arm64: atomics: fix use of acquire + release for full barrier semantics

[~andy/linux] / arch / arm64 / include / asm / cmpxchg.h

diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
index 56166d7f4a258867d817804c4c17145952895a20..189390ce865334bb1417950400e12273edb3450a 100644 (file)
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -29,7 +29,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
        switch (size) {
        case 1:
                asm volatile("//        __xchg1\n"
-               "1:     ldaxrb  %w0, %2\n"
+               "1:     ldxrb   %w0, %2\n"
                "       stlxrb  %w1, %w3, %2\n"
                "       cbnz    %w1, 1b\n"
                        : "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr)
@@ -38,7 +38,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
                break;
        case 2:
                asm volatile("//        __xchg2\n"
-               "1:     ldaxrh  %w0, %2\n"
+               "1:     ldxrh   %w0, %2\n"
                "       stlxrh  %w1, %w3, %2\n"
                "       cbnz    %w1, 1b\n"
                        : "=&r" (ret), "=&r" (tmp), "+Q" (*(u16 *)ptr)
@@ -47,7 +47,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
                break;
        case 4:
                asm volatile("//        __xchg4\n"
-               "1:     ldaxr   %w0, %2\n"
+               "1:     ldxr    %w0, %2\n"
                "       stlxr   %w1, %w3, %2\n"
                "       cbnz    %w1, 1b\n"
                        : "=&r" (ret), "=&r" (tmp), "+Q" (*(u32 *)ptr)
@@ -56,7 +56,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
                break;
        case 8:
                asm volatile("//        __xchg8\n"
-               "1:     ldaxr   %0, %2\n"
+               "1:     ldxr    %0, %2\n"
                "       stlxr   %w1, %3, %2\n"
                "       cbnz    %w1, 1b\n"
                        : "=&r" (ret), "=&r" (tmp), "+Q" (*(u64 *)ptr)
@@ -67,6 +67,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
                BUILD_BUG();
        }
 
+       smp_mb();
        return ret;
 }