linux/arch/sh/include/asm/hugetlb.h
Will Deacon 5d3a551c28 mm: hugetlb: add arch hook for clearing page flags before entering pool
The core page allocator ensures that page flags are zeroed when freeing
pages via free_pages_check.  A number of architectures (ARM, PPC, MIPS)
rely on this property to treat new pages as dirty with respect to the data
cache and perform the appropriate flushing before mapping the pages into
userspace.

This can lead to cache synchronisation problems when using hugepages,
since the allocator keeps its own pool of pages above the usual page
allocator and does not reset the page flags when freeing a page into the
pool.

This patch adds a new architecture hook, arch_clear_hugepage_flags, so
that architectures which rely on the page flags being in a particular
state for fresh allocations can adjust the flags accordingly when a page
is freed into the pool.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:24 +09:00

99 lines
2.1 KiB
C

#ifndef _ASM_SH_HUGETLB_H
#define _ASM_SH_HUGETLB_H
#include <asm/cacheflush.h>
#include <asm/page.h>
static inline int is_hugepage_only_range(struct mm_struct *mm,
unsigned long addr,
unsigned long len) {
return 0;
}
/*
* If the arch doesn't supply something else, assume that hugepage
* size aligned regions are ok without further preparation.
*/
static inline int prepare_hugepage_range(struct file *file,
unsigned long addr, unsigned long len)
{
if (len & ~HPAGE_MASK)
return -EINVAL;
if (addr & ~HPAGE_MASK)
return -EINVAL;
return 0;
}
static inline void hugetlb_prefault_arch_hook(struct mm_struct *mm) {
}
static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor,
unsigned long ceiling)
{
free_pgd_range(tlb, addr, end, floor, ceiling);
}
static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
set_pte_at(mm, addr, ptep, pte);
}
static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
return ptep_get_and_clear(mm, addr, ptep);
}
static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
}
static inline int huge_pte_none(pte_t pte)
{
return pte_none(pte);
}
static inline pte_t huge_pte_wrprotect(pte_t pte)
{
return pte_wrprotect(pte);
}
static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
ptep_set_wrprotect(mm, addr, ptep);
}
static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t pte, int dirty)
{
return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
}
static inline pte_t huge_ptep_get(pte_t *ptep)
{
return *ptep;
}
static inline int arch_prepare_hugepage(struct page *page)
{
return 0;
}
static inline void arch_release_hugepage(struct page *page)
{
}
static inline void arch_clear_hugepage_flags(struct page *page)
{
clear_bit(PG_dcache_clean, &page->flags);
}
#endif /* _ASM_SH_HUGETLB_H */