--- /dev/null
+/*
+ * Acess2 Core
+ *
+ * include/tpl_mm_phys_bitmap.h
+ * Physical Memory Manager Template
+ */
+#define DEBUG 0
+
+/*
+ * Bitmap Edition
+ *
+ * Uses 4.125+PtrSize bytes per page
+ */
+
+#define MM_PAGE_REFCOUNTS MM_PMM_BASE
+#define MM_PAGE_NODES (MM_PMM_BASE+(MM_MAXPHYSPAGE*sizeof(Uint32)))
+#define MM_PAGE_BITMAP (MM_PAGE_NODES+(MM_MAXPHYSPAGE*sizeof(void*)))
+
+// === PROTOTYPES ===
+//void MM_InitPhys_Multiboot(tMBoot_Info *MBoot);
+//tPAddr MM_AllocPhysRange(int Num, int Bits);
+//tPAddr MM_AllocPhys(void);
+//void MM_RefPhys(tPAddr PAddr);
+//void MM_DerefPhys(tPAddr PAddr);
+ int MM_int_GetRangeID( tPAddr Addr );
+ int MM_int_GetMapEntry( void *Data, int Index, tPAddr *Start, tPAddr *Length );
+void MM_Tpl_InitPhys(int MaxRAMPage, void *MemoryMap);
+
+// === GLOBALS ===
+tMutex glPhysicalPages;
+void **gapPageNodes = (void*)MM_PAGE_NODES; //!< Associated VFS Node for each page
+Uint32 *gaiPageReferences = (void*)MM_PAGE_REFCOUNTS; // Reference Counts
+Uint32 *gaPageBitmaps = (void*)MM_PAGE_BITMAP; // Used bitmap (1 == avail)
+Uint64 giMaxPhysPage = 0; // Maximum Physical page
+ int gbPMM_Init = 0;
+ int gaiPhysRangeFirstFree[MM_NUM_RANGES];
+ int gaiPhysRangeLastFree[MM_NUM_RANGES];
+ int gaiPhysRangeNumFree[MM_NUM_RANGES];
+
+// === CODE ===
+/**
+ * \brief Initialise the physical memory manager with a passed memory map
+ */
+void MM_Tpl_InitPhys(int MaxRAMPage, void *MemoryMap)
+{
+ int mapIndex = 0;
+ tPAddr rangeStart, rangeLen;
+
+ if( MM_PAGE_BITMAP + (MM_MAXPHYSPAGE/8) > MM_PMM_END ) {
+ Log_KernelPanic("PMM", "Config Error, PMM cannot fit data in allocated range");
+ }
+
+ giMaxPhysPage = MaxRAMPage;
+
+ while( MM_int_GetMapEntry(MemoryMap, mapIndex++, &rangeStart, &rangeLen) )
+ {
+ tVAddr bitmap_page;
+ rangeStart /= PAGE_SIZE;
+ rangeLen /= PAGE_SIZE;
+
+ bitmap_page = (tVAddr)&gaPageBitmaps[rangeStart/32];
+ bitmap_page &= ~(PAGE_SIZE-1);
+
+ // Only need to allocate bitmaps
+ if( !MM_GetPhysAddr( bitmap_page ) ) {
+ if( MM_Allocate( bitmap_page ) ) {
+ Log_KernelPanic("PMM", "Out of memory during init, this is bad");
+ return ;
+ }
+ memset( (void*)bitmap_page, 0, rangeStart/8 & ~(PAGE_SIZE-1) );
+ }
+
+ // Align to 32 pages
+ for( ; (rangeStart & 31) && rangeLen > 0; rangeStart++, rangeLen-- ) {
+ gaPageBitmaps[rangeStart / 32] |= 1 << (rangeStart&31);
+ }
+ // Mark blocks of 32 as avail
+ for( ; rangeLen > 31; rangeStart += 32, rangeLen -= 32 ) {
+ gaPageBitmaps[rangeStart / 32] = -1;
+ }
+ // Mark the tail
+ for( ; rangeLen > 0; rangeStart ++, rangeLen -- ) {
+ gaPageBitmaps[rangeStart / 32] |= 1 << (rangeStart&31);
+ }
+ }
+
+ gbPMM_Init = 1;
+
+ LEAVE('-');
+}
+
+/**
+ * \brief Allocate a contiguous range of physical pages with a maximum
+ * bit size of \a MaxBits
+ * \param Pages Number of pages to allocate
+ * \param MaxBits Maximum size of the physical address
+ * \note If \a MaxBits is <= 0, any sized address is used (with preference
+ * to higher addresses)
+ */
+tPAddr MM_AllocPhysRange(int Pages, int MaxBits)
+{
+ tPAddr addr, ret;
+ int rangeID;
+ int nFree = 0, i;
+
+ ENTER("iPages iBits", Pages, MaxBits);
+
+ // Get range ID
+ if( MaxBits <= 0 || MaxBits >= 64 ) // Speedup for the common case
+ rangeID = MM_RANGE_MAX;
+ else
+ rangeID = MM_int_GetRangeID( (1LL << MaxBits) - 1 );
+
+ Mutex_Acquire(&glPhysicalPages);
+
+ // Check if the range actually has any free pages
+ while(gaiPhysRangeNumFree[rangeID] == 0 && rangeID)
+ rangeID --;
+
+ LOG("rangeID = %i", rangeID);
+
+ // Check if there is enough in the range
+ if(gaiPhysRangeNumFree[rangeID] >= Pages)
+ {
+ LOG("{%i,0x%x -> 0x%x}",
+ giPhysRangeFree[rangeID],
+ giPhysRangeFirst[rangeID], giPhysRangeLast[rangeID]
+ );
+ // Do a cheap scan, scanning upwards from the first free page in
+ // the range
+ nFree = 0;
+ addr = gaiPhysRangeFirstFree[ rangeID ];
+ while( addr <= gaiPhysRangeLastFree[ rangeID ] )
+ {
+ #if USE_SUPER_BITMAP
+ // Check the super bitmap
+ if( gaSuperBitmap[addr / (32*32)] == 0 )
+ {
+ LOG("nFree = %i = 0 (super) (0x%x)", nFree, addr);
+ nFree = 0;
+ addr += 1LL << (6+6);
+ addr &= ~0xFFF; // (1LL << 6+6) - 1
+ continue;
+ }
+ #endif
+ // Check page block (32 pages)
+ if( gaPageBitmaps[addr / 32] == 0) {
+ LOG("nFree = %i = 0 (main) (0x%x)", nFree, addr);
+ nFree = 0;
+ addr += 1LL << (6);
+ addr &= ~0x3F;
+ continue;
+ }
+ // Check individual page
+ if( !(gaPageBitmaps[addr / 32] & (1LL << (addr & 31))) )
+ {
+ LOG("nFree = %i = 0 (page) (0x%x)", nFree, addr);
+ nFree = 0;
+ addr ++;
+ continue;
+ }
+ nFree ++;
+ addr ++;
+ LOG("nFree(%i) == %i (0x%x)", nFree, Pages, addr);
+ if(nFree == Pages)
+ break;
+ }
+ LOG("nFree = %i", nFree);
+ // If we don't find a contiguous block, nFree will not be equal
+ // to Num, so we set it to zero and do the expensive lookup.
+ if(nFree != Pages) nFree = 0;
+ }
+
+ if( !nFree )
+ {
+ // Oops. ok, let's do an expensive check (scan down the list
+ // until a free range is found)
+ nFree = 1;
+ addr = gaiPhysRangeLastFree[ rangeID ];
+ // TODO
+ Mutex_Release(&glPhysicalPages);
+ // TODO: Page out
+ // ATM. Just Warning
+ Warning(" MM_AllocPhysRange: Out of memory (unable to fulfil request for %i pages)", Pages);
+ Log_Warning("PMM",
+ "Out of memory (unable to fulfil request for %i pages)",
+ Pages
+ );
+ LEAVE('i', 0);
+ return 0;
+ }
+ LOG("nFree = %i, addr = 0x%08x", nFree, addr);
+
+ // Mark pages as allocated
+ addr -= Pages;
+ for( i = 0; i < Pages; i++, addr++ )
+ {
+ // Mark as used
+ gaPageBitmaps[addr / 32] &= ~(1 << (addr & 31));
+ // Maintain first possible free
+ rangeID = MM_int_GetRangeID(addr * PAGE_SIZE);
+ gaiPhysRangeNumFree[ rangeID ] --;
+ if(addr == gaiPhysRangeFirstFree[ rangeID ])
+ gaiPhysRangeFirstFree[ rangeID ] += 1;
+
+ // Mark as referenced if the reference count page is valid
+ if(MM_GetPhysAddr( (tVAddr)&gaiPageReferences[addr] )) {
+ gaiPageReferences[addr] = 1;
+ }
+ }
+ ret = addr; // Save the return address
+
+ #if USE_SUPER_BITMAP
+ // Update super bitmap
+ Pages += addr & (32-1);
+ addr &= ~(32-1);
+ Pages = (Pages + (32-1)) & ~(32-1);
+ for( i = 0; i < Pages/32; i++ )
+ {
+ if( gaPageBitmaps[ addr / 32 ] + 1 == 0 )
+ gaSuperBitmap[addr / (32*32)] |= 1LL << ((addr / 32) & 31);
+ }
+ #endif
+
+ Mutex_Release(&glPhysicalPages);
+ LEAVE('x', ret << 12);
+ return ret << 12;
+}
+
+/**
+ * \brief Allocate a single physical page, with no preference as to address size.
+ */
+tPAddr MM_AllocPhys(void)
+{
+ int i;
+
+ if( !gbPMM_Init )
+ {
+ // Hack to allow allocation during setup
+ for(i = 0; i < NUM_STATIC_ALLOC; i++) {
+ if( gaiStaticAllocPages[i] ) {
+ tPAddr ret = gaiStaticAllocPages[i];
+ gaiStaticAllocPages[i] = 0;
+ Log("MM_AllocPhys: Return %x, static alloc %i", ret, i);
+ return ret;
+ }
+ }
+
+ tPAddr ret = 0;
+ for( ret = 0; ret < giMaxPhysPage; ret ++ )
+ {
+ if( !MM_GetPhysAddr( (tVAddr)&gaPageBitmaps[ret/32] ) ) {
+ ret += PAGE_SIZE*8;
+ continue ;
+ }
+ if( gaPageBitmaps[ret/32] == 0 ) {
+ ret += 32-1;
+ continue ;
+ }
+ if( gaPageBitmaps[ret/32] & (1 << (ret&31)) ) {
+ gaPageBitmaps[ret/32] &= ~(1 << (ret&31));
+ return ret * PAGE_SIZE;
+ }
+ }
+ Log_Error("PMM", "MM_AllocPhys failed duing init");
+ return 0;
+ }
+
+ return MM_AllocPhysRange(1, -1);
+}
+
+/**
+ * \brief Reference a physical page
+ */
+void MM_RefPhys(tPAddr PAddr)
+{
+ tPAddr page = PAddr / PAGE_SIZE;
+
+ if( page >= giMaxPhysPage ) return ;
+
+ if( gaPageBitmaps[ page / 32 ] & (1LL << (page&31)) )
+ {
+ // Allocate
+ gaPageBitmaps[page / 32] &= ~(1LL << (page&31));
+ #if USE_SUPER_BITMAP
+ if( gaPageBitmaps[page / 32] == 0 )
+ gaSuperBitmap[page / (32*32)] &= ~(1LL << ((page / 32) & 31));
+ #endif
+ }
+ else
+ {
+ tVAddr refpage = (tVAddr)&gaiPageReferences[page] & ~(PAGE_SIZE-1);
+ // Reference again
+ if( !MM_GetPhysAddr( refpage ) )
+ {
+ if( MM_Allocate(refpage) == 0 ) {
+ // Out of memory, can this be resolved?
+ // TODO: Reclaim memory
+ Log_Error("PMM", "Out of memory (MM_RefPhys)");
+ return ;
+ }
+ memset((void*)refpage, 0, PAGE_SIZE);
+ gaiPageReferences[page] = 2;
+ }
+ else
+ gaiPageReferences[ page ] ++;
+ }
+}
+
+/**
+ * \brief Dereference a physical page
+ */
+void MM_DerefPhys(tPAddr PAddr)
+{
+ Uint64 page = PAddr >> 12;
+
+ if( PAddr >> 12 > giMaxPhysPage ) return ;
+
+ if( MM_GetPhysAddr( (tVAddr)&gaiPageReferences[page] ) )
+ {
+ if( gaiPageReferences[page] > 0 )
+ gaiPageReferences[ page ] --;
+ if( gaiPageReferences[ page ] == 0 ) {
+ gaPageBitmaps[ page / 32 ] |= 1 << (page&31);
+ // TODO: Catch when all pages in this range have been dereferenced
+ }
+ }
+ else
+ gaPageBitmaps[ page / 32 ] |= 1 << (page&31);
+ // Clear node if needed
+ if( MM_GetPhysAddr( (tVAddr)&gapPageNodes[page] ) ) {
+ gapPageNodes[page] = NULL;
+ // TODO: Catch when all pages in this range are not using nodes
+ }
+
+ // Update the free counts if the page was freed
+ if( gaPageBitmaps[ page / 32 ] & (1LL << (page&31)) )
+ {
+ int rangeID;
+ rangeID = MM_int_GetRangeID( PAddr );
+ gaiPhysRangeNumFree[ rangeID ] ++;
+ if( gaiPhysRangeFirstFree[rangeID] > page )
+ gaiPhysRangeFirstFree[rangeID] = page;
+ if( gaiPhysRangeLastFree[rangeID] < page )
+ gaiPhysRangeLastFree[rangeID] = page;
+ }
+
+ #if USE_SUPER_BITMAP
+ // If the bitmap entry is not zero, set the bit free in the super bitmap
+ if(gaPageBitmaps[ page / 32 ] != 0 ) {
+ gaSuperBitmap[page / (32*32)] |= 1LL << ((page / 32) & 31);
+ }
+ #endif
+}
+
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