da7c5af828
Enhance the adapter interruption API so that device drivers can register a handler for a specific interruption subclass. This will allow different device drivers to move to differently prioritized subclasses in order to avoid congestion. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
150 lines
3.4 KiB
C
150 lines
3.4 KiB
C
/*
|
|
* 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/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/rcupdate.h>
|
|
|
|
#include <asm/airq.h>
|
|
#include <asm/isc.h>
|
|
|
|
#include "cio.h"
|
|
#include "cio_debug.h"
|
|
|
|
#define NR_AIRQS 32
|
|
#define NR_AIRQS_PER_WORD sizeof(unsigned long)
|
|
#define NR_AIRQ_WORDS (NR_AIRQS / NR_AIRQS_PER_WORD)
|
|
|
|
union indicator_t {
|
|
unsigned long word[NR_AIRQ_WORDS];
|
|
unsigned char byte[NR_AIRQS];
|
|
} __attribute__((packed));
|
|
|
|
struct airq_t {
|
|
adapter_int_handler_t handler;
|
|
void *drv_data;
|
|
};
|
|
|
|
static union indicator_t indicators[MAX_ISC];
|
|
static struct airq_t *airqs[MAX_ISC][NR_AIRQS];
|
|
|
|
static int register_airq(struct airq_t *airq, u8 isc)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NR_AIRQS; i++)
|
|
if (!cmpxchg(&airqs[isc][i], NULL, airq))
|
|
return i;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/**
|
|
* s390_register_adapter_interrupt() - register adapter interrupt handler
|
|
* @handler: adapter handler to be registered
|
|
* @drv_data: driver data passed with each call to the handler
|
|
* @isc: isc for which the handler should be called
|
|
*
|
|
* Returns:
|
|
* Pointer to the indicator to be used on success
|
|
* ERR_PTR() if registration failed
|
|
*/
|
|
void *s390_register_adapter_interrupt(adapter_int_handler_t handler,
|
|
void *drv_data, u8 isc)
|
|
{
|
|
struct airq_t *airq;
|
|
char dbf_txt[16];
|
|
int ret;
|
|
|
|
if (isc > MAX_ISC)
|
|
return ERR_PTR(-EINVAL);
|
|
airq = kmalloc(sizeof(struct airq_t), GFP_KERNEL);
|
|
if (!airq) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
airq->handler = handler;
|
|
airq->drv_data = drv_data;
|
|
|
|
ret = register_airq(airq, isc);
|
|
out:
|
|
snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%d", ret);
|
|
CIO_TRACE_EVENT(4, dbf_txt);
|
|
if (ret < 0) {
|
|
kfree(airq);
|
|
return ERR_PTR(ret);
|
|
} else
|
|
return &indicators[isc].byte[ret];
|
|
}
|
|
EXPORT_SYMBOL(s390_register_adapter_interrupt);
|
|
|
|
/**
|
|
* s390_unregister_adapter_interrupt - unregister adapter interrupt handler
|
|
* @ind: indicator for which the handler is to be unregistered
|
|
* @isc: interruption subclass
|
|
*/
|
|
void s390_unregister_adapter_interrupt(void *ind, u8 isc)
|
|
{
|
|
struct airq_t *airq;
|
|
char dbf_txt[16];
|
|
int i;
|
|
|
|
i = (int) ((addr_t) ind) - ((addr_t) &indicators[isc].byte[0]);
|
|
snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%d", i);
|
|
CIO_TRACE_EVENT(4, dbf_txt);
|
|
indicators[isc].byte[i] = 0;
|
|
airq = xchg(&airqs[isc][i], NULL);
|
|
/*
|
|
* Allow interrupts to complete. This will ensure that the airq handle
|
|
* is no longer referenced by any interrupt handler.
|
|
*/
|
|
synchronize_sched();
|
|
kfree(airq);
|
|
}
|
|
EXPORT_SYMBOL(s390_unregister_adapter_interrupt);
|
|
|
|
#define INDICATOR_MASK (0xffUL << ((NR_AIRQS_PER_WORD - 1) * 8))
|
|
|
|
void do_adapter_IO(u8 isc)
|
|
{
|
|
int w;
|
|
int i;
|
|
unsigned long word;
|
|
struct airq_t *airq;
|
|
|
|
/*
|
|
* Access indicator array in word-sized chunks to minimize storage
|
|
* fetch operations.
|
|
*/
|
|
for (w = 0; w < NR_AIRQ_WORDS; w++) {
|
|
word = indicators[isc].word[w];
|
|
i = w * NR_AIRQS_PER_WORD;
|
|
/*
|
|
* Check bytes within word for active indicators.
|
|
*/
|
|
while (word) {
|
|
if (word & INDICATOR_MASK) {
|
|
airq = airqs[isc][i];
|
|
if (likely(airq))
|
|
airq->handler(&indicators[isc].byte[i],
|
|
airq->drv_data);
|
|
else
|
|
/*
|
|
* Reset ill-behaved indicator.
|
|
*/
|
|
indicators[isc].byte[i] = 0;
|
|
}
|
|
word <<= 8;
|
|
i++;
|
|
}
|
|
}
|
|
}
|