drivers/s390/cio/qdio_thinint.c - kernel/msm - Gitiles

 /*
  * 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);
 	}
 }
	/*
	* 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);
	}
	}