diff options
Diffstat (limited to 'drivers/s390/cio/airq.c')
| -rw-r--r-- | drivers/s390/cio/airq.c | 171 |
1 files changed, 115 insertions, 56 deletions
diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c index 5287631fbfc8..b7a07a866291 100644 --- a/drivers/s390/cio/airq.c +++ b/drivers/s390/cio/airq.c @@ -1,12 +1,12 @@ /* * drivers/s390/cio/airq.c - * S/390 common I/O routines -- support for adapter interruptions + * Support for adapter interruptions * - * Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH, - * IBM Corporation - * Author(s): Ingo Adlung (adlung@de.ibm.com) - * Cornelia Huck (cornelia.huck@de.ibm.com) - * Arnd Bergmann (arndb@de.ibm.com) + * Copyright IBM Corp. 1999,2007 + * Author(s): Ingo Adlung <adlung@de.ibm.com> + * Cornelia Huck <cornelia.huck@de.ibm.com> + * Arnd Bergmann <arndb@de.ibm.com> + * Peter Oberparleiter <peter.oberparleiter@de.ibm.com> */ #include <linux/init.h> @@ -14,72 +14,131 @@ #include <linux/slab.h> #include <linux/rcupdate.h> +#include <asm/airq.h> + +#include "cio.h" #include "cio_debug.h" -#include "airq.h" -static adapter_int_handler_t adapter_handler; +#define NR_AIRQS 32 +#define NR_AIRQS_PER_WORD sizeof(unsigned long) +#define NR_AIRQ_WORDS (NR_AIRQS / NR_AIRQS_PER_WORD) -/* - * register for adapter interrupts - * - * With HiperSockets the zSeries architecture provides for - * means of adapter interrups, pseudo I/O interrupts that are - * not tied to an I/O subchannel, but to an adapter. However, - * it doesn't disclose the info how to enable/disable them, but - * to recognize them only. Perhaps we should consider them - * being shared interrupts, and thus build a linked list - * of adapter handlers ... to be evaluated ... - */ -int -s390_register_adapter_interrupt (adapter_int_handler_t handler) -{ - int ret; - char dbf_txt[15]; +union indicator_t { + unsigned long word[NR_AIRQ_WORDS]; + unsigned char byte[NR_AIRQS]; +} __attribute__((packed)); - CIO_TRACE_EVENT (4, "rgaint"); +struct airq_t { + adapter_int_handler_t handler; + void *drv_data; +}; - if (handler == NULL) - ret = -EINVAL; - else - ret = (cmpxchg(&adapter_handler, NULL, handler) ? -EBUSY : 0); - if (!ret) - synchronize_sched(); /* Allow interrupts to complete. */ +static union indicator_t indicators; +static struct airq_t *airqs[NR_AIRQS]; - sprintf (dbf_txt, "ret:%d", ret); - CIO_TRACE_EVENT (4, dbf_txt); +static int register_airq(struct airq_t *airq) +{ + int i; - return ret; + for (i = 0; i < NR_AIRQS; i++) + if (!cmpxchg(&airqs[i], NULL, airq)) + return i; + return -ENOMEM; } -int -s390_unregister_adapter_interrupt (adapter_int_handler_t handler) +/** + * 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 + * + * Returns: + * Pointer to the indicator to be used on success + * ERR_PTR() if registration failed + */ +void *s390_register_adapter_interrupt(adapter_int_handler_t handler, + void *drv_data) { + struct airq_t *airq; + char dbf_txt[16]; int ret; - char dbf_txt[15]; - CIO_TRACE_EVENT (4, "urgaint"); - - if (handler == NULL) - ret = -EINVAL; - else { - adapter_handler = NULL; - synchronize_sched(); /* Allow interrupts to complete. */ - ret = 0; + airq = kmalloc(sizeof(struct airq_t), GFP_KERNEL); + if (!airq) { + ret = -ENOMEM; + goto out; } - sprintf (dbf_txt, "ret:%d", ret); - CIO_TRACE_EVENT (4, dbf_txt); - - return ret; + airq->handler = handler; + airq->drv_data = drv_data; + ret = register_airq(airq); + if (ret < 0) + kfree(airq); +out: + snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%d", ret); + CIO_TRACE_EVENT(4, dbf_txt); + if (ret < 0) + return ERR_PTR(ret); + else + return &indicators.byte[ret]; } +EXPORT_SYMBOL(s390_register_adapter_interrupt); -void -do_adapter_IO (void) +/** + * s390_unregister_adapter_interrupt - unregister adapter interrupt handler + * @ind: indicator for which the handler is to be unregistered + */ +void s390_unregister_adapter_interrupt(void *ind) { - CIO_TRACE_EVENT (6, "doaio"); + struct airq_t *airq; + char dbf_txt[16]; + int i; - if (adapter_handler) - (*adapter_handler) (); + i = (int) ((addr_t) ind) - ((addr_t) &indicators.byte[0]); + snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%d", i); + CIO_TRACE_EVENT(4, dbf_txt); + indicators.byte[i] = 0; + airq = xchg(&airqs[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); } +EXPORT_SYMBOL(s390_unregister_adapter_interrupt); + +#define INDICATOR_MASK (0xffUL << ((NR_AIRQS_PER_WORD - 1) * 8)) -EXPORT_SYMBOL (s390_register_adapter_interrupt); -EXPORT_SYMBOL (s390_unregister_adapter_interrupt); +void do_adapter_IO(void) +{ + 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.word[w]; + i = w * NR_AIRQS_PER_WORD; + /* + * Check bytes within word for active indicators. + */ + while (word) { + if (word & INDICATOR_MASK) { + airq = airqs[i]; + if (likely(airq)) + airq->handler(&indicators.byte[i], + airq->drv_data); + else + /* + * Reset ill-behaved indicator. + */ + indicators.byte[i] = 0; + } + word <<= 8; + i++; + } + } +} |