[patch 3/3] spinlock fix #3: type-checking spinlock primitives, x86

From: Ingo Molnar
Date: Thu Jan 20 2005 - 11:21:27 EST



[this patch didnt change due to can_lock but i've resent it so that the
patch stream is complete.]

--
this patch would have caught the bug in -BK-curr (that patch #1 fixes),
via a compiler warning. Test-built/booted on x86.

Ingo

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

--- linux/include/asm-i386/spinlock.h.orig
+++ linux/include/asm-i386/spinlock.h
@@ -36,7 +36,10 @@ typedef struct {

#define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 SPINLOCK_MAGIC_INIT }

-#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
+static inline void spin_lock_init(spinlock_t *lock)
+{
+ *lock = SPIN_LOCK_UNLOCKED;
+}

/*
* Simple spin lock operations. There are two variants, one clears IRQ's
@@ -45,8 +48,17 @@ typedef struct {
* We make no fairness assumptions. They have a cost.
*/

-#define spin_is_locked(x) (*(volatile signed char *)(&(x)->lock) <= 0)
-#define spin_unlock_wait(x) do { barrier(); } while(spin_is_locked(x))
+static inline int spin_is_locked(spinlock_t *lock)
+{
+ return *(volatile signed char *)(&lock->lock) <= 0;
+}
+
+static inline void spin_unlock_wait(spinlock_t *lock)
+{
+ do {
+ barrier();
+ } while (spin_is_locked(lock));
+}

#define spin_lock_string \
"\n1:\t" \
-
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