1 /*
2 * arch/s390/kernel/s390_ext.c
3 *
4 * S390 version
5 * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Holger Smolinski (Holger.Smolinski@de.ibm.com),
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
8 */
9
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <asm/lowcore.h>
14 #include <asm/s390_ext.h>
15
16 /*
17 * Simple hash strategy: index = code & 0xff;
18 * ext_int_hash[index] is the start of the list for all external interrupts
19 * that hash to this index. With the current set of external interrupts
20 * (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000
21 * iucv and 0x2603 pfault) this is always the first element.
22 */
23 ext_int_info_t *ext_int_hash[256] = { 0, };
24
register_external_interrupt(__u16 code,ext_int_handler_t handler)25 int register_external_interrupt(__u16 code, ext_int_handler_t handler) {
26 ext_int_info_t *p;
27 int index;
28
29 p = (ext_int_info_t *) kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
30 if (p == NULL)
31 return -ENOMEM;
32 p->code = code;
33 p->handler = handler;
34 index = code & 0xff;
35 p->next = ext_int_hash[index];
36 ext_int_hash[index] = p;
37 return 0;
38 }
39
register_early_external_interrupt(__u16 code,ext_int_handler_t handler,ext_int_info_t * p)40 int register_early_external_interrupt(__u16 code, ext_int_handler_t handler,
41 ext_int_info_t *p) {
42 int index;
43
44 if (p == NULL)
45 return -EINVAL;
46 p->code = code;
47 p->handler = handler;
48 index = code & 0xff;
49 p->next = ext_int_hash[index];
50 ext_int_hash[index] = p;
51 return 0;
52 }
53
unregister_external_interrupt(__u16 code,ext_int_handler_t handler)54 int unregister_external_interrupt(__u16 code, ext_int_handler_t handler) {
55 ext_int_info_t *p, *q;
56 int index;
57
58 index = code & 0xff;
59 q = NULL;
60 p = ext_int_hash[index];
61 while (p != NULL) {
62 if (p->code == code && p->handler == handler)
63 break;
64 q = p;
65 p = p->next;
66 }
67 if (p == NULL)
68 return -ENOENT;
69 if (q != NULL)
70 q->next = p->next;
71 else
72 ext_int_hash[index] = p->next;
73 kfree(p);
74 return 0;
75 }
76
unregister_early_external_interrupt(__u16 code,ext_int_handler_t handler,ext_int_info_t * p)77 int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler,
78 ext_int_info_t *p) {
79 ext_int_info_t *q;
80 int index;
81
82 if (p == NULL || p->code != code || p->handler != handler)
83 return -EINVAL;
84 index = code & 0xff;
85 q = ext_int_hash[index];
86 if (p != q) {
87 while (q != NULL) {
88 if (q->next == p)
89 break;
90 q = q->next;
91 }
92 if (q == NULL)
93 return -ENOENT;
94 q->next = p->next;
95 } else
96 ext_int_hash[index] = p->next;
97 return 0;
98 }
99
100 EXPORT_SYMBOL(register_external_interrupt);
101 EXPORT_SYMBOL(unregister_external_interrupt);
102
103