[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / s390 / cio / qdio_thinint.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);
	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;

	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;
	inc_irq_stat(IRQIO_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);
	}
}
Commit	Line	Data
779e6e1c	1	/*
a53c8fab	2	* Copyright IBM Corp. 2000, 2009
779e6e1c JG	3	* Author(s): Utz Bacher <utz.bacher@de.ibm.com>
	4	* Cornelia Huck <cornelia.huck@de.ibm.com>
	5	* Jan Glauber <jang@linux.vnet.ibm.com>
	6	*/
	7	#include <linux/io.h>
5a0e3ad6	8	#include <linux/slab.h>
30d77c3e	9	#include <linux/kernel_stat.h>
60063497	10	#include <linux/atomic.h>
779e6e1c JG	11	#include <asm/debug.h>
	12	#include <asm/qdio.h>
	13	#include <asm/airq.h>
	14	#include <asm/isc.h>
	15
	16	#include "cio.h"
	17	#include "ioasm.h"
	18	#include "qdio.h"
	19	#include "qdio_debug.h"
779e6e1c JG	20
	21	/*
	22	* Restriction: only 63 iqdio subchannels would have its own indicator,
	23	* after that, subsequent subchannels share one indicator
	24	*/
	25	#define TIQDIO_NR_NONSHARED_IND 63
	26	#define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
5f4026f8 JG	27	#define TIQDIO_SHARED_IND 63
	28
	29	/* device state change indicators */
	30	struct indicator_t {
	31	u32 ind; /* u32 because of compare-and-swap performance */
	32	atomic_t count; /* use count, 0 or 1 for non-shared indicators */
	33	};
779e6e1c JG	34
	35	/* list of thin interrupt input queues */
	36	static LIST_HEAD(tiq_list);
c4736d96	37	static DEFINE_MUTEX(tiq_list_lock);
779e6e1c JG	38
779e6e1c JG	39	/* adapter local summary indicator */
d36deae7	40	static u8 *tiqdio_alsi;
779e6e1c	41
5f4026f8	42	static struct indicator_t *q_indicators;
779e6e1c	43
a2b86019	44	u64 last_ai_time;
d36deae7	45
779e6e1c JG	46	/* returns addr for the device state change indicator */
	47	static u32 *get_indicator(void)
	48	{
	49	int i;
	50
	51	for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++)
	52	if (!atomic_read(&q_indicators[i].count)) {
	53	atomic_set(&q_indicators[i].count, 1);
	54	return &q_indicators[i].ind;
	55	}
	56
	57	/* use the shared indicator */
	58	atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
	59	return &q_indicators[TIQDIO_SHARED_IND].ind;
	60	}
	61
	62	static void put_indicator(u32 *addr)
	63	{
	64	int i;
	65
	66	if (!addr)
	67	return;
	68	i = ((unsigned long)addr - (unsigned long)q_indicators) /
	69	sizeof(struct indicator_t);
	70	atomic_dec(&q_indicators[i].count);
	71	}
	72
	73	void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
	74	{
b4547402	75	mutex_lock(&tiq_list_lock);
104ea556	76	list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list);
b4547402	77	mutex_unlock(&tiq_list_lock);
d0c9d4a8	78	xchg(irq_ptr->dsci, 1 << 7);
779e6e1c JG	79	}
779e6e1c JG	80
779e6e1c JG	81	void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
	82	{
	83	struct qdio_q *q;
779e6e1c	84
104ea556	85	q = irq_ptr->input_qs[0];
	86	/* if establish triggered an error */
	87	if (!q \|\| !q->entry.prev \|\| !q->entry.next)
	88	return;
b4547402	89
104ea556	90	mutex_lock(&tiq_list_lock);
	91	list_del_rcu(&q->entry);
	92	mutex_unlock(&tiq_list_lock);
	93	synchronize_rcu();
779e6e1c JG	94	}
779e6e1c JG	95
5f4026f8 JG	96	static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr)
	97	{
	98	return irq_ptr->nr_input_qs > 1;
	99	}
	100
	101	static inline int references_shared_dsci(struct qdio_irq *irq_ptr)
	102	{
	103	return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
	104	}
	105
	106	static inline int shared_ind(struct qdio_irq *irq_ptr)
	107	{
	108	return references_shared_dsci(irq_ptr) \|\|
	109	has_multiple_inq_on_dsci(irq_ptr);
	110	}
	111
	112	void clear_nonshared_ind(struct qdio_irq *irq_ptr)
	113	{
	114	if (!is_thinint_irq(irq_ptr))
	115	return;
	116	if (shared_ind(irq_ptr))
	117	return;
	118	xchg(irq_ptr->dsci, 0);
	119	}
	120
	121	int test_nonshared_ind(struct qdio_irq *irq_ptr)
	122	{
	123	if (!is_thinint_irq(irq_ptr))
	124	return 0;
	125	if (shared_ind(irq_ptr))
	126	return 0;
	127	if (*irq_ptr->dsci)
	128	return 1;
	129	else
	130	return 0;
	131	}
	132
b02f0c2e	133	static inline u32 clear_shared_ind(void)
779e6e1c	134	{
b02f0c2e JG	135	if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count))
	136	return 0;
	137	return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
779e6e1c JG	138	}
779e6e1c JG	139
104ea556	140	static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq)
	141	{
	142	struct qdio_q *q;
	143	int i;
	144
	145	for_each_input_queue(irq, q, i) {
	146	if (!references_shared_dsci(irq) &&
	147	has_multiple_inq_on_dsci(irq))
	148	xchg(q->irq_ptr->dsci, 0);
	149
	150	if (q->u.in.queue_start_poll) {
	151	/* skip if polling is enabled or already in work */
	152	if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
	153	&q->u.in.queue_irq_state)) {
	154	qperf_inc(q, int_discarded);
	155	continue;
	156	}
	157
	158	/* avoid dsci clear here, done after processing */
	159	q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr,
	160	q->irq_ptr->int_parm);
	161	} else {
5f4026f8	162	if (!shared_ind(q->irq_ptr))
104ea556	163	xchg(q->irq_ptr->dsci, 0);
	164
	165	/*
	166	* Call inbound processing but not directly
	167	* since that could starve other thinint queues.
	168	*/
	169	tasklet_schedule(&q->tasklet);
	170	}
	171	}
	172	}
	173
cf9a031c JG	174	/**
cf9a031c JG	175	* tiqdio_thinint_handler - thin interrupt handler for qdio
d36deae7 JG	176	* @alsi: pointer to adapter local summary indicator
d36deae7 JG	177	* @data: NULL
cf9a031c	178	*/
d36deae7	179	static void tiqdio_thinint_handler(void alsi, void data)
779e6e1c	180	{
b02f0c2e	181	u32 si_used = clear_shared_ind();
779e6e1c JG	182	struct qdio_q *q;
779e6e1c JG	183
d36deae7	184	last_ai_time = S390_lowcore.int_clock;
420f42ec	185	inc_irq_stat(IRQIO_QAI);
d36deae7	186
779e6e1c JG	187	/* protect tiq_list entries, only changed in activate or shutdown */
	188	rcu_read_lock();
	189
cf9a031c	190	/* check for work on all inbound thinint queues */
d36deae7	191	list_for_each_entry_rcu(q, &tiq_list, entry) {
104ea556	192	struct qdio_irq *irq;
d36deae7	193
779e6e1c	194	/* only process queues from changed sets */
104ea556	195	irq = q->irq_ptr;
104ea556	196	if (unlikely(references_shared_dsci(irq))) {
4f325184 JG	197	if (!si_used)
4f325184 JG	198	continue;
104ea556	199	} else if (!*irq->dsci)
d36deae7	200	continue;
779e6e1c	201
104ea556	202	tiqdio_call_inq_handlers(irq);
d36deae7	203
d36deae7 JG	204	qperf_inc(q, adapter_int);
d36deae7 JG	205	}
779e6e1c	206	rcu_read_unlock();
779e6e1c JG	207	}
	208
	209	static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
	210	{
	211	struct scssc_area *scssc_area;
779e6e1c JG	212	int rc;
	213
	214	scssc_area = (struct scssc_area *)irq_ptr->chsc_page;
	215	memset(scssc_area, 0, PAGE_SIZE);
	216
	217	if (reset) {
	218	scssc_area->summary_indicator_addr = 0;
	219	scssc_area->subchannel_indicator_addr = 0;
	220	} else {
	221	scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi);
	222	scssc_area->subchannel_indicator_addr =
	223	virt_to_phys(irq_ptr->dsci);
	224	}
	225
	226	scssc_area->request = (struct chsc_header) {
	227	.length = 0x0fe0,
	228	.code = 0x0021,
	229	};
	230	scssc_area->operation_code = 0;
d1bf8590 HC	231	scssc_area->ks = PAGE_DEFAULT_KEY >> 4;
d1bf8590 HC	232	scssc_area->kc = PAGE_DEFAULT_KEY >> 4;
779e6e1c JG	233	scssc_area->isc = QDIO_AIRQ_ISC;
	234	scssc_area->schid = irq_ptr->schid;
	235
	236	/* enable the time delay disablement facility */
	237	if (css_general_characteristics.aif_tdd)
	238	scssc_area->word_with_d_bit = 0x10000000;
	239
	240	rc = chsc(scssc_area);
	241	if (rc)
	242	return -EIO;
	243
	244	rc = chsc_error_from_response(scssc_area->response.code);
	245	if (rc) {
22f99347 JG	246	DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
	247	scssc_area->response.code);
	248	DBF_ERROR_HEX(&scssc_area->response, sizeof(void *));
779e6e1c JG	249	return rc;
	250	}
	251
22f99347 JG	252	DBF_EVENT("setscind");
	253	DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long));
	254	DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long));
779e6e1c JG	255	return 0;
	256	}
	257
	258	/* allocate non-shared indicators and shared indicator */
	259	int __init tiqdio_allocate_memory(void)
	260	{
	261	q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
	262	GFP_KERNEL);
	263	if (!q_indicators)
	264	return -ENOMEM;
	265	return 0;
	266	}
	267
	268	void tiqdio_free_memory(void)
	269	{
	270	kfree(q_indicators);
	271	}
	272
	273	int __init tiqdio_register_thinints(void)
	274	{
779e6e1c JG	275	isc_register(QDIO_AIRQ_ISC);
	276	tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler,
	277	NULL, QDIO_AIRQ_ISC);
	278	if (IS_ERR(tiqdio_alsi)) {
22f99347	279	DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi));
779e6e1c JG	280	tiqdio_alsi = NULL;
	281	isc_unregister(QDIO_AIRQ_ISC);
	282	return -ENOMEM;
	283	}
	284	return 0;
	285	}
	286
	287	int qdio_establish_thinint(struct qdio_irq *irq_ptr)
	288	{
	289	if (!is_thinint_irq(irq_ptr))
	290	return 0;
779e6e1c JG	291	return set_subchannel_ind(irq_ptr, 0);
	292	}
	293
	294	void qdio_setup_thinint(struct qdio_irq *irq_ptr)
	295	{
	296	if (!is_thinint_irq(irq_ptr))
	297	return;
	298	irq_ptr->dsci = get_indicator();
22f99347	299	DBF_HEX(&irq_ptr->dsci, sizeof(void *));
779e6e1c JG	300	}
	301
	302	void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
	303	{
	304	if (!is_thinint_irq(irq_ptr))
	305	return;
	306
	307	/* reset adapter interrupt indicators */
779e6e1c	308	set_subchannel_ind(irq_ptr, 1);
4814a2b3	309	put_indicator(irq_ptr->dsci);
779e6e1c JG	310	}
	311
	312	void __exit tiqdio_unregister_thinints(void)
	313	{
9e890ad8	314	WARN_ON(!list_empty(&tiq_list));
779e6e1c JG	315
	316	if (tiqdio_alsi) {
	317	s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
	318	isc_unregister(QDIO_AIRQ_ISC);
	319	}
	320	}