-/*
- * Copyright IBM Corp. 1999,2010
- * Author(s): Holger Smolinski <Holger.Smolinski@de.ibm.com>,
- * Martin Schwidefsky <schwidefsky@de.ibm.com>,
- */
-
-#include <linux/kernel_stat.h>
-#include <linux/interrupt.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/ftrace.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <asm/s390_ext.h>
-#include <asm/irq_regs.h>
-#include <asm/cputime.h>
-#include <asm/lowcore.h>
-#include <asm/irq.h>
-#include "entry.h"
-
-struct ext_int_info {
- struct ext_int_info *next;
- ext_int_handler_t handler;
- __u16 code;
-};
-
-/*
- * 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.
- */
-static struct ext_int_info *ext_int_hash[256];
-
-static inline int ext_hash(__u16 code)
-{
- return (code + (code >> 9)) & 0xff;
-}
-
-int register_external_interrupt(__u16 code, ext_int_handler_t handler)
-{
- struct ext_int_info *p;
- int index;
-
- p = kmalloc(sizeof(*p), GFP_ATOMIC);
- if (!p)
- return -ENOMEM;
- p->code = code;
- p->handler = handler;
- index = ext_hash(code);
- p->next = ext_int_hash[index];
- ext_int_hash[index] = p;
- 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;
-
- 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);
- return 0;
-}
-EXPORT_SYMBOL(unregister_external_interrupt);
-
-void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code,
- unsigned int param32, unsigned long param64)
-{
- struct pt_regs *old_regs;
- unsigned short code;
- struct ext_int_info *p;
- int index;
-
- code = (unsigned short) ext_int_code;
- old_regs = set_irq_regs(regs);
- s390_idle_check(regs, S390_lowcore.int_clock,
- S390_lowcore.async_enter_timer);
- irq_enter();
- if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
- /* Serve timer interrupts first. */
- clock_comparator_work();
- 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) {
- if (likely(p->code == code))
- p->handler(ext_int_code, param32, param64);
- }
- irq_exit();
- set_irq_regs(old_regs);
-}
-
-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);