[net-next-2.6.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/ftrace.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <asm/cputime.h>
#include <asm/lowcore.h>
#include <asm/s390_ext.h>
#include <asm/irq_regs.h>
#include <asm/irq.h>
#include "entry.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 __irq_entry 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);
	s390_idle_check();
	irq_enter();
	if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
		/* Serve timer interrupts first. */
		clock_comparator_work();
	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))
			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>
88dbd203	13	#include <linux/ftrace.h>
1da177e4 LT	14	#include <linux/errno.h>
	15	#include <linux/kernel_stat.h>
	16	#include <linux/interrupt.h>
76d4e00a	17	#include <asm/cputime.h>
1da177e4 LT	18	#include <asm/lowcore.h>
1da177e4 LT	19	#include <asm/s390_ext.h>
5a489b98	20	#include <asm/irq_regs.h>
1da177e4	21	#include <asm/irq.h>
a806170e	22	#include "entry.h"
1da177e4 LT	23
1da177e4 LT	24	/*
1da177e4 LT	25	* 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	*/
d2c993d8	30	ext_int_info_t *ext_int_hash[256] = { NULL, };
1da177e4	31
99b2d8df HC	32	static inline int ext_hash(__u16 code)
	33	{
	34	return (code + (code >> 9)) & 0xff;
	35	}
	36
1da177e4 LT	37	int register_external_interrupt(__u16 code, ext_int_handler_t handler)
	38	{
	39	ext_int_info_t *p;
	40	int index;
	41
5cbded58	42	p = kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
1da177e4 LT	43	if (p == NULL)
	44	return -ENOMEM;
	45	p->code = code;
	46	p->handler = handler;
99b2d8df	47	index = ext_hash(code);
1da177e4 LT	48	p->next = ext_int_hash[index];
	49	ext_int_hash[index] = p;
	50	return 0;
	51	}
	52
	53	int 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;
99b2d8df	62	index = ext_hash(code);
1da177e4 LT	63	p->next = ext_int_hash[index];
	64	ext_int_hash[index] = p;
	65	return 0;
	66	}
	67
	68	int unregister_external_interrupt(__u16 code, ext_int_handler_t handler)
	69	{
	70	ext_int_info_t p, q;
	71	int index;
	72
99b2d8df	73	index = ext_hash(code);
1da177e4 LT	74	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
	92	int 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;
99b2d8df	100	index = ext_hash(code);
1da177e4 LT	101	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
88dbd203	116	void __irq_entry do_extint(struct pt_regs *regs, unsigned short code)
1da177e4 LT	117	{
	118	ext_int_info_t *p;
	119	int index;
5a489b98	120	struct pt_regs *old_regs;
1da177e4	121
5a489b98	122	old_regs = set_irq_regs(regs);
43ca5c3a	123	s390_idle_check();
9cfb9b3c	124	irq_enter();
5a62b192 HC	125	if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
	126	/* Serve timer interrupts first. */
	127	clock_comparator_work();
1da177e4	128	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
99b2d8df	129	index = ext_hash(code);
1da177e4	130	for (p = ext_int_hash[index]; p; p = p->next) {
d54853ef MS	131	if (likely(p->code == code))
d54853ef MS	132	p->handler(code);
1da177e4 LT	133	}
1da177e4 LT	134	irq_exit();
9d0a57cb	135	set_irq_regs(old_regs);
1da177e4 LT	136	}
	137
	138	EXPORT_SYMBOL(register_external_interrupt);
	139	EXPORT_SYMBOL(unregister_external_interrupt);