powerpc/mm: define get_slice_psize() all the time

get_slice_psize() can be defined regardless of CONFIG_PPC_MM_SLICES
to avoid ifdefs
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/slice.h

@@ -36,6 +36,11 @@ void slice_setup_new_exec(void);
 
 static inline void slice_init_new_context_exec(struct mm_struct *mm) {}
 
+static inline unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
+{
+	return 0;
+}
+
 #endif /* CONFIG_PPC_MM_SLICES */
 
 #endif /* __ASSEMBLY__ */

arch/powerpc/mm/hugetlbpage.c

@@ -578,14 +578,12 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 
 unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
 {
-#ifdef CONFIG_PPC_MM_SLICES
 	/* With radix we don't use slice, so derive it from vma*/
-	if (!radix_enabled()) {
+	if (IS_ENABLED(CONFIG_PPC_MM_SLICES) && !radix_enabled()) {
 		unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
 
 		return 1UL << mmu_psize_to_shift(psize);
 	}
-#endif
 	return vma_kernel_pagesize(vma);
 }