OpenCloudOS-Kernel/drivers/s390/cio/airq.c

86 lines
1.9 KiB
C

/*
* drivers/s390/cio/airq.c
* S/390 common I/O routines -- support for adapter interruptions
*
* Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
* IBM Corporation
* Author(s): Ingo Adlung (adlung@de.ibm.com)
* Cornelia Huck (cornelia.huck@de.ibm.com)
* Arnd Bergmann (arndb@de.ibm.com)
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include "cio_debug.h"
#include "airq.h"
static adapter_int_handler_t adapter_handler;
/*
* register for adapter interrupts
*
* With HiperSockets the zSeries architecture provides for
* means of adapter interrups, pseudo I/O interrupts that are
* not tied to an I/O subchannel, but to an adapter. However,
* it doesn't disclose the info how to enable/disable them, but
* to recognize them only. Perhaps we should consider them
* being shared interrupts, and thus build a linked list
* of adapter handlers ... to be evaluated ...
*/
int
s390_register_adapter_interrupt (adapter_int_handler_t handler)
{
int ret;
char dbf_txt[15];
CIO_TRACE_EVENT (4, "rgaint");
if (handler == NULL)
ret = -EINVAL;
else
ret = (cmpxchg(&adapter_handler, NULL, handler) ? -EBUSY : 0);
if (!ret)
synchronize_sched(); /* Allow interrupts to complete. */
sprintf (dbf_txt, "ret:%d", ret);
CIO_TRACE_EVENT (4, dbf_txt);
return ret;
}
int
s390_unregister_adapter_interrupt (adapter_int_handler_t handler)
{
int ret;
char dbf_txt[15];
CIO_TRACE_EVENT (4, "urgaint");
if (handler == NULL)
ret = -EINVAL;
else {
adapter_handler = NULL;
synchronize_sched(); /* Allow interrupts to complete. */
ret = 0;
}
sprintf (dbf_txt, "ret:%d", ret);
CIO_TRACE_EVENT (4, dbf_txt);
return ret;
}
void
do_adapter_IO (void)
{
CIO_TRACE_EVENT (6, "doaio");
if (adapter_handler)
(*adapter_handler) ();
}
EXPORT_SYMBOL (s390_register_adapter_interrupt);
EXPORT_SYMBOL (s390_unregister_adapter_interrupt);