X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86_64%2Fmm_phys.c;h=dd8ddf660f0176fec163b765874699b4d48db0f8;hb=9f407c493c33928e0f19b834699d9694036ca42e;hp=c64e1e03acea7dd0139a17039caac2d94324a7d4;hpb=33bcf4b3feb0e5e4548548bf3d2a50c52ffb6115;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86_64/mm_phys.c b/Kernel/arch/x86_64/mm_phys.c
index c64e1e03..dd8ddf66 100644
--- a/Kernel/arch/x86_64/mm_phys.c
+++ b/Kernel/arch/x86_64/mm_phys.c
@@ -4,6 +4,7 @@
  * Physical Memory Manager
  */
 #include <acess.h>
+#include <mboot.h>
 //#include <mm_phys.h>
 
 enum eMMPhys_Ranges
@@ -19,15 +20,42 @@ enum eMMPhys_Ranges
 // === GLOBALS ===
 tSpinlock	glPhysicalPages;
 Uint64	*gaSuperBitmap;	// 1 bit = 64 Pages
-Uint64	*gaPrimaryBitmap;	// 1 bit = 1 Page
+Uint64	*gaPrimaryBitmap;	// 1 bit = 64 Pages
+Uint32	*gaiPageReferences;	// Reference Counts
 tPAddr	giFirstFreePage;	// First possibly free page
 Uint64	giPhysRangeFree[NUM_MM_PHYS_RANGES];	// Number of free pages in each range
 Uint64	giPhysRangeFirst[NUM_MM_PHYS_RANGES];	// First free page in each range
 Uint64	giPhysRangeLast[NUM_MM_PHYS_RANGES];	// Last free page in each range
+Uint64	giMaxPhysPage = 0;	// Maximum Physical page
 
 // === CODE ===
-void MM_InitPhys()
+void MM_InitPhys(tMBoot_Info *MBoot)
 {
+	tMBoot_MMapEnt	*mmapStart;
+	tMBoot_MMapEnt	*ent;
+	Uint64	maxAddr = 0;
+	
+	// Scan the physical memory map
+	mmapStart = (void *)( KERNEL_BASE | MBoot->MMapAddr );
+	ent = mmapStart;
+	while( (Uint)ent < (Uint)mmapStart + MBoot->MMapLength )
+	{
+		// Adjust for the size of the entry
+		ent->Size += 4;
+		
+		// If entry is RAM and is above `maxAddr`, change `maxAddr`
+		if(ent->Type == 1 && ent->Base + ent->Length > maxAddr)
+			maxAddr = ent->Base + ent->Length;
+		// Go to next entry
+		ent = (tMBoot_MMapEnt *)( (Uint)ent + ent->Size );
+	}
+	
+	if(maxAddr == 0) {
+		giMaxPhysPage = (MBoot->HighMem >> 2) + 256;	// HighMem is a kByte value
+	}
+	else {
+		giMaxPhysPage = maxAddr >> 12;
+	}
 }
 
 /**
@@ -92,14 +120,14 @@ tPAddr MM_AllocPhysRange(int Num, int Bits)
 				continue;
 			}
 			// Check page block (64 pages)
-			if( gaPrimaryBitmap[addr >> 6] == -1) {
+			if( gaSuperBitmap[addr >> (6+6)] & (1 << (addr>>6)&63)) {
 				nFree = 0;
 				addr += 1 << (12+6);
 				addr &= (1 << (12+6)) - 1;
 				continue;
 			}
 			// Check individual page
-			if( gaPrimaryBitmap[addr >> 6] & (1 << (addr&63)) ) {
+			if( gaiPageReferences[addr] ) {
 				nFree = 0;
 				addr ++;
 				continue;
@@ -134,6 +162,7 @@ tPAddr MM_AllocPhysRange(int Num, int Bits)
 	addr -= Num;
 	for( i = 0; i < Num; i++ )
 	{
+		gaiPageReferences[addr] = 1;
 		gaPrimaryBitmap[addr>>6] |= 1 << (addr & 63);
 		if( gaPrimaryBitmap[addr>>6] == -1 )
 			gaSuperBitmap[addr>>12] |= 1 << ((addr >> 6) & 64);
@@ -158,3 +187,30 @@ tPAddr MM_AllocPhys(void)
 {
 	return MM_AllocPhysRange(1, -1);
 }
+
+/**
+ * \brief Reference a physical page
+ */
+void MM_RefPhys(tPAddr PAddr)
+{
+	if( PAddr >> 12 > giMaxPhysPage )	return ;
+	gaiPageReferences[ PAddr >> 12 ] ++;
+	
+	gaPrimaryBitmap[PAddr >> 18] |= 1 << ((PAddr>>12) & 63);
+	if( gaPrimaryBitmap[PAddr >> 18] == -1 )
+		gaSuperBitmap[PAddr >> 24] |= 1 << ((PAddr >> 18) & 64);
+}
+
+/**
+ * \brief Dereference a physical page
+ */
+void MM_DerefPhys(tPAddr PAddr)
+{
+	if( PAddr >> 12 > giMaxPhysPage )	return ;
+	gaiPageReferences[ PAddr >> 12 ] --;
+	if( gaiPageReferences[ PAddr >> 12 ] )
+	{
+		gaPrimaryBitmap[PAddr >> 18] &= ~(1 << ((PAddr >> 12) & 63));
+		gaSuperBitmap[PAddr >> 24] &= ~(1 << ((PAddr >> 18) & 64));
+	}
+}