mirror of
https://github.com/EnderIce2/Fennix.git
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106 lines
2.6 KiB
C++
106 lines
2.6 KiB
C++
/*
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This file is part of Fennix Kernel.
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Fennix Kernel is free software: you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation, either version 3 of
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the License, or (at your option) any later version.
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Fennix Kernel is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
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*/
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#include <time.hpp>
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#include <memory.hpp>
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#include <acpi.hpp>
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#include <debug.h>
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#include <io.h>
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#include "../../kernel.h"
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namespace Time
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{
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static inline uint64_t rdtsc()
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{
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#if defined(__amd64__) || defined(__i386__)
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unsigned int lo, hi;
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__asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi));
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return ((uint64_t)hi << 32) | lo;
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#else
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return 0;
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#endif
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}
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bool TimeStampCounter::Sleep(uint64_t Nanoseconds)
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{
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uint64_t target = this->GetNanoseconds() + Nanoseconds;
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while (this->GetNanoseconds() < target)
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CPU::Pause();
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return true;
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}
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uint64_t TimeStampCounter::GetNanoseconds()
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{
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uint64_t tsc = rdtsc();
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return (tsc * 1000000000ULL) / this->clk;
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}
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TimeStampCounter::TimeStampCounter()
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{
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bool TSCInvariant = false;
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if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_AMD) == 0)
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{
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CPU::x86::AMD::CPUID0x80000007 cpuid80000007;
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if (cpuid80000007.EDX.TscInvariant)
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TSCInvariant = true;
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}
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else if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_INTEL) == 0)
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{
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// TODO: Intel 0x80000007
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CPU::x86::AMD::CPUID0x80000007 cpuid80000007;
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if (cpuid80000007.EDX.TscInvariant)
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TSCInvariant = true;
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}
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if (!TSCInvariant)
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{
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KPrint("\x1b[33mTSC is not invariant");
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return;
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}
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const int attempts = 5;
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uint64_t ns = 10000000ULL; /* 10 ms */
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uint64_t total_clk = 0;
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uint64_t overhead = 0;
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for (int i = 0; i < attempts; ++i)
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{
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uint64_t t0 = rdtsc();
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uint64_t t1 = rdtsc();
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overhead += (t1 - t0);
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}
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overhead /= attempts;
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for (int i = 0; i < attempts; ++i)
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{
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uint64_t tsc_start = rdtsc();
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uint64_t hpet_start = TimeManager->GetTimeNs();
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while (TimeManager->GetTimeNs() - hpet_start < ns)
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CPU::Pause();
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uint64_t tsc_end = rdtsc();
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total_clk += (tsc_end - tsc_start - overhead) * 1000000000ULL / ns;
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}
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this->clk = total_clk / attempts;
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KPrint("TSC frequency: %lu MHz", this->clk / 1000000);
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this->ClassCreationTime = this->GetNanoseconds();
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fixme("tsc not working as expected");
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this->clk = 0; /* disable */
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}
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}
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