genirq: Move irq_has_action() into core code

[linux-2.6-microblaze.git] / kernel / irq / manage.c

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c460e04..a5a1cde 100644 (file)
--- 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);
@@ -2752,3 +2822,20 @@ out_unlock:
        return err;
 }
 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
+
+/**
+ * irq_has_action - Check whether an interrupt is requested
+ * @irq:       The linux irq number
+ *
+ * Returns: A snapshot of the current state
+ */
+bool irq_has_action(unsigned int irq)
+{
+       bool res;
+
+       rcu_read_lock();
+       res = irq_desc_has_action(irq_to_desc(irq));
+       rcu_read_unlock();
+       return res;
+}
+EXPORT_SYMBOL_GPL(irq_has_action);