drm/radeon/kms: fix vram setup on rs600

also fix up rs690 mem width.

should fix fdo bug 25408

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index c97eb63..00bc71f 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -320,6 +320,12 @@
 	/* FIXME: to do or is these values sane ? */
 	rdev->mc.vram_is_ddr = true;
 	rdev->mc.vram_width = 128;
+
+	rdev->mc.real_vram_size = RREG32(RADEON_CONFIG_MEMSIZE);
+	rdev->mc.mc_vram_size = rdev->mc.real_vram_size;
+
+	rdev->mc.aper_base = drm_get_resource_start(rdev->ddev, 0);
+	rdev->mc.aper_size = drm_get_resource_len(rdev->ddev, 0);
 }
 
 void rs600_bandwidth_update(struct radeon_device *rdev)