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authorAoi Shinkai <shinkoi2005@gmail.com>2009-06-10 16:15:42 +0000
committerPaul Mundt <lethal@linux-sh.org>2009-06-11 09:31:55 +0300
commit4c7c99788631bab177bd51e15e893be4689bb085 (patch)
tree52e50e0b2a30b31dc8c6460e98279b3c1b47c476 /arch/sh
parentf168dd00a9440a6f644db73bda47718fd12008e4 (diff)
sh: Fix sh4a llsc-based cmpxchg()
This fixes up a typo in the ll/sc based cmpxchg code which apparently wasn't getting a lot of testing due to the swapped old/new pair. With that fixed up, the ll/sc code also starts using it and provides its own atomic_add_unless(). Signed-off-by: Aoi Shinkai <shinkoi2005@gmail.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh')
-rw-r--r--arch/sh/include/asm/atomic-llsc.h27
-rw-r--r--arch/sh/include/asm/atomic.h4
-rw-r--r--arch/sh/include/asm/cmpxchg-llsc.h2
-rw-r--r--arch/sh/include/asm/spinlock.h2
4 files changed, 31 insertions, 4 deletions
diff --git a/arch/sh/include/asm/atomic-llsc.h b/arch/sh/include/asm/atomic-llsc.h
index 4b00b78e3f4..b040e1e0861 100644
--- a/arch/sh/include/asm/atomic-llsc.h
+++ b/arch/sh/include/asm/atomic-llsc.h
@@ -104,4 +104,31 @@ static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
: "t");
}
+#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
+
+/**
+ * atomic_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+static inline int atomic_add_unless(atomic_t *v, int a, int u)
+{
+ int c, old;
+ c = atomic_read(v);
+ for (;;) {
+ if (unlikely(c == (u)))
+ break;
+ old = atomic_cmpxchg((v), c, c + (a));
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+
+ return c != (u);
+}
+
#endif /* __ASM_SH_ATOMIC_LLSC_H */
diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h
index 6327ffbb199..978b58efb1e 100644
--- a/arch/sh/include/asm/atomic.h
+++ b/arch/sh/include/asm/atomic.h
@@ -45,7 +45,7 @@
#define atomic_inc(v) atomic_add(1,(v))
#define atomic_dec(v) atomic_sub(1,(v))
-#ifndef CONFIG_GUSA_RB
+#if !defined(CONFIG_GUSA_RB) && !defined(CONFIG_CPU_SH4A)
static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
{
int ret;
@@ -73,7 +73,7 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
return ret != u;
}
-#endif
+#endif /* !CONFIG_GUSA_RB && !CONFIG_CPU_SH4A */
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
diff --git a/arch/sh/include/asm/cmpxchg-llsc.h b/arch/sh/include/asm/cmpxchg-llsc.h
index 0fac3da536c..47136661a20 100644
--- a/arch/sh/include/asm/cmpxchg-llsc.h
+++ b/arch/sh/include/asm/cmpxchg-llsc.h
@@ -55,7 +55,7 @@ __cmpxchg_u32(volatile int *m, unsigned long old, unsigned long new)
"mov %0, %1 \n\t"
"cmp/eq %1, %3 \n\t"
"bf 2f \n\t"
- "mov %3, %0 \n\t"
+ "mov %4, %0 \n\t"
"2: \n\t"
"movco.l %0, @%2 \n\t"
"bf 1b \n\t"
diff --git a/arch/sh/include/asm/spinlock.h b/arch/sh/include/asm/spinlock.h
index 60283565f89..a28c9f0053f 100644
--- a/arch/sh/include/asm/spinlock.h
+++ b/arch/sh/include/asm/spinlock.h
@@ -26,7 +26,7 @@
#define __raw_spin_is_locked(x) ((x)->lock <= 0)
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
#define __raw_spin_unlock_wait(x) \
- do { cpu_relax(); } while ((x)->lock)
+ do { while (__raw_spin_is_locked(x)) cpu_relax(); } while (0)
/*
* Simple spin lock operations. There are two variants, one clears IRQ's