sh: intc: initial irqdomain support.

Trivial support for irq domains, using either a linear map or radix tree
depending on the vector layout.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/sh/intc/Kconfig

@@ -1,3 +1,7 @@
+config SH_INTC
+	def_bool y
+	select IRQ_DOMAIN
+
 comment "Interrupt controller options"
 
 config INTC_USERIMASK

drivers/sh/intc/Makefile

@@ -1,4 +1,4 @@
-obj-y 	:= access.o chip.o core.o handle.o virq.o
+obj-y 	:= access.o chip.o core.o handle.o irqdomain.o virq.o
 
 obj-$(CONFIG_INTC_BALANCING)		+= balancing.o
 obj-$(CONFIG_INTC_USERIMASK)		+= userimask.o

drivers/sh/intc/core.c

@@ -25,6 +25,7 @@
 #include <linux/stat.h>
 #include <linux/interrupt.h>
 #include <linux/sh_intc.h>
+#include <linux/irqdomain.h>
 #include <linux/device.h>
 #include <linux/syscore_ops.h>
 #include <linux/list.h>
@@ -310,6 +311,8 @@ int __init register_intc_controller(struct intc_desc *desc)
 
 	BUG_ON(k > 256); /* _INTC_ADDR_E() and _INTC_ADDR_D() are 8 bits */
 
+	intc_irq_domain_init(d, hw);
+
 	/* register the vectors one by one */
 	for (i = 0; i < hw->nr_vectors; i++) {
 		struct intc_vect *vect = hw->vectors + i;
@@ -319,8 +322,8 @@ int __init register_intc_controller(struct intc_desc *desc)
 		if (!vect->enum_id)
 			continue;
 
-		res = irq_alloc_desc_at(irq, numa_node_id());
-		if (res != irq && res != -EEXIST) {
+		res = irq_create_identity_mapping(d->domain, irq);
+		if (unlikely(res)) {
 			pr_err("can't get irq_desc for %d\n", irq);
 			continue;
 		}
@@ -340,8 +343,8 @@ int __init register_intc_controller(struct intc_desc *desc)
 			 * IRQ support, each vector still needs to have
 			 * its own backing irq_desc.
 			 */
-			res = irq_alloc_desc_at(irq2, numa_node_id());
-			if (res != irq2 && res != -EEXIST) {
+			res = irq_create_identity_mapping(d->domain, irq2);
+			if (unlikely(res)) {
 				pr_err("can't get irq_desc for %d\n", irq2);
 				continue;
 			}

drivers/sh/intc/internals.h

@@ -1,5 +1,6 @@
 #include <linux/sh_intc.h>
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/list.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
@@ -66,6 +67,7 @@ struct intc_desc_int {
 	unsigned int nr_sense;
 	struct intc_window *window;
 	unsigned int nr_windows;
+	struct irq_domain *domain;
 	struct irq_chip chip;
 	bool skip_suspend;
 };
@@ -187,6 +189,9 @@ unsigned long intc_get_ack_handle(unsigned int irq);
 void intc_enable_disable_enum(struct intc_desc *desc, struct intc_desc_int *d,
 			      intc_enum enum_id, int enable);
 
+/* irqdomain.c */
+void intc_irq_domain_init(struct intc_desc_int *d, struct intc_hw_desc *hw);
+
 /* virq.c */
 void intc_subgroup_init(struct intc_desc *desc, struct intc_desc_int *d);
 void intc_irq_xlate_set(unsigned int irq, intc_enum id, struct intc_desc_int *d);

drivers/sh/intc/irqdomain.c

@@ -0,0 +1,68 @@
+/*
+ * IRQ domain support for SH INTC subsystem
+ *
+ * Copyright (C) 2012  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) "intc: " fmt
+
+#include <linux/irqdomain.h>
+#include <linux/sh_intc.h>
+#include <linux/export.h>
+#include "internals.h"
+
+/**
+ * intc_irq_domain_evt_xlate() - Generic xlate for vectored IRQs.
+ *
+ * This takes care of exception vector to hwirq translation through
+ * by way of evt2irq() translation.
+ *
+ * Note: For platforms that use a flat vector space without INTEVT this
+ * basically just mimics irq_domain_xlate_onecell() by way of a nopped
+ * out evt2irq() implementation.
+ */
+static int intc_evt_xlate(struct irq_domain *d, struct device_node *ctrlr,
+			  const u32 *intspec, unsigned int intsize,
+			  unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+
+	*out_hwirq = evt2irq(intspec[0]);
+	*out_type = IRQ_TYPE_NONE;
+
+	return 0;
+}
+
+static const struct irq_domain_ops intc_evt_ops = {
+	.xlate		= intc_evt_xlate,
+};
+
+void __init intc_irq_domain_init(struct intc_desc_int *d,
+				 struct intc_hw_desc *hw)
+{
+	unsigned int irq_base, irq_end;
+
+	/*
+	 * Quick linear revmap check
+	 */
+	irq_base = evt2irq(hw->vectors[0].vect);
+	irq_end = evt2irq(hw->vectors[hw->nr_vectors - 1].vect);
+
+	/*
+	 * Linear domains have a hard-wired assertion that IRQs start at
+	 * 0 in order to make some performance optimizations. Lamely
+	 * restrict the linear case to these conditions here, taking the
+	 * tree penalty for linear cases with non-zero hwirq bases.
+	 */
+	if (irq_base == 0 && irq_end == (irq_base + hw->nr_vectors - 1))
+		d->domain = irq_domain_add_linear(NULL, hw->nr_vectors,
+						  &intc_evt_ops, NULL);
+	else
+		d->domain = irq_domain_add_tree(NULL, &intc_evt_ops, NULL);
+
+	BUG_ON(!d->domain);
+}