X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Flib.c;h=2160805c4e81ee298712a01b7a699ecb2bbbbdfb;hb=02cbaac1233be9c5228973a787431fa5e0aa178e;hp=7e79c711f721b8796c4dab16098d492a70ac181e;hpb=6749674b892a0865abc22f9a6ec9a624ff40a283;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/lib.c b/Kernel/arch/x86/lib.c
index 7e79c711..2160805c 100644
--- a/Kernel/arch/x86/lib.c
+++ b/Kernel/arch/x86/lib.c
@@ -2,18 +2,143 @@
  * AcessOS Microkernel Version
  * lib.c
  */
-#include <common.h>
+#include <acess.h>
+#include <threads.h>
+
+#define TRACE_LOCKS	1
+
+extern int	GetCPUNum(void);
 
 // === CODE ===
-void Spinlock(int *lock)
+/**
+ * \brief Determine if a short spinlock is locked
+ * \param Lock	Lock pointer
+ */
+int IS_LOCKED(struct sShortSpinlock *Lock)
 {
-	 int	v = 1;
-	while(v)	__asm__ __volatile__ ("lock xchgl %%eax, (%%edi)":"=a"(v):"a"(1),"D"(lock));
+	return !!Lock->Lock;
 }
 
-void Release(int *lock)
+/**
+ * \brief Check if the current CPU has the lock
+ * \param Lock	Lock pointer
+ */
+int CPU_HAS_LOCK(struct sShortSpinlock *Lock)
 {
-	__asm__ __volatile__ ("lock andl $0, (%0)"::"r"(lock));
+	#if STACKED_LOCKS == 1
+	return Lock->Lock == GetCPUNum() + 1;
+	#elif STACKED_LOCKS == 2
+	return Lock->Lock == Proc_GetCurThread();
+	#else
+	return 0;
+	#endif
+}
+
+/**
+ * \brief Acquire a Short Spinlock
+ * \param Lock	Lock pointer
+ * 
+ * This type of mutex should only be used for very short sections of code,
+ * or in places where a Mutex_* would be overkill, such as appending
+ * an element to linked list (usually two assignement lines in C)
+ * 
+ * \note This type of lock halts interrupts, so ensure that no timing
+ * functions are called while it is held. As a matter of fact, spend as
+ * little time as possible with this lock held
+ * \note If \a STACKED_LOCKS is set, this type of spinlock can be nested
+ */
+void SHORTLOCK(struct sShortSpinlock *Lock)
+{
+	 int	v = 1;
+	#if LOCK_DISABLE_INTS
+	 int	IF;
+	#endif
+	#if STACKED_LOCKS == 1
+	 int	cpu = GetCPUNum() + 1;
+	#elif STACKED_LOCKS == 2
+	void	*thread = Proc_GetCurThread();
+	#endif
+	
+	#if LOCK_DISABLE_INTS
+	// Save interrupt state
+	__ASM__ ("pushf;\n\tpop %0" : "=r"(IF));
+	IF &= 0x200;	// AND out all but the interrupt flag
+	#endif
+	
+	#if STACKED_LOCKS == 1
+	if( Lock->Lock == cpu ) {
+		Lock->Depth ++;
+		return ;
+	}
+	#elif STACKED_LOCKS == 2
+	if( Lock->Lock == thread ) {
+		Lock->Depth ++;
+		return ;
+	}
+	#endif
+	
+	// Wait for another CPU to release
+	while(v) {
+		// CMPXCHG:
+		//  If r/m32 == EAX, set ZF and set r/m32 = r32
+		//  Else, clear ZF and set EAX = r/m32
+		#if STACKED_LOCKS == 1
+		__ASM__("lock cmpxchgl %2, (%3)"
+			: "=a"(v)
+			: "a"(0), "r"(cpu), "r"(&Lock->Lock)
+			);
+		#elif STACKED_LOCKS == 2
+		__ASM__("lock cmpxchgl %2, (%3)"
+			: "=a"(v)
+			: "a"(0), "r"(thread), "r"(&Lock->Lock)
+			);
+		#else
+		__ASM__("xchgl %%eax, (%%edi)":"=a"(v):"a"(1),"D"(&Lock->Lock));
+		#endif
+		
+		#if LOCK_DISABLE_INTS
+		if( v )	__ASM__("sti");	// Re-enable interrupts
+		#endif
+	}
+	
+	#if LOCK_DISABLE_INTS
+	__ASM__("cli");
+	Lock->IF = IF;
+	#endif
+	
+	#if TRACE_LOCKS
+	Log_Log("LOCK", "%p locked by %p\n", Lock, __builtin_return_address(0));
+	#endif
+}
+/**
+ * \brief Release a short lock
+ * \param Lock	Lock pointer
+ */
+void SHORTREL(struct sShortSpinlock *Lock)
+{
+	#if TRACE_LOCKS
+	Log_Log("LOCK", "%p released by %p\n", Lock, __builtin_return_address(0));
+	#endif
+	
+	#if STACKED_LOCKS
+	if( Lock->Depth ) {
+		Lock->Depth --;
+		return ;
+	}
+	#endif
+	
+	#if LOCK_DISABLE_INTS
+	// Lock->IF can change anytime once Lock->Lock is zeroed
+	if(Lock->IF) {
+		Lock->Lock = 0;
+		__ASM__ ("sti");
+	}
+	else {
+		Lock->Lock = 0;
+	}
+	#else
+	Lock->Lock = 0;
+	#endif
 }
 
 // === IO Commands ===
@@ -49,48 +174,55 @@ Uint32 ind(Uint16 Port)
 }
 
 /**
- * \fn void *memset(void *Dest, int Val, Uint Num)
+ * \fn void *memset(void *Dest, int Val, size_t Num)
  * \brief Do a byte granuality set of Dest
  */
-void *memset(void *Dest, int Val, Uint Num)
+void *memset(void *Dest, int Val, size_t Num)
 {
+	Uint32	val = Val&0xFF;
+	val |= val << 8;
+	val |= val << 16;
 	__asm__ __volatile__ (
 		"rep stosl;\n\t"
 		"mov %3, %%ecx;\n\t"
 		"rep stosb"
-		:: "D" (Dest), "a" (Val), "c" (Num/4), "r" (Num&3));
+		:: "D" (Dest), "a" (val), "c" (Num/4), "r" (Num&3));
 	return Dest;
 }
 /**
- * \fn void *memsetd(void *Dest, Uint Val, Uint Num)
+ * \brief Set double words
  */
-void *memsetd(void *Dest, Uint Val, Uint Num)
+void *memsetd(void *Dest, Uint32 Val, size_t Num)
 {
 	__asm__ __volatile__ ("rep stosl" :: "D" (Dest), "a" (Val), "c" (Num));
 	return Dest;
 }
 
 /**
- * \fn int memcmp(const void *m1, const void *m2, Uint Num)
+ * \fn int memcmp(const void *m1, const void *m2, size_t Num)
  * \brief Compare two pieces of memory
  */
-int memcmp(const void *m1, const void *m2, Uint Num)
+int memcmp(const void *m1, const void *m2, size_t Num)
 {
+	if( Num == 0 )	return 0;	// No bytes are always identical
+	
 	while(Num--)
 	{
-		if(*(Uint8*)m1 != *(Uint8*)m2)	break;
+		if(*(Uint8*)m1 != *(Uint8*)m2)
+			return *(Uint8*)m1 - *(Uint8*)m2;
 		m1 ++;
 		m2 ++;
 	}
-	return *(Uint8*)m1 - *(Uint8*)m2;
+	return 0;
 }
 
 /**
- * \fn void *memcpy(void *Dest, void *Src, Uint Num)
+ * \fn void *memcpy(void *Dest, const void *Src, size_t Num)
+ * \brief Copy \a Num bytes from \a Src to \a Dest
  */
-void *memcpy(void *Dest, const void *Src, Uint Num)
+void *memcpy(void *Dest, const void *Src, size_t Num)
 {
-	if((Uint)Dest & 3 || (Uint)Src & 3)
+	if( ((Uint)Dest & 3) || ((Uint)Src & 3) )
 		__asm__ __volatile__ ("rep movsb" :: "D" (Dest), "S" (Src), "c" (Num));
 	else {
 		__asm__ __volatile__ (
@@ -102,9 +234,10 @@ void *memcpy(void *Dest, const void *Src, Uint Num)
 	return Dest;
 }
 /**
- * \fn void *memcpyd(void *Dest, void *Src, Uint Num)
+ * \fn void *memcpyd(void *Dest, const void *Src, size_t Num)
+ * \brief Copy \a Num DWORDs from \a Src to \a Dest
  */
-void *memcpyd(void *Dest, const void *Src, Uint Num)
+void *memcpyd(void *Dest, const void *Src, size_t Num)
 {
 	__asm__ __volatile__ ("rep movsl" :: "D" (Dest), "S" (Src), "c" (Num));
 	return Dest;
@@ -116,10 +249,15 @@ void *memcpyd(void *Dest, const void *Src, Uint Num)
  */
 Uint64 __udivdi3(Uint64 Num, Uint64 Den)
 {
-	Uint64	ret = 0;
+	Uint64	P[2];
+	Uint64	q = 0;
+	 int	i;
 	
-	if(Den == 0)	__asm__ __volatile__ ("int $0x0");	// Call Div by Zero Error
-	if(Den == 1)	return Num;	// Speed Hacks
+	if(Den == 0)	__asm__ __volatile__ ("int $0x0");
+	// Common speedups
+	if(Num <= 0xFFFFFFFF && Den <= 0xFFFFFFFF)
+		return (Uint32)Num / (Uint32)Den;
+	if(Den == 1)	return Num;
 	if(Den == 2)	return Num >> 1;	// Speed Hacks
 	if(Den == 4)	return Num >> 2;	// Speed Hacks
 	if(Den == 8)	return Num >> 3;	// Speed Hacks
@@ -128,19 +266,33 @@ Uint64 __udivdi3(Uint64 Num, Uint64 Den)
 	if(Den == 1024)	return Num >> 10;	// Speed Hacks
 	if(Den == 2048)	return Num >> 11;	// Speed Hacks
 	if(Den == 4096)	return Num >> 12;
+	if(Num < Den)	return 0;
+	if(Num < Den*2)	return 1;
+	if(Num == Den*2)	return 2;
 	
-	if(Num >> 32 == 0 && Den >> 32 == 0)
-		return (Uint32)Num / (Uint32)Den;
-	
-	//Log("__udivdi3: (Num={0x%x:%x}, Den={0x%x:%x})",
-	//	Num>>32, Num&0xFFFFFFFF,
-	//	Den>>32, Den&0xFFFFFFFF);
-	
-	while(Num > Den) {
-		ret ++;
-		Num -= Den;
+	// Restoring division, from wikipedia
+	// http://en.wikipedia.org/wiki/Division_(digital)
+	P[0] = Num;	P[1] = 0;
+	for( i = 64; i--; )
+	{
+		// P <<= 1;
+		P[1] = (P[1] << 1) | (P[0] >> 63);
+		P[0] = P[0] << 1;
+		
+		// P -= Den << 64
+		P[1] -= Den;
+		
+		// P >= 0
+		if( !(P[1] & (1ULL<<63)) ) {
+			q |= (Uint64)1 << (63-i);
+		}
+		else {
+			//q |= 0 << (63-i);
+			P[1] += Den;
+		}
 	}
-	return ret;
+	
+	return q;
 }
 
 /**
@@ -163,9 +315,7 @@ Uint64 __umoddi3(Uint64 Num, Uint64 Den)
 	if(Num >> 32 == 0 && Den >> 32 == 0)
 		return (Uint32)Num % (Uint32)Den;
 	
-	while(Num > Den)
-		Num -= Den;
-	return Num;
+	return Num - __udivdi3(Num, Den) * Den;
 }
 
 Uint16 LittleEndian16(Uint16 Val)
@@ -187,8 +337,16 @@ Uint32 BigEndian32(Uint32 Val)
 
 // --- EXPORTS ---
 EXPORT(memcpy);	EXPORT(memset);
+EXPORT(memcmp);
 //EXPORT(memcpyw);	EXPORT(memsetw);
 EXPORT(memcpyd);	EXPORT(memsetd);
 EXPORT(inb);	EXPORT(inw);	EXPORT(ind);
 EXPORT(outb);	EXPORT(outw);	EXPORT(outd);
 EXPORT(__udivdi3);	EXPORT(__umoddi3);
+
+EXPORT(LittleEndian16);	EXPORT(BigEndian16);
+EXPORT(LittleEndian32);	EXPORT(BigEndian32);
+
+EXPORT(SHORTLOCK);
+EXPORT(SHORTREL);
+EXPORT(IS_LOCKED);