blob: 51244b83aeeebad87dc4691b10f4365383fb2da8 [file] [log] [blame]
/*
* This file is part of the coreboot project.
*
* 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; version 2 of the License.
*
* 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 <stdint.h>
#include <arch/cpu.h>
#include <cpu/x86/msr.h>
#include <cpu/amd/msr.h>
#include <timer.h>
#include <device/pci.h>
#include <device/pci_ops.h>
#include <northbridge/amd/amdht/AsPsDefs.h>
static struct monotonic_counter {
int initialized;
uint32_t core_frequency;
struct mono_time time;
uint64_t last_value;
} mono_counter;
static inline uint64_t read_counter_msr(void)
{
msr_t counter_msr;
counter_msr = rdmsr(TSC_MSR);
return ((uint64_t)counter_msr.hi << 32) | (uint64_t)counter_msr.lo;
}
static void init_timer(void)
{
uint8_t model;
uint32_t cpuid_fms;
uint8_t cpufid;
uint8_t cpudid;
uint8_t boost_capable = 0;
/* Get CPU model */
cpuid_fms = cpuid_eax(0x80000001);
model = ((cpuid_fms & 0xf0000) >> 16) | ((cpuid_fms & 0xf0) >> 4);
/* Get boost capability */
if ((model == 0x8) || (model == 0x9)) { /* revision D */
boost_capable = (pci_read_config32(pcidev_on_root(0x18, 4),
0x15c) & 0x4) >> 2;
}
/* Set up TSC (BKDG v3.62 section 2.9.4)*/
msr_t msr = rdmsr(HWCR_MSR);
msr.lo |= 0x1000000;
wrmsr(HWCR_MSR, msr);
/* Get core Pstate 0 frequency in MHz */
msr = rdmsr(PSTATE_0_MSR + boost_capable);
cpufid = (msr.lo & 0x3f);
cpudid = (msr.lo & 0x1c0) >> 6;
mono_counter.core_frequency = (100 * (cpufid + 0x10)) / (0x01 << cpudid);
mono_counter.last_value = read_counter_msr();
mono_counter.initialized = 1;
}
void timer_monotonic_get(struct mono_time *mt)
{
uint64_t current_tick;
uint32_t usecs_elapsed = 0;
if (!mono_counter.initialized)
init_timer();
current_tick = read_counter_msr();
if (mono_counter.core_frequency != 0)
usecs_elapsed = (current_tick - mono_counter.last_value) / mono_counter.core_frequency;
/* Update current time and tick values only if a full tick occurred. */
if (usecs_elapsed) {
mono_time_add_usecs(&mono_counter.time, usecs_elapsed);
mono_counter.last_value = current_tick;
}
/* Save result. */
*mt = mono_counter.time;
}