[src/trunk]: src/common/lib/libc/arch/aarch64/atomic - atomic_*_{8, 16}_nv() m...

[ryo <ryo%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a4b2b8deb873
branches:  trunk
changeset: 839155:a4b2b8deb873
user:      ryo <ryo%NetBSD.org@localhost>
date:      Fri Feb 08 06:56:56 2019 +0000

description:
- atomic_*_{8,16}_nv() must return a new value, not an old value.
- use "dmb sy" for atomic_*{8,16}_nv() in the same way as atomic_*{32,64}_nv().

diffstat:

 common/lib/libc/arch/aarch64/atomic/atomic_op_asm.h |  14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diffs (37 lines):

diff -r b986ff3ba08f -r a4b2b8deb873 common/lib/libc/arch/aarch64/atomic/atomic_op_asm.h
--- a/common/lib/libc/arch/aarch64/atomic/atomic_op_asm.h       Fri Feb 08 06:33:04 2019 +0000
+++ b/common/lib/libc/arch/aarch64/atomic/atomic_op_asm.h       Fri Feb 08 06:56:56 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: atomic_op_asm.h,v 1.2 2019/02/06 05:33:14 ryo Exp $ */
+/* $NetBSD: atomic_op_asm.h,v 1.3 2019/02/08 06:56:56 ryo Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -49,10 +49,10 @@
 ENTRY_NP(_atomic_##OP##_8_nv)                                          ;\
        mov     x4, x0                  /* need r0 for return value */  ;\
 1:     ldxrb   w0, [x4]                /* load old value */            ;\
-       INSN    w2, w0, w1              /* calc new (return) value */   ;\
-       stxrb   w3, w2, [x4]            /* try to store */              ;\
+       INSN    w0, w0, w1              /* calc new (return) value */   ;\
+       stxrb   w3, w0, [x4]            /* try to store */              ;\
        cbnz    w3, 1b                  /*   succeed? no, try again */  ;\
-       dmb     st                                                      ;\
+       dmb     sy                                                      ;\
        ret                             /* return new value */          ;\
 END(_atomic_##OP##_8_nv)
 
@@ -71,10 +71,10 @@
 ENTRY_NP(_atomic_##OP##_16_nv)                                         ;\
        mov     x4, x0                  /* need r0 for return value */  ;\
 1:     ldxrh   w0, [x4]                /* load old value */            ;\
-       INSN    w2, w0, w1              /* calc new (return) value */   ;\
-       stxrh   w3, w2, [x4]            /* try to store */              ;\
+       INSN    w0, w0, w1              /* calc new (return) value */   ;\
+       stxrh   w3, w0, [x4]            /* try to store */              ;\
        cbnz    w3, 1b                  /*   succeed? no, try again */  ;\
-       dmb     st                                                      ;\
+       dmb     sy                                                      ;\
        ret                             /* return new value */          ;\
 END(_atomic_##OP##_16_nv)