linux-kernel - [PATCH v2 1/4] irqdomain: Look for existing mapping only once

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Message-Id: <20220901142816.13731-2-johan+linaro@kernel.org>
Date:   Thu,  1 Sep 2022 16:28:13 +0200
From:   Johan Hovold <johan+linaro@...nel.org>
To:     Marc Zyngier <maz@...nel.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Rob Herring <robh@...nel.org>, linux-kernel@...r.kernel.org,
        Johan Hovold <johan+linaro@...nel.org>
Subject: [PATCH v2 1/4] irqdomain: Look for existing mapping only once

Avoid looking for an existing mapping twice when creating a new mapping
using irq_create_fwspec_mapping() by factoring out the actual allocation
which is shared with irq_create_mapping_affinity().

Signed-off-by: Johan Hovold <johan+linaro@...nel.org>
---
 kernel/irq/irqdomain.c | 60 +++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 8fe1da9614ee..24ddd8d9b597 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -668,6 +668,34 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
 EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
 #endif
 
+static unsigned int __irq_create_mapping_affinity(struct irq_domain *domain,
+						  irq_hw_number_t hwirq,
+						  const struct irq_affinity_desc *affinity)
+{
+	struct device_node *of_node = irq_domain_get_of_node(domain);
+	int virq;
+
+	pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
+
+	/* Allocate a virtual interrupt number */
+	virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node),
+				      affinity);
+	if (virq <= 0) {
+		pr_debug("-> virq allocation failed\n");
+		return 0;
+	}
+
+	if (irq_domain_associate(domain, virq, hwirq)) {
+		irq_free_desc(virq);
+		return 0;
+	}
+
+	pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
+		hwirq, of_node_full_name(of_node), virq);
+
+	return virq;
+}
+
 /**
  * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space
  * @domain: domain owning this hardware interrupt or NULL for default domain
@@ -680,14 +708,11 @@ EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
  * on the number returned from that call.
  */
 unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
-				       irq_hw_number_t hwirq,
-				       const struct irq_affinity_desc *affinity)
+					 irq_hw_number_t hwirq,
+					 const struct irq_affinity_desc *affinity)
 {
-	struct device_node *of_node;
 	int virq;
 
-	pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
-
 	/* Look for default domain if necessary */
 	if (domain == NULL)
 		domain = irq_default_domain;
@@ -695,34 +720,15 @@ unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
 		WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
 		return 0;
 	}
-	pr_debug("-> using domain @%p\n", domain);
-
-	of_node = irq_domain_get_of_node(domain);
 
 	/* Check if mapping already exists */
 	virq = irq_find_mapping(domain, hwirq);
 	if (virq) {
-		pr_debug("-> existing mapping on virq %d\n", virq);
+		pr_debug("existing mapping on virq %d\n", virq);
 		return virq;
 	}
 
-	/* Allocate a virtual interrupt number */
-	virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node),
-				      affinity);
-	if (virq <= 0) {
-		pr_debug("-> virq allocation failed\n");
-		return 0;
-	}
-
-	if (irq_domain_associate(domain, virq, hwirq)) {
-		irq_free_desc(virq);
-		return 0;
-	}
-
-	pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
-		hwirq, of_node_full_name(of_node), virq);
-
-	return virq;
+	return __irq_create_mapping_affinity(domain, hwirq, affinity);
 }
 EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);
 
@@ -827,7 +833,7 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
 			return 0;
 	} else {
 		/* Create mapping */
-		virq = irq_create_mapping(domain, hwirq);
+		virq = __irq_create_mapping_affinity(domain, hwirq, NULL);
 		if (!virq)
 			return virq;
 	}
-- 
2.35.1