#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_PMDP_SET_ACCESS_FLAGS
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define pmdp_set_access_flags(__vma, __address, __pmdp, __entry, __dirty) \
({ \
int __changed = !pmd_same(*(__pmdp), __entry); \
VM_BUG_ON((__address) & ~HPAGE_PMD_MASK); \
if (__changed) { \
set_pmd_at((__vma)->vm_mm, __address, __pmdp, \
__entry); \
flush_tlb_range(__vma, __address, \
(__address) + HPAGE_PMD_SIZE); \
} \
__changed; \
})
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define pmdp_set_access_flags(__vma, __address, __pmdp, __entry, __dirty) \
({ BUG(); 0; })
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#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_PMDP_TEST_AND_CLEAR_YOUNG
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define pmdp_test_and_clear_young(__vma, __address, __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)); \
r; \
})
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define pmdp_test_and_clear_young(__vma, __address, __pmdp) \
({ BUG(); 0; })
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#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_PMDP_CLEAR_YOUNG_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define pmdp_clear_flush_young(__vma, __address, __pmdp) \
({ \
int __young; \
VM_BUG_ON((__address) & ~HPAGE_PMD_MASK); \
__young = pmdp_test_and_clear_young(__vma, __address, __pmdp); \
if (__young) \
flush_tlb_range(__vma, __address, \
(__address) + HPAGE_PMD_SIZE); \
__young; \
})
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define pmdp_clear_flush_young(__vma, __address, __pmdp) \
({ BUG(); 0; })
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#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_PMDP_GET_AND_CLEAR
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define pmdp_get_and_clear(__mm, __address, __pmdp) \
({ \
pmd_t __pmd = *(__pmdp); \
pmd_clear((__mm), (__address), (__pmdp)); \
__pmd; \
})
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define pmdp_get_and_clear(__mm, __address, __pmdp) \
({ BUG(); 0; })
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#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_PMDP_CLEAR_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define pmdp_clear_flush(__vma, __address, __pmdp) \
({ \
pmd_t __pmd; \
VM_BUG_ON((__address) & ~HPAGE_PMD_MASK); \
__pmd = pmdp_get_and_clear((__vma)->vm_mm, __address, __pmdp); \
flush_tlb_range(__vma, __address, (__address) + HPAGE_PMD_SIZE);\
__pmd; \
})
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define pmdp_clear_flush(__vma, __address, __pmdp) \
({ BUG(); 0; })
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#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_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 */
#define pmdp_set_wrprotect(mm, address, pmdp) BUG()
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define pmdp_splitting_flush(__vma, __address, __pmdp) \
({ \
pmd_t __pmd = pmd_mksplitting(*(__pmdp)); \
VM_BUG_ON((__address) & ~HPAGE_PMD_MASK); \
set_pmd_at((__vma)->vm_mm, __address, __pmdp, __pmd); \
/* tlb flush only to serialize against gup-fast */ \
flush_tlb_range(__vma, __address, (__address) + HPAGE_PMD_SIZE);\
})
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define pmdp_splitting_flush(__vma, __address, __pmdp) BUG()
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PTE_SAME
#define pte_same(A,B) (pte_val(A) == pte_val(B))
#endif
#ifndef __HAVE_ARCH_PMD_SAME
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define pmd_same(A,B) (pmd_val(A) == pmd_val(B))
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define pmd_same(A,B) ({ BUG(); 0; })
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#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.
*/
#ifdef CONFIG_PARAVIRT
if (likely(!paravirt_enabled()))
native_set_pte_at(mm, addr, ptep, pte);
else
#endif
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
#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);
}
static inline unsigned long my_zero_pfn(unsigned long addr)
{
return 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
#define pmd_trans_huge(pmd) 0
#define pmd_trans_splitting(pmd) (0)
#ifndef __HAVE_ARCH_PMD_WRITE
#define pmd_write(pmd) ({ BUG(); 0; })
#endif /* __HAVE_ARCH_PMD_WRITE */
#endif
#ifndef __HAVE_ARCH_READ_PMD_ATOMIC
static inline pmd_t read_pmd_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 /* __HAVE_ARCH_READ_PMD */
/*
* 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)
{
pmd_t pmdval = read_pmd_atomic(pmd);
/*
* The barrier will stabilize the pmdval in a register or on
* the stack so that it will stop changing under the code.
*/
#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;
#endif
}
#endif /* !__ASSEMBLY__ */
#ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
{
return true;
}
static inline bool arch_has_pfn_modify_check(void)
{
return false;
}
#endif
#endif /* _ASM_GENERIC_PGTABLE_H */
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