Kernel - Untested template stack based PMM

diff --git a/Kernel/include/tpl_mm_phys_stack.h b/Kernel/include/tpl_mm_phys_stack.h
new file mode 100644 (file)
index 0000000..ac543f1
--- /dev/null
+++ b/Kernel/include/tpl_mm_phys_stack.h
@@ -0,0 +1,322 @@
+/*
+ * Acess2 Core
+ * 
+ * include/tpl_mm_phys.h
+ * Physical Memory Manager Template
+ */
+#define DEBUG  0
+
+/**
+ * \file tpl_mm_phys.h
+ * \brief Template physical memory manager
+ *
+ * An extensible physical memory manager
+ *
+ * Usage: Requires NUM_MM_PHYS_RANGES to be set to the number of address
+ * "classes" wanted.
+ * MAX_PHYS_PAGES - Used to calculate structure sizes
+ * PADDR_TYPE
+ */
+
+// === 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_IsPhysUnavail( tPageNum Page );
+
+// === GLOBALS ===
+tMutex glPhysicalPages;
+//Uint64       *gaPageStacks[NUM_MM_PHYS_RANGES];      // Page stacks
+ int   giPageStackSizes[NUM_MM_PHYS_RANGES];   // Points to the first unused slot
+Uint32 *gaiPageReferences = (void*)MM_PAGE_COUNTS;     // Reference Counts
+Uint64 giMaxPhysPage = 0;      // Maximum Physical page
+
+// === CODE ===
+/**
+ * \brief Initialise the physical memory map using a Multiboot 1 map
+ */
+void MM_Tpl_InitPhys(int MaxRAMPage)
+{
+       const int       PAGE_SIZE = 0x1000;
+       const int       pagesPerPageOnStack = PAGE_SIZE / sizeof(gaPageStack[0]);
+        int    i;
+       tPageNum        page;
+
+//     ENTER("pMBoot=%p", MBoot);
+       
+       giMaxPhysPage = MaxRAMPage;
+       
+       tPAddr  page = 0;
+       for( i = 0; i < NUM_MM_PHYS_RANGES; i ++ )
+       {
+               for( ; page < giPageRangeMax[i] && page < giMaxPhysPage; page ++ )
+               {
+                        int    rangeSize;
+
+                       rangeSize = MM_int_IsPhysUnavail(page);
+                       if( rangeSize > 0 ) {
+                               page += rangeSize;
+                               continue;
+                       }
+                       // Page is avaliable for use
+       
+                       // Check if the page stack is allocated
+                       tVAddr  stack_page = &gaPageStacks[i][giPageStackSizes[i]&~pagesPerPageOnStack];
+                       if( !MM_GetPhysAddr( stack_page ) ) {
+                               MM_Map( stack_page, page*PAGE_SIZE );
+                       }
+                       else {
+                               gaPageStacks[i][ giPageStackSizes[i] ] = page;
+                               giPageStackSizes[i] ++;
+                       }
+               }
+       }
+       
+       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);
+       
+       if( MaxBits <= 0 || MaxBits >= 64 )     // Speedup for the common case
+               rangeID = MM_PHYS_MAX;
+       else
+               rangeID = MM_int_GetRangeID( (1LL << MaxBits) - 1 );
+       
+       LOG("rangeID = %i", rangeID);
+       
+       Mutex_Acquire(&glPhysicalPages);
+       
+       // Check if the range actually has any free pages
+       while(giPageStackSizes[rangeID] == 0 && rangeID)
+               rangeID --;
+       
+       LOG("rangeID = %i", rangeID);
+       
+       // What the? Oh, man. No free pages
+       if(giPageStackSizes[rangeID] == 0) {
+               Mutex_Release(&glPhysicalPages);
+               // TODO: Page out / attack the cache
+               // ATM. Just Warning
+               Warning(" MM_AllocPhysRange: Out of free pages");
+               Log_Warning("Arch",
+                       "Out of memory (unable to fulfil request for %i pages), zero remaining",
+                       Pages
+                       );
+               LEAVE('i', 0);
+               return 0;
+       }
+       
+       // Check if there is enough in the range
+       if(giPhysRangeFree[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 = giPhysRangeFirst[ rangeID ];
+               while( addr <= giPhysRangeLast[ rangeID ] )
+               {
+                       //Log(" MM_AllocPhysRange: addr = 0x%x", addr);
+                       // Check the super bitmap
+                       if( gaSuperBitmap[addr >> (6+6)] + 1 == 0 ) {
+                               LOG("nFree = %i = 0 (super) (0x%x)", nFree, addr);
+                               nFree = 0;
+                               addr += 1LL << (6+6);
+                               addr &= ~0xFFF; // (1LL << 6+6) - 1
+                               continue;
+                       }
+                       // Check page block (64 pages)
+                       if( gaMainBitmap[addr >> 6] + 1 == 0) {
+                               LOG("nFree = %i = 0 (main) (0x%x)", nFree, addr);
+                               nFree = 0;
+                               addr += 1LL << (6);
+                               addr &= ~0x3F;
+                               continue;
+                       }
+                       // Check individual page
+                       if( gaMainBitmap[addr >> 6] & (1LL << (addr & 63)) ) {
+                               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 = giPhysRangeLast[ 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("Arch",
+                       "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++ )
+       {
+               gaMainBitmap[addr >> 6] |= 1LL << (addr & 63);
+               rangeID = MM_int_GetRangeID(addr << 12);
+               giPhysRangeFree[ rangeID ] --;
+               LOG("%x == %x", addr, giPhysRangeFirst[ rangeID ]);
+               if(addr == giPhysRangeFirst[ rangeID ])
+                       giPhysRangeFirst[ rangeID ] += 1;
+       }
+       ret = addr;     // Save the return address
+       
+       // Update super bitmap
+       Pages += addr & (64-1);
+       addr &= ~(64-1);
+       Pages = (Pages + (64-1)) & ~(64-1);
+       for( i = 0; i < Pages/64; i++ )
+       {
+               if( gaMainBitmap[ addr >> 6 ] + 1 == 0 )
+                       gaSuperBitmap[addr>>12] |= 1LL << ((addr >> 6) & 63);
+       }
+       
+       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;
+       
+       // 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;
+               }
+       }
+       
+       return MM_AllocPhysRange(1, -1);
+}
+
+/**
+ * \brief Reference a physical page
+ */
+void MM_RefPhys(tPAddr PAddr)
+{
+       Uint64  page = PAddr >> 12;
+       
+       if( PAddr >> 12 > giMaxPhysPage )       return ;
+       
+       if( gaMainBitmap[ page >> 6 ] & (1LL << (page&63)) )
+       {
+               // Reference again
+               gaMultiBitmap[ page >> 6 ] |= 1LL << (page&63);
+               gaiPageReferences[ page ] ++;
+       }
+       else
+       {
+               // Allocate
+               gaMainBitmap[page >> 6] |= 1LL << (page&63);
+               if( gaMainBitmap[page >> 6 ] + 1 == 0 )
+                       gaSuperBitmap[page>> 12] |= 1LL << ((page >> 6) & 63);
+       }
+}
+
+/**
+ * \brief Dereference a physical page
+ */
+void MM_DerefPhys(tPAddr PAddr)
+{
+       Uint64  page = PAddr >> 12;
+       
+       if( PAddr >> 12 > giMaxPhysPage )       return ;
+       
+       if( gaMultiBitmap[ page >> 6 ] & (1LL << (page&63)) ) {
+               gaiPageReferences[ page ] --;
+               if( gaiPageReferences[ page ] == 1 )
+                       gaMultiBitmap[ page >> 6 ] &= ~(1LL << (page&63));
+               if( gaiPageReferences[ page ] == 0 )
+                       gaMainBitmap[ page >> 6 ] &= ~(1LL << (page&63));
+       }
+       else
+               gaMainBitmap[ page >> 6 ] &= ~(1LL << (page&63));
+       
+       // Update the free counts if the page was freed
+       if( !(gaMainBitmap[ page >> 6 ] & (1LL << (page&63))) )
+       {
+                int    rangeID;
+               rangeID = MM_int_GetRangeID( PAddr );
+               giPhysRangeFree[ rangeID ] ++;
+               if( giPhysRangeFirst[rangeID] > page )
+                       giPhysRangeFirst[rangeID] = page;
+               if( giPhysRangeLast[rangeID] < page )
+                       giPhysRangeLast[rangeID] = page;
+       }
+       
+       // If the bitmap entry is not -1, unset the bit in the super bitmap
+       if(gaMainBitmap[ page >> 6 ] + 1 != 0 ) {
+               gaSuperBitmap[page >> 12] &= ~(1LL << ((page >> 6) & 63));
+       }
+}
+
+/**
+ * \brief Takes a physical address and returns the ID of its range
+ * \param Addr Physical address of page
+ * \return Range ID from eMMPhys_Ranges
+ */
+int MM_int_GetRangeID( tPAddr Addr )
+{
+       if(Addr >> 32)
+               return MM_PHYS_MAX;
+       else if(Addr >> 24)
+               return MM_PHYS_32BIT;
+       else if(Addr >> 20)
+               return MM_PHYS_24BIT;
+       else if(Addr >> 16)
+               return MM_PHYS_20BIT;
+       else
+               return MM_PHYS_16BIT;
+}