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authorMiod Vallat <miod@cvs.openbsd.org>2013-12-26 21:02:38 +0000
committerMiod Vallat <miod@cvs.openbsd.org>2013-12-26 21:02:38 +0000
commit2bc60b2f2f0bccab1a38b485aaa8221aa8c9521d (patch)
tree344e7eed6c854134b2183abc565bf25620e2b0eb /sys/arch
parent35eedb96d89d1bea4c1850759744df5908a15fee (diff)
When running the ll/sc version of the mutex code (for MULTIPROCESSOR kernels),
correctly handle sc failures. All other ll/sc constructs were doing this correctly but apparently noone had noticed mutex did not.
Diffstat (limited to 'sys/arch')
-rw-r--r--sys/arch/octeon/octeon/mutex.c15
-rw-r--r--sys/arch/sgi/sgi/mutex.c15
2 files changed, 18 insertions, 12 deletions
diff --git a/sys/arch/octeon/octeon/mutex.c b/sys/arch/octeon/octeon/mutex.c
index 2026a6088e3..8876a5edd66 100644
--- a/sys/arch/octeon/octeon/mutex.c
+++ b/sys/arch/octeon/octeon/mutex.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mutex.c,v 1.5 2011/04/21 04:34:12 miod Exp $ */
+/* $OpenBSD: mutex.c,v 1.6 2013/12/26 21:02:37 miod Exp $ */
/*
* Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
@@ -39,12 +39,15 @@ try_lock(struct mutex *mtx)
asm volatile (
".set noreorder\n"
- "ll %0, %2\n"
- "bnez %0, 1f\n"
- "nop\n"
- "li %1, 1\n"
- "sc %1, %2\n"
"1:\n"
+ "ll %0, %2\n" /* tmp = mtx->mtx_lock */
+ "bnez %0, 2f\n"
+ " li %1, 0\n" /* ret = 0 */
+ "li %1, 1\n" /* ret = 1 */
+ "sc %1, %2\n" /* mtx->mtx_lock = 1 */
+ "beqz %1, 1b\n" /* update failed */
+ " nop\n"
+ "2:\n"
".set reorder\n"
: "+r"(tmp), "+r"(ret)
: "m"(mtx->mtx_lock));
diff --git a/sys/arch/sgi/sgi/mutex.c b/sys/arch/sgi/sgi/mutex.c
index 2c85fa89e19..3fa43dac71c 100644
--- a/sys/arch/sgi/sgi/mutex.c
+++ b/sys/arch/sgi/sgi/mutex.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mutex.c,v 1.12 2011/04/21 04:34:12 miod Exp $ */
+/* $OpenBSD: mutex.c,v 1.13 2013/12/26 21:02:37 miod Exp $ */
/*
* Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
@@ -39,12 +39,15 @@ try_lock(struct mutex *mtx)
asm volatile (
".set noreorder\n"
- "ll %0, %2\n"
- "bnez %0, 1f\n"
- "nop\n"
- "li %1, 1\n"
- "sc %1, %2\n"
"1:\n"
+ "ll %0, %2\n" /* tmp = mtx->mtx_lock */
+ "bnez %0, 2f\n"
+ " li %1, 0\n" /* ret = 0 */
+ "li %1, 1\n" /* ret = 1 */
+ "sc %1, %2\n" /* mtx->mtx_lock = 1 */
+ "beqz %1, 1b\n" /* update failed */
+ " nop\n"
+ "2:\n"
".set reorder\n"
: "+r"(tmp), "+r"(ret)
: "m"(mtx->mtx_lock));