blob: 8c1888400173fab890ca4bdc5618ba10f1b3c6fd [file] [log] [blame]
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2015 Intel Corp.
* Copyright (C) 2017 Advanced Micro Devices
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <arch/io.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/tsc.h>
#include <cpu/amd/amdfam15.h>
#include <console/console.h>
#include <soc/pci_devs.h>
#include <device/pci_ops.h>
unsigned long tsc_freq_mhz(void)
{
msr_t msr;
uint8_t cpufid;
uint8_t cpudid;
uint8_t boost_states;
/*
* See the Family 15h Models 70h-7Fh BKDG (PID 55072) definition for
* MSR0000_0010. The TSC increments at the P0 frequency. According
* to the "Software P-state Numbering" section, P0 is the highest
* non-boosted state. freq = 100MHz * (CpuFid + 10h) / (2^(CpuDid)).
*/
boost_states = (pci_read_config32(DEV_D18F4, CORE_PERF_BOOST_CTRL)
>> 2) & 0x7;
msr = rdmsr(PSTATE_0_MSR + boost_states);
if (!(msr.hi & 0x80000000))
die("Unknown error: cannot determine P-state 0\n");
cpufid = (msr.lo & 0x3f);
cpudid = (msr.lo & 0x1c0) >> 6;
return (100 * (cpufid + 0x10)) / (0x01 << cpudid);
}