X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Ftime.c;h=22ea6181e45bbbcfbbbb6be36eca6b094eb28656;hb=37de13c0c8c88fa6edba679c20becec15547533e;hp=3a13904f819d0776793194cee9f37f7c474166de;hpb=8bc40333b1401d7616b225945fee53d972c2f418;p=tpg%2Facess2.git diff --git a/Kernel/arch/x86/time.c b/Kernel/arch/x86/time.c index 3a13904f..22ea6181 100644 --- a/Kernel/arch/x86/time.c +++ b/Kernel/arch/x86/time.c @@ -3,53 +3,110 @@ * Timekeeping * arch/x86/time.c */ -#include +#include // === 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; }