arch/powerpc/include/asm/book3s/64/hash-64k.h - kernel/msm-4.9 - Gitiles

 #ifndef _ASM_POWERPC_BOOK3S_64_HASH_64K_H
 #define _ASM_POWERPC_BOOK3S_64_HASH_64K_H

 #define PTE_INDEX_SIZE  8
 #define PMD_INDEX_SIZE  5
 #define PUD_INDEX_SIZE	5
 #define PGD_INDEX_SIZE  12

 #define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
 #define PTRS_PER_PMD	(1 << PMD_INDEX_SIZE)
 #define PTRS_PER_PUD	(1 << PUD_INDEX_SIZE)
 #define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)

 /* With 4k base page size, hugepage PTEs go at the PMD level */
 #define MIN_HUGEPTE_SHIFT	PAGE_SHIFT

 /* PMD_SHIFT determines what a second-level page table entry can map */
 #define PMD_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
 #define PMD_SIZE	(1UL << PMD_SHIFT)
 #define PMD_MASK	(~(PMD_SIZE-1))

 /* PUD_SHIFT determines what a third-level page table entry can map */
 #define PUD_SHIFT	(PMD_SHIFT + PMD_INDEX_SIZE)
 #define PUD_SIZE	(1UL << PUD_SHIFT)
 #define PUD_MASK	(~(PUD_SIZE-1))

 /* PGDIR_SHIFT determines what a fourth-level page table entry can map */
 #define PGDIR_SHIFT	(PUD_SHIFT + PUD_INDEX_SIZE)
 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))

 #define H_PAGE_COMBO	0x00001000 /* this is a combo 4k page */
 #define H_PAGE_4K_PFN	0x00002000 /* PFN is for a single 4k page */
 /*
  * We need to differentiate between explicit huge page and THP huge
  * page, since THP huge page also need to track real subpage details
  */
 #define H_PAGE_THP_HUGE  H_PAGE_4K_PFN

 /*
  * Used to track subpage group valid if H_PAGE_COMBO is set
  * This overloads H_PAGE_F_GIX and H_PAGE_F_SECOND
  */
 #define H_PAGE_COMBO_VALID	(H_PAGE_F_GIX | H_PAGE_F_SECOND)

 /* PTE flags to conserve for HPTE identification */
 #define _PAGE_HPTEFLAGS (H_PAGE_BUSY | H_PAGE_F_SECOND | \
 			 H_PAGE_F_GIX | H_PAGE_HASHPTE | H_PAGE_COMBO)
 /*
  * we support 16 fragments per PTE page of 64K size.
  */
 #define PTE_FRAG_NR	16
 /*
  * We use a 2K PTE page fragment and another 2K for storing
  * real_pte_t hash index
  */
 #define PTE_FRAG_SIZE_SHIFT  12
 #define PTE_FRAG_SIZE (1UL << PTE_FRAG_SIZE_SHIFT)

 /* Bits to mask out from a PMD to get to the PTE page */
 #define PMD_MASKED_BITS		0xc0000000000000ffUL
 /* Bits to mask out from a PUD to get to the PMD page */
 #define PUD_MASKED_BITS		0xc0000000000000ffUL
 /* Bits to mask out from a PGD to get to the PUD page */
 #define PGD_MASKED_BITS		0xc0000000000000ffUL

 #ifndef __ASSEMBLY__
 #include <asm/errno.h>

 /*
  * With 64K pages on hash table, we have a special PTE format that
  * uses a second "half" of the page table to encode sub-page information
  * in order to deal with 64K made of 4K HW pages. Thus we override the
  * generic accessors and iterators here
  */
 #define __real_pte __real_pte
 static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep)
 {
 	real_pte_t rpte;
 	unsigned long *hidxp;

 	rpte.pte = pte;
 	rpte.hidx = 0;
 	if (pte_val(pte) & H_PAGE_COMBO) {
 		/*
 		 * Make sure we order the hidx load against the H_PAGE_COMBO
 		 * check. The store side ordering is done in __hash_page_4K
 		 */
 		smp_rmb();
 		hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
 		rpte.hidx = *hidxp;
 	}
 	return rpte;
 }

 static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
 {
 	if ((pte_val(rpte.pte) & H_PAGE_COMBO))
 		return (rpte.hidx >> (index<<2)) & 0xf;
 	return (pte_val(rpte.pte) >> H_PAGE_F_GIX_SHIFT) & 0xf;
 }

 #define __rpte_to_pte(r)	((r).pte)
 extern bool __rpte_sub_valid(real_pte_t rpte, unsigned long index);
 /*
  * Trick: we set __end to va + 64k, which happens works for
  * a 16M page as well as we want only one iteration
  */
 #define pte_iterate_hashed_subpages(rpte, psize, vpn, index, shift)	\
 	do {								\
 		unsigned long __end = vpn + (1UL << (PAGE_SHIFT - VPN_SHIFT));	\
 		unsigned __split = (psize == MMU_PAGE_4K ||		\
 				    psize == MMU_PAGE_64K_AP);		\
 		shift = mmu_psize_defs[psize].shift;			\
 		for (index = 0; vpn < __end; index++,			\
 			     vpn += (1L << (shift - VPN_SHIFT))) {	\
 			if (!__split || __rpte_sub_valid(rpte, index))	\
 				do {

 #define pte_iterate_hashed_end() } while(0); } } while(0)

 #define pte_pagesize_index(mm, addr, pte)	\
 	(((pte) & H_PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K)

 extern int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
 			   unsigned long pfn, unsigned long size, pgprot_t);
 static inline int remap_4k_pfn(struct vm_area_struct *vma, unsigned long addr,
 			       unsigned long pfn, pgprot_t prot)
 {
 	if (pfn > (PTE_RPN_MASK >> PAGE_SHIFT)) {
 		WARN(1, "remap_4k_pfn called with wrong pfn value\n");
 		return -EINVAL;
 	}
 	return remap_pfn_range(vma, addr, pfn, PAGE_SIZE,
 			       __pgprot(pgprot_val(prot) | H_PAGE_4K_PFN));
 }

 #define PTE_TABLE_SIZE	PTE_FRAG_SIZE
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 #define PMD_TABLE_SIZE	((sizeof(pmd_t) << PMD_INDEX_SIZE) + (sizeof(unsigned long) << PMD_INDEX_SIZE))
 #else
 #define PMD_TABLE_SIZE	(sizeof(pmd_t) << PMD_INDEX_SIZE)
 #endif
 #define PUD_TABLE_SIZE	(sizeof(pud_t) << PUD_INDEX_SIZE)
 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)

 #ifdef CONFIG_HUGETLB_PAGE
 /*
  * We have PGD_INDEX_SIZ = 12 and PTE_INDEX_SIZE = 8, so that we can have
  * 16GB hugepage pte in PGD and 16MB hugepage pte at PMD;
  *
  * Defined in such a way that we can optimize away code block at build time
  * if CONFIG_HUGETLB_PAGE=n.
  */
 static inline int pmd_huge(pmd_t pmd)
 {
 	/*
 	 * leaf pte for huge page
 	 */
 	return !!(pmd_val(pmd) & _PAGE_PTE);
 }

 static inline int pud_huge(pud_t pud)
 {
 	/*
 	 * leaf pte for huge page
 	 */
 	return !!(pud_val(pud) & _PAGE_PTE);
 }

 static inline int pgd_huge(pgd_t pgd)
 {
 	/*
 	 * leaf pte for huge page
 	 */
 	return !!(pgd_val(pgd) & _PAGE_PTE);
 }
 #define pgd_huge pgd_huge

 #ifdef CONFIG_DEBUG_VM
 extern int hugepd_ok(hugepd_t hpd);
 #define is_hugepd(hpd)               (hugepd_ok(hpd))
 #else
 /*
  * With 64k page size, we have hugepage ptes in the pgd and pmd entries. We don't
  * need to setup hugepage directory for them. Our pte and page directory format
  * enable us to have this enabled.
  */
 static inline int hugepd_ok(hugepd_t hpd)
 {
 	return 0;
 }
 #define is_hugepd(pdep)			0
 #endif /* CONFIG_DEBUG_VM */

 #endif /* CONFIG_HUGETLB_PAGE */

 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 extern unsigned long pmd_hugepage_update(struct mm_struct *mm,
 					 unsigned long addr,
 					 pmd_t *pmdp,
 					 unsigned long clr,
 					 unsigned long set);
 static inline char *get_hpte_slot_array(pmd_t *pmdp)
 {
 	/*
 	 * The hpte hindex is stored in the pgtable whose address is in the
 	 * second half of the PMD
 	 *
 	 * Order this load with the test for pmd_trans_huge in the caller
 	 */
 	smp_rmb();
 	return *(char **)(pmdp + PTRS_PER_PMD);


 }
 /*
  * The linux hugepage PMD now include the pmd entries followed by the address
  * to the stashed pgtable_t. The stashed pgtable_t contains the hpte bits.
  * [ 000 | 1 bit secondary | 3 bit hidx | 1 bit valid]. We use one byte per
  * each HPTE entry. With 16MB hugepage and 64K HPTE we need 256 entries and
  * with 4K HPTE we need 4096 entries. Both will fit in a 4K pgtable_t.
  *
  * The top three bits are intentionally left as zero. This memory location
  * are also used as normal page PTE pointers. So if we have any pointers
  * left around while we collapse a hugepage, we need to make sure
  * _PAGE_PRESENT bit of that is zero when we look at them
  */
 static inline unsigned int hpte_valid(unsigned char *hpte_slot_array, int index)
 {
 	return hpte_slot_array[index] & 0x1;
 }

 static inline unsigned int hpte_hash_index(unsigned char *hpte_slot_array,
 					   int index)
 {
 	return hpte_slot_array[index] >> 1;
 }

 static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array,
 					unsigned int index, unsigned int hidx)
 {
 	hpte_slot_array[index] = (hidx << 1) | 0x1;
 }

 /*
  *
  * For core kernel code by design pmd_trans_huge is never run on any hugetlbfs
  * page. The hugetlbfs page table walking and mangling paths are totally
  * separated form the core VM paths and they're differentiated by
  *  VM_HUGETLB being set on vm_flags well before any pmd_trans_huge could run.
  *
  * pmd_trans_huge() is defined as false at build time if
  * CONFIG_TRANSPARENT_HUGEPAGE=n to optimize away code blocks at build
  * time in such case.
  *
  * For ppc64 we need to differntiate from explicit hugepages from THP, because
  * for THP we also track the subpage details at the pmd level. We don't do
  * that for explicit huge pages.
  *
  */
 static inline int pmd_trans_huge(pmd_t pmd)
 {
 	return !!((pmd_val(pmd) & (_PAGE_PTE | H_PAGE_THP_HUGE)) ==
 		  (_PAGE_PTE | H_PAGE_THP_HUGE));
 }

 static inline int pmd_large(pmd_t pmd)
 {
 	return !!(pmd_val(pmd) & _PAGE_PTE);
 }

 static inline pmd_t pmd_mknotpresent(pmd_t pmd)
 {
 	return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
 }

 #define __HAVE_ARCH_PMD_SAME
 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 {
 	return (((pmd_raw(pmd_a) ^ pmd_raw(pmd_b)) & ~cpu_to_be64(_PAGE_HPTEFLAGS)) == 0);
 }

 static inline int __pmdp_test_and_clear_young(struct mm_struct *mm,
 					      unsigned long addr, pmd_t *pmdp)
 {
 	unsigned long old;

 	if ((pmd_val(*pmdp) & (_PAGE_ACCESSED | H_PAGE_HASHPTE)) == 0)
 		return 0;
 	old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED, 0);
 	return ((old & _PAGE_ACCESSED) != 0);
 }

 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
 static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
 				      pmd_t *pmdp)
 {

 	if ((pmd_val(*pmdp) & _PAGE_WRITE) == 0)
 		return;

 	pmd_hugepage_update(mm, addr, pmdp, _PAGE_WRITE, 0);
 }

 #endif /*  CONFIG_TRANSPARENT_HUGEPAGE */
 #endif	/* __ASSEMBLY__ */

 #endif /* _ASM_POWERPC_BOOK3S_64_HASH_64K_H */
	#ifndef _ASM_POWERPC_BOOK3S_64_HASH_64K_H
	#define _ASM_POWERPC_BOOK3S_64_HASH_64K_H

	#define PTE_INDEX_SIZE 8
	#define PMD_INDEX_SIZE 5
	#define PUD_INDEX_SIZE 5
	#define PGD_INDEX_SIZE 12

	#define PTRS_PER_PTE (1 << PTE_INDEX_SIZE)
	#define PTRS_PER_PMD (1 << PMD_INDEX_SIZE)
	#define PTRS_PER_PUD (1 << PUD_INDEX_SIZE)
	#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)

	/* With 4k base page size, hugepage PTEs go at the PMD level */
	#define MIN_HUGEPTE_SHIFT PAGE_SHIFT

	/* PMD_SHIFT determines what a second-level page table entry can map */
	#define PMD_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
	#define PMD_SIZE (1UL << PMD_SHIFT)
	#define PMD_MASK (~(PMD_SIZE-1))

	/* PUD_SHIFT determines what a third-level page table entry can map */
	#define PUD_SHIFT (PMD_SHIFT + PMD_INDEX_SIZE)
	#define PUD_SIZE (1UL << PUD_SHIFT)
	#define PUD_MASK (~(PUD_SIZE-1))

	/* PGDIR_SHIFT determines what a fourth-level page table entry can map */
	#define PGDIR_SHIFT (PUD_SHIFT + PUD_INDEX_SIZE)
	#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
	#define PGDIR_MASK (~(PGDIR_SIZE-1))

	#define H_PAGE_COMBO 0x00001000 /* this is a combo 4k page */
	#define H_PAGE_4K_PFN 0x00002000 /* PFN is for a single 4k page */
	/*
	* We need to differentiate between explicit huge page and THP huge
	* page, since THP huge page also need to track real subpage details
	*/
	#define H_PAGE_THP_HUGE H_PAGE_4K_PFN

	/*
	* Used to track subpage group valid if H_PAGE_COMBO is set
	* This overloads H_PAGE_F_GIX and H_PAGE_F_SECOND
	*/
	#define H_PAGE_COMBO_VALID (H_PAGE_F_GIX \| H_PAGE_F_SECOND)

	/* PTE flags to conserve for HPTE identification */
	#define _PAGE_HPTEFLAGS (H_PAGE_BUSY \| H_PAGE_F_SECOND \| \
	H_PAGE_F_GIX \| H_PAGE_HASHPTE \| H_PAGE_COMBO)
	/*
	* we support 16 fragments per PTE page of 64K size.
	*/
	#define PTE_FRAG_NR 16
	/*
	* We use a 2K PTE page fragment and another 2K for storing
	* real_pte_t hash index
	*/
	#define PTE_FRAG_SIZE_SHIFT 12
	#define PTE_FRAG_SIZE (1UL << PTE_FRAG_SIZE_SHIFT)

	/* Bits to mask out from a PMD to get to the PTE page */
	#define PMD_MASKED_BITS 0xc0000000000000ffUL
	/* Bits to mask out from a PUD to get to the PMD page */
	#define PUD_MASKED_BITS 0xc0000000000000ffUL
	/* Bits to mask out from a PGD to get to the PUD page */
	#define PGD_MASKED_BITS 0xc0000000000000ffUL

	#ifndef __ASSEMBLY__
	#include <asm/errno.h>

	/*
	* With 64K pages on hash table, we have a special PTE format that
	* uses a second "half" of the page table to encode sub-page information
	* in order to deal with 64K made of 4K HW pages. Thus we override the
	* generic accessors and iterators here
	*/
	#define __real_pte __real_pte
	static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep)
	{
	real_pte_t rpte;
	unsigned long *hidxp;

	rpte.pte = pte;
	rpte.hidx = 0;
	if (pte_val(pte) & H_PAGE_COMBO) {
	/*
	* Make sure we order the hidx load against the H_PAGE_COMBO
	* check. The store side ordering is done in __hash_page_4K
	*/
	smp_rmb();
	hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
	rpte.hidx = *hidxp;
	}
	return rpte;
	}

	static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
	{
	if ((pte_val(rpte.pte) & H_PAGE_COMBO))
	return (rpte.hidx >> (index<<2)) & 0xf;
	return (pte_val(rpte.pte) >> H_PAGE_F_GIX_SHIFT) & 0xf;
	}

	#define __rpte_to_pte(r) ((r).pte)
	extern bool __rpte_sub_valid(real_pte_t rpte, unsigned long index);
	/*
	* Trick: we set __end to va + 64k, which happens works for
	* a 16M page as well as we want only one iteration
	*/
	#define pte_iterate_hashed_subpages(rpte, psize, vpn, index, shift) \
	do { \
	unsigned long __end = vpn + (1UL << (PAGE_SHIFT - VPN_SHIFT)); \
	unsigned __split = (psize == MMU_PAGE_4K \|\| \
	psize == MMU_PAGE_64K_AP); \
	shift = mmu_psize_defs[psize].shift; \
	for (index = 0; vpn < __end; index++, \
	vpn += (1L << (shift - VPN_SHIFT))) { \
	if (!__split \|\| __rpte_sub_valid(rpte, index)) \
	do {

	#define pte_iterate_hashed_end() } while(0); } } while(0)

	#define pte_pagesize_index(mm, addr, pte) \
	(((pte) & H_PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K)

	extern int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
	unsigned long pfn, unsigned long size, pgprot_t);
	static inline int remap_4k_pfn(struct vm_area_struct *vma, unsigned long addr,
	unsigned long pfn, pgprot_t prot)
	{
	if (pfn > (PTE_RPN_MASK >> PAGE_SHIFT)) {
	WARN(1, "remap_4k_pfn called with wrong pfn value\n");
	return -EINVAL;
	}
	return remap_pfn_range(vma, addr, pfn, PAGE_SIZE,
	__pgprot(pgprot_val(prot) \| H_PAGE_4K_PFN));
	}

	#define PTE_TABLE_SIZE PTE_FRAG_SIZE
	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	#define PMD_TABLE_SIZE ((sizeof(pmd_t) << PMD_INDEX_SIZE) + (sizeof(unsigned long) << PMD_INDEX_SIZE))
	#else
	#define PMD_TABLE_SIZE (sizeof(pmd_t) << PMD_INDEX_SIZE)
	#endif
	#define PUD_TABLE_SIZE (sizeof(pud_t) << PUD_INDEX_SIZE)
	#define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE)

	#ifdef CONFIG_HUGETLB_PAGE
	/*
	* We have PGD_INDEX_SIZ = 12 and PTE_INDEX_SIZE = 8, so that we can have
	* 16GB hugepage pte in PGD and 16MB hugepage pte at PMD;
	*
	* Defined in such a way that we can optimize away code block at build time
	* if CONFIG_HUGETLB_PAGE=n.
	*/
	static inline int pmd_huge(pmd_t pmd)
	{
	/*
	* leaf pte for huge page
	*/
	return !!(pmd_val(pmd) & _PAGE_PTE);
	}

	static inline int pud_huge(pud_t pud)
	{
	/*
	* leaf pte for huge page
	*/
	return !!(pud_val(pud) & _PAGE_PTE);
	}

	static inline int pgd_huge(pgd_t pgd)
	{
	/*
	* leaf pte for huge page
	*/
	return !!(pgd_val(pgd) & _PAGE_PTE);
	}
	#define pgd_huge pgd_huge

	#ifdef CONFIG_DEBUG_VM
	extern int hugepd_ok(hugepd_t hpd);
	#define is_hugepd(hpd) (hugepd_ok(hpd))
	#else
	/*
	* With 64k page size, we have hugepage ptes in the pgd and pmd entries. We don't
	* need to setup hugepage directory for them. Our pte and page directory format
	* enable us to have this enabled.
	*/
	static inline int hugepd_ok(hugepd_t hpd)
	{
	return 0;
	}
	#define is_hugepd(pdep) 0
	#endif /* CONFIG_DEBUG_VM */

	#endif /* CONFIG_HUGETLB_PAGE */

	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	extern unsigned long pmd_hugepage_update(struct mm_struct *mm,
	unsigned long addr,
	pmd_t *pmdp,
	unsigned long clr,
	unsigned long set);
	static inline char get_hpte_slot_array(pmd_t pmdp)
	{
	/*
	* The hpte hindex is stored in the pgtable whose address is in the
	* second half of the PMD
	*
	* Order this load with the test for pmd_trans_huge in the caller
	*/
	smp_rmb();
	return (char *)(pmdp + PTRS_PER_PMD);


	}
	/*
	* The linux hugepage PMD now include the pmd entries followed by the address
	* to the stashed pgtable_t. The stashed pgtable_t contains the hpte bits.
	* [ 000 \| 1 bit secondary \| 3 bit hidx \| 1 bit valid]. We use one byte per
	* each HPTE entry. With 16MB hugepage and 64K HPTE we need 256 entries and
	* with 4K HPTE we need 4096 entries. Both will fit in a 4K pgtable_t.
	*
	* The top three bits are intentionally left as zero. This memory location
	* are also used as normal page PTE pointers. So if we have any pointers
	* left around while we collapse a hugepage, we need to make sure
	* _PAGE_PRESENT bit of that is zero when we look at them
	*/
	static inline unsigned int hpte_valid(unsigned char *hpte_slot_array, int index)
	{
	return hpte_slot_array[index] & 0x1;
	}

	static inline unsigned int hpte_hash_index(unsigned char *hpte_slot_array,
	int index)
	{
	return hpte_slot_array[index] >> 1;
	}

	static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array,
	unsigned int index, unsigned int hidx)
	{
	hpte_slot_array[index] = (hidx << 1) \| 0x1;
	}

	/*
	*
	* For core kernel code by design pmd_trans_huge is never run on any hugetlbfs
	* page. The hugetlbfs page table walking and mangling paths are totally
	* separated form the core VM paths and they're differentiated by
	* VM_HUGETLB being set on vm_flags well before any pmd_trans_huge could run.
	*
	* pmd_trans_huge() is defined as false at build time if
	* CONFIG_TRANSPARENT_HUGEPAGE=n to optimize away code blocks at build
	* time in such case.
	*
	* For ppc64 we need to differntiate from explicit hugepages from THP, because
	* for THP we also track the subpage details at the pmd level. We don't do
	* that for explicit huge pages.
	*
	*/
	static inline int pmd_trans_huge(pmd_t pmd)
	{
	return !!((pmd_val(pmd) & (_PAGE_PTE \| H_PAGE_THP_HUGE)) ==
	(_PAGE_PTE \| H_PAGE_THP_HUGE));
	}

	static inline int pmd_large(pmd_t pmd)
	{
	return !!(pmd_val(pmd) & _PAGE_PTE);
	}

	static inline pmd_t pmd_mknotpresent(pmd_t pmd)
	{
	return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
	}

	#define __HAVE_ARCH_PMD_SAME
	static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
	{
	return (((pmd_raw(pmd_a) ^ pmd_raw(pmd_b)) & ~cpu_to_be64(_PAGE_HPTEFLAGS)) == 0);
	}

	static inline int __pmdp_test_and_clear_young(struct mm_struct *mm,
	unsigned long addr, pmd_t *pmdp)
	{
	unsigned long old;

	if ((pmd_val(*pmdp) & (_PAGE_ACCESSED \| H_PAGE_HASHPTE)) == 0)
	return 0;
	old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED, 0);
	return ((old & _PAGE_ACCESSED) != 0);
	}

	#define __HAVE_ARCH_PMDP_SET_WRPROTECT
	static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
	pmd_t *pmdp)
	{

	if ((pmd_val(*pmdp) & _PAGE_WRITE) == 0)
	return;

	pmd_hugepage_update(mm, addr, pmdp, _PAGE_WRITE, 0);
	}

	#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
	#endif /* __ASSEMBLY__ */

	#endif /* _ASM_POWERPC_BOOK3S_64_HASH_64K_H */