src/cpu/intel/haswell/bootblock.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <stdint.h>
   4 #include <arch/bootblock.h>
   5 #include <cpu/x86/msr.h>
   6 #include <arch/io.h>
   7 #include <delay.h>
   8 #include <halt.h>
   9
  10 #include "haswell.h"
  11
  12 #include <southbridge/intel/lynxpoint/pch.h>
  13
  14 static void set_flex_ratio_to_tdp_nominal(void)
  15 {
  16         msr_t flex_ratio, msr;
  17         u32 soft_reset;
  18         u8 nominal_ratio;
  19
  20         /* Check for Flex Ratio support */
  21         flex_ratio = rdmsr(MSR_FLEX_RATIO);
  22         if (!(flex_ratio.lo & FLEX_RATIO_EN))
  23                 return;
  24
  25         /* Check for >0 configurable TDPs */
  26         msr = rdmsr(MSR_PLATFORM_INFO);
  27         if (((msr.hi >> 1) & 3) == 0)
  28                 return;
  29
  30         /* Use nominal TDP ratio for flex ratio */
  31         msr = rdmsr(MSR_CONFIG_TDP_NOMINAL);
  32         nominal_ratio = msr.lo & 0xff;
  33
  34         /* See if flex ratio is already set to nominal TDP ratio */
  35         if (((flex_ratio.lo >> 8) & 0xff) == nominal_ratio)
  36                 return;
  37
  38         /* Set flex ratio to nominal TDP ratio */
  39         flex_ratio.lo &= ~0xff00;
  40         flex_ratio.lo |= nominal_ratio << 8;
  41         flex_ratio.lo |= FLEX_RATIO_LOCK;
  42         wrmsr(MSR_FLEX_RATIO, flex_ratio);
  43
  44         /* Set flex ratio in soft reset data register bits 11:6.
  45          * RCBA region is enabled in southbridge bootblock */
  46         soft_reset = RCBA32(SOFT_RESET_DATA);
  47         soft_reset &= ~(0x3f << 6);
  48         soft_reset |= (nominal_ratio & 0x3f) << 6;
  49         RCBA32(SOFT_RESET_DATA) = soft_reset;
  50
  51         /* Set soft reset control to use register value */
  52         RCBA32_OR(SOFT_RESET_CTRL, 1);
  53
  54         /* Delay before reset to avoid potential TPM lockout */
  55         if (CONFIG(TPM))
  56                 mdelay(30);
  57
  58         /* Issue warm reset, will be "CPU only" due to soft reset data */
  59         outb(0x0, 0xcf9);
  60         outb(0x6, 0xcf9);
  61         halt();
  62 }
  63
  64 void bootblock_early_cpu_init(void)
  65 {
  66         /* Set flex ratio and reset if needed */
  67         set_flex_ratio_to_tdp_nominal();
  68 }