vgaarb: Add support for setting the default video device (v2)

The default VGA device is a somewhat fluid concept on platforms with
multiple GPUs. Add support for setting it so switching code can update
things appropriately, and make sure that the sysfs code returns the right
device if it's changed.

v2: Updated to fix builds when __ARCH_HAS_VGA_DEFAULT_DEVICE is false.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: benh@kernel.crashing.org
Cc: airlied@redhat.com
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index a55e248618cd..86c63fe45d11 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -27,6 +27,7 @@
 #include <linux/security.h>
 #include <linux/pci-aspm.h>
 #include <linux/slab.h>
+#include <linux/vgaarb.h>
 #include "pci.h"
 
 static int sysfs_initialized;   /* = 0 */
@@ -417,6 +418,10 @@ static ssize_t
 boot_vga_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
         struct pci_dev *pdev = to_pci_dev(dev);
+        struct pci_dev *vga_dev = vga_default_device();
+
+        if (vga_dev)
+                return sprintf(buf, "%u\n", (pdev == vga_dev));
 
         return sprintf(buf, "%u\n",
                 !!(pdev->resource[PCI_ROM_RESOURCE].flags &