memtest86plus/system/timers.c
Chao Li 3ce7c3fb39
loongarch: Add 64-bit PCIe memory space mapping and change the stable timer as the main timer (#450)
* system/loongarch: Add 64-bit PCIe memory space mapping

Added the 64-bit PCIe memory space mapping. From 0x8000000000ULL to
0xFD00000000ULL are LoongArch 64-bit PCIe memory spaces and need to be
mapped.

Signed-off-by: Chao Li <lichao@loongson.cn>

* system/loongarch: Optimization timer on LoongArch

Since some LoongArch64 CPUs stop the performance counters when ilde, the
running time displayed on the screen is incorrect.

Using stable counter can solve this problem, so remove the performance
counters time, and add stable counter time.

Signed-off-by: Chao Li <lichao@loongson.cn>

---------

Signed-off-by: Chao Li <lichao@loongson.cn>
2024-10-24 19:28:00 +02:00

142 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2020-2022 Martin Whitaker.
// Copyright (C) 2004-2022 Sam Demeulemeester.
// Copyright (C) 2024 Loongson Technology Corporation Limited. All rights reserved.
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "acpi.h"
#include "cpuid.h"
#include "cpuinfo.h"
#include "io.h"
#include "tsc.h"
#if defined(__loongarch_lp64)
// LoongArch GCC builtin function
#include <larchintrin.h>
#include "registers.h"
#endif
//------------------------------------------------------------------------------
// Constants
//------------------------------------------------------------------------------
#define PIT_TICKS_50mS 59659 // PIT clock is 1.193182MHz
#define APIC_TICKS_50mS 178977 // APIC clock is 3.579545MHz
//------------------------------------------------------------------------------
// Private Functions
//------------------------------------------------------------------------------
#if defined(__i386__) || defined(__x86_64__)
static void correct_tsc(void)
{
uint32_t start_time, end_time, run_time, counter;
int loops = 0;
if (cpuid_info.flags.rdtsc == 0) {
return;
}
// If available, use APIC Timer to find TSC correction factor
if (acpi_config.pm_is_io && acpi_config.pm_addr != 0) {
rdtscl(start_time);
counter = inl(acpi_config.pm_addr);
// Generate a dirty delay
for(volatile uint8_t i=0; i<100u; i++);
// Make sure counter is incrementing
if (inl(acpi_config.pm_addr) > counter) {
while (1) {
if (inl(acpi_config.pm_addr) > (counter + APIC_TICKS_50mS) || loops > 1000000) {
break;
}
loops++;
}
rdtscl(end_time);
run_time = end_time - start_time;
// Make sure we have a credible result
if (loops >= 10 && run_time >= 50000) {
clks_per_msec = run_time / 50;
return;
}
}
}
// Use PIT Timer to find TSC correction factor if APIC not available
outb((inb(0x61) & ~0x02) | 0x01, 0x61);
outb(0xb0, 0x43);
outb(PIT_TICKS_50mS & 0xff, 0x42);
outb(PIT_TICKS_50mS >> 8, 0x42);
rdtscl(start_time);
loops = 0;
do {
loops++;
} while ((inb(0x61) & 0x20) == 0);
rdtscl(end_time);
run_time = end_time - start_time;
// Make sure we have a credible result
if (loops >= 4 && run_time >= 50000) {
clks_per_msec = run_time / 50;
}
}
#elif defined(__loongarch_lp64)
static void correct_tsc(void)
{
uint64_t start, end, excepted_ticks, current_ticks, calc_base_freq, clock_multiplier, clock_divide;
uint64_t num_millisec = 50, millisec_div = 1000;
//
// Enable PMCNT0.
//
__csrxchg_d((0x1 << 16), (0x1 << 16) | 0x3FF, LOONGARCH_CSR_PERFCTRL0);
//
// Get stable count frequency
//
calc_base_freq = __cpucfg(0x4);
clock_multiplier = __cpucfg(0x5) & 0xFFFF;
clock_divide = (__cpucfg(0x5) >> 16) & 0xFFFF;
excepted_ticks = (((calc_base_freq * clock_multiplier) / clock_divide) * num_millisec) / millisec_div;
__asm__ __volatile__("rdtime.d %0, $zero":"=r"(current_ticks):);
excepted_ticks += current_ticks;
start = __csrrd_d(LOONGARCH_CSR_PERFCNTR0);
do {
__asm__ __volatile__("rdtime.d %0, $zero":"=r"(current_ticks):);
} while (current_ticks < excepted_ticks);
end = __csrrd_d(LOONGARCH_CSR_PERFCNTR0);
//
// Disable PMCNT0.
//
__csrxchg_d(0, (0x1 << 16) | 0x3FF, LOONGARCH_CSR_PERFCTRL0);
clks_per_msec = (end - start) / num_millisec;
}
#endif
//------------------------------------------------------------------------------
// Public Functions
//------------------------------------------------------------------------------
void timers_init(void)
{
correct_tsc();
}