ACPI: Altix: ACPI _PRT support

Provide ACPI _PRT support for SN Altix systems.

The SN Altix platform does not conform to the
IOSAPIC IRQ routing model, so a new acpi_irq_model
(ACPI_IRQ_MODEL_PLATFORM) has been defined. The SN
platform specific code sets acpi_irq_model to
this new value, and keys off of it in acpi_register_gsi()
to avoid the iosapic code path.

Signed-off-by: John Keller <jpk@sgi.com>
Signed-off-by: Len Brown <len.brown@intel.com>

4 files changed, 10 insertions, 0 deletions

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 73ef4a85b861..ef2fe474f107 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -590,6 +590,9 @@ void __init acpi_numa_arch_fixup(void)
  */
 int acpi_register_gsi(u32 gsi, int triggering, int polarity)
 {
+        if (acpi_irq_model == ACPI_IRQ_MODEL_PLATFORM)
+                return gsi;
+
         if (has_8259 && gsi < 16)
                 return isa_irq_to_vector(gsi);
 
diff --git a/arch/ia64/sn/kernel/io_acpi_init.c b/arch/ia64/sn/kernel/io_acpi_init.c
index 99d7f278612a..cb96b4ea7df6 100644
--- a/arch/ia64/sn/kernel/io_acpi_init.c
+++ b/arch/ia64/sn/kernel/io_acpi_init.c
@@ -223,6 +223,9 @@ sn_io_acpi_init(void)
         u64 result;
         s64 status;
 
+        /* SN Altix does not follow the IOSAPIC IRQ routing model */
+        acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
+
         acpi_bus_register_driver(&acpi_sn_hubdev_driver);
         status = sal_ioif_init(&result);
         if (status || result)
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 279c4bac92e5..766332e45592 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -561,6 +561,9 @@ static int __init acpi_bus_init_irq(void)
         case ACPI_IRQ_MODEL_IOSAPIC:
                 message = "IOSAPIC";
                 break;
+        case ACPI_IRQ_MODEL_PLATFORM:
+                message = "platform specific model";
+                break;
         default:
                 printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
                 return -ENODEV;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 2b0c955590fe..91f1f2363870 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -47,6 +47,7 @@ enum acpi_irq_model_id {
         ACPI_IRQ_MODEL_PIC = 0,
         ACPI_IRQ_MODEL_IOAPIC,
         ACPI_IRQ_MODEL_IOSAPIC,
+        ACPI_IRQ_MODEL_PLATFORM,
         ACPI_IRQ_MODEL_COUNT
 };