hugetlb: introduce generic version of set_huge_pte_at()

arm, ia64, mips, powerpc, sh, x86 architectures use the same version of
set_huge_pte_at, so move this generic implementation into
asm-generic/hugetlb.h.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexandre Ghiti <[email protected]>
Reviewed-by: Luiz Capitulino <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
Tested-by: Helge Deller <[email protected]>			[parisc]
Acked-by: Catalin Marinas <[email protected]>	[arm64]
Acked-by: Paul Burton <[email protected]>		[MIPS]
Acked-by: Ingo Molnar <[email protected]>		[x86]
Cc: Arnd Bergmann <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James E.J. Bottomley <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index c697ca9..ee010b7 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -47,8 +47,14 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 {
 	free_pgd_range(tlb, addr, end, floor, ceiling);
 }
+#endif
 
-
+#ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
+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);
+}
 #endif
 
 #endif /* _ASM_GENERIC_HUGETLB_H */