blob: 0de305b598cee30a1352f67d4ded1eda4f0d3be0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Heiko Carstens88dbd202009-06-12 10:26:46 +020013#include <linux/ftrace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/errno.h>
15#include <linux/kernel_stat.h>
16#include <linux/interrupt.h>
Martin Schwidefsky76d4e002009-06-12 10:26:21 +020017#include <asm/cputime.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <asm/lowcore.h>
19#include <asm/s390_ext.h>
Heiko Carstens5a489b92006-10-06 16:38:35 +020020#include <asm/irq_regs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <asm/irq.h>
Heiko Carstensa8061702008-04-17 07:46:26 +020022#include "entry.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
24/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 * ext_int_hash[index] is the start of the list for all external interrupts
26 * that hash to this index. With the current set of external interrupts
27 * (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000
28 * iucv and 0x2603 pfault) this is always the first element.
29 */
Heiko Carstensd2c993d2006-07-12 16:41:55 +020030ext_int_info_t *ext_int_hash[256] = { NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
Heiko Carstens99b2d8d2005-07-27 11:45:00 -070032static inline int ext_hash(__u16 code)
33{
34 return (code + (code >> 9)) & 0xff;
35}
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037int register_external_interrupt(__u16 code, ext_int_handler_t handler)
38{
39 ext_int_info_t *p;
40 int index;
41
Robert P. J. Day5cbded52006-12-13 00:35:56 -080042 p = kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 if (p == NULL)
44 return -ENOMEM;
45 p->code = code;
46 p->handler = handler;
Heiko Carstens99b2d8d2005-07-27 11:45:00 -070047 index = ext_hash(code);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 p->next = ext_int_hash[index];
49 ext_int_hash[index] = p;
50 return 0;
51}
52
53int register_early_external_interrupt(__u16 code, ext_int_handler_t handler,
54 ext_int_info_t *p)
55{
56 int index;
57
58 if (p == NULL)
59 return -EINVAL;
60 p->code = code;
61 p->handler = handler;
Heiko Carstens99b2d8d2005-07-27 11:45:00 -070062 index = ext_hash(code);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 p->next = ext_int_hash[index];
64 ext_int_hash[index] = p;
65 return 0;
66}
67
68int unregister_external_interrupt(__u16 code, ext_int_handler_t handler)
69{
70 ext_int_info_t *p, *q;
71 int index;
72
Heiko Carstens99b2d8d2005-07-27 11:45:00 -070073 index = ext_hash(code);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 q = NULL;
75 p = ext_int_hash[index];
76 while (p != NULL) {
77 if (p->code == code && p->handler == handler)
78 break;
79 q = p;
80 p = p->next;
81 }
82 if (p == NULL)
83 return -ENOENT;
84 if (q != NULL)
85 q->next = p->next;
86 else
87 ext_int_hash[index] = p->next;
88 kfree(p);
89 return 0;
90}
91
92int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler,
93 ext_int_info_t *p)
94{
95 ext_int_info_t *q;
96 int index;
97
98 if (p == NULL || p->code != code || p->handler != handler)
99 return -EINVAL;
Heiko Carstens99b2d8d2005-07-27 11:45:00 -0700100 index = ext_hash(code);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 q = ext_int_hash[index];
102 if (p != q) {
103 while (q != NULL) {
104 if (q->next == p)
105 break;
106 q = q->next;
107 }
108 if (q == NULL)
109 return -ENOENT;
110 q->next = p->next;
111 } else
112 ext_int_hash[index] = p->next;
113 return 0;
114}
115
Heiko Carstens88dbd202009-06-12 10:26:46 +0200116void __irq_entry do_extint(struct pt_regs *regs, unsigned short code)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117{
118 ext_int_info_t *p;
119 int index;
Heiko Carstens5a489b92006-10-06 16:38:35 +0200120 struct pt_regs *old_regs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Heiko Carstens5a489b92006-10-06 16:38:35 +0200122 old_regs = set_irq_regs(regs);
Heiko Carstens43ca5c32008-04-17 07:46:23 +0200123 s390_idle_check();
Martin Schwidefsky9cfb9b32008-12-31 15:11:41 +0100124 irq_enter();
Heiko Carstens5a62b192008-04-17 07:46:25 +0200125 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
126 /* Serve timer interrupts first. */
127 clock_comparator_work();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
Heiko Carstens99b2d8d2005-07-27 11:45:00 -0700129 index = ext_hash(code);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 for (p = ext_int_hash[index]; p; p = p->next) {
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100131 if (likely(p->code == code))
132 p->handler(code);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 }
134 irq_exit();
Heiko Carstens9d0a57c2006-10-11 15:31:26 +0200135 set_irq_regs(old_regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136}
137
138EXPORT_SYMBOL(register_external_interrupt);
139EXPORT_SYMBOL(unregister_external_interrupt);