From: John Hodge <tpg@mutabah.net>
Date: Sun, 25 Sep 2011 03:40:07 +0000 (+0800)
Subject: Kernel - Untested template stack based PMM
X-Git-Tag: rel0.11~67
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=f4e2ddb14fa3a66332907bf7112e3cf78bf86947;p=tpg%2Facess2.git

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
index 00000000..ac543f1b
--- /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;
+}