Commit b113da65 authored by David Miller's avatar David Miller Committed by Linus Torvalds
Browse files

mm: Add and use update_mmu_cache_pmd() in transparent huge page code. 



The transparent huge page code passes a PMD pointer in as the third
argument of update_mmu_cache(), which expects a PTE pointer.

This never got noticed because X86 implements update_mmu_cache() as a
macro and thus we don't get any type checking, and X86 is the only
architecture which supports transparent huge pages currently.

Before other architectures can support transparent huge pages properly we
need to add a new interface which will take a PMD pointer as the third
argument rather than a PTE pointer.

[akpm@linux-foundation.org: implement update_mm_cache_pmd() for s390]
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent dbc9fdf0

arch/s390/include/asm/pgtable.h

+1 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ extern void fault_init(void); 
 * tables contain all the necessary information.

 */

#define update_mmu_cache(vma, address, ptep)     do { } while (0)

#define update_mmu_cache_pmd(vma, address, ptep) do { } while (0)



/*

 * ZERO_PAGE is a global shared page that is always zero; used

arch/x86/include/asm/pgtable_32.h

+1 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ do { \ 
 * tables contain all the necessary information.

 */

#define update_mmu_cache(vma, address, ptep) do { } while (0)

#define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)



#endif /* !__ASSEMBLY__ */

arch/x86/include/asm/pgtable_64.h

+1 −0
Original line number Diff line number Diff line
@@ -143,6 +143,7 @@ static inline int pgd_large(pgd_t pgd) { return 0; } 
#define pte_unmap(pte) ((void)(pte))/* NOP */



#define update_mmu_cache(vma, address, ptep) do { } while (0)

#define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)



/* Encode and de-code a swap entry */

#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE

mm/huge_memory.c

+3 −3
Original line number Diff line number Diff line
@@ -900,7 +900,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, 
		entry = pmd_mkyoung(orig_pmd);

		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);

		if (pmdp_set_access_flags(vma, haddr, pmd, entry,  1))

			update_mmu_cache(vma, address, pmd);

			update_mmu_cache_pmd(vma, address, pmd);

		ret |= VM_FAULT_WRITE;

		goto out_unlock;

	}
@@ -956,7 +956,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, 
		pmdp_clear_flush(vma, haddr, pmd);

		page_add_new_anon_rmap(new_page, vma, haddr);

		set_pmd_at(mm, haddr, pmd, entry);

		update_mmu_cache(vma, address, pmd);

		update_mmu_cache_pmd(vma, address, pmd);

		page_remove_rmap(page);

		put_page(page);

		ret |= VM_FAULT_WRITE;
@@ -2041,7 +2041,7 @@ static void collapse_huge_page(struct mm_struct *mm, 
	BUG_ON(!pmd_none(*pmd));

	page_add_new_anon_rmap(new_page, vma, address);

	set_pmd_at(mm, address, pmd, _pmd);

	update_mmu_cache(vma, address, pmd);

	update_mmu_cache_pmd(vma, address, pmd);

	pgtable_trans_huge_deposit(mm, pgtable);

	spin_unlock(&mm->page_table_lock);

CRA Git | Maintained and supported by SUSTech CRA and CCSE