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