From: John Hodge <tpg@mutabah.net>
Date: Sat, 12 Feb 2011 04:29:50 +0000 (+0800)
Subject: TSC backed timekeeping, 64-bit integer printing
X-Git-Tag: rel0.07~10
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=09e044c2338f194d0f179aff6358bf9fd0739768;p=tpg%2Facess2.git

TSC backed timekeeping, 64-bit integer printing

- Improved 64-bit division (using the FPU)
---

diff --git a/Kernel/arch/x86/lib.c b/Kernel/arch/x86/lib.c
index 796baa43..b73cc6a2 100644
--- a/Kernel/arch/x86/lib.c
+++ b/Kernel/arch/x86/lib.c
@@ -282,6 +282,21 @@ Uint64 __udivdi3(Uint64 Num, Uint64 Den)
 	if(Num < Den*2)	return 1;
 	if(Num == Den*2)	return 2;
 	
+	#if 1
+	i = 0;	// Shut up
+	P[0] = Num;
+	P[1] = Den;
+	__asm__ __volatile__ (
+		"fildq %2\n\t"	// Num
+		"fildq %1\n\t"	// Den
+		"fdivp\n\t"
+		"fistpq %0"
+		: "=m" (q)
+		: "m" (P[0]), "m" (P[1])
+		);
+		
+	//Log("%llx / %llx = %llx\n", Num, Den, q);
+	#else
 	// Restoring division, from wikipedia
 	// http://en.wikipedia.org/wiki/Division_(digital)
 	P[0] = Num;	P[1] = 0;
@@ -303,6 +318,7 @@ Uint64 __udivdi3(Uint64 Num, Uint64 Den)
 			P[1] += Den;
 		}
 	}
+	#endif
 	
 	return q;
 }
diff --git a/Kernel/arch/x86/time.c b/Kernel/arch/x86/time.c
index 63d4e00b..37cc5e35 100644
--- a/Kernel/arch/x86/time.c
+++ b/Kernel/arch/x86/time.c
@@ -9,23 +9,48 @@
 #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
-//#define TIMER_RATE	12
-//#define TIMER_RATE	15
+//#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	((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 ===
+Sint64	now(void);
+ int	Time_Setup(void);
 void	Time_Interrupt(int);
+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
@@ -74,6 +99,14 @@ int Time_Setup(void)
 void Time_Interrupt(int irq)
 {
 	//Log("RTC Tick");
+	Uint64	curTSC = Time_ReadTSC();
+	
+	if( giTime_TSCAtLastTick )
+	{
+		giTime_TSCPerTick = curTSC - giTime_TSCAtLastTick;
+		//Log("curTSC = %lli, giTime_TSCPerTick = %lli", curTSC, giTime_TSCPerTick);
+	}
+	giTime_TSCAtLastTick = curTSC;
 	
 	giTicks ++;
 	giTimestamp += MS_PER_TICK_WHOLE;
@@ -108,3 +141,10 @@ void Time_TimerThread(void)
 	}
 }
 #endif
+
+Uint64 Time_ReadTSC(void)
+{
+	Uint32	a, d;
+	__asm__ __volatile__ ("rdtsc" : "=a" (a), "=d" (d));
+	return ((Uint64)d << 32) | a;
+}
diff --git a/Kernel/include/acess.h b/Kernel/include/acess.h
index 1f969f8a..95acb313 100644
--- a/Kernel/include/acess.h
+++ b/Kernel/include/acess.h
@@ -346,7 +346,7 @@ extern char	**str_split(const char *__str, char __ch);
 extern char	*strchr(const char *__s, int __c);
 extern int	strpos(const char *Str, char Ch);
 extern int	strpos8(const char *str, Uint32 search);
-extern void	itoa(char *buf, Uint num, int base, int minLength, char pad);
+extern void	itoa(char *buf, Uint64 num, int base, int minLength, char pad);
 extern int	atoi(const char *string);
 extern int	ReadUTF8(Uint8 *str, Uint32 *Val);
 extern int	WriteUTF8(Uint8 *str, Uint32 Val);
diff --git a/Kernel/lib.c b/Kernel/lib.c
index bc32a0ce..4c6ab188 100644
--- a/Kernel/lib.c
+++ b/Kernel/lib.c
@@ -15,7 +15,7 @@ const short DAYS_BEFORE[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 3
 
 // === PROTOTYPES ===
  int	atoi(const char *string);
-void	itoa(char *buf, Uint num, int base, int minLength, char pad);
+void	itoa(char *buf, Uint64 num, int base, int minLength, char pad);
  int	vsnprintf(char *__s, size_t __maxlen, const char *__format, va_list args);
  int	sprintf(char *__s, const char *__format, ...);
  int	tolower(int c);
@@ -145,12 +145,12 @@ int atoi(const char *string)
 
 static const char cUCDIGITS[] = "0123456789ABCDEF";
 /**
- * \fn void itoa(char *buf, Uint num, int base, int minLength, char pad)
+ * \fn void itoa(char *buf, Uint64 num, int base, int minLength, char pad)
  * \brief Convert an integer into a character string
  */
-void itoa(char *buf, Uint num, int base, int minLength, char pad)
+void itoa(char *buf, Uint64 num, int base, int minLength, char pad)
 {
-	char	tmpBuf[BITS];
+	char	tmpBuf[64+1];
 	 int	pos=0, i;
 
 	// Sanity check
diff --git a/Kernel/time.c b/Kernel/time.c
index dcc4f79e..9ddf26a3 100644
--- a/Kernel/time.c
+++ b/Kernel/time.c
@@ -27,15 +27,6 @@ Uint64	giPartMiliseconds = 0;
 tTimer	gTimers[NUM_TIMERS];	// TODO: Replace by a ring-list timer
 
 // === CODE ===
-/**
- * \fn Sint64 now()
- * \brief Return the current timestamp
- */
-Sint64 now(void)
-{
-	return giTimestamp;
-}
-
 /**
  * \fn void Timer_CallTimers()
  */