drm/radeon: fix ioremap conflict with AGP mappings

this solves a regression from
http://bugzilla.kernel.org/show_bug.cgi?id=12441

Reported-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_memory.c

@@ -171,9 +171,14 @@ EXPORT_SYMBOL(drm_core_ioremap);
 
 void drm_core_ioremap_wc(struct drm_map *map, struct drm_device *dev)
 {
-	map->handle = ioremap_wc(map->offset, map->size);
+	if (drm_core_has_AGP(dev) &&
+	    dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
+		map->handle = agp_remap(map->offset, map->size, dev);
+	else
+		map->handle = ioremap_wc(map->offset, map->size);
 }
 EXPORT_SYMBOL(drm_core_ioremap_wc);
+
 void drm_core_ioremapfree(struct drm_map *map, struct drm_device *dev)
 {
 	if (!map->handle || !map->size)

drivers/gpu/drm/radeon/radeon_cp.c

@@ -1039,9 +1039,9 @@ static int radeon_do_init_cp(struct drm_device *dev, drm_radeon_init_t *init,
 
 #if __OS_HAS_AGP
 	if (dev_priv->flags & RADEON_IS_AGP) {
-		drm_core_ioremap(dev_priv->cp_ring, dev);
-		drm_core_ioremap(dev_priv->ring_rptr, dev);
-		drm_core_ioremap(dev->agp_buffer_map, dev);
+		drm_core_ioremap_wc(dev_priv->cp_ring, dev);
+		drm_core_ioremap_wc(dev_priv->ring_rptr, dev);
+		drm_core_ioremap_wc(dev->agp_buffer_map, dev);
 		if (!dev_priv->cp_ring->handle ||
 		    !dev_priv->ring_rptr->handle ||
 		    !dev->agp_buffer_map->handle) {