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iokit/Kernel/IOMemoryDescriptor.cpp xnu-124.13 xnu-1228
--- xnu/xnu-124.13/iokit/Kernel/IOMemoryDescriptor.cpp
+++ xnu/xnu-1228/iokit/Kernel/IOMemoryDescriptor.cpp
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1998-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved. 
@@ -25,44 +31,295 @@
  * HISTORY
  *
  */
+// 45678901234567890123456789012345678901234567890123456789012345678901234567890
+#include <sys/cdefs.h>
 
 #include <IOKit/assert.h>
 #include <IOKit/system.h>
 #include <IOKit/IOLib.h>
 #include <IOKit/IOMemoryDescriptor.h>
+#include <IOKit/IOMapper.h>
+#include <IOKit/IOKitKeysPrivate.h>
 
 #include <IOKit/IOKitDebug.h>
+#include <libkern/OSDebug.h>
+
+#include "IOKitKernelInternal.h"
+#include "IOCopyMapper.h"
 
 #include <libkern/c++/OSContainers.h>
-#include <sys/cdefs.h>
+#include <libkern/c++/OSDictionary.h>
+#include <libkern/c++/OSArray.h>
+#include <libkern/c++/OSSymbol.h>
+#include <libkern/c++/OSNumber.h>
+
+#include <sys/uio.h>
 
 __BEGIN_DECLS
 #include <vm/pmap.h>
-void pmap_enter(pmap_t pmap, vm_offset_t va, vm_offset_t pa,
-                vm_prot_t prot, boolean_t wired);
+#include <vm/vm_pageout.h>
+#include <mach/memory_object_types.h>
+#include <device/device_port.h>
+
+#include <mach/vm_prot.h>
+#include <mach/mach_vm.h>
+#include <vm/vm_fault.h>
+#include <vm/vm_protos.h>
+
+extern ppnum_t pmap_find_phys(pmap_t pmap, addr64_t va);
 void ipc_port_release_send(ipc_port_t port);
-vm_offset_t vm_map_get_phys_page(vm_map_t map, vm_offset_t offset);
+
+/* Copy between a physical page and a virtual address in the given vm_map */
+kern_return_t copypv(addr64_t source, addr64_t sink, unsigned int size, int which);
+
+memory_object_t
+device_pager_setup(
+	memory_object_t	pager,
+	int		device_handle,
+	vm_size_t	size,
+	int		flags);
+void
+device_pager_deallocate(
+        memory_object_t);
+kern_return_t
+device_pager_populate_object(
+	memory_object_t		pager,
+	vm_object_offset_t	offset,
+	ppnum_t			phys_addr,
+	vm_size_t		size);
+kern_return_t
+memory_object_iopl_request(
+	ipc_port_t		port,
+	memory_object_offset_t	offset,
+	vm_size_t		*upl_size,
+	upl_t			*upl_ptr,
+	upl_page_info_array_t	user_page_list,
+	unsigned int		*page_list_count,
+	int			*flags);
+
+unsigned int  IOTranslateCacheBits(struct phys_entry *pp);
+
 __END_DECLS
 
+#define kIOMaximumMappedIOByteCount	(512*1024*1024)
+
+static IOMapper * gIOSystemMapper = NULL;
+
+IOCopyMapper *	  gIOCopyMapper = NULL;
+
+static ppnum_t	  gIOMaximumMappedIOPageCount = atop_32(kIOMaximumMappedIOByteCount);
+
+ppnum_t		  gIOLastPage;
+
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-OSDefineMetaClass( IOMemoryDescriptor, OSObject )
-OSDefineAbstractStructors( IOMemoryDescriptor, OSObject )
+OSDefineMetaClassAndAbstractStructors( IOMemoryDescriptor, OSObject )
 
 #define super IOMemoryDescriptor
 
 OSDefineMetaClassAndStructors(IOGeneralMemoryDescriptor, IOMemoryDescriptor)
 
-extern "C" vm_map_t IOPageableMapForAddress( vm_address_t address );
-
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-inline vm_map_t IOGeneralMemoryDescriptor::getMapForTask( task_t task, vm_address_t address )
-{
-    if( (task == kernel_task) && (kIOMemoryRequiresWire & _flags))
-        return( IOPageableMapForAddress( address ) );
+static IORecursiveLock * gIOMemoryLock;
+
+#define LOCK	IORecursiveLockLock( gIOMemoryLock)
+#define UNLOCK	IORecursiveLockUnlock( gIOMemoryLock)
+#define SLEEP	IORecursiveLockSleep( gIOMemoryLock, (void *)this, THREAD_UNINT)
+#define WAKEUP	\
+    IORecursiveLockWakeup( gIOMemoryLock, (void *)this, /* one-thread */ false)
+
+#if 0
+#define DEBG(fmt, args...)  	{ kprintf(fmt, ## args); }
+#else
+#define DEBG(fmt, args...)  	{}
+#endif
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+class _IOMemoryMap : public IOMemoryMap
+{
+    OSDeclareDefaultStructors(_IOMemoryMap)
+public:
+    IOMemoryDescriptor * fMemory;
+    IOMemoryMap *	 fSuperMap;
+    mach_vm_size_t	 fOffset;
+    mach_vm_address_t	 fAddress;
+    mach_vm_size_t	 fLength;
+    task_t		 fAddressTask;
+    vm_map_t		 fAddressMap;
+    IOOptionBits	 fOptions;
+    upl_t		 fRedirUPL;
+    ipc_port_t		 fRedirEntry;
+    IOMemoryDescriptor * fOwner;
+
+protected:
+    virtual void taggedRelease(const void *tag = 0) const;
+    virtual void free();
+
+public:
+
+    // IOMemoryMap methods
+    virtual IOVirtualAddress 	getVirtualAddress();
+    virtual IOByteCount 	getLength();
+    virtual task_t		getAddressTask();
+    virtual mach_vm_address_t 	getAddress();
+    virtual mach_vm_size_t 	getSize();
+    virtual IOMemoryDescriptor * getMemoryDescriptor();
+    virtual IOOptionBits 	getMapOptions();
+
+    virtual IOReturn 		unmap();
+    virtual void 		taskDied();
+
+    virtual IOReturn		redirect(IOMemoryDescriptor * newBackingMemory,
+					 IOOptionBits         options,
+					 IOByteCount          offset = 0);
+
+    virtual IOReturn		redirect(IOMemoryDescriptor * newBackingMemory,
+					 IOOptionBits         options,
+					 mach_vm_size_t       offset = 0);
+
+    virtual IOPhysicalAddress 	getPhysicalSegment(IOByteCount offset,
+	       					   IOByteCount * length);
+
+    // for IOMemoryDescriptor use
+    _IOMemoryMap * copyCompatible( _IOMemoryMap * newMapping );
+
+    bool init(
+	task_t			intoTask,
+	mach_vm_address_t	toAddress,
+	IOOptionBits		options,
+        mach_vm_size_t		offset,
+        mach_vm_size_t		length );
+
+    bool    setMemoryDescriptor(IOMemoryDescriptor * _memory, mach_vm_size_t _offset);
+
+    IOReturn redirect(
+	task_t			intoTask, bool redirect );
+};
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+// Some data structures and accessor macros used by the initWithOptions
+// Function
+
+enum ioPLBlockFlags {
+    kIOPLOnDevice  = 0x00000001,
+    kIOPLExternUPL = 0x00000002,
+};
+
+struct typePersMDData
+{
+    const IOGeneralMemoryDescriptor *fMD;
+    ipc_port_t fMemEntry;
+};
+
+struct ioPLBlock {
+    upl_t fIOPL;
+    vm_address_t fIOMDOffset;	// The offset of this iopl in descriptor
+    vm_offset_t fPageInfo;	// Pointer to page list or index into it
+    ppnum_t fMappedBase;	// Page number of first page in this iopl
+    unsigned int fPageOffset;	// Offset within first page of iopl
+    unsigned int fFlags;	// Flags
+};
+
+struct ioGMDData {
+    IOMapper *fMapper;
+    unsigned int fPageCnt;
+    upl_page_info_t fPageList[];
+    ioPLBlock fBlocks[];
+};
+
+#define getDataP(osd)	((ioGMDData *) (osd)->getBytesNoCopy())
+#define getIOPLList(d)	((ioPLBlock *) &(d->fPageList[d->fPageCnt]))
+#define getNumIOPL(osd, d)	\
+    (((osd)->getLength() - ((char *) getIOPLList(d) - (char *) d)) / sizeof(ioPLBlock))
+#define getPageList(d)	(&(d->fPageList[0]))
+#define computeDataSize(p, u) \
+    (sizeof(ioGMDData) + p * sizeof(upl_page_info_t) + u * sizeof(ioPLBlock))
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define next_page(a) ( trunc_page_32(a) + PAGE_SIZE )
+
+
+extern "C" {
+
+kern_return_t device_data_action(
+               int                     device_handle, 
+               ipc_port_t              device_pager,
+               vm_prot_t               protection, 
+               vm_object_offset_t      offset, 
+               vm_size_t               size)
+{
+    struct ExpansionData {
+        void *				devicePager;
+        unsigned int			pagerContig:1;
+        unsigned int			unused:31;
+	IOMemoryDescriptor *		memory;
+    };
+    kern_return_t	 kr;
+    ExpansionData *      ref = (ExpansionData *) device_handle;
+    IOMemoryDescriptor * memDesc;
+
+    LOCK;
+    memDesc = ref->memory;
+    if( memDesc)
+    {
+	memDesc->retain();
+	kr = memDesc->handleFault( device_pager, 0, 0,
+                offset, size, kIOMapDefaultCache /*?*/);
+	memDesc->release();
+    }
     else
-        return( get_task_map( task ));
+	kr = KERN_ABORTED;
+    UNLOCK;
+
+    return( kr );
+}
+
+kern_return_t device_close(
+               int     device_handle)
+{
+    struct ExpansionData {
+        void *				devicePager;
+        unsigned int			pagerContig:1;
+        unsigned int			unused:31;
+	IOMemoryDescriptor *		memory;
+    };
+    ExpansionData *   ref = (ExpansionData *) device_handle;
+
+    IODelete( ref, ExpansionData, 1 );
+
+    return( kIOReturnSuccess );
+}
+};	// end extern "C"
+
+// Note this inline function uses C++ reference arguments to return values
+// This means that pointers are not passed and NULLs don't have to be
+// checked for as a NULL reference is illegal.
+static inline void
+getAddrLenForInd(user_addr_t &addr, IOPhysicalLength &len, // Output variables
+     UInt32 type, IOGeneralMemoryDescriptor::Ranges r, UInt32 ind)
+{
+    assert(kIOMemoryTypeUIO       == type
+	|| kIOMemoryTypeVirtual   == type || kIOMemoryTypeVirtual64 == type
+	|| kIOMemoryTypePhysical  == type || kIOMemoryTypePhysical64 == type);
+    if (kIOMemoryTypeUIO == type) {
+	user_size_t us;
+	uio_getiov((uio_t) r.uio, ind, &addr, &us); len = us;
+    }
+    else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type)) {
+	IOAddressRange cur = r.v64[ind];
+	addr = cur.address;
+	len  = cur.length;
+    }
+    else {
+	IOVirtualRange cur = r.v[ind];
+	addr = cur.address;
+	len  = cur.length;
+    }
 }
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
@@ -76,30 +333,32 @@
  */
 IOMemoryDescriptor *
 IOMemoryDescriptor::withAddress(void *      address,
-                                IOByteCount   withLength,
-                                IODirection withDirection)
-{
+                                IOByteCount   length,
+                                IODirection direction)
+{
+    return IOMemoryDescriptor::
+        withAddress((vm_address_t) address, length, direction, kernel_task);
+}
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withAddress(vm_address_t address,
+                                IOByteCount  length,
+                                IODirection  direction,
+                                task_t       task)
+{
+#if TEST_V64
+    if (task)
+    {
+	IOOptionBits options = (IOOptionBits) direction;
+	if (task == kernel_task)
+	    options |= kIOMemoryAutoPrepare;
+	return (IOMemoryDescriptor::withAddressRange(address, length, options, task));
+    }
+#endif
     IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
     if (that)
     {
-	if (that->initWithAddress(address, withLength, withDirection))
-	    return that;
-
-        that->release();
-    }
-    return 0;
-}
-
-IOMemoryDescriptor *
-IOMemoryDescriptor::withAddress(vm_address_t address,
-                                IOByteCount  withLength,
-                                IODirection  withDirection,
-                                task_t       withTask)
-{
-    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
-    if (that)
-    {
-	if (that->initWithAddress(address, withLength, withDirection, withTask))
+	if (that->initWithAddress(address, length, direction, task))
 	    return that;
 
         that->release();
@@ -110,11 +369,71 @@
 IOMemoryDescriptor *
 IOMemoryDescriptor::withPhysicalAddress(
 				IOPhysicalAddress	address,
-				IOByteCount		withLength,
-				IODirection      	withDirection )
-{
-    return( IOMemoryDescriptor::withAddress( address, withLength,
-					withDirection, (task_t) 0  ));
+				IOByteCount		length,
+				IODirection      	direction )
+{
+#if TEST_P64
+    return (IOMemoryDescriptor::withAddressRange(address, length, (IOOptionBits) direction, NULL));
+#endif
+    IOGeneralMemoryDescriptor *self = new IOGeneralMemoryDescriptor;
+    if (self
+    && !self->initWithPhysicalAddress(address, length, direction)) {
+        self->release();
+        return 0;
+    }
+
+    return self;
+}
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withRanges(	IOVirtualRange * ranges,
+				UInt32           withCount,
+				IODirection      direction,
+				task_t           task,
+				bool             asReference)
+{
+    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
+    if (that)
+    {
+	if (that->initWithRanges(ranges, withCount, direction, task, asReference))
+	    return that;
+
+        that->release();
+    }
+    return 0;
+}
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withAddressRange(mach_vm_address_t address,
+					mach_vm_size_t length,
+					IOOptionBits   options,
+					task_t         task)
+{
+    IOAddressRange range = { address, length };
+    return (IOMemoryDescriptor::withAddressRanges(&range, 1, options, task));
+}
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withAddressRanges(IOAddressRange *   ranges,
+					UInt32           rangeCount,
+					IOOptionBits     options,
+					task_t           task)
+{
+    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
+    if (that)
+    {
+	if (task)
+	    options |= kIOMemoryTypeVirtual64;
+	else
+	    options |= kIOMemoryTypePhysical64;
+
+	if (that->initWithOptions(ranges, rangeCount, 0, task, options, /* mapper */ 0))
+	    return that;
+
+	that->release();
+    }
+
+    return 0;
 }
 
 
@@ -127,33 +446,48 @@
  * Passing the ranges as a reference will avoid an extra allocation.
  */
 IOMemoryDescriptor *
-IOMemoryDescriptor::withRanges(	IOVirtualRange * ranges,
-				UInt32           withCount,
-				IODirection      withDirection,
-				task_t           withTask,
-				bool             asReference = false)
-{
-    IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
-    if (that)
-    {
-	if (that->initWithRanges(ranges, withCount, withDirection, withTask, asReference))
-	    return that;
-
-        that->release();
-    }
+IOMemoryDescriptor::withOptions(void *		buffers,
+                                UInt32		count,
+                                UInt32		offset,
+                                task_t		task,
+                                IOOptionBits	opts,
+                                IOMapper *	mapper)
+{
+    IOGeneralMemoryDescriptor *self = new IOGeneralMemoryDescriptor;
+
+    if (self
+    && !self->initWithOptions(buffers, count, offset, task, opts, mapper))
+    {
+        self->release();
+        return 0;
+    }
+
+    return self;
+}
+
+// Can't leave abstract but this should never be used directly,
+bool IOMemoryDescriptor::initWithOptions(void *		buffers,
+                                         UInt32		count,
+                                         UInt32		offset,
+                                         task_t		task,
+                                         IOOptionBits	options,
+                                         IOMapper *	mapper)
+{
+    // @@@ gvdl: Should I panic?
+    panic("IOMD::initWithOptions called\n");
     return 0;
 }
 
 IOMemoryDescriptor *
 IOMemoryDescriptor::withPhysicalRanges(	IOPhysicalRange * ranges,
                                         UInt32          withCount,
-                                        IODirection     withDirection,
-                                        bool            asReference = false)
+                                        IODirection     direction,
+                                        bool            asReference)
 {
     IOGeneralMemoryDescriptor * that = new IOGeneralMemoryDescriptor;
     if (that)
     {
-	if (that->initWithPhysicalRanges(ranges, withCount, withDirection, asReference))
+	if (that->initWithPhysicalRanges(ranges, withCount, direction, asReference))
 	    return that;
 
         that->release();
@@ -165,15 +499,101 @@
 IOMemoryDescriptor::withSubRange(IOMemoryDescriptor *	of,
 				IOByteCount		offset,
 				IOByteCount		length,
-				IODirection		withDirection)
-{
-    IOSubMemoryDescriptor * that = new IOSubMemoryDescriptor;
-
-    if (that && !that->initSubRange(of, offset, length, withDirection)) {
-        that->release();
-	that = 0;
-    }
-    return that;
+				IODirection		direction)
+{
+    IOSubMemoryDescriptor *self = new IOSubMemoryDescriptor;
+
+    if (self && !self->initSubRange(of, offset, length, direction)) {
+        self->release();
+	self = 0;
+    }
+    return self;
+}
+
+IOMemoryDescriptor *
+IOMemoryDescriptor::withPersistentMemoryDescriptor(IOMemoryDescriptor *originalMD)
+{
+    IOGeneralMemoryDescriptor *origGenMD = 
+	OSDynamicCast(IOGeneralMemoryDescriptor, originalMD);
+
+    if (origGenMD)
+	return IOGeneralMemoryDescriptor::
+	    withPersistentMemoryDescriptor(origGenMD);
+    else
+	return 0;
+}
+
+IOMemoryDescriptor *
+IOGeneralMemoryDescriptor::withPersistentMemoryDescriptor(IOGeneralMemoryDescriptor *originalMD)
+{
+    ipc_port_t sharedMem = (ipc_port_t) originalMD->createNamedEntry();
+
+    if (!sharedMem)
+	return 0;
+   
+    if (sharedMem == originalMD->_memEntry) {
+	originalMD->retain();		    // Add a new reference to ourselves
+	ipc_port_release_send(sharedMem);   // Remove extra send right
+	return originalMD;
+    }
+
+    IOGeneralMemoryDescriptor * self = new IOGeneralMemoryDescriptor;
+    typePersMDData initData = { originalMD, sharedMem };
+
+    if (self
+    && !self->initWithOptions(&initData, 1, 0, 0, kIOMemoryTypePersistentMD, 0)) {
+        self->release();
+	self = 0;
+    }
+    return self;
+}
+
+void *IOGeneralMemoryDescriptor::createNamedEntry()
+{
+    kern_return_t error;
+    ipc_port_t sharedMem;
+
+    IOOptionBits type = _flags & kIOMemoryTypeMask;
+
+    user_addr_t range0Addr;
+    IOByteCount range0Len;
+    getAddrLenForInd(range0Addr, range0Len, type, _ranges, 0);
+    range0Addr = trunc_page_64(range0Addr);
+
+    vm_size_t size = ptoa_32(_pages);
+    vm_address_t kernelPage = (vm_address_t) range0Addr;
+
+    vm_map_t theMap = ((_task == kernel_task)
+			&& (kIOMemoryBufferPageable & _flags)) 
+		    ? IOPageableMapForAddress(kernelPage)
+		    : get_task_map(_task);
+
+    memory_object_size_t  actualSize = size;
+    vm_prot_t             prot       = VM_PROT_READ;
+#if CONFIG_EMBEDDED
+    if (kIODirectionOut != (kIODirectionOutIn & _flags))
+#endif
+	prot |= VM_PROT_WRITE;
+
+    if (_memEntry)
+	prot |= MAP_MEM_NAMED_REUSE;
+
+    error = mach_make_memory_entry_64(theMap,
+	    &actualSize, range0Addr, prot, &sharedMem, (ipc_port_t) _memEntry);
+
+    if (KERN_SUCCESS == error) {
+	if (actualSize == size) {
+	    return sharedMem;
+	} else {
+#if IOASSERT
+	    IOLog("IOGMD::mach_make_memory_entry_64 (%08llx) size (%08lx:%08x)\n",
+			(UInt64)range0Addr, (UInt32)actualSize, size);
+#endif    
+	    ipc_port_release_send( sharedMem );
+	}
+    }
+
+    return MACH_PORT_NULL;
 }
 
 /*
@@ -223,29 +643,129 @@
     return initWithPhysicalRanges( &_singleRange.p, 1, withDirection, true);
 }
 
+bool
+IOGeneralMemoryDescriptor::initWithPhysicalRanges(
+                                IOPhysicalRange * ranges,
+                                UInt32            count,
+                                IODirection       direction,
+                                bool              reference)
+{
+    IOOptionBits mdOpts = direction | kIOMemoryTypePhysical;
+
+    if (reference)
+        mdOpts |= kIOMemoryAsReference;
+
+    return initWithOptions(ranges, count, 0, 0, mdOpts, /* mapper */ 0);
+}
+
+bool
+IOGeneralMemoryDescriptor::initWithRanges(
+                                   IOVirtualRange * ranges,
+                                   UInt32           count,
+                                   IODirection      direction,
+                                   task_t           task,
+                                   bool             reference)
+{
+    IOOptionBits mdOpts = direction;
+
+    if (reference)
+        mdOpts |= kIOMemoryAsReference;
+
+    if (task) {
+        mdOpts |= kIOMemoryTypeVirtual;
+
+	// Auto-prepare if this is a kernel memory descriptor as very few
+	// clients bother to prepare() kernel memory.
+	// But it was not enforced so what are you going to do?
+        if (task == kernel_task)
+            mdOpts |= kIOMemoryAutoPrepare;
+    }
+    else
+        mdOpts |= kIOMemoryTypePhysical;
+    
+    return initWithOptions(ranges, count, 0, task, mdOpts, /* mapper */ 0);
+}
+
 /*
- * initWithRanges:
+ * initWithOptions:
  *
- * Initialize an IOMemoryDescriptor. The buffer is made up of several
- * virtual address ranges, from a given task
+ *  IOMemoryDescriptor. The buffer is made up of several virtual address ranges,
+ * from a given task, several physical ranges, an UPL from the ubc
+ * system or a uio (may be 64bit) from the BSD subsystem.
  *
  * Passing the ranges as a reference will avoid an extra allocation.
  *
- * An IOMemoryDescriptor can be re-used by calling initWithAddress or
- * initWithRanges again on an existing instance -- note this behavior
- * is not commonly supported in other I/O Kit classes, although it is
- * supported here.
+ * An IOMemoryDescriptor can be re-used by calling initWithOptions again on an
+ * existing instance -- note this behavior is not commonly supported in other
+ * I/O Kit classes, although it is supported here.
  */
+
 bool
-IOGeneralMemoryDescriptor::initWithRanges(
-                                   IOVirtualRange * ranges,
-                                   UInt32           withCount,
-                                   IODirection      withDirection,
-                                   task_t           withTask,
-                                   bool             asReference = false)
-{
-    assert(ranges);
-    assert(withCount);
+IOGeneralMemoryDescriptor::initWithOptions(void *	buffers,
+                                           UInt32	count,
+                                           UInt32	offset,
+                                           task_t	task,
+                                           IOOptionBits	options,
+                                           IOMapper *	mapper)
+{
+    IOOptionBits type = options & kIOMemoryTypeMask;
+
+    // Grab the original MD's configuation data to initialse the
+    // arguments to this function.
+    if (kIOMemoryTypePersistentMD == type) {
+
+	typePersMDData *initData = (typePersMDData *) buffers;
+	const IOGeneralMemoryDescriptor *orig = initData->fMD;
+	ioGMDData *dataP = getDataP(orig->_memoryEntries);
+
+	// Only accept persistent memory descriptors with valid dataP data.
+	assert(orig->_rangesCount == 1);
+	if ( !(orig->_flags & kIOMemoryPersistent) || !dataP)
+	    return false;
+
+	_memEntry = initData->fMemEntry;	// Grab the new named entry
+	options = orig->_flags | kIOMemoryAsReference; 
+	_singleRange = orig->_singleRange;	// Initialise our range
+	buffers = &_singleRange;
+	count = 1;
+
+	// Now grab the original task and whatever mapper was previously used
+	task = orig->_task;
+	mapper = dataP->fMapper;
+
+	// We are ready to go through the original initialisation now
+    }
+
+    switch (type) {
+    case kIOMemoryTypeUIO:
+    case kIOMemoryTypeVirtual:
+    case kIOMemoryTypeVirtual64:
+        assert(task);
+        if (!task)
+            return false;
+
+	if (vm_map_is_64bit(get_task_map(task)) 
+	    && (kIOMemoryTypeVirtual == type) 
+	    && ((IOVirtualRange *) buffers)->address)
+	{
+	    OSReportWithBacktrace("IOMemoryDescriptor: attempt to create 32b virtual in 64b task, use ::withAddressRange()");
+            return false;
+	}
+	break;
+
+    case kIOMemoryTypePhysical:		// Neither Physical nor UPL should have a task
+    case kIOMemoryTypePhysical64:
+	mapper = kIOMapperNone;
+
+    case kIOMemoryTypeUPL:
+        assert(!task);
+        break;
+    default:
+        return false;	/* bad argument */
+    }
+
+    assert(buffers);
+    assert(count);
 
     /*
      * We can check the _initialized  instance variable before having ever set
@@ -253,75 +773,216 @@
      * variables are zeroed on an object's allocation.
      */
 
-    if (_initialized == false)
-    {
-        if (super::init() == false)  return false;
-        _initialized = true;
-    }
-    else
-    {
+    if (_initialized) {
         /*
          * An existing memory descriptor is being retargeted to point to
          * somewhere else.  Clean up our present state.
          */
-
-        assert(_wireCount == 0);
-
-        while (_wireCount)
-            complete();
-        if (_kernPtrAligned)
-            unmapFromKernel();
+	IOOptionBits type = _flags & kIOMemoryTypeMask;
+	if ((kIOMemoryTypePhysical != type) && (kIOMemoryTypePhysical64 != type))
+	{
+	    while (_wireCount)
+		complete();
+	}
         if (_ranges.v && _rangesIsAllocated)
-            IODelete(_ranges.v, IOVirtualRange, _rangesCount);
-    }
-
-    /*
-     * Initialize the memory descriptor.
-     */
-
-    _ranges.v              = 0;
-    _rangesCount           = withCount;
-    _rangesIsAllocated     = asReference ? false : true;
-    _direction             = withDirection;
-    _length                = 0;
-    _task                  = withTask;
-    _position              = 0;
-    _positionAtIndex       = 0;
-    _positionAtOffset      = 0;
-    _kernPtrAligned        = 0;
-    _cachedPhysicalAddress = 0;
-    _cachedVirtualAddress  = 0;
-    _flags		   = 0;
-
-    if (withTask && (withTask != kernel_task))
-        _flags |= kIOMemoryRequiresWire;
-
-    if (asReference)
-        _ranges.v = ranges;
-    else
-    {
-        _ranges.v = IONew(IOVirtualRange, withCount);
-        if (_ranges.v == 0)  return false;
-        bcopy(/* from */ ranges, _ranges.v, withCount * sizeof(IOVirtualRange));
-    } 
-
-    for (unsigned index = 0; index < _rangesCount; index++)
-    {
-        _length += _ranges.v[index].length;
+	{
+	    if (kIOMemoryTypeUIO == type)
+		uio_free((uio_t) _ranges.v);
+	    else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type))
+		IODelete(_ranges.v64, IOAddressRange, _rangesCount);
+	    else
+		IODelete(_ranges.v, IOVirtualRange, _rangesCount);
+	}
+
+	if (_memEntry)
+	    { ipc_port_release_send((ipc_port_t) _memEntry); _memEntry = 0; }
+	if (_mappings)
+	    _mappings->flushCollection();
+    }
+    else {
+        if (!super::init())
+            return false;
+        _initialized = true;
+    }
+
+    // Grab the appropriate mapper
+    if (mapper == kIOMapperNone)
+        mapper = 0;	// No Mapper
+    else if (mapper == kIOMapperSystem) {
+        IOMapper::checkForSystemMapper();
+        gIOSystemMapper = mapper = IOMapper::gSystem;
+    }
+
+    // Remove the dynamic internal use flags from the initial setting
+    options 		  &= ~(kIOMemoryPreparedReadOnly);
+    _flags		   = options;
+    _task                  = task;
+
+    // DEPRECATED variable initialisation
+    _direction             = (IODirection) (_flags & kIOMemoryDirectionMask);
+
+    __iomd_reservedA = 0;
+    __iomd_reservedB = 0;
+    _highestPage = 0;
+
+    if (kIOMemoryThreadSafe & options)
+    {
+	if (!_prepareLock)
+	    _prepareLock = IOLockAlloc();
+    }
+    else if (_prepareLock)
+    {
+	IOLockFree(_prepareLock);
+	_prepareLock = NULL;
+    }
+	
+    if (kIOMemoryTypeUPL == type) {
+
+        ioGMDData *dataP;
+        unsigned int dataSize = computeDataSize(/* pages */ 0, /* upls */ 1);
+
+        if (!_memoryEntries) {
+            _memoryEntries = OSData::withCapacity(dataSize);
+            if (!_memoryEntries)
+                return false;
+        }
+        else if (!_memoryEntries->initWithCapacity(dataSize))
+            return false;
+
+        _memoryEntries->appendBytes(0, sizeof(ioGMDData));
+        dataP = getDataP(_memoryEntries);
+        dataP->fMapper = mapper;
+        dataP->fPageCnt = 0;
+
+ //       _wireCount++;	// UPLs start out life wired
+
+        _length    = count;
+        _pages    += atop_32(offset + count + PAGE_MASK) - atop_32(offset);
+
+        ioPLBlock iopl;
+        upl_page_info_t *pageList = UPL_GET_INTERNAL_PAGE_LIST((upl_t) buffers);
+
+        iopl.fIOPL = (upl_t) buffers;
+        // Set the flag kIOPLOnDevice convieniently equal to 1
+        iopl.fFlags  = pageList->device | kIOPLExternUPL;
+        iopl.fIOMDOffset = 0;
+
+        _highestPage = upl_get_highest_page(iopl.fIOPL);
+
+        if (!pageList->device) {
+            // Pre-compute the offset into the UPL's page list
+            pageList = &pageList[atop_32(offset)];
+            offset &= PAGE_MASK;
+            if (mapper) {
+                iopl.fMappedBase = mapper->iovmAlloc(_pages);
+                mapper->iovmInsert(iopl.fMappedBase, 0, pageList, _pages);
+            }
+	    else
+		iopl.fMappedBase = 0;
+        }
+	else
+	    iopl.fMappedBase = 0;
+        iopl.fPageInfo = (vm_address_t) pageList;
+        iopl.fPageOffset = offset;
+
+        _memoryEntries->appendBytes(&iopl, sizeof(iopl));
+    }
+    else {
+	// kIOMemoryTypeVirtual  | kIOMemoryTypeVirtual64 | kIOMemoryTypeUIO 
+	// kIOMemoryTypePhysical | kIOMemoryTypePhysical64
+	
+	// Initialize the memory descriptor
+	if (options & kIOMemoryAsReference) {
+	    _rangesIsAllocated = false;
+
+	    // Hack assignment to get the buffer arg into _ranges.
+	    // I'd prefer to do _ranges = (Ranges) buffers, but that doesn't
+	    // work, C++ sigh.
+	    // This also initialises the uio & physical ranges.
+	    _ranges.v = (IOVirtualRange *) buffers;
+	}
+	else {
+	    _rangesIsAllocated = true;
+	    switch (_flags & kIOMemoryTypeMask)
+	    {
+	      case kIOMemoryTypeUIO:
+		_ranges.v = (IOVirtualRange *) uio_duplicate((uio_t) buffers);
+		break;
+
+	      case kIOMemoryTypeVirtual64:
+	      case kIOMemoryTypePhysical64:
+		_ranges.v64 = IONew(IOAddressRange, count);
+		if (!_ranges.v64)
+		    return false;
+		bcopy(buffers, _ranges.v, count * sizeof(IOAddressRange));
+		break;
+	      case kIOMemoryTypeVirtual:
+	      case kIOMemoryTypePhysical:
+		_ranges.v = IONew(IOVirtualRange, count);
+		if (!_ranges.v)
+		    return false;
+		bcopy(buffers, _ranges.v, count * sizeof(IOVirtualRange));
+		break;
+	    }
+	} 
+
+	// Find starting address within the vector of ranges
+	Ranges vec = _ranges;
+	UInt32 length = 0;
+	UInt32 pages = 0;
+	for (unsigned ind = 0; ind < count;  ind++) {
+	    user_addr_t addr;
+	    UInt32 len;
+
+	    // addr & len are returned by this function
+	    getAddrLenForInd(addr, len, type, vec, ind);
+	    pages += (atop_64(addr + len + PAGE_MASK) - atop_64(addr));
+	    len += length;
+	    assert(len >= length);	// Check for 32 bit wrap around
+	    length = len;
+
+	    if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type))
+	    {
+		ppnum_t highPage = atop_64(addr + len - 1);
+		if (highPage > _highestPage)
+		    _highestPage = highPage;
+	    }
+	} 
+	_length      = length;
+	_pages       = pages;
+	_rangesCount = count;
+
+        // Auto-prepare memory at creation time.
+        // Implied completion when descriptor is free-ed
+        if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type))
+            _wireCount++;	// Physical MDs are, by definition, wired
+        else { /* kIOMemoryTypeVirtual | kIOMemoryTypeVirtual64 | kIOMemoryTypeUIO */
+            ioGMDData *dataP;
+            unsigned dataSize = computeDataSize(_pages, /* upls */ count * 2);
+
+            if (!_memoryEntries) {
+                _memoryEntries = OSData::withCapacity(dataSize);
+                if (!_memoryEntries)
+		    return false;
+            }
+            else if (!_memoryEntries->initWithCapacity(dataSize))
+                return false;
+    
+            _memoryEntries->appendBytes(0, sizeof(ioGMDData));
+            dataP = getDataP(_memoryEntries);
+            dataP->fMapper = mapper;
+            dataP->fPageCnt = _pages;
+
+	    if ( (kIOMemoryPersistent & _flags) && !_memEntry)
+		_memEntry = createNamedEntry();
+
+            if ((_flags & kIOMemoryAutoPrepare)
+             && prepare() != kIOReturnSuccess)
+                return false;
+        }
     }
 
     return true;
-}
-
-bool
-IOGeneralMemoryDescriptor::initWithPhysicalRanges(	IOPhysicalRange * ranges,
-                                        	UInt32           withCount,
-                                        	IODirection      withDirection,
-                                        	bool             asReference = false)
-{
-#warning assuming virtual, physical addresses same size
-    return( initWithRanges( (IOVirtualRange *) ranges,
-			withCount, withDirection, (task_t) 0, asReference ));
 }
 
 /*
@@ -331,97 +992,56 @@
  */
 void IOGeneralMemoryDescriptor::free()
 {
-    while (_wireCount)
-        complete();
-    if (_kernPtrAligned)
-        unmapFromKernel();
+    IOOptionBits type = _flags & kIOMemoryTypeMask;
+
+    if( reserved)
+    {
+	LOCK;
+	reserved->memory = 0;
+	UNLOCK;
+    }
+
+    if ((kIOMemoryTypePhysical != type) && (kIOMemoryTypePhysical64 != type))
+    {
+	while (_wireCount)
+	    complete();
+    }
+    if (_memoryEntries)
+        _memoryEntries->release();
+
     if (_ranges.v && _rangesIsAllocated)
-        IODelete(_ranges.v, IOVirtualRange, _rangesCount);
-    if( _memEntry)
+    {
+	if (kIOMemoryTypeUIO == type)
+	    uio_free((uio_t) _ranges.v);
+	else if ((kIOMemoryTypeVirtual64 == type) || (kIOMemoryTypePhysical64 == type))
+	    IODelete(_ranges.v64, IOAddressRange, _rangesCount);
+	else
+	    IODelete(_ranges.v, IOVirtualRange, _rangesCount);
+    }
+
+    if (reserved && reserved->devicePager)
+	device_pager_deallocate( (memory_object_t) reserved->devicePager );
+
+    // memEntry holds a ref on the device pager which owns reserved
+    // (ExpansionData) so no reserved access after this point
+    if (_memEntry)
         ipc_port_release_send( (ipc_port_t) _memEntry );
+
+    if (_prepareLock)
+	IOLockFree(_prepareLock);
+
     super::free();
 }
 
-void IOGeneralMemoryDescriptor::unmapFromKernel()
-{
-    kern_return_t krtn;
-    vm_offset_t off;
-    // Pull the shared pages out of the task map
-    // Do we need to unwire it first?
-    for ( off = 0; off < _kernSize; off += page_size )
-    {
-	pmap_change_wiring(
-			kernel_pmap,
-			_kernPtrAligned + off,
-			FALSE);
-
-	pmap_remove(
-			kernel_pmap,
-			_kernPtrAligned + off,
-			_kernPtrAligned + off + page_size);
-    }
-    // Free the former shmem area in the task
-    krtn = vm_deallocate(kernel_map,
-			_kernPtrAligned,
-			_kernSize );
-    assert(krtn == KERN_SUCCESS);
-    _kernPtrAligned = 0;
-}
-
-void IOGeneralMemoryDescriptor::mapIntoKernel(unsigned rangeIndex)
-{
-    kern_return_t krtn;
-    vm_offset_t off;
-
-    if (_kernPtrAligned)
-    {
-        if (_kernPtrAtIndex == rangeIndex)  return;
-        unmapFromKernel();
-        assert(_kernPtrAligned == 0);
-    }
- 
-    vm_offset_t srcAlign = trunc_page(_ranges.v[rangeIndex].address);
-
-    _kernSize = trunc_page(_ranges.v[rangeIndex].address +
-                           _ranges.v[rangeIndex].length  +
-                           page_size - 1) - srcAlign;
-
-    /* Find some memory of the same size in kernel task.  We use vm_allocate()
-    to do this. vm_allocate inserts the found memory object in the
-    target task's map as a side effect. */
-    krtn = vm_allocate( kernel_map,
-	    &_kernPtrAligned,
-	    _kernSize,
-	    VM_FLAGS_ANYWHERE|VM_MAKE_TAG(VM_MEMORY_IOKIT) );  // Find first fit
-    assert(krtn == KERN_SUCCESS);
-    if(krtn)  return;
-
-    /* For each page in the area allocated from the kernel map,
-	    find the physical address of the page.
-	    Enter the page in the target task's pmap, at the
-	    appropriate target task virtual address. */
-    for ( off = 0; off < _kernSize; off += page_size )
-    {
-	vm_offset_t kern_phys_addr, phys_addr;
-	if( _task)
-	    phys_addr = pmap_extract( get_task_pmap(_task), srcAlign + off );
-	else
-	    phys_addr = srcAlign + off;
-        assert(phys_addr);
-	if(phys_addr == 0)  return;
-
-	// Check original state.
-	kern_phys_addr = pmap_extract( kernel_pmap, _kernPtrAligned + off );
-	// Set virtual page to point to the right physical one
-	pmap_enter(
-	    kernel_pmap,
-	    _kernPtrAligned + off,
-	    phys_addr,
-	    VM_PROT_READ|VM_PROT_WRITE,
-	    TRUE);
-    }
-    _kernPtrAtIndex = rangeIndex;
-}
+/* DEPRECATED */ void IOGeneralMemoryDescriptor::unmapFromKernel()
+/* DEPRECATED */ {
+                    panic("IOGMD::unmapFromKernel deprecated");
+/* DEPRECATED */ }
+/* DEPRECATED */ 
+/* DEPRECATED */ void IOGeneralMemoryDescriptor::mapIntoKernel(unsigned rangeIndex)
+/* DEPRECATED */ {
+                    panic("IOGMD::mapIntoKernel deprecated");
+/* DEPRECATED */ }
 
 /*
  * getDirection:
@@ -443,8 +1063,7 @@
     return _length;
 }
 
-void IOMemoryDescriptor::setTag(
-	IOOptionBits		tag )
+void IOMemoryDescriptor::setTag( IOOptionBits tag )
 {
     _tag = tag;    
 }
@@ -454,317 +1073,932 @@
     return( _tag);
 }
 
-/*
- * setPosition
- *
- * Set the logical start position inside the client buffer.
- *
- * It is convention that the position reflect the actual byte count that
- * is successfully transferred into or out of the buffer, before the I/O
- * request is "completed" (ie. sent back to its originator).
- */
-
-void IOGeneralMemoryDescriptor::setPosition(IOByteCount position)
-{
-    assert(position <= _length);
-
-    if (position >= _length)
-    {
-        _position         = _length;
-        _positionAtIndex  = _rangesCount;          /* careful: out-of-bounds */
-        _positionAtOffset = 0;
-        return;
-    }
-
-    if (position < _position)
-    {
-	_positionAtOffset = position;
-	_positionAtIndex  = 0;
-    }
+// @@@ gvdl: who is using this API?  Seems like a wierd thing to implement.
+IOPhysicalAddress
+IOMemoryDescriptor::getSourceSegment( IOByteCount   offset, IOByteCount * length )
+{
+    addr64_t physAddr = 0;
+
+    if( prepare() == kIOReturnSuccess) {
+        physAddr = getPhysicalSegment64( offset, length );
+        complete();
+    }
+
+    return( (IOPhysicalAddress) physAddr ); // truncated but only page offset is used
+}
+
+IOByteCount IOMemoryDescriptor::readBytes
+                (IOByteCount offset, void *bytes, IOByteCount length)
+{
+    addr64_t dstAddr = (addr64_t) (UInt32) bytes;
+    IOByteCount remaining;
+
+    // Assert that this entire I/O is withing the available range
+    assert(offset < _length);
+    assert(offset + length <= _length);
+    if (offset >= _length) {
+        return 0;
+    }
+
+    remaining = length = min(length, _length - offset);
+    while (remaining) {	// (process another target segment?)
+        addr64_t	srcAddr64;
+        IOByteCount	srcLen;
+
+        srcAddr64 = getPhysicalSegment64(offset, &srcLen);
+        if (!srcAddr64)
+            break;
+
+        // Clip segment length to remaining
+        if (srcLen > remaining)
+            srcLen = remaining;
+
+        copypv(srcAddr64, dstAddr, srcLen,
+                            cppvPsrc | cppvNoRefSrc | cppvFsnk | cppvKmap);
+
+        dstAddr   += srcLen;
+        offset    += srcLen;
+        remaining -= srcLen;
+    }
+
+    assert(!remaining);
+
+    return length - remaining;
+}
+
+IOByteCount IOMemoryDescriptor::writeBytes
+                (IOByteCount offset, const void *bytes, IOByteCount length)
+{
+    addr64_t srcAddr = (addr64_t) (UInt32) bytes;
+    IOByteCount remaining;
+
+    // Assert that this entire I/O is withing the available range
+    assert(offset < _length);
+    assert(offset + length <= _length);
+
+    assert( !(kIOMemoryPreparedReadOnly & _flags) );
+
+    if ( (kIOMemoryPreparedReadOnly & _flags) || offset >= _length) {
+        return 0;
+    }
+
+    remaining = length = min(length, _length - offset);
+    while (remaining) {	// (process another target segment?)
+        addr64_t    dstAddr64;
+        IOByteCount dstLen;
+
+        dstAddr64 = getPhysicalSegment64(offset, &dstLen);
+        if (!dstAddr64)
+            break;
+
+        // Clip segment length to remaining
+        if (dstLen > remaining)
+            dstLen = remaining;
+
+        copypv(srcAddr, (addr64_t) dstAddr64, dstLen,
+                            cppvPsnk | cppvFsnk | cppvNoRefSrc | cppvNoModSnk | cppvKmap);
+
+        srcAddr   += dstLen;
+        offset    += dstLen;
+        remaining -= dstLen;
+    }
+
+    assert(!remaining);
+
+    return length - remaining;
+}
+
+// osfmk/device/iokit_rpc.c
+extern "C" unsigned int IODefaultCacheBits(addr64_t pa);
+
+/* DEPRECATED */ void IOGeneralMemoryDescriptor::setPosition(IOByteCount position)
+/* DEPRECATED */ {
+                    panic("IOGMD::setPosition deprecated");
+/* DEPRECATED */ }
+
+IOReturn IOGeneralMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
+{
+    if (kIOMDGetCharacteristics == op) {
+
+	if (dataSize < sizeof(IOMDDMACharacteristics))
+	    return kIOReturnUnderrun;
+
+	IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
+	data->fLength = _length;
+	data->fSGCount = _rangesCount;
+	data->fPages = _pages;
+	data->fDirection = _direction;
+	if (!_wireCount)
+	    data->fIsPrepared = false;
+	else {
+	    data->fIsPrepared = true;
+	    data->fHighestPage = _highestPage;
+	    if (_memoryEntries) {
+		ioGMDData *gmdData = getDataP(_memoryEntries);
+		ioPLBlock *ioplList = getIOPLList(gmdData);
+		UInt count = getNumIOPL(_memoryEntries, gmdData);
+
+		data->fIsMapped = (gmdData->fMapper && _pages && (count > 0)
+			       && ioplList[0].fMappedBase);
+		if (count == 1)
+		    data->fPageAlign = (ioplList[0].fPageOffset & PAGE_MASK) | ~PAGE_MASK;
+	    }
+	    else
+		data->fIsMapped = false;
+	}
+
+	return kIOReturnSuccess;
+    }
+    else if (!(kIOMDWalkSegments & op))
+	return kIOReturnBadArgument;
+
+    // Get the next segment
+    struct InternalState {
+	IOMDDMAWalkSegmentArgs fIO;
+	UInt fOffset2Index;
+	UInt fIndex;
+	UInt fNextOffset;
+    } *isP;
+
+    // Find the next segment
+    if (dataSize < sizeof(*isP))
+	return kIOReturnUnderrun;
+
+    isP = (InternalState *) vData;
+    UInt offset = isP->fIO.fOffset;
+    bool mapped = isP->fIO.fMapped;
+
+    if (offset >= _length)
+	return (offset == _length)? kIOReturnOverrun : kIOReturnInternalError;
+
+    // Validate the previous offset
+    UInt ind, off2Ind = isP->fOffset2Index;
+    if ((kIOMDFirstSegment != op) 
+	&& offset 
+	&& (offset == isP->fNextOffset || off2Ind <= offset))
+	ind = isP->fIndex;
     else
-    {
-	_positionAtOffset += (position - _position);
-    }
-    _position = position;
-
-    while (_positionAtOffset >= _ranges.v[_positionAtIndex].length)
-    {
-        _positionAtOffset -= _ranges.v[_positionAtIndex].length;
-        _positionAtIndex++;
-    }
-}
-
-/*
- * readBytes:
- *
- * Copy data from the memory descriptor's buffer into the specified buffer,
- * relative to the current position.   The memory descriptor's position is
- * advanced based on the number of bytes copied.
- */
-
-IOByteCount IOGeneralMemoryDescriptor::readBytes(IOByteCount offset,
-					void * bytes, IOByteCount withLength)
-{
-    IOByteCount bytesLeft;
-    void *    segment;
-    IOByteCount segmentLength;
-
-    if( offset != _position)
-	setPosition( offset );
-
-    withLength = min(withLength, _length - _position);
-    bytesLeft  = withLength;
-
-#if 0
-    while (bytesLeft && (_position < _length))
-    {
-	/* Compute the relative length to the end of this virtual segment. */
-        segmentLength = min(_ranges.v[_positionAtIndex].length - _positionAtOffset, bytesLeft);
-
-	/* Compute the relative address of this virtual segment. */
-        segment = (void *)(_ranges.v[_positionAtIndex].address + _positionAtOffset);
-
-	if (KERN_SUCCESS != vm_map_read_user(getMapForTask(_task, segment),
-		/* from */ (vm_offset_t) segment, /* to */ (vm_offset_t) bytes,
-		/* size */ segmentLength))
+	ind = off2Ind = 0;	// Start from beginning
+
+    UInt length;
+    UInt64 address;
+    if ( (_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical) {
+
+	// Physical address based memory descriptor
+	const IOPhysicalRange *physP = (IOPhysicalRange *) &_ranges.p[0];
+
+	// Find the range after the one that contains the offset
+	UInt len;
+	for (len = 0; off2Ind <= offset; ind++) {
+	    len = physP[ind].length;
+	    off2Ind += len;
+	}
+
+	// Calculate length within range and starting address
+	length   = off2Ind - offset;
+	address  = physP[ind - 1].address + len - length;
+
+	// see how far we can coalesce ranges
+	while (ind < _rangesCount && address + length == physP[ind].address) {
+	    len = physP[ind].length;
+	    length += len;
+	    off2Ind += len;
+	    ind++;
+	}
+
+	// correct contiguous check overshoot
+	ind--;
+	off2Ind -= len;
+    }
+    else if ( (_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64) {
+
+	// Physical address based memory descriptor
+	const IOAddressRange *physP = (IOAddressRange *) &_ranges.v64[0];
+
+	// Find the range after the one that contains the offset
+	mach_vm_size_t len;
+	for (len = 0; off2Ind <= offset; ind++) {
+	    len = physP[ind].length;
+	    off2Ind += len;
+	}
+
+	// Calculate length within range and starting address
+	length   = off2Ind - offset;
+	address  = physP[ind - 1].address + len - length;
+
+	// see how far we can coalesce ranges
+	while (ind < _rangesCount && address + length == physP[ind].address) {
+	    len = physP[ind].length;
+	    length += len;
+	    off2Ind += len;
+	    ind++;
+	}
+
+	// correct contiguous check overshoot
+	ind--;
+	off2Ind -= len;
+    }
+    else do {
+	if (!_wireCount)
+	    panic("IOGMD: not wired for the IODMACommand");
+
+	assert(_memoryEntries);
+
+	ioGMDData * dataP = getDataP(_memoryEntries);
+	const ioPLBlock *ioplList = getIOPLList(dataP);
+	UInt numIOPLs = getNumIOPL(_memoryEntries, dataP);
+	upl_page_info_t *pageList = getPageList(dataP);
+
+	assert(numIOPLs > 0);
+
+	// Scan through iopl info blocks looking for block containing offset
+	while (ind < numIOPLs && offset >= ioplList[ind].fIOMDOffset)
+	    ind++;
+
+	// Go back to actual range as search goes past it
+	ioPLBlock ioplInfo = ioplList[ind - 1];
+	off2Ind = ioplInfo.fIOMDOffset;
+
+	if (ind < numIOPLs)
+	    length = ioplList[ind].fIOMDOffset;
+	else
+	    length = _length;
+	length -= offset;			// Remainder within iopl
+
+	// Subtract offset till this iopl in total list
+	offset -= off2Ind;
+
+	// If a mapped address is requested and this is a pre-mapped IOPL
+	// then just need to compute an offset relative to the mapped base.
+	if (mapped && ioplInfo.fMappedBase) {
+	    offset += (ioplInfo.fPageOffset & PAGE_MASK);
+	    address = ptoa_64(ioplInfo.fMappedBase) + offset;
+	    continue;	// Done leave do/while(false) now
+	}
+
+	// The offset is rebased into the current iopl.
+	// Now add the iopl 1st page offset.
+	offset += ioplInfo.fPageOffset;
+
+	// For external UPLs the fPageInfo field points directly to
+	// the upl's upl_page_info_t array.
+	if (ioplInfo.fFlags & kIOPLExternUPL)
+	    pageList = (upl_page_info_t *) ioplInfo.fPageInfo;
+	else
+	    pageList = &pageList[ioplInfo.fPageInfo];
+
+	// Check for direct device non-paged memory
+	if ( ioplInfo.fFlags & kIOPLOnDevice ) {
+	    address = ptoa_64(pageList->phys_addr) + offset;
+	    continue;	// Done leave do/while(false) now
+	}
+
+	// Now we need compute the index into the pageList
+	UInt pageInd = atop_32(offset);
+	offset &= PAGE_MASK;
+
+	// Compute the starting address of this segment
+	IOPhysicalAddress pageAddr = pageList[pageInd].phys_addr;
+	address = ptoa_64(pageAddr) + offset;
+
+	// length is currently set to the length of the remainider of the iopl.
+	// We need to check that the remainder of the iopl is contiguous.
+	// This is indicated by pageList[ind].phys_addr being sequential.
+	IOByteCount contigLength = PAGE_SIZE - offset;
+	while (contigLength < length
+		&& ++pageAddr == pageList[++pageInd].phys_addr)
 	{
-	    assert( false );
-            bytesLeft = withLength;
+	    contigLength += PAGE_SIZE;
+	}
+
+	if (contigLength < length)
+	    length = contigLength;
+	
+
+	assert(address);
+	assert(length);
+
+    } while (false);
+
+    // Update return values and state
+    isP->fIO.fIOVMAddr = address;
+    isP->fIO.fLength   = length;
+    isP->fIndex        = ind;
+    isP->fOffset2Index = off2Ind;
+    isP->fNextOffset   = isP->fIO.fOffset + length;
+
+    return kIOReturnSuccess;
+}
+
+addr64_t
+IOGeneralMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+    IOReturn    ret;
+    IOByteCount length  = 0;
+    addr64_t    address = 0;
+
+    if (gIOSystemMapper && (kIOMemoryTypePhysical == (_flags & kIOMemoryTypeMask)))
+	return (super::getPhysicalSegment64(offset, lengthOfSegment));
+
+    if (offset < _length) // (within bounds?)
+    {
+	IOMDDMAWalkSegmentState _state;
+	IOMDDMAWalkSegmentArgs * state = (IOMDDMAWalkSegmentArgs *) &_state;
+
+	state->fOffset = offset;
+	state->fLength = _length - offset;
+	state->fMapped = false;
+
+	ret = dmaCommandOperation(kIOMDFirstSegment, _state, sizeof(_state));
+
+	if ((kIOReturnSuccess != ret) && (kIOReturnOverrun != ret))
+		DEBG("getPhysicalSegment64 dmaCommandOperation(%lx), %p, offset %qx, addr %qx, len %qx\n", 
+					ret, this, state->fOffset,
+					state->fIOVMAddr, state->fLength);
+	if (kIOReturnSuccess == ret)
+	{
+	    address = state->fIOVMAddr;
+	    length  = state->fLength;
+	}
+        if (!address)
+            length = 0;
+    }
+
+    if (lengthOfSegment)
+        *lengthOfSegment = length;
+
+    return (address);
+}
+
+IOPhysicalAddress
+IOGeneralMemoryDescriptor::getPhysicalSegment(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+    IOReturn          ret;
+    IOByteCount       length  = 0;
+    addr64_t	      address = 0;
+
+//  assert(offset <= _length);
+
+    if (offset < _length) // (within bounds?)
+    {
+	IOMDDMAWalkSegmentState _state;
+	IOMDDMAWalkSegmentArgs * state = (IOMDDMAWalkSegmentArgs *) &_state;
+
+	state->fOffset = offset;
+	state->fLength = _length - offset;
+	state->fMapped = true;
+
+	ret = dmaCommandOperation(
+		kIOMDFirstSegment, _state, sizeof(_state));
+
+	if ((kIOReturnSuccess != ret) && (kIOReturnOverrun != ret))
+	    DEBG("getPhysicalSegment dmaCommandOperation(%lx), %p, offset %qx, addr %qx, len %qx\n", 
+				    ret, this, state->fOffset,
+				    state->fIOVMAddr, state->fLength);
+	if (kIOReturnSuccess == ret)
+	{
+	    address = state->fIOVMAddr;
+	    length  = state->fLength;
+	}
+
+        if (!address)
+            length = 0;
+    }
+
+    if ((address + length) > 0x100000000ULL)
+    {
+	panic("getPhysicalSegment() out of 32b range 0x%qx, len 0x%lx, class %s",
+		    address, length, (getMetaClass())->getClassName());
+    }
+
+    if (lengthOfSegment)
+        *lengthOfSegment = length;
+
+    return ((IOPhysicalAddress) address);
+}
+
+addr64_t
+IOMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+    IOPhysicalAddress phys32;
+    IOByteCount	      length;
+    addr64_t 	      phys64;
+    IOMapper *        mapper = 0;
+
+    phys32 = getPhysicalSegment(offset, lengthOfSegment);
+    if (!phys32)
+	return 0;
+
+    if (gIOSystemMapper)
+	mapper = gIOSystemMapper;
+
+    if (mapper)
+    {
+	IOByteCount origLen;
+
+	phys64 = mapper->mapAddr(phys32);
+	origLen = *lengthOfSegment;
+	length = page_size - (phys64 & (page_size - 1));
+	while ((length < origLen)
+	    && ((phys64 + length) == mapper->mapAddr(phys32 + length)))
+	    length += page_size;
+	if (length > origLen)
+	    length = origLen;
+
+	*lengthOfSegment = length;
+    }
+    else
+	phys64 = (addr64_t) phys32;
+
+    return phys64;
+}
+
+IOPhysicalAddress
+IOGeneralMemoryDescriptor::getSourceSegment(IOByteCount offset, IOByteCount *lengthOfSegment)
+{
+    IOPhysicalAddress address = 0;
+    IOPhysicalLength  length  = 0;
+    IOOptionBits      type    = _flags & kIOMemoryTypeMask;
+
+    assert(offset <= _length);
+
+    if ( type == kIOMemoryTypeUPL)
+	return super::getSourceSegment( offset, lengthOfSegment );
+    else if ( offset < _length ) // (within bounds?)
+    {
+        unsigned rangesIndex = 0;
+	Ranges vec = _ranges;
+	user_addr_t addr;
+
+	// Find starting address within the vector of ranges
+	for (;;) {
+	    getAddrLenForInd(addr, length, type, vec, rangesIndex);
+	    if (offset < length)
+		break;
+	    offset -= length; // (make offset relative)
+	    rangesIndex++;
+	} 
+
+	// Now that we have the starting range,
+	// lets find the last contiguous range
+        addr   += offset;
+        length -= offset;
+
+        for ( ++rangesIndex; rangesIndex < _rangesCount; rangesIndex++ ) {
+	    user_addr_t      newAddr;
+	    IOPhysicalLength newLen;
+
+	    getAddrLenForInd(newAddr, newLen, type, vec, rangesIndex);
+	    if (addr + length != newAddr)
+		break;
+	    length += newLen;
+	} 
+        if (addr)
+	    address = (IOPhysicalAddress) addr;	// Truncate address to 32bit
+	else
+	    length = 0;
+    }
+
+    if ( lengthOfSegment )  *lengthOfSegment = length;
+
+    return address;
+}
+
+/* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
+/* DEPRECATED */ void * IOGeneralMemoryDescriptor::getVirtualSegment(IOByteCount offset,
+/* DEPRECATED */ 							IOByteCount * lengthOfSegment)
+/* DEPRECATED */ {
+                    if (_task == kernel_task)
+                        return (void *) getSourceSegment(offset, lengthOfSegment);
+                    else
+                        panic("IOGMD::getVirtualSegment deprecated");
+
+                    return 0;
+/* DEPRECATED */ }
+/* DEPRECATED */ /* USE INSTEAD: map(), readBytes(), writeBytes() */
+
+
+
+IOReturn 
+IOMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
+{
+    if (kIOMDGetCharacteristics == op) {
+	if (dataSize < sizeof(IOMDDMACharacteristics))
+	    return kIOReturnUnderrun;
+
+	IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
+	data->fLength = getLength();
+	data->fSGCount = 0;
+	data->fDirection = _direction;
+	if (IOMapper::gSystem)
+	    data->fIsMapped = true;
+	data->fIsPrepared = true;	// Assume prepared - fails safe
+    }
+    else if (kIOMDWalkSegments & op) {
+	if (dataSize < sizeof(IOMDDMAWalkSegmentArgs))
+	    return kIOReturnUnderrun;
+
+	IOMDDMAWalkSegmentArgs *data = (IOMDDMAWalkSegmentArgs *) vData;
+	IOByteCount offset  = (IOByteCount) data->fOffset;
+
+	IOPhysicalLength length;
+	IOMemoryDescriptor *ncmd = const_cast<IOMemoryDescriptor *>(this);
+	if (data->fMapped && IOMapper::gSystem)
+	    data->fIOVMAddr = ncmd->getPhysicalSegment(offset, &length);
+	else
+	    data->fIOVMAddr = ncmd->getPhysicalSegment64(offset, &length);
+	data->fLength = length;
+    }
+    else
+	return kIOReturnBadArgument;
+
+    return kIOReturnSuccess;
+}
+
+IOReturn IOMemoryDescriptor::setPurgeable( IOOptionBits newState,
+                                           IOOptionBits * oldState )
+{
+    IOReturn	  err = kIOReturnSuccess;
+    vm_purgable_t control;
+    int           state;
+
+    do 
+    {
+        if (!_memEntry)
+        {
+            err = kIOReturnNotReady;
+            break;
+        }
+
+        control = VM_PURGABLE_SET_STATE;
+        switch (newState)
+        {
+            case kIOMemoryPurgeableKeepCurrent:
+                control = VM_PURGABLE_GET_STATE;
+                break;
+
+            case kIOMemoryPurgeableNonVolatile:
+                state = VM_PURGABLE_NONVOLATILE;
+                break;
+            case kIOMemoryPurgeableVolatile:
+                state = VM_PURGABLE_VOLATILE;
+                break;
+            case kIOMemoryPurgeableEmpty:
+                state = VM_PURGABLE_EMPTY;
+                break;
+            default:
+                err = kIOReturnBadArgument;
+                break;
+        }
+
+        if (kIOReturnSuccess != err)
+            break;
+
+        err = mach_memory_entry_purgable_control((ipc_port_t) _memEntry, control, &state);
+
+        if (oldState)
+        {
+            if (kIOReturnSuccess == err)
+            {
+                switch (state)
+                {
+                    case VM_PURGABLE_NONVOLATILE:
+                        state = kIOMemoryPurgeableNonVolatile;
+                        break;
+                    case VM_PURGABLE_VOLATILE:
+                        state = kIOMemoryPurgeableVolatile;
+                        break;
+                    case VM_PURGABLE_EMPTY:
+                        state = kIOMemoryPurgeableEmpty;
+                        break;
+                    default:
+                        state = kIOMemoryPurgeableNonVolatile;
+                        err = kIOReturnNotReady;
+                        break;
+                }
+                *oldState = state;
+            }
+        }
+    }
+    while (false);
+
+    return (err);
+}
+
+extern "C" void dcache_incoherent_io_flush64(addr64_t pa, unsigned int count);
+extern "C" void dcache_incoherent_io_store64(addr64_t pa, unsigned int count);
+
+IOReturn IOMemoryDescriptor::performOperation( IOOptionBits options,
+                                                IOByteCount offset, IOByteCount length )
+{
+    IOByteCount remaining;
+    void (*func)(addr64_t pa, unsigned int count) = 0;
+
+    switch (options)
+    {
+        case kIOMemoryIncoherentIOFlush:
+            func = &dcache_incoherent_io_flush64;
+            break;
+        case kIOMemoryIncoherentIOStore:
+            func = &dcache_incoherent_io_store64;
+            break;
+    }
+
+    if (!func)
+        return (kIOReturnUnsupported);
+
+    remaining = length = min(length, getLength() - offset);
+    while (remaining)
+    // (process another target segment?)
+    {
+        addr64_t    dstAddr64;
+        IOByteCount dstLen;
+
+        dstAddr64 = getPhysicalSegment64(offset, &dstLen);
+        if (!dstAddr64)
+            break;
+
+        // Clip segment length to remaining
+        if (dstLen > remaining)
+            dstLen = remaining;
+
+	(*func)(dstAddr64, dstLen);
+
+        offset    += dstLen;
+        remaining -= dstLen;
+    }
+
+    return (remaining ? kIOReturnUnderrun : kIOReturnSuccess);
+}
+
+#if	defined(__ppc__) || defined(__arm__)
+extern vm_offset_t		static_memory_end;
+#define io_kernel_static_end	static_memory_end
+#else
+extern vm_offset_t		first_avail;
+#define io_kernel_static_end	first_avail
+#endif
+
+static kern_return_t
+io_get_kernel_static_upl(
+	vm_map_t		/* map */,
+	vm_address_t		offset,
+	vm_size_t		*upl_size,
+	upl_t			*upl,
+	upl_page_info_array_t	page_list,
+	unsigned int		*count,
+	ppnum_t			*highest_page)
+{
+    unsigned int pageCount, page;
+    ppnum_t phys;
+    ppnum_t highestPage = 0;
+
+    pageCount = atop_32(*upl_size);
+    if (pageCount > *count)
+	pageCount = *count;
+
+    *upl = NULL;
+
+    for (page = 0; page < pageCount; page++)
+    {
+	phys = pmap_find_phys(kernel_pmap, ((addr64_t)offset) + ptoa_64(page));
+	if (!phys)
 	    break;
+	page_list[page].phys_addr = phys;
+	page_list[page].pageout	  = 0;
+	page_list[page].absent	  = 0;
+	page_list[page].dirty	  = 0;
+	page_list[page].precious  = 0;
+	page_list[page].device	  = 0;
+	if (phys > highestPage)
+	    highestPage = page;
+    }
+
+    *highest_page = highestPage;
+
+    return ((page >= pageCount) ? kIOReturnSuccess : kIOReturnVMError);
+}
+
+IOReturn IOGeneralMemoryDescriptor::wireVirtual(IODirection forDirection)
+{
+    IOOptionBits type = _flags & kIOMemoryTypeMask;
+    IOReturn error = kIOReturnCannotWire;
+    ioGMDData *dataP;
+    ppnum_t mapBase = 0;
+    IOMapper *mapper;
+    ipc_port_t sharedMem = (ipc_port_t) _memEntry;
+
+    assert(!_wireCount);
+    assert(kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type);
+
+    if (_pages >= gIOMaximumMappedIOPageCount)
+	return kIOReturnNoResources;
+
+    dataP = getDataP(_memoryEntries);
+    mapper = dataP->fMapper;
+    if (mapper && _pages)
+        mapBase = mapper->iovmAlloc(_pages);
+
+    // Note that appendBytes(NULL) zeros the data up to the
+    // desired length.
+    _memoryEntries->appendBytes(0, dataP->fPageCnt * sizeof(upl_page_info_t));
+    dataP = 0;	// May no longer be valid so lets not get tempted.
+
+    if (forDirection == kIODirectionNone)
+        forDirection = _direction;
+
+    int uplFlags;    // This Mem Desc's default flags for upl creation
+    switch (kIODirectionOutIn & forDirection)
+    {
+    case kIODirectionOut:
+        // Pages do not need to be marked as dirty on commit
+        uplFlags = UPL_COPYOUT_FROM;
+        _flags |= kIOMemoryPreparedReadOnly;
+        break;
+
+    case kIODirectionIn:
+    default:
+        uplFlags = 0;	// i.e. ~UPL_COPYOUT_FROM
+        break;
+    }
+    uplFlags |= UPL_SET_IO_WIRE | UPL_SET_LITE;
+
+#ifdef UPL_NEED_32BIT_ADDR
+    if (kIODirectionPrepareToPhys32 & forDirection) 
+	uplFlags |= UPL_NEED_32BIT_ADDR;
+#endif
+
+    // Find the appropriate vm_map for the given task
+    vm_map_t curMap;
+    if (_task == kernel_task && (kIOMemoryBufferPageable & _flags))
+        curMap = 0;
+    else
+        { curMap = get_task_map(_task); }
+
+    // Iterate over the vector of virtual ranges
+    Ranges vec = _ranges;
+    unsigned int pageIndex = 0;
+    IOByteCount mdOffset = 0;
+    ppnum_t highestPage = 0;
+    for (UInt range = 0; range < _rangesCount; range++) {
+        ioPLBlock iopl;
+	user_addr_t startPage;
+        IOByteCount numBytes;
+	ppnum_t highPage = 0;
+
+	// Get the startPage address and length of vec[range]
+	getAddrLenForInd(startPage, numBytes, type, vec, range);
+	iopl.fPageOffset = (short) startPage & PAGE_MASK;
+	numBytes += iopl.fPageOffset;
+	startPage = trunc_page_64(startPage);
+
+	if (mapper)
+	    iopl.fMappedBase = mapBase + pageIndex;
+	else
+	    iopl.fMappedBase = 0;
+
+	// Iterate over the current range, creating UPLs
+        while (numBytes) {
+            dataP = getDataP(_memoryEntries);
+	    vm_address_t kernelStart = (vm_address_t) startPage;
+            vm_map_t theMap;
+	    if (curMap)
+		theMap = curMap;
+	    else if (!sharedMem) {
+		assert(_task == kernel_task);
+		theMap = IOPageableMapForAddress(kernelStart);
+	    }
+	    else
+		theMap = NULL;
+
+            upl_page_info_array_t pageInfo = getPageList(dataP);
+            int ioplFlags = uplFlags;
+            upl_page_list_ptr_t baseInfo = &pageInfo[pageIndex];
+
+            vm_size_t ioplSize = round_page_32(numBytes);
+            unsigned int numPageInfo = atop_32(ioplSize);
+
+	    if (theMap == kernel_map && kernelStart < io_kernel_static_end) {
+		error = io_get_kernel_static_upl(theMap, 
+						kernelStart,
+						&ioplSize,
+						&iopl.fIOPL,
+						baseInfo,
+						&numPageInfo,
+						&highPage);
+	    }
+	    else if (sharedMem) {
+		error = memory_object_iopl_request(sharedMem, 
+						ptoa_32(pageIndex),
+						&ioplSize,
+						&iopl.fIOPL,
+						baseInfo,
+						&numPageInfo,
+						&ioplFlags);
+	    }
+	    else {
+		assert(theMap);
+		error = vm_map_create_upl(theMap,
+						startPage,
+						&ioplSize,
+						&iopl.fIOPL,
+						baseInfo,
+						&numPageInfo,
+						&ioplFlags);
+	    }
+
+            assert(ioplSize);
+            if (error != KERN_SUCCESS)
+                goto abortExit;
+
+	    if (iopl.fIOPL)
+		highPage = upl_get_highest_page(iopl.fIOPL);
+	    if (highPage > highestPage)
+		highestPage = highPage;
+
+            error = kIOReturnCannotWire;
+
+            if (baseInfo->device) {
+                numPageInfo = 1;
+                iopl.fFlags  = kIOPLOnDevice;
+                // Don't translate device memory at all 
+		if (mapper && mapBase) {
+		    mapper->iovmFree(mapBase, _pages);
+		    mapBase = 0;
+		    iopl.fMappedBase = 0;
+		}
+            }
+            else {
+                iopl.fFlags = 0;
+		if (mapper)
+                    mapper->iovmInsert(mapBase, pageIndex,
+                                       baseInfo, numPageInfo);
+            }
+
+            iopl.fIOMDOffset = mdOffset;
+            iopl.fPageInfo = pageIndex;
+
+	    if ((_flags & kIOMemoryAutoPrepare) && iopl.fIOPL)
+	    {
+		upl_commit(iopl.fIOPL, 0, 0);
+		upl_deallocate(iopl.fIOPL);
+		iopl.fIOPL = 0;
+	    }
+
+            if (!_memoryEntries->appendBytes(&iopl, sizeof(iopl))) {
+                // Clean up partial created and unsaved iopl
+                if (iopl.fIOPL) {
+                    upl_abort(iopl.fIOPL, 0);
+                    upl_deallocate(iopl.fIOPL);
+                }
+                goto abortExit;
+            }
+
+            // Check for a multiple iopl's in one virtual range
+            pageIndex += numPageInfo;
+            mdOffset -= iopl.fPageOffset;
+            if (ioplSize < numBytes) {
+                numBytes -= ioplSize;
+                startPage += ioplSize;
+                mdOffset += ioplSize;
+                iopl.fPageOffset = 0;
+		if (mapper)
+		    iopl.fMappedBase = mapBase + pageIndex;
+            }
+            else {
+                mdOffset += numBytes;
+                break;
+            }
+        }
+    }
+
+    _highestPage = highestPage;
+
+    return kIOReturnSuccess;
+
+abortExit:
+    {
+        dataP = getDataP(_memoryEntries);
+        UInt done = getNumIOPL(_memoryEntries, dataP);
+        ioPLBlock *ioplList = getIOPLList(dataP);
+    
+        for (UInt range = 0; range < done; range++)
+	{
+	    if (ioplList[range].fIOPL) {
+             upl_abort(ioplList[range].fIOPL, 0);
+             upl_deallocate(ioplList[range].fIOPL);
+	    }
 	}
-        bytesLeft -= segmentLength;
-	offset += segmentLength;
-	setPosition(offset);
-    }
-#else
-    while (bytesLeft && (segment = getVirtualSegment(offset, &segmentLength)))
-    {
-        segmentLength = min(segmentLength, bytesLeft);
-        bcopy(/* from */ segment, /* to */ bytes, /* size */ segmentLength);
-        bytesLeft -= segmentLength;
-	offset += segmentLength;
-        bytes = (void *) (((UInt32) bytes) + segmentLength);
-    }
-#endif
-
-    return withLength - bytesLeft;
-}
-
-/*
- * writeBytes:
- *
- * Copy data to the memory descriptor's buffer from the specified buffer,
- * relative to the current position.  The memory descriptor's position is
- * advanced based on the number of bytes copied.
- */
-IOByteCount IOGeneralMemoryDescriptor::writeBytes(IOByteCount offset,
-				const void* bytes,IOByteCount withLength)
-{
-    IOByteCount bytesLeft;
-    void *    segment;
-    IOByteCount segmentLength;
-
-    if( offset != _position)
-	setPosition( offset );
-
-    withLength = min(withLength, _length - _position);
-    bytesLeft  = withLength;
-
-#if 0
-    while (bytesLeft && (_position < _length))
-    {
-	assert(_position <= _length);
-
-	/* Compute the relative length to the end of this virtual segment. */
-        segmentLength = min(_ranges.v[_positionAtIndex].length - _positionAtOffset, bytesLeft);
-
-	/* Compute the relative address of this virtual segment. */
-        segment = (void *)(_ranges.v[_positionAtIndex].address + _positionAtOffset);
-
-	if (KERN_SUCCESS != vm_map_write_user(getMapForTask(_task, segment),
-		/* from */ (vm_offset_t) bytes, 
-	        /* to */ (vm_offset_t) segment,
-		/* size */ segmentLength))
-	{
-	    assert( false );
-            bytesLeft = withLength;
-	    break;
-	}
-        bytesLeft -= segmentLength;
-	offset += segmentLength;
-	setPosition(offset);
-    }
-#else
-    while (bytesLeft && (segment = getVirtualSegment(offset, &segmentLength)))
-    {
-        segmentLength = min(segmentLength, bytesLeft);
-        bcopy(/* from */ bytes, /* to */ segment, /* size */ segmentLength);
-        // Flush cache in case we're copying code around, eg. handling a code page fault
-        IOFlushProcessorCache(kernel_task, (vm_offset_t) segment, segmentLength );
-        
-        bytesLeft -= segmentLength;
-        offset += segmentLength;
-        bytes = (void *) (((UInt32) bytes) + segmentLength);
-    }
-#endif
-
-    return withLength - bytesLeft;
-}
-
-/*
- * getPhysicalSegment:
- *
- * Get the physical address of the buffer, relative to the current position.
- * If the current position is at the end of the buffer, a zero is returned.
- */
-IOPhysicalAddress
-IOGeneralMemoryDescriptor::getPhysicalSegment(IOByteCount offset,
-						IOByteCount * lengthOfSegment)
-{
-    vm_address_t      virtualAddress;
-    IOByteCount       virtualLength;
-    pmap_t            virtualPMap;
-    IOPhysicalAddress physicalAddress;
-    IOPhysicalLength  physicalLength;
-
-    if( kIOMemoryRequiresWire & _flags)
-        assert( _wireCount );
-
-    if ((0 == _task) && (1 == _rangesCount))
-    {
-	assert(offset <= _length);
-	if (offset >= _length)
-	{
-	    physicalAddress = 0;
-	    physicalLength  = 0;
-	}
-	else
-	{
-	    physicalLength = _length - offset;
-	    physicalAddress = offset + _ranges.v[0].address;
-	}
-
-	if (lengthOfSegment)
-	    *lengthOfSegment = physicalLength;
-	return physicalAddress;
-    }
-
-    if( offset != _position)
-	setPosition( offset );
-
-    assert(_position <= _length);
-
-    /* Fail gracefully if the position is at (or past) the end-of-buffer. */
-    if (_position >= _length)
-    {
-        *lengthOfSegment = 0;
-        return 0;
-    }
-
-    /* Prepare to compute the largest contiguous physical length possible. */
-
-    virtualAddress  = _ranges.v[_positionAtIndex].address + _positionAtOffset;
-    virtualLength   = _ranges.v[_positionAtIndex].length  - _positionAtOffset;
-    vm_address_t      virtualPage  = trunc_page(virtualAddress);
-    if( _task)
-	virtualPMap     = get_task_pmap(_task);
-    else
-	virtualPMap	= 0;
-
-    physicalAddress = (virtualAddress == _cachedVirtualAddress) ?
-                        _cachedPhysicalAddress :              /* optimization */
-			virtualPMap ?
-                        	pmap_extract(virtualPMap, virtualAddress) :
-				virtualAddress;
-    physicalLength  = trunc_page(physicalAddress) + page_size - physicalAddress;
-
-    if (!physicalAddress && _task)
-    {
-	physicalAddress =
-	    vm_map_get_phys_page(get_task_map(_task), virtualPage);
-	physicalAddress += virtualAddress - virtualPage;
-    }
-
-    if (physicalAddress == 0)     /* memory must be wired in order to proceed */
-    {
-        assert(physicalAddress);
-        *lengthOfSegment = 0;
-        return 0;
-    }
-
-    /* Compute the largest contiguous physical length possible, within range. */
-    IOPhysicalAddress physicalPage = trunc_page(physicalAddress);
-
-    while (physicalLength < virtualLength)
-    {
-        physicalPage          += page_size;
-        virtualPage           += page_size;
-        _cachedVirtualAddress  = virtualPage;
-        _cachedPhysicalAddress = virtualPMap ?
-                        		pmap_extract(virtualPMap, virtualPage) :
-					virtualPage;
-	if (!_cachedPhysicalAddress && _task)
-	{
-	    _cachedPhysicalAddress =
-		vm_map_get_phys_page(get_task_map(_task), virtualPage);
-	}
-
-        if (_cachedPhysicalAddress != physicalPage)  break;
-
-        physicalLength += page_size;
-    }
-
-    /* Clip contiguous physical length at the end of this range. */
-    if (physicalLength > virtualLength)
-        physicalLength = virtualLength;
-
-    if( lengthOfSegment)
-	*lengthOfSegment = physicalLength;
-
-    return physicalAddress;
-}
-
-
-/*
- * getVirtualSegment:
- *
- * Get the virtual address of the buffer, relative to the current position.
- * If the memory wasn't mapped into the caller's address space, it will be
- * mapped in now.   If the current position is at the end of the buffer, a
- * null is returned.
- */
-void * IOGeneralMemoryDescriptor::getVirtualSegment(IOByteCount offset,
-							IOByteCount * lengthOfSegment)
-{
-    if( offset != _position)
-	setPosition( offset );
-
-    assert(_position <= _length);
-
-    /* Fail gracefully if the position is at (or past) the end-of-buffer. */
-    if (_position >= _length)
-    {
-        *lengthOfSegment = 0;
-        return 0;
-    }
-
-    /* Compute the relative length to the end of this virtual segment. */
-    *lengthOfSegment = _ranges.v[_positionAtIndex].length - _positionAtOffset;
-
-    /* Compute the relative address of this virtual segment. */
-    if (_task == kernel_task)
-        return (void *)(_ranges.v[_positionAtIndex].address + _positionAtOffset);
-    else
-    {
-	vm_offset_t off;
-
-        mapIntoKernel(_positionAtIndex);
-
-	off  = _ranges.v[_kernPtrAtIndex].address;
-	off -= trunc_page(off);
-
-	return (void *) (_kernPtrAligned + off + _positionAtOffset);
-    }
+	(void) _memoryEntries->initWithBytes(dataP, sizeof(ioGMDData)); // == setLength()
+
+        if (mapper && mapBase)
+            mapper->iovmFree(mapBase, _pages);
+    }
+
+    if (error == KERN_FAILURE)
+        error = kIOReturnCannotWire;
+
+    return error;
 }
 
 /*
@@ -776,137 +2010,29 @@
  * the memory after the I/O transfer finishes.  This method needn't
  * called for non-pageable memory.
  */
-IOReturn IOGeneralMemoryDescriptor::prepare(
-		IODirection forDirection = kIODirectionNone)
-{
-    UInt rangeIndex = 0;
-
-    if((_wireCount == 0) && (kIOMemoryRequiresWire & _flags)) {
-        kern_return_t rc;
-
-        if(forDirection == kIODirectionNone)
-            forDirection = _direction;
-
-        vm_prot_t access = VM_PROT_DEFAULT;    // Could be cleverer using direction
-
-        //
-        // Check user read/write access to the data buffer.
-        //
-
-        for (rangeIndex = 0; rangeIndex < _rangesCount; rangeIndex++)
-        {
-            vm_offset_t checkBase = trunc_page(_ranges.v[rangeIndex].address);
-            vm_size_t   checkSize = round_page(_ranges.v[rangeIndex].length );
-
-            while (checkSize)
-            {
-                vm_region_basic_info_data_t regionInfo;
-                mach_msg_type_number_t      regionInfoSize = sizeof(regionInfo);
-                vm_size_t                   regionSize;
-
-                if ( (vm_region(
-                          /* map         */ getMapForTask(_task, checkBase),
-                          /* address     */ &checkBase,
-                          /* size        */ &regionSize,
-                          /* flavor      */ VM_REGION_BASIC_INFO,
-                          /* info        */ (vm_region_info_t) &regionInfo,
-                          /* info size   */ &regionInfoSize,
-                          /* object name */ 0 ) != KERN_SUCCESS             ) ||
-                     ( (forDirection & kIODirectionIn ) &&
-                                   !(regionInfo.protection & VM_PROT_WRITE) ) ||
-                     ( (forDirection & kIODirectionOut) && 
-                                   !(regionInfo.protection & VM_PROT_READ ) ) )
-                {
-                    return kIOReturnVMError;
-                }
-
-                assert((regionSize & PAGE_MASK) == 0);
-
-                regionSize = min(regionSize, checkSize);
-                checkSize -= regionSize;
-                checkBase += regionSize;
-            } // (for each vm region)
-        } // (for each io range)
-
-        for (rangeIndex = 0; rangeIndex < _rangesCount; rangeIndex++) {
-
-            vm_offset_t srcAlign = trunc_page(_ranges.v[rangeIndex].address);
-            IOByteCount srcAlignEnd = trunc_page(_ranges.v[rangeIndex].address +
-                                _ranges.v[rangeIndex].length  +
-                                page_size - 1);
-
-	    vm_map_t taskVMMap = getMapForTask(_task, srcAlign);
-
-            rc = vm_map_wire(taskVMMap, srcAlign, srcAlignEnd, access, FALSE);
-	    if (KERN_SUCCESS != rc) {
-		IOLog("IOMemoryDescriptor::prepare vm_map_wire failed: %d\n", rc);
-		goto abortExit;
-	    }
-
-	    // If this I/O is for a user land task then protect ourselves
-	    // against COW and other vm_shenanigans
-	    if (_task && _task != kernel_task) {
-		// setup a data object to hold the 'named' memory regions
-		// @@@ gvdl: If we fail to allocate an OSData we will just
-		// hope for the best for the time being.  Lets not fail a
-		// prepare at this late stage in product release.
-		if (!_memoryEntries)
-		    _memoryEntries = OSData::withCapacity(16);
-		if (_memoryEntries) {
-		    vm_object_offset_t desiredSize = srcAlignEnd - srcAlign;
-		    vm_object_offset_t entryStart = srcAlign;
-		    ipc_port_t memHandle;
-
-		    do {
-			vm_object_offset_t actualSize = desiredSize;
-
-			rc = mach_make_memory_entry_64
-			    (taskVMMap, &actualSize, entryStart,
-			    forDirection, &memHandle, NULL);
-			if (KERN_SUCCESS != rc) {
-			    IOLog("IOMemoryDescriptor::prepare mach_make_memory_entry_64 failed: %d\n", rc);
-			    goto abortExit;
-			}
-
-			_memoryEntries->
-			    appendBytes(&memHandle, sizeof(memHandle));
-			desiredSize -= actualSize;
-			entryStart += actualSize;
-		    } while (desiredSize);
-		}
-	    }
-        }
-    }
-    _wireCount++;
-    return kIOReturnSuccess;
-
-abortExit:
-    UInt doneIndex;
-
-
-    for(doneIndex = 0; doneIndex < rangeIndex; doneIndex++) {
-	vm_offset_t srcAlign = trunc_page(_ranges.v[doneIndex].address);
-	IOByteCount srcAlignEnd = trunc_page(_ranges.v[doneIndex].address +
-			    _ranges.v[doneIndex].length  +
-			    page_size - 1);
-
-	vm_map_unwire(getMapForTask(_task, srcAlign), srcAlign,
-			    srcAlignEnd, FALSE);
-    }
-
-    if (_memoryEntries) {
-	ipc_port_t *handles, *handlesEnd;
-
-	handles = (ipc_port_t *) _memoryEntries->getBytesNoCopy();
-	handlesEnd = (ipc_port_t *)
-	    ((vm_address_t) handles + _memoryEntries->getLength());
-	while (handles < handlesEnd)
-	    ipc_port_release_send(*handles++);
-	_memoryEntries->release();
-	_memoryEntries = 0;
-    }
-
-    return kIOReturnVMError;
+IOReturn IOGeneralMemoryDescriptor::prepare(IODirection forDirection)
+{
+    IOReturn error    = kIOReturnSuccess;
+    IOOptionBits type = _flags & kIOMemoryTypeMask;
+
+    if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type))
+	return kIOReturnSuccess;
+
+    if (_prepareLock)
+	IOLockLock(_prepareLock);
+
+    if (!_wireCount
+    && (kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type) ) {
+        error = wireVirtual(forDirection);
+    }
+
+    if (kIOReturnSuccess == error)
+	_wireCount++;
+
+    if (_prepareLock)
+	IOLockUnlock(_prepareLock);
+
+    return error;
 }
 
 /*
@@ -918,482 +2044,782 @@
  * before and after an I/O transfer involving pageable memory.
  */
  
-IOReturn IOGeneralMemoryDescriptor::complete(
-		IODirection forDirection = kIODirectionNone)
-{
+IOReturn IOGeneralMemoryDescriptor::complete(IODirection /* forDirection */)
+{
+    IOOptionBits type = _flags & kIOMemoryTypeMask;
+
+    if ((kIOMemoryTypePhysical == type) || (kIOMemoryTypePhysical64 == type))
+	return kIOReturnSuccess;
+
+    if (_prepareLock)
+	IOLockLock(_prepareLock);
+
     assert(_wireCount);
 
-    if(0 == _wireCount)
-        return kIOReturnSuccess;
-
-    _wireCount--;
-    if((_wireCount == 0) && (kIOMemoryRequiresWire & _flags)) {
-        UInt rangeIndex;
-        kern_return_t rc;
-
-        if(forDirection == kIODirectionNone)
-            forDirection = _direction;
-
-        for(rangeIndex = 0; rangeIndex < _rangesCount; rangeIndex++) {
-
-            vm_offset_t srcAlign = trunc_page(_ranges.v[rangeIndex].address);
-            IOByteCount srcAlignEnd = trunc_page(_ranges.v[rangeIndex].address +
-                                _ranges.v[rangeIndex].length  +
-                                page_size - 1);
-
-            if(forDirection == kIODirectionIn)
-                pmap_modify_pages(get_task_pmap(_task), srcAlign, srcAlignEnd);
-
-            rc = vm_map_unwire(getMapForTask(_task, srcAlign), srcAlign,
-                                  srcAlignEnd, FALSE);
-            if(rc != KERN_SUCCESS)
-                IOLog("IOMemoryDescriptor::complete: vm_map_unwire failed: %d\n", rc);
-        }
-
-	if (_memoryEntries) {
-	    ipc_port_t *handles, *handlesEnd;
-
-	    handles = (ipc_port_t *) _memoryEntries->getBytesNoCopy();
-	    handlesEnd = (ipc_port_t *)
-			((vm_address_t) handles + _memoryEntries->getLength());
-	    while (handles < handlesEnd)
-		ipc_port_release_send(*handles++);
-
-	    _memoryEntries->release();
-	    _memoryEntries = 0;
+    if (_wireCount)
+    {
+	_wireCount--;
+	if (!_wireCount)
+	{
+	    IOOptionBits type = _flags & kIOMemoryTypeMask;
+	    ioGMDData * dataP = getDataP(_memoryEntries);
+	    ioPLBlock *ioplList = getIOPLList(dataP);
+	    UInt count = getNumIOPL(_memoryEntries, dataP);
+
+	    if (dataP->fMapper && _pages && ioplList[0].fMappedBase)
+		dataP->fMapper->iovmFree(ioplList[0].fMappedBase, _pages);
+
+	    // Only complete iopls that we created which are for TypeVirtual
+	    if (kIOMemoryTypeVirtual == type || kIOMemoryTypeVirtual64 == type || kIOMemoryTypeUIO == type) {
+		for (UInt ind = 0; ind < count; ind++)
+		    if (ioplList[ind].fIOPL) {
+			 upl_commit(ioplList[ind].fIOPL, 0, 0);
+			 upl_deallocate(ioplList[ind].fIOPL);
+		    }
+	    }
+	    (void) _memoryEntries->initWithBytes(dataP, sizeof(ioGMDData)); // == setLength()
 	}
-
-	_cachedVirtualAddress = 0;
-    }
+    }
+
+    if (_prepareLock)
+	IOLockUnlock(_prepareLock);
+
     return kIOReturnSuccess;
 }
 
 IOReturn IOGeneralMemoryDescriptor::doMap(
+	vm_map_t		__addressMap,
+	IOVirtualAddress *	__address,
+	IOOptionBits		options,
+	IOByteCount		__offset,
+	IOByteCount		__length )
+
+{
+    if (!(kIOMap64Bit & options)) panic("IOGeneralMemoryDescriptor::doMap !64bit");
+
+    _IOMemoryMap * mapping = (_IOMemoryMap *) *__address;
+    mach_vm_size_t offset  = mapping->fOffset + __offset;
+    mach_vm_size_t length  = mapping->fLength;
+
+    kern_return_t kr;
+    ipc_port_t sharedMem = (ipc_port_t) _memEntry;
+
+    IOOptionBits type = _flags & kIOMemoryTypeMask;
+    Ranges vec = _ranges;
+
+    user_addr_t range0Addr = 0;
+    IOByteCount range0Len = 0;
+
+    if (vec.v)
+	getAddrLenForInd(range0Addr, range0Len, type, vec, 0);
+
+    // mapping source == dest? (could be much better)
+    if( _task
+     && (mapping->fAddressMap == get_task_map(_task)) && (options & kIOMapAnywhere)
+     && (1 == _rangesCount) && (0 == offset)
+     && range0Addr && (length <= range0Len) )
+    {
+	mapping->fAddress = range0Addr;
+	mapping->fOptions |= kIOMapStatic;
+
+	return( kIOReturnSuccess );
+    }
+
+    if( 0 == sharedMem) {
+
+        vm_size_t size = ptoa_32(_pages);
+
+        if( _task) {
+
+            memory_object_size_t actualSize = size;
+	    vm_prot_t            prot       = VM_PROT_READ;
+	    if (!(kIOMapReadOnly & options))
+		prot |= VM_PROT_WRITE;
+	    else if (kIOMapDefaultCache != (options & kIOMapCacheMask))
+		prot |= VM_PROT_WRITE;
+
+            kr = mach_make_memory_entry_64(get_task_map(_task),
+                        &actualSize, range0Addr,
+                        prot, &sharedMem,
+                        NULL );
+
+            if( (KERN_SUCCESS == kr) && (actualSize != round_page_32(size))) {
+#if IOASSERT
+                IOLog("mach_make_memory_entry_64 (%08llx) size (%08lx:%08x)\n",
+                            range0Addr, (UInt32) actualSize, size);
+#endif
+                kr = kIOReturnVMError;
+                ipc_port_release_send( sharedMem );
+            }
+
+            if( KERN_SUCCESS != kr)
+                sharedMem = MACH_PORT_NULL;
+
+        } else do {	// _task == 0, must be physical
+
+            memory_object_t 	pager;
+	    unsigned int    	flags = 0;
+    	    addr64_t		pa;
+    	    IOPhysicalLength	segLen;
+
+	    pa = getPhysicalSegment64( offset, &segLen );
+
+            if( !reserved) {
+                reserved = IONew( ExpansionData, 1 );
+                if( !reserved)
+                    continue;
+            }
+            reserved->pagerContig = (1 == _rangesCount);
+	    reserved->memory = this;
+
+	    /*What cache mode do we need*/
+            switch(options & kIOMapCacheMask ) {
+
+		case kIOMapDefaultCache:
+		default:
+		    flags = IODefaultCacheBits(pa);
+		    if (DEVICE_PAGER_CACHE_INHIB & flags)
+		    {
+			if (DEVICE_PAGER_GUARDED & flags)
+			    mapping->fOptions |= kIOMapInhibitCache;
+			else
+			    mapping->fOptions |= kIOMapWriteCombineCache;
+		    }
+		    else if (DEVICE_PAGER_WRITE_THROUGH & flags)
+			mapping->fOptions |= kIOMapWriteThruCache;
+		    else
+			mapping->fOptions |= kIOMapCopybackCache;
+		    break;
+	
+		case kIOMapInhibitCache:
+		    flags = DEVICE_PAGER_CACHE_INHIB | 
+				    DEVICE_PAGER_COHERENT | DEVICE_PAGER_GUARDED;
+		    break;
+	
+		case kIOMapWriteThruCache:
+		    flags = DEVICE_PAGER_WRITE_THROUGH |
+				    DEVICE_PAGER_COHERENT | DEVICE_PAGER_GUARDED;
+		    break;
+
+		case kIOMapCopybackCache:
+		    flags = DEVICE_PAGER_COHERENT;
+		    break;
+
+		case kIOMapWriteCombineCache:
+		    flags = DEVICE_PAGER_CACHE_INHIB |
+				    DEVICE_PAGER_COHERENT;
+		    break;
+            }
+
+	    flags |= reserved->pagerContig ? DEVICE_PAGER_CONTIGUOUS : 0;
+
+            pager = device_pager_setup( (memory_object_t) 0, (int) reserved, 
+								size, flags);
+            assert( pager );
+
+            if( pager) {
+                kr = mach_memory_object_memory_entry_64( (host_t) 1, false /*internal*/, 
+                            size, VM_PROT_READ | VM_PROT_WRITE, pager, &sharedMem );
+
+                assert( KERN_SUCCESS == kr );
+                if( KERN_SUCCESS != kr)
+		{
+		    device_pager_deallocate( pager );
+                    pager = MACH_PORT_NULL;
+                    sharedMem = MACH_PORT_NULL;
+                }
+            }
+	    if( pager && sharedMem)
+		reserved->devicePager    = pager;
+	    else {
+		IODelete( reserved, ExpansionData, 1 );
+		reserved = 0;
+	    }
+
+        } while( false );
+
+        _memEntry = (void *) sharedMem;
+    }
+
+    IOReturn result;
+    if (0 == sharedMem)
+      result = kIOReturnVMError;
+    else
+      result = super::doMap( __addressMap, __address,
+					options, __offset, __length );
+
+    return( result );
+}
+
+IOReturn IOGeneralMemoryDescriptor::doUnmap(
 	vm_map_t		addressMap,
-	IOVirtualAddress *	atAddress,
-	IOOptionBits		options,
-	IOByteCount		sourceOffset = 0,
-	IOByteCount		length = 0 )
-{
-    kern_return_t kr;
-
-    // mapping source == dest? (could be much better)
-    if( _task && (addressMap == get_task_map(_task)) && (options & kIOMapAnywhere)
-	&& (1 == _rangesCount) && (0 == sourceOffset)
-	&& (length <= _ranges.v[0].length) ) {
-	    *atAddress = _ranges.v[0].address;
-	    return( kIOReturnSuccess );
-    }
-
-     if( _task && _memEntry && (_flags & kIOMemoryRequiresWire)) {
-
-        do {
-
-            if( (1 != _rangesCount)
-             || (kIOMapDefaultCache != (options & kIOMapCacheMask)) ) {
-                kr = kIOReturnUnsupported;
+	IOVirtualAddress	__address,
+	IOByteCount		__length )
+{
+    return (super::doUnmap(addressMap, __address, __length));
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+OSDefineMetaClassAndAbstractStructors( IOMemoryMap, OSObject )
+
+/* inline function implementation */
+IOPhysicalAddress IOMemoryMap::getPhysicalAddress()
+    { return( getPhysicalSegment( 0, 0 )); }
+
+
+#undef super
+#define super IOMemoryMap
+
+OSDefineMetaClassAndStructors(_IOMemoryMap, IOMemoryMap)
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+bool _IOMemoryMap::init(
+        task_t			intoTask,
+        mach_vm_address_t	toAddress,
+        IOOptionBits		_options,
+        mach_vm_size_t		_offset,
+        mach_vm_size_t		_length )
+{
+    if (!intoTask)
+	return( false);
+
+    if (!super::init())
+	return(false);
+
+    fAddressMap  = get_task_map(intoTask);
+    if (!fAddressMap)
+	return(false);
+    vm_map_reference(fAddressMap);
+
+    fAddressTask = intoTask;
+    fOptions     = _options;
+    fLength      = _length;
+    fOffset	 = _offset;
+    fAddress     = toAddress;
+
+    return (true);
+}
+
+bool _IOMemoryMap::setMemoryDescriptor(IOMemoryDescriptor * _memory, mach_vm_size_t _offset)
+{
+    if (!_memory)
+	return(false);
+
+    if (!fSuperMap)
+    {
+	if( (_offset + fLength) > _memory->getLength())
+	    return( false);
+	fOffset = _offset;
+    }
+
+    _memory->retain();
+    if (fMemory)
+    {
+	if (fMemory != _memory)
+	    fMemory->removeMapping(this);
+	fMemory->release();
+    }
+    fMemory = _memory;
+
+    return( true );
+}
+
+struct IOMemoryDescriptorMapAllocRef
+{
+    ipc_port_t		sharedMem;
+    mach_vm_address_t	mapped;
+    mach_vm_size_t	size;
+    mach_vm_size_t	sourceOffset;
+    IOOptionBits	options;
+};
+
+static kern_return_t IOMemoryDescriptorMapAlloc(vm_map_t map, void * _ref)
+{
+    IOMemoryDescriptorMapAllocRef * ref = (IOMemoryDescriptorMapAllocRef *)_ref;
+    IOReturn			    err;
+
+    do {
+        if( ref->sharedMem)
+	{
+            vm_prot_t prot = VM_PROT_READ
+                            | ((ref->options & kIOMapReadOnly) ? 0 : VM_PROT_WRITE);
+
+	    // VM system requires write access to change cache mode
+	    if (kIOMapDefaultCache != (ref->options & kIOMapCacheMask))
+		prot |= VM_PROT_WRITE;
+
+            // set memory entry cache
+            vm_prot_t memEntryCacheMode = prot | MAP_MEM_ONLY;
+            switch (ref->options & kIOMapCacheMask)
+            {
+		case kIOMapInhibitCache:
+                    SET_MAP_MEM(MAP_MEM_IO, memEntryCacheMode);
+                    break;
+	
+		case kIOMapWriteThruCache:
+                    SET_MAP_MEM(MAP_MEM_WTHRU, memEntryCacheMode);
+                    break;
+
+		case kIOMapWriteCombineCache:
+                    SET_MAP_MEM(MAP_MEM_WCOMB, memEntryCacheMode);
+                    break;
+
+		case kIOMapCopybackCache:
+                    SET_MAP_MEM(MAP_MEM_COPYBACK, memEntryCacheMode);
+                    break;
+
+		case kIOMapDefaultCache:
+		default:
+                    SET_MAP_MEM(MAP_MEM_NOOP, memEntryCacheMode);
+                    break;
+            }
+
+            vm_size_t unused = 0;
+
+            err = mach_make_memory_entry( NULL /*unused*/, &unused, 0 /*unused*/, 
+                                            memEntryCacheMode, NULL, ref->sharedMem );
+            if (KERN_SUCCESS != err)
+                IOLog("MAP_MEM_ONLY failed %d\n", err);
+
+            err = mach_vm_map( map,
+                            &ref->mapped,
+                            ref->size, 0 /* mask */, 
+                            (( ref->options & kIOMapAnywhere ) ? VM_FLAGS_ANYWHERE : VM_FLAGS_FIXED)
+                            | VM_MAKE_TAG(VM_MEMORY_IOKIT), 
+                            ref->sharedMem, ref->sourceOffset,
+                            false, // copy
+                            prot, // cur
+                            prot, // max
+                            VM_INHERIT_NONE);
+
+            if( KERN_SUCCESS != err) {
+                ref->mapped = 0;
                 continue;
             }
-
-            if( 0 == length)
-                length = getLength();
-            if( (sourceOffset + length) > _ranges.v[0].length) {
-                kr = kIOReturnBadArgument;
+    
+        }
+	else
+	{
+            err = mach_vm_allocate( map, &ref->mapped, ref->size,
+                            ((ref->options & kIOMapAnywhere) ? VM_FLAGS_ANYWHERE : VM_FLAGS_FIXED)
+                            | VM_MAKE_TAG(VM_MEMORY_IOKIT) );
+            if( KERN_SUCCESS != err) {
+                ref->mapped = 0;
                 continue;
             }
-
-            ipc_port_t sharedMem = (ipc_port_t) _memEntry;
-            vm_prot_t prot = VM_PROT_READ
-                            | ((options & kIOMapReadOnly) ? 0 : VM_PROT_WRITE);
-
-            // vm_map looks for addresses above here, even when VM_FLAGS_ANYWHERE
-            if( options & kIOMapAnywhere)
-                *atAddress = 0;
-
-            if( 0 == sharedMem)
-                kr = kIOReturnVMError;
-            else
-                kr = KERN_SUCCESS;
-
-            if( KERN_SUCCESS == kr)
-                kr = vm_map( addressMap,
-                             atAddress,
-                             length, 0 /* mask */, 
-                             (( options & kIOMapAnywhere ) ? VM_FLAGS_ANYWHERE : VM_FLAGS_FIXED)
-                             | VM_MAKE_TAG(VM_MEMORY_IOKIT), 
-                             sharedMem, sourceOffset,
-                             false, // copy
-                             prot, // cur
-                             prot, // max
-                             VM_INHERIT_NONE);
-        
-        } while( false );
-
-    } else
-        kr = super::doMap( addressMap, atAddress,
-                           options, sourceOffset, length );
-    return( kr );
-}
-
-IOReturn IOGeneralMemoryDescriptor::doUnmap(
+            // we have to make sure that these guys don't get copied if we fork.
+            err = vm_inherit( map, ref->mapped, ref->size, VM_INHERIT_NONE);
+            assert( KERN_SUCCESS == err );
+        }
+    }
+    while( false );
+
+    return( err );
+}
+
+kern_return_t 
+IOMemoryDescriptorMapMemEntry(vm_map_t map, ipc_port_t entry, IOOptionBits options, bool pageable,
+				mach_vm_size_t offset, 
+				mach_vm_address_t * address, mach_vm_size_t length)
+{
+    IOReturn err;
+    IOMemoryDescriptorMapAllocRef ref;
+
+    ref.sharedMem	= entry;
+    ref.sourceOffset   	= offset;
+    ref.options		= options;
+
+    ref.size = length;
+
+    if (options & kIOMapAnywhere)
+	// vm_map looks for addresses above here, even when VM_FLAGS_ANYWHERE
+	ref.mapped = 0;
+    else
+	ref.mapped = *address;
+
+    if( ref.sharedMem && (map == kernel_map) && pageable)
+	err = IOIteratePageableMaps( ref.size, &IOMemoryDescriptorMapAlloc, &ref );
+    else
+	err = IOMemoryDescriptorMapAlloc( map, &ref );
+
+    *address = ref.mapped;
+    return (err);
+}
+
+
+IOReturn IOMemoryDescriptor::doMap(
+	vm_map_t		__addressMap,
+	IOVirtualAddress *	__address,
+	IOOptionBits		options,
+	IOByteCount		__offset,
+	IOByteCount		__length )
+{
+    if (!(kIOMap64Bit & options)) panic("IOMemoryDescriptor::doMap !64bit");
+
+    _IOMemoryMap * mapping = (_IOMemoryMap *) *__address;
+    mach_vm_size_t offset  = mapping->fOffset + __offset;
+    mach_vm_size_t length  = mapping->fLength;
+
+    IOReturn	      err = kIOReturnSuccess;
+    memory_object_t   pager;
+    mach_vm_size_t    pageOffset;
+    IOPhysicalAddress sourceAddr;
+
+    do
+    {
+	sourceAddr = getSourceSegment( offset, NULL );
+	pageOffset = sourceAddr - trunc_page_32( sourceAddr );
+
+	if( reserved)
+	    pager = (memory_object_t) reserved->devicePager;
+	else
+	    pager = MACH_PORT_NULL;
+
+	if ((kIOMapReference|kIOMapUnique) == ((kIOMapReference|kIOMapUnique) & options))
+	{
+	    upl_t	   redirUPL2;
+	    vm_size_t      size;
+	    int		   flags;
+
+	    if (!_memEntry)
+	    {
+		err = kIOReturnNotReadable;
+		continue;
+	    }
+
+	    size = mapping->fLength + pageOffset;
+	    flags = UPL_COPYOUT_FROM | UPL_SET_INTERNAL 
+			| UPL_SET_LITE | UPL_SET_IO_WIRE | UPL_BLOCK_ACCESS;
+
+	    if (KERN_SUCCESS != memory_object_iopl_request((ipc_port_t) _memEntry, 0, &size, &redirUPL2,
+					    NULL, NULL,
+					    &flags))
+		redirUPL2 = NULL;
+
+	    err = upl_transpose(redirUPL2, mapping->fRedirUPL);
+	    if (kIOReturnSuccess != err)
+	    {
+		IOLog("upl_transpose(%x)\n", err);
+		err = kIOReturnSuccess;
+	    }
+
+	    if (redirUPL2)
+	    {
+		upl_commit(redirUPL2, NULL, 0);
+		upl_deallocate(redirUPL2);
+		redirUPL2 = 0;
+	    }
+	    {
+		// swap the memEntries since they now refer to different vm_objects
+		void * me = _memEntry;
+		_memEntry = mapping->fMemory->_memEntry;
+		mapping->fMemory->_memEntry = me;
+	    }
+	    if (pager)
+		err = handleFault( reserved->devicePager, mapping->fAddressMap, mapping->fAddress, offset, length, options );
+	}
+	else
+	{
+	    mach_vm_address_t address;
+
+	    if (!(options & kIOMapAnywhere))
+	    {
+		address = trunc_page_64(mapping->fAddress);
+		if( (mapping->fAddress - address) != pageOffset)
+		{
+		    err = kIOReturnVMError;
+		    continue;
+		}
+	    }
+
+	    err = IOMemoryDescriptorMapMemEntry(mapping->fAddressMap, (ipc_port_t) _memEntry,
+						    options, (kIOMemoryBufferPageable & _flags),
+						    offset, &address, round_page_64(length + pageOffset));
+	    if( err != KERN_SUCCESS)
+		continue;
+
+	    if (!_memEntry || pager)
+	    {
+		err = handleFault( pager, mapping->fAddressMap, address, offset, length, options );
+		if (err != KERN_SUCCESS)
+		    doUnmap( mapping->fAddressMap, (IOVirtualAddress) mapping, 0 );
+	    }
+
+#ifdef DEBUG
+	if (kIOLogMapping & gIOKitDebug)
+	    IOLog("mapping(%x) desc %p @ %lx, map %p, address %qx, offset %qx, length %qx\n", 
+		    err, this, sourceAddr, mapping, address, offset, length);
+#endif
+
+	    if (err == KERN_SUCCESS)
+		mapping->fAddress = address + pageOffset;
+	    else
+		mapping->fAddress = NULL;
+	}
+    }
+    while( false );
+
+    return (err);
+}
+
+enum {
+    kIOMemoryRedirected	= 0x00010000
+};
+
+IOReturn IOMemoryDescriptor::handleFault(
+        void *			_pager,
 	vm_map_t		addressMap,
-	IOVirtualAddress	logical,
-	IOByteCount		length )
-{
-    // could be much better
-    if( _task && (addressMap == getMapForTask(_task, _ranges.v[0].address)) && (1 == _rangesCount)
-	 && (logical == _ranges.v[0].address)
-	 && (length <= _ranges.v[0].length) )
-	    return( kIOReturnSuccess );
-
-    return( super::doUnmap( addressMap, logical, length ));
-}
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-extern "C" {
-// osfmk/device/iokit_rpc.c
-extern kern_return_t IOMapPages( vm_map_t map, vm_offset_t va, vm_offset_t pa,
-                                 vm_size_t length, unsigned int mapFlags);
-extern kern_return_t IOUnmapPages(vm_map_t map, vm_offset_t va, vm_size_t length);
-};
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-static IORecursiveLock * gIOMemoryLock;
-
-#define LOCK	IORecursiveLockLock( gIOMemoryLock)
-#define UNLOCK	IORecursiveLockUnlock( gIOMemoryLock)
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-OSDefineMetaClass( IOMemoryMap, OSObject )
-OSDefineAbstractStructors( IOMemoryMap, OSObject )
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-class _IOMemoryMap : public IOMemoryMap
-{
-    OSDeclareDefaultStructors(_IOMemoryMap)
-
-    IOMemoryDescriptor * memory;
-    IOMemoryMap *	superMap;
-    IOByteCount		offset;
-    IOByteCount		length;
-    IOVirtualAddress	logical;
-    task_t		addressTask;
-    vm_map_t		addressMap;
-    IOOptionBits	options;
-
-public:
-    virtual void free();
-
-    // IOMemoryMap methods
-    virtual IOVirtualAddress 	getVirtualAddress();
-    virtual IOByteCount 	getLength();
-    virtual task_t		getAddressTask();
-    virtual IOMemoryDescriptor * getMemoryDescriptor();
-    virtual IOOptionBits 	getMapOptions();
-
-    virtual IOReturn 		unmap();
-    virtual void 		taskDied();
-
-    virtual IOPhysicalAddress 	getPhysicalSegment(IOByteCount offset,
-	       					   IOByteCount * length);
-
-    // for IOMemoryDescriptor use
-    _IOMemoryMap * isCompatible(
-		IOMemoryDescriptor *	owner,
-                task_t			intoTask,
-                IOVirtualAddress	toAddress,
-                IOOptionBits		options,
-                IOByteCount		offset,
-                IOByteCount		length );
-
-    bool init(
-	IOMemoryDescriptor *	memory,
-	IOMemoryMap *		superMap,
-        IOByteCount		offset,
-        IOByteCount		length );
-
-    bool init(
-	IOMemoryDescriptor *	memory,
-	task_t			intoTask,
-	IOVirtualAddress	toAddress,
-	IOOptionBits		options,
-        IOByteCount		offset,
-        IOByteCount		length );
-
-    IOReturn redirect(
-	task_t			intoTask, bool redirect );
-};
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-#undef super
-#define super IOMemoryMap
-
-OSDefineMetaClassAndStructors(_IOMemoryMap, IOMemoryMap)
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-bool _IOMemoryMap::init(
-	IOMemoryDescriptor *	_memory,
-	IOMemoryMap *		_superMap,
-        IOByteCount		_offset,
-        IOByteCount		_length )
-{
-
-    if( !super::init())
-	return( false);
-
-    if( (_offset + _length) > _superMap->getLength())
-	return( false);
-
-    _memory->retain();
-    memory	= _memory;
-    _superMap->retain();
-    superMap 	= _superMap;
-
-    offset	= _offset;
-    if( _length)
-        length	= _length;
-    else
-        length	= _memory->getLength();
-
-    options	= superMap->getMapOptions();
-    logical	= superMap->getVirtualAddress() + offset;
-
-    return( true );
-}
-
-bool _IOMemoryMap::init(
-        IOMemoryDescriptor *	_memory,
-        task_t			intoTask,
-        IOVirtualAddress	toAddress,
-        IOOptionBits		_options,
-        IOByteCount		_offset,
-        IOByteCount		_length )
-{
-    bool	ok;
-
-    if( (!_memory) || (!intoTask) || !super::init())
-	return( false);
-
-    if( (_offset + _length) > _memory->getLength())
-	return( false);
-
-    addressMap  = get_task_map(intoTask);
+	mach_vm_address_t	address,
+	mach_vm_size_t		sourceOffset,
+	mach_vm_size_t		length,
+        IOOptionBits		options )
+{
+    IOReturn		err = kIOReturnSuccess;
+    memory_object_t	pager = (memory_object_t) _pager;
+    mach_vm_size_t	size;
+    mach_vm_size_t	bytes;
+    mach_vm_size_t	page;
+    mach_vm_size_t	pageOffset;
+    mach_vm_size_t	pagerOffset;
+    IOPhysicalLength	segLen;
+    addr64_t		physAddr;
+
     if( !addressMap)
-	return( false);
-    kernel_vm_map_reference(addressMap);
-
-    _memory->retain();
-    memory	= _memory;
-
-    offset	= _offset;
-    if( _length)
-        length	= _length;
-    else
-        length	= _memory->getLength();
-
-    addressTask	= intoTask;
-    logical	= toAddress;
-    options 	= _options;
-
-    if( options & kIOMapStatic)
-	ok = true;
-    else
-	ok = (kIOReturnSuccess == memory->doMap( addressMap, &logical,
-						 options, offset, length ));
-    if( !ok) {
-	logical = 0;
-        memory->release();
-        memory = 0;
-        vm_map_deallocate(addressMap);
-        addressMap = 0;
-    }
-    return( ok );
-}
-
-IOReturn IOMemoryDescriptor::doMap(
-	vm_map_t		addressMap,
-	IOVirtualAddress *	atAddress,
-	IOOptionBits		options,
-	IOByteCount		sourceOffset = 0,
-	IOByteCount		length = 0 )
-{
-    IOReturn		err = kIOReturnSuccess;
-    vm_size_t		ourSize;
-    vm_size_t		bytes;
-    vm_offset_t		mapped;
-    vm_address_t	logical;
-    IOByteCount		pageOffset;
-    IOPhysicalLength	segLen;
-    IOPhysicalAddress	physAddr;
-
-    if( 0 == length)
-	length = getLength();
-
-    physAddr = getPhysicalSegment( sourceOffset, &segLen );
+    {
+        if( kIOMemoryRedirected & _flags)
+	{
+#ifdef DEBUG
+            IOLog("sleep mem redirect %p, %qx\n", this, sourceOffset);
+#endif
+            do {
+	    	SLEEP;
+            } while( kIOMemoryRedirected & _flags );
+        }
+
+        return( kIOReturnSuccess );
+    }
+
+    physAddr = getPhysicalSegment64( sourceOffset, &segLen );
     assert( physAddr );
-
-    pageOffset = physAddr - trunc_page( physAddr );
-    ourSize = length + pageOffset;
+    pageOffset = physAddr - trunc_page_64( physAddr );
+    pagerOffset = sourceOffset;
+
+    size = length + pageOffset;
     physAddr -= pageOffset;
 
-    logical = *atAddress;
-    if( 0 == (options & kIOMapAnywhere)) {
-        mapped = trunc_page( logical );
-	if( (logical - mapped) != pageOffset)
-	    err = kIOReturnVMError;
-    }
-    if( kIOReturnSuccess == err)
-        err = vm_allocate( addressMap, &mapped, ourSize,
-			   ((options & kIOMapAnywhere) ? VM_FLAGS_ANYWHERE : VM_FLAGS_FIXED)
-                           | VM_MAKE_TAG(VM_MEMORY_IOKIT) );
-
-    if( err) {
-#ifdef DEBUG
-        kprintf("IOMemoryDescriptor::doMap: vm_allocate() "
-		"returned %08x\n", err);
-#endif
-        return( err);
-    }
-
-    // we have to make sure that these guys don't get copied if we fork.
-    err = vm_inherit( addressMap, mapped, ourSize, VM_INHERIT_NONE);
-    if( err != KERN_SUCCESS) {
-        doUnmap( addressMap, mapped, ourSize);	// back out
-        return( err);
-    }
-
-    logical = mapped;
-    *atAddress = mapped + pageOffset;
-
     segLen += pageOffset;
-    bytes = ourSize;
-    do {
+    bytes = size;
+    do
+    {
 	// in the middle of the loop only map whole pages
 	if( segLen >= bytes)
 	    segLen = bytes;
-	else if( segLen != trunc_page( segLen))
+	else if( segLen != trunc_page_32( segLen))
 	    err = kIOReturnVMError;
-        if( physAddr != trunc_page( physAddr))
+        if( physAddr != trunc_page_64( physAddr))
 	    err = kIOReturnBadArgument;
+	if (kIOReturnSuccess != err)
+	    break;
 
 #ifdef DEBUG
 	if( kIOLogMapping & gIOKitDebug)
-	    kprintf("_IOMemoryMap::map(%x) %08x->%08x:%08x\n",
-                addressMap, mapped + pageOffset, physAddr + pageOffset,
+	    IOLog("_IOMemoryMap::map(%p) 0x%qx->0x%qx:0x%qx\n",
+                addressMap, address + pageOffset, physAddr + pageOffset,
 		segLen - pageOffset);
 #endif
 
-	if( kIOReturnSuccess == err)
-            err = IOMapPages( addressMap, mapped, physAddr, segLen, options );
-	if( err)
-	    break;
+
+        if( pager) {
+            if( reserved && reserved->pagerContig) {
+                IOPhysicalLength	allLen;
+                addr64_t		allPhys;
+
+                allPhys = getPhysicalSegment64( 0, &allLen );
+                assert( allPhys );
+		err = device_pager_populate_object( pager, 0, atop_64(allPhys), round_page_32(allLen) );
+            }
+	    else
+	    {
+
+		for( page = 0;
+                     (page < segLen) && (KERN_SUCCESS == err);
+                     page += page_size)
+		{
+		    err = device_pager_populate_object(pager, pagerOffset,
+			    (ppnum_t)(atop_64(physAddr + page)), page_size);
+		    pagerOffset += page_size;
+                }
+            }
+            assert( KERN_SUCCESS == err );
+            if( err)
+                break;
+        }
+
+	// This call to vm_fault causes an early pmap level resolution
+	// of the mappings created above for kernel mappings, since
+	// faulting in later can't take place from interrupt level.
+	/*  *** ALERT *** */
+	/*  *** Temporary Workaround *** */
+
+	if ((addressMap == kernel_map) && !(kIOMemoryRedirected & _flags))
+	{
+		vm_fault(addressMap, 
+			 (vm_map_offset_t)address, 
+			 VM_PROT_READ|VM_PROT_WRITE, 
+			 FALSE, THREAD_UNINT, NULL, 
+			 (vm_map_offset_t)0);
+	}
+
+	/*  *** Temporary Workaround *** */
+	/*  *** ALERT *** */
 
 	sourceOffset += segLen - pageOffset;
-	mapped += segLen;
+	address += segLen;
 	bytes -= segLen;
 	pageOffset = 0;
 
-    } while( bytes
-	&& (physAddr = getPhysicalSegment( sourceOffset, &segLen )));
-
-    if( bytes)
+    } 
+    while (bytes && (physAddr = getPhysicalSegment64( sourceOffset, &segLen )));
+
+    if (bytes)
         err = kIOReturnBadArgument;
-    if( err)
-	doUnmap( addressMap, logical, ourSize );
-    else
-        mapped = true;
-
-    return( err );
+
+    return (err);
 }
 
 IOReturn IOMemoryDescriptor::doUnmap(
 	vm_map_t		addressMap,
-	IOVirtualAddress	logical,
-	IOByteCount		length )
-{
-    IOReturn	err;
+	IOVirtualAddress	__address,
+	IOByteCount		__length )
+{
+    IOReturn	      err;
+    mach_vm_address_t address;
+    mach_vm_size_t    length;
+
+    if (__length)
+    {
+	address = __address;
+	length  = __length;
+    }
+    else
+    {
+	addressMap = ((_IOMemoryMap *) __address)->fAddressMap;
+	address    = ((_IOMemoryMap *) __address)->fAddress;
+	length     = ((_IOMemoryMap *) __address)->fLength;
+    }
+
+    if( _memEntry && (addressMap == kernel_map) && (kIOMemoryBufferPageable & _flags))
+	addressMap = IOPageableMapForAddress( address );
 
 #ifdef DEBUG
     if( kIOLogMapping & gIOKitDebug)
-	kprintf("IOMemoryDescriptor::doUnmap(%x) %08x:%08x\n",
-                addressMap, logical, length );
+	IOLog("IOMemoryDescriptor::doUnmap map %p, 0x%qx:0x%qx\n",
+		addressMap, address, length );
 #endif
 
-    if( (addressMap == kernel_map) || (addressMap == get_task_map(current_task())))
-        err = vm_deallocate( addressMap, logical, length );
-    else
-        err = kIOReturnSuccess;
-
-    return( err );
-}
-
-IOReturn IOMemoryDescriptor::redirect( task_t safeTask, bool redirect )
-{
-    IOReturn		err;
+    err = mach_vm_deallocate( addressMap, address, length );
+
+    return (err);
+}
+
+IOReturn IOMemoryDescriptor::redirect( task_t safeTask, bool doRedirect )
+{
+    IOReturn		err = kIOReturnSuccess;
     _IOMemoryMap *	mapping = 0;
     OSIterator *	iter;
 
     LOCK;
 
+    if( doRedirect)
+        _flags |= kIOMemoryRedirected;
+    else
+        _flags &= ~kIOMemoryRedirected;
+
     do {
 	if( (iter = OSCollectionIterator::withCollection( _mappings))) {
-            while( (mapping = (_IOMemoryMap *) iter->getNextObject()))
-                mapping->redirect( safeTask, redirect );
-
-            iter->release();
-        }
+	    while( (mapping = (_IOMemoryMap *) iter->getNextObject()))
+		mapping->redirect( safeTask, doRedirect );
+
+	    iter->release();
+	}
     } while( false );
+
+    if (!doRedirect)
+    {
+        WAKEUP;
+    }
 
     UNLOCK;
 
     // temporary binary compatibility
     IOSubMemoryDescriptor * subMem;
     if( (subMem = OSDynamicCast( IOSubMemoryDescriptor, this)))
-        err = subMem->redirect( safeTask, redirect );
+	err = subMem->redirect( safeTask, doRedirect );
     else
-        err = kIOReturnSuccess;
+	err = kIOReturnSuccess;
 
     return( err );
 }
 
-IOReturn IOSubMemoryDescriptor::redirect( task_t safeTask, bool redirect )
-{
-// temporary binary compatibility   IOMemoryDescriptor::redirect( safeTask, redirect );
-    return( _parent->redirect( safeTask, redirect ));
-}
-
-IOReturn _IOMemoryMap::redirect( task_t safeTask, bool redirect )
+IOReturn IOSubMemoryDescriptor::redirect( task_t safeTask, bool doRedirect )
+{
+    return( _parent->redirect( safeTask, doRedirect ));
+}
+
+IOReturn _IOMemoryMap::redirect( task_t safeTask, bool doRedirect )
 {
     IOReturn err = kIOReturnSuccess;
 
-    if( superMap) {
-//        err = ((_IOMemoryMap *)superMap)->redirect( safeTask, redirect );
+    if( fSuperMap) {
+//        err = ((_IOMemoryMap *)superMap)->redirect( safeTask, doRedirect );
     } else {
 
         LOCK;
-        if( logical && addressMap
-        && (get_task_map( safeTask) != addressMap)
-        && (0 == (options & kIOMapStatic))) {
-    
-            IOUnmapPages( addressMap, logical, length );
-            if( !redirect) {
-                err = vm_deallocate( addressMap, logical, length );
-                err = memory->doMap( addressMap, &logical,
-                                     (options & ~kIOMapAnywhere) /*| kIOMapReserve*/ );
-            } else
-                err = kIOReturnSuccess;
+
+	do
+	{
+	    if (!fAddress)
+		break;
+	    if (!fAddressMap)
+		break;
+
+	    if ((!safeTask || (get_task_map(safeTask) != fAddressMap))
+	      && (0 == (fOptions & kIOMapStatic)))
+	    {
+		IOUnmapPages( fAddressMap, fAddress, fLength );
+		if(!doRedirect && safeTask
+		 && (((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical) 
+		    || ((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64)))
+		 {
+		    IOVirtualAddress iova = (IOVirtualAddress) this;
+		    err = mach_vm_deallocate( fAddressMap, fAddress, fLength );
+		    err = fMemory->doMap( fAddressMap, &iova,
+					 (fOptions & ~kIOMapAnywhere) | kIOMap64Bit/*| kIOMapReserve*/,
+					 0, 0 );
+		} else
+		    err = kIOReturnSuccess;
 #ifdef DEBUG
-            IOLog("IOMemoryMap::redirect(%d, %x) %x from %lx\n", redirect, err, logical, addressMap);
+		IOLog("IOMemoryMap::redirect(%d, %p) 0x%qx:0x%qx from %p\n", doRedirect, this, fAddress, fLength, fAddressMap);
 #endif
-        }
-        UNLOCK;
-    }
+	    }
+	    else if (kIOMapWriteCombineCache == (fOptions & kIOMapCacheMask))
+	    {
+		IOOptionBits newMode;
+		newMode = (fOptions & ~kIOMapCacheMask) | (doRedirect ? kIOMapInhibitCache : kIOMapWriteCombineCache);
+		IOProtectCacheMode(fAddressMap, fAddress, fLength, newMode);
+	    }
+	}
+	while (false);
+	UNLOCK;
+    }
+
+    if ((((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
+	 || ((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64))
+     && safeTask
+     && (doRedirect != (0 != (fMemory->_flags & kIOMemoryRedirected))))
+	fMemory->redirect(safeTask, doRedirect);
 
     return( err );
 }
@@ -1404,17 +2830,21 @@
 
     LOCK;
 
-    if( logical && addressMap && (0 == superMap)
-	&& (0 == (options & kIOMapStatic))) {
-
-        err = memory->doUnmap( addressMap, logical, length );
-        vm_map_deallocate(addressMap);
-        addressMap = 0;
+    if( fAddress && fAddressMap && (0 == fSuperMap) && fMemory
+	&& (0 == (fOptions & kIOMapStatic))) {
+
+        err = fMemory->doUnmap(fAddressMap, (IOVirtualAddress) this, 0);
 
     } else
 	err = kIOReturnSuccess;
 
-    logical = 0;
+    if (fAddressMap)
+    {
+        vm_map_deallocate(fAddressMap);
+        fAddressMap = 0;
+    }
+
+    fAddress = 0;
 
     UNLOCK;
 
@@ -1424,109 +2854,153 @@
 void _IOMemoryMap::taskDied( void )
 {
     LOCK;
-    if( addressMap) {
-        vm_map_deallocate(addressMap);
-        addressMap = 0;
-    }
-    addressTask	= 0;
-    logical	= 0;
+    if( fAddressMap) {
+        vm_map_deallocate(fAddressMap);
+        fAddressMap = 0;
+    }
+    fAddressTask = 0;
+    fAddress	 = 0;
     UNLOCK;
 }
 
+// Overload the release mechanism.  All mappings must be a member
+// of a memory descriptors _mappings set.  This means that we
+// always have 2 references on a mapping.  When either of these mappings
+// are released we need to free ourselves.
+void _IOMemoryMap::taggedRelease(const void *tag) const
+{
+    LOCK;
+    super::taggedRelease(tag, 2);
+    UNLOCK;
+}
+
 void _IOMemoryMap::free()
 {
     unmap();
 
-    if( memory) {
+    if (fMemory)
+    {
         LOCK;
-	memory->removeMapping( this);
+	fMemory->removeMapping(this);
 	UNLOCK;
-	memory->release();
-    }
-
-    if( superMap)
-	superMap->release();
+	fMemory->release();
+    }
+
+    if (fOwner && (fOwner != fMemory))
+    {
+        LOCK;
+	fOwner->removeMapping(this);
+	UNLOCK;
+    }
+
+    if (fSuperMap)
+	fSuperMap->release();
+
+    if (fRedirUPL) {
+	upl_commit(fRedirUPL, NULL, 0);
+	upl_deallocate(fRedirUPL);
+    }
 
     super::free();
 }
 
 IOByteCount _IOMemoryMap::getLength()
 {
-    return( length );
+    return( fLength );
 }
 
 IOVirtualAddress _IOMemoryMap::getVirtualAddress()
 {
-    return( logical);
-}
+    if (fSuperMap)
+	fSuperMap->getVirtualAddress();
+    else if (fAddressMap && vm_map_is_64bit(fAddressMap))
+    {
+	OSReportWithBacktrace("IOMemoryMap::getVirtualAddress(0x%qx) called on 64b map; use ::getAddress()", fAddress);
+    }
+
+    return (fAddress);
+}
+
+mach_vm_address_t 	_IOMemoryMap::getAddress()
+{
+    return( fAddress);
+}
+
+mach_vm_size_t 	_IOMemoryMap::getSize()
+{
+    return( fLength );
+}
+
 
 task_t _IOMemoryMap::getAddressTask()
 {
-    if( superMap)
-	return( superMap->getAddressTask());
+    if( fSuperMap)
+	return( fSuperMap->getAddressTask());
     else
-        return( addressTask);
+        return( fAddressTask);
 }
 
 IOOptionBits _IOMemoryMap::getMapOptions()
 {
-    return( options);
+    return( fOptions);
 }
 
 IOMemoryDescriptor * _IOMemoryMap::getMemoryDescriptor()
 {
-    return( memory );
-}
-
-_IOMemoryMap * _IOMemoryMap::isCompatible(
-		IOMemoryDescriptor *	owner,
-                task_t			task,
-                IOVirtualAddress	toAddress,
-                IOOptionBits		_options,
-                IOByteCount		_offset,
-                IOByteCount		_length )
-{
-    _IOMemoryMap * mapping;
-
-    if( (!task) || (task != getAddressTask()))
+    return( fMemory );
+}
+
+_IOMemoryMap * _IOMemoryMap::copyCompatible(
+		_IOMemoryMap * newMapping )
+{
+    task_t		task      = newMapping->getAddressTask();
+    mach_vm_address_t	toAddress = newMapping->fAddress;
+    IOOptionBits	_options  = newMapping->fOptions;
+    mach_vm_size_t	_offset   = newMapping->fOffset;
+    mach_vm_size_t	_length   = newMapping->fLength;
+
+    if( (!task) || (!fAddressMap) || (fAddressMap != get_task_map(task)))
 	return( 0 );
-    if( (options ^ _options) & (kIOMapCacheMask | kIOMapReadOnly))
+    if( (fOptions ^ _options) & kIOMapReadOnly)
 	return( 0 );
-
-    if( (0 == (_options & kIOMapAnywhere)) && (logical != toAddress))
+    if( (kIOMapDefaultCache != (_options & kIOMapCacheMask)) 
+     && ((fOptions ^ _options) & kIOMapCacheMask))
 	return( 0 );
 
-    if( _offset < offset)
+    if( (0 == (_options & kIOMapAnywhere)) && (fAddress != toAddress))
 	return( 0 );
 
-    _offset -= offset;
-
-    if( (_offset + _length) > length)
+    if( _offset < fOffset)
 	return( 0 );
 
-    if( (length == _length) && (!_offset)) {
-        retain();
-	mapping = this;
-
-    } else {
-        mapping = new _IOMemoryMap;
-        if( mapping
-        && !mapping->init( owner, this, _offset, _length )) {
-            mapping->release();
-            mapping = 0;
-        }
-    }
-
-    return( mapping );
-}
-
-IOPhysicalAddress _IOMemoryMap::getPhysicalSegment( IOByteCount _offset,
-	       					    IOPhysicalLength * length)
+    _offset -= fOffset;
+
+    if( (_offset + _length) > fLength)
+	return( 0 );
+
+    retain();
+    if( (fLength == _length) && (!_offset))
+    {
+	newMapping->release();
+	newMapping = this;
+    }
+    else
+    {
+	newMapping->fSuperMap = this;
+	newMapping->fOffset   = _offset;
+	newMapping->fAddress  = fAddress + _offset;
+    }
+
+    return( newMapping );
+}
+
+IOPhysicalAddress 
+_IOMemoryMap::getPhysicalSegment( IOByteCount _offset, IOPhysicalLength * _length)
 {
     IOPhysicalAddress	address;
 
     LOCK;
-    address = memory->getPhysicalSegment( offset + _offset, length );
+    address = fMemory->getPhysicalSegment( fOffset + _offset, _length );
     UNLOCK;
 
     return( address );
@@ -1543,6 +3017,23 @@
 {
     if( 0 == gIOMemoryLock)
 	gIOMemoryLock = IORecursiveLockAlloc();
+
+    IORegistryEntry::getRegistryRoot()->setProperty(kIOMaximumMappedIOByteCountKey,
+						    ptoa_64(gIOMaximumMappedIOPageCount), 64);
+    if (!gIOCopyMapper)
+    {
+    	IOMapper *
+	mapper = new IOCopyMapper;
+	if (mapper)
+	{
+	    if (mapper->init() && mapper->start(NULL))
+		gIOCopyMapper = (IOCopyMapper *) mapper;
+	    else
+		mapper->release();
+	}
+    }
+
+    gIOLastPage = IOGetLastPageNumber();
 }
 
 void IOMemoryDescriptor::free( void )
@@ -1556,124 +3047,267 @@
 IOMemoryMap * IOMemoryDescriptor::setMapping(
 	task_t			intoTask,
 	IOVirtualAddress	mapAddress,
-	IOOptionBits		options = 0 )
-{
-    _IOMemoryMap *		map;
-
-    map = new _IOMemoryMap;
-
-    LOCK;
-
-    if( map
-     && !map->init( this, intoTask, mapAddress,
-                    options | kIOMapStatic, 0, getLength() )) {
-	map->release();
-	map = 0;
-    }
-
-    addMapping( map);
-
-    UNLOCK;
-
-    return( map);
+	IOOptionBits		options )
+{
+    return (createMappingInTask( intoTask, mapAddress,
+				    options | kIOMapStatic,
+				    0, getLength() ));
 }
 
 IOMemoryMap * IOMemoryDescriptor::map( 
-	IOOptionBits		options = 0 )
-{
-
-    return( makeMapping( this, kernel_task, 0,
-			options | kIOMapAnywhere,
-			0, getLength() ));
-}
-
-IOMemoryMap * IOMemoryDescriptor::map(
-	task_t			intoTask,
-	IOVirtualAddress	toAddress,
-	IOOptionBits		options,
-	IOByteCount		offset = 0,
-	IOByteCount		length = 0 )
-{
-    if( 0 == length)
-	length = getLength();
-
-    return( makeMapping( this, intoTask, toAddress, options, offset, length ));
-}
-
-IOMemoryMap * IOMemoryDescriptor::makeMapping(
-	IOMemoryDescriptor *	owner,
-	task_t			intoTask,
-	IOVirtualAddress	toAddress,
+	IOOptionBits		options )
+{
+    return (createMappingInTask( kernel_task, 0,
+				options | kIOMapAnywhere,
+				0, getLength() ));
+}
+
+IOMemoryMap * IOMemoryDescriptor::map( 
+	task_t		        intoTask,
+	IOVirtualAddress	atAddress,
 	IOOptionBits		options,
 	IOByteCount		offset,
 	IOByteCount		length )
 {
-    _IOMemoryMap *	mapping = 0;
-    OSIterator *	iter;
+    if ((!(kIOMapAnywhere & options)) && vm_map_is_64bit(get_task_map(intoTask)))
+    {
+	OSReportWithBacktrace("IOMemoryDescriptor::map() in 64b task, use ::createMappingInTask()");
+	return (0);
+    }
+
+    return (createMappingInTask(intoTask, atAddress,
+				options, offset, length));
+}
+
+IOMemoryMap * IOMemoryDescriptor::createMappingInTask(
+	task_t			intoTask,
+	mach_vm_address_t	atAddress,
+	IOOptionBits		options,
+	mach_vm_size_t		offset,
+	mach_vm_size_t		length)
+{
+    IOMemoryMap  * result;
+    _IOMemoryMap * mapping;
+
+    if (0 == length)
+	length = getLength();
+
+    mapping = new _IOMemoryMap;
+
+    if( mapping
+     && !mapping->init( intoTask, atAddress,
+			options, offset, length )) {
+	mapping->release();
+	mapping = 0;
+    }
+
+    if (mapping)
+	result = makeMapping(this, intoTask, (IOVirtualAddress) mapping, options | kIOMap64Bit, 0, 0);
+    else
+	result = 0;
+
+#ifdef DEBUG
+    if (!result)
+	IOLog("createMappingInTask failed desc %p, addr %qx, options %lx, offset %qx, length %qx\n",
+		    this, atAddress, options, offset, length);
+#endif
+
+    return (result);
+}
+
+IOReturn _IOMemoryMap::redirect(IOMemoryDescriptor * newBackingMemory,
+			        IOOptionBits         options,
+			        IOByteCount          offset)
+{
+    return (redirect(newBackingMemory, options, (mach_vm_size_t)offset));
+}
+
+IOReturn _IOMemoryMap::redirect(IOMemoryDescriptor * newBackingMemory,
+			        IOOptionBits         options,
+			        mach_vm_size_t       offset)
+{
+    IOReturn err = kIOReturnSuccess;
+    IOMemoryDescriptor * physMem = 0;
 
     LOCK;
 
-    do {
-	// look for an existing mapping
-	if( (iter = OSCollectionIterator::withCollection( _mappings))) {
-
-            while( (mapping = (_IOMemoryMap *) iter->getNextObject())) {
-
-		if( (mapping = mapping->isCompatible( 
-					owner, intoTask, toAddress,
-					options | kIOMapReference,
-					offset, length )))
-		    break;
-            }
-            iter->release();
-            if( mapping)
-                continue;
-        }
-
-
-	if( mapping || (options & kIOMapReference))
+    if (fAddress && fAddressMap) do 
+    {
+	if (((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
+	    || ((fMemory->_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64))
+	{
+	    physMem = fMemory;
+	    physMem->retain();
+	}
+
+	if (!fRedirUPL)
+	{
+	    vm_size_t size = fLength;
+	    int flags = UPL_COPYOUT_FROM | UPL_SET_INTERNAL 
+			| UPL_SET_LITE | UPL_SET_IO_WIRE | UPL_BLOCK_ACCESS;
+	    if (KERN_SUCCESS != memory_object_iopl_request((ipc_port_t) fMemory->_memEntry, 0, &size, &fRedirUPL,
+					    NULL, NULL,
+					    &flags))
+		fRedirUPL = 0;
+
+	    if (physMem)
+	    {
+		IOUnmapPages( fAddressMap, fAddress, fLength );
+		physMem->redirect(0, true);
+	    }
+	}
+
+	if (newBackingMemory)
+	{
+	    if (newBackingMemory != fMemory)
+	    {
+		fOffset = 0;
+		if (this != newBackingMemory->makeMapping(newBackingMemory, fAddressTask, (IOVirtualAddress) this, 
+							    options | kIOMapUnique | kIOMapReference | kIOMap64Bit,
+							    offset, fLength))
+		    err = kIOReturnError;
+	    }
+	    if (fRedirUPL)
+	    {
+		upl_commit(fRedirUPL, NULL, 0);
+		upl_deallocate(fRedirUPL);
+		fRedirUPL = 0;
+	    }
+	    if (physMem)
+		physMem->redirect(0, false);
+	}
+    }
+    while (false);
+
+    UNLOCK;
+
+    if (physMem)
+	physMem->release();
+
+    return (err);
+}
+
+IOMemoryMap * IOMemoryDescriptor::makeMapping(
+	IOMemoryDescriptor *	owner,
+	task_t			__intoTask,
+	IOVirtualAddress	__address,
+	IOOptionBits		options,
+	IOByteCount		__offset,
+	IOByteCount		__length )
+{
+    if (!(kIOMap64Bit & options)) panic("IOMemoryDescriptor::makeMapping !64bit");
+
+    IOMemoryDescriptor * mapDesc = 0;
+    _IOMemoryMap *	 result = 0;
+    OSIterator *	 iter;
+
+    _IOMemoryMap * mapping = (_IOMemoryMap *) __address;
+    mach_vm_size_t offset  = mapping->fOffset + __offset;
+    mach_vm_size_t length  = mapping->fLength;
+
+    mapping->fOffset = offset;
+
+    LOCK;
+
+    do
+    {
+	if (kIOMapStatic & options)
+	{
+	    result = mapping;
+	    addMapping(mapping);
+	    mapping->setMemoryDescriptor(this, 0);
 	    continue;
-
-	owner = this;
-
-        mapping = new _IOMemoryMap;
-	if( mapping
-	&& !mapping->init( owner, intoTask, toAddress, options,
-			   offset, length )) {
-
-	    IOLog("Didn't make map %08lx : %08lx\n", offset, length );
+	}
+
+	if (kIOMapUnique & options)
+	{
+	    IOPhysicalAddress phys;
+	    IOByteCount       physLen;
+
+//	    if (owner != this)		continue;
+
+	    if (((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical)
+		|| ((_flags & kIOMemoryTypeMask) == kIOMemoryTypePhysical64))
+	    {
+		phys = getPhysicalSegment(offset, &physLen);
+		if (!phys || (physLen < length))
+		    continue;
+    
+		mapDesc = IOMemoryDescriptor::withPhysicalAddress(
+				phys, length, _direction);
+		if (!mapDesc)
+		    continue;
+		offset = 0;
+		mapping->fOffset = offset;
+	    }
+	}
+	else
+	{
+	    // look for a compatible existing mapping
+	    if( (iter = OSCollectionIterator::withCollection(_mappings)))
+	    {
+		_IOMemoryMap * lookMapping;
+		while ((lookMapping = (_IOMemoryMap *) iter->getNextObject()))
+		{
+		    if ((result = lookMapping->copyCompatible(mapping)))
+		    {
+			addMapping(result);
+			result->setMemoryDescriptor(this, offset);
+			break;
+		    }
+		}
+		iter->release();
+	    }
+	    if (result || (options & kIOMapReference))
+		continue;
+	}
+
+	if (!mapDesc)
+	{
+	    mapDesc = this;
+	    mapDesc->retain();
+	}
+	IOReturn
+	kr = mapDesc->doMap( 0, (IOVirtualAddress *) &mapping, options, 0, 0 );
+	if (kIOReturnSuccess == kr)
+	{
+	    result = mapping;
+	    mapDesc->addMapping(result);
+	    result->setMemoryDescriptor(mapDesc, offset);
+	}
+	else
+	{
 	    mapping->release();
-            mapping = 0;
+	    mapping = NULL;
 	}
-
-    } while( false );
-
-    owner->addMapping( mapping);
+    }
+    while( false );
 
     UNLOCK;
 
-    return( mapping);
+    if (mapDesc)
+	mapDesc->release();
+
+    return (result);
 }
 
 void IOMemoryDescriptor::addMapping(
 	IOMemoryMap * mapping )
 {
-    if( mapping) {
+    if( mapping)
+    {
         if( 0 == _mappings)
             _mappings = OSSet::withCapacity(1);
-	if( _mappings && _mappings->setObject( mapping ))
-	    mapping->release(); 	/* really */
+	if( _mappings )
+	    _mappings->setObject( mapping );
     }
 }
 
 void IOMemoryDescriptor::removeMapping(
 	IOMemoryMap * mapping )
 {
-    if( _mappings) {
-        mapping->retain();
-        mapping->retain();
+    if( _mappings)
         _mappings->removeObject( mapping);
-    }
 }
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
@@ -1687,22 +3321,38 @@
 
 bool IOSubMemoryDescriptor::initSubRange( IOMemoryDescriptor * parent,
 					IOByteCount offset, IOByteCount length,
-					IODirection withDirection )
-{
-    if( !super::init())
-	return( false );
-
+					IODirection direction )
+{
     if( !parent)
 	return( false);
 
     if( (offset + length) > parent->getLength())
 	return( false);
+
+    /*
+     * We can check the _parent instance variable before having ever set it
+     * to an initial value because I/O Kit guarantees that all our instance
+     * variables are zeroed on an object's allocation.
+     */
+
+    if( !_parent) {
+	if( !super::init())
+	    return( false );
+    } else {
+	/*
+	 * An existing memory descriptor is being retargeted to
+	 * point to somewhere else.  Clean up our present state.
+	 */
+
+	_parent->release();
+	_parent = 0;
+    }
 
     parent->retain();
     _parent	= parent;
     _start	= offset;
     _length	= length;
-    _direction  = withDirection;
+    _direction  = direction;
     _tag	= parent->getTag();
 
     return( true );
@@ -1717,8 +3367,71 @@
 }
 
 
-IOPhysicalAddress IOSubMemoryDescriptor::getPhysicalSegment( IOByteCount offset,
-						      	IOByteCount * length )
+IOReturn
+IOSubMemoryDescriptor::dmaCommandOperation(DMACommandOps op, void *vData, UInt dataSize) const
+{
+    IOReturn rtn;
+
+    if (kIOMDGetCharacteristics == op) {
+
+	rtn = _parent->dmaCommandOperation(op, vData, dataSize);
+	if (kIOReturnSuccess == rtn) {
+	    IOMDDMACharacteristics *data = (IOMDDMACharacteristics *) vData;
+	    data->fLength = _length;
+	    data->fSGCount = 0;	// XXX gvdl: need to compute and pages
+	    data->fPages = 0;
+	    data->fPageAlign = 0;
+	}
+
+	return rtn;
+    }
+    else if (kIOMDWalkSegments & op) {
+	if (dataSize < sizeof(IOMDDMAWalkSegmentArgs))
+	    return kIOReturnUnderrun;
+
+	IOMDDMAWalkSegmentArgs *data =
+	    reinterpret_cast<IOMDDMAWalkSegmentArgs *>(vData);
+	UInt offset = data->fOffset;
+	UInt remain = _length - offset;
+	if ((int) remain <= 0)
+	    return (!remain)? kIOReturnOverrun : kIOReturnInternalError;
+
+	data->fOffset = offset + _start;
+	rtn = _parent->dmaCommandOperation(op, vData, dataSize);
+	if (data->fLength > remain)
+	    data->fLength = remain;
+	data->fOffset  = offset;
+
+	return rtn;
+    }
+    else
+	return kIOReturnBadArgument;
+}
+
+addr64_t
+IOSubMemoryDescriptor::getPhysicalSegment64(IOByteCount offset, IOByteCount * length)
+{
+    addr64_t	address;
+    IOByteCount	actualLength;
+
+    assert(offset <= _length);
+
+    if( length)
+        *length = 0;
+
+    if( offset >= _length)
+        return( 0 );
+
+    address = _parent->getPhysicalSegment64( offset + _start, &actualLength );
+
+    if( address && length)
+	*length = min( _length - offset, actualLength );
+
+    return( address );
+}
+
+IOPhysicalAddress
+IOSubMemoryDescriptor::getPhysicalSegment( IOByteCount offset, IOByteCount * length )
 {
     IOPhysicalAddress	address;
     IOByteCount		actualLength;
@@ -1739,14 +3452,47 @@
     return( address );
 }
 
+IOPhysicalAddress 
+IOSubMemoryDescriptor::getSourceSegment( IOByteCount offset, IOByteCount * length )
+{
+    IOPhysicalAddress	address;
+    IOByteCount		actualLength;
+
+    assert(offset <= _length);
+
+    if( length)
+        *length = 0;
+
+    if( offset >= _length)
+        return( 0 );
+
+    address = _parent->getSourceSegment( offset + _start, &actualLength );
+
+    if( address && length)
+	*length = min( _length - offset, actualLength );
+
+    return( address );
+}
+
 void * IOSubMemoryDescriptor::getVirtualSegment(IOByteCount offset,
 					IOByteCount * lengthOfSegment)
 {
     return( 0 );
 }
 
+IOReturn IOSubMemoryDescriptor::doMap(
+	vm_map_t		addressMap,
+	IOVirtualAddress *	atAddress,
+	IOOptionBits		options,
+	IOByteCount		sourceOffset,
+	IOByteCount		length )
+{
+    panic("IOSubMemoryDescriptor::doMap");
+    return (IOMemoryDescriptor::doMap(addressMap, atAddress, options, sourceOffset, length));
+}
+
 IOByteCount IOSubMemoryDescriptor::readBytes(IOByteCount offset,
-					void * bytes, IOByteCount withLength)
+					void * bytes, IOByteCount length)
 {
     IOByteCount	byteCount;
 
@@ -1757,14 +3503,14 @@
 
     LOCK;
     byteCount = _parent->readBytes( _start + offset, bytes,
-				min(withLength, _length - offset) );
+				min(length, _length - offset) );
     UNLOCK;
 
     return( byteCount );
 }
 
 IOByteCount IOSubMemoryDescriptor::writeBytes(IOByteCount offset,
-				const void* bytes, IOByteCount withLength)
+				const void* bytes, IOByteCount length)
 {
     IOByteCount	byteCount;
 
@@ -1775,14 +3521,44 @@
 
     LOCK;
     byteCount = _parent->writeBytes( _start + offset, bytes,
-				min(withLength, _length - offset) );
+				min(length, _length - offset) );
     UNLOCK;
 
     return( byteCount );
 }
 
+IOReturn IOSubMemoryDescriptor::setPurgeable( IOOptionBits newState,
+                                    IOOptionBits * oldState )
+{
+    IOReturn err;
+
+    LOCK;
+    err = _parent->setPurgeable( newState, oldState );
+    UNLOCK;
+
+    return( err );
+}
+
+IOReturn IOSubMemoryDescriptor::performOperation( IOOptionBits options,
+                                        IOByteCount offset, IOByteCount length )
+{
+    IOReturn err;
+
+    assert(offset <= _length);
+
+    if( offset >= _length)
+        return( kIOReturnOverrun );
+
+    LOCK;
+    err = _parent->performOperation( options, _start + offset,
+                                      min(length, _length - offset) );
+    UNLOCK;
+
+    return( err );
+}
+
 IOReturn IOSubMemoryDescriptor::prepare(
-		IODirection forDirection = kIODirectionNone)
+		IODirection forDirection)
 {
     IOReturn	err;
 
@@ -1794,7 +3570,7 @@
 }
 
 IOReturn IOSubMemoryDescriptor::complete(
-		IODirection forDirection = kIODirectionNone)
+		IODirection forDirection)
 {
     IOReturn	err;
 
@@ -1808,22 +3584,23 @@
 IOMemoryMap * IOSubMemoryDescriptor::makeMapping(
 	IOMemoryDescriptor *	owner,
 	task_t			intoTask,
-	IOVirtualAddress	toAddress,
+	IOVirtualAddress	address,
 	IOOptionBits		options,
 	IOByteCount		offset,
 	IOByteCount		length )
 {
-    IOMemoryMap * mapping;
-
-     mapping = (IOMemoryMap *) _parent->makeMapping(
-					_parent, intoTask,
-					toAddress - (_start + offset),
-					options | kIOMapReference,
-					_start + offset, length );
-
-    if( !mapping)
-	mapping = super::makeMapping( owner, intoTask, toAddress, options,
-					offset, length );
+    IOMemoryMap * mapping = 0;
+
+    if (!(kIOMap64Bit & options))
+    {
+	panic("IOSubMemoryDescriptor::makeMapping !64bit");
+    }
+
+    mapping = (IOMemoryMap *) _parent->makeMapping(
+					owner,
+					intoTask,
+					address,
+					options, _start + offset, length );
 
     return( mapping );
 }
@@ -1832,17 +3609,17 @@
 
 bool
 IOSubMemoryDescriptor::initWithAddress(void *      address,
-                                    IOByteCount   withLength,
-                                    IODirection withDirection)
+                                    IOByteCount   length,
+                                    IODirection direction)
 {
     return( false );
 }
 
 bool
 IOSubMemoryDescriptor::initWithAddress(vm_address_t address,
-                                    IOByteCount    withLength,
-                                    IODirection  withDirection,
-                                    task_t       withTask)
+                                    IOByteCount    length,
+                                    IODirection  direction,
+                                    task_t       task)
 {
     return( false );
 }
@@ -1850,8 +3627,8 @@
 bool
 IOSubMemoryDescriptor::initWithPhysicalAddress(
 				 IOPhysicalAddress	address,
-				 IOByteCount		withLength,
-				 IODirection      	withDirection )
+				 IOByteCount		length,
+				 IODirection      	direction )
 {
     return( false );
 }
@@ -1860,9 +3637,9 @@
 IOSubMemoryDescriptor::initWithRanges(
                                    	IOVirtualRange * ranges,
                                    	UInt32           withCount,
-                                   	IODirection      withDirection,
-                                   	task_t           withTask,
-                                  	bool             asReference = false)
+                                   	IODirection      direction,
+                                   	task_t           task,
+                                  	bool             asReference)
 {
     return( false );
 }
@@ -1870,20 +3647,165 @@
 bool
 IOSubMemoryDescriptor::initWithPhysicalRanges(	IOPhysicalRange * ranges,
                                         	UInt32           withCount,
-                                        	IODirection      withDirection,
-                                        	bool             asReference = false)
+                                        	IODirection      direction,
+                                        	bool             asReference)
 {
     return( false );
 }
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 0);
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 1);
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 2);
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 3);
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 4);
-OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 5);
+bool IOGeneralMemoryDescriptor::serialize(OSSerialize * s) const
+{
+    OSSymbol const *keys[2];
+    OSObject *values[2];
+    struct SerData {
+	user_addr_t address;
+	user_size_t length;
+    } *vcopy;
+    unsigned int index, nRanges;
+    bool result;
+
+    IOOptionBits type = _flags & kIOMemoryTypeMask;
+
+    if (s == NULL) return false;
+    if (s->previouslySerialized(this)) return true;
+
+    // Pretend we are an array.
+    if (!s->addXMLStartTag(this, "array")) return false;
+
+    nRanges = _rangesCount;
+    vcopy = (SerData *) IOMalloc(sizeof(SerData) * nRanges);
+    if (vcopy == 0) return false;
+
+    keys[0] = OSSymbol::withCString("address");
+    keys[1] = OSSymbol::withCString("length");
+
+    result = false;
+    values[0] = values[1] = 0;
+
+    // From this point on we can go to bail.
+
+    // Copy the volatile data so we don't have to allocate memory
+    // while the lock is held.
+    LOCK;
+    if (nRanges == _rangesCount) {
+	Ranges vec = _ranges;
+        for (index = 0; index < nRanges; index++) {
+	    user_addr_t addr; IOByteCount len;
+	    getAddrLenForInd(addr, len, type, vec, index);
+            vcopy[index].address = addr;
+            vcopy[index].length  = len;
+        }
+    } else {
+	// The descriptor changed out from under us.  Give up.
+        UNLOCK;
+	result = false;
+        goto bail;
+    }
+    UNLOCK;
+
+    for (index = 0; index < nRanges; index++)
+    {
+	user_addr_t addr = vcopy[index].address;
+	IOByteCount len = (IOByteCount) vcopy[index].length;
+	values[0] =
+	    OSNumber::withNumber(addr, (((UInt64) addr) >> 32)? 64 : 32);
+	if (values[0] == 0) {
+	  result = false;
+	  goto bail;
+	}
+	values[1] = OSNumber::withNumber(len, sizeof(len) * 8);
+	if (values[1] == 0) {
+	  result = false;
+	  goto bail;
+	}
+        OSDictionary *dict = OSDictionary::withObjects((const OSObject **)values, (const OSSymbol **)keys, 2);
+	if (dict == 0) {
+	  result = false;
+	  goto bail;
+	}
+	values[0]->release();
+	values[1]->release();
+	values[0] = values[1] = 0;
+
+	result = dict->serialize(s);
+	dict->release();
+	if (!result) {
+	  goto bail;
+	}
+    }
+    result = s->addXMLEndTag("array");
+
+ bail:
+    if (values[0])
+      values[0]->release();
+    if (values[1])
+      values[1]->release();
+    if (keys[0])
+      keys[0]->release();
+    if (keys[1])
+      keys[1]->release();
+    if (vcopy)
+        IOFree(vcopy, sizeof(SerData) * nRanges);
+    return result;
+}
+
+bool IOSubMemoryDescriptor::serialize(OSSerialize * s) const
+{
+    if (!s) {
+	return (false);
+    }
+    if (s->previouslySerialized(this)) return true;
+
+    // Pretend we are a dictionary.
+    // We must duplicate the functionality of OSDictionary here
+    // because otherwise object references will not work;
+    // they are based on the value of the object passed to
+    // previouslySerialized and addXMLStartTag.
+
+    if (!s->addXMLStartTag(this, "dict")) return false;
+
+    char const *keys[3] = {"offset", "length", "parent"};
+
+    OSObject *values[3];
+    values[0] = OSNumber::withNumber(_start, sizeof(_start) * 8);
+    if (values[0] == 0)
+	return false;
+    values[1] = OSNumber::withNumber(_length, sizeof(_length) * 8);
+    if (values[1] == 0) {
+	values[0]->release();
+	return false;
+    }
+    values[2] = _parent;
+
+    bool result = true;
+    for (int i=0; i<3; i++) {
+        if (!s->addString("<key>") ||
+	    !s->addString(keys[i]) ||
+	    !s->addXMLEndTag("key") ||
+	    !values[i]->serialize(s)) {
+	  result = false;
+	  break;
+        }
+    }
+    values[0]->release();
+    values[1]->release();
+    if (!result) {
+      return false;
+    }
+
+    return s->addXMLEndTag("dict");
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 0);
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 1);
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 2);
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 3);
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 4);
+OSMetaClassDefineReservedUsed(IOMemoryDescriptor, 5);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 6);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 7);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 8);
@@ -1894,3 +3816,11 @@
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 13);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 14);
 OSMetaClassDefineReservedUnused(IOMemoryDescriptor, 15);
+
+/* ex-inline function implementation */
+IOPhysicalAddress 
+IOMemoryDescriptor::getPhysicalAddress()
+        { return( getPhysicalSegment( 0, 0 )); }
+
+
+