Kernel - Reworked x86 physical memory allocation

- Turned reference count array into a page info array
- Allocated when needed as opposed to at boot
- TODO: Split it up into two arrays instead, to save space
 > Could also have a MM_AllocPhys variant that picks pages from allocated
   info blocks instead of just the first avaliable

diff --git a/Kernel/Makefile b/Kernel/Makefile
index 65527f6..8818890 100644 (file)
--- a/Kernel/Makefile
+++ b/Kernel/Makefile
@@ -38,7 +38,7 @@ OBJ += drv/vterm.o drv/proc.o drv/fifo.o drv/iocache.o drv/pci.o
 #OBJ += drv/kb.o drv/dma.o drv/vga.o
 OBJ += binary.o bin/elf.o bin/pe.o
 OBJ += vfs/main.o vfs/open.o vfs/acls.o vfs/dir.o vfs/io.o vfs/mount.o
-OBJ += vfs/memfile.o vfs/nodecache.o vfs/handle.o vfs/select.o
+OBJ += vfs/memfile.o vfs/nodecache.o vfs/handle.o vfs/select.o vfs/mmap.o
 OBJ += vfs/fs/root.o vfs/fs/devfs.o
 OBJ += $(addprefix drv/, $(addsuffix .o,$(DRIVERS)))
 OBJ := $(addsuffix .$(ARCH), $(OBJ))

diff --git a/Kernel/arch/x86/include/mm_virt.h b/Kernel/arch/x86/include/mm_virt.h
index e19a310..a3cae12 100644 (file)
--- a/Kernel/arch/x86/include/mm_virt.h
+++ b/Kernel/arch/x86/include/mm_virt.h
@@ -22,7 +22,12 @@
 #define MM_KERNEL_VFS  0xCF000000      // 
 #define MM_KUSER_CODE  0xCFFF0000      // 16 Pages
 #define        MM_MODULE_MIN   0xD0000000      // Lowest Module Address
-#define MM_MODULE_MAX  0xF0000000      // 512 MiB
+#define MM_MODULE_MAX  0xE0000000      // 128 MiB
+// Needs (2^36/2^12*8 bytes)
+// - 2^27 bytes max = 128 MiB = 0x10000000
+// 2^12/2^3 items per page
+// - 2^9 = 512
+#define        MM_PAGEINFO_BASE        0xE0000000
 
 // === FUNCTIONS ===
 extern void    MM_FinishVirtualInit(void);

diff --git a/Kernel/arch/x86/mm_phys.c b/Kernel/arch/x86/mm_phys.c
index d051adb..b5031b3 100644 (file)
--- a/Kernel/arch/x86/mm_phys.c
+++ b/Kernel/arch/x86/mm_phys.c
@@ -10,7 +10,6 @@
 //#define USE_STACK    1
 #define TRACE_ALLOCS   0       // Print trace messages on AllocPhys/DerefPhys
 
-#define        REFERENCE_BASE  0xE0400000
 
 // === IMPORTS ===
 extern void    gKernelEnd;
@@ -31,7 +30,12 @@ Uint64       giLastPossibleFree = 0; // Last possible free page (before all pages are
 
 Uint32 gaSuperBitmap[1024];    // Blocks of 1024 Pages
 Uint32 gaPageBitmap[1024*1024/32];     // Individual pages
-Uint32 *gaPageReferences;
+struct sPageInfo {
+        int    ReferenceCount;
+       void    *Node;
+       Uint64  Offset;
+}      *gaPageInfo;
+#define INFO_PER_PAGE  (0x1000/sizeof(gaPageInfo[0]))
 
 // === CODE ===
 void MM_Install(tMBoot_Info *MBoot)
@@ -104,26 +108,10 @@ void MM_Install(tMBoot_Info *MBoot)
                while(num--)
                        MM_RefPhys( (mods[i].Start & ~0xFFF) + (num<<12) );
        }
-       
-       // Allocate References
-       //LOG("Reference Pages %i", (giPageCount*4+0xFFF)>>12);
-       for(num = 0; num < (giPageCount*4+0xFFF)>>12; num++)
-       {
-               if( !MM_Allocate( REFERENCE_BASE + (num<<12) ) )
-               {
-                       Panic("Oh, ****, no space for the reference pages, that's bad");
-                       for(;;);
-               }
-       }
-       
-       //LOG("Filling");
-       // Fill references
-       gaPageReferences = (void*)REFERENCE_BASE;
-       memsetd(gaPageReferences, 1, kernelPages);
-       for( num = kernelPages; num < giPageCount; num++ )
-       {
-               gaPageReferences[num] = (gaPageBitmap[ num / 32 ] >> (num&31)) & 1;
-       }
+
+       gaPageInfo = (void*)MM_PAGEINFO_BASE;
+
+       Log_Log("PMem", "Physical memory set up");
 }
 
 /**
@@ -149,7 +137,6 @@ tPAddr MM_AllocPhys(void)
         int    first, last;
        for( i = numAddrClasses; i -- > 1; )
        {
-//             Log("Scanning %i (%i bits)", i, addrClasses[i]);
                first = 1 << (addrClasses[i-1] - 12);
                last = (1 << (addrClasses[i] - 12)) - 1;
                // Range is above the last free page
@@ -159,11 +146,9 @@ tPAddr MM_AllocPhys(void)
                if( last > giLastPossibleFree )
                        last = giLastPossibleFree;
                        
-//             Log(" first=%i,max=%i", first, last);
                // Scan the range
                for( indx = first; indx < last; )
                {
-//                     Log("indx = %i (< %i?)", indx, last);
                        if( gaSuperBitmap[indx>>10] == -1 ) {
                                indx += 1024;
                                continue;
@@ -186,7 +171,6 @@ tPAddr MM_AllocPhys(void)
        }
        // Out of memory?
        if( i <= 1 )    indx = -1;
-//     Log("indx = %i", indx);
        }
        #elif 0
        // Find free page
@@ -256,8 +240,8 @@ tPAddr MM_AllocPhys(void)
        }
        
        // Mark page used
-       if(gaPageReferences)
-               gaPageReferences[ indx ] = 1;
+       if( MM_GetPhysAddr( (tVAddr)&gaPageInfo[indx] ) )
+               gaPageInfo[ indx ].ReferenceCount = 1;
        gaPageBitmap[ indx>>5 ] |= 1 << (indx&31);
        
        giPhysAlloc ++;
@@ -389,8 +373,8 @@ tPAddr MM_AllocPhysRange(int Pages, int MaxBits)
        // Mark pages used
        for( i = 0; i < Pages; i++ )
        {
-               if(gaPageReferences)
-                       gaPageReferences[idx*32+sidx] = 1;
+               if( MM_GetPhysAddr( (tVAddr)&gaPageInfo[idx*32+sidx] ) )
+                       gaPageInfo[idx*32+sidx].ReferenceCount = 1;
                gaPageBitmap[ idx ] |= 1 << sidx;
                sidx ++;
                giPhysAlloc ++;
@@ -421,7 +405,7 @@ void MM_RefPhys(tPAddr PAddr)
 {
        // Get page number
        PAddr >>= 12;
-       
+
        // We don't care about non-ram pages
        if(PAddr >= giPageCount)        return;
        
@@ -429,8 +413,20 @@ void MM_RefPhys(tPAddr PAddr)
        Mutex_Acquire( &glPhysAlloc );
        
        // Reference the page
-       if(gaPageReferences)
-               gaPageReferences[ PAddr ] ++;
+       if( gaPageInfo )
+       {
+               if( MM_GetPhysAddr( (tVAddr)&gaPageInfo[PAddr] ) == 0 ) {
+                       tVAddr  addr = ((tVAddr)&gaPageInfo[PAddr]) & ~0xFFF;
+                       Log_Debug("PMem", "MM_RefPhys: Info not allocated %llx", PAddr);
+                       Mutex_Release( &glPhysAlloc );
+                       if( MM_Allocate( addr ) == 0 ) {
+                               Log_KernelPanic("PMem", "MM_RefPhys: Out of physical memory");
+                       }
+                       Mutex_Acquire( &glPhysAlloc );
+                       memset( (void*)addr, 0, 0x1000 );
+               }
+               gaPageInfo[ PAddr ].ReferenceCount ++;
+       }
        
        // Mark as used
        gaPageBitmap[ PAddr / 32 ] |= 1 << (PAddr&31);
@@ -456,8 +452,8 @@ void MM_DerefPhys(tPAddr PAddr)
        if(PAddr >= giPageCount)        return;
        
        // Check if it is freed
-       if(gaPageReferences[ PAddr ] == 0) {
-               Warning("MM_DerefPhys - Non-referenced memory dereferenced");
+       if( !(gaPageBitmap[PAddr / 32] & (1 << PAddr%32)) ) {
+               Log_Warning("MMVirt", "MM_DerefPhys - Non-referenced memory dereferenced");
                return;
        }
        
@@ -468,10 +464,7 @@ void MM_DerefPhys(tPAddr PAddr)
                giLastPossibleFree = PAddr;
 
        // Dereference
-       gaPageReferences[ PAddr ] --;
-       
-       // Mark as free in bitmaps
-       if( gaPageReferences[ PAddr ] == 0 )
+       if( !MM_GetPhysAddr( (tVAddr)&gaPageInfo[PAddr] ) || (-- gaPageInfo[PAddr].ReferenceCount) == 0 )
        {
                #if TRACE_ALLOCS
                Log_Debug("PMem", "MM_DerefPhys: Free'd 0x%x (%i free)", PAddr, giPageCount-giPhysAlloc);
@@ -479,7 +472,7 @@ void MM_DerefPhys(tPAddr PAddr)
                //LOG("Freed 0x%x by %p\n", PAddr<<12, __builtin_return_address(0));
                giPhysAlloc --;
                gaPageBitmap[ PAddr / 32 ] &= ~(1 << (PAddr&31));
-               if(gaPageReferences[ PAddr ] == 0)
+               if(gaPageBitmap[ PAddr / 32 ] == 0)
                        gaSuperBitmap[ PAddr >> 10 ] &= ~(1 << ((PAddr >> 5)&31));
        }
        
@@ -497,7 +490,62 @@ int MM_GetRefCount(tPAddr PAddr)
        
        // We don't care about non-ram pages
        if(PAddr >= giPageCount)        return -1;
+
+       if( MM_GetPhysAddr( (tVAddr)&gaPageInfo[PAddr] ) == 0 )
+               return (gaPageBitmap[PAddr / 32] & (1 << PAddr%32)) ? 1 : 0;
        
        // Check if it is freed
-       return gaPageReferences[ PAddr ];
+       return gaPageInfo[ PAddr ].ReferenceCount;
+}
+
+/**
+ * \brief Sets the node and offset associated with a page
+ */
+int MM_SetPageInfo(tPAddr PAddr, void *Node, Uint64 Offset)
+{
+       PAddr >>= 12;
+
+       // Page doesn't exist
+       if( !(gaPageBitmap[PAddr / 32] & (1 << PAddr%32)) )
+               return 1;
+       // Allocate info block
+       if( MM_GetPhysAddr( (tVAddr)&gaPageInfo[PAddr] ) == 0 )
+       {
+               tVAddr  addr = ((tVAddr)&gaPageInfo[PAddr]) & ~0xFFF;
+               Log_Debug("PMem", "MM_SetPageInfo: Info not allocated %llx", PAddr);
+               if( MM_Allocate( addr ) == 0 ) {
+                       Log_KernelPanic("PMem", "MM_SetPageInfo: Out of physical memory");
+               }
+               memset( (void*)addr, 0, 0x1000);
+       }
+
+       gaPageInfo[ PAddr ].Node = Node;
+       gaPageInfo[ PAddr ].Offset = Offset;
+
+       return 0;
+}
+
+/**
+ * \brief Gets the Node/Offset of a page
+ */
+int MM_GetPageInfo(tPAddr PAddr, void **Node, Uint64 *Offset)
+{
+       PAddr >>= 12;
+
+       // Page doesn't exist
+       if( !(gaPageBitmap[PAddr / 32] & (1 << PAddr%32)) )
+               return 1;
+       // Info is zero if block is not allocated
+       if( MM_GetPhysAddr( (tVAddr)&gaPageInfo[PAddr] ) == 0 )
+       {
+               if(Node)        *Node = NULL;
+               if(Offset)      *Offset = 0;
+       }
+       else
+       {
+               if(Node)        *Node = gaPageInfo[ PAddr ].Node;
+               if(Offset)      *Offset = gaPageInfo[ PAddr ].Offset;
+       }
+
+       return 0;
 }

diff --git a/Kernel/include/acess.h b/Kernel/include/acess.h
index 545ecb1..707ad7f 100644 (file)
--- a/Kernel/include/acess.h
+++ b/Kernel/include/acess.h
@@ -276,6 +276,26 @@ extern void        MM_DerefPhys(tPAddr PAddr);
  * \return Reference count for the page
  */
 extern int     MM_GetRefCount(tPAddr PAddr);
+/**
+ * \brief Set the node/offset associated with a page
+ * \param PAddr        Physical address of page
+ * \param Node Node pointer (tVFS_Node)
+ * \param Offset       File offset
+ * \return Boolean failure
+ * \retval 0   Success
+ * \retval 1   Page not allocated
+ */
+extern int     MM_SetPageInfo(tPAddr PAddr, void *Node, Uint64 Offset);
+/**
+ * \brief Get the node/offset associated with a page
+ * \param PAddr        Physical address of page
+ * \param Node Node pointer (tVFS_Node) destination
+ * \param Offset       File offset destination (pointer)
+ * \return Boolean failure
+ * \retval 0   Success
+ * \retval 1   Page not allocated
+ */
+extern int     MM_GetPageInfo(tPAddr PAddr, void **Node, Uint64 *Offset);
 /**
  * \}
  */