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linux-next/drivers/s390/cio/airq.c
Martin Schwidefsky f4eae94f71 s390/airq: simplify adapter interrupt code
There are three users of adapter interrupts: AP, QDIO and PCI. Each
registers a single adapter interrupt with independent ISCs. Define
a "struct airq" with the interrupt handler, a pointer and a mask for
the local summary indicator and the ISC for the adapter interrupt
source. Convert the indicator array with its fixed number of adapter
interrupt sources per ISE to an array of hlists. This removes the
limitation to 32 adapter interrupts per ISC and allows for arbitrary
memory locations for the local summary indicator.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-06-26 21:10:28 +02:00

96 lines
2.3 KiB
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);
void do_adapter_IO(u8 isc)
{
struct airq_struct *airq;
struct hlist_head *head;
head = &airq_lists[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();
}