linux/drivers/s390/cio/qdio_thinint.c
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

323 lines
7.4 KiB
C

/*
* Copyright IBM Corp. 2000, 2009
* 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);
}
}