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Subject[PATCH 2/3] x86: ticket spin locks: factor out more common code
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Nick Piggin <npiggin@suse.de>

---
include/asm-x86/spinlock.h | 42 ++++++++++++++++--------------------------
1 file changed, 16 insertions(+), 26 deletions(-)

--- linux-x86.orig/include/asm-x86/spinlock.h
+++ linux-x86/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_spi
: "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_spi
}
#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;
+}
+
#ifdef CONFIG_PARAVIRT
/*
* Define virtualization-friendly old-style lock byte lock, for use in





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