mm: remove gcc workaround

Minimum gcc version is 3.2 now.  However, with likely profiling, even
modern gcc versions cannot always eliminate the call.

Replace the placeholder functions with the more conventional empty static
inlines, which should be optimal for everyone.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/mm.h

@@ -850,8 +850,26 @@ static inline int vma_wants_writenotify(struct vm_area_struct *vma)
 
 extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));
 
+#ifdef __PAGETABLE_PUD_FOLDED
+static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
+						unsigned long address)
+{
+	return 0;
+}
+#else
 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
+#endif
+
+#ifdef __PAGETABLE_PMD_FOLDED
+static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
+						unsigned long address)
+{
+	return 0;
+}
+#else
 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
+#endif
+
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
 

mm/memory.c

@@ -2633,12 +2633,6 @@ int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
 	spin_unlock(&mm->page_table_lock);
 	return 0;
 }
-#else
-/* Workaround for gcc 2.96 */
-int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
-{
-	return 0;
-}
 #endif /* __PAGETABLE_PUD_FOLDED */
 
 #ifndef __PAGETABLE_PMD_FOLDED
@@ -2667,12 +2661,6 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 	spin_unlock(&mm->page_table_lock);
 	return 0;
 }
-#else
-/* Workaround for gcc 2.96 */
-int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
-{
-	return 0;
-}
 #endif /* __PAGETABLE_PMD_FOLDED */
 
 int make_pages_present(unsigned long addr, unsigned long end)