diff options
| -rw-r--r-- | arch/s390/kernel/irq.c | 83 |
1 files changed, 46 insertions, 37 deletions
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index e3264f6a9720..1f4050d45f78 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -88,15 +88,6 @@ int show_interrupts(struct seq_file *p, void *v) } /* - * For compatibilty only. S/390 specific setup of interrupts et al. is done - * much later in init_channel_subsystem(). - */ -void __init init_IRQ(void) -{ - /* nothing... */ -} - -/* * Switch to the asynchronous interrupt stack for softirq execution. */ asmlinkage void do_softirq(void) @@ -144,28 +135,45 @@ void init_irq_proc(void) #endif /* - * ext_int_hash[index] is the start of the list for all external interrupts - * that hash to this index. With the current set of external interrupts - * (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000 - * iucv and 0x2603 pfault) this is always the first element. + * 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]; struct ext_int_info { - struct ext_int_info *next; ext_int_handler_t handler; u16 code; + struct list_head entry; + struct rcu_head rcu; }; -static struct ext_int_info *ext_int_hash[256]; +/* ext_int_hash_lock protects the handler lists for external interrupts */ +DEFINE_SPINLOCK(ext_int_hash_lock); + +static void __init init_external_interrupts(void) +{ + int idx; + + for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++) + INIT_LIST_HEAD(&ext_int_hash[idx]); +} static inline int ext_hash(u16 code) { return (code + (code >> 9)) & 0xff; } +static void ext_int_hash_update(struct rcu_head *head) +{ + struct ext_int_info *p = container_of(head, struct ext_int_info, rcu); + + kfree(p); +} + int register_external_interrupt(u16 code, ext_int_handler_t handler) { struct ext_int_info *p; + unsigned long flags; int index; p = kmalloc(sizeof(*p), GFP_ATOMIC); @@ -174,33 +182,27 @@ int register_external_interrupt(u16 code, ext_int_handler_t handler) p->code = code; p->handler = handler; index = ext_hash(code); - p->next = ext_int_hash[index]; - ext_int_hash[index] = p; + + spin_lock_irqsave(&ext_int_hash_lock, flags); + list_add_rcu(&p->entry, &ext_int_hash[index]); + spin_unlock_irqrestore(&ext_int_hash_lock, flags); return 0; } EXPORT_SYMBOL(register_external_interrupt); int unregister_external_interrupt(u16 code, ext_int_handler_t handler) { - struct ext_int_info *p, *q; - int index; + struct ext_int_info *p; + unsigned long flags; + int index = ext_hash(code); - index = ext_hash(code); - q = NULL; - p = ext_int_hash[index]; - while (p) { - if (p->code == code && p->handler == handler) - break; - q = p; - p = p->next; - } - if (!p) - return -ENOENT; - if (q) - q->next = p->next; - else - ext_int_hash[index] = p->next; - kfree(p); + spin_lock_irqsave(&ext_int_hash_lock, flags); + list_for_each_entry_rcu(p, &ext_int_hash[index], entry) + if (p->code == code && p->handler == handler) { + list_del_rcu(&p->entry); + call_rcu(&p->rcu, ext_int_hash_update); + } + spin_unlock_irqrestore(&ext_int_hash_lock, flags); return 0; } EXPORT_SYMBOL(unregister_external_interrupt); @@ -224,15 +226,22 @@ void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code, kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++; if (code != 0x1004) __get_cpu_var(s390_idle).nohz_delay = 1; + index = ext_hash(code); - for (p = ext_int_hash[index]; p; p = p->next) { + rcu_read_lock(); + list_for_each_entry_rcu(p, &ext_int_hash[index], entry) if (likely(p->code == code)) p->handler(ext_int_code, param32, param64); - } + rcu_read_unlock(); irq_exit(); set_irq_regs(old_regs); } +void __init init_IRQ(void) +{ + init_external_interrupts(); +} + static DEFINE_SPINLOCK(sc_irq_lock); static int sc_irq_refcount; |