drm/radeon/kms: vram sizing on certain r100 chips needs workaround.

If an rn50/r100/m6/m7 GPU has < 64MB RAM, i.e. 8/16/32, the
aperture used to calculate the MC_FB_LOCATION needs to be worked
out from the CONFIG_APER_SIZE register, and not the actual vram size.

TTM VRAM size was also being initialised wrong, use actual vram size
to initialise it.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/rv515.c b/drivers/gpu/drm/radeon/rv515.c
index 4fd4118..551e608 100644
--- a/drivers/gpu/drm/radeon/rv515.c
+++ b/drivers/gpu/drm/radeon/rv515.c
@@ -100,10 +100,10 @@
 		       "programming pipes. Bad things might happen.\n");
 	}
 	/* Write VRAM size in case we are limiting it */
-	WREG32(RADEON_CONFIG_MEMSIZE, rdev->mc.vram_size);
+	WREG32(RADEON_CONFIG_MEMSIZE, rdev->mc.real_vram_size);
 	tmp = REG_SET(MC_FB_START, rdev->mc.vram_location >> 16);
 	WREG32(0x134, tmp);
-	tmp = rdev->mc.vram_location + rdev->mc.vram_size - 1;
+	tmp = rdev->mc.vram_location + rdev->mc.mc_vram_size - 1;
 	tmp = REG_SET(MC_FB_TOP, tmp >> 16);
 	tmp |= REG_SET(MC_FB_START, rdev->mc.vram_location >> 16);
 	WREG32_MC(MC_FB_LOCATION, tmp);
@@ -369,10 +369,7 @@
 	fixed20_12 a;
 
 	rv515_vram_get_type(rdev);
-	rdev->mc.vram_size = RREG32(CONFIG_MEMSIZE);
 
-	rdev->mc.aper_base = drm_get_resource_start(rdev->ddev, 0);
-	rdev->mc.aper_size = drm_get_resource_len(rdev->ddev, 0);
 	/* FIXME: we should enforce default clock in case GPU is not in
 	 * default setup
 	 */