[people/ms/linux.git] / arch / s390 / kernel / s390_ext.c

/*
 *  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>

/*
 * 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, };

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 = code & 0xff;
        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 = code & 0xff;
        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;
	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 = code & 0xff;
	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 = code & 0xff;
	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);
Commit	Line	Data
1da177e4 LT	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 <linux/errno.h>
	14	#include <linux/kernel_stat.h>
	15	#include <linux/interrupt.h>
	16
	17	#include <asm/lowcore.h>
	18	#include <asm/s390_ext.h>
	19	#include <asm/irq.h>
	20
	21	/*
	22	* Simple hash strategy: index = code & 0xff;
	23	* ext_int_hash[index] is the start of the list for all external interrupts
	24	* that hash to this index. With the current set of external interrupts
	25	* (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000
	26	* iucv and 0x2603 pfault) this is always the first element.
	27	*/
	28	ext_int_info_t *ext_int_hash[256] = { 0, };
	29
	30	int register_external_interrupt(__u16 code, ext_int_handler_t handler)
	31	{
	32	ext_int_info_t *p;
	33	int index;
	34
	35	p = (ext_int_info_t *) kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
	36	if (p == NULL)
	37	return -ENOMEM;
	38	p->code = code;
	39	p->handler = handler;
	40	index = code & 0xff;
	41	p->next = ext_int_hash[index];
	42	ext_int_hash[index] = p;
	43	return 0;
	44	}
	45
	46	int register_early_external_interrupt(__u16 code, ext_int_handler_t handler,
	47	ext_int_info_t *p)
	48	{
	49	int index;
	50
	51	if (p == NULL)
	52	return -EINVAL;
	53	p->code = code;
	54	p->handler = handler;
	55	index = code & 0xff;
	56	p->next = ext_int_hash[index];
	57	ext_int_hash[index] = p;
	58	return 0;
	59	}
	60
	61	int unregister_external_interrupt(__u16 code, ext_int_handler_t handler)
	62	{
	63	ext_int_info_t p, q;
	64	int index;
65
66	index = code & 0xff;
67	q = NULL;
68	p = ext_int_hash[index];
69	while (p != NULL) {
70	if (p->code == code && p->handler == handler)
71	break;
72	q = p;
73	p = p->next;
74	}
75	if (p == NULL)
76	return -ENOENT;
77	if (q != NULL)
78	q->next = p->next;
79	else
80	ext_int_hash[index] = p->next;
81	kfree(p);
82	return 0;
83	}
84
85	int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler,
86	ext_int_info_t *p)
87	{
88	ext_int_info_t *q;
89	int index;
90
91	if (p == NULL \|\| p->code != code \|\| p->handler != handler)
92	return -EINVAL;
93	index = code & 0xff;
94	q = ext_int_hash[index];
95	if (p != q) {
96	while (q != NULL) {
97	if (q->next == p)
98	break;
99	q = q->next;
100	}
101	if (q == NULL)
102	return -ENOENT;
103	q->next = p->next;
104	} else
105	ext_int_hash[index] = p->next;
106	return 0;
107	}
108
109	void do_extint(struct pt_regs *regs, unsigned short code)
110	{
111	ext_int_info_t *p;
112	int index;
113
114	irq_enter();
115	asm volatile ("mc 0,0");
116	if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
117	/**
118	* Make sure that the i/o interrupt did not "overtake"
119	* the last HZ timer interrupt.
120	*/
121	account_ticks(regs);
122	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
123	index = code & 0xff;
124	for (p = ext_int_hash[index]; p; p = p->next) {
125	if (likely(p->code == code)) {
126	if (likely(p->handler))
127	p->handler(regs, code);
128	}
129	}
130	irq_exit();
131	}
132
133	EXPORT_SYMBOL(register_external_interrupt);
134	EXPORT_SYMBOL(unregister_external_interrupt);
135