Commit fe7c30a4 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/airq: add support for irq ranges 



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

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent ec66ad66

arch/s390/include/asm/airq.h

+12 −2
Original line number Diff line number Diff line
@@ -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;

drivers/s390/cio/airq.c

+41 −25
Original line number Diff line number Diff line
@@ -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);

	for (i = 0; i < num; i++) {

		/* 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) {

		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