[RFC Patch Part1 V1 21/30] x86, ACPI, irq: provide basic irqdomain support

[Jiang Liu <jiang.liu@linux.intel.com>]

Enhance ACPI driver to provide basic irqdomain support for IOAPIC.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
 arch/x86/kernel/acpi/boot.c |   20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index f70f4f318316..1ee639e74d50 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -31,6 +31,7 @@
 #include <linux/module.h>
 #include <linux/dmi.h>
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/slab.h>
 #include <linux/bootmem.h>
 #include <linux/ioport.h>
@@ -331,6 +332,23 @@ static void  mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
 static int mp_register_gsi(struct device *dev, u32 gsi, int trigger,
 			   int polarity);
 
+static struct irq_domain_ops acpi_irqdomain_ops;
+
+static struct irq_domain *acpi_create_irqdomain(int idx, void *arg)
+{
+	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(idx);
+
+	/*
+	 * Statically allocate IRQ number for legacy IRQs and all pins on the
+	 * first IOAPIC.
+	 */
+	if (gsi_cfg->gsi_base < NR_IRQS_LEGACY &&
+	    ioapic_dynirq_base < gsi_cfg->gsi_end)
+		ioapic_dynirq_base = gsi_cfg->gsi_end + 1;
+
+	return mp_irqdomain_create(idx, NULL, &acpi_irqdomain_ops);
+}
+
 static int __init
 acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
 {
@@ -345,7 +363,7 @@ acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
 
 	mp_register_ioapic(ioapic->id,
 			   ioapic->address, ioapic->global_irq_base,
-			   NULL, NULL);
+			   acpi_create_irqdomain, NULL);
 
 	return 0;
 }
-- 
1.7.10.4