[net-next-2.6.git] / drivers / s390 / cio / qdio_thinint.c

/*
 * linux/drivers/s390/cio/thinint_qdio.c
 *
 * Copyright 2000,2009 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 <linux/slab.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"

/*
 * 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)

/* list of thin interrupt input queues */
static LIST_HEAD(tiq_list);
DEFINE_MUTEX(tiq_list_lock);

/* adapter local summary indicator */
static u8 *tiqdio_alsi;

struct indicator_t *q_indicators;

static int css_qdio_omit_svs;

static u64 last_ai_time;

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 << 7);
}

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 shared_ind_used(void)
{
	return atomic_read(&q_indicators[TIQDIO_SHARED_IND].count);
}

/**
 * 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)
{
	struct qdio_q *q;

	last_ai_time = S390_lowcore.int_clock;

	/*
	 * 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 */
	if (shared_ind_used())
		xchg(tiqdio_alsi, 0);

	/* 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) {

		/* only process queues from changed sets */
		if (!*q->irq_ptr->dsci)
			continue;

		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 {
			/* only clear it if the indicator is non-shared */
			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);
		}
		qperf_inc(q, adapter_int);
	}
	rcu_read_unlock();

	/*
	 * If the shared indicator was used clear it now after all queues
	 * were processed.
	 */
	if (shared_ind_used()) {
		xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);

		/* prevent racing */
		if (*tiqdio_alsi)
			xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 1 << 7);
	}
}

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;

	/* 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)
{
	WARN_ON(!list_empty(&tiq_list));

	if (tiqdio_alsi) {
		s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
		isc_unregister(QDIO_AIRQ_ISC);
	}
}
Commit	Line	Data
779e6e1c JG	1	/*
	2	* linux/drivers/s390/cio/thinint_qdio.c
	3	*
6486cda6	4	* Copyright 2000,2009 IBM Corp.
779e6e1c JG	5	* Author(s): Utz Bacher <utz.bacher@de.ibm.com>
	6	* Cornelia Huck <cornelia.huck@de.ibm.com>
	7	* Jan Glauber <jang@linux.vnet.ibm.com>
	8	*/
	9	#include <linux/io.h>
5a0e3ad6	10	#include <linux/slab.h>
779e6e1c JG	11	#include <asm/atomic.h>
	12	#include <asm/debug.h>
	13	#include <asm/qdio.h>
	14	#include <asm/airq.h>
	15	#include <asm/isc.h>
	16
	17	#include "cio.h"
	18	#include "ioasm.h"
	19	#include "qdio.h"
	20	#include "qdio_debug.h"
779e6e1c JG	21
	22	/*
	23	* Restriction: only 63 iqdio subchannels would have its own indicator,
	24	* after that, subsequent subchannels share one indicator
	25	*/
	26	#define TIQDIO_NR_NONSHARED_IND 63
	27	#define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
779e6e1c JG	28
	29	/* list of thin interrupt input queues */
	30	static LIST_HEAD(tiq_list);
b4547402	31	DEFINE_MUTEX(tiq_list_lock);
779e6e1c JG	32
779e6e1c JG	33	/* adapter local summary indicator */
d36deae7	34	static u8 *tiqdio_alsi;
779e6e1c	35
d36deae7	36	struct indicator_t *q_indicators;
779e6e1c	37
779e6e1c JG	38	static int css_qdio_omit_svs;
779e6e1c JG	39
d36deae7 JG	40	static u64 last_ai_time;
d36deae7 JG	41
779e6e1c JG	42	static inline unsigned long do_clear_global_summary(void)
	43	{
	44	register unsigned long __fn asm("1") = 3;
	45	register unsigned long __tmp asm("2");
	46	register unsigned long __time asm("3");
	47
	48	asm volatile(
	49	" .insn rre,0xb2650000,2,0"
	50	: "+d" (__fn), "=d" (__tmp), "=d" (__time));
	51	return __time;
	52	}
	53
	54	/* returns addr for the device state change indicator */
	55	static u32 *get_indicator(void)
	56	{
	57	int i;
	58
	59	for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++)
	60	if (!atomic_read(&q_indicators[i].count)) {
	61	atomic_set(&q_indicators[i].count, 1);
	62	return &q_indicators[i].ind;
	63	}
	64
	65	/* use the shared indicator */
	66	atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
	67	return &q_indicators[TIQDIO_SHARED_IND].ind;
	68	}
	69
	70	static void put_indicator(u32 *addr)
	71	{
	72	int i;
	73
	74	if (!addr)
	75	return;
	76	i = ((unsigned long)addr - (unsigned long)q_indicators) /
	77	sizeof(struct indicator_t);
	78	atomic_dec(&q_indicators[i].count);
	79	}
	80
	81	void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
	82	{
	83	struct qdio_q *q;
	84	int i;
	85
	86	/* No TDD facility? If we must use SIGA-s we can also omit SVS. */
	87	if (!css_qdio_omit_svs && irq_ptr->siga_flag.sync)
	88	css_qdio_omit_svs = 1;
	89
b4547402 JG	90	mutex_lock(&tiq_list_lock);
b4547402 JG	91	for_each_input_queue(irq_ptr, q, i)
779e6e1c	92	list_add_rcu(&q->entry, &tiq_list);
b4547402	93	mutex_unlock(&tiq_list_lock);
d0c9d4a8	94	xchg(irq_ptr->dsci, 1 << 7);
779e6e1c JG	95	}
779e6e1c JG	96
779e6e1c JG	97	void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
	98	{
	99	struct qdio_q *q;
	100	int i;
	101
53b41ba7 JG	102	for (i = 0; i < irq_ptr->nr_input_qs; i++) {
	103	q = irq_ptr->input_qs[i];
	104	/* if establish triggered an error */
	105	if (!q \|\| !q->entry.prev \|\| !q->entry.next)
	106	continue;
b4547402 JG	107
b4547402 JG	108	mutex_lock(&tiq_list_lock);
779e6e1c	109	list_del_rcu(&q->entry);
b4547402	110	mutex_unlock(&tiq_list_lock);
779e6e1c JG	111	synchronize_rcu();
	112	}
	113	}
	114
d36deae7	115	static inline int shared_ind_used(void)
779e6e1c	116	{
d36deae7	117	return atomic_read(&q_indicators[TIQDIO_SHARED_IND].count);
779e6e1c JG	118	}
779e6e1c JG	119
cf9a031c JG	120	/**
cf9a031c JG	121	* tiqdio_thinint_handler - thin interrupt handler for qdio
d36deae7 JG	122	* @alsi: pointer to adapter local summary indicator
d36deae7 JG	123	* @data: NULL
cf9a031c	124	*/
d36deae7	125	static void tiqdio_thinint_handler(void alsi, void data)
779e6e1c JG	126	{
	127	struct qdio_q *q;
	128
d36deae7 JG	129	last_ai_time = S390_lowcore.int_clock;
d36deae7 JG	130
cf9a031c JG	131	/*
cf9a031c JG	132	* SVS only when needed: issue SVS to benefit from iqdio interrupt
d36deae7	133	* avoidance (SVS clears adapter interrupt suppression overwrite).
cf9a031c JG	134	*/
	135	if (!css_qdio_omit_svs)
	136	do_clear_global_summary();
	137
d36deae7 JG	138	/* reset local summary indicator */
	139	if (shared_ind_used())
	140	xchg(tiqdio_alsi, 0);
779e6e1c JG	141
	142	/* protect tiq_list entries, only changed in activate or shutdown */
	143	rcu_read_lock();
	144
cf9a031c	145	/* check for work on all inbound thinint queues */
d36deae7 JG	146	list_for_each_entry_rcu(q, &tiq_list, entry) {
d36deae7 JG	147
779e6e1c	148	/* only process queues from changed sets */
d36deae7 JG	149	if (!*q->irq_ptr->dsci)
d36deae7 JG	150	continue;
779e6e1c	151
d36deae7 JG	152	if (q->u.in.queue_start_poll) {
	153	/* skip if polling is enabled or already in work */
	154	if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
	155	&q->u.in.queue_irq_state)) {
	156	qperf_inc(q, int_discarded);
	157	continue;
	158	}
	159
	160	/* avoid dsci clear here, done after processing */
	161	q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr,
	162	q->irq_ptr->int_parm);
	163	} else {
779e6e1c JG	164	/* only clear it if the indicator is non-shared */
	165	if (!shared_ind(q->irq_ptr))
	166	xchg(q->irq_ptr->dsci, 0);
	167	/*
d36deae7 JG	168	* Call inbound processing but not directly
d36deae7 JG	169	* since that could starve other thinint queues.
779e6e1c JG	170	*/
	171	tasklet_schedule(&q->tasklet);
	172	}
d36deae7 JG	173	qperf_inc(q, adapter_int);
d36deae7 JG	174	}
779e6e1c JG	175	rcu_read_unlock();
	176
	177	/*
d36deae7 JG	178	* If the shared indicator was used clear it now after all queues
d36deae7 JG	179	* were processed.
779e6e1c	180	*/
d36deae7	181	if (shared_ind_used()) {
779e6e1c JG	182	xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
	183
	184	/* prevent racing */
	185	if (*tiqdio_alsi)
d0c9d4a8	186	xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 1 << 7);
779e6e1c	187	}
779e6e1c JG	188	}
	189
	190	static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
	191	{
	192	struct scssc_area *scssc_area;
779e6e1c JG	193	int rc;
	194
	195	scssc_area = (struct scssc_area *)irq_ptr->chsc_page;
	196	memset(scssc_area, 0, PAGE_SIZE);
	197
	198	if (reset) {
	199	scssc_area->summary_indicator_addr = 0;
	200	scssc_area->subchannel_indicator_addr = 0;
	201	} else {
	202	scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi);
	203	scssc_area->subchannel_indicator_addr =
	204	virt_to_phys(irq_ptr->dsci);
	205	}
	206
	207	scssc_area->request = (struct chsc_header) {
	208	.length = 0x0fe0,
	209	.code = 0x0021,
	210	};
	211	scssc_area->operation_code = 0;
d1bf8590 HC	212	scssc_area->ks = PAGE_DEFAULT_KEY >> 4;
d1bf8590 HC	213	scssc_area->kc = PAGE_DEFAULT_KEY >> 4;
779e6e1c JG	214	scssc_area->isc = QDIO_AIRQ_ISC;
	215	scssc_area->schid = irq_ptr->schid;
	216
	217	/* enable the time delay disablement facility */
	218	if (css_general_characteristics.aif_tdd)
	219	scssc_area->word_with_d_bit = 0x10000000;
	220
	221	rc = chsc(scssc_area);
	222	if (rc)
	223	return -EIO;
	224
	225	rc = chsc_error_from_response(scssc_area->response.code);
	226	if (rc) {
22f99347 JG	227	DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
	228	scssc_area->response.code);
	229	DBF_ERROR_HEX(&scssc_area->response, sizeof(void *));
779e6e1c JG	230	return rc;
	231	}
	232
22f99347 JG	233	DBF_EVENT("setscind");
	234	DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long));
	235	DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long));
779e6e1c JG	236	return 0;
	237	}
	238
	239	/* allocate non-shared indicators and shared indicator */
	240	int __init tiqdio_allocate_memory(void)
	241	{
	242	q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
	243	GFP_KERNEL);
	244	if (!q_indicators)
	245	return -ENOMEM;
	246	return 0;
	247	}
	248
	249	void tiqdio_free_memory(void)
	250	{
	251	kfree(q_indicators);
	252	}
	253
	254	int __init tiqdio_register_thinints(void)
	255	{
779e6e1c JG	256	isc_register(QDIO_AIRQ_ISC);
	257	tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler,
	258	NULL, QDIO_AIRQ_ISC);
	259	if (IS_ERR(tiqdio_alsi)) {
22f99347	260	DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi));
779e6e1c JG	261	tiqdio_alsi = NULL;
	262	isc_unregister(QDIO_AIRQ_ISC);
	263	return -ENOMEM;
	264	}
	265	return 0;
	266	}
	267
	268	int qdio_establish_thinint(struct qdio_irq *irq_ptr)
	269	{
	270	if (!is_thinint_irq(irq_ptr))
	271	return 0;
	272
	273	/* Check for aif time delay disablement. If installed,
	274	* omit SVS even under LPAR
	275	*/
	276	if (css_general_characteristics.aif_tdd)
	277	css_qdio_omit_svs = 1;
	278	return set_subchannel_ind(irq_ptr, 0);
	279	}
	280
	281	void qdio_setup_thinint(struct qdio_irq *irq_ptr)
	282	{
	283	if (!is_thinint_irq(irq_ptr))
	284	return;
	285	irq_ptr->dsci = get_indicator();
22f99347	286	DBF_HEX(&irq_ptr->dsci, sizeof(void *));
779e6e1c JG	287	}
	288
	289	void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
	290	{
	291	if (!is_thinint_irq(irq_ptr))
	292	return;
	293
	294	/* reset adapter interrupt indicators */
	295	put_indicator(irq_ptr->dsci);
	296	set_subchannel_ind(irq_ptr, 1);
	297	}
	298
	299	void __exit tiqdio_unregister_thinints(void)
	300	{
9e890ad8	301	WARN_ON(!list_empty(&tiq_list));
779e6e1c JG	302
	303	if (tiqdio_alsi) {
	304	s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
	305	isc_unregister(QDIO_AIRQ_ISC);
	306	}
	307	}