Commit d55f7f4c authored by Johan Hovold's avatar Johan Hovold Committed by Marc Zyngier
Browse files

irqdomain: Refactor __irq_domain_alloc_irqs() 



Refactor __irq_domain_alloc_irqs() so that it can be called internally
while holding the irq_domain_mutex.

This will be used to fix a shared-interrupt mapping race, hence the
Fixes tag.

Fixes: b62b2cf5 ("irqdomain: Fix handling of type settings for existing mappings")
Cc: stable@vger.kernel.org      # 4.8
Tested-by: default avatarHsin-Yi Wang <hsinyi@chromium.org>
Tested-by: default avatarMark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: default avatarJohan Hovold <johan+linaro@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-6-johan+linaro@kernel.org
parent 6e6f75c9

kernel/irq/irqdomain.c

+48 −40
Original line number Diff line number Diff line
@@ -1441,40 +1441,12 @@ int irq_domain_alloc_irqs_hierarchy(struct irq_domain *domain, 
	return domain->ops->alloc(domain, irq_base, nr_irqs, arg);

}



/**

 * __irq_domain_alloc_irqs - Allocate IRQs from domain

 * @domain:	domain to allocate from

 * @irq_base:	allocate specified IRQ number if irq_base >= 0

 * @nr_irqs:	number of IRQs to allocate

 * @node:	NUMA node id for memory allocation

 * @arg:	domain specific argument

 * @realloc:	IRQ descriptors have already been allocated if true

 * @affinity:	Optional irq affinity mask for multiqueue devices

 *

 * Allocate IRQ numbers and initialized all data structures to support

 * hierarchy IRQ domains.

 * Parameter @realloc is mainly to support legacy IRQs.

 * Returns error code or allocated IRQ number

 *

 * The whole process to setup an IRQ has been split into two steps.

 * The first step, __irq_domain_alloc_irqs(), is to allocate IRQ

 * descriptor and required hardware resources. The second step,

 * irq_domain_activate_irq(), is to program the hardware with preallocated

 * resources. In this way, it's easier to rollback when failing to

 * allocate resources.

 */

int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,

static int irq_domain_alloc_irqs_locked(struct irq_domain *domain, int irq_base,

					unsigned int nr_irqs, int node, void *arg,

					bool realloc, const struct irq_affinity_desc *affinity)

{

	int i, ret, virq;



	if (domain == NULL) {

		domain = irq_default_domain;

		if (WARN(!domain, "domain is NULL; cannot allocate IRQ\n"))

			return -EINVAL;

	}



	if (realloc && irq_base >= 0) {

		virq = irq_base;

	} else {
@@ -1493,24 +1465,18 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base, 
		goto out_free_desc;

	}



	mutex_lock(&irq_domain_mutex);

	ret = irq_domain_alloc_irqs_hierarchy(domain, virq, nr_irqs, arg);

	if (ret < 0) {

		mutex_unlock(&irq_domain_mutex);

	if (ret < 0)

		goto out_free_irq_data;

	}



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

		ret = irq_domain_trim_hierarchy(virq + i);

		if (ret) {

			mutex_unlock(&irq_domain_mutex);

		if (ret)

			goto out_free_irq_data;

	}

	}



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

		irq_domain_insert_irq(virq + i);

	mutex_unlock(&irq_domain_mutex);



	return virq;
@@ -1520,6 +1486,48 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base, 
	irq_free_descs(virq, nr_irqs);

	return ret;

}



/**

 * __irq_domain_alloc_irqs - Allocate IRQs from domain

 * @domain:	domain to allocate from

 * @irq_base:	allocate specified IRQ number if irq_base >= 0

 * @nr_irqs:	number of IRQs to allocate

 * @node:	NUMA node id for memory allocation

 * @arg:	domain specific argument

 * @realloc:	IRQ descriptors have already been allocated if true

 * @affinity:	Optional irq affinity mask for multiqueue devices

 *

 * Allocate IRQ numbers and initialized all data structures to support

 * hierarchy IRQ domains.

 * Parameter @realloc is mainly to support legacy IRQs.

 * Returns error code or allocated IRQ number

 *

 * The whole process to setup an IRQ has been split into two steps.

 * The first step, __irq_domain_alloc_irqs(), is to allocate IRQ

 * descriptor and required hardware resources. The second step,

 * irq_domain_activate_irq(), is to program the hardware with preallocated

 * resources. In this way, it's easier to rollback when failing to

 * allocate resources.

 */

int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,

			    unsigned int nr_irqs, int node, void *arg,

			    bool realloc, const struct irq_affinity_desc *affinity)

{

	int ret;



	if (domain == NULL) {

		domain = irq_default_domain;

		if (WARN(!domain, "domain is NULL; cannot allocate IRQ\n"))

			return -EINVAL;

	}



	mutex_lock(&irq_domain_mutex);

	ret = irq_domain_alloc_irqs_locked(domain, irq_base, nr_irqs, node, arg,

					   realloc, affinity);

	mutex_unlock(&irq_domain_mutex);



	return ret;

}

EXPORT_SYMBOL_GPL(__irq_domain_alloc_irqs);



/* The irq_data was moved, fix the revmap to refer to the new location */