[src/trunk]: src/sys/arch/sparc64/include Put "memory" to asm inline for read...

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

details:   https://anonhg.NetBSD.org/src/rev/38ab7c114ace
branches:  trunk
changeset: 805238:38ab7c114ace
user:      nakayama <nakayama%NetBSD.org@localhost>
date:      Thu Dec 25 14:02:03 2014 +0000

description:
Put "memory" to asm inline for reading privilege registers on sun4v
to avoid issuing rdpr %ver before checking cputyp as a result of
code moving by compiler optimization.

diffstat:

 sys/arch/sparc64/include/psl.h |  21 ++++++++++++++++++---
 1 files changed, 18 insertions(+), 3 deletions(-)

diffs (49 lines):

diff -r f3ce6b5d2d6d -r 38ab7c114ace sys/arch/sparc64/include/psl.h
--- a/sys/arch/sparc64/include/psl.h    Thu Dec 25 13:39:41 2014 +0000
+++ b/sys/arch/sparc64/include/psl.h    Thu Dec 25 14:02:03 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: psl.h,v 1.55 2014/12/05 11:34:00 nakayama Exp $ */
+/*     $NetBSD: psl.h,v 1.56 2014/12/25 14:02:03 nakayama Exp $ */
 
 /*
  * Copyright (c) 1992, 1993
@@ -284,6 +284,21 @@
 
 #if defined(_KERNEL) && !defined(_LOCORE)
 
+#if defined(_KERNEL_OPT)
+#include "opt_sparc_arch.h"
+#endif
+
+/*
+ * Put "memory" to asm inline on sun4v to avoid issuing rdpr %ver
+ * before checking cputyp as a result of code moving by compiler
+ * optimization.
+ */
+#ifdef SUN4V
+#define constasm_clobbers "memory"
+#else
+#define constasm_clobbers
+#endif
+
 /*
  * Inlines for manipulating privileged and ancillary state registers
  */
@@ -291,7 +306,7 @@
 static __inline __constfunc type get##name(void)                       \
 {                                                                      \
        type _val;                                                      \
-       __asm(#rd " %" #reg ",%0" : "=r" (_val));                       \
+       __asm(#rd " %" #reg ",%0" : "=r" (_val) : : constasm_clobbers); \
        return _val;                                                    \
 }
 #define SPARC64_RD_DEF(rd, name, reg, type)                            \
@@ -318,7 +333,7 @@
 {                                                                      \
        uint32_t _hi, _lo;                                              \
        __asm(#rd " %" #reg ",%0; srl %0,0,%1; srlx %0,32,%0"           \
-               : "=r" (_hi), "=r" (_lo));                              \
+               : "=r" (_hi), "=r" (_lo) : : constasm_clobbers);        \
        return ((uint64_t)_hi << 32) | _lo;                             \
 }
 #define SPARC64_RD64_DEF(rd, name, reg)                                        \