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>

5 files changed, 85 insertions, 5 deletions

diff --git a/drivers/sh/intc/Kconfig b/drivers/sh/intc/Kconfig
index c88cbccc62b0..a305731742a9 100644
--- a/drivers/sh/intc/Kconfig
+++ b/drivers/sh/intc/Kconfig
@@ -1,3 +1,7 @@
+config SH_INTC
+        def_bool y
+        select IRQ_DOMAIN
+
 comment "Interrupt controller options"
 
 config INTC_USERIMASK
diff --git a/drivers/sh/intc/Makefile b/drivers/sh/intc/Makefile
index 44f006d09471..54ec2a0643df 100644
--- a/drivers/sh/intc/Makefile
+++ b/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
diff --git a/drivers/sh/intc/core.c b/drivers/sh/intc/core.c
index 7e562ccb6997..2374468615ed 100644
--- a/drivers/sh/intc/core.c
+++ b/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;
                         }
diff --git a/drivers/sh/intc/internals.h b/drivers/sh/intc/internals.h
index f034a979a16f..7dff08e2a071 100644
--- a/drivers/sh/intc/internals.h
+++ b/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);
diff --git a/drivers/sh/intc/irqdomain.c b/drivers/sh/intc/irqdomain.c
new file mode 100644
index 000000000000..3968f1c3c5c3
--- /dev/null
+++ b/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);
+}