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author | Jan Glauber <jang@linux.vnet.ibm.com> | 2008-07-17 17:16:48 +0200 |
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committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2008-07-17 17:22:10 +0200 |
commit | 779e6e1c724d30e0fd1baca78b852e41e3a23c1d (patch) | |
tree | b7fc4f0f01b66c3c65226cc627edd501e00ab44f /drivers/s390/cio/qdio_thinint.c | |
parent | dae39843f478d181da5b5e1c2c703dfcaaf838c1 (diff) | |
download | linux-779e6e1c724d30e0fd1baca78b852e41e3a23c1d.tar.bz2 |
[S390] qdio: new qdio driver.
List of major changes:
- split qdio driver into several files
- seperation of thin interrupt code
- improved handling for multiple thin interrupt devices
- inbound and outbound processing now always runs in tasklet context
- significant less tasklet schedules per interrupt needed
- merged qebsm with non-qebsm handling
- cleanup qdio interface and added kerneldoc
- coding style
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Utz Bacher <utz.bacher@de.ibm.com>
Reviewed-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio/qdio_thinint.c')
-rw-r--r-- | drivers/s390/cio/qdio_thinint.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c new file mode 100644 index 000000000000..9291a771d812 --- /dev/null +++ b/drivers/s390/cio/qdio_thinint.c @@ -0,0 +1,380 @@ +/* + * 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_each_input_queue(irq_ptr, q, i) { + 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); + } +} |