From: Martin Schwidefsky Date: Tue, 25 Jun 2013 12:17:57 +0000 (+0200) Subject: s390/airq: introduce adapter interrupt vector helper X-Git-Tag: next-20130731~91^2~8 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ba98b385081c001dae463d12dd783e8c93b59bd7;p=karo-tx-linux.git 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 Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/include/asm/airq.h b/arch/s390/include/asm/airq.h index 4066cee0c2d2..4057acba67c4 100644 --- a/arch/s390/include/asm/airq.h +++ b/arch/s390/include/asm/airq.h @@ -23,4 +23,41 @@ 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 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_DATA 2 /* 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_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]; +} + #endif /* _ASM_S390_AIRQ_H */ diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c index 91edbd7ee806..c7ffb790a24d 100644 --- a/drivers/s390/cio/airq.c +++ b/drivers/s390/cio/airq.c @@ -93,3 +93,143 @@ 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_iv; + if (flags & AIRQ_IV_ALLOC) { + iv->avail = kmalloc(size, GFP_KERNEL); + if (!iv->avail) + goto out_vector; + memset(iv->avail, 0xff, size); + iv->end = 0; + } else + iv->end = bits; + if (flags & AIRQ_IV_DATA) { + size = bits * sizeof(unsigned int); + iv->data = kzalloc(size, GFP_KERNEL); + if (!iv->data) + goto out_alloc; + } + spin_lock_init(&iv->lock); + return iv; + +out_alloc: + kfree(iv->avail); +out_vector: + kfree(iv->vector); +out_iv: + 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->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);