Skip to content
Snippets Groups Projects
pgtable.h 20 KiB
Newer Older
  • Learn to ignore specific revisions
  • Linus Torvalds's avatar
    Linus Torvalds committed
    #ifndef _ASM_GENERIC_PGTABLE_H
    #define _ASM_GENERIC_PGTABLE_H
    
    
    #ifndef __ASSEMBLY__
    
    #include <linux/mm_types.h>
    
    #include <linux/bug.h>
    
    /*
     * On almost all architectures and configurations, 0 can be used as the
     * upper ceiling to free_pgtables(): on many architectures it has the same
     * effect as using TASK_SIZE.  However, there is one configuration which
     * must impose a more careful limit, to avoid freeing kernel pgtables.
     */
    #ifndef USER_PGTABLES_CEILING
    #define USER_PGTABLES_CEILING	0UL
    #endif
    
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
    
    extern int ptep_set_access_flags(struct vm_area_struct *vma,
    				 unsigned long address, pte_t *ptep,
    				 pte_t entry, int dirty);
    #endif
    
    #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
    extern int pmdp_set_access_flags(struct vm_area_struct *vma,
    				 unsigned long address, pmd_t *pmdp,
    				 pmd_t entry, int dirty);
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif
    
    #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
    
    static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
    					    unsigned long address,
    					    pte_t *ptep)
    {
    	pte_t pte = *ptep;
    	int r = 1;
    	if (!pte_young(pte))
    		r = 0;
    	else
    		set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
    	return r;
    }
    #endif
    
    #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
    #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
    					    unsigned long address,
    					    pmd_t *pmdp)
    {
    	pmd_t pmd = *pmdp;
    	int r = 1;
    	if (!pmd_young(pmd))
    		r = 0;
    	else
    		set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
    	return r;
    }
    #else /* CONFIG_TRANSPARENT_HUGEPAGE */
    static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
    					    unsigned long address,
    					    pmd_t *pmdp)
    {
    	BUG();
    	return 0;
    }
    #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif
    
    #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
    
    int ptep_clear_flush_young(struct vm_area_struct *vma,
    			   unsigned long address, pte_t *ptep);
    #endif
    
    #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
    int pmdp_clear_flush_young(struct vm_area_struct *vma,
    			   unsigned long address, pmd_t *pmdp);
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif
    
    #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
    
    static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
    				       unsigned long address,
    				       pte_t *ptep)
    {
    	pte_t pte = *ptep;
    	pte_clear(mm, address, ptep);
    	return pte;
    }
    #endif
    
    #ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR
    #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
    				       unsigned long address,
    				       pmd_t *pmdp)
    {
    	pmd_t pmd = *pmdp;
    
    #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif
    
    
    #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
    
    static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
    					    unsigned long address, pte_t *ptep,
    					    int full)
    {
    	pte_t pte;
    	pte = ptep_get_and_clear(mm, address, ptep);
    	return pte;
    }
    
    /*
     * Some architectures may be able to avoid expensive synchronization
     * primitives when modifications are made to PTE's which are already
     * not present, or in the process of an address space destruction.
     */
    #ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
    
    static inline void pte_clear_not_present_full(struct mm_struct *mm,
    					      unsigned long address,
    					      pte_t *ptep,
    					      int full)
    {
    	pte_clear(mm, address, ptep);
    }
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
    
    extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
    			      unsigned long address,
    			      pte_t *ptep);
    #endif
    
    #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
    extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
    			      unsigned long address,
    			      pmd_t *pmdp);
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif
    
    #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
    
    struct mm_struct;
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
    {
    	pte_t old_pte = *ptep;
    	set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
    }
    #endif
    
    
    #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
    #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    static inline void pmdp_set_wrprotect(struct mm_struct *mm,
    				      unsigned long address, pmd_t *pmdp)
    {
    	pmd_t old_pmd = *pmdp;
    	set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
    }
    #else /* CONFIG_TRANSPARENT_HUGEPAGE */
    static inline void pmdp_set_wrprotect(struct mm_struct *mm,
    				      unsigned long address, pmd_t *pmdp)
    {
    	BUG();
    }
    #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
    #endif
    
    #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
    
    extern void pmdp_splitting_flush(struct vm_area_struct *vma,
    				 unsigned long address, pmd_t *pmdp);
    
    #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
    
    extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
    				       pgtable_t pgtable);
    
    #endif
    
    #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
    
    extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
    
    #ifndef __HAVE_ARCH_PMDP_INVALIDATE
    extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
    			    pmd_t *pmdp);
    #endif
    
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #ifndef __HAVE_ARCH_PTE_SAME
    
    static inline int pte_same(pte_t pte_a, pte_t pte_b)
    {
    	return pte_val(pte_a) == pte_val(pte_b);
    }
    #endif
    
    #ifndef __HAVE_ARCH_PMD_SAME
    #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
    {
    	return pmd_val(pmd_a) == pmd_val(pmd_b);
    }
    #else /* CONFIG_TRANSPARENT_HUGEPAGE */
    static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
    {
    	BUG();
    	return 0;
    }
    #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif
    
    #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
    
    #define page_test_and_clear_young(pfn) (0)
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif
    
    #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
    #define pgd_offset_gate(mm, addr)	pgd_offset(mm, addr)
    #endif
    
    
    #ifndef __HAVE_ARCH_MOVE_PTE
    
    #define move_pte(pte, prot, old_addr, new_addr)	(pte)
    #endif
    
    
    #ifndef pte_accessible
    # define pte_accessible(pte)		((void)(pte),1)
    #endif
    
    
    #ifndef flush_tlb_fix_spurious_fault
    #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
    #endif
    
    
    #ifndef pgprot_noncached
    #define pgprot_noncached(prot)	(prot)
    #endif
    
    
    #ifndef pgprot_writecombine
    #define pgprot_writecombine pgprot_noncached
    #endif
    
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    /*
    
     * When walking page tables, get the address of the next boundary,
     * or the end address of the range if that comes earlier.  Although no
     * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
    
    Linus Torvalds's avatar
    Linus Torvalds committed
     */
    
    #define pgd_addr_end(addr, end)						\
    ({	unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;	\
    	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
    })
    
    #ifndef pud_addr_end
    #define pud_addr_end(addr, end)						\
    ({	unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;	\
    	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
    })
    #endif
    
    #ifndef pmd_addr_end
    #define pmd_addr_end(addr, end)						\
    ({	unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;	\
    	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
    })
    #endif
    
    /*
     * When walking page tables, we usually want to skip any p?d_none entries;
     * and any p?d_bad entries - reporting the error before resetting to none.
     * Do the tests inline, but report and clear the bad entry in mm/memory.c.
     */
    void pgd_clear_bad(pgd_t *);
    void pud_clear_bad(pud_t *);
    void pmd_clear_bad(pmd_t *);
    
    static inline int pgd_none_or_clear_bad(pgd_t *pgd)
    {
    	if (pgd_none(*pgd))
    		return 1;
    	if (unlikely(pgd_bad(*pgd))) {
    		pgd_clear_bad(pgd);
    		return 1;
    	}
    	return 0;
    }
    
    static inline int pud_none_or_clear_bad(pud_t *pud)
    {
    	if (pud_none(*pud))
    		return 1;
    	if (unlikely(pud_bad(*pud))) {
    		pud_clear_bad(pud);
    		return 1;
    	}
    	return 0;
    }
    
    static inline int pmd_none_or_clear_bad(pmd_t *pmd)
    {
    	if (pmd_none(*pmd))
    		return 1;
    	if (unlikely(pmd_bad(*pmd))) {
    		pmd_clear_bad(pmd);
    		return 1;
    	}
    	return 0;
    }
    
    static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
    					     unsigned long addr,
    					     pte_t *ptep)
    {
    	/*
    	 * Get the current pte state, but zero it out to make it
    	 * non-present, preventing the hardware from asynchronously
    	 * updating it.
    	 */
    	return ptep_get_and_clear(mm, addr, ptep);
    }
    
    static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
    					     unsigned long addr,
    					     pte_t *ptep, pte_t pte)
    {
    	/*
    	 * The pte is non-present, so there's no hardware state to
    	 * preserve.
    	 */
    	set_pte_at(mm, addr, ptep, pte);
    }
    
    #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
    /*
     * Start a pte protection read-modify-write transaction, which
     * protects against asynchronous hardware modifications to the pte.
     * The intention is not to prevent the hardware from making pte
     * updates, but to prevent any updates it may make from being lost.
     *
     * This does not protect against other software modifications of the
     * pte; the appropriate pte lock must be held over the transation.
     *
     * Note that this interface is intended to be batchable, meaning that
     * ptep_modify_prot_commit may not actually update the pte, but merely
     * queue the update to be done at some later time.  The update must be
     * actually committed before the pte lock is released, however.
     */
    static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
    					   unsigned long addr,
    					   pte_t *ptep)
    {
    	return __ptep_modify_prot_start(mm, addr, ptep);
    }
    
    /*
     * Commit an update to a pte, leaving any hardware-controlled bits in
     * the PTE unmodified.
     */
    static inline void ptep_modify_prot_commit(struct mm_struct *mm,
    					   unsigned long addr,
    					   pte_t *ptep, pte_t pte)
    {
    	__ptep_modify_prot_commit(mm, addr, ptep, pte);
    }
    #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
    
    #endif /* CONFIG_MMU */
    
    /*
     * A facility to provide lazy MMU batching.  This allows PTE updates and
     * page invalidations to be delayed until a call to leave lazy MMU mode
     * is issued.  Some architectures may benefit from doing this, and it is
     * beneficial for both shadow and direct mode hypervisors, which may batch
     * the PTE updates which happen during this window.  Note that using this
     * interface requires that read hazards be removed from the code.  A read
     * hazard could result in the direct mode hypervisor case, since the actual
     * write to the page tables may not yet have taken place, so reads though
     * a raw PTE pointer after it has been modified are not guaranteed to be
     * up to date.  This mode can only be entered and left under the protection of
     * the page table locks for all page tables which may be modified.  In the UP
     * case, this is required so that preemption is disabled, and in the SMP case,
     * it must synchronize the delayed page table writes properly on other CPUs.
     */
    #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
    #define arch_enter_lazy_mmu_mode()	do {} while (0)
    #define arch_leave_lazy_mmu_mode()	do {} while (0)
    #define arch_flush_lazy_mmu_mode()	do {} while (0)
    #endif
    
    /*
    
     * A facility to provide batching of the reload of page tables and
     * other process state with the actual context switch code for
     * paravirtualized guests.  By convention, only one of the batched
     * update (lazy) modes (CPU, MMU) should be active at any given time,
     * entry should never be nested, and entry and exits should always be
     * paired.  This is for sanity of maintaining and reasoning about the
     * kernel code.  In this case, the exit (end of the context switch) is
     * in architecture-specific code, and so doesn't need a generic
     * definition.
    
    #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
    
    #define arch_start_context_switch(prev)	do {} while (0)
    
    #ifndef CONFIG_HAVE_ARCH_SOFT_DIRTY
    static inline int pte_soft_dirty(pte_t pte)
    {
    	return 0;
    }
    
    static inline int pmd_soft_dirty(pmd_t pmd)
    {
    	return 0;
    }
    
    static inline pte_t pte_mksoft_dirty(pte_t pte)
    {
    	return pte;
    }
    
    static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
    {
    	return pmd;
    }
    
    
    static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
    {
    	return pte;
    }
    
    static inline int pte_swp_soft_dirty(pte_t pte)
    {
    	return 0;
    }
    
    static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
    {
    	return pte;
    }
    
    
    static inline pte_t pte_file_clear_soft_dirty(pte_t pte)
    {
           return pte;
    }
    
    static inline pte_t pte_file_mksoft_dirty(pte_t pte)
    {
           return pte;
    }
    
    static inline int pte_file_soft_dirty(pte_t pte)
    {
           return 0;
    }
    
     * Interfaces that can be used by architecture code to keep track of
     * memory type of pfn mappings specified by the remap_pfn_range,
     * vm_insert_pfn.
     */
    
    /*
     * track_pfn_remap is called when a _new_ pfn mapping is being established
     * by remap_pfn_range() for physical range indicated by pfn and size.
    
    static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
    
    				  unsigned long pfn, unsigned long addr,
    				  unsigned long size)
    
     * track_pfn_insert is called when a _new_ single pfn is established
     * by vm_insert_pfn().
     */
    static inline int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
    				   unsigned long pfn)
    {
    	return 0;
    }
    
    /*
     * track_pfn_copy is called when vma that is covering the pfnmap gets
    
    static inline int track_pfn_copy(struct vm_area_struct *vma)
    
    {
    	return 0;
    }
    
    /*
     * untrack_pfn_vma is called while unmapping a pfnmap for a region.
     * untrack can be called for a specific region indicated by pfn and size or
    
     * can be for the entire vma (in which case pfn, size are zero).
    
    static inline void untrack_pfn(struct vm_area_struct *vma,
    			       unsigned long pfn, unsigned long size)
    
    extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
    
    			   unsigned long pfn, unsigned long addr,
    			   unsigned long size);
    
    extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
    			    unsigned long pfn);
    extern int track_pfn_copy(struct vm_area_struct *vma);
    extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
    			unsigned long size);
    
    #ifdef __HAVE_COLOR_ZERO_PAGE
    static inline int is_zero_pfn(unsigned long pfn)
    {
    	extern unsigned long zero_pfn;
    	unsigned long offset_from_zero_pfn = pfn - zero_pfn;
    	return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
    }
    
    
    #define my_zero_pfn(addr)	page_to_pfn(ZERO_PAGE(addr))
    
    
    #else
    static inline int is_zero_pfn(unsigned long pfn)
    {
    	extern unsigned long zero_pfn;
    	return pfn == zero_pfn;
    }
    
    static inline unsigned long my_zero_pfn(unsigned long addr)
    {
    	extern unsigned long zero_pfn;
    	return zero_pfn;
    }
    #endif
    
    
    #ifndef CONFIG_TRANSPARENT_HUGEPAGE
    static inline int pmd_trans_huge(pmd_t pmd)
    {
    	return 0;
    }
    static inline int pmd_trans_splitting(pmd_t pmd)
    {
    	return 0;
    }
    
    #ifndef __HAVE_ARCH_PMD_WRITE
    static inline int pmd_write(pmd_t pmd)
    {
    	BUG();
    	return 0;
    }
    #endif /* __HAVE_ARCH_PMD_WRITE */
    
    #ifndef pmd_read_atomic
    static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
    {
    	/*
    	 * Depend on compiler for an atomic pmd read. NOTE: this is
    	 * only going to work, if the pmdval_t isn't larger than
    	 * an unsigned long.
    	 */
    	return *pmdp;
    }
    #endif
    
    
    /*
     * This function is meant to be used by sites walking pagetables with
     * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
     * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
     * into a null pmd and the transhuge page fault can convert a null pmd
     * into an hugepmd or into a regular pmd (if the hugepage allocation
     * fails). While holding the mmap_sem in read mode the pmd becomes
     * stable and stops changing under us only if it's not null and not a
     * transhuge pmd. When those races occurs and this function makes a
     * difference vs the standard pmd_none_or_clear_bad, the result is
     * undefined so behaving like if the pmd was none is safe (because it
     * can return none anyway). The compiler level barrier() is critically
     * important to compute the two checks atomically on the same pmdval.
    
     *
     * For 32bit kernels with a 64bit large pmd_t this automatically takes
     * care of reading the pmd atomically to avoid SMP race conditions
     * against pmd_populate() when the mmap_sem is hold for reading by the
     * caller (a special atomic read not done by "gcc" as in the generic
     * version above, is also needed when THP is disabled because the page
     * fault can populate the pmd from under us).
    
     */
    static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
    {
    
    	/*
    	 * The barrier will stabilize the pmdval in a register or on
    	 * the stack so that it will stop changing under the code.
    
    	 *
    	 * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
    	 * pmd_read_atomic is allowed to return a not atomic pmdval
    	 * (for example pointing to an hugepage that has never been
    	 * mapped in the pmd). The below checks will only care about
    	 * the low part of the pmd with 32bit PAE x86 anyway, with the
    	 * exception of pmd_none(). So the important thing is that if
    	 * the low part of the pmd is found null, the high part will
    	 * be also null or the pmd_none() check below would be
    	 * confused.
    
    	 */
    #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    	barrier();
    #endif
    	if (pmd_none(pmdval))
    		return 1;
    	if (unlikely(pmd_bad(pmdval))) {
    		if (!pmd_trans_huge(pmdval))
    			pmd_clear_bad(pmd);
    		return 1;
    	}
    	return 0;
    }
    
    /*
     * This is a noop if Transparent Hugepage Support is not built into
     * the kernel. Otherwise it is equivalent to
     * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
     * places that already verified the pmd is not none and they want to
     * walk ptes while holding the mmap sem in read mode (write mode don't
     * need this). If THP is not enabled, the pmd can't go away under the
     * code even if MADV_DONTNEED runs, but if THP is enabled we need to
     * run a pmd_trans_unstable before walking the ptes after
     * split_huge_page_pmd returns (because it may have run when the pmd
     * become null, but then a page fault can map in a THP and not a
     * regular page).
     */
    static inline int pmd_trans_unstable(pmd_t *pmd)
    {
    #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    	return pmd_none_or_trans_huge_or_clear_bad(pmd);
    #else
    	return 0;
    
    #ifdef CONFIG_NUMA_BALANCING
    #ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
    /*
     * _PAGE_NUMA works identical to _PAGE_PROTNONE (it's actually the
     * same bit too). It's set only when _PAGE_PRESET is not set and it's
     * never set if _PAGE_PRESENT is set.
     *
     * pte/pmd_present() returns true if pte/pmd_numa returns true. Page
     * fault triggers on those regions if pte/pmd_numa returns true
     * (because _PAGE_PRESENT is not set).
     */
    #ifndef pte_numa
    static inline int pte_numa(pte_t pte)
    {
    	return (pte_flags(pte) &
    		(_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
    }
    #endif
    
    #ifndef pmd_numa
    static inline int pmd_numa(pmd_t pmd)
    {
    	return (pmd_flags(pmd) &
    		(_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
    }
    #endif
    
    /*
     * pte/pmd_mknuma sets the _PAGE_ACCESSED bitflag automatically
     * because they're called by the NUMA hinting minor page fault. If we
     * wouldn't set the _PAGE_ACCESSED bitflag here, the TLB miss handler
     * would be forced to set it later while filling the TLB after we
     * return to userland. That would trigger a second write to memory
     * that we optimize away by setting _PAGE_ACCESSED here.
     */
    #ifndef pte_mknonnuma
    static inline pte_t pte_mknonnuma(pte_t pte)
    {
    	pte = pte_clear_flags(pte, _PAGE_NUMA);
    	return pte_set_flags(pte, _PAGE_PRESENT|_PAGE_ACCESSED);
    }
    #endif
    
    #ifndef pmd_mknonnuma
    static inline pmd_t pmd_mknonnuma(pmd_t pmd)
    {
    	pmd = pmd_clear_flags(pmd, _PAGE_NUMA);
    	return pmd_set_flags(pmd, _PAGE_PRESENT|_PAGE_ACCESSED);
    }
    #endif
    
    #ifndef pte_mknuma
    static inline pte_t pte_mknuma(pte_t pte)
    {
    	pte = pte_set_flags(pte, _PAGE_NUMA);
    	return pte_clear_flags(pte, _PAGE_PRESENT);
    }
    #endif
    
    #ifndef pmd_mknuma
    static inline pmd_t pmd_mknuma(pmd_t pmd)
    {
    	pmd = pmd_set_flags(pmd, _PAGE_NUMA);
    	return pmd_clear_flags(pmd, _PAGE_PRESENT);
    }
    #endif
    #else
    extern int pte_numa(pte_t pte);
    extern int pmd_numa(pmd_t pmd);
    extern pte_t pte_mknonnuma(pte_t pte);
    extern pmd_t pmd_mknonnuma(pmd_t pmd);
    extern pte_t pte_mknuma(pte_t pte);
    extern pmd_t pmd_mknuma(pmd_t pmd);
    #endif /* CONFIG_ARCH_USES_NUMA_PROT_NONE */
    #else
    static inline int pmd_numa(pmd_t pmd)
    {
    	return 0;
    }
    
    static inline int pte_numa(pte_t pte)
    {
    	return 0;
    }
    
    static inline pte_t pte_mknonnuma(pte_t pte)
    {
    	return pte;
    }
    
    static inline pmd_t pmd_mknonnuma(pmd_t pmd)
    {
    	return pmd;
    }
    
    static inline pte_t pte_mknuma(pte_t pte)
    {
    	return pte;
    }
    
    static inline pmd_t pmd_mknuma(pmd_t pmd)
    {
    	return pmd;
    }
    #endif /* CONFIG_NUMA_BALANCING */
    
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif /* !__ASSEMBLY__ */
    
    
    #ifndef io_remap_pfn_range
    #define io_remap_pfn_range remap_pfn_range
    #endif
    
    
    Linus Torvalds's avatar
    Linus Torvalds committed
    #endif /* _ASM_GENERIC_PGTABLE_H */