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/*
* arch/s390/kernel/s390_ext.c
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Holger Smolinski (Holger.Smolinski@de.ibm.com),
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <asm/lowcore.h>
#include <asm/s390_ext.h>
#include <asm/irq.h>
/*
* 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_info_t *ext_int_hash[256] = { 0, };
static inline int ext_hash(__u16 code)
{
return (code + (code >> 9)) & 0xff;
}
int register_external_interrupt(__u16 code, ext_int_handler_t handler)
{
ext_int_info_t *p;
int index;
p = (ext_int_info_t *) kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
if (p == NULL)
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;
}
int register_early_external_interrupt(__u16 code, ext_int_handler_t handler,
ext_int_info_t *p)
{
int index;
if (p == NULL)
return -EINVAL;
p->code = code;
p->handler = handler;
index = ext_hash(code);
p->next = ext_int_hash[index];
ext_int_hash[index] = p;
return 0;
}
int unregister_external_interrupt(__u16 code, ext_int_handler_t handler)
{
ext_int_info_t *p, *q;
int index;
index = ext_hash(code);
q = NULL;
p = ext_int_hash[index];
while (p != NULL) {
if (p->code == code && p->handler == handler)
break;
q = p;
p = p->next;
}
if (p == NULL)
return -ENOENT;
if (q != NULL)
q->next = p->next;
else
ext_int_hash[index] = p->next;
kfree(p);
return 0;
}
int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler,
ext_int_info_t *p)
{
ext_int_info_t *q;
int index;
if (p == NULL || p->code != code || p->handler != handler)
return -EINVAL;
index = ext_hash(code);
q = ext_int_hash[index];
if (p != q) {
while (q != NULL) {
if (q->next == p)
break;
q = q->next;
}
if (q == NULL)
return -ENOENT;
q->next = p->next;
} else
ext_int_hash[index] = p->next;
return 0;
}
void do_extint(struct pt_regs *regs, unsigned short code)
{
ext_int_info_t *p;
int index;
irq_enter();
asm volatile ("mc 0,0");
if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
/**
* Make sure that the i/o interrupt did not "overtake"
* the last HZ timer interrupt.
*/
account_ticks(regs);
kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
index = ext_hash(code);
for (p = ext_int_hash[index]; p; p = p->next) {
if (likely(p->code == code)) {
if (likely(p->handler))
p->handler(regs, code);
}
}
irq_exit();
}
EXPORT_SYMBOL(register_external_interrupt);
EXPORT_SYMBOL(unregister_external_interrupt);
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