[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 <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);
}

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);
	}
}

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