src/soc/intel/braswell/memmap.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <cbmem.h>
   4 #include <cpu/x86/smm.h>
   5 #include <soc/iosf.h>
   6
   7 static size_t smm_region_size(void)
   8 {
   9         u32 smm_size;
  10         smm_size =  iosf_bunit_read(BUNIT_SMRRH) & 0xFFFF;
  11         smm_size -= iosf_bunit_read(BUNIT_SMRRL) & 0xFFFF;
  12         smm_size = (smm_size + 1) << 20;
  13         return smm_size;
  14 }
  15
  16 void smm_region(uintptr_t *start, size_t *size)
  17 {
  18         *start = (iosf_bunit_read(BUNIT_SMRRL) & 0xFFFF) << 20;
  19         *size = smm_region_size();
  20 }
  21
  22 uintptr_t cbmem_top_chipset(void)
  23 {
  24         uintptr_t smm_base;
  25         size_t smm_size;
  26
  27         /*
  28          *     +-------------------------+  Top of RAM (aligned)
  29          *     | System Management Mode  |
  30          *     |      code and data      |  Length: CONFIG_SMM_TSEG_SIZE
  31          *     |         (TSEG)          |
  32          *     +-------------------------+  SMM base (aligned)
  33          *     |                         |
  34          *     | Chipset Reserved Memory |  Length: Multiple of CONFIG_SMM_TSEG_SIZE
  35          *     |                         |
  36          *     +-------------------------+  top_of_ram (aligned)
  37          *     |                         |
  38          *     |       CBMEM Root        |
  39          *     |                         |
  40          *     +-------------------------+
  41          *     |                         |
  42          *     |   FSP Reserved Memory   |
  43          *     |                         |
  44          *     +-------------------------+
  45          *     |                         |
  46          *     |  Various CBMEM Entries  |
  47          *     |                         |
  48          *     +-------------------------+  top_of_stack (8 byte aligned)
  49          *     |                         |
  50          *     |   stack (CBMEM Entry)   |
  51          *     |                         |
  52          *     +-------------------------+
  53         */
  54
  55         smm_region(&smm_base, &smm_size);
  56         return smm_base;
  57 }