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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 <asm/lowcore.h>
#include <asm/s390_ext.h>
/*
* Simple hash strategy: index = code & 0xff;
* 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, };
ext_int_info_t ext_int_info_timer;
ext_int_info_t ext_int_info_hwc;
ext_int_info_t ext_int_pfault;
int register_external_interrupt(__u16 code, ext_int_handler_t handler) {
ext_int_info_t *p;
int index;
index = code & 0xff;
p = ext_int_hash[index];
while (p != NULL) {
if (p->code == code)
return -EBUSY;
p = p->next;
}
if (code == 0x1004) /* time_init is done before kmalloc works :-/ */
p = &ext_int_info_timer;
else if (code == 0x2401) /* hwc_init is done too early too */
p = &ext_int_info_hwc;
else if (code == 0x2603) /* pfault_init is done too early too */
p = &ext_int_pfault;
else
p = (ext_int_info_t *)
kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
if (p == NULL)
return -ENOMEM;
p->code = code;
p->handler = handler;
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 = code & 0xff;
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;
if (code != 0x1004 && code != 0x2401 && code != 0x2603)
kfree(p);
return 0;
}
EXPORT_SYMBOL(register_external_interrupt);
EXPORT_SYMBOL(unregister_external_interrupt);
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