irqchip/gicv3-its: Cleanup for ITS domain initialization

There is no point to initialize ITS without having msi-controller
property in corresponding DT node. However, its_probe is checking
msi-controller presence at the end, so we can save our time and do that
check prior to its_probe call. Also, for the code clarity purpose,
we put domain initialization to separate function.

Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 34 insertions, 23 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 36b9c28a5c91..943442d689d8 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1614,13 +1614,37 @@ static void its_enable_quirks(struct its_node *its)
         gic_enable_quirks(iidr, its_quirks, its);
 }
 
+static int its_init_domain(struct device_node *node, struct its_node *its,
+                           struct irq_domain *parent)
+{
+        struct irq_domain *inner_domain;
+        struct msi_domain_info *info;
+
+        info = kzalloc(sizeof(*info), GFP_KERNEL);
+        if (!info)
+                return -ENOMEM;
+
+        inner_domain = irq_domain_add_tree(node, &its_domain_ops, its);
+        if (!inner_domain) {
+                kfree(info);
+                return -ENOMEM;
+        }
+
+        inner_domain->parent = parent;
+        inner_domain->bus_token = DOMAIN_BUS_NEXUS;
+        info->ops = &its_msi_domain_ops;
+        info->data = its;
+        inner_domain->host_data = info;
+
+        return 0;
+}
+
 static int __init its_probe(struct device_node *node,
                             struct irq_domain *parent)
 {
         struct resource res;
         struct its_node *its;
         void __iomem *its_base;
-        struct irq_domain *inner_domain;
         u32 val;
         u64 baser, tmp;
         int err;
@@ -1712,28 +1736,9 @@ static int __init its_probe(struct device_node *node,
         writeq_relaxed(0, its->base + GITS_CWRITER);
         writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
 
-        if (of_property_read_bool(node, "msi-controller")) {
-                struct msi_domain_info *info;
-
-                info = kzalloc(sizeof(*info), GFP_KERNEL);
-                if (!info) {
-                        err = -ENOMEM;
-                        goto out_free_tables;
-                }
-
-                inner_domain = irq_domain_add_tree(node, &its_domain_ops, its);
-                if (!inner_domain) {
-                        err = -ENOMEM;
-                        kfree(info);
-                        goto out_free_tables;
-                }
-
-                inner_domain->parent = parent;
-                inner_domain->bus_token = DOMAIN_BUS_NEXUS;
-                info->ops = &its_msi_domain_ops;
-                info->data = its;
-                inner_domain->host_data = info;
-        }
+        err = its_init_domain(node, its, parent);
+        if (err)
+                goto out_free_tables;
 
         spin_lock(&its_lock);
         list_add(&its->entry, &its_nodes);
@@ -1784,6 +1789,12 @@ int __init its_init(struct device_node *node, struct rdists *rdists,
 
         for (np = of_find_matching_node(node, its_device_id); np;
              np = of_find_matching_node(np, its_device_id)) {
+                if (!of_property_read_bool(np, "msi-controller")) {
+                        pr_warn("%s: no msi-controller property, ITS ignored\n",
+                                np->full_name);
+                        continue;
+                }
+
                 its_probe(np, parent_domain);
         }