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mm,thp: reduce ifdef'ery for THP in generic code
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- pgtable-generic.c: Fold individual #ifdef for each helper into a top
  level #ifdef. Makes code more readable

- Converted the stub helpers for !THP to BUILD_BUG() vs. runtime BUG()

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20151009133450.GA8597@node
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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@vineetgarc
vineetgarc committed Oct 17, 2015
1 parent 52585bc commit bd5e88a
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Showing 2 changed files with 33 additions and 28 deletions.
37 changes: 30 additions & 7 deletions include/asm-generic/pgtable.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,9 +30,19 @@ extern int ptep_set_access_flags(struct vm_area_struct *vma,
#endif

#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern int pmdp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp,
pmd_t entry, int dirty);
#else
static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp,
pmd_t entry, int dirty)
{
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
Expand Down Expand Up @@ -64,12 +74,12 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
return r;
}
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#else
static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address,
pmd_t *pmdp)
{
BUG();
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
Expand All @@ -81,8 +91,21 @@ int ptep_clear_flush_young(struct vm_area_struct *vma,
#endif

#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);
#else
/*
* Despite relevant to THP only, this API is called from generic rmap code
* under PageTransHuge(), hence needs a dummy implementation for !THP
*/
static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
Expand Down Expand Up @@ -175,11 +198,11 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
pmd_t old_pmd = *pmdp;
set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
}
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#else
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
unsigned long address, pmd_t *pmdp)
{
BUG();
BUILD_BUG();
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
Expand Down Expand Up @@ -248,7 +271,7 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
{
BUG();
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
Expand Down
24 changes: 3 additions & 21 deletions mm/pgtable-generic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -82,23 +82,20 @@ pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
}
#endif

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
int pmdp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp,
pmd_t entry, int dirty)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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);
}
return changed;
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
BUG();
return 0;
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
}
#endif

Expand All @@ -107,11 +104,7 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
int young;
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
#else
BUG();
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
young = pmdp_test_and_clear_young(vma, address, pmdp);
if (young)
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
Expand All @@ -120,7 +113,6 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma,
#endif

#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
Expand All @@ -131,11 +123,9 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
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
void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
Expand All @@ -145,11 +135,9 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
/* tlb flush only to serialize against gup-fast */
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable)
{
Expand All @@ -162,11 +150,9 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru);
pmd_huge_pte(mm, pmdp) = pgtable;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/* no "address" argument so destroys page coloring of some arch */
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
{
Expand All @@ -185,23 +171,19 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
}
return pgtable;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PMDP_INVALIDATE
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t entry = *pmdp;
set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(entry));
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef pmdp_collapse_flush
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
Expand All @@ -217,5 +199,5 @@ pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
return pmd;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

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