1 files changed, 32 insertions, 53 deletions

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index b34ba0ea96a..8ac2097f13d 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -196,21 +196,23 @@ asmlinkage void do_softirq(void)
  * ext_int_hash[index] is the list head for all external interrupts that hash
  * to this index.
  */
-static struct list_head ext_int_hash[256];
+static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
 
 struct ext_int_info {
 	ext_int_handler_t handler;
-	u16 code;
-	struct list_head entry;
+	struct hlist_node entry;
 	struct rcu_head rcu;
+	u16 code;
 };
 
 /* ext_int_hash_lock protects the handler lists for external interrupts */
-DEFINE_SPINLOCK(ext_int_hash_lock);
+static DEFINE_SPINLOCK(ext_int_hash_lock);
 
 static inline int ext_hash(u16 code)
 {
-	return (code + (code >> 9)) & 0xff;
+	BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
+
+	return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
 }
 
 int register_external_interrupt(u16 code, ext_int_handler_t handler)
@@ -227,7 +229,7 @@ int register_external_interrupt(u16 code, ext_int_handler_t handler)
 	index = ext_hash(code);
 
 	spin_lock_irqsave(&ext_int_hash_lock, flags);
-	list_add_rcu(&p->entry, &ext_int_hash[index]);
+	hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
 	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 	return 0;
 }
@@ -240,9 +242,9 @@ int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
 	int index = ext_hash(code);
 
 	spin_lock_irqsave(&ext_int_hash_lock, flags);
-	list_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
+	hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
 		if (p->code == code && p->handler == handler) {
-			list_del_rcu(&p->entry);
+			hlist_del_rcu(&p->entry);
 			kfree_rcu(p, rcu);
 		}
 	}
@@ -264,12 +266,12 @@ static irqreturn_t do_ext_interrupt(int irq, void *dummy)
 
 	index = ext_hash(ext_code.code);
 	rcu_read_lock();
-	list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
-		if (likely(p->code == ext_code.code))
-			p->handler(ext_code, regs->int_parm,
-				   regs->int_parm_long);
+	hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
+		if (unlikely(p->code != ext_code.code))
+			continue;
+		p->handler(ext_code, regs->int_parm, regs->int_parm_long);
+	}
 	rcu_read_unlock();
-
 	return IRQ_HANDLED;
 }
 
@@ -283,55 +285,32 @@ void __init init_ext_interrupts(void)
 	int idx;
 
 	for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
-		INIT_LIST_HEAD(&ext_int_hash[idx]);
+		INIT_HLIST_HEAD(&ext_int_hash[idx]);
 
 	irq_set_chip_and_handler(EXT_INTERRUPT,
 				 &dummy_irq_chip, handle_percpu_irq);
 	setup_irq(EXT_INTERRUPT, &external_interrupt);
 }
 
-static DEFINE_SPINLOCK(sc_irq_lock);
-static int sc_irq_refcount;
-
-void service_subclass_irq_register(void)
-{
-	spin_lock(&sc_irq_lock);
-	if (!sc_irq_refcount)
-		ctl_set_bit(0, 9);
-	sc_irq_refcount++;
-	spin_unlock(&sc_irq_lock);
-}
-EXPORT_SYMBOL(service_subclass_irq_register);
-
-void service_subclass_irq_unregister(void)
-{
-	spin_lock(&sc_irq_lock);
-	sc_irq_refcount--;
-	if (!sc_irq_refcount)
-		ctl_clear_bit(0, 9);
-	spin_unlock(&sc_irq_lock);
-}
-EXPORT_SYMBOL(service_subclass_irq_unregister);
-
-static DEFINE_SPINLOCK(ma_subclass_lock);
-static int ma_subclass_refcount;
+static DEFINE_SPINLOCK(irq_subclass_lock);
+static unsigned char irq_subclass_refcount[64];
 
-void measurement_alert_subclass_register(void)
+void irq_subclass_register(enum irq_subclass subclass)
 {
-	spin_lock(&ma_subclass_lock);
-	if (!ma_subclass_refcount)
-		ctl_set_bit(0, 5);
-	ma_subclass_refcount++;
-	spin_unlock(&ma_subclass_lock);
+	spin_lock(&irq_subclass_lock);
+	if (!irq_subclass_refcount[subclass])
+		ctl_set_bit(0, subclass);
+	irq_subclass_refcount[subclass]++;
+	spin_unlock(&irq_subclass_lock);
 }
-EXPORT_SYMBOL(measurement_alert_subclass_register);
+EXPORT_SYMBOL(irq_subclass_register);
 
-void measurement_alert_subclass_unregister(void)
+void irq_subclass_unregister(enum irq_subclass subclass)
 {
-	spin_lock(&ma_subclass_lock);
-	ma_subclass_refcount--;
-	if (!ma_subclass_refcount)
-		ctl_clear_bit(0, 5);
-	spin_unlock(&ma_subclass_lock);
+	spin_lock(&irq_subclass_lock);
+	irq_subclass_refcount[subclass]--;
+	if (!irq_subclass_refcount[subclass])
+		ctl_clear_bit(0, subclass);
+	spin_unlock(&irq_subclass_lock);
 }
-EXPORT_SYMBOL(measurement_alert_subclass_unregister);
+EXPORT_SYMBOL(irq_subclass_unregister);