[linux-2.6-block.git] / drivers / s390 / cio / airq.c

/*
 *    Support for adapter interruptions
 *
 *    Copyright IBM Corp. 1999, 2007
 *    Author(s): Ingo Adlung <adlung@de.ibm.com>
 *		 Cornelia Huck <cornelia.huck@de.ibm.com>
 *		 Arnd Bergmann <arndb@de.ibm.com>
 *		 Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
 */

#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <linux/slab.h>

#include <asm/airq.h>
#include <asm/isc.h>

#include "cio.h"
#include "cio_debug.h"
#include "ioasm.h"

static DEFINE_SPINLOCK(airq_lists_lock);
static struct hlist_head airq_lists[MAX_ISC+1];

/**
 * register_adapter_interrupt() - register adapter interrupt handler
 * @airq: pointer to adapter interrupt descriptor
 *
 * Returns 0 on success, or -EINVAL.
 */
int register_adapter_interrupt(struct airq_struct *airq)
{
	char dbf_txt[32];

	if (!airq->handler || airq->isc > MAX_ISC)
		return -EINVAL;
	if (!airq->lsi_ptr) {
		airq->lsi_ptr = kzalloc(1, GFP_KERNEL);
		if (!airq->lsi_ptr)
			return -ENOMEM;
		airq->flags |= AIRQ_PTR_ALLOCATED;
	}
	if (!airq->lsi_mask)
		airq->lsi_mask = 0xff;
	snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
	CIO_TRACE_EVENT(4, dbf_txt);
	isc_register(airq->isc);
	spin_lock(&airq_lists_lock);
	hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]);
	spin_unlock(&airq_lists_lock);
	return 0;
}
EXPORT_SYMBOL(register_adapter_interrupt);

/**
 * unregister_adapter_interrupt - unregister adapter interrupt handler
 * @airq: pointer to adapter interrupt descriptor
 */
void unregister_adapter_interrupt(struct airq_struct *airq)
{
	char dbf_txt[32];

	if (hlist_unhashed(&airq->list))
		return;
	snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq);
	CIO_TRACE_EVENT(4, dbf_txt);
	spin_lock(&airq_lists_lock);
	hlist_del_rcu(&airq->list);
	spin_unlock(&airq_lists_lock);
	synchronize_rcu();
	isc_unregister(airq->isc);
	if (airq->flags & AIRQ_PTR_ALLOCATED) {
		kfree(airq->lsi_ptr);
		airq->lsi_ptr = NULL;
		airq->flags &= ~AIRQ_PTR_ALLOCATED;
	}
}
EXPORT_SYMBOL(unregister_adapter_interrupt);

static irqreturn_t do_airq_interrupt(int irq, void *dummy)
{
	struct tpi_info *tpi_info;
	struct airq_struct *airq;
	struct hlist_head *head;

	set_cpu_flag(CIF_NOHZ_DELAY);
	tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
	head = &airq_lists[tpi_info->isc];
	rcu_read_lock();
	hlist_for_each_entry_rcu(airq, head, list)
		if ((*airq->lsi_ptr & airq->lsi_mask) != 0)
			airq->handler(airq);
	rcu_read_unlock();

	return IRQ_HANDLED;
}

static struct irqaction airq_interrupt = {
	.name	 = "AIO",
	.handler = do_airq_interrupt,
};

void __init init_airq_interrupts(void)
{
	irq_set_chip_and_handler(THIN_INTERRUPT,
				 &dummy_irq_chip, handle_percpu_irq);
	setup_irq(THIN_INTERRUPT, &airq_interrupt);
}

/**
 * airq_iv_create - create an interrupt vector
 * @bits: number of bits in the interrupt vector
 * @flags: allocation flags
 *
 * Returns a pointer to an interrupt vector structure
 */
struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)
{
	struct airq_iv *iv;
	unsigned long size;

	iv = kzalloc(sizeof(*iv), GFP_KERNEL);
	if (!iv)
		goto out;
	iv->bits = bits;
	size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
	iv->vector = kzalloc(size, GFP_KERNEL);
	if (!iv->vector)
		goto out_free;
	if (flags & AIRQ_IV_ALLOC) {
		iv->avail = kmalloc(size, GFP_KERNEL);
		if (!iv->avail)
			goto out_free;
		memset(iv->avail, 0xff, size);
		iv->end = 0;
	} else
		iv->end = bits;
	if (flags & AIRQ_IV_BITLOCK) {
		iv->bitlock = kzalloc(size, GFP_KERNEL);
		if (!iv->bitlock)
			goto out_free;
	}
	if (flags & AIRQ_IV_PTR) {
		size = bits * sizeof(unsigned long);
		iv->ptr = kzalloc(size, GFP_KERNEL);
		if (!iv->ptr)
			goto out_free;
	}
	if (flags & AIRQ_IV_DATA) {
		size = bits * sizeof(unsigned int);
		iv->data = kzalloc(size, GFP_KERNEL);
		if (!iv->data)
			goto out_free;
	}
	spin_lock_init(&iv->lock);
	return iv;

out_free:
	kfree(iv->ptr);
	kfree(iv->bitlock);
	kfree(iv->avail);
	kfree(iv->vector);
	kfree(iv);
out:
	return NULL;
}
EXPORT_SYMBOL(airq_iv_create);

/**
 * airq_iv_release - release an interrupt vector
 * @iv: pointer to interrupt vector structure
 */
void airq_iv_release(struct airq_iv *iv)
{
	kfree(iv->data);
	kfree(iv->ptr);
	kfree(iv->bitlock);
	kfree(iv->vector);
	kfree(iv->avail);
	kfree(iv);
}
EXPORT_SYMBOL(airq_iv_release);

/**
 * airq_iv_alloc - allocate irq bits from an interrupt vector
 * @iv: pointer to an interrupt vector structure
 * @num: number of consecutive irq bits to allocate
 *
 * Returns the bit number of the first irq in the allocated block of irqs,
 * or -1UL if no bit is available or the AIRQ_IV_ALLOC flag has not been
 * specified
 */
unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
{
	unsigned long bit, i, flags;

	if (!iv->avail || num == 0)
		return -1UL;
	spin_lock_irqsave(&iv->lock, flags);
	bit = find_first_bit_inv(iv->avail, iv->bits);
	while (bit + num <= iv->bits) {
		for (i = 1; i < num; i++)
			if (!test_bit_inv(bit + i, iv->avail))
				break;
		if (i >= num) {
			/* Found a suitable block of irqs */
			for (i = 0; i < num; i++)
				clear_bit_inv(bit + i, iv->avail);
			if (bit + num >= iv->end)
				iv->end = bit + num + 1;
			break;
		}
		bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1);
	}
	if (bit + num > iv->bits)
		bit = -1UL;
	spin_unlock_irqrestore(&iv->lock, flags);
	return bit;
}
EXPORT_SYMBOL(airq_iv_alloc);

/**
 * airq_iv_free - free irq bits of an interrupt vector
 * @iv: pointer to interrupt vector structure
 * @bit: number of the first irq bit to free
 * @num: number of consecutive irq bits to free
 */
void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
{
	unsigned long i, flags;

	if (!iv->avail || num == 0)
		return;
	spin_lock_irqsave(&iv->lock, flags);
	for (i = 0; i < num; i++) {
		/* Clear (possibly left over) interrupt bit */
		clear_bit_inv(bit + i, iv->vector);
		/* Make the bit positions available again */
		set_bit_inv(bit + i, iv->avail);
	}
	if (bit + num >= iv->end) {
		/* Find new end of bit-field */
		while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
			iv->end--;
	}
	spin_unlock_irqrestore(&iv->lock, flags);
}
EXPORT_SYMBOL(airq_iv_free);

/**
 * airq_iv_scan - scan interrupt vector for non-zero bits
 * @iv: pointer to interrupt vector structure
 * @start: bit number to start the search
 * @end: bit number to end the search
 *
 * Returns the bit number of the next non-zero interrupt bit, or
 * -1UL if the scan completed without finding any more any non-zero bits.
 */
unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
			   unsigned long end)
{
	unsigned long bit;

	/* Find non-zero bit starting from 'ivs->next'. */
	bit = find_next_bit_inv(iv->vector, end, start);
	if (bit >= end)
		return -1UL;
	clear_bit_inv(bit, iv->vector);
	return bit;
}
EXPORT_SYMBOL(airq_iv_scan);
Commit	Line	Data
1da177e4	1	/*
4e8e56c6	2	* Support for adapter interruptions
1da177e4	3	*
a53c8fab	4	* Copyright IBM Corp. 1999, 2007
4e8e56c6 PO	5	* Author(s): Ingo Adlung <adlung@de.ibm.com>
	6	* Cornelia Huck <cornelia.huck@de.ibm.com>
	7	* Arnd Bergmann <arndb@de.ibm.com>
	8	* Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
1da177e4 LT	9	*/
	10
	11	#include <linux/init.h>
f4eae94f MS	12	#include <linux/irq.h>
f4eae94f MS	13	#include <linux/kernel_stat.h>
1da177e4	14	#include <linux/module.h>
f4eae94f MS	15	#include <linux/mutex.h>
f4eae94f MS	16	#include <linux/rculist.h>
1da177e4	17	#include <linux/slab.h>
1da177e4	18
4e8e56c6	19	#include <asm/airq.h>
da7c5af8	20	#include <asm/isc.h>
4e8e56c6 PO	21
4e8e56c6 PO	22	#include "cio.h"
1da177e4	23	#include "cio_debug.h"
f4eae94f	24	#include "ioasm.h"
1da177e4	25
f4eae94f MS	26	static DEFINE_SPINLOCK(airq_lists_lock);
f4eae94f MS	27	static struct hlist_head airq_lists[MAX_ISC+1];
1da177e4	28
4e8e56c6	29	/**
f4eae94f MS	30	* register_adapter_interrupt() - register adapter interrupt handler
f4eae94f MS	31	* @airq: pointer to adapter interrupt descriptor
4e8e56c6	32	*
f4eae94f	33	* Returns 0 on success, or -EINVAL.
4e8e56c6	34	*/
f4eae94f	35	int register_adapter_interrupt(struct airq_struct *airq)
1da177e4	36	{
f4eae94f MS	37	char dbf_txt[32];
	38
	39	if (!airq->handler \|\| airq->isc > MAX_ISC)
	40	return -EINVAL;
	41	if (!airq->lsi_ptr) {
	42	airq->lsi_ptr = kzalloc(1, GFP_KERNEL);
	43	if (!airq->lsi_ptr)
	44	return -ENOMEM;
	45	airq->flags \|= AIRQ_PTR_ALLOCATED;
1da177e4	46	}
f4eae94f MS	47	if (!airq->lsi_mask)
	48	airq->lsi_mask = 0xff;
	49	snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
4e8e56c6	50	CIO_TRACE_EVENT(4, dbf_txt);
f4eae94f MS	51	isc_register(airq->isc);
	52	spin_lock(&airq_lists_lock);
	53	hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]);
	54	spin_unlock(&airq_lists_lock);
	55	return 0;
1da177e4	56	}
f4eae94f	57	EXPORT_SYMBOL(register_adapter_interrupt);
1da177e4	58
4e8e56c6	59	/**
f4eae94f MS	60	* unregister_adapter_interrupt - unregister adapter interrupt handler
f4eae94f MS	61	* @airq: pointer to adapter interrupt descriptor
4e8e56c6	62	*/
f4eae94f	63	void unregister_adapter_interrupt(struct airq_struct *airq)
1da177e4	64	{
f4eae94f	65	char dbf_txt[32];
1da177e4	66
f4eae94f MS	67	if (hlist_unhashed(&airq->list))
	68	return;
	69	snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq);
4e8e56c6	70	CIO_TRACE_EVENT(4, dbf_txt);
f4eae94f MS	71	spin_lock(&airq_lists_lock);
	72	hlist_del_rcu(&airq->list);
	73	spin_unlock(&airq_lists_lock);
	74	synchronize_rcu();
	75	isc_unregister(airq->isc);
	76	if (airq->flags & AIRQ_PTR_ALLOCATED) {
	77	kfree(airq->lsi_ptr);
	78	airq->lsi_ptr = NULL;
	79	airq->flags &= ~AIRQ_PTR_ALLOCATED;
	80	}
1da177e4	81	}
f4eae94f	82	EXPORT_SYMBOL(unregister_adapter_interrupt);
1da177e4	83
1f44a225	84	static irqreturn_t do_airq_interrupt(int irq, void *dummy)
4e8e56c6	85	{
1f44a225	86	struct tpi_info *tpi_info;
f4eae94f MS	87	struct airq_struct *airq;
	88	struct hlist_head *head;
	89
fe0f4976	90	set_cpu_flag(CIF_NOHZ_DELAY);
1f44a225 MS	91	tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
1f44a225 MS	92	head = &airq_lists[tpi_info->isc];
f4eae94f MS	93	rcu_read_lock();
	94	hlist_for_each_entry_rcu(airq, head, list)
	95	if ((*airq->lsi_ptr & airq->lsi_mask) != 0)
	96	airq->handler(airq);
	97	rcu_read_unlock();
1f44a225 MS	98
	99	return IRQ_HANDLED;
	100	}
	101
	102	static struct irqaction airq_interrupt = {
	103	.name = "AIO",
	104	.handler = do_airq_interrupt,
	105	};
	106
	107	void __init init_airq_interrupts(void)
	108	{
	109	irq_set_chip_and_handler(THIN_INTERRUPT,
	110	&dummy_irq_chip, handle_percpu_irq);
	111	setup_irq(THIN_INTERRUPT, &airq_interrupt);
4e8e56c6	112	}
a9a6f034 MS	113
	114	/**
	115	* airq_iv_create - create an interrupt vector
	116	* @bits: number of bits in the interrupt vector
	117	* @flags: allocation flags
	118	*
	119	* Returns a pointer to an interrupt vector structure
	120	*/
	121	struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)
	122	{
	123	struct airq_iv *iv;
	124	unsigned long size;
	125
	126	iv = kzalloc(sizeof(*iv), GFP_KERNEL);
	127	if (!iv)
	128	goto out;
	129	iv->bits = bits;
	130	size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
	131	iv->vector = kzalloc(size, GFP_KERNEL);
	132	if (!iv->vector)
	133	goto out_free;
	134	if (flags & AIRQ_IV_ALLOC) {
	135	iv->avail = kmalloc(size, GFP_KERNEL);
	136	if (!iv->avail)
	137	goto out_free;
	138	memset(iv->avail, 0xff, size);
	139	iv->end = 0;
	140	} else
	141	iv->end = bits;
	142	if (flags & AIRQ_IV_BITLOCK) {
	143	iv->bitlock = kzalloc(size, GFP_KERNEL);
	144	if (!iv->bitlock)
	145	goto out_free;
	146	}
	147	if (flags & AIRQ_IV_PTR) {
	148	size = bits * sizeof(unsigned long);
	149	iv->ptr = kzalloc(size, GFP_KERNEL);
	150	if (!iv->ptr)
	151	goto out_free;
	152	}
	153	if (flags & AIRQ_IV_DATA) {
	154	size = bits * sizeof(unsigned int);
	155	iv->data = kzalloc(size, GFP_KERNEL);
	156	if (!iv->data)
	157	goto out_free;
	158	}
	159	spin_lock_init(&iv->lock);
	160	return iv;
	161
	162	out_free:
	163	kfree(iv->ptr);
	164	kfree(iv->bitlock);
	165	kfree(iv->avail);
	166	kfree(iv->vector);
	167	kfree(iv);
	168	out:
	169	return NULL;
	170	}
	171	EXPORT_SYMBOL(airq_iv_create);
	172
	173	/**
	174	* airq_iv_release - release an interrupt vector
	175	* @iv: pointer to interrupt vector structure
	176	*/
177	void airq_iv_release(struct airq_iv *iv)
178	{
179	kfree(iv->data);
180	kfree(iv->ptr);
181	kfree(iv->bitlock);
182	kfree(iv->vector);
183	kfree(iv->avail);
184	kfree(iv);
185	}
186	EXPORT_SYMBOL(airq_iv_release);
187
188	/**
fe7c30a4	189	* airq_iv_alloc - allocate irq bits from an interrupt vector
a9a6f034	190	* @iv: pointer to an interrupt vector structure
fe7c30a4	191	* @num: number of consecutive irq bits to allocate
a9a6f034	192	*
fe7c30a4 MS	193	* Returns the bit number of the first irq in the allocated block of irqs,
	194	* or -1UL if no bit is available or the AIRQ_IV_ALLOC flag has not been
	195	* specified
a9a6f034	196	*/
fe7c30a4	197	unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
a9a6f034	198	{
0eb69a0c	199	unsigned long bit, i, flags;
a9a6f034	200
fe7c30a4	201	if (!iv->avail \|\| num == 0)
a9a6f034	202	return -1UL;
0eb69a0c	203	spin_lock_irqsave(&iv->lock, flags);
7d7c7b24	204	bit = find_first_bit_inv(iv->avail, iv->bits);
fe7c30a4 MS	205	while (bit + num <= iv->bits) {
	206	for (i = 1; i < num; i++)
	207	if (!test_bit_inv(bit + i, iv->avail))
	208	break;
	209	if (i >= num) {
	210	/* Found a suitable block of irqs */
	211	for (i = 0; i < num; i++)
	212	clear_bit_inv(bit + i, iv->avail);
	213	if (bit + num >= iv->end)
	214	iv->end = bit + num + 1;
	215	break;
	216	}
	217	bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1);
	218	}
	219	if (bit + num > iv->bits)
a9a6f034	220	bit = -1UL;
0eb69a0c	221	spin_unlock_irqrestore(&iv->lock, flags);
a9a6f034	222	return bit;
a9a6f034	223	}
fe7c30a4	224	EXPORT_SYMBOL(airq_iv_alloc);
a9a6f034 MS	225
a9a6f034 MS	226	/**
fe7c30a4	227	* airq_iv_free - free irq bits of an interrupt vector
a9a6f034	228	* @iv: pointer to interrupt vector structure
fe7c30a4 MS	229	* @bit: number of the first irq bit to free
fe7c30a4 MS	230	* @num: number of consecutive irq bits to free
a9a6f034	231	*/
fe7c30a4	232	void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
a9a6f034	233	{
0eb69a0c	234	unsigned long i, flags;
fe7c30a4 MS	235
fe7c30a4 MS	236	if (!iv->avail \|\| num == 0)
a9a6f034	237	return;
0eb69a0c	238	spin_lock_irqsave(&iv->lock, flags);
fe7c30a4 MS	239	for (i = 0; i < num; i++) {
	240	/* Clear (possibly left over) interrupt bit */
	241	clear_bit_inv(bit + i, iv->vector);
	242	/* Make the bit positions available again */
	243	set_bit_inv(bit + i, iv->avail);
	244	}
	245	if (bit + num >= iv->end) {
a9a6f034	246	/* Find new end of bit-field */
fe7c30a4 MS	247	while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
fe7c30a4 MS	248	iv->end--;
a9a6f034	249	}
0eb69a0c	250	spin_unlock_irqrestore(&iv->lock, flags);
a9a6f034	251	}
fe7c30a4	252	EXPORT_SYMBOL(airq_iv_free);
a9a6f034 MS	253
	254	/**
	255	* airq_iv_scan - scan interrupt vector for non-zero bits
	256	* @iv: pointer to interrupt vector structure
	257	* @start: bit number to start the search
	258	* @end: bit number to end the search
	259	*
	260	* Returns the bit number of the next non-zero interrupt bit, or
	261	* -1UL if the scan completed without finding any more any non-zero bits.
	262	*/
	263	unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
	264	unsigned long end)
	265	{
a9a6f034 MS	266	unsigned long bit;
	267
	268	/* Find non-zero bit starting from 'ivs->next'. */
7d7c7b24	269	bit = find_next_bit_inv(iv->vector, end, start);
a9a6f034 MS	270	if (bit >= end)
a9a6f034 MS	271	return -1UL;
7d7c7b24	272	clear_bit_inv(bit, iv->vector);
a9a6f034 MS	273	return bit;
	274	}
	275	EXPORT_SYMBOL(airq_iv_scan);