From: Amit Daniel Kachhap <redacted>

This patch introduces a new API for acpi based irq mapping.

[hanjun: Rework this patch to delete the reference to
gic_irq_domain_xlate() which can simplify the code a lot.]

Signed-off-by: Amit Daniel Kachhap <redacted>
Signed-off-by: Hanjun Guo <redacted>
---
 include/linux/acpi.h   |    2 ++
 kernel/irq/irqdomain.c |   27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 1e6a0ac..edd5806 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h

@@ -141,6 +141,8 @@ int acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu);
 int acpi_unmap_lsapic(int cpu);
 #endif /* CONFIG_ACPI_HOTPLUG_CPU */

+unsigned int irq_create_acpi_mapping(irq_hw_number_t hwirq,
+                                        unsigned int type);
 int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base);
 int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base);
 void acpi_irq_stats_init(void);

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index cf68bb3..c661552 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c

@@ -501,6 +501,33 @@ unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
 }
 EXPORT_SYMBOL_GPL(irq_create_of_mapping);

+#ifdef CONFIG_ACPI
+unsigned int irq_create_acpi_mapping(irq_hw_number_t hwirq,
+                                       unsigned int type)
+{
+       struct irq_domain *domain;
+       unsigned int virq;
+
+       domain = irq_default_domain;
+       if (!domain) {
+               pr_warn("no irq domain found !\n");
+               return 0;
+       }
+
+       /* Create mapping */
+       virq = irq_create_mapping(domain, hwirq);
+       if (!virq)
+               return virq;
+
+       /* Set type if specified and different than the current one */
+       if (type != IRQ_TYPE_NONE &&
+           type != irq_get_trigger_type(virq))
+               irq_set_irq_type(virq, type);
+       return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_acpi_mapping);