s390/airq: introduce adapter interrupt vector helper

The PCI code is the first user of adapter interrupts vectors.
Add a set of helpers to airq.c to separate the adatper interrupt
code from the PCI bits. The helpers allow for adapter interrupt
vectors of any size.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2013-06-25 14:17:57 +02:00
parent 0ea46b0e37
commit a9a6f0341d
2 changed files with 220 additions and 0 deletions

View File

@ -9,6 +9,8 @@
#ifndef _ASM_S390_AIRQ_H
#define _ASM_S390_AIRQ_H
#include <linux/bit_spinlock.h>
struct airq_struct {
struct hlist_node list; /* Handler queueing. */
void (*handler)(struct airq_struct *); /* Thin-interrupt handler */
@ -23,4 +25,69 @@ struct airq_struct {
int register_adapter_interrupt(struct airq_struct *airq);
void unregister_adapter_interrupt(struct airq_struct *airq);
/* Adapter interrupt bit vector */
struct airq_iv {
unsigned long *vector; /* Adapter interrupt bit vector */
unsigned long *avail; /* Allocation bit mask for the bit vector */
unsigned long *bitlock; /* Lock bit mask for the bit vector */
unsigned long *ptr; /* Pointer associated with each bit */
unsigned int *data; /* 32 bit value associated with each bit */
unsigned long bits; /* Number of bits in the vector */
unsigned long end; /* Number of highest allocated bit + 1 */
spinlock_t lock; /* Lock to protect alloc & free */
};
#define AIRQ_IV_ALLOC 1 /* Use an allocation bit mask */
#define AIRQ_IV_BITLOCK 2 /* Allocate the lock bit mask */
#define AIRQ_IV_PTR 4 /* Allocate the ptr array */
#define AIRQ_IV_DATA 8 /* Allocate the data array */
struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags);
void airq_iv_release(struct airq_iv *iv);
unsigned long airq_iv_alloc_bit(struct airq_iv *iv);
void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit);
unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
unsigned long end);
static inline unsigned long airq_iv_end(struct airq_iv *iv)
{
return iv->end;
}
static inline void airq_iv_lock(struct airq_iv *iv, unsigned long bit)
{
const unsigned long be_to_le = BITS_PER_LONG - 1;
bit_spin_lock(bit ^ be_to_le, iv->bitlock);
}
static inline void airq_iv_unlock(struct airq_iv *iv, unsigned long bit)
{
const unsigned long be_to_le = BITS_PER_LONG - 1;
bit_spin_unlock(bit ^ be_to_le, iv->bitlock);
}
static inline void airq_iv_set_data(struct airq_iv *iv, unsigned long bit,
unsigned int data)
{
iv->data[bit] = data;
}
static inline unsigned int airq_iv_get_data(struct airq_iv *iv,
unsigned long bit)
{
return iv->data[bit];
}
static inline void airq_iv_set_ptr(struct airq_iv *iv, unsigned long bit,
unsigned long ptr)
{
iv->ptr[bit] = ptr;
}
static inline unsigned long airq_iv_get_ptr(struct airq_iv *iv,
unsigned long bit)
{
return iv->ptr[bit];
}
#endif /* _ASM_S390_AIRQ_H */

View File

@ -93,3 +93,156 @@ void do_adapter_IO(u8 isc)
airq->handler(airq);
rcu_read_unlock();
}
/**
* 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)
{
const unsigned long be_to_le = BITS_PER_LONG - 1;
unsigned long bit;
if (!iv->avail)
return -1UL;
spin_lock(&iv->lock);
bit = find_first_bit_left(iv->avail, iv->bits);
if (bit < iv->bits) {
clear_bit(bit ^ be_to_le, 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)
{
const unsigned long be_to_le = BITS_PER_LONG - 1;
if (!iv->avail)
return;
spin_lock(&iv->lock);
/* Clear (possibly left over) interrupt bit */
clear_bit(bit ^ be_to_le, iv->vector);
/* Make the bit position available again */
set_bit(bit ^ be_to_le, iv->avail);
if (bit == iv->end - 1) {
/* Find new end of bit-field */
while (--iv->end > 0)
if (!test_bit((iv->end - 1) ^ be_to_le, 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)
{
const unsigned long be_to_le = BITS_PER_LONG - 1;
unsigned long bit;
/* Find non-zero bit starting from 'ivs->next'. */
bit = find_next_bit_left(iv->vector, end, start);
if (bit >= end)
return -1UL;
/* Clear interrupt bit (find left uses big-endian bit numbers) */
clear_bit(bit ^ be_to_le, iv->vector);
return bit;
}
EXPORT_SYMBOL(airq_iv_scan);