src/soc/nvidia/tegra132/cbmem.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright 2014 Google Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <cbmem.h>
  17 #include <soc/addressmap.h>
  18
  19 void *cbmem_top(void)
  20 {
  21         static uintptr_t addr;
  22
  23         if (addr == 0) {
  24                 uintptr_t begin_mib;
  25                 uintptr_t end_mib;
  26
  27                 memory_in_range_below_4gb(&begin_mib, &end_mib);
  28                 /* Make sure we consume everything up to 4GiB. */
  29                 if (end_mib == 4096)
  30                         addr = ~(uint32_t)0;
  31                 else
  32                         addr = end_mib << 20;
  33         }
  34
  35         return (void *)addr;
  36 }