From f4eae94f71372ea5ec1ba17a85f3aebedc516ca8 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 24 Jun 2013 10:30:41 +0200 Subject: s390/airq: simplify adapter interrupt code There are three users of adapter interrupts: AP, QDIO and PCI. Each registers a single adapter interrupt with independent ISCs. Define a "struct airq" with the interrupt handler, a pointer and a mask for the local summary indicator and the ISC for the adapter interrupt source. Convert the indicator array with its fixed number of adapter interrupt sources per ISE to an array of hlists. This removes the limitation to 32 adapter interrupts per ISC and allows for arbitrary memory locations for the local summary indicator. Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/airq.c | 167 ++++++++++++++++-------------------------------- 1 file changed, 56 insertions(+), 111 deletions(-) (limited to 'drivers/s390/cio/airq.c') diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c index bc10220f684..91edbd7ee80 100644 --- a/drivers/s390/cio/airq.c +++ b/drivers/s390/cio/airq.c @@ -9,142 +9,87 @@ */ #include +#include +#include #include +#include +#include #include -#include #include #include #include "cio.h" #include "cio_debug.h" +#include "ioasm.h" -#define NR_AIRQS 32 -#define NR_AIRQS_PER_WORD sizeof(unsigned long) -#define NR_AIRQ_WORDS (NR_AIRQS / NR_AIRQS_PER_WORD) - -union indicator_t { - unsigned long word[NR_AIRQ_WORDS]; - unsigned char byte[NR_AIRQS]; -} __attribute__((packed)); - -struct airq_t { - adapter_int_handler_t handler; - void *drv_data; -}; - -static union indicator_t indicators[MAX_ISC+1]; -static struct airq_t *airqs[MAX_ISC+1][NR_AIRQS]; - -static int register_airq(struct airq_t *airq, u8 isc) -{ - int i; - - for (i = 0; i < NR_AIRQS; i++) - if (!cmpxchg(&airqs[isc][i], NULL, airq)) - return i; - return -ENOMEM; -} +static DEFINE_SPINLOCK(airq_lists_lock); +static struct hlist_head airq_lists[MAX_ISC+1]; /** - * s390_register_adapter_interrupt() - register adapter interrupt handler - * @handler: adapter handler to be registered - * @drv_data: driver data passed with each call to the handler - * @isc: isc for which the handler should be called + * register_adapter_interrupt() - register adapter interrupt handler + * @airq: pointer to adapter interrupt descriptor * - * Returns: - * Pointer to the indicator to be used on success - * ERR_PTR() if registration failed + * Returns 0 on success, or -EINVAL. */ -void *s390_register_adapter_interrupt(adapter_int_handler_t handler, - void *drv_data, u8 isc) +int register_adapter_interrupt(struct airq_struct *airq) { - struct airq_t *airq; - char dbf_txt[16]; - int ret; - - if (isc > MAX_ISC) - return ERR_PTR(-EINVAL); - airq = kmalloc(sizeof(struct airq_t), GFP_KERNEL); - if (!airq) { - ret = -ENOMEM; - goto out; + char dbf_txt[32]; + + if (!airq->handler || airq->isc > MAX_ISC) + return -EINVAL; + if (!airq->lsi_ptr) { + airq->lsi_ptr = kzalloc(1, GFP_KERNEL); + if (!airq->lsi_ptr) + return -ENOMEM; + airq->flags |= AIRQ_PTR_ALLOCATED; } - airq->handler = handler; - airq->drv_data = drv_data; - - ret = register_airq(airq, isc); -out: - snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%d", ret); + if (!airq->lsi_mask) + airq->lsi_mask = 0xff; + snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq); CIO_TRACE_EVENT(4, dbf_txt); - if (ret < 0) { - kfree(airq); - return ERR_PTR(ret); - } else - return &indicators[isc].byte[ret]; + isc_register(airq->isc); + spin_lock(&airq_lists_lock); + hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]); + spin_unlock(&airq_lists_lock); + return 0; } -EXPORT_SYMBOL(s390_register_adapter_interrupt); +EXPORT_SYMBOL(register_adapter_interrupt); /** - * s390_unregister_adapter_interrupt - unregister adapter interrupt handler - * @ind: indicator for which the handler is to be unregistered - * @isc: interruption subclass + * unregister_adapter_interrupt - unregister adapter interrupt handler + * @airq: pointer to adapter interrupt descriptor */ -void s390_unregister_adapter_interrupt(void *ind, u8 isc) +void unregister_adapter_interrupt(struct airq_struct *airq) { - struct airq_t *airq; - char dbf_txt[16]; - int i; + char dbf_txt[32]; - i = (int) ((addr_t) ind) - ((addr_t) &indicators[isc].byte[0]); - snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%d", i); + if (hlist_unhashed(&airq->list)) + return; + snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq); CIO_TRACE_EVENT(4, dbf_txt); - indicators[isc].byte[i] = 0; - airq = xchg(&airqs[isc][i], NULL); - /* - * Allow interrupts to complete. This will ensure that the airq handle - * is no longer referenced by any interrupt handler. - */ - synchronize_sched(); - kfree(airq); + spin_lock(&airq_lists_lock); + hlist_del_rcu(&airq->list); + spin_unlock(&airq_lists_lock); + synchronize_rcu(); + isc_unregister(airq->isc); + if (airq->flags & AIRQ_PTR_ALLOCATED) { + kfree(airq->lsi_ptr); + airq->lsi_ptr = NULL; + airq->flags &= ~AIRQ_PTR_ALLOCATED; + } } -EXPORT_SYMBOL(s390_unregister_adapter_interrupt); - -#define INDICATOR_MASK (0xffUL << ((NR_AIRQS_PER_WORD - 1) * 8)) +EXPORT_SYMBOL(unregister_adapter_interrupt); void do_adapter_IO(u8 isc) { - int w; - int i; - unsigned long word; - struct airq_t *airq; - - /* - * Access indicator array in word-sized chunks to minimize storage - * fetch operations. - */ - for (w = 0; w < NR_AIRQ_WORDS; w++) { - word = indicators[isc].word[w]; - i = w * NR_AIRQS_PER_WORD; - /* - * Check bytes within word for active indicators. - */ - while (word) { - if (word & INDICATOR_MASK) { - airq = airqs[isc][i]; - /* Make sure gcc reads from airqs only once. */ - barrier(); - if (likely(airq)) - airq->handler(&indicators[isc].byte[i], - airq->drv_data); - else - /* - * Reset ill-behaved indicator. - */ - indicators[isc].byte[i] = 0; - } - word <<= 8; - i++; - } - } + struct airq_struct *airq; + struct hlist_head *head; + + head = &airq_lists[isc]; + rcu_read_lock(); + hlist_for_each_entry_rcu(airq, head, list) + if ((*airq->lsi_ptr & airq->lsi_mask) != 0) + airq->handler(airq); + rcu_read_unlock(); } -- cgit v1.2.3-70-g09d2