| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2014 Google Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include <arch/io.h> |
| #include <cbmem.h> |
| #include <device/pci.h> |
| #include <broadwell/pci_devs.h> |
| #include <broadwell/systemagent.h> |
| |
| static uintptr_t dpr_region_start(void) |
| { |
| /* |
| * Base of DPR is top of usable DRAM below 4GiB. The register has |
| * 1 MiB alignment and reports the TOP of the range, the base |
| * must be calculated from the size in MiB in bits 11:4. |
| */ |
| uintptr_t dpr = pci_read_config32(SA_DEV_ROOT, DPR); |
| uintptr_t tom = dpr & ~((1 << 20) - 1); |
| |
| /* Subtract DMA Protected Range size if enabled */ |
| if (dpr & DPR_EPM) |
| tom -= (dpr & DPR_SIZE_MASK) << 16; |
| |
| return tom; |
| } |
| |
| void *cbmem_top(void) |
| { |
| return (void *) dpr_region_start(); |
| } |