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: David 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 6 insertions, 3 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index ed14fc2db6e0..979fe3dc0788 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -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
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index 0c92113c4cb6..8faa215a503e 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -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__ */
 
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 8251be02301e..47356f9df82e 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -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
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 3a8d6b7d95db..68a3c93036f6 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -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);