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authorTakashi Yoshii <yoshii.takashi@renesas.com>2009-01-28 09:29:13 +0000
committerPaul Mundt <lethal@linux-sh.org>2009-01-29 11:56:03 +0900
commitc20f326a62c046ee958c3aa584f183201adb229f (patch)
tree1e8c72e5fd824d4182e14a21410c0e714e080dfe /arch/sh
parent03f07876df2565321871a2dbf33c5c737df185df (diff)
downloadlinux-c20f326a62c046ee958c3aa584f183201adb229f.tar.gz
sh: Fix up T-bit error handling in SH-4A mutex fastpath.
This corrects a deadlock encountered on ap325 in the cases where the
mutex is contended and the slow-path needs to be fallen back upon.

Signed-off-by: Takashi YOSHII <yoshii.takashi@renesas.com>
Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh')
-rw-r--r--arch/sh/include/asm/mutex-llsc.h21
1 files changed, 9 insertions, 12 deletions
diff --git a/arch/sh/include/asm/mutex-llsc.h b/arch/sh/include/asm/mutex-llsc.h
index ee839ee58ac8..090358a7e1bb 100644
--- a/arch/sh/include/asm/mutex-llsc.h
+++ b/arch/sh/include/asm/mutex-llsc.h
@@ -21,38 +21,36 @@
 static inline void
 __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
 {
-	int __ex_flag, __res;
+	int __done, __res;
 
 	__asm__ __volatile__ (
 		"movli.l	@%2, %0	\n"
 		"add		#-1, %0	\n"
 		"movco.l	%0, @%2	\n"
 		"movt		%1	\n"
-		: "=&z" (__res), "=&r" (__ex_flag)
+		: "=&z" (__res), "=&r" (__done)
 		: "r" (&(count)->counter)
 		: "t");
 
-	__res |= !__ex_flag;
-	if (unlikely(__res != 0))
+	if (unlikely(!__done || __res != 0))
 		fail_fn(count);
 }
 
 static inline int
 __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
 {
-	int __ex_flag, __res;
+	int __done, __res;
 
 	__asm__ __volatile__ (
 		"movli.l	@%2, %0	\n"
 		"add		#-1, %0	\n"
 		"movco.l	%0, @%2	\n"
 		"movt		%1	\n"
-		: "=&z" (__res), "=&r" (__ex_flag)
+		: "=&z" (__res), "=&r" (__done)
 		: "r" (&(count)->counter)
 		: "t");
 
-	__res |= !__ex_flag;
-	if (unlikely(__res != 0))
+	if (unlikely(!__done || __res != 0))
 		__res = fail_fn(count);
 
 	return __res;
@@ -61,19 +59,18 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
 static inline void
 __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
 {
-	int __ex_flag, __res;
+	int __done, __res;
 
 	__asm__ __volatile__ (
 		"movli.l	@%2, %0	\n\t"
 		"add		#1, %0	\n\t"
 		"movco.l	%0, @%2 \n\t"
 		"movt		%1	\n\t"
-		: "=&z" (__res), "=&r" (__ex_flag)
+		: "=&z" (__res), "=&r" (__done)
 		: "r" (&(count)->counter)
 		: "t");
 
-	__res |= !__ex_flag;
-	if (unlikely(__res <= 0))
+	if (unlikely(!__done || __res <= 0))
 		fail_fn(count);
 }