drm: Fix support for PCI domains

(For some reason I thought that went in ages ago ...)

This fixes support for PCI domains in what should hopefully be a backward
compatible way along with a change to libdrm.

When the interface version is set to 1.4, we assume userspace understands
domains and the world is at peace. We thus pass proper domain numbers
instead of 0 to userspace.

The newer libdrm will then try 1.4 first, and fallback to 1.1, along with
ignoring domains in the later case (well, except on alpha of course)

Signed-off-by: Benjamin Herrenschmidt <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/drm_ioctl.c

···
 		if (sv->drm_di_minor >= 1) {
 			/*
 			 * Version 1.1 includes tying of DRM to specific device
+			 * Version 1.4 has proper PCI domain support
 			 */
 			retcode = drm_set_busid(dev, file_priv);
 			if (retcode)

include/drm/drmP.h

···
 	return ((dev->driver->driver_features & feature) ? 1 : 0);
 }
 
-
 static inline int drm_dev_to_irq(struct drm_device *dev)
 {
 	if (drm_core_check_feature(dev, DRIVER_USE_PLATFORM_DEVICE))
···
 		return dev->pdev->irq;
 }
 
-#ifdef __alpha__
-#define drm_get_pci_domain(dev) dev->hose->index
-#else
-#define drm_get_pci_domain(dev) 0
-#endif
+static inline int drm_get_pci_domain(struct drm_device *dev)
+{
+	if (drm_core_check_feature(dev, DRIVER_USE_PLATFORM_DEVICE))
+		return 0;
+
+#ifndef __alpha__
+	/* For historical reasons, drm_get_pci_domain() is busticated
+	 * on most archs and has to remain so for userspace interface
+	 * < 1.4, except on alpha which was right from the beginning
+	 */
+	if (dev->if_version < 0x10004)
+		return 0;
+#endif /* __alpha__ */
+
+	return pci_domain_nr(dev->pdev->bus);
+}
 
 #if __OS_HAS_AGP
 static inline int drm_core_has_AGP(struct drm_device *dev)

include/drm/drm_core.h

···
 #define CORE_DATE		"20060810"
 
 #define DRM_IF_MAJOR	1
-#define DRM_IF_MINOR	3
+#define DRM_IF_MINOR	4
 
 #define CORE_MAJOR	1
 #define CORE_MINOR	1