Module: xenomai-head
Branch: master
Commit: 57f4b7a8b3b14954d008410c5c963cf79aeac2ae
URL:
http://git.xenomai.org/?p=xenomai-head.git;a=commit;h=57f4b7a8b3b14954d008410c5c963cf79aeac2ae
Author: Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org>
Date: Tue Jun 9 22:50:01 2009 +0200
Improve decrementer user-space tsc emulation
---
include/asm-arm/syscall.h | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/include/asm-arm/syscall.h b/include/asm-arm/syscall.h
index a6d1534..743d4ef 100644
--- a/include/asm-arm/syscall.h
+++ b/include/asm-arm/syscall.h
@@ -286,18 +286,21 @@ static inline unsigned long long __xn_rdtsc(void)
return (before & ~((unsigned long long) mask)) | (counter & mask);
#elif XNARCH_ARM_TSC_TYPE == __XN_TSC_TYPE_DECREMENTER
+ volatile unsigned long long *const tscp = __xn_tscinfo.u.dec.tsc;
+ volatile unsigned *const counterp = __xn_tscinfo.u.dec.counter;
+ volatile unsigned *const last_cntp = __xn_tscinfo.u.dec.last_cnt;
const unsigned mask = __xn_tscinfo.u.dec.mask;
- unsigned long long after, before;
+ register unsigned long long after, before;
unsigned counter, last_cnt;
+ __asm__ ("ldmia %1, %M0\n": "=r"(after): "r"(tscp), "m"(*tscp));
do {
- before = *__xn_tscinfo.u.dec.tsc;
- counter = *__xn_tscinfo.u.dec.counter;
- last_cnt = *__xn_tscinfo.u.dec.last_cnt;
+ before = after;
+ counter = *counterp;
+ last_cnt = *last_cntp;
/* compiler barrier. */
__asm__ __volatile__ ("" : /* */ : /* */ : "memory");
-
- after = *__xn_tscinfo.u.dec.tsc;
+ __asm__ ("ldmia %1, %M0\n": "=r"(after): "r"(tscp), "m"(*tscp));
} while (after != before);
counter &= mask;
_______________________________________________
Xenomai-git mailing list
Xenomai-git@gna.org
https://mail.gna.org/listinfo/xenomai-git
