mm: clarify that the function operates on hugepage pte

We have confusing functions to clear pmd, pmd_clear_* and pmd_clear.  Add
_huge_ to pmdp_clear functions so that we are clear that they operate on
hugepage pte.

We don't bother about other functions like pmdp_set_wrprotect,
pmdp_clear_flush_young, because they operate on PTE bits and hence
indicate they are operating on hugepage ptes

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index f21dc5f..6b674e0 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -119,15 +119,15 @@
 }
 #endif
 
-#ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
+#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
-		       pmd_t *pmdp)
+pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
+			    pmd_t *pmdp)
 {
 	pmd_t pmd;
 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 	VM_BUG_ON(!pmd_trans_huge(*pmdp));
-	pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
+	pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
 	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 	return pmd;
 }
@@ -205,11 +205,15 @@
 pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
 			  pmd_t *pmdp)
 {
+	/*
+	 * pmd and hugepage pte format are same. So we could
+	 * use the same function.
+	 */
 	pmd_t pmd;
 
 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 	VM_BUG_ON(pmd_trans_huge(*pmdp));
-	pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
+	pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
 	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 	return pmd;
 }