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/*
* 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);
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