ACPI/PCI: call _OSC support during root bridge discovery

Add pci_acpi_osc_support() and call it when a PCI bridge is added.  This
allows us to avoid having every individual PCI root bridge driver call
_OSC support for every root bridge in their probe functions, a
significant savings in boot time.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 642554b1b60..de4d57114fe 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -31,6 +31,7 @@
 #include <linux/spinlock.h>
 #include <linux/pm.h>
 #include <linux/pci.h>
+#include <linux/pci-acpi.h>
 #include <linux/acpi.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
@@ -193,6 +194,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
         unsigned long long value = 0;
         acpi_handle handle = NULL;
         struct acpi_device *child;
+        u32 flags;
 
 
         if (!device)
@@ -210,6 +212,13 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 
         device->ops.bind = acpi_pci_bind;
 
+        /*
+         * All supported architectures that use ACPI have support for
+         * PCI domains, so we indicate this in _OSC support capabilities.
+         */
+        flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
+        pci_acpi_osc_support(device->handle, flags);
+
         /* 
          * Segment
          * -------