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arch: fix has_transparent_hugepage()

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I've just discovered that the useful-sounding has_transparent_hugepage()
is actually an architecture-dependent minefield: on some arches it only
builds if CONFIG_TRANSPARENT_HUGEPAGE=y, on others it's also there when
not, but on some of those (arm and arm64) it then gives the wrong
answer; and on mips alone it's marked __init, which would crash if
called later (but so far it has not been called later).

Straighten this out: make it available to all configs, with a sensible
default in asm-generic/pgtable.h, removing its definitions from those
arches (arc, arm, arm64, sparc, tile) which are served by the default,
adding #define has_transparent_hugepage has_transparent_hugepage to
those (mips, powerpc, s390, x86) which need to override the default at
runtime, and removing the __init from mips (but maybe that kind of code
should be avoided after init: set a static variable the first time it's
called).

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Ning Qu <quning@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>		[arch/arc]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>	[arch/s390]
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Hugh Dickins 2016-05-19 17:13:00 -07:00 committed by Linus Torvalds
parent 1d069b7dd5
commit fd8cfd3000
12 changed files with 23 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arc/include/asm/hugepage.h
View File

@ -61,8 +61,6 @@ static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd);
#define has_transparent_hugepage() 1
/* Generic variants assume pgtable_t is struct page *, hence need for these */
#define __HAVE_ARCH_PGTABLE_DEPOSIT
extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,

5
arch/arm/include/asm/pgtable-3level.h
View File

@ -281,11 +281,6 @@ static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
flush_pmd_entry(pmdp);
}
static inline int has_transparent_hugepage(void)
{
return 1;
}
#endif /* __ASSEMBLY__ */
#endif /* _ASM_PGTABLE_3LEVEL_H */

5
arch/arm64/include/asm/pgtable.h
View File

@ -314,11 +314,6 @@ static inline int pmd_protnone(pmd_t pmd)
#define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
static inline int has_transparent_hugepage(void)
{
return 1;
}
#define __pgprot_modify(prot,mask,bits) \
__pgprot((pgprot_val(prot) & ~(mask)) | (bits))

1
arch/mips/include/asm/pgtable.h
View File

@ -468,6 +468,7 @@ static inline int io_remap_pfn_range(struct vm_area_struct *vma,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define has_transparent_hugepage has_transparent_hugepage
extern int has_transparent_hugepage(void);
static inline int pmd_trans_huge(pmd_t pmd)

21
arch/mips/mm/tlb-r4k.c
View File

@ -400,19 +400,20 @@ void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
int __init has_transparent_hugepage(void)
int has_transparent_hugepage(void)
{
unsigned int mask;
unsigned long flags;
static unsigned int mask = -1;
local_irq_save(flags);
write_c0_pagemask(PM_HUGE_MASK);
back_to_back_c0_hazard();
mask = read_c0_pagemask();
write_c0_pagemask(PM_DEFAULT_MASK);
local_irq_restore(flags);
if (mask == -1) { /* first call comes during __init */
unsigned long flags;
local_irq_save(flags);
write_c0_pagemask(PM_HUGE_MASK);
back_to_back_c0_hazard();
mask = read_c0_pagemask();
write_c0_pagemask(PM_DEFAULT_MASK);
local_irq_restore(flags);
}
return mask == PM_HUGE_MASK;
}

1
arch/powerpc/include/asm/book3s/64/pgtable.h
View File

@ -219,6 +219,7 @@ extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd);
extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd);
#define has_transparent_hugepage has_transparent_hugepage
extern int has_transparent_hugepage(void);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

1
arch/powerpc/include/asm/pgtable.h
View File

@ -65,7 +65,6 @@ extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
struct page **pages, int *nr);
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
#define pmd_large(pmd) 0
#define has_transparent_hugepage() 0
#endif
pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
bool *is_thp, unsigned *shift);

1
arch/s390/include/asm/pgtable.h
View File

@ -1223,6 +1223,7 @@ static inline int pmd_trans_huge(pmd_t pmd)
return pmd_val(pmd) & _SEGMENT_ENTRY_LARGE;
}
#define has_transparent_hugepage has_transparent_hugepage
static inline int has_transparent_hugepage(void)
{
return MACHINE_HAS_HPAGE ? 1 : 0;

2
arch/sparc/include/asm/pgtable_64.h
View File

@ -681,8 +681,6 @@ static inline unsigned long pmd_trans_huge(pmd_t pmd)
return pte_val(pte) & _PAGE_PMD_HUGE;
}
#define has_transparent_hugepage() 1
static inline pmd_t pmd_mkold(pmd_t pmd)
{
pte_t pte = __pte(pmd_val(pmd));

1
arch/tile/include/asm/pgtable.h
View File

@ -487,7 +487,6 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define has_transparent_hugepage() 1
#define pmd_trans_huge pmd_huge_page
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

1
arch/x86/include/asm/pgtable.h
View File

@ -181,6 +181,7 @@ static inline int pmd_trans_huge(pmd_t pmd)
return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
}
#define has_transparent_hugepage has_transparent_hugepage
static inline int has_transparent_hugepage(void)
{
return boot_cpu_has(X86_FEATURE_PSE);

8
include/asm-generic/pgtable.h
View File

@ -806,4 +806,12 @@ static inline int pmd_clear_huge(pmd_t *pmd)
#define io_remap_pfn_range remap_pfn_range
#endif
#ifndef has_transparent_hugepage
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define has_transparent_hugepage() 1
#else
#define has_transparent_hugepage() 0
#endif
#endif
#endif /* _ASM_GENERIC_PGTABLE_H */