irqchip/gic: Switch ACPI support to stacked domains

Now that the basic ACPI GSI code is irq domain aware, make sure
that the ACPI support in the GIC doesn't pointlessly deviate from
the DT path.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-and-tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Graeme Gregory <graeme@xora.org.uk>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/1444737105-31573-13-git-send-email-marc.zyngier@arm.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/irqchip/irq-gic.c

@@ -963,6 +963,15 @@ static int gic_irq_domain_translate(struct irq_domain *d,
 		return 0;
 	}
 
+	if (fwspec->fwnode->type == FWNODE_IRQCHIP) {
+		if(fwspec->param_count != 2)
+			return -EINVAL;
+
+		*hwirq = fwspec->param[0];
+		*type = fwspec->param[1];
+		return 0;
+	}
+
 	return -EINVAL;
 }
 
@@ -1017,7 +1026,7 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
 
 static void __init __gic_init_bases(unsigned int gic_nr, int irq_start,
 			   void __iomem *dist_base, void __iomem *cpu_base,
-			   u32 percpu_offset, struct device_node *node)
+			   u32 percpu_offset, struct fwnode_handle *handle)
 {
 	irq_hw_number_t hwirq_base;
 	struct gic_chip_data *gic;
@@ -1071,11 +1080,11 @@ static void __init __gic_init_bases(unsigned int gic_nr, int irq_start,
 		gic_irqs = 1020;
 	gic->gic_irqs = gic_irqs;
 
-	if (node) {		/* DT case */
-		gic->domain = irq_domain_add_linear(node, gic_irqs,
-						    &gic_irq_domain_hierarchy_ops,
-						    gic);
-	} else {		/* Non-DT case */
+	if (handle) {		/* DT/ACPI */
+		gic->domain = irq_domain_create_linear(handle, gic_irqs,
+						       &gic_irq_domain_hierarchy_ops,
+						       gic);
+	} else {		/* Legacy support */
 		/*
 		 * For primary GICs, skip over SGIs.
 		 * For secondary GICs, skip over PPIs, too.
@@ -1098,7 +1107,7 @@ static void __init __gic_init_bases(unsigned int gic_nr, int irq_start,
 			irq_base = irq_start;
 		}
 
-		gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
+		gic->domain = irq_domain_add_legacy(NULL, gic_irqs, irq_base,
 					hwirq_base, &gic_irq_domain_ops, gic);
 	}
 
@@ -1206,7 +1215,8 @@ gic_of_init(struct device_node *node, struct device_node *parent)
 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
 		percpu_offset = 0;
 
-	__gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
+	__gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset,
+			 &node->fwnode);
 	if (!gic_cnt)
 		gic_init_physaddr(node);
 
@@ -1281,6 +1291,7 @@ int __init
 gic_v2_acpi_init(struct acpi_table_header *table)
 {
 	void __iomem *cpu_base, *dist_base;
+	struct fwnode_handle *domain_handle;
 	int count;
 
 	/* Collect CPU base addresses */
@@ -1331,14 +1342,19 @@ gic_v2_acpi_init(struct acpi_table_header *table)
 		static_key_slow_dec(&supports_deactivate);
 
 	/*
-	 * Initialize zero GIC instance (no multi-GIC support). Also, set GIC
-	 * as default IRQ domain to allow for GSI registration and GSI to IRQ
-	 * number translation (see acpi_register_gsi() and acpi_gsi_to_irq()).
+	 * Initialize GIC instance zero (no multi-GIC support).
 	 */
-	__gic_init_bases(0, -1, dist_base, cpu_base, 0, NULL);
-	irq_set_default_host(gic_data[0].domain);
+	domain_handle = irq_domain_alloc_fwnode(dist_base);
+	if (!domain_handle) {
+		pr_err("Unable to allocate domain handle\n");
+		iounmap(cpu_base);
+		iounmap(dist_base);
+		return -ENOMEM;
+	}
+
+	__gic_init_bases(0, -1, dist_base, cpu_base, 0, domain_handle);
 
-	acpi_irq_model = ACPI_IRQ_MODEL_GIC;
+	acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, domain_handle);
 	return 0;
 }
 #endif