x86, ACPI, irq: Provide basic irqdomain support

Enhance ACPI driver to provide basic irqdomain support for IOAPIC.

We will build identity mapping for IOAPICs hosting legacy IRQs,
otherwise dynamically allocate IRQ numbers for IOAPIC pins on demand.

Signed-off-by: Jiang Liu <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Grant Likely <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Pavel Machek <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

1 files changed, 13 insertions, 2 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index f86b4bae4640..8d9aee1e67e8 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>
@@ -449,10 +450,16 @@ static int mp_register_gsi(struct device *dev, u32 gsi, int trigger,
 	return irq;
 }
 
+static struct irq_domain_ops acpi_irqdomain_ops;
+
 static int __init
 acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
 {
 	struct acpi_madt_io_apic *ioapic = NULL;
+	struct ioapic_domain_cfg cfg = {
+		.type = IOAPIC_DOMAIN_DYNAMIC,
+		.ops = &acpi_irqdomain_ops,
+	};
 
 	ioapic = (struct acpi_madt_io_apic *)header;
 
@@ -461,8 +468,12 @@ acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
 
 	acpi_table_print_madt_entry(header);
 
-	mp_register_ioapic(ioapic->id,
-			   ioapic->address, ioapic->global_irq_base, NULL);
+	/* Statically assign IRQ numbers for IOAPICs hosting legacy IRQs */
+	if (ioapic->global_irq_base < nr_legacy_irqs())
+		cfg.type = IOAPIC_DOMAIN_LEGACY;
+
+	mp_register_ioapic(ioapic->id, ioapic->address, ioapic->global_irq_base,
+			   &cfg);
 
 	return 0;
 }