diff --git a/src/radeon_driver.c b/src/radeon_driver.c
index 7424577..80f427f 100644
--- a/src/radeon_driver.c
+++ b/src/radeon_driver.c
@@ -1333,8 +1333,9 @@ static void RADEONInitMemoryMap(ScrnInfoPtr pScrn)
 		    aper0_base &= ~(mem_size - 1);
 
 	    if (info->ChipFamily >= CHIP_FAMILY_R600) {
-		info->mc_fb_location = (aper0_base >> 24) |
-		    (((aper0_base + mem_size - 1) & 0xff000000U) >> 8);
+		uint64_t lower = aper0_base >> 24;
+		uint64_t upper = (aper0_base + mem_size - 1) >> 8;
+		info->mc_fb_location = (lower & 0xffff) | (upper & 0xffff0000);
 		ErrorF("mc fb loc is %08x\n", (unsigned int)info->mc_fb_location);
 	    } else {
 		info->mc_fb_location = (aper0_base >> 16) |
@@ -1345,21 +1346,16 @@ static void RADEONInitMemoryMap(ScrnInfoPtr pScrn)
     if (info->ChipFamily >= CHIP_FAMILY_R600) {
 	info->fbLocation = (info->mc_fb_location & 0xffff) << 24;
     } else {
-   	info->fbLocation = (info->mc_fb_location & 0xffff) << 16;
+	info->fbLocation = (info->mc_fb_location & 0xffff) << 16;
     }
     /* Just disable the damn AGP apertures for now, it may be
      * re-enabled later by the DRM
      */
 
-    if (IS_AVIVO_VARIANT) {
-	if (info->ChipFamily >= CHIP_FAMILY_R600) {
-	    OUTREG(R600_HDP_NONSURFACE_BASE, (info->mc_fb_location << 16) & 0xff0000);
-	} else {
-	    OUTREG(AVIVO_HDP_FB_LOCATION, info->mc_fb_location);
-	}
-    	info->mc_agp_location = 0x003f0000;
-    } else
-    	info->mc_agp_location = 0xffffffc0;
+    if (IS_AVIVO_VARIANT)
+	info->mc_agp_location = 0x003f0000;
+    else
+	info->mc_agp_location = 0xffffffc0;
     xf86DrvMsg(pScrn->scrnIndex, X_INFO,
 	       "RADEONInitMemoryMap() : \n");
     xf86DrvMsg(pScrn->scrnIndex, X_INFO,