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s390/airq: add support for irq ranges

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Add airq_iv_alloc and airq_iv_free to allocate and free consecutive
ranges of irqs from the interrupt vector.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2014-02-13 13:02:32 +01:00
parent ec66ad66a0
commit fe7c30a420
2 changed files with 53 additions and 27 deletions
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14
arch/s390/include/asm/airq.h
View File

@ -44,11 +44,21 @@ struct airq_iv {
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_alloc(struct airq_iv *iv, unsigned long num);
void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num);
unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
unsigned long end);
static inline unsigned long airq_iv_alloc_bit(struct airq_iv *iv)
{
return airq_iv_alloc(iv, 1);
}
static inline void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit)
{
airq_iv_free(iv, bit, 1);
}
static inline unsigned long airq_iv_end(struct airq_iv *iv)
{
return iv->end;

66
drivers/s390/cio/airq.c
View File

@ -186,55 +186,71 @@ void airq_iv_release(struct airq_iv *iv)
EXPORT_SYMBOL(airq_iv_release);
/**
* airq_iv_alloc_bit - allocate an irq bit from an interrupt vector
* airq_iv_alloc - allocate irq bits from an interrupt vector
* @iv: pointer to an interrupt vector structure
* @num: number of consecutive irq bits to allocate
*
* 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
* Returns the bit number of the first irq in the allocated block of irqs,
* 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 airq_iv_alloc(struct airq_iv *iv, unsigned long num)
{
unsigned long bit;
unsigned long bit, i;
if (!iv->avail)
if (!iv->avail || num == 0)
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
while (bit + num <= iv->bits) {
for (i = 1; i < num; i++)
if (!test_bit_inv(bit + i, iv->avail))
break;
if (i >= num) {
/* Found a suitable block of irqs */
for (i = 0; i < num; i++)
clear_bit_inv(bit + i, iv->avail);
if (bit + num >= iv->end)
iv->end = bit + num + 1;
break;
}
bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1);
}
if (bit + num > iv->bits)
bit = -1UL;
spin_unlock(&iv->lock);
return bit;
}
EXPORT_SYMBOL(airq_iv_alloc_bit);
EXPORT_SYMBOL(airq_iv_alloc);
/**
* airq_iv_free_bit - free an irq bit of an interrupt vector
* airq_iv_free - free irq bits of an interrupt vector
* @iv: pointer to interrupt vector structure
* @bit: number of the irq bit to free
* @bit: number of the first irq bit to free
* @num: number of consecutive irq bits to free
*/
void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit)
void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
{
if (!iv->avail)
unsigned long i;
if (!iv->avail || num == 0)
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) {
for (i = 0; i < num; i++) {
/* Clear (possibly left over) interrupt bit */
clear_bit_inv(bit + i, iv->vector);
/* Make the bit positions available again */
set_bit_inv(bit + i, iv->avail);
}
if (bit + num >= iv->end) {
/* Find new end of bit-field */
while (--iv->end > 0)
if (!test_bit_inv(iv->end - 1, iv->avail))
break;
while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
iv->end--;
}
spin_unlock(&iv->lock);
}
EXPORT_SYMBOL(airq_iv_free_bit);
EXPORT_SYMBOL(airq_iv_free);
/**
* airq_iv_scan - scan interrupt vector for non-zero bits