linux/drivers/s390/cio/airq.c
Heiko Carstens 7d7c7b24e4 s390/bitops: rename find_first_bit_left() to find_first_bit_inv()
find_first_bit_left() and friends have nothing to do with the normal
LSB0 bit numbering for big endian machines used in Linux (least
significant bit has bit number 0).
Instead they use MSB0 bit numbering, where the most signficant bit has
bit number 0. So rename find_first_bit_left() and friends to
find_first_bit_inv(), to avoid any confusion.
Also provide inv versions of set_bit, clear_bit and test_bit.

This also removes the confusing use of e.g. set_bit() in airq.c which
uses a "be_to_le" bit number conversion, which could imply that instead
set_bit_le() could be used. But that is entirely wrong since the _le
bitops variant uses yet another bit numbering scheme.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24 17:16:56 +02:00

261 lines
6.2 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);
static irqreturn_t do_airq_interrupt(int irq, void *dummy)
{
struct tpi_info *tpi_info;
struct airq_struct *airq;
struct hlist_head *head;
__this_cpu_write(s390_idle.nohz_delay, 1);
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_bit - allocate an irq bit from an interrupt vector
* @iv: pointer to an interrupt vector structure
*
* Returns the bit number of the allocated irq, or -1UL if no bit
* is available or the AIRQ_IV_ALLOC flag has not been specified
*/
unsigned long airq_iv_alloc_bit(struct airq_iv *iv)
{
unsigned long bit;
if (!iv->avail)
return -1UL;
spin_lock(&iv->lock);
bit = find_first_bit_inv(iv->avail, iv->bits);
if (bit < iv->bits) {
clear_bit_inv(bit, iv->avail);
if (bit >= iv->end)
iv->end = bit + 1;
} else
bit = -1UL;
spin_unlock(&iv->lock);
return bit;
}
EXPORT_SYMBOL(airq_iv_alloc_bit);
/**
* airq_iv_free_bit - free an irq bit of an interrupt vector
* @iv: pointer to interrupt vector structure
* @bit: number of the irq bit to free
*/
void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit)
{
if (!iv->avail)
return;
spin_lock(&iv->lock);
/* Clear (possibly left over) interrupt bit */
clear_bit_inv(bit, iv->vector);
/* Make the bit position available again */
set_bit_inv(bit, iv->avail);
if (bit == iv->end - 1) {
/* Find new end of bit-field */
while (--iv->end > 0)
if (!test_bit_inv(iv->end - 1, iv->avail))
break;
}
spin_unlock(&iv->lock);
}
EXPORT_SYMBOL(airq_iv_free_bit);
/**
* 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);