diff options
| -rw-r--r-- | include/linux/interrupt.h | 8 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 70 |
2 files changed, 78 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index ee8299eb1f52..870b3251e174 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -352,6 +352,8 @@ extern int irq_can_set_affinity(unsigned int irq); extern int irq_select_affinity(unsigned int irq); extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); +extern int irq_update_affinity_desc(unsigned int irq, + struct irq_affinity_desc *affinity); extern int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); @@ -387,6 +389,12 @@ static inline int irq_set_affinity_hint(unsigned int irq, return -EINVAL; } +static inline int irq_update_affinity_desc(unsigned int irq, + struct irq_affinity_desc *affinity) +{ + return -EINVAL; +} + static inline int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) { diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index c460e0496006..c826ba4141fe 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -371,6 +371,76 @@ int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, return ret; } +/** + * irq_update_affinity_desc - Update affinity management for an interrupt + * @irq: The interrupt number to update + * @affinity: Pointer to the affinity descriptor + * + * This interface can be used to configure the affinity management of + * interrupts which have been allocated already. + * + * There are certain limitations on when it may be used - attempts to use it + * for when the kernel is configured for generic IRQ reservation mode (in + * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with + * managed/non-managed interrupt accounting. In addition, attempts to use it on + * an interrupt which is already started or which has already been configured + * as managed will also fail, as these mean invalid init state or double init. + */ +int irq_update_affinity_desc(unsigned int irq, + struct irq_affinity_desc *affinity) +{ + struct irq_desc *desc; + unsigned long flags; + bool activated; + int ret = 0; + + /* + * Supporting this with the reservation scheme used by x86 needs + * some more thought. Fail it for now. + */ + if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE)) + return -EOPNOTSUPP; + + desc = irq_get_desc_buslock(irq, &flags, 0); + if (!desc) + return -EINVAL; + + /* Requires the interrupt to be shut down */ + if (irqd_is_started(&desc->irq_data)) { + ret = -EBUSY; + goto out_unlock; + } + + /* Interrupts which are already managed cannot be modified */ + if (irqd_affinity_is_managed(&desc->irq_data)) { + ret = -EBUSY; + goto out_unlock; + } + + /* + * Deactivate the interrupt. That's required to undo + * anything an earlier activation has established. + */ + activated = irqd_is_activated(&desc->irq_data); + if (activated) + irq_domain_deactivate_irq(&desc->irq_data); + + if (affinity->is_managed) { + irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED); + irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN); + } + + cpumask_copy(desc->irq_common_data.affinity, &affinity->mask); + + /* Restore the activation state */ + if (activated) + irq_domain_activate_irq(&desc->irq_data, false); + +out_unlock: + irq_put_desc_busunlock(desc, flags); + return ret; +} + int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force) { struct irq_desc *desc = irq_to_desc(irq); |