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/* SPDX-License-Identifier: GPL-2.0-only */
#include <arch/cpu.h>
#include <cpu/intel/common/common.h>
#include <cpu/x86/msr.h>
#include <device/mmio.h>
#include <security/intel/txt/txt.h>
#include <security/tpm/tis.h>
#include <timer.h>
#include "txtlib.h"
#include "txt_register.h"
bool is_establishment_bit_asserted(void)
{
struct stopwatch timer;
uint8_t access;
/* Spec says no less than 30 milliseconds */
stopwatch_init_msecs_expire(&timer, 50);
while (true) {
access = read8((void *)TPM_ACCESS_REG);
/* Register returns all ones if TPM is missing */
if (access == 0xff)
return false;
if (access & TPM_ACCESS_VALID)
break;
/* On timeout, assume that the TPM is not working */
if (stopwatch_expired(&timer))
return false;
}
/* This bit uses inverted logic: if cleared, establishment is asserted */
return !(access & TPM_ACCESS_ESTABLISHMENT);
}
bool is_txt_cpu(void)
{
const uint32_t ecx = cpu_get_feature_flags_ecx();
return (ecx & (CPUID_SMX | CPUID_VMX)) == (CPUID_SMX | CPUID_VMX);
}
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