Ignore RAMTOP for MTRRs

Without RELOCATABLE_RAMSTAGE have WB cache large enough
to cover the greatest ramstage needs, as there is no benefit
of trying to accurately match the actual need. Choose
this to be bottom 16MiB.

With RELOCATABLE_RAMSTAGE write-back cache of low ram is
only useful for bottom 1MiB of RAM as a small part of this gets used
during SMP initialisation before proper MTRR setup.

Change-Id: Icd5f8461f81ed0e671130f1142641a48d1304f30
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/15249
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/cpu/intel/haswell/romstage.c b/src/cpu/intel/haswell/romstage.c
index b8ce5d6..0e8fd09 100644
--- a/src/cpu/intel/haswell/romstage.c
+++ b/src/cpu/intel/haswell/romstage.c
@@ -119,9 +119,9 @@
 	slot = stack_push(slot, ~(CACHE_ROM_SIZE - 1) | MTRR_TYPE_WRPROT);
 	num_mtrrs++;
 
-	/* Cache RAM as WB from 0 -> CONFIG_RAMTOP. */
+	/* Cache RAM as WB from 0 -> CACHE_TMP_RAMTOP. */
 	slot = stack_push(slot, mtrr_mask_upper); /* upper mask */
-	slot = stack_push(slot, ~(CONFIG_RAMTOP - 1) | MTRR_PHYS_MASK_VALID);
+	slot = stack_push(slot, ~(CACHE_TMP_RAMTOP - 1) | MTRR_PHYS_MASK_VALID);
 	slot = stack_push(slot, 0); /* upper base */
 	slot = stack_push(slot, 0 | MTRR_TYPE_WRBACK);
 	num_mtrrs++;