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/*
* 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);
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