x86/paravirt: add spin_lock_flags lock op

It is useful for a pv_lock_ops backend to know whether interrupts are
enabled or not in the context a spin_lock is being called.  This
allows it to enable interrupts while spinning, which could be
particularly helpful when spinning becomes blocking.

The default implementation just calls the normal spin_lock op,
ignoring the flags.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/asm-x86/spinlock.h b/include/asm-x86/spinlock.h
index e39c790dbfd2..b755ea86367e 100644
--- a/include/asm-x86/spinlock.h
+++ b/include/asm-x86/spinlock.h
@@ -182,8 +182,6 @@ static __always_inline void __ticket_spin_unlock(raw_spinlock_t *lock)
 }
 #endif
 
-#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
-
 #ifdef CONFIG_PARAVIRT
 /*
  * Define virtualization-friendly old-style lock byte lock, for use in
@@ -272,6 +270,13 @@ static __always_inline void __raw_spin_unlock(raw_spinlock_t *lock)
 {
         __ticket_spin_unlock(lock);
 }
+
+static __always_inline void __raw_spin_lock_flags(raw_spinlock_t *lock,
+                                                  unsigned long flags)
+{
+        __raw_spin_lock(lock);
+}
+
 #endif  /* CONFIG_PARAVIRT */
 
 static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)