refactor(kernel): ♻️ rewrite time manager

2025-07-02 19:09:16 +00:00 · 2025-05-23 23:30:04 +00:00
parent 9538589c11
commit 33c284091d
31 changed files with 572 additions and 573 deletions
--- a/Kernel/subsystem/time/tsc.cpp
+++ b/Kernel/subsystem/time/tsc.cpp
@ -0,0 +1,105 @@
+/*
+	This file is part of Fennix Kernel.
+
+	Fennix Kernel 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 3 of
+	the License, or (at your option) any later version.
+
+	Fennix Kernel 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.
+
+	You should have received a copy of the GNU General Public License
+	along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <time.hpp>
+
+#include <memory.hpp>
+#include <acpi.hpp>
+#include <debug.h>
+#include <io.h>
+
+#include "../../kernel.h"
+
+namespace Time
+{
+	static inline uint64_t rdtsc()
+	{
+#if defined(__amd64__) || defined(__i386__)
+		unsigned int lo, hi;
+		__asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi));
+		return ((uint64_t)hi << 32) | lo;
+#else
+		return 0;
+#endif
+	}
+
+	bool TimeStampCounter::Sleep(uint64_t Nanoseconds)
+	{
+		uint64_t target = this->GetNanoseconds() + Nanoseconds;
+		while (this->GetNanoseconds() < target)
+			CPU::Pause();
+		return true;
+	}
+
+	uint64_t TimeStampCounter::GetNanoseconds()
+	{
+		uint64_t tsc = rdtsc();
+		return (tsc * 1000000000ULL) / this->clk;
+	}
+
+	TimeStampCounter::TimeStampCounter()
+	{
+		bool TSCInvariant = false;
+		if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_AMD) == 0)
+		{
+			CPU::x86::AMD::CPUID0x80000007 cpuid80000007;
+			if (cpuid80000007.EDX.TscInvariant)
+				TSCInvariant = true;
+		}
+		else if (strcmp(CPU::Vendor(), x86_CPUID_VENDOR_INTEL) == 0)
+		{
+			// TODO: Intel 0x80000007
+			CPU::x86::AMD::CPUID0x80000007 cpuid80000007;
+			if (cpuid80000007.EDX.TscInvariant)
+				TSCInvariant = true;
+		}
+
+		if (!TSCInvariant)
+		{
+			KPrint("\x1b[33mTSC is not invariant");
+			return;
+		}
+
+		const int attempts = 5;
+		uint64_t ns = 10000000ULL; /* 10 ms */
+		uint64_t total_clk = 0;
+		uint64_t overhead = 0;
+
+		for (int i = 0; i < attempts; ++i)
+		{
+			uint64_t t0 = rdtsc();
+			uint64_t t1 = rdtsc();
+			overhead += (t1 - t0);
+		}
+		overhead /= attempts;
+
+		for (int i = 0; i < attempts; ++i)
+		{
+			uint64_t tsc_start = rdtsc();
+			uint64_t hpet_start = TimeManager->GetTimeNs();
+			while (TimeManager->GetTimeNs() - hpet_start < ns)
+				CPU::Pause();
+			uint64_t tsc_end = rdtsc();
+			total_clk += (tsc_end - tsc_start - overhead) * 1000000000ULL / ns;
+		}
+		this->clk = total_clk / attempts;
+		KPrint("TSC frequency: %lu MHz", this->clk / 1000000);
+		this->ClassCreationTime = this->GetNanoseconds();
+		fixme("tsc not working as expected");
+		this->clk = 0; /* disable */
+	}
+}