[linux-2.6-block.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)
#define TIQDIO_SHARED_IND		63

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

/* 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 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;

	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(struct qdio_irq *irq_ptr)
{
	return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
}

/**
 * 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)
{
	struct qdio_q *q;

	/*
	 * 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
	 */
	xchg((u8 *)ind, 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) {
			qperf_inc(q, adapter_int);

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