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thp: add x86 32bit support
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Add support for transparent hugepages to x86 32bit.

Share the same VM_ bitflag for VM_MAPPED_COPY.  mm/nommu.c will never
support transparent hugepages.

Signed-off-by: Johannes Weiner <[email protected]>
Signed-off-by: Andrea Arcangeli <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@hnaz @torvalds
hnaz authored and torvalds committed Jan 14, 2011
1 parent 5f24ce5 commit f2d6bfe
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Showing 7 changed files with 156 additions and 115 deletions.
9 changes: 9 additions & 0 deletions arch/x86/include/asm/pgtable-2level.h
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,15 @@ static inline pte_t native_ptep_get_and_clear(pte_t *xp)
#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
#endif

#ifdef CONFIG_SMP
static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
{
return __pmd(xchg((pmdval_t *)xp, 0));
}
#else
#define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
#endif

/*
* Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE and _PAGE_BIT_PROTNONE are taken,
* split up the 29 bits of offset into this range:
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23 changes: 23 additions & 0 deletions arch/x86/include/asm/pgtable-3level.h
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Original file line number Diff line number Diff line change
Expand Up @@ -104,6 +104,29 @@ static inline pte_t native_ptep_get_and_clear(pte_t *ptep)
#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
#endif

#ifdef CONFIG_SMP
union split_pmd {
struct {
u32 pmd_low;
u32 pmd_high;
};
pmd_t pmd;
};
static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp)
{
union split_pmd res, *orig = (union split_pmd *)pmdp;

/* xchg acts as a barrier before setting of the high bits */
res.pmd_low = xchg(&orig->pmd_low, 0);
res.pmd_high = orig->pmd_high;
orig->pmd_high = 0;

return res.pmd;
}
#else
#define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
#endif

/*
* Bits 0, 6 and 7 are taken in the low part of the pte,
* put the 32 bits of offset into the high part.
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117 changes: 117 additions & 0 deletions arch/x86/include/asm/pgtable.h
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Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,11 @@ static inline int pte_young(pte_t pte)
return pte_flags(pte) & _PAGE_ACCESSED;
}

static inline int pmd_young(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_ACCESSED;
}

static inline int pte_write(pte_t pte)
{
return pte_flags(pte) & _PAGE_RW;
Expand Down Expand Up @@ -145,6 +150,18 @@ static inline int pmd_large(pmd_t pte)
(_PAGE_PSE | _PAGE_PRESENT);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_trans_splitting(pmd_t pmd)
{
return pmd_val(pmd) & _PAGE_SPLITTING;
}

static inline int pmd_trans_huge(pmd_t pmd)
{
return pmd_val(pmd) & _PAGE_PSE;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

static inline pte_t pte_set_flags(pte_t pte, pteval_t set)
{
pteval_t v = native_pte_val(pte);
Expand Down Expand Up @@ -219,6 +236,55 @@ static inline pte_t pte_mkspecial(pte_t pte)
return pte_set_flags(pte, _PAGE_SPECIAL);
}

static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set)
{
pmdval_t v = native_pmd_val(pmd);

return __pmd(v | set);
}

static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear)
{
pmdval_t v = native_pmd_val(pmd);

return __pmd(v & ~clear);
}

static inline pmd_t pmd_mkold(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_ACCESSED);
}

static inline pmd_t pmd_wrprotect(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_RW);
}

static inline pmd_t pmd_mkdirty(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_DIRTY);
}

static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_PSE);
}

static inline pmd_t pmd_mkyoung(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_ACCESSED);
}

static inline pmd_t pmd_mkwrite(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_RW);
}

static inline pmd_t pmd_mknotpresent(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_PRESENT);
}

/*
* Mask out unsupported bits in a present pgprot. Non-present pgprots
* can use those bits for other purposes, so leave them be.
Expand Down Expand Up @@ -527,6 +593,14 @@ static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)
return res;
}

static inline pmd_t native_local_pmdp_get_and_clear(pmd_t *pmdp)
{
pmd_t res = *pmdp;

native_pmd_clear(pmdp);
return res;
}

static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep , pte_t pte)
{
Expand Down Expand Up @@ -616,6 +690,49 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm,

#define flush_tlb_fix_spurious_fault(vma, address)

#define mk_pmd(page, pgprot) pfn_pmd(page_to_pfn(page), (pgprot))

#define __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);

#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
extern int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp);

#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);


#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
extern void pmdp_splitting_flush(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp);

#define __HAVE_ARCH_PMD_WRITE
static inline int pmd_write(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_RW;
}

#define __HAVE_ARCH_PMDP_GET_AND_CLEAR
static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp)
{
pmd_t pmd = native_pmdp_get_and_clear(pmdp);
pmd_update(mm, addr, pmdp);
return pmd;
}

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

/*
* clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
*
Expand Down
109 changes: 0 additions & 109 deletions arch/x86/include/asm/pgtable_64.h
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Original file line number Diff line number Diff line change
Expand Up @@ -182,115 +182,6 @@ extern void cleanup_highmap(void);

#define __HAVE_ARCH_PTE_SAME

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_trans_splitting(pmd_t pmd)
{
return pmd_val(pmd) & _PAGE_SPLITTING;
}

static inline int pmd_trans_huge(pmd_t pmd)
{
return pmd_val(pmd) & _PAGE_PSE;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#define mk_pmd(page, pgprot) pfn_pmd(page_to_pfn(page), (pgprot))

#define __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);

#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
extern int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp);

#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);


#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
extern void pmdp_splitting_flush(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp);

#define __HAVE_ARCH_PMD_WRITE
static inline int pmd_write(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_RW;
}

#define __HAVE_ARCH_PMDP_GET_AND_CLEAR
static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp)
{
pmd_t pmd = native_pmdp_get_and_clear(pmdp);
pmd_update(mm, addr, pmdp);
return pmd;
}

#define __HAVE_ARCH_PMDP_SET_WRPROTECT
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp)
{
clear_bit(_PAGE_BIT_RW, (unsigned long *)&pmdp->pmd);
pmd_update(mm, addr, pmdp);
}

static inline int pmd_young(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_ACCESSED;
}

static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set)
{
pmdval_t v = native_pmd_val(pmd);

return native_make_pmd(v | set);
}

static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear)
{
pmdval_t v = native_pmd_val(pmd);

return native_make_pmd(v & ~clear);
}

static inline pmd_t pmd_mkold(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_ACCESSED);
}

static inline pmd_t pmd_wrprotect(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_RW);
}

static inline pmd_t pmd_mkdirty(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_DIRTY);
}

static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_PSE);
}

static inline pmd_t pmd_mkyoung(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_ACCESSED);
}

static inline pmd_t pmd_mkwrite(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_RW);
}

static inline pmd_t pmd_mknotpresent(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_PRESENT);
}

#endif /* !__ASSEMBLY__ */

#endif /* _ASM_X86_PGTABLE_64_H */
4 changes: 2 additions & 2 deletions arch/x86/mm/pgtable.c
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Original file line number Diff line number Diff line change
Expand Up @@ -362,7 +362,7 @@ int pmdp_test_and_clear_young(struct vm_area_struct *vma,

if (pmd_young(*pmdp))
ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
(unsigned long *) &pmdp->pmd);
(unsigned long *)pmdp);

if (ret)
pmd_update(vma->vm_mm, addr, pmdp);
Expand Down Expand Up @@ -404,7 +404,7 @@ void pmdp_splitting_flush(struct vm_area_struct *vma,
int set;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
set = !test_and_set_bit(_PAGE_BIT_SPLITTING,
(unsigned long *)&pmdp->pmd);
(unsigned long *)pmdp);
if (set) {
pmd_update(vma->vm_mm, address, pmdp);
/* need tlb flush only to serialize against gup-fast */
Expand Down
7 changes: 4 additions & 3 deletions include/linux/mm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -102,7 +102,11 @@ extern unsigned int kobjsize(const void *objp);
#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
#define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */
#else
#define VM_HUGEPAGE 0x01000000 /* MADV_HUGEPAGE marked this vma */
#endif
#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */
#define VM_ALWAYSDUMP 0x04000000 /* Always include in core dumps */

Expand All @@ -111,9 +115,6 @@ extern unsigned int kobjsize(const void *objp);
#define VM_SAO 0x20000000 /* Strong Access Ordering (powerpc) */
#define VM_PFN_AT_MMAP 0x40000000 /* PFNMAP vma that is fully mapped at mmap time */
#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */
#if BITS_PER_LONG > 32
#define VM_HUGEPAGE 0x100000000UL /* MADV_HUGEPAGE marked this vma */
#endif

/* Bits set in the VMA until the stack is in its final location */
#define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ)
Expand Down
2 changes: 1 addition & 1 deletion mm/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -304,7 +304,7 @@ config NOMMU_INITIAL_TRIM_EXCESS

config TRANSPARENT_HUGEPAGE
bool "Transparent Hugepage Support" if EMBEDDED
depends on X86_64 && MMU
depends on X86 && MMU
default y
help
Transparent Hugepages allows the kernel to use huge pages and
Expand Down

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