| /* |
| * linux/drivers/s390/cio/thinint_qdio.c |
| * |
| * thin interrupt support for qdio |
| * |
| * Copyright 2000-2008 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 <asm/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" |
| #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); |
| |
| /* 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; |
| |
| for_each_input_queue(irq_ptr, q, i) { |
| list_add_rcu(&q->entry, &tiq_list); |
| synchronize_rcu(); |
| } |
| 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; |
| list_del_rcu(&q->entry); |
| synchronize_rcu(); |
| } |
| } |
| |
| static inline int tiqdio_inbound_q_done(struct qdio_q *q) |
| { |
| unsigned char state; |
| |
| if (!atomic_read(&q->nr_buf_used)) |
| return 1; |
| |
| qdio_siga_sync_q(q); |
| get_buf_state(q, q->first_to_check, &state); |
| |
| 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; |
| char dbf_text[15]; |
| void *ptr; |
| 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) { |
| sprintf(dbf_text, "sidR%4x", scssc_area->response.code); |
| QDIO_DBF_TEXT1(0, trace, dbf_text); |
| QDIO_DBF_TEXT1(0, setup, dbf_text); |
| ptr = &scssc_area->response; |
| QDIO_DBF_HEX2(1, setup, &ptr, QDIO_DBF_SETUP_LEN); |
| return rc; |
| } |
| |
| QDIO_DBF_TEXT2(0, setup, "setscind"); |
| QDIO_DBF_HEX2(0, setup, &scssc_area->summary_indicator_addr, |
| sizeof(unsigned long)); |
| QDIO_DBF_HEX2(0, setup, &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) |
| { |
| char dbf_text[20]; |
| |
| isc_register(QDIO_AIRQ_ISC); |
| tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler, |
| NULL, QDIO_AIRQ_ISC); |
| if (IS_ERR(tiqdio_alsi)) { |
| sprintf(dbf_text, "regthn%lx", PTR_ERR(tiqdio_alsi)); |
| QDIO_DBF_TEXT0(0, setup, dbf_text); |
| 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(); |
| QDIO_DBF_HEX1(0, setup, &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); |
| } |
| } |