From 7c8abf0ee42a485ac226dba8f0326b5b26477931 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Wed, 20 Aug 2008 17:02:20 -0700
Subject: [PATCH] --- yaml --- r: 113247 b: refs/heads/master c:
 1e696f638b523958ee3d95e655becdb4c4b6fcde h: refs/heads/master i:   113245:
 6f5d0f3f2313e9cdc379ceba094182448439aea9   113243:
 e29c9c67fdd4d461f05d62be745f246787c9e0b1   113239:
 f1a4828b996560abec18d02d557544f6c357280d   113231:
 52a32666fa3536209aebaee272db7fdbffe82deb   113215:
 24872438d1a56dd8ddea5b4fc4d7d4419b3e07dc v: v3

---
 [refs]                        |  2 +-
 trunk/arch/x86/xen/spinlock.c | 30 +++++++++++++++++++++++++++---
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index a93de29d5120..2d7f55555960 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 994025caba3e6beade9bde84dd1b70d9d250f27b
+refs/heads/master: 1e696f638b523958ee3d95e655becdb4c4b6fcde
diff --git a/trunk/arch/x86/xen/spinlock.c b/trunk/arch/x86/xen/spinlock.c
index 0d8f3b2d9bec..e6061f2e64f2 100644
--- a/trunk/arch/x86/xen/spinlock.c
+++ b/trunk/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,