diff options
Diffstat (limited to 'drivers/s390')
-rw-r--r-- | drivers/s390/cio/airq.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c index 91edbd7ee806..6ead6d076445 100644 --- a/drivers/s390/cio/airq.c +++ b/drivers/s390/cio/airq.c @@ -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); |