Commit 6cb6537d authored by Ian Campbell's avatar Ian Campbell Committed by Konrad Rzeszutek Wilk
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xen: events: maintain a list of Xen interrupts 



In a PVHVM kernel not all interrupts are Xen interrupts (APIC interrupts can also be present).

Currently we get away with walking over all interrupts because the
lookup in the irq_info array simply returns IRQT_UNBOUND and we ignore
it. However this array will be going away in a future patch so we need
to manually track which interrupts have been allocated by the Xen
events infrastructure.

Signed-off-by: default avatarIan Campbell <ian.campbell@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 3d4cfa37

drivers/xen/events.c

+44 −15
Original line number Original line Diff line number Diff line
@@ -56,6 +56,8 @@ 
 */

 */

static DEFINE_SPINLOCK(irq_mapping_update_lock);

static DEFINE_SPINLOCK(irq_mapping_update_lock);





static LIST_HEAD(xen_irq_list_head);



/* IRQ <-> VIRQ mapping. */

/* IRQ <-> VIRQ mapping. */

static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};

static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
@@ -85,7 +87,9 @@ enum xen_irq_type { 
 */

 */

struct irq_info

struct irq_info

{

{

	struct list_head list;

	enum xen_irq_type type;	/* type */

	enum xen_irq_type type;	/* type */

	unsigned irq;

	unsigned short evtchn;	/* event channel */

	unsigned short evtchn;	/* event channel */

	unsigned short cpu;	/* cpu bound */

	unsigned short cpu;	/* cpu bound */
@@ -135,6 +139,7 @@ static void xen_irq_info_common_init(struct irq_info *info, 
	BUG_ON(info->type != IRQT_UNBOUND && info->type != type);

	BUG_ON(info->type != IRQT_UNBOUND && info->type != type);





	info->type = type;

	info->type = type;

	info->irq = irq;

	info->evtchn = evtchn;

	info->evtchn = evtchn;

	info->cpu = cpu;

	info->cpu = cpu;
@@ -311,10 +316,11 @@ static void init_evtchn_cpu_bindings(void) 
{

{

	int i;

	int i;

#ifdef CONFIG_SMP

#ifdef CONFIG_SMP

	struct irq_desc *desc;

	struct irq_info *info;





	/* By default all event channels notify CPU#0. */

	/* By default all event channels notify CPU#0. */

	for_each_irq_desc(i, desc) {

	list_for_each_entry(info, &xen_irq_list_head, list) {

		struct irq_desc *desc = irq_to_desc(info->irq);

		cpumask_copy(desc->irq_data.affinity, cpumask_of(0));

		cpumask_copy(desc->irq_data.affinity, cpumask_of(0));

	}

	}

#endif

#endif
@@ -397,6 +403,21 @@ static void unmask_evtchn(int port) 
	put_cpu();

	put_cpu();

}

}





static void xen_irq_init(unsigned irq)

{

	struct irq_info *info;

	struct irq_desc *desc = irq_to_desc(irq);



	/* By default all event channels notify CPU#0. */

	cpumask_copy(desc->irq_data.affinity, cpumask_of(0));



	info = &irq_info[irq];



	info->type = IRQT_UNBOUND;



	list_add_tail(&info->list, &xen_irq_list_head);

}



static int xen_allocate_irq_dynamic(void)

static int xen_allocate_irq_dynamic(void)

{

{

	int first = 0;

	int first = 0;
@@ -426,6 +447,8 @@ static int xen_allocate_irq_dynamic(void) 
	if (irq < 0)

	if (irq < 0)

		panic("No available IRQ to bind to: increase nr_irqs!\n");

		panic("No available IRQ to bind to: increase nr_irqs!\n");





	xen_irq_init(irq);



	return irq;

	return irq;

}

}
@@ -444,18 +467,25 @@ static int xen_allocate_irq_gsi(unsigned gsi) 




	/* Legacy IRQ descriptors are already allocated by the arch. */

	/* Legacy IRQ descriptors are already allocated by the arch. */

	if (gsi < NR_IRQS_LEGACY)

	if (gsi < NR_IRQS_LEGACY)

		return gsi;

		irq = gsi;



	else

		irq = irq_alloc_desc_at(gsi, -1);

		irq = irq_alloc_desc_at(gsi, -1);



	if (irq < 0)

	if (irq < 0)

		panic("Unable to allocate to IRQ%d (%d)\n", gsi, irq);

		panic("Unable to allocate to IRQ%d (%d)\n", gsi, irq);





	xen_irq_init(irq);



	return irq;

	return irq;

}

}





static void xen_free_irq(unsigned irq)

static void xen_free_irq(unsigned irq)

{

{

	irq_info[irq].type = IRQT_UNBOUND;

	struct irq_info *info = &irq_info[irq];



	info->type = IRQT_UNBOUND;



	list_del(&info->list);





	/* Legacy IRQ descriptors are managed by the arch. */

	/* Legacy IRQ descriptors are managed by the arch. */

	if (irq < NR_IRQS_LEGACY)

	if (irq < NR_IRQS_LEGACY)
@@ -586,16 +616,14 @@ static void ack_pirq(struct irq_data *data) 




static int find_irq_by_gsi(unsigned gsi)

static int find_irq_by_gsi(unsigned gsi)

{

{

	int irq;

	struct irq_info *info;





	for (irq = 0; irq < nr_irqs; irq++) {

	list_for_each_entry(info, &xen_irq_list_head, list) {

		struct irq_info *info = info_for_irq(irq);

		if (info->type != IRQT_PIRQ)



		if (info == NULL || info->type != IRQT_PIRQ)

			continue;

			continue;





		if (gsi_from_irq(irq) == gsi)

		if (info->u.pirq.gsi == gsi)

			return irq;

			return info->irq;

	}

	}





	return -1;

	return -1;
@@ -1374,7 +1402,8 @@ void xen_poll_irq(int irq) 




void xen_irq_resume(void)

void xen_irq_resume(void)

{

{

	unsigned int cpu, irq, evtchn;

	unsigned int cpu, evtchn;

	struct irq_info *info;





	init_evtchn_cpu_bindings();

	init_evtchn_cpu_bindings();
@@ -1383,8 +1412,8 @@ void xen_irq_resume(void) 
		mask_evtchn(evtchn);

		mask_evtchn(evtchn);





	/* No IRQ <-> event-channel mappings. */

	/* No IRQ <-> event-channel mappings. */

	for (irq = 0; irq < nr_irqs; irq++)

	list_for_each_entry(info, &xen_irq_list_head, list)

		irq_info[irq].evtchn = 0; /* zap event-channel binding */

		info->evtchn = 0; /* zap event-channel binding */





	for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)

	for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)

		evtchn_to_irq[evtchn] = -1;

		evtchn_to_irq[evtchn] = -1;