/* * linux/drivers/s390/cio/thinint_qdio.c * * thin interrupt support for qdio * * Copyright 2000-2008 IBM Corp. * Author(s): Utz Bacher * Cornelia Huck * Jan Glauber */ #include #include #include #include #include #include #include "cio.h" #include "ioasm.h" #include "qdio.h" #include "qdio_debug.h" #include "qdio_perf.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 /* list of thin interrupt input queues */ static LIST_HEAD(tiq_list); DEFINE_MUTEX(tiq_list_lock); /* adapter local summary indicator */ static unsigned char *tiqdio_alsi; /* 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 */ }; static struct indicator_t *q_indicators; static void tiqdio_tasklet_fn(unsigned long data); static DECLARE_TASKLET(tiqdio_tasklet, tiqdio_tasklet_fn, 0); static int css_qdio_omit_svs; static inline unsigned long do_clear_global_summary(void) { register unsigned long __fn asm("1") = 3; register unsigned long __tmp asm("2"); register unsigned long __time asm("3"); asm volatile( " .insn rre,0xb2650000,2,0" : "+d" (__fn), "=d" (__tmp), "=d" (__time)); return __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) { struct qdio_q *q; int i; /* No TDD facility? If we must use SIGA-s we can also omit SVS. */ if (!css_qdio_omit_svs && irq_ptr->siga_flag.sync) css_qdio_omit_svs = 1; mutex_lock(&tiq_list_lock); for_each_input_queue(irq_ptr, q, i) list_add_rcu(&q->entry, &tiq_list); mutex_unlock(&tiq_list_lock); xchg(irq_ptr->dsci, 1); tasklet_schedule(&tiqdio_tasklet); } /* * we cannot stop the tiqdio tasklet here since it is for all * thinint qdio devices and it must run as long as there is a * thinint device left */ void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr) { struct qdio_q *q; int i; for (i = 0; i < irq_ptr->nr_input_qs; i++) { q = irq_ptr->input_qs[i]; /* if establish triggered an error */ if (!q || !q->entry.prev || !q->entry.next) continue; mutex_lock(&tiq_list_lock); list_del_rcu(&q->entry); mutex_unlock(&tiq_list_lock); synchronize_rcu(); } } static inline int tiqdio_inbound_q_done(struct qdio_q *q) { unsigned char state = 0; if (!atomic_read(&q->nr_buf_used)) return 1; qdio_siga_sync_q(q); get_buf_state(q, q->first_to_check, &state, 0); if (state == SLSB_P_INPUT_PRIMED) /* more work coming */ return 0; return 1; } static inline int shared_ind(struct qdio_irq *irq_ptr) { return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind; } static void __tiqdio_inbound_processing(struct qdio_q *q) { qdio_perf_stat_inc(&perf_stats.thinint_inbound); qdio_sync_after_thinint(q); /* * Maybe we have work on our outbound queues... at least * we have to check the PCI capable queues. */ qdio_check_outbound_after_thinint(q); again: if (!qdio_inbound_q_moved(q)) return; qdio_kick_inbound_handler(q); if (!tiqdio_inbound_q_done(q)) { qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop); goto again; } qdio_stop_polling(q); /* * We need to check again to not lose initiative after * resetting the ACK state. */ if (!tiqdio_inbound_q_done(q)) { qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop2); goto again; } } void tiqdio_inbound_processing(unsigned long data) { struct qdio_q *q = (struct qdio_q *)data; __tiqdio_inbound_processing(q); } /* check for work on all inbound thinint queues */ static void tiqdio_tasklet_fn(unsigned long data) { struct qdio_q *q; qdio_perf_stat_inc(&perf_stats.tasklet_thinint); again: /* protect tiq_list entries, only changed in activate or shutdown */ rcu_read_lock(); list_for_each_entry_rcu(q, &tiq_list, entry) /* only process queues from changed sets */ if (*q->irq_ptr->dsci) { /* only clear it if the indicator is non-shared */ if (!shared_ind(q->irq_ptr)) xchg(q->irq_ptr->dsci, 0); /* * don't call inbound processing directly since * that could starve other thinint queues */ tasklet_schedule(&q->tasklet); } rcu_read_unlock(); /* * if we used the shared indicator clear it now after all queues * were processed */ if (atomic_read(&q_indicators[TIQDIO_SHARED_IND].count)) { xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0); /* prevent racing */ if (*tiqdio_alsi) xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 1); } /* check for more work */ if (*tiqdio_alsi) { xchg(tiqdio_alsi, 0); qdio_perf_stat_inc(&perf_stats.tasklet_thinint_loop); goto again; } } /** * tiqdio_thinint_handler - thin interrupt handler for qdio * @ind: pointer to adapter local summary indicator * @drv_data: NULL */ static void tiqdio_thinint_handler(void *ind, void *drv_data) { qdio_perf_stat_inc(&perf_stats.thin_int); /* * SVS only when needed: issue SVS to benefit from iqdio interrupt * avoidance (SVS clears adapter interrupt suppression overwrite) */ if (!css_qdio_omit_svs) do_clear_global_summary(); /* * reset local summary indicator (tiqdio_alsi) to stop adapter * interrupts for now, the tasklet will clean all dsci's */ xchg((u8 *)ind, 0); tasklet_hi_schedule(&tiqdio_tasklet); } 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; scssc_area->kc = PAGE_DEFAULT_KEY; 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; /* Check for aif time delay disablement. If installed, * omit SVS even under LPAR */ if (css_general_characteristics.aif_tdd) css_qdio_omit_svs = 1; 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 */ put_indicator(irq_ptr->dsci); set_subchannel_ind(irq_ptr, 1); } void __exit tiqdio_unregister_thinints(void) { tasklet_disable(&tiqdio_tasklet); if (tiqdio_alsi) { s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC); isc_unregister(QDIO_AIRQ_ISC); } }