dev, kernel: scheduler, timer: hw timer and scheduler improvements.

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>

10 files changed, 72 insertions, 61 deletions

diff --git a/dev/boot/BootKit/Qr.h b/dev/boot/BootKit/Qr.h
index 231fcee7..1bf9fa3d 100644
--- a/dev/boot/BootKit/Qr.h
+++ b/dev/boot/BootKit/Qr.h
@@ -957,8 +957,8 @@ namespace qr
 		NE_COPY_DEFAULT(QrDelegate)
 
 		/// @brief Draw method delegate.
-		template <int V>
-		bool draw(Qr<V>& subject, int x, int y) noexcept
+		template <Int32 V>
+		bool draw(Qr<V>& subject, Int32 x, Int32 y) noexcept
 		{
 			return subject.draw(x, y);
 		}
diff --git a/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc b/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc
index 3b98e9e8..1f865057 100644
--- a/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc
+++ b/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc
@@ -219,17 +219,9 @@ namespace Kernel::HAL
 
 			kApicBaseAddress = kMADTBlock->Address;
 
-			constexpr auto kMemoryAPStart = 0x7C000;
-			Char*		   ptr_ap_code	  = reinterpret_cast<Char*>(kMemoryAPStart);
-
-			mm_map_page(ptr_ap_code, ptr_ap_code, kMMFlagsWr | kMMFlagsPCD);
-
-			SizeT hal_ap_blob_len = hal_ap_blob_end - hal_ap_blob_start;
-
-			rt_copy_memory((Char*)hal_ap_blob_start, ptr_ap_code, hal_ap_blob_len);
-
 			while (Yes)
 			{
+				/// @note Anything bigger than x2APIC type doesn't exist.
 				if (kMADTBlock->List[index].Type > 9 ||
 					kSMPCount > kSchedProcessLimitPerTeam)
 					break;
@@ -243,17 +235,6 @@ namespace Kernel::HAL
 					kAPICLocales[kSMPCount] = kMADTBlock->List[kSMPCount].LAPIC.ProcessorID;
 					(void)(kout << "SMP: APIC ID: " << number(kAPICLocales[kSMPCount]) << kendl);
 
-					// I'll just make the AP start from scratch here.
-
-					hal_send_start_ipi(kApicBaseAddress, kAPICLocales[kSMPCount]);
-
-					HardwareTimer timer(Kernel::rtl_ms(10));
-					timer.Wait();
-
-					/// TODO: HAL helper to create an address.
-
-					hal_send_sipi(kApicBaseAddress, kAPICLocales[kSMPCount], (UInt8)(((UIntPtr)ptr_ap_code) >> 12));
-
 					++kSMPCount;
 					break;
 				}
@@ -264,7 +245,7 @@ namespace Kernel::HAL
 				++index;
 			}
 
-			(void)(kout << "SMP: number of APs: " << number(kSMPCount) << kendl);
+			(void)(kout << "SMP: Number of APs: " << number(kSMPCount) << kendl);
 
 			// Kernel is now SMP aware.
 			// That means that the scheduler is now available (on MP Kernels)
diff --git a/dev/kernel/HALKit/AMD64/HalDebugOutput.cc b/dev/kernel/HALKit/AMD64/HalDebugOutput.cc
index b69614fd..84c8c348 100644
--- a/dev/kernel/HALKit/AMD64/HalDebugOutput.cc
+++ b/dev/kernel/HALKit/AMD64/HalDebugOutput.cc
@@ -121,6 +121,11 @@ namespace Kernel
 
 			x += kFontSizeX;
 
+			if (x > kHandoverHeader->f_GOP.f_Width)
+			{
+				x = kFontSizeX;
+			}
+
 			if (y > kHandoverHeader->f_GOP.f_Height)
 			{
 				y = kFontSizeY;
diff --git a/dev/kernel/HALKit/AMD64/HalDescriptorLoader.cc b/dev/kernel/HALKit/AMD64/HalDescriptorLoader.cc
index c0c7dfcf..f205e766 100644
--- a/dev/kernel/HALKit/AMD64/HalDescriptorLoader.cc
+++ b/dev/kernel/HALKit/AMD64/HalDescriptorLoader.cc
@@ -107,10 +107,10 @@ namespace Kernel::HAL
 		idt.Limit = sizeof(::Kernel::Detail::AMD64::InterruptDescriptorAMD64) *
 					(kKernelIdtSize);
 
-		hal_load_idt(idt);
-
 		Detail::hal_enable_pit(kPITTickForScheduler);
 
+		hal_load_idt(idt);
+
 		rt_sti();
 	}
 
diff --git a/dev/kernel/HALKit/AMD64/HalKernelMain.cc b/dev/kernel/HALKit/AMD64/HalKernelMain.cc
index d59e9e86..0c680f97 100644
--- a/dev/kernel/HALKit/AMD64/HalKernelMain.cc
+++ b/dev/kernel/HALKit/AMD64/HalKernelMain.cc
@@ -19,8 +19,6 @@
 
 EXTERN_C Kernel::VoidPtr kInterruptVectorTable[];
 
-STATIC Kernel::Array<UserProcessTeam, kSchedTeamCount> kTeams;
-
 STATIC Kernel::Void hal_pre_init_scheduler() noexcept
 {
 	for (Kernel::SizeT i = 0U; i < Kernel::UserProcessScheduler::The().CurrentTeam().AsArray().Count(); ++i)
@@ -98,11 +96,13 @@ EXTERN_C Kernel::Void hal_real_init(Kernel::Void) noexcept
 
 	idt_loader.Load(idt_reg);
 
-	/// after the scheduler runs, we must look over teams, every 200ms in order to schedule every process according to their affinity fairly.
+	/// after the scheduler runs, we must look over teams, every 5000s in order to schedule every process according to their affinity fairly.
+
+	auto constexpr kSchedTeamSwitchMS = 5U; /// @brief Team switch time in milliseconds.
 
-	auto constexpr kSchedTeamSwitchMS = 200U; /// @brief Team switch time in milliseconds.
+	Kernel::HardwareTimer timer(rtl_milliseconds(kSchedTeamSwitchMS));
 
-	Kernel::HardwareTimer timer(rtl_ms(kSchedTeamSwitchMS));
+	STATIC Kernel::Array<UserProcessTeam, kSchedTeamCount> kTeams;
 
 	SizeT team_index = 0U;
 
@@ -110,15 +110,16 @@ EXTERN_C Kernel::Void hal_real_init(Kernel::Void) noexcept
 	/// @details Not even round-robin, just a simple loop in this boot core we're at.
 	while (YES)
 	{
-		timer.Wait();
-
-		UserProcessScheduler::The().SwitchTeam(kTeams[team_index]);
-
-		++team_index;
-
-		if (team_index > kSchedTeamCount)
+		if (team_index > (kSchedTeamCount - 1))
 		{
 			team_index = 0U;
 		}
+
+		while (!UserProcessScheduler::The().SwitchTeam(kTeams[team_index]))
+			;
+
+		timer.Wait();
+
+		++team_index;
 	}
 }
diff --git a/dev/kernel/HALKit/AMD64/HalTimerAMD64.cc b/dev/kernel/HALKit/AMD64/HalTimerAMD64.cc
index 72de8eb0..ade41d2f 100644
--- a/dev/kernel/HALKit/AMD64/HalTimerAMD64.cc
+++ b/dev/kernel/HALKit/AMD64/HalTimerAMD64.cc
@@ -17,10 +17,10 @@
 

 // timer slot 0

 

-#define cHPETCounterRegValue   (0x00)

-#define cHPETConfigRegValue	   (0x20)

-#define cHPETCompRegValue	   (0x24)

-#define cHPETInterruptRegValue (0x2C)

+#define kHPETCounterRegValue   (0x00)

+#define kHPETConfigRegValue	   (0x20)

+#define kHPETCompRegValue	   (0x24)

+#define kHPETInterruptRegValue (0x2C)

 

 ///! BUGS: 0

 ///! @file HalTimer.cc

@@ -53,7 +53,19 @@ HardwareTimer::HardwareTimer(UInt64 ms)
 	auto hpet = (Detail::HPET_BLOCK*)power.Find("HPET").Leak().Leak();

 	MUST_PASS(hpet);

 

-	fDigitalTimer = (UIntPtr*)hpet->address.Address;

+	fDigitalTimer = (UInt8*)hpet->address.Address;

+

+	if (hpet->page_protection)

+	{

+		HAL::mm_map_page((VoidPtr)fDigitalTimer, (VoidPtr)fDigitalTimer, HAL::kMMFlagsWr | HAL::kMMFlagsPCD | HAL::kMMFlagsPwt);

+	}

+

+	// if not enabled yet.

+	if (!(*((volatile UInt64*)((UInt8*)fDigitalTimer + kHPETConfigRegValue)) & (1 << 0)))

+	{

+		*((volatile UInt64*)((UInt8*)fDigitalTimer + kHPETConfigRegValue)) = *((volatile UInt64*)((UInt8*)fDigitalTimer + kHPETConfigRegValue)) | (1 << 0); // enable timer

+		*((volatile UInt64*)((UInt8*)fDigitalTimer + kHPETConfigRegValue)) = *((volatile UInt64*)((UInt8*)fDigitalTimer + kHPETConfigRegValue)) | (1 << 3); // one shot conf

+	}

 }

 

 HardwareTimer::~HardwareTimer()

@@ -62,25 +74,28 @@ HardwareTimer::~HardwareTimer()
 	fWaitFor	  = 0;

 }

 

+/***********************************************************************************/

+/// @brief Wait for the timer to stop spinning.

+/***********************************************************************************/

+

 BOOL HardwareTimer::Wait() noexcept

 {

 	if (fWaitFor < 1)

 		return NO;

 

-	// if not enabled yet.

-	if (!(*(fDigitalTimer + cHPETConfigRegValue) & (1 << 0)))

-	{

-		*(fDigitalTimer + cHPETConfigRegValue) |= (1 << 0); // enable it

-		*(fDigitalTimer + cHPETConfigRegValue) |= (1 << 3); // one shot conf

-	}

+	UInt64 hpet_cap				 = *((volatile UInt64*)(fDigitalTimer + kHPETCounterRegValue));

+	UInt64 femtoseconds_per_tick = (hpet_cap >> 32);

+

+	if (femtoseconds_per_tick == 0)

+		return NO;

 

-	UInt64 ticks = fWaitFor / ((*(fDigitalTimer) >> 32) & __UINT32_MAX__);

-	UInt64 prev	 = *(fDigitalTimer + cHPETCounterRegValue);

+	volatile UInt64* timer = (volatile UInt64*)(fDigitalTimer + kHPETCounterRegValue);

 

-	prev += ticks;

+	UInt64 now	= *timer;

+	UInt64 prev = now + (fWaitFor / femtoseconds_per_tick);

 

-	while (*(fDigitalTimer + cHPETCounterRegValue) < (ticks))

-		;

+	while (*timer < (prev))

+		asm volatile("pause");

 

 	return YES;

 }

diff --git a/dev/kernel/KernelKit/Timer.h b/dev/kernel/KernelKit/Timer.h
index b6d23e6b..1d12876b 100644
--- a/dev/kernel/KernelKit/Timer.h
+++ b/dev/kernel/KernelKit/Timer.h
@@ -60,24 +60,24 @@ namespace Kernel
 		BOOL Wait() noexcept override;
 
 	private:
-		UIntPtr* fDigitalTimer{nullptr};
+		volatile UInt8* fDigitalTimer{nullptr};
 		Int64	 fWaitFor{0};
 	};
 
-	inline Int64 rtl_ms(Int64 time)
+	inline Int64 rtl_microseconds(Int64 time)
 	{
 		if (time < 0)
 			return 0;
 
 		// TODO: nanoseconds maybe?
-		return kTimeUnit * kTimeUnit * time;
+		return kTimeUnit * time;
 	}
 
-	inline Int64 rtl_seconds(Int64 time)
+	inline Int64 rtl_milliseconds(Int64 time)
 	{
 		if (time < 0)
 			return 0;
 
-		return kTimeUnit * rtl_ms(time);
+		return kTimeUnit * kTimeUnit * time;
 	}
 } // namespace Kernel
diff --git a/dev/kernel/KernelKit/UserProcessScheduler.h b/dev/kernel/KernelKit/UserProcessScheduler.h
index 53ee3476..ec16a0e2 100644
--- a/dev/kernel/KernelKit/UserProcessScheduler.h
+++ b/dev/kernel/KernelKit/UserProcessScheduler.h
@@ -20,7 +20,7 @@
 #define kSchedMinMicroTime		  (AffinityKind::kStandard)
 #define kSchedInvalidPID		  (-1)
 #define kSchedProcessLimitPerTeam (32U)
-#define kSchedTeamCount			  (512U)
+#define kSchedTeamCount			  (256U)
 
 #define kSchedMaxMemoryLimit gib_cast(128) /* max physical memory limit */
 #define kSchedMaxStackSz	 mib_cast(8)   /* maximum stack size */
diff --git a/dev/kernel/src/BinaryMutex.cc b/dev/kernel/src/BinaryMutex.cc
index c149b362..f9faadd2 100644
--- a/dev/kernel/src/BinaryMutex.cc
+++ b/dev/kernel/src/BinaryMutex.cc
@@ -67,7 +67,7 @@ namespace Kernel
 	/***********************************************************************************/
 	BOOL BinaryMutex::WaitForProcess(const Int16& sec) noexcept
 	{
-		HardwareTimer hw_timer(rtl_seconds(sec));
+		HardwareTimer hw_timer(rtl_milliseconds(sec));
 		hw_timer.Wait();
 
 		return !this->IsLocked();
diff --git a/dev/kernel/src/UserProcessScheduler.cc b/dev/kernel/src/UserProcessScheduler.cc
index 8df98f87..7aded611 100644
--- a/dev/kernel/src/UserProcessScheduler.cc
+++ b/dev/kernel/src/UserProcessScheduler.cc
@@ -31,8 +31,10 @@ namespace Kernel
 
 	STATIC UInt32 kLastExitCode = 0U;
 
+	STATIC BOOL kCurrentlySwitching = No;
+
 	/***********************************************************************************/
-	/// @brief External reference of the thread scheduler.
+	/// @brief Scheduler itself.
 	/***********************************************************************************/
 
 	STATIC UserProcessScheduler kScheduler;
@@ -470,6 +472,8 @@ namespace Kernel
 			return 0UL;
 		}
 
+		kCurrentlySwitching = Yes;
+
 		for (; process_index < mTeam.AsArray().Capacity(); ++process_index)
 		{
 			auto& process = mTeam.AsArray()[process_index];
@@ -502,6 +506,8 @@ namespace Kernel
 			}
 		}
 
+		kCurrentlySwitching = No;
+
 		return process_index;
 	}
 
@@ -524,6 +530,9 @@ namespace Kernel
 		if (team.AsArray().Count() < 1)
 			return No;
 
+		if (kCurrentlySwitching)
+			return No;
+
 		kScheduler.mTeam = team;
 
 		return Yes;