From 84ec96a6150477b9509664557bc6ad4eaa21f72a Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 13 Feb 2014 13:02:32 +0100 Subject: [PATCH] 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: Martin Schwidefsky Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/airq.h | 14 ++++++-- drivers/s390/cio/airq.c | 66 ++++++++++++++++++++++-------------- 2 files changed, 53 insertions(+), 27 deletions(-) diff --git a/arch/s390/include/asm/airq.h b/arch/s390/include/asm/airq.h index 4bbb5957ed1b..bd93ff6661b8 100644 --- a/arch/s390/include/asm/airq.h +++ b/arch/s390/include/asm/airq.h @@ -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; diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c index f055df0b167f..445564c790f6 100644 --- a/drivers/s390/cio/airq.c +++ b/drivers/s390/cio/airq.c @@ -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 -- 2.20.1