u-boot/arch/x86/cpu/intel_common/cpu.c

/*
 * Copyright (c) 2016 Google, Inc
 *
 * SPDX-License-Identifier:	GPL-2.0
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <asm/cpu_common.h>
#include <asm/intel_regs.h>
#include <asm/lapic.h>
#include <asm/lpc_common.h>
#include <asm/msr.h>
#include <asm/mtrr.h>
#include <asm/post.h>
#include <asm/microcode.h>

DECLARE_GLOBAL_DATA_PTR;

static int report_bist_failure(void)
{
	if (gd->arch.bist != 0) {
		post_code(POST_BIST_FAILURE);
		printf("BIST failed: %08x\n", gd->arch.bist);
		return -EFAULT;
	}

	return 0;
}

int cpu_common_init(void)
{
	struct udevice *dev, *lpc;
	int ret;

	/* Halt if there was a built in self test failure */
	ret = report_bist_failure();
	if (ret)
		return ret;

	enable_lapic();

	ret = microcode_update_intel();
	if (ret && ret != -EEXIST)
		return ret;

	/* Enable upper 128bytes of CMOS */
	writel(1 << 2, RCB_REG(RC));

	/* Early chipset init required before RAM init can work */
	uclass_first_device(UCLASS_NORTHBRIDGE, &dev);

	ret = uclass_first_device(UCLASS_LPC, &lpc);
	if (ret)
		return ret;
	if (!lpc)
		return -ENODEV;

	/* Cause the SATA device to do its early init */
	uclass_first_device(UCLASS_DISK, &dev);

	return 0;
}

int cpu_set_flex_ratio_to_tdp_nominal(void)
{
	msr_t flex_ratio, msr;
	u8 nominal_ratio;

	/* Check for Flex Ratio support */
	flex_ratio = msr_read(MSR_FLEX_RATIO);
	if (!(flex_ratio.lo & FLEX_RATIO_EN))
		return -EINVAL;

	/* Check for >0 configurable TDPs */
	msr = msr_read(MSR_PLATFORM_INFO);
	if (((msr.hi >> 1) & 3) == 0)
		return -EINVAL;

	/* Use nominal TDP ratio for flex ratio */
	msr = msr_read(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 0;

	/* Set flex ratio to nominal TDP ratio */
	flex_ratio.lo &= ~0xff00;
	flex_ratio.lo |= nominal_ratio << 8;
	flex_ratio.lo |= FLEX_RATIO_LOCK;
	msr_write(MSR_FLEX_RATIO, flex_ratio);

	/* Set flex ratio in soft reset data register bits 11:6 */
	clrsetbits_le32(RCB_REG(SOFT_RESET_DATA), 0x3f << 6,
			(nominal_ratio & 0x3f) << 6);

	debug("CPU: Soft reset to set up flex ratio\n");

	/* Set soft reset control to use register value */
	setbits_le32(RCB_REG(SOFT_RESET_CTRL), 1);

	/* Issue warm reset, will be "CPU only" due to soft reset data */
	outb(0x0, PORT_RESET);
	outb(SYS_RST | RST_CPU, PORT_RESET);
	cpu_hlt();

	/* Not reached */
	return -EINVAL;
}