genirq/irqdomain: Allow irq_domain_activate_irq() to fail

Allow irq_domain_activate_irq() to fail. This is required to support a
reservation and late vector assignment scheme.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.933882227@linutronix.de

include/linux/irqdomain.h

@@ -441,7 +441,7 @@ extern int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
 				   unsigned int nr_irqs, int node, void *arg,
 				   bool realloc, const struct cpumask *affinity);
 extern void irq_domain_free_irqs(unsigned int virq, unsigned int nr_irqs);
-extern void irq_domain_activate_irq(struct irq_data *irq_data);
+extern int irq_domain_activate_irq(struct irq_data *irq_data);
 extern void irq_domain_deactivate_irq(struct irq_data *irq_data);
 
 static inline int irq_domain_alloc_irqs(struct irq_domain *domain,

kernel/irq/chip.c

@@ -219,7 +219,12 @@ __irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
 		 */
 		return IRQ_STARTUP_ABORT;
 	}
-	irq_domain_activate_irq(d);
+	/*
+	 * Managed interrupts have reserved resources, so this should not
+	 * happen.
+	 */
+	if (WARN_ON(irq_domain_activate_irq(d)))
+		return IRQ_STARTUP_ABORT;
 	return IRQ_STARTUP_MANAGED;
 }
 #else
@@ -285,7 +290,7 @@ int irq_activate(struct irq_desc *desc)
 	struct irq_data *d = irq_desc_get_irq_data(desc);
 
 	if (!irqd_affinity_is_managed(d))
-		irq_domain_activate_irq(d);
+		return irq_domain_activate_irq(d);
 	return 0;
 }
 

kernel/irq/internals.h

@@ -439,9 +439,10 @@ static inline bool irq_fixup_move_pending(struct irq_desc *desc, bool fclear)
 #endif /* !CONFIG_GENERIC_PENDING_IRQ */
 
 #if !defined(CONFIG_IRQ_DOMAIN) || !defined(CONFIG_IRQ_DOMAIN_HIERARCHY)
-static inline void irq_domain_activate_irq(struct irq_data *data)
+static inline int irq_domain_activate_irq(struct irq_data *data)
 {
 	irqd_set_activated(data);
+	return 0;
 }
 static inline void irq_domain_deactivate_irq(struct irq_data *data)
 {

kernel/irq/irqdomain.c

@@ -1682,18 +1682,6 @@ void irq_domain_free_irqs_parent(struct irq_domain *domain,
 }
 EXPORT_SYMBOL_GPL(irq_domain_free_irqs_parent);
 
-static void __irq_domain_activate_irq(struct irq_data *irq_data)
-{
-	if (irq_data && irq_data->domain) {
-		struct irq_domain *domain = irq_data->domain;
-
-		if (irq_data->parent_data)
-			__irq_domain_activate_irq(irq_data->parent_data);
-		if (domain->ops->activate)
-			domain->ops->activate(domain, irq_data, false);
-	}
-}
-
 static void __irq_domain_deactivate_irq(struct irq_data *irq_data)
 {
 	if (irq_data && irq_data->domain) {
@@ -1706,6 +1694,25 @@ static void __irq_domain_deactivate_irq(struct irq_data *irq_data)
 	}
 }
 
+static int __irq_domain_activate_irq(struct irq_data *irqd)
+{
+	int ret = 0;
+
+	if (irqd && irqd->domain) {
+		struct irq_domain *domain = irqd->domain;
+
+		if (irqd->parent_data)
+			ret = __irq_domain_activate_irq(irqd->parent_data);
+		if (!ret && domain->ops->activate) {
+			ret = domain->ops->activate(domain, irqd, false);
+			/* Rollback in case of error */
+			if (ret && irqd->parent_data)
+				__irq_domain_deactivate_irq(irqd->parent_data);
+		}
+	}
+	return ret;
+}
+
 /**
  * irq_domain_activate_irq - Call domain_ops->activate recursively to activate
  *			     interrupt
@@ -1714,12 +1721,15 @@ static void __irq_domain_deactivate_irq(struct irq_data *irq_data)
  * This is the second step to call domain_ops->activate to program interrupt
  * controllers, so the interrupt could actually get delivered.
  */
-void irq_domain_activate_irq(struct irq_data *irq_data)
+int irq_domain_activate_irq(struct irq_data *irq_data)
 {
-	if (!irqd_is_activated(irq_data)) {
-		__irq_domain_activate_irq(irq_data);
+	int ret = 0;
+
+	if (!irqd_is_activated(irq_data))
+		ret = __irq_domain_activate_irq(irq_data);
+	if (!ret)
 		irqd_set_activated(irq_data);
-	}
+	return ret;
 }
 
 /**

kernel/irq/msi.c

@@ -401,11 +401,26 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 			struct irq_data *irq_data;
 
 			irq_data = irq_domain_get_irq_data(domain, desc->irq);
-			irq_domain_activate_irq(irq_data);
+			ret = irq_domain_activate_irq(irq_data);
+			if (ret)
+				goto cleanup;
 		}
 	}
-
 	return 0;
+
+cleanup:
+	for_each_msi_entry(desc, dev) {
+		struct irq_data *irqd;
+
+		if (desc->irq == virq)
+			break;
+
+		irqd = irq_domain_get_irq_data(domain, desc->irq);
+		if (irqd_is_activated(irqd))
+			irq_domain_deactivate_irq(irqd);
+	}
+	msi_domain_free_irqs(domain, dev);
+	return ret;
 }
 
 /**