#ifndef _ASM_GENERIC_PGTABLE_H
#define _ASM_GENERIC_PGTABLE_H

#ifndef __ASSEMBLY__
#ifdef CONFIG_MMU

#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
/*
 * Largely same as above, but only sets the access flags (dirty,
 * accessed, and writable). Furthermore, we know it always gets set
 * to a "more permissive" setting, which allows most architectures
 * to optimize this. We return whether the PTE actually changed, which
 * in turn instructs the caller to do things like update__mmu_cache.
 * This used to be done in the caller, but sparc needs minor faults to
 * force that call on sun4c so we changed this macro slightly
 */
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
({                                                                        \
        int __changed = !pte_same(*(__ptep), __entry);                    \
        if (__changed) {                                                  \
                set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
                flush_tlb_page(__vma, __address);                         \
        }                                                                 \
        __changed;                                                        \
})
#endif

#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define ptep_test_and_clear_young(__vma, __address, __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));                 \
        r;                                                              \
})
#endif

#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
#define ptep_clear_flush_young(__vma, __address, __ptep)                \
({                                                                      \
        int __young;                                                    \
        __young = ptep_test_and_clear_young(__vma, __address, __ptep);  \
        if (__young)                                                    \
                flush_tlb_page(__vma, __address);                       \
        __young;                                                        \
})
#endif

#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define ptep_get_and_clear(__mm, __address, __ptep)                     \
({                                                                      \
        pte_t __pte = *(__ptep);                                        \
        pte_clear((__mm), (__address), (__ptep));                       \
        __pte;                                                          \
})
#endif

#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
#define ptep_get_and_clear_full(__mm, __address, __ptep, __full)        \
({                                                                      \
        pte_t __pte;                                                    \
        __pte = ptep_get_and_clear((__mm), (__address), (__ptep));      \
        __pte;                                                          \
})
#endif

/*
 * 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
#define pte_clear_not_present_full(__mm, __address, __ptep, __full)     \
do {                                                                    \
        pte_clear((__mm), (__address), (__ptep));                       \
} while (0)
#endif

#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
#define ptep_clear_flush(__vma, __address, __ptep)                      \
({                                                                      \
        pte_t __pte;                                                    \
        __pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep);  \
        flush_tlb_page(__vma, __address);                               \
        __pte;                                                          \
})
#endif

#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
struct mm_struct;
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_PTE_SAME
#define pte_same(A,B)   (pte_val(A) == pte_val(B))
#endif

#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
#define page_test_dirty(page)           (0)
#endif

#ifndef __HAVE_ARCH_PAGE_CLEAR_DIRTY
#define page_clear_dirty(page)          do { } while (0)
#endif

#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
#define pte_maybe_dirty(pte)            pte_dirty(pte)
#else
#define pte_maybe_dirty(pte)            (1)
#endif

#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
#define page_test_and_clear_young(page) (0)
#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 pgprot_noncached
#define pgprot_noncached(prot)  (prot)
#endif

#ifndef pgprot_writecombine
#define pgprot_writecombine pgprot_noncached
#endif

/*
 * 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.
 */

#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)
#endif

#ifndef __HAVE_PFNMAP_TRACKING
/*
 * Interface that can be used by architecture code to keep track of
 * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
 *
 * track_pfn_vma_new is called when a _new_ pfn mapping is being established
 * for physical range indicated by pfn and size.
 */
static inline int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
                                        unsigned long pfn, unsigned long size)
{
        return 0;
}

/*
 * Interface that can be used by architecture code to keep track of
 * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
 *
 * track_pfn_vma_copy is called when vma that is covering the pfnmap gets
 * copied through copy_page_range().
 */
static inline int track_pfn_vma_copy(struct vm_area_struct *vma)
{
        return 0;
}

/*
 * Interface that can be used by architecture code to keep track of
 * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
 *
 * 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 size can be zero).
 */
static inline void untrack_pfn_vma(struct vm_area_struct *vma,
                                        unsigned long pfn, unsigned long size)
{
}
#else
extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
                                unsigned long pfn, unsigned long size);
extern int track_pfn_vma_copy(struct vm_area_struct *vma);
extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
                                unsigned long size);
#endif

#endif /* !__ASSEMBLY__ */

#endif /* _ASM_GENERIC_PGTABLE_H */