)
  #define __va(x)			((void *)((unsigned long) (x) + PAGE_OFFSET))
  
  #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)

  #ifndef CONFIG_SPARSEMEM

  #ifndef CONFIG_NEED_MULTIPLE_NODES

  #define pfn_valid(pfn)		((pfn) < max_mapnr)
  #endif

  #endif

  #ifdef CONFIG_FLATMEM
  
  #define pfn_valid(pfn)		((pfn) < max_mapnr)
  
  #elif defined(CONFIG_NEED_MULTIPLE_NODES)
  
  #define pfn_valid(pfn)							\
  ({									\
  	unsigned long __pfn = (pfn);					\
  	int __n = pfn_to_nid(__pfn);					\
  	((__n >= 0) ? (__pfn < NODE_DATA(__n)->node_start_pfn +		\
  	                       NODE_DATA(__n)->node_spanned_pages)	\
  	            : 0);						\
  })
  
  #else
  #error Provide a definition of pfn_valid
  #endif

  #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  
  #define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
  				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  
  #define UNCAC_ADDR(addr)	((addr) - PAGE_OFFSET + UNCAC_BASE)
  #define CAC_ADDR(addr)		((addr) - UNCAC_BASE + PAGE_OFFSET)
  
  #endif /* defined (__KERNEL__) */
  
  #ifdef CONFIG_LIMITED_DMA
  #define WANT_PAGE_VIRTUAL
  #endif

  #include <asm-generic/memory_model.h>

  #include <asm-generic/page.h>

  #endif /* _ASM_PAGE_H */