From 198e6d7cf62cf90c5d2563fa1b9db7793996ef27 Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Fri, 4 Aug 2023 10:22:20 +0300
Subject: [PATCH] Kernel: Start work on abstracting Timers

---
 kernel/CMakeLists.txt                 |  5 +--
 kernel/arch/x86_64/IDT.cpp            |  1 +
 kernel/include/kernel/Debug.h         | 16 ++++-----
 kernel/include/kernel/PIT.h           | 14 --------
 kernel/include/kernel/Timer/PIT.h     | 23 ++++++++++++
 kernel/include/kernel/Timer/Timer.h   | 36 +++++++++++++++++++
 kernel/kernel/Debug.cpp               |  6 ++++
 kernel/kernel/FS/DevFS/FileSystem.cpp |  3 +-
 kernel/kernel/Input/PS2Controller.cpp |  9 ++---
 kernel/kernel/Process.cpp             |  5 +--
 kernel/kernel/Scheduler.cpp           |  3 +-
 kernel/kernel/Storage/ATABus.cpp      |  9 ++---
 kernel/kernel/{ => Timer}/PIT.cpp     | 20 ++++++++---
 kernel/kernel/Timer/Timer.cpp         | 51 +++++++++++++++++++++++++++
 kernel/kernel/kernel.cpp              |  8 ++---
 15 files changed, 163 insertions(+), 46 deletions(-)
 delete mode 100644 kernel/include/kernel/PIT.h
 create mode 100644 kernel/include/kernel/Timer/PIT.h
 create mode 100644 kernel/include/kernel/Timer/Timer.h
 rename kernel/kernel/{ => Timer}/PIT.cpp (78%)
 create mode 100644 kernel/kernel/Timer/Timer.cpp

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index c9a69f5cec..9f0899ca1b 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -40,7 +40,6 @@ set(KERNEL_SOURCES
 	kernel/Panic.cpp
 	kernel/PCI.cpp
 	kernel/PIC.cpp
-	kernel/PIT.cpp
 	kernel/Process.cpp
 	kernel/RTC.cpp
 	kernel/Scheduler.cpp
@@ -55,9 +54,11 @@ set(KERNEL_SOURCES
 	kernel/Storage/StorageDevice.cpp
 	kernel/Syscall.cpp
 	kernel/Syscall.S
-	kernel/Thread.cpp
 	kernel/Terminal/TTY.cpp
 	kernel/Terminal/VesaTerminalDriver.cpp
+	kernel/Thread.cpp
+	kernel/Timer/PIT.cpp
+	kernel/Timer/Timer.cpp
 	icxxabi.cpp
 )
 
diff --git a/kernel/arch/x86_64/IDT.cpp b/kernel/arch/x86_64/IDT.cpp
index 0c27543907..72216b9a35 100644
--- a/kernel/arch/x86_64/IDT.cpp
+++ b/kernel/arch/x86_64/IDT.cpp
@@ -6,6 +6,7 @@
 #include <kernel/Panic.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
+#include <kernel/Timer/PIT.h>
 
 #include <unistd.h>
 
diff --git a/kernel/include/kernel/Debug.h b/kernel/include/kernel/Debug.h
index d34c0fca17..086f0f3714 100644
--- a/kernel/include/kernel/Debug.h
+++ b/kernel/include/kernel/Debug.h
@@ -1,15 +1,14 @@
 #pragma once
 
 #include <BAN/Formatter.h>
-#include <kernel/PIT.h>
 
-#define dprintln(...)																																\
-	do {																																			\
-		Debug::DebugLock::lock();																													\
-		BAN::Formatter::print(Debug::putchar, "[{5}.{3}] {}:{}:  ", PIT::ms_since_boot() / 1000, PIT::ms_since_boot() % 1000, __FILE__, __LINE__);	\
-		BAN::Formatter::print(Debug::putchar, __VA_ARGS__);																							\
-		BAN::Formatter::print(Debug::putchar, "\r\n");																								\
-		Debug::DebugLock::unlock();																													\
+#define dprintln(...)										\
+	do {													\
+		Debug::DebugLock::lock();							\
+		Debug::print_prefix(__FILE__, __LINE__);				\
+		BAN::Formatter::print(Debug::putchar, __VA_ARGS__);	\
+		BAN::Formatter::print(Debug::putchar, "\r\n");		\
+		Debug::DebugLock::unlock();							\
 	} while(false)
 
 #define dwarnln(...)										\
@@ -36,6 +35,7 @@ namespace Debug
 {
 	void dump_stack_trace();
 	void putchar(char);
+	void print_prefix(const char*, int);
 
 	class DebugLock
 	{
diff --git a/kernel/include/kernel/PIT.h b/kernel/include/kernel/PIT.h
deleted file mode 100644
index 0befacd9b5..0000000000
--- a/kernel/include/kernel/PIT.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-#define PIT_IRQ 0
-
-namespace PIT
-{
-
-	uint64_t ms_since_boot();
-	void initialize();
-	void sleep(uint64_t);
-
-}
\ No newline at end of file
diff --git a/kernel/include/kernel/Timer/PIT.h b/kernel/include/kernel/Timer/PIT.h
new file mode 100644
index 0000000000..09025ccf85
--- /dev/null
+++ b/kernel/include/kernel/Timer/PIT.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <kernel/Timer/Timer.h>
+#include <stdint.h>
+
+#define PIT_IRQ 0
+
+namespace Kernel
+{
+
+	class PIT final : public Timer
+	{
+	public:
+		static BAN::ErrorOr<BAN::UniqPtr<PIT>> create();
+
+		virtual uint64_t ms_since_boot() const override;
+		virtual void sleep(uint64_t) const override;
+
+	private:
+		void initialize();
+	};
+
+}
\ No newline at end of file
diff --git a/kernel/include/kernel/Timer/Timer.h b/kernel/include/kernel/Timer/Timer.h
new file mode 100644
index 0000000000..e72450f55b
--- /dev/null
+++ b/kernel/include/kernel/Timer/Timer.h
@@ -0,0 +1,36 @@
+#pragma once
+
+#include <BAN/UniqPtr.h>
+#include <BAN/Vector.h>
+
+namespace Kernel
+{
+
+	class Timer
+	{
+	public:
+		virtual ~Timer() {};
+		virtual uint64_t ms_since_boot() const = 0;
+		virtual void sleep(uint64_t) const = 0;
+	};
+
+	class TimerHandler
+	{
+	public:
+		static void initialize();
+		static TimerHandler& get();
+		static bool is_initialized();
+
+		uint64_t ms_since_boot() const;
+		void sleep(uint64_t) const;
+
+	private:
+		TimerHandler() = default;
+
+		void initialize_timers();
+
+	private:
+		BAN::Vector<BAN::UniqPtr<Timer>> m_timers;
+	};
+
+}
\ No newline at end of file
diff --git a/kernel/kernel/Debug.cpp b/kernel/kernel/Debug.cpp
index ae88f12b80..12295f96cc 100644
--- a/kernel/kernel/Debug.cpp
+++ b/kernel/kernel/Debug.cpp
@@ -3,6 +3,7 @@
 #include <kernel/Serial.h>
 #include <kernel/SpinLock.h>
 #include <kernel/Terminal/TTY.h>
+#include <kernel/Timer/Timer.h>
 
 namespace Debug
 {
@@ -55,6 +56,11 @@ namespace Debug
 			return Kernel::TTY::putchar_current(ch);
 	}
 
+	void print_prefix(const char* file, int line)
+	{
+		auto ms_since_boot = Kernel::TimerHandler::is_initialized() ? Kernel::TimerHandler::get().ms_since_boot() : 0;
+		BAN::Formatter::print(Debug::putchar, "[{5}.{3}] {}:{}: ", ms_since_boot / 1000, ms_since_boot % 1000, file, line);
+	}
 
 	static Kernel::RecursiveSpinLock s_debug_lock;
 
diff --git a/kernel/kernel/FS/DevFS/FileSystem.cpp b/kernel/kernel/FS/DevFS/FileSystem.cpp
index 5ec1db3ff6..8837fa7fed 100644
--- a/kernel/kernel/FS/DevFS/FileSystem.cpp
+++ b/kernel/kernel/FS/DevFS/FileSystem.cpp
@@ -4,6 +4,7 @@
 #include <kernel/FS/RamFS/Inode.h>
 #include <kernel/LockGuard.h>
 #include <kernel/Process.h>
+#include <kernel/Timer/Timer.h>
 
 namespace Kernel
 {
@@ -45,7 +46,7 @@ namespace Kernel
 					);
 					s_instance->m_device_lock.unlock();
 
-					PIT::sleep(1);
+					Kernel::TimerHandler::get().sleep(1);
 				}
 			}, nullptr
 		);
diff --git a/kernel/kernel/Input/PS2Controller.cpp b/kernel/kernel/Input/PS2Controller.cpp
index 8a6cf088a8..1c25beb06d 100644
--- a/kernel/kernel/Input/PS2Controller.cpp
+++ b/kernel/kernel/Input/PS2Controller.cpp
@@ -6,6 +6,7 @@
 #include <kernel/Input/PS2Keyboard.h>
 #include <kernel/InterruptController.h>
 #include <kernel/IO.h>
+#include <kernel/Timer/Timer.h>
 
 namespace Kernel::Input
 {
@@ -107,8 +108,8 @@ namespace Kernel::Input
 	{
 		if (device == 1)
 			IO::outb(PS2::IOPort::COMMAND, PS2::Command::WRITE_TO_SECOND_PORT);
-		uint64_t timeout = PIT::ms_since_boot() + s_device_timeout_ms;
-		while (PIT::ms_since_boot() < timeout)
+		uint64_t timeout = TimerHandler::get().ms_since_boot() + s_device_timeout_ms;
+		while (TimerHandler::get().ms_since_boot() < timeout)
 		{
 			if (!(IO::inb(PS2::IOPort::STATUS) & PS2::Status::INPUT_FULL))
 			{
@@ -121,8 +122,8 @@ namespace Kernel::Input
 
 	static BAN::ErrorOr<uint8_t> device_read_byte()
 	{
-		uint64_t timeout = PIT::ms_since_boot() + s_device_timeout_ms;
-		while (PIT::ms_since_boot() < timeout)
+		uint64_t timeout = TimerHandler::get().ms_since_boot() + s_device_timeout_ms;
+		while (TimerHandler::get().ms_since_boot() < timeout)
 			if (IO::inb(PS2::IOPort::STATUS) & PS2::Status::OUTPUT_FULL)
 				return IO::inb(PS2::IOPort::DATA);
 		return BAN::Error::from_error_code(ErrorCode::PS2_Timeout);
diff --git a/kernel/kernel/Process.cpp b/kernel/kernel/Process.cpp
index e1c46afbd2..0f809cea24 100644
--- a/kernel/kernel/Process.cpp
+++ b/kernel/kernel/Process.cpp
@@ -8,6 +8,7 @@
 #include <kernel/Memory/PageTableScope.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
+#include <kernel/Timer/Timer.h>
 #include <LibELF/ELF.h>
 #include <LibELF/Values.h>
 
@@ -472,7 +473,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_sleep(int seconds)
 	{
-		PIT::sleep(seconds * 1000);
+		TimerHandler::get().sleep(seconds * 1000);
 		return 0;
 	}
 
@@ -810,7 +811,7 @@ namespace Kernel
 		{
 			case CLOCK_MONOTONIC:
 			{
-				uint64_t time_ms = PIT::ms_since_boot();
+				uint64_t time_ms = TimerHandler::get().ms_since_boot();
 				tp->tv_sec  =  time_ms / 1000;
 				tp->tv_nsec = (time_ms % 1000) * 1000000;
 				break;
diff --git a/kernel/kernel/Scheduler.cpp b/kernel/kernel/Scheduler.cpp
index fc843a9309..7985937db9 100644
--- a/kernel/kernel/Scheduler.cpp
+++ b/kernel/kernel/Scheduler.cpp
@@ -5,6 +5,7 @@
 #include <kernel/InterruptController.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
+#include <kernel/Timer/PIT.h>
 
 #if 1
 	#define VERIFY_STI() ASSERT(interrupts_enabled())
@@ -112,7 +113,7 @@ namespace Kernel
 	{
 		VERIFY_CLI();
 
-		uint64_t current_time = PIT::ms_since_boot();
+		uint64_t current_time = TimerHandler::get().ms_since_boot();
 		while (!m_sleeping_threads.empty() && m_sleeping_threads.front().wake_time <= current_time)
 		{
 			Thread* thread = m_sleeping_threads.front().thread;
diff --git a/kernel/kernel/Storage/ATABus.cpp b/kernel/kernel/Storage/ATABus.cpp
index fbb20c3916..094d2c0f48 100644
--- a/kernel/kernel/Storage/ATABus.cpp
+++ b/kernel/kernel/Storage/ATABus.cpp
@@ -6,6 +6,7 @@
 #include <kernel/Storage/ATADevice.h>
 #include <kernel/Storage/ATABus.h>
 #include <kernel/Storage/ATADefinitions.h>
+#include <kernel/Timer/Timer.h>
 
 namespace Kernel
 {
@@ -99,7 +100,7 @@ namespace Kernel
 	{
 		uint8_t device_index = this->device_index(device);
 		io_write(ATA_PORT_DRIVE_SELECT, 0xA0 | (device_index << 4));
-		PIT::sleep(1);
+		TimerHandler::get().sleep(1);
 	}
 
 	ATABus::DeviceType ATABus::identify(const ATADevice& device, uint16_t* buffer)
@@ -110,7 +111,7 @@ namespace Kernel
 		io_write(ATA_PORT_CONTROL, ATA_CONTROL_nIEN);
 
 		io_write(ATA_PORT_COMMAND, ATA_COMMAND_IDENTIFY);
-		PIT::sleep(1);
+		TimerHandler::get().sleep(1);
 
 		// No device on port
 		if (io_read(ATA_PORT_STATUS) == 0)
@@ -134,7 +135,7 @@ namespace Kernel
 			}
 
 			io_write(ATA_PORT_COMMAND, ATA_COMMAND_IDENTIFY_PACKET);
-			PIT::sleep(1);
+			TimerHandler::get().sleep(1);
 
 			if (auto res = wait(true); res.is_error())
 			{
@@ -303,7 +304,7 @@ namespace Kernel
 			io_write(ATA_PORT_LBA2, (uint8_t)(lba >> 16));
 			io_write(ATA_PORT_COMMAND, ATA_COMMAND_WRITE_SECTORS);
 
-			PIT::sleep(1);
+			TimerHandler::get().sleep(1);
 
 			for (uint32_t sector = 0; sector < sector_count; sector++)
 			{
diff --git a/kernel/kernel/PIT.cpp b/kernel/kernel/Timer/PIT.cpp
similarity index 78%
rename from kernel/kernel/PIT.cpp
rename to kernel/kernel/Timer/PIT.cpp
index 702ba6e15a..1450ae1673 100644
--- a/kernel/kernel/PIT.cpp
+++ b/kernel/kernel/Timer/PIT.cpp
@@ -2,6 +2,7 @@
 #include <kernel/InterruptController.h>
 #include <kernel/IO.h>
 #include <kernel/Scheduler.h>
+#include <kernel/Timer/PIT.h>
 
 #define TIMER0_CTL			0x40
 #define TIMER1_CTL			0x41
@@ -20,7 +21,7 @@
 #define BASE_FREQUENCY		1193182
 #define TICKS_PER_SECOND	1000
 
-namespace PIT
+namespace Kernel
 {
 
 	static volatile uint64_t s_system_time = 0;
@@ -31,12 +32,16 @@ namespace PIT
 		Kernel::Scheduler::get().timer_reschedule();
 	}
 
-	uint64_t ms_since_boot()
+	BAN::ErrorOr<BAN::UniqPtr<PIT>> PIT::create()
 	{
-		return s_system_time;
+		PIT* pit = new PIT;
+		if (pit == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+		pit->initialize();
+		return BAN::UniqPtr<PIT>::adopt(pit);
 	}
 
-	void initialize()
+	void PIT::initialize()
 	{
 		constexpr uint16_t timer_reload = BASE_FREQUENCY / TICKS_PER_SECOND;
 	
@@ -50,7 +55,12 @@ namespace PIT
 		InterruptController::get().enable_irq(PIT_IRQ);
 	}
 
-	void sleep(uint64_t ms)
+	uint64_t PIT::ms_since_boot() const
+	{
+		return s_system_time;
+	}
+
+	void PIT::sleep(uint64_t ms) const
 	{
 		if (ms == 0)
 			return;
diff --git a/kernel/kernel/Timer/Timer.cpp b/kernel/kernel/Timer/Timer.cpp
new file mode 100644
index 0000000000..b5448e2764
--- /dev/null
+++ b/kernel/kernel/Timer/Timer.cpp
@@ -0,0 +1,51 @@
+#include <kernel/Timer/Timer.h>
+#include <kernel/Timer/PIT.h>
+
+namespace Kernel
+{
+
+	static TimerHandler* s_instance = nullptr;
+
+	void TimerHandler::initialize()
+	{
+		ASSERT(s_instance == nullptr);
+		s_instance = new TimerHandler;
+		ASSERT(s_instance);
+		s_instance->initialize_timers();
+	}
+
+	TimerHandler& TimerHandler::get()
+	{
+		ASSERT(s_instance);
+		return *s_instance;
+	}
+
+	bool TimerHandler::is_initialized()
+	{
+		return !!s_instance;
+	}
+
+	void TimerHandler::initialize_timers()
+	{
+		if (auto res = PIT::create(); res.is_error())
+			dwarnln("PIT: {}", res.error());
+		else
+		{
+			MUST(m_timers.emplace_back(BAN::move(res.release_value())));
+			dprintln("PIT initialized");
+		}
+
+		ASSERT(!m_timers.empty());
+	}
+
+	uint64_t TimerHandler::ms_since_boot() const
+	{
+		return m_timers.front()->ms_since_boot();
+	}
+
+	void TimerHandler::sleep(uint64_t ms) const
+	{
+		return m_timers.front()->sleep(ms);
+	}
+
+}
\ No newline at end of file
diff --git a/kernel/kernel/kernel.cpp b/kernel/kernel/kernel.cpp
index 2da4c5fb77..ed67feb563 100644
--- a/kernel/kernel/kernel.cpp
+++ b/kernel/kernel/kernel.cpp
@@ -14,15 +14,13 @@
 #include <kernel/multiboot.h>
 #include <kernel/PCI.h>
 #include <kernel/PIC.h>
-#include <kernel/PIT.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
 #include <kernel/Serial.h>
 #include <kernel/Syscall.h>
 #include <kernel/Terminal/TTY.h>
 #include <kernel/Terminal/VesaTerminalDriver.h>
-
-#include <LibELF/ELF.h>
+#include <kernel/Timer/Timer.h>
 
 extern "C" const char g_kernel_cmdline[];
 
@@ -156,8 +154,8 @@ extern "C" void kernel_main()
 	InterruptController::initialize(cmdline.force_pic);
 	dprintln("Interrupt controller initialized");
 
-	PIT::initialize();
-	dprintln("PIT initialized");
+	TimerHandler::initialize();
+	dprintln("Timers initialized");
 
 	MUST(Scheduler::initialize());
 	dprintln("Scheduler initialized");