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authorJan Beulich2008-09-05 14:26:39 +0200
committerIngo Molnar2008-09-05 17:05:56 +0200
commit08f5fcbe6e0ea029c7e9b1b1c338700ab7809daf (patch)
tree46de345d9e5d8960ad0668ba8815475d37c4c78e /include
parentx86: ticket spin locks: fix asm constraints (diff)
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x86: ticket spin locks: factor out more common code
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
-rw-r--r--include/asm-x86/spinlock.h42
1 files changed, 16 insertions, 26 deletions
diff --git a/include/asm-x86/spinlock.h b/include/asm-x86/spinlock.h
index acd9bdda55cf..63d3b610a5ef 100644
--- a/include/asm-x86/spinlock.h
+++ b/include/asm-x86/spinlock.h
@@ -54,19 +54,7 @@
* much between them in performance though, especially as locks are out of line.
*/
#if (NR_CPUS < 256)
-static inline int __ticket_spin_is_locked(raw_spinlock_t *lock)
-{
- int tmp = ACCESS_ONCE(lock->slock);
-
- return (((tmp >> 8) & 0xff) != (tmp & 0xff));
-}
-
-static inline int __ticket_spin_is_contended(raw_spinlock_t *lock)
-{
- int tmp = ACCESS_ONCE(lock->slock);
-
- return (((tmp >> 8) - tmp) & 0xff) > 1;
-}
+#define TICKET_SHIFT 8
static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock)
{
@@ -116,19 +104,7 @@ static __always_inline void __ticket_spin_unlock(raw_spinlock_t *lock)
: "memory", "cc");
}
#else
-static inline int __ticket_spin_is_locked(raw_spinlock_t *lock)
-{
- int tmp = ACCESS_ONCE(lock->slock);
-
- return (((tmp >> 16) & 0xffff) != (tmp & 0xffff));
-}
-
-static inline int __ticket_spin_is_contended(raw_spinlock_t *lock)
-{
- int tmp = ACCESS_ONCE(lock->slock);
-
- return (((tmp >> 16) - tmp) & 0xffff) > 1;
-}
+#define TICKET_SHIFT 16
static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock)
{
@@ -182,6 +158,20 @@ static __always_inline void __ticket_spin_unlock(raw_spinlock_t *lock)
}
#endif
+static inline int __ticket_spin_is_locked(raw_spinlock_t *lock)
+{
+ int tmp = ACCESS_ONCE(lock->slock);
+
+ return !!(((tmp >> TICKET_SHIFT) ^ tmp) & ((1 << TICKET_SHIFT) - 1));
+}
+
+static inline int __ticket_spin_is_contended(raw_spinlock_t *lock)
+{
+ int tmp = ACCESS_ONCE(lock->slock);
+
+ return (((tmp >> TICKET_SHIFT) - tmp) & ((1 << TICKET_SHIFT) - 1)) > 1;
+}
+
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
#ifdef CONFIG_PARAVIRT