1 files changed, 27 insertions, 3 deletions

diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 0d8f3b2d9bec..e6061f2e64f2 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -23,6 +23,7 @@ static struct xen_spinlock_stats
         u32 taken_slow_nested;
         u32 taken_slow_pickup;
         u32 taken_slow_spurious;
+        u32 taken_slow_irqenable;
 
         u64 released;
         u32 released_slow;
@@ -167,12 +168,13 @@ static inline void unspinning_lock(struct xen_spinlock *xl, struct xen_spinlock
         __get_cpu_var(lock_spinners) = prev;
 }
 
-static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
+static noinline int xen_spin_lock_slow(struct raw_spinlock *lock, bool irq_enable)
 {
         struct xen_spinlock *xl = (struct xen_spinlock *)lock;
         struct xen_spinlock *prev;
         int irq = __get_cpu_var(lock_kicker_irq);
         int ret;
+        unsigned long flags;
 
         /* If kicker interrupts not initialized yet, just spin */
         if (irq == -1)
@@ -181,6 +183,12 @@ static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
         /* announce we're spinning */
         prev = spinning_lock(xl);
 
+        flags = __raw_local_save_flags();
+        if (irq_enable) {
+                ADD_STATS(taken_slow_irqenable, 1);
+                raw_local_irq_enable();
+        }
+
         ADD_STATS(taken_slow, 1);
         ADD_STATS(taken_slow_nested, prev != NULL);
 
@@ -220,11 +228,12 @@ static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
         kstat_this_cpu.irqs[irq]++;
 
 out:
+        raw_local_irq_restore(flags);
         unspinning_lock(xl, prev);
         return ret;
 }
 
-static void xen_spin_lock(struct raw_spinlock *lock)
+static inline void __xen_spin_lock(struct raw_spinlock *lock, bool irq_enable)
 {
         struct xen_spinlock *xl = (struct xen_spinlock *)lock;
         unsigned timeout;
@@ -254,11 +263,23 @@ static void xen_spin_lock(struct raw_spinlock *lock)
                     : "memory");
 
                 spin_time_accum_fast(start_spin_fast);
-        } while (unlikely(oldval != 0 && (TIMEOUT == ~0 || !xen_spin_lock_slow(lock))));
+
+        } while (unlikely(oldval != 0 &&
+                          (TIMEOUT == ~0 || !xen_spin_lock_slow(lock, irq_enable))));
 
         spin_time_accum(start_spin);
 }
 
+static void xen_spin_lock(struct raw_spinlock *lock)
+{
+        __xen_spin_lock(lock, false);
+}
+
+static void xen_spin_lock_flags(struct raw_spinlock *lock, unsigned long flags)
+{
+        __xen_spin_lock(lock, !raw_irqs_disabled_flags(flags));
+}
+
 static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
 {
         int cpu;
@@ -323,6 +344,7 @@ void __init xen_init_spinlocks(void)
         pv_lock_ops.spin_is_locked = xen_spin_is_locked;
         pv_lock_ops.spin_is_contended = xen_spin_is_contended;
         pv_lock_ops.spin_lock = xen_spin_lock;
+        pv_lock_ops.spin_lock_flags = xen_spin_lock_flags;
         pv_lock_ops.spin_trylock = xen_spin_trylock;
         pv_lock_ops.spin_unlock = xen_spin_unlock;
 }
@@ -353,6 +375,8 @@ static int __init xen_spinlock_debugfs(void)
                            &spinlock_stats.taken_slow_pickup);
         debugfs_create_u32("taken_slow_spurious", 0444, d_spin_debug,
                            &spinlock_stats.taken_slow_spurious);
+        debugfs_create_u32("taken_slow_irqenable", 0444, d_spin_debug,
+                           &spinlock_stats.taken_slow_irqenable);
 
         debugfs_create_u64("released", 0444, d_spin_debug, &spinlock_stats.released);
         debugfs_create_u32("released_slow", 0444, d_spin_debug,