X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Fmm_virt.c;h=7db7ceddea43437fd885abe39253dbd58ed5783d;hb=33427b31d9e6eeb8e5b76ee603429c8deb68733b;hp=cdd071c0cf2369ee5f88f9882064370cf10504f0;hpb=a04d40c6d54762969e12b3e1a3e159b912124525;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/mm_virt.c b/Kernel/arch/x86/mm_virt.c
index cdd071c0..7db7cedd 100644
--- a/Kernel/arch/x86/mm_virt.c
+++ b/Kernel/arch/x86/mm_virt.c
@@ -9,6 +9,7 @@
  * 0xFE - Unused
  * 0xFF - System Calls / Kernel's User Code
  */
+#define DEBUG	1
 #include <common.h>
 #include <mm_phys.h>
 #include <proc.h>
@@ -28,8 +29,6 @@
 #define	TEMP_MAP_ADDR	0xFEFF0000	// Allows 16 "temp" pages
 #define	NUM_TEMP_PAGES	16
 
-#define	USE_COW	1
-
 #define	PF_PRESENT	0x1
 #define	PF_WRITE	0x2
 #define	PF_USER		0x4
@@ -107,10 +106,19 @@ void MM_PageFault(Uint Addr, Uint ErrorCode, tRegs *Regs)
 	 && gaPageTable[Addr>>12] & PF_COW )
 	{
 		tPAddr	paddr;
-		paddr = MM_DuplicatePage( Addr );
-		MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
-		gaPageTable[Addr>>12] &= PF_USER;
-		gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
+		if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
+		{
+			gaPageTable[Addr>>12] &= ~PF_COW;
+			gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
+		}
+		else
+		{
+			paddr = MM_DuplicatePage( Addr );
+			MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
+			gaPageTable[Addr>>12] &= PF_USER;
+			gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
+		}
+		//LOG("Duplicated page at %p to 0x%x", Addr&~0xFFF, gaPageTable[Addr>>12]);
 		INVLPG( Addr & ~0xFFF );
 		//LEAVE('-')
 		return;
@@ -151,6 +159,22 @@ void MM_DumpTables(tVAddr Start, tVAddr End)
 	const tPAddr	MASK = ~0xF98;
 	
 	Start >>= 12;	End >>= 12;
+	
+	Log("Directory Entries:");
+	for(page = Start >> 10;
+		page < (End >> 10)+1;
+		page ++)
+	{
+		if(gaPageDir[page])
+		{
+			Log(" 0x%08x-0x%08x :: 0x%08x",
+				page<<22, ((page+1)<<22)-1,
+				gaPageDir[page]&~0xFFF
+				);
+		}
+	}
+	
+	Log("Table Entries:");
 	for(page = Start, curPos = Start<<12;
 		page < End;
 		curPos += 0x1000, page++)
@@ -160,7 +184,7 @@ void MM_DumpTables(tVAddr Start, tVAddr End)
 		||  (gaPageTable[page] & MASK) != expected)
 		{
 			if(expected) {
-				Log("0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
+				Log(" 0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
 					rangeStart, curPos - 1,
 					gaPageTable[rangeStart>>12] & ~0xFFF,
 					(expected & ~0xFFF) - 1,
@@ -199,11 +223,18 @@ void MM_DumpTables(tVAddr Start, tVAddr End)
  */
 tPAddr MM_Allocate(Uint VAddr)
 {
+	tPAddr	paddr;
 	// Check if the directory is mapped
 	if( gaPageDir[ VAddr >> 22 ] == 0 )
 	{
 		// Allocate directory
-		gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3;
+		paddr = MM_AllocPhys();
+		if( paddr == 0 ) {
+			Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
+			return 0;
+		}
+		// Map
+		gaPageDir[ VAddr >> 22 ] = paddr | 3;
 		// Mark as user
 		if(VAddr < MM_USER_MAX)	gaPageDir[ VAddr >> 22 ] |= PF_USER;
 		
@@ -217,13 +248,20 @@ tPAddr MM_Allocate(Uint VAddr)
 	}
 	
 	// Allocate
-	gaPageTable[ VAddr >> 12 ] = MM_AllocPhys() | 3;
+	paddr = MM_AllocPhys();
+	if( paddr == 0 ) {
+		Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
+			VAddr, __builtin_return_address(0));
+		return 0;
+	}
+	// Map
+	gaPageTable[ VAddr >> 12 ] = paddr | 3;
 	// Mark as user
 	if(VAddr < MM_USER_MAX)	gaPageTable[ VAddr >> 12 ] |= PF_USER;
 	// Invalidate Cache for address
 	INVLPG( VAddr & ~0xFFF );
 	
-	return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
+	return paddr;
 }
 
 /**
@@ -348,10 +386,12 @@ Uint MM_ClearUser()
 		}
 		
 		MM_DerefPhys( gaPageDir[i] & ~0xFFF );
+		gaPageDir[i] = 0;
+		INVLPG( &gaPageTable[i*1024] );
 	}
+	INVLPG( gaPageDir );
 	
-	
-	return *gTmpCR3;
+	return *gaPageCR3;
 }
 
 /**
@@ -361,7 +401,8 @@ Uint MM_ClearUser()
 Uint MM_Clone()
 {
 	Uint	i, j;
-	Uint	kStackBase = gCurrentThread->KernelStack - KERNEL_STACK_SIZE;
+	Uint	page = 0;
+	Uint	kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE;
 	void	*tmp;
 	
 	//ENTER("");
@@ -378,34 +419,31 @@ Uint MM_Clone()
 		// Check if table is allocated
 		if( !(gaPageDir[i] & PF_PRESENT) ) {
 			gaTmpDir[i] = 0;
+			page += 1024;
 			continue;
 		}
 		
 		// Allocate new table
 		gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
-		INVLPG( &gaTmpTable[i*1024] );
+		INVLPG( &gaTmpTable[page] );
 		// Fill
-		for( j = 0; j < 1024; j ++ )
+		for( j = 0; j < 1024; j ++, page++ )
 		{
-			if( !(gaPageTable[i*1024+j] & PF_PRESENT) ) {
-				gaTmpTable[i*1024+j] = 0;
+			if( !(gaPageTable[page] & PF_PRESENT) ) {
+				gaTmpTable[page] = 0;
 				continue;
 			}
 			
-			#if USE_COW
 			// Refrence old page
-			MM_RefPhys( gaPageTable[i*1024+j] & ~0xFFF );
+			MM_RefPhys( gaPageTable[page] & ~0xFFF );
 			// Add to new table
-			if(gaPageTable[i*1024+j] & PF_WRITE) {
-				gaTmpTable[i*1024+j] = (gaPageTable[i*1024+j] & ~PF_WRITE) | PF_COW;
-				gaPageTable[i*1024+j] = (gaPageTable[i*1024+j] & ~PF_WRITE) | PF_COW;
+			if(gaPageTable[page] & PF_WRITE) {
+				gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
+				gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
+				INVLPG( page << 12 );
 			}
 			else
-				gaTmpTable[i*1024+j] = gaPageTable[i*1024+j];
-			LOG("gaTmpTable[0x%x] = 0x%x", i*1024+j, gaTmpTable[i*1024+j]);
-			#else
-			gaTmpTable[i*1024+j] = MM_DuplicatePage( (i*1024+j)<<12 ) | (gaPageTable[i*1024+j]&7);
-			#endif
+				gaTmpTable[page] = gaPageTable[page];
 		}
 	}
 	
@@ -606,7 +644,7 @@ Uint MM_MapTemp(tPAddr PAddr)
 			return TEMP_MAP_ADDR + (i << 12);
 		}
 		RELEASE( &gilTempMappings );
-		Proc_Yield();
+		Threads_Yield();
 	}
 }