X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Ftime.c;h=9b59b30b100c94f68cc184bcc2f386450e5b32e9;hb=5473bdfc429d224c40e37ff7065a8dbad119fa1e;hp=77683b558ef3d409a2a5d91bf3cbaca21b8fabe7;hpb=dea6bcf35a3f52396724d74e47f71cb3afade37c;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/time.c b/Kernel/arch/x86/time.c
index 77683b55..9b59b30b 100644
--- a/Kernel/arch/x86/time.c
+++ b/Kernel/arch/x86/time.c
@@ -7,22 +7,49 @@
 
 // === MACROS ===
 #define	TIMER_QUANTUM	100
-// 2^(15-rate), 15: 1HZ, 5: 1024Hz, 2: 8192Hz
-#define TIMER_RATE	12	// (Max: 15, Min: 2) - 15 = 1Hz, 13 = 4Hz, 12 = 8Hz, 11 = 16Hz 10 = 32Hz, 2
+// 2^(15-rate), 14: 2Hz, 5: 1024Hz, 2: 8192Hz
+// (Max: 14, Min: 2) - 14 = 2Hz, 13 = 4Hz, 12 = 8Hz, 11 = 16Hz 10 = 32Hz, 2 = 8192Hz
+//#define TIMER_RATE	10	// 32 Hz
+//#define TIMER_RATE	12	// 8 Hz
+#define TIMER_RATE	14	// 2 Hz - Lowest
 #define TIMER_FREQ	(0x8000>>TIMER_RATE)	//Hz
 #define MS_PER_TICK_WHOLE	(1000/(TIMER_FREQ))
-#define MS_PER_TICK_FRACT	((Uint64)(1000*TIMER_FREQ-((Uint64)MS_PER_TICK_WHOLE)*0x80000000/TIMER_FREQ))
+#define MS_PER_TICK_FRACT	((0x80000000*(1000%TIMER_FREQ))/TIMER_FREQ)
 
 // === IMPORTS ===
-extern Sint64	giTimestamp;
-extern Uint64	giTicks;
-extern Uint64	giPartMiliseconds;
+extern volatile Sint64	giTimestamp;
+extern volatile Uint64	giTicks;
+extern volatile Uint64	giPartMiliseconds;
 extern void	Timer_CallTimers(void);
 
+// === GLOBALS ===
+volatile Uint64	giTime_TSCAtLastTick = 0;
+volatile Uint64	giTime_TSCPerTick = 0;
+
 // === PROTOTYPES ===
-void	Time_Interrupt(int);
+//Sint64	now(void);
+ int	Time_Setup(void);
+void	Time_Interrupt(int IRQ, void *Ptr);
+Uint64	Time_ReadTSC(void);
 
 // === CODE ===
+/**
+ * \fn Sint64 now()
+ * \brief Return the current timestamp
+ */
+Sint64 now(void)
+{
+	Uint64	tsc = Time_ReadTSC();
+	tsc -= giTime_TSCAtLastTick;
+	tsc *= MS_PER_TICK_WHOLE;
+	if( giTime_TSCPerTick ) {
+		tsc /= giTime_TSCPerTick;
+	}
+	else
+		tsc = 0;
+	return giTimestamp + tsc;
+}
+
 /**
  * \fn int Time_Setup(void)
  * \brief Sets the system time from the Realtime-Clock
@@ -31,15 +58,18 @@ int Time_Setup(void)
 {
 	Uint8	val;
 	
+	Log_Log("Timer", "RTC Timer firing at %iHz (%i divisor), %i.0x%08x",
+		TIMER_FREQ, TIMER_RATE, MS_PER_TICK_WHOLE, MS_PER_TICK_FRACT);
+	
 	outb(0x70, inb(0x70)&0x7F);	// Disable NMIs
 	__asm__ __volatile__ ("cli");	// Disable normal interrupts
 	
 	// Set IRQ8 firing rate
 	outb(0x70, 0x0A);	// Set the index to register A
 	val = inb(0x71); // Get the current value of register A
-	outb(0x70, 0x0A); // Reset index to A
 	val &= 0xF0;
-	val |= TIMER_RATE;
+	val |= TIMER_RATE+1;
+	outb(0x70, 0x0A); // Reset index to A
 	outb(0x71, val);	// Update the timer rate
 		
 	// Enable IRQ8
@@ -48,20 +78,32 @@ int Time_Setup(void)
 	outb(0x70, 0x0B);	// Set the index again (a read will reset the index to register D)
 	outb(0x71, val | 0x40);	// Write the previous value or'd with 0x40. This turns on bit 6 of register D
 	
-	__asm__ __volatile__ ("sti");	// Disable normal interrupts
-	outb(0x70, inb(0x70)|0x80);	// Disable NMIs
+	__asm__ __volatile__ ("sti");	// Re-enable normal interrupts
+	outb(0x70, inb(0x70)|0x80);	// Re-enable NMIs
 	
 	// Install IRQ Handler
-	IRQ_AddHandler(8, Time_Interrupt);
+	IRQ_AddHandler(8, Time_Interrupt, NULL);
+	
+	// Make sure the RTC actually fires
+	outb(0x70, 0x0C); // Select register C
+	inb(0x71);	// Just throw away contents.
+	
 	return 0;
 }
 
 /**
- * \fn void Time_Interrupt(void)
  * \brief Called on the timekeeping IRQ
  */
-void Time_Interrupt(int irq)
+void Time_Interrupt(int IRQ, void *Ptr)
 {
+	Uint64	curTSC = Time_ReadTSC();
+	
+	if( giTime_TSCAtLastTick )
+	{
+		giTime_TSCPerTick = curTSC - giTime_TSCAtLastTick;
+	}
+	giTime_TSCAtLastTick = curTSC;
+	
 	giTicks ++;
 	giTimestamp += MS_PER_TICK_WHOLE;
 	giPartMiliseconds += MS_PER_TICK_FRACT;
@@ -77,21 +119,9 @@ void Time_Interrupt(int irq)
 	inb(0x71);	// Just throw away contents.
 }
 
-#if 0
-/**
- * \fn void Time_TimerThread(void)
- */
-void Time_TimerThread(void)
+Uint64 Time_ReadTSC(void)
 {
-	Sint64	next;
-	Threads_SetName("TIMER");
-	
-	next = giTimestamp + TIMER_QUANTUM;
-	for(;;)
-	{
-		while(giTimestamp < next)	Threads_Yield();
-		next = giTimestamp + TIMER_QUANTUM;	
-		Timer_CallTimers();
-	}
+	Uint32	a, d;
+	__asm__ __volatile__ ("rdtsc" : "=a" (a), "=d" (d));
+	return ((Uint64)d << 32) | a;
 }
-#endif