bootblock.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <stdint.h>
#include <arch/bootblock.h>
#include <arch/cpu.h>
#include <cpu/x86/msr.h>
#include <arch/io.h>
#include <halt.h>
 
#include "model_206ax.h"
 
#if CONFIG(SOUTHBRIDGE_INTEL_BD82X6X) || \
        CONFIG(SOUTHBRIDGE_INTEL_C216)
/* Needed for RCBA access to set Soft Reset Data register */
#include <southbridge/intel/bd82x6x/pch.h>
#else
#error "CPU must be paired with Intel BD82X6X or C216 southbridge"
#endif
 
static void set_flex_ratio_to_tdp_nominal(void)
{
        msr_t flex_ratio, msr;
        u32 soft_reset;
        u8 nominal_ratio;
 
        /* Minimum CPU revision for configurable TDP support */
        if (cpuid_eax(1) < IVB_CONFIG_TDP_MIN_CPUID)
                return;
 
        /* Check for Flex Ratio support */
        flex_ratio = rdmsr(MSR_FLEX_RATIO);
        if (!(flex_ratio.lo & FLEX_RATIO_EN))
                return;
 
        /* Check for >0 configurable TDPs */
        msr = rdmsr(MSR_PLATFORM_INFO);
        if (((msr.hi >> 1) & 3) == 0)
                return;
 
        /* Use nominal TDP ratio for flex ratio */
        msr = rdmsr(MSR_CONFIG_TDP_NOMINAL);
        nominal_ratio = msr.lo & 0xff;
 
        /* See if flex ratio is already set to nominal TDP ratio */
        if (((flex_ratio.lo >> 8) & 0xff) == nominal_ratio)
                return;
 
        /* Set flex ratio to nominal TDP ratio */
        flex_ratio.lo &= ~0xff00;
        flex_ratio.lo |= nominal_ratio << 8;
        flex_ratio.lo |= FLEX_RATIO_LOCK;
        wrmsr(MSR_FLEX_RATIO, flex_ratio);
 
        /* Set flex ratio in soft reset data register bits 11:6.
         * RCBA region is enabled in southbridge bootblock */
        soft_reset = RCBA32(SOFT_RESET_DATA);
        soft_reset &= ~(0x3f << 6);
        soft_reset |= (nominal_ratio & 0x3f) << 6;
        RCBA32(SOFT_RESET_DATA) = soft_reset;
 
        /* Set soft reset control to use register value */
        RCBA32_OR(SOFT_RESET_CTRL, 1);
 
        /* Issue warm reset, will be "CPU only" due to soft reset data */
        outb(0x0, 0xcf9);
        outb(0x6, 0xcf9);
        halt();
}
 
void bootblock_early_cpu_init(void)
{
        /* Set flex ratio and reset if needed */
        set_flex_ratio_to_tdp_nominal();
}