src/drivers/amd/agesa/s3_mtrr.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <stdint.h>
   4 #include <cbmem.h>
   5 #include <cpu/x86/msr.h>
   6 #include <cpu/x86/mtrr.h>
   7 #include <cpu/amd/mtrr.h>
   8 #include <cpu/x86/cache.h>
   9 #include <string.h>
  10 #include <northbridge/amd/agesa/agesa_helper.h>
  11
  12 /* TODO: Do we want MTRR_DEF_TYPE_MSR too? */
  13 static const uint32_t msr_backup[] = {
  14         MTRR_FIX_64K_00000,
  15         MTRR_FIX_16K_80000,
  16         MTRR_FIX_16K_A0000,
  17         MTRR_FIX_4K_C0000,
  18         MTRR_FIX_4K_C8000,
  19         MTRR_FIX_4K_D0000,
  20         MTRR_FIX_4K_D8000,
  21         MTRR_FIX_4K_E0000,
  22         MTRR_FIX_4K_E8000,
  23         MTRR_FIX_4K_F0000,
  24         MTRR_FIX_4K_F8000,
  25         MTRR_PHYS_BASE(0),
  26         MTRR_PHYS_MASK(0),
  27         MTRR_PHYS_BASE(1),
  28         MTRR_PHYS_MASK(1),
  29         MTRR_PHYS_BASE(2),
  30         MTRR_PHYS_MASK(2),
  31         MTRR_PHYS_BASE(3),
  32         MTRR_PHYS_MASK(3),
  33         MTRR_PHYS_BASE(4),
  34         MTRR_PHYS_MASK(4),
  35         MTRR_PHYS_BASE(5),
  36         MTRR_PHYS_MASK(5),
  37         MTRR_PHYS_BASE(6),
  38         MTRR_PHYS_MASK(6),
  39         MTRR_PHYS_BASE(7),
  40         MTRR_PHYS_MASK(7),
  41         SYSCFG_MSR,
  42         TOP_MEM,
  43         TOP_MEM2,
  44 };
  45
  46 void backup_mtrr(void)
  47 {
  48         msr_t syscfg_msr;
  49         msr_t *mtrr_save = (msr_t *)cbmem_add(CBMEM_ID_AGESA_MTRR,
  50                                               sizeof(msr_t) * ARRAY_SIZE(msr_backup));
  51         if (!mtrr_save)
  52                 return;
  53
  54         /* Enable access to AMD RdDram and WrDram extension bits */
  55         syscfg_msr = rdmsr(SYSCFG_MSR);
  56         syscfg_msr.lo |= SYSCFG_MSR_MtrrFixDramModEn;
  57         wrmsr(SYSCFG_MSR, syscfg_msr);
  58
  59         for (int i = 0; i < ARRAY_SIZE(msr_backup); i++)
  60                 *mtrr_save++ = rdmsr(msr_backup[i]);
  61
  62         /* Disable access to AMD RdDram and WrDram extension bits */
  63         syscfg_msr = rdmsr(SYSCFG_MSR);
  64         syscfg_msr.lo &= ~SYSCFG_MSR_MtrrFixDramModEn;
  65         wrmsr(SYSCFG_MSR, syscfg_msr);
  66 }
  67
  68 void restore_mtrr(void)
  69 {
  70         msr_t syscfg_msr;
  71         msr_t *mtrr_save = (msr_t *)cbmem_find(CBMEM_ID_AGESA_MTRR);
  72
  73         if (!mtrr_save)
  74                 return;
  75
  76         /* Enable access to AMD RdDram and WrDram extension bits */
  77         syscfg_msr = rdmsr(SYSCFG_MSR);
  78         syscfg_msr.lo |= SYSCFG_MSR_MtrrFixDramModEn;
  79         wrmsr(SYSCFG_MSR, syscfg_msr);
  80
  81         for (int i = 0; i < ARRAY_SIZE(msr_backup); i++)
  82                 wrmsr(msr_backup[i], *mtrr_save++);
  83
  84         /* Disable access to AMD RdDram and WrDram extension bits */
  85         syscfg_msr = rdmsr(SYSCFG_MSR);
  86         syscfg_msr.lo &= ~SYSCFG_MSR_MtrrFixDramModEn;
  87         wrmsr(SYSCFG_MSR, syscfg_msr);
  88 }