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Commit 50ce749d authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/irq: use hlists for external interrupt handler array 



Use hlists for the hashed array of external interrupt handlers.
Reduces the size of the array by 50% (2KB).

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
parent 8237ac3c

arch/s390/kernel/irq.c

+12 −12
Original line number Diff line number Diff line
@@ -196,13 +196,13 @@ 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[256];



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 */
@@ -227,7 +227,7 @@ 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 +240,9 @@ 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 +264,12 @@ 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;

}
@@ -283,7 +283,7 @@ 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);