Commit 5dd9ad32 authored by Juergen Gross's avatar Juergen Gross
Browse files

xen/events: drop xen_allocate_irqs_dynamic() 



Instead of having a common function for allocating a single IRQ or a
consecutive number of IRQs, split up the functionality into the callers
of xen_allocate_irqs_dynamic().

This allows to handle any allocation error in xen_irq_init() gracefully
instead of panicing the system. Let xen_irq_init() return the irq_info
pointer or NULL in case of an allocation error.

Additionally set the IRQ into irq_info already at allocation time, as
otherwise the IRQ would be '0' (which is a valid IRQ number) until
being set.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 3bdb0ac3

drivers/xen/events/events_base.c

+44 −30
Original line number Diff line number Diff line
@@ -304,6 +304,13 @@ static void channels_on_cpu_inc(struct irq_info *info) 
	info->is_accounted = 1;

}



static void xen_irq_free_desc(unsigned int irq)

{

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

	if (irq >= nr_legacy_irqs())

		irq_free_desc(irq);

}



static void delayed_free_irq(struct work_struct *work)

{

	struct irq_info *info = container_of(to_rcu_work(work), struct irq_info,
@@ -315,9 +322,7 @@ static void delayed_free_irq(struct work_struct *work) 


	kfree(info);



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

	if (irq >= nr_legacy_irqs())

		irq_free_desc(irq);

	xen_irq_free_desc(irq);

}



/* Constructors for packed IRQ information. */
@@ -332,7 +337,6 @@ static int xen_irq_info_common_setup(struct irq_info *info, 
	BUG_ON(info->type != IRQT_UNBOUND && info->type != type);



	info->type = type;

	info->irq = irq;

	info->evtchn = evtchn;

	info->cpu = cpu;

	info->mask_reason = EVT_MASK_REASON_EXPLICIT;
@@ -733,14 +737,13 @@ void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags) 
}

EXPORT_SYMBOL_GPL(xen_irq_lateeoi);



static void xen_irq_init(unsigned irq)

static struct irq_info *xen_irq_init(unsigned int irq)

{

	struct irq_info *info;



	info = kzalloc(sizeof(*info), GFP_KERNEL);

	if (info == NULL)

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



	if (info) {

		info->irq = irq;

		info->type = IRQT_UNBOUND;

		info->refcnt = -1;

		INIT_RCU_WORK(&info->rwork, delayed_free_irq);
@@ -756,22 +759,21 @@ static void xen_irq_init(unsigned irq) 
		list_add_tail(&info->list, &xen_irq_list_head);

	}



static int __must_check xen_allocate_irqs_dynamic(int nvec)

	return info;

}



static inline int __must_check xen_allocate_irq_dynamic(void)

{

	int i, irq = irq_alloc_descs(-1, 0, nvec, -1);

	int irq = irq_alloc_desc_from(0, -1);



	if (irq >= 0) {

		for (i = 0; i < nvec; i++)

			xen_irq_init(irq + i);

		if (!xen_irq_init(irq)) {

			xen_irq_free_desc(irq);

			irq = -1;

		}



	return irq;

	}



static inline int __must_check xen_allocate_irq_dynamic(void)

{



	return xen_allocate_irqs_dynamic(1);

	return irq;

}



static int __must_check xen_allocate_irq_gsi(unsigned gsi)
@@ -793,7 +795,10 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi) 
	else

		irq = irq_alloc_desc_at(gsi, -1);



	xen_irq_init(irq);

	if (!xen_irq_init(irq)) {

		xen_irq_free_desc(irq);

		irq = -1;

	}



	return irq;

}
@@ -963,6 +968,11 @@ static void __unbind_from_irq(unsigned int irq) 
	evtchn_port_t evtchn = evtchn_from_irq(irq);

	struct irq_info *info = info_for_irq(irq);



	if (!info) {

		xen_irq_free_desc(irq);

		return;

	}



	if (info->refcnt > 0) {

		info->refcnt--;

		if (info->refcnt != 0)
@@ -1101,11 +1111,14 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, 


	mutex_lock(&irq_mapping_update_lock);



	irq = xen_allocate_irqs_dynamic(nvec);

	irq = irq_alloc_descs(-1, 0, nvec, -1);

	if (irq < 0)

		goto out;



	for (i = 0; i < nvec; i++) {

		if (!xen_irq_init(irq + i))

			goto error_irq;



		irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);



		ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
@@ -1730,6 +1743,7 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq) 
	   so there should be a proper type */

	BUG_ON(info->type == IRQT_UNBOUND);



	info->irq = irq;

	(void)xen_irq_info_evtchn_setup(irq, evtchn, NULL);



	mutex_unlock(&irq_mapping_update_lock);