/* * linux/drivers/s390/cio/thinint_qdio.c * * Copyright 2000,2009 IBM Corp. * Author(s): Utz Bacher <utz.bacher@de.ibm.com> * Cornelia Huck <cornelia.huck@de.ibm.com> * Jan Glauber <jang@linux.vnet.ibm.com> */ #include <linux/io.h> #include <linux/slab.h> #include <linux/kernel_stat.h> #include <linux/atomic.h> #include <asm/debug.h> #include <asm/qdio.h> #include <asm/airq.h> #include <asm/isc.h> #include "cio.h" #include "ioasm.h" #include "qdio.h" #include "qdio_debug.h" /* * Restriction: only 63 iqdio subchannels would have its own indicator, * after that, subsequent subchannels share one indicator */ #define TIQDIO_NR_NONSHARED_IND 63 #define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1) #define TIQDIO_SHARED_IND 63 /* device state change indicators */ struct indicator_t { u32 ind; /* u32 because of compare-and-swap performance */ atomic_t count; /* use count, 0 or 1 for non-shared indicators */ }; /* list of thin interrupt input queues */ static LIST_HEAD(tiq_list); static DEFINE_MUTEX(tiq_list_lock); /* adapter local summary indicator */ static u8 *tiqdio_alsi; static struct indicator_t *q_indicators; u64 last_ai_time; /* returns addr for the device state change indicator */ static u32 *get_indicator(void) { int i; for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++) if (!atomic_read(&q_indicators[i].count)) { atomic_set(&q_indicators[i].count, 1); return &q_indicators[i].ind; } /* use the shared indicator */ atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count); return &q_indicators[TIQDIO_SHARED_IND].ind; } static void put_indicator(u32 *addr) { int i; if (!addr) return; i = ((unsigned long)addr - (unsigned long)q_indicators) / sizeof(struct indicator_t); atomic_dec(&q_indicators[i].count); } void tiqdio_add_input_queues(struct qdio_irq *irq_ptr) { mutex_lock(&tiq_list_lock); BUG_ON(irq_ptr->nr_input_qs < 1); list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list); mutex_unlock(&tiq_list_lock); xchg(irq_ptr->dsci, 1 << 7); } void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr) { struct qdio_q *q; BUG_ON(irq_ptr->nr_input_qs < 1); q = irq_ptr->input_qs[0]; /* if establish triggered an error */ if (!q || !q->entry.prev || !q->entry.next) return; mutex_lock(&tiq_list_lock); list_del_rcu(&q->entry); mutex_unlock(&tiq_list_lock); synchronize_rcu(); } static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr) { return irq_ptr->nr_input_qs > 1; } static inline int references_shared_dsci(struct qdio_irq *irq_ptr) { return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind; } static inline int shared_ind(struct qdio_irq *irq_ptr) { return references_shared_dsci(irq_ptr) || has_multiple_inq_on_dsci(irq_ptr); } void clear_nonshared_ind(struct qdio_irq *irq_ptr) { if (!is_thinint_irq(irq_ptr)) return; if (shared_ind(irq_ptr)) return; xchg(irq_ptr->dsci, 0); } int test_nonshared_ind(struct qdio_irq *irq_ptr) { if (!is_thinint_irq(irq_ptr)) return 0; if (shared_ind(irq_ptr)) return 0; if (*irq_ptr->dsci) return 1; else return 0; } static inline u32 clear_shared_ind(void) { if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count)) return 0; return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0); } static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq) { struct qdio_q *q; int i; for_each_input_queue(irq, q, i) { if (!references_shared_dsci(irq) && has_multiple_inq_on_dsci(irq)) xchg(q->irq_ptr->dsci, 0); if (q->u.in.queue_start_poll) { /* skip if polling is enabled or already in work */ if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED, &q->u.in.queue_irq_state)) { qperf_inc(q, int_discarded); continue; } /* avoid dsci clear here, done after processing */ q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr, q->irq_ptr->int_parm); } else { if (!shared_ind(q->irq_ptr)) xchg(q->irq_ptr->dsci, 0); /* * Call inbound processing but not directly * since that could starve other thinint queues. */ tasklet_schedule(&q->tasklet); } } } /** * tiqdio_thinint_handler - thin interrupt handler for qdio * @alsi: pointer to adapter local summary indicator * @data: NULL */ static void tiqdio_thinint_handler(void *alsi, void *data) { u32 si_used = clear_shared_ind(); struct qdio_q *q; last_ai_time = S390_lowcore.int_clock; kstat_cpu(smp_processor_id()).irqs[IOINT_QAI]++; /* protect tiq_list entries, only changed in activate or shutdown */ rcu_read_lock(); /* check for work on all inbound thinint queues */ list_for_each_entry_rcu(q, &tiq_list, entry) { struct qdio_irq *irq; /* only process queues from changed sets */ irq = q->irq_ptr; if (unlikely(references_shared_dsci(irq))) { if (!si_used) continue; } else if (!*irq->dsci) continue; tiqdio_call_inq_handlers(irq); qperf_inc(q, adapter_int); } rcu_read_unlock(); } static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset) { struct scssc_area *scssc_area; int rc; scssc_area = (struct scssc_area *)irq_ptr->chsc_page; memset(scssc_area, 0, PAGE_SIZE); if (reset) { scssc_area->summary_indicator_addr = 0; scssc_area->subchannel_indicator_addr = 0; } else { scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi); scssc_area->subchannel_indicator_addr = virt_to_phys(irq_ptr->dsci); } scssc_area->request = (struct chsc_header) { .length = 0x0fe0, .code = 0x0021, }; scssc_area->operation_code = 0; scssc_area->ks = PAGE_DEFAULT_KEY >> 4; scssc_area->kc = PAGE_DEFAULT_KEY >> 4; scssc_area->isc = QDIO_AIRQ_ISC; scssc_area->schid = irq_ptr->schid; /* enable the time delay disablement facility */ if (css_general_characteristics.aif_tdd) scssc_area->word_with_d_bit = 0x10000000; rc = chsc(scssc_area); if (rc) return -EIO; rc = chsc_error_from_response(scssc_area->response.code); if (rc) { DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no, scssc_area->response.code); DBF_ERROR_HEX(&scssc_area->response, sizeof(void *)); return rc; } DBF_EVENT("setscind"); DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long)); DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long)); return 0; } /* allocate non-shared indicators and shared indicator */ int __init tiqdio_allocate_memory(void) { q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS, GFP_KERNEL); if (!q_indicators) return -ENOMEM; return 0; } void tiqdio_free_memory(void) { kfree(q_indicators); } int __init tiqdio_register_thinints(void) { isc_register(QDIO_AIRQ_ISC); tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler, NULL, QDIO_AIRQ_ISC); if (IS_ERR(tiqdio_alsi)) { DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi)); tiqdio_alsi = NULL; isc_unregister(QDIO_AIRQ_ISC); return -ENOMEM; } return 0; } int qdio_establish_thinint(struct qdio_irq *irq_ptr) { if (!is_thinint_irq(irq_ptr)) return 0; return set_subchannel_ind(irq_ptr, 0); } void qdio_setup_thinint(struct qdio_irq *irq_ptr) { if (!is_thinint_irq(irq_ptr)) return; irq_ptr->dsci = get_indicator(); DBF_HEX(&irq_ptr->dsci, sizeof(void *)); } void qdio_shutdown_thinint(struct qdio_irq *irq_ptr) { if (!is_thinint_irq(irq_ptr)) return; /* reset adapter interrupt indicators */ set_subchannel_ind(irq_ptr, 1); put_indicator(irq_ptr->dsci); } void __exit tiqdio_unregister_thinints(void) { WARN_ON(!list_empty(&tiq_list)); if (tiqdio_alsi) { s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC); isc_unregister(QDIO_AIRQ_ISC); } }