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-rw-r--r--kernel/irq/Kconfig4
-rw-r--r--kernel/irq/Makefile1
-rw-r--r--kernel/irq/irqdomain.c122
3 files changed, 127 insertions, 0 deletions
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index d1d051b38e0b..5a38bf4de641 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -52,6 +52,10 @@ config IRQ_EDGE_EOI_HANDLER
config GENERIC_IRQ_CHIP
bool
+# Generic irq_domain hw <--> linux irq number translation
+config IRQ_DOMAIN
+ bool
+
# Support forced irq threading
config IRQ_FORCED_THREADING
bool
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 73290056cfb6..fff17381f0af 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -2,6 +2,7 @@
obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o
obj-$(CONFIG_GENERIC_IRQ_CHIP) += generic-chip.o
obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
+obj-$(CONFIG_IRQ_DOMAIN) += irqdomain.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
obj-$(CONFIG_PM_SLEEP) += pm.o
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
new file mode 100644
index 000000000000..29c7bd42e25d
--- /dev/null
+++ b/kernel/irq/irqdomain.c
@@ -0,0 +1,122 @@
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+
+static LIST_HEAD(irq_domain_list);
+static DEFINE_MUTEX(irq_domain_mutex);
+
+/**
+ * irq_domain_add() - Register an irq_domain
+ * @domain: ptr to initialized irq_domain structure
+ *
+ * Registers an irq_domain structure. The irq_domain must at a minimum be
+ * initialized with an ops structure pointer, and either a ->to_irq hook or
+ * a valid irq_base value. Everything else is optional.
+ */
+void irq_domain_add(struct irq_domain *domain)
+{
+ struct irq_data *d;
+ int hwirq;
+
+ /*
+ * This assumes that the irq_domain owner has already allocated
+ * the irq_descs. This block will be removed when support for dynamic
+ * allocation of irq_descs is added to irq_domain.
+ */
+ for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
+ d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
+ if (d || d->domain) {
+ /* things are broken; just report, don't clean up */
+ WARN(1, "error: irq_desc already assigned to a domain");
+ return;
+ }
+ d->domain = domain;
+ d->hwirq = hwirq;
+ }
+
+ mutex_lock(&irq_domain_mutex);
+ list_add(&domain->list, &irq_domain_list);
+ mutex_unlock(&irq_domain_mutex);
+}
+
+/**
+ * irq_domain_del() - Unregister an irq_domain
+ * @domain: ptr to registered irq_domain.
+ */
+void irq_domain_del(struct irq_domain *domain)
+{
+ struct irq_data *d;
+ int hwirq;
+
+ mutex_lock(&irq_domain_mutex);
+ list_del(&domain->list);
+ mutex_unlock(&irq_domain_mutex);
+
+ /* Clear the irq_domain assignments */
+ for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
+ d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
+ d->domain = NULL;
+ }
+}
+
+#if defined(CONFIG_OF_IRQ)
+/**
+ * irq_create_of_mapping() - Map a linux irq number from a DT interrupt spec
+ *
+ * Used by the device tree interrupt mapping code to translate a device tree
+ * interrupt specifier to a valid linux irq number. Returns either a valid
+ * linux IRQ number or 0.
+ *
+ * When the caller no longer need the irq number returned by this function it
+ * should arrange to call irq_dispose_mapping().
+ */
+unsigned int irq_create_of_mapping(struct device_node *controller,
+ const u32 *intspec, unsigned int intsize)
+{
+ struct irq_domain *domain;
+ unsigned long hwirq;
+ unsigned int irq, type;
+ int rc = -EINVAL;
+
+ /* Find a domain which can translate the irq spec */
+ mutex_lock(&irq_domain_mutex);
+ list_for_each_entry(domain, &irq_domain_list, list) {
+ if (!domain->ops->dt_translate)
+ continue;
+ rc = domain->ops->dt_translate(domain, controller,
+ intspec, intsize, &hwirq, &type);
+ if (rc == 0)
+ break;
+ }
+ mutex_unlock(&irq_domain_mutex);
+
+ if (rc != 0)
+ return 0;
+
+ irq = irq_domain_to_irq(domain, hwirq);
+ if (type != IRQ_TYPE_NONE)
+ irq_set_irq_type(irq, type);
+ pr_debug("%s: mapped hwirq=%i to irq=%i, flags=%x\n",
+ controller->full_name, (int)hwirq, irq, type);
+ return irq;
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+/**
+ * irq_dispose_mapping() - Discard a mapping created by irq_create_of_mapping()
+ * @irq: linux irq number to be discarded
+ *
+ * Calling this function indicates the caller no longer needs a reference to
+ * the linux irq number returned by a prior call to irq_create_of_mapping().
+ */
+void irq_dispose_mapping(unsigned int irq)
+{
+ /*
+ * nothing yet; will be filled when support for dynamic allocation of
+ * irq_descs is added to irq_domain
+ */
+}
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
+#endif /* CONFIG_OF_IRQ */