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Commit b3697c02 authored by Andrea Arcangeli's avatar Andrea Arcangeli Committed by Linus Torvalds
Browse files

fix non-x86 build failure in pmdp_get_and_clear 



pmdp_get_and_clear/pmdp_clear_flush/pmdp_splitting_flush were trapped as
BUG() and they were defined only to diminish the risk of build issues on
not-x86 archs and to be consistent with the generic pte methods previously
defined in include/asm-generic/pgtable.h.

But they are causing more trouble than they were supposed to solve, so
it's simpler not to define them when THP is off.

This is also correcting the export of pmdp_splitting_flush which is
currently unused (x86 isn't using the generic implementation in
mm/pgtable-generic.c and no other arch needs that [yet]).

Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7e3d0eb0

include/asm-generic/pgtable.h

+3 −11
Original line number Diff line number Diff line
@@ -87,14 +87,6 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, 
	pmd_clear(mm, address, pmdp);

	return pmd;

})

#else /* CONFIG_TRANSPARENT_HUGEPAGE */

static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,

				       unsigned long address,

				       pmd_t *pmdp)

{

	BUG();

	return __pmd(0);

}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#endif
@@ -163,7 +155,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, 
#endif



#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH

extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma,

extern pmd_t pmdp_splitting_flush(struct vm_area_struct *vma,

				  unsigned long address,

				  pmd_t *pmdp);

#endif

mm/pgtable-generic.c

+4 −7
Original line number Diff line number Diff line
@@ -92,32 +92,29 @@ pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, 
#endif



#ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,

		       pmd_t *pmdp)

{

	pmd_t pmd;

#ifndef CONFIG_TRANSPARENT_HUGEPAGE

	BUG();

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

	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);

	return pmd;

}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#endif



#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

pmd_t pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,

			   pmd_t *pmdp)

{

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	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 */

	BUG();

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#endif