lockref: Implement lockref for Itanium

All the cool kids are doing this, join in the fun.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 6 insertions, 0 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index b36370d3eab9..566642266324 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -43,6 +43,7 @@ config IA64
         select SYSCTL_ARCH_UNALIGN_NO_WARN
         select HAVE_MOD_ARCH_SPECIFIC
         select MODULES_USE_ELF_RELA
+        select ARCH_USE_CMPXCHG_LOCKREF
         default y
         help
           The Itanium Processor Family is Intel's 64-bit successor to
diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h
index 54ff557d474e..45698cd15b7b 100644
--- a/arch/ia64/include/asm/spinlock.h
+++ b/arch/ia64/include/asm/spinlock.h
@@ -102,6 +102,11 @@ static inline int __ticket_spin_is_contended(arch_spinlock_t *lock)
         return ((tmp - (tmp >> TICKET_SHIFT)) & TICKET_MASK) > 1;
 }
 
+static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
+{
+        return !(((lock.lock >> TICKET_SHIFT) ^ lock.lock) & TICKET_MASK);
+}
+
 static inline int arch_spin_is_locked(arch_spinlock_t *lock)
 {
         return __ticket_spin_is_locked(lock);