src/arch/x86/cbmem.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <stdlib.h>
  15 #include <cbmem.h>
  16 #include <arch/acpi.h>
  17
  18 #if IS_ENABLED(CONFIG_CBMEM_TOP_BACKUP)
  19
  20 void *cbmem_top(void)
  21 {
  22         static void *cbmem_top_backup;
  23         void *top_backup;
  24
  25         if (ENV_RAMSTAGE && cbmem_top_backup != NULL)
  26                 return cbmem_top_backup;
  27
  28         /* Top of CBMEM is at highest usable DRAM address below 4GiB. */
  29         top_backup = (void *)restore_top_of_low_cacheable();
  30
  31         if (ENV_RAMSTAGE)
  32                 cbmem_top_backup = top_backup;
  33
  34         return top_backup;
  35 }
  36
  37 #endif /* CBMEM_TOP_BACKUP */
  38
  39 /* Something went wrong, our high memory area got wiped */
  40 void cbmem_fail_resume(void)
  41 {
  42 #if !defined(__PRE_RAM__) && IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)
  43         /* ACPI resume needs to be cleared in the fail-to-recover case, but that
  44          * condition is only handled during ramstage. */
  45         acpi_fail_wakeup();
  46 #endif
  47 }