x86: spinlocks: define dummy __raw_spin_is_contended

Architectures other than mips and x86 are not using ticket spinlocks.
Therefore, the contention on the lock is meaningless, since there is
nobody known to be waiting on it (arguably /fairly/ unfair locks).

Dummy it out to return 0 on other architectures.

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 8 insertions, 0 deletions

diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h
index 1a1f320c30d8..0884947ebe27 100644
--- a/arch/mips/include/asm/spinlock.h
+++ b/arch/mips/include/asm/spinlock.h
@@ -51,6 +51,7 @@ static inline int __raw_spin_is_contended(raw_spinlock_t *lock)
 
         return (((counters >> 14) - counters) & 0x1fff) > 1;
 }
+#define __raw_spin_is_contended __raw_spin_is_contended
 
 static inline void __raw_spin_lock(raw_spinlock_t *lock)
 {
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index ba3e2ff6aedc..c09a14127584 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -1402,6 +1402,7 @@ static inline int __raw_spin_is_contended(struct raw_spinlock *lock)
 {
         return PVOP_CALL1(int, pv_lock_ops.spin_is_contended, lock);
 }
+#define __raw_spin_is_contended __raw_spin_is_contended
 
 static __always_inline void __raw_spin_lock(struct raw_spinlock *lock)
 {
diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h
index d17c91981da2..8247e94ac6b1 100644
--- a/arch/x86/include/asm/spinlock.h
+++ b/arch/x86/include/asm/spinlock.h
@@ -245,6 +245,7 @@ static inline int __raw_spin_is_contended(raw_spinlock_t *lock)
 {
         return __ticket_spin_is_contended(lock);
 }
+#define __raw_spin_is_contended __raw_spin_is_contended
 
 static __always_inline void __raw_spin_lock(raw_spinlock_t *lock)
 {
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index e0c0fccced46..a0c66a2e00ad 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -124,7 +124,12 @@ do {								\
 #ifdef CONFIG_GENERIC_LOCKBREAK
 #define spin_is_contended(lock) ((lock)->break_lock)
 #else
+
+#ifdef __raw_spin_is_contended
 #define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock)
+#else
+#define spin_is_contended(lock) (((void)(lock), 0))
+#endif /*__raw_spin_is_contended*/
 #endif
 
 /**