Merge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu

Pull percpu fixes from Dennis Zhou:
 "Two small things for v4.20.

  The first fixes a clang uninitialized variable warning for arm64 in
  the default path calls BUILD_BUG(). The second removes an unnecessary
  unlikely() in a WARN_ON() use"

* 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  arm64: percpu: Initialize ret in the default case
  mm: percpu: remove unnecessary unlikely()

arch/arm64/include/asm/percpu.h

@@ -96,6 +96,7 @@ static inline unsigned long __percpu_##op(void *ptr,			\
 		: [val] "Ir" (val));					\
 		break;							\
 	default:							\
+		ret = 0;						\
 		BUILD_BUG();						\
 	}								\
 									\
@@ -125,6 +126,7 @@ static inline unsigned long __percpu_read(void *ptr, int size)
 		ret = READ_ONCE(*(u64 *)ptr);
 		break;
 	default:
+		ret = 0;
 		BUILD_BUG();
 	}
 
@@ -194,6 +196,7 @@ static inline unsigned long __percpu_xchg(void *ptr, unsigned long val,
 		: [val] "r" (val));
 		break;
 	default:
+		ret = 0;
 		BUILD_BUG();
 	}
 

mm/percpu.c

@@ -2591,7 +2591,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size,
 	BUG_ON(ai->nr_groups != 1);
 	upa = ai->alloc_size/ai->unit_size;
 	nr_g0_units = roundup(num_possible_cpus(), upa);
-	if (unlikely(WARN_ON(ai->groups[0].nr_units != nr_g0_units))) {
+	if (WARN_ON(ai->groups[0].nr_units != nr_g0_units)) {
 		pcpu_free_alloc_info(ai);
 		return -EINVAL;
 	}