Kernel - Reworked x86 physical memory allocation

[tpg/acess2.git] / Kernel / arch / x86 / time.c

diff --git a/Kernel/arch/x86/time.c b/Kernel/arch/x86/time.c
index 3a13904..22ea618 100644 (file)
--- a/Kernel/arch/x86/time.c
+++ b/Kernel/arch/x86/time.c
@@ -3,53 +3,110 @@
  * Timekeeping
  * arch/x86/time.c
  */
-#include <common.h>
+#include <acess.h>
 
 // === MACROS ===
-#define TIMER_FREQ     1024    //Hz
+#define        TIMER_QUANTUM   100
+// 2^(15-rate), 15: 1HZ, 5: 1024Hz, 2: 8192Hz
+// (Max: 15, Min: 2) - 15 = 1Hz, 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      // 2Hz
+//#define TIMER_RATE   15      // 1HZ
+#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)
 
-// === PROTOTYPES ===
-void   Time_Interrupt();
+// === IMPORTS ===
+extern volatile Sint64 giTimestamp;
+extern volatile Uint64 giTicks;
+extern volatile Uint64 giPartMiliseconds;
+extern void    Timer_CallTimers(void);
 
 // === GLOBALS ===
-Uint64 giTicks = 0;
-Sint64 giTimestamp = 0;
-Uint64 giPartMiliseconds = 0;
+volatile Uint64        giTime_TSCAtLastTick = 0;
+volatile Uint64        giTime_TSCPerTick = 0;
+
+// === PROTOTYPES ===
+//Sint64       now(void);
+ int   Time_Setup(void);
+void   Time_Interrupt(int);
+Uint64 Time_ReadTSC(void);
 
 // === CODE ===
 /**
- * \fn int Time_Setup()
+ * \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
  */
-int Time_Setup()
+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;
+       outb(0x71, val);        // Update the timer rate
+               
        // Enable IRQ8
        outb(0x70, 0x0B);       // Set the index to register B
        val = inb(0x71);        // Read the current value of register B
        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);
+       
+       // Make sure the RTC actually fires
+       outb(0x70, 0x0C); // Select register C
+       inb(0x71);      // Just throw away contents.
+       
        return 0;
 }
 
 /**
- * \fn void Time_Interrupt()
  * \brief Called on the timekeeping IRQ
+ * \param irq  IRQ number (unused)
  */
-void Time_Interrupt()
+void Time_Interrupt(int irq)
 {
+       //Log("RTC Tick");
+       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;
@@ -57,13 +114,36 @@ void Time_Interrupt()
                giTimestamp ++;
                giPartMiliseconds -= 0x80000000;
        }
+       
+       Timer_CallTimers();
+
+       // Make sure the RTC Fires again
+       outb(0x70, 0x0C); // Select register C
+       inb(0x71);      // Just throw away contents.
 }
 
+#if 0
 /**
- * \fn Sint64 now()
- * \brief Return the current timestamp
+ * \fn void Time_TimerThread(void)
  */
-Sint64 now()
+void Time_TimerThread(void)
+{
+       Sint64  next;
+       Threads_SetName("TIMER");
+       
+       next = giTimestamp + TIMER_QUANTUM;
+       for(;;)
+       {
+               while(giTimestamp < next)       Threads_Yield();
+               next = giTimestamp + TIMER_QUANTUM;     
+               Timer_CallTimers();
+       }
+}
+#endif
+
+Uint64 Time_ReadTSC(void)
 {
-       return giTimestamp;
+       Uint32  a, d;
+       __asm__ __volatile__ ("rdtsc" : "=a" (a), "=d" (d));
+       return ((Uint64)d << 32) | a;
 }