[linux-2.6-block.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_regs.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] = { NULL, };

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 = 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;
	struct pt_regs *old_regs;

	old_regs = set_irq_regs(regs);
	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();
	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(code);
		}
	}
	irq_exit();
	set_irq_regs(old_regs);
}

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>
5a489b98	19	#include <asm/irq_regs.h>
1da177e4 LT	20	#include <asm/irq.h>
	21
	22	/*
1da177e4 LT	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	*/
d2c993d8	28	ext_int_info_t *ext_int_hash[256] = { NULL, };
1da177e4	29
99b2d8df HC	30	static inline int ext_hash(__u16 code)
	31	{
	32	return (code + (code >> 9)) & 0xff;
	33	}
	34
1da177e4 LT	35	int register_external_interrupt(__u16 code, ext_int_handler_t handler)
	36	{
	37	ext_int_info_t *p;
	38	int index;
	39
5cbded58	40	p = kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
1da177e4 LT	41	if (p == NULL)
	42	return -ENOMEM;
	43	p->code = code;
	44	p->handler = handler;
99b2d8df	45	index = ext_hash(code);
1da177e4 LT	46	p->next = ext_int_hash[index];
	47	ext_int_hash[index] = p;
	48	return 0;
	49	}
	50
	51	int register_early_external_interrupt(__u16 code, ext_int_handler_t handler,
	52	ext_int_info_t *p)
	53	{
	54	int index;
	55
	56	if (p == NULL)
	57	return -EINVAL;
	58	p->code = code;
	59	p->handler = handler;
99b2d8df	60	index = ext_hash(code);
1da177e4 LT	61	p->next = ext_int_hash[index];
	62	ext_int_hash[index] = p;
	63	return 0;
	64	}
	65
	66	int unregister_external_interrupt(__u16 code, ext_int_handler_t handler)
	67	{
	68	ext_int_info_t p, q;
	69	int index;
	70
99b2d8df	71	index = ext_hash(code);
1da177e4 LT	72	q = NULL;
	73	p = ext_int_hash[index];
	74	while (p != NULL) {
	75	if (p->code == code && p->handler == handler)
	76	break;
	77	q = p;
	78	p = p->next;
	79	}
	80	if (p == NULL)
	81	return -ENOENT;
	82	if (q != NULL)
	83	q->next = p->next;
	84	else
	85	ext_int_hash[index] = p->next;
	86	kfree(p);
	87	return 0;
	88	}
	89
	90	int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler,
	91	ext_int_info_t *p)
	92	{
	93	ext_int_info_t *q;
	94	int index;
	95
	96	if (p == NULL \|\| p->code != code \|\| p->handler != handler)
	97	return -EINVAL;
99b2d8df	98	index = ext_hash(code);
1da177e4 LT	99	q = ext_int_hash[index];
	100	if (p != q) {
	101	while (q != NULL) {
	102	if (q->next == p)
	103	break;
	104	q = q->next;
	105	}
	106	if (q == NULL)
	107	return -ENOENT;
	108	q->next = p->next;
	109	} else
	110	ext_int_hash[index] = p->next;
	111	return 0;
	112	}
	113
	114	void do_extint(struct pt_regs *regs, unsigned short code)
	115	{
	116	ext_int_info_t *p;
	117	int index;
5a489b98	118	struct pt_regs *old_regs;
1da177e4	119
5a489b98	120	old_regs = set_irq_regs(regs);
9d0a57cb	121	irq_enter();
1da177e4 LT	122	asm volatile ("mc 0,0");
	123	if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
	124	/**
	125	* Make sure that the i/o interrupt did not "overtake"
	126	* the last HZ timer interrupt.
	127	*/
5a489b98	128	account_ticks();
1da177e4	129	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
99b2d8df	130	index = ext_hash(code);
1da177e4 LT	131	for (p = ext_int_hash[index]; p; p = p->next) {
	132	if (likely(p->code == code)) {
	133	if (likely(p->handler))
5a489b98	134	p->handler(code);
1da177e4 LT	135	}
	136	}
	137	irq_exit();
9d0a57cb	138	set_irq_regs(old_regs);
1da177e4 LT	139	}
	140
	141	EXPORT_SYMBOL(register_external_interrupt);
	142	EXPORT_SYMBOL(unregister_external_interrupt);