This is xnu-8019. See this file in:
/*
 * Copyright (c) 1998-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * 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.
 *
 * 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <IOKit/IODeviceTreeSupport.h>
#include <libkern/c++/OSContainers.h>
#include <libkern/c++/OSSharedPtr.h>
#include <IOKit/IODeviceMemory.h>
#include <IOKit/IOService.h>
#include <IOKit/IOCatalogue.h>

#include <IOKit/IOLib.h>
#include <IOKit/IOKitKeys.h>

#include <pexpert/device_tree.h>

#if __arm64__
typedef UInt64  dtptr_t;
#else
typedef UInt32  dtptr_t;
#endif

#include <machine/machine_routines.h>

extern "C" {
int IODTGetLoaderInfo( const char *key, void **infoAddr, int *infosize );
void IODTFreeLoaderInfo( const char *key, void *infoAddr, int infoSize );
int IODTGetDefault(const char *key, void *infoAddr, unsigned int infoSize );
}

#include <IOKit/assert.h>

#define IODTSUPPORTDEBUG 0

struct IODTPersistent {
	IODTCompareAddressCellFunc  compareFunc;
};

struct IODTResolvers {
	unsigned int     alloc;
	unsigned int     count;
	IOLock         * lock;
	IODTPersistent * resolvers;
};

const IORegistryPlane * gIODTPlane;

static OSArray *    gIODTPHandles;
static OSArray *    gIODTPHandleMap;

static IODTResolvers *  gIODTResolvers;

const OSSymbol *        gIODTNameKey;
const OSSymbol *        gIODTUnitKey;
const OSSymbol *        gIODTCompatibleKey;
const OSSymbol *        gIODTTypeKey;
const OSSymbol *        gIODTModelKey;
const OSSymbol *        gIODTBridgeModelKey;
const OSSymbol *        gIODTTargetTypeKey;

const OSSymbol *        gIODTSizeCellKey;
const OSSymbol *        gIODTAddressCellKey;
const OSSymbol *        gIODTRangeKey;

const OSSymbol *        gIODTPersistKey;

const OSSymbol *        gIODTDefaultInterruptController;
const OSSymbol *        gIODTAAPLInterruptsKey;
const OSSymbol *        gIODTPHandleKey;
const OSSymbol *        gIODTInterruptCellKey;
const OSSymbol *        gIODTInterruptParentKey;
const OSSymbol *        gIODTNWInterruptMappingKey;

OSDictionary   *        gIODTSharedInterrupts;

static IORegistryEntry * MakeReferenceTable( DTEntry dtEntry, bool copy );
static void AddPHandle( IORegistryEntry * regEntry );
static void FreePhysicalMemory( vm_offset_t * range );
static bool IODTMapInterruptsSharing( IORegistryEntry * regEntry, OSDictionary * allInts );

// FIXME: Implementation of this function is hidden from the static analyzer.
// The analyzer doesn't know that the registry holds retains, and gets confused
// about releases after calls to 'attachToParent'.
// Feel free to remove the #ifndef and address the warning!
#ifndef __clang_analyzer__
IORegistryEntry *
IODeviceTreeAlloc( void * dtTop )
{
	IORegistryEntry *           parent;
	IORegistryEntry *           child;
	IORegistryIterator *        regIter;
	OpaqueDTEntryIterator       iter;
	DTEntry                     dtChild;
	DTEntry                     mapEntry;
	OSArray *                   stack;
	OSData *                    prop;
	OSDictionary *              allInts;
	vm_offset_t *               dtMap;
	unsigned int                propSize;
	bool                        intMap;
	bool                        foundDTNode;
	bool                        freeDT;

	gIODTPlane = IORegistryEntry::makePlane( kIODeviceTreePlane );

	gIODTNameKey                = OSSymbol::withCStringNoCopy( "name" );
	gIODTUnitKey                = OSSymbol::withCStringNoCopy( "AAPL,unit-string" );
	gIODTCompatibleKey  = OSSymbol::withCStringNoCopy( "compatible" );
	gIODTTypeKey                = OSSymbol::withCStringNoCopy( "device_type" );
	gIODTModelKey               = OSSymbol::withCStringNoCopy( "model" );
	gIODTBridgeModelKey         = OSSymbol::withCStringNoCopy( "bridge-model" );
	gIODTTargetTypeKey          = OSSymbol::withCStringNoCopy( "target-type" );
	gIODTSizeCellKey    = OSSymbol::withCStringNoCopy( "#size-cells" );
	gIODTAddressCellKey = OSSymbol::withCStringNoCopy( "#address-cells" );
	gIODTRangeKey               = OSSymbol::withCStringNoCopy( "ranges" );
	gIODTPersistKey             = OSSymbol::withCStringNoCopy( "IODTPersist" );

	assert(    gIODTPlane && gIODTCompatibleKey
	    && gIODTTypeKey && gIODTModelKey
	    && gIODTSizeCellKey && gIODTAddressCellKey && gIODTRangeKey
	    && gIODTPersistKey );

	gIODTDefaultInterruptController
	        = OSSymbol::withCStringNoCopy("IOPrimaryInterruptController");
	gIODTNWInterruptMappingKey
	        = OSSymbol::withCStringNoCopy("IONWInterrupts");

	gIODTAAPLInterruptsKey
	        = OSSymbol::withCStringNoCopy("AAPL,interrupts");
	gIODTPHandleKey
	        = OSSymbol::withCStringNoCopy("AAPL,phandle");

	gIODTInterruptParentKey
	        = OSSymbol::withCStringNoCopy("interrupt-parent");

	gIODTPHandles       = OSArray::withCapacity( 1 );
	gIODTPHandleMap     = OSArray::withCapacity( 1 );

	gIODTResolvers            = zalloc_permanent_type(IODTResolvers);
	gIODTResolvers->count     = 0;
	gIODTResolvers->alloc     = 2;
	gIODTResolvers->resolvers = IONewZero(IODTPersistent, gIODTResolvers->alloc);
	gIODTResolvers->lock      = IOLockAlloc();

	gIODTInterruptCellKey
	        = OSSymbol::withCStringNoCopy("#interrupt-cells");

	assert(    gIODTDefaultInterruptController && gIODTNWInterruptMappingKey
	    && gIODTAAPLInterruptsKey
	    && gIODTPHandleKey && gIODTInterruptParentKey
	    && gIODTPHandles && gIODTPHandleMap && gIODTInterruptCellKey
	    && gIODTResolvers && gIODTResolvers->lock && gIODTResolvers->resolvers
	    );

	foundDTNode = (kSuccess == SecureDTLookupEntry( NULL, "/chosen/memory-map", &mapEntry ))
	    && (kSuccess == SecureDTGetProperty( mapEntry,
	    "DeviceTree", (void const **) &dtMap, &propSize ))
	    && ((2 * sizeof(uint32_t)) == propSize);

	freeDT = foundDTNode && !SecureDTIsLockedDown();

	parent = MakeReferenceTable((DTEntry)dtTop, freeDT );

	stack = OSArray::withObjects((const OSObject **) &parent, 1, 10 );
	SecureDTInitEntryIterator((DTEntry)dtTop, &iter );

	do {
		parent = (IORegistryEntry *)stack->getObject( stack->getCount() - 1);
		//parent->release();
		stack->removeObject( stack->getCount() - 1);

		while (kSuccess == SecureDTIterateEntries( &iter, &dtChild)) {
			child = MakeReferenceTable( dtChild, freeDT );
			child->attachToParent( parent, gIODTPlane);

			AddPHandle( child );

			if (kSuccess == SecureDTEnterEntry( &iter, dtChild)) {
				stack->setObject( parent);
				parent = child;
			}
			// only registry holds retain
			child->release();
		}
	} while (stack->getCount()
	    && (kSuccess == SecureDTExitEntry( &iter, &dtChild)));

	stack->release();
	assert(kSuccess != SecureDTExitEntry(&iter, &dtChild));

	// parent is now root of the created tree

	// make root name first compatible entry (purely cosmetic)
	if ((prop = (OSData *) parent->getProperty( gIODTCompatibleKey))) {
		parent->setName( parent->getName(), gIODTPlane );
		parent->setName((const char *) prop->getBytesNoCopy());
	}

	// attach tree to meta root
	parent->attachToParent( IORegistryEntry::getRegistryRoot(), gIODTPlane);
	parent->release();

	if (freeDT) {
		// free original device tree
		SecureDTInit(NULL, 0);
		IODTFreeLoaderInfo( "DeviceTree",
		    (void *)dtMap[0], (int) round_page(dtMap[1]));
	}

	// adjust tree

	gIODTSharedInterrupts = OSDictionary::withCapacity(4);
	allInts = OSDictionary::withCapacity(4);
	intMap = false;
	regIter = IORegistryIterator::iterateOver( gIODTPlane,
	    kIORegistryIterateRecursively );
	assert( regIter && allInts && gIODTSharedInterrupts );
	if (regIter && allInts && gIODTSharedInterrupts) {
		while ((child = regIter->getNextObject())) {
			IODTMapInterruptsSharing( child, allInts );
			if (!intMap && child->getProperty( gIODTInterruptParentKey)) {
				intMap = true;
			}
			if (!strcmp("sep", child->getName())
			    || !strcmp("aop", child->getName())
			    || !strcmp("disp0", child->getName())) {
				uint32_t aotFlags = 1;
				child->setProperty("aot-power", &aotFlags, sizeof(aotFlags));
			}
		}
		regIter->release();
	}

#if IODTSUPPORTDEBUG
	parent->setProperty("allInts", allInts);
	parent->setProperty("sharedInts", gIODTSharedInterrupts);

	regIter = IORegistryIterator::iterateOver( gIODTPlane,
	    kIORegistryIterateRecursively );
	if (regIter) {
		while ((child = regIter->getNextObject())) {
			OSArray *
			    array = OSDynamicCast(OSArray, child->getProperty( gIOInterruptSpecifiersKey ));
			for (UInt32 i = 0; array && (i < array->getCount()); i++) {
				IOOptionBits options;
				IOReturn ret = IODTGetInterruptOptions( child, i, &options );
				if ((ret != kIOReturnSuccess) || options) {
					IOLog("%s[%ld] %ld (%x)\n", child->getName(), i, options, ret);
				}
			}
		}
		regIter->release();
	}
#endif

	allInts->release();

	if (intMap) {
		// set a key in the root to indicate we found NW interrupt mapping
		parent->setProperty( gIODTNWInterruptMappingKey,
		    (OSObject *) gIODTNWInterruptMappingKey );
	}

	return parent;
}
#endif

int
IODTGetLoaderInfo( const char *key, void **infoAddr, int *infoSize )
{
	IORegistryEntry             *chosen;
	OSData                              *propObj;
	dtptr_t                             *propPtr;
	unsigned int                propSize;
	int ret = -1;

	chosen = IORegistryEntry::fromPath( "/chosen/memory-map", gIODTPlane );
	if (chosen == NULL) {
		return -1;
	}

	propObj = OSDynamicCast( OSData, chosen->getProperty(key));
	if (propObj == NULL) {
		goto cleanup;
	}

	propSize = propObj->getLength();
	if (propSize != (2 * sizeof(dtptr_t))) {
		goto cleanup;
	}

	propPtr = (dtptr_t *)propObj->getBytesNoCopy();
	if (propPtr == NULL) {
		goto cleanup;
	}

	*infoAddr = (void *)(uintptr_t) (propPtr[0]);
	*infoSize = (int)               (propPtr[1]);

	ret = 0;

cleanup:
	chosen->release();

	return ret;
}

void
IODTFreeLoaderInfo( const char *key, void *infoAddr, int infoSize )
{
	vm_offset_t                 range[2];
	IORegistryEntry             *chosen;

	range[0] = (vm_offset_t)infoAddr;
	range[1] = (vm_offset_t)infoSize;
	FreePhysicalMemory( range );

	if (key != NULL) {
		chosen = IORegistryEntry::fromPath( "/chosen/memory-map", gIODTPlane );
		if (chosen != NULL) {
			chosen->removeProperty(key);
			chosen->release();
		}
	}
}

int
IODTGetDefault(const char *key, void *infoAddr, unsigned int infoSize )
{
	IORegistryEntry             *defaults;
	OSData                      *defaultObj;
	unsigned int                defaultSize;

	defaults = IORegistryEntry::fromPath( "/defaults", gIODTPlane );
	if (defaults == NULL) {
		return -1;
	}

	defaultObj = OSDynamicCast( OSData, defaults->getProperty(key));

	if (defaultObj == NULL) {
		defaults->release();
		return -1;
	}

	defaultSize = defaultObj->getLength();
	if (defaultSize > infoSize) {
		defaults->release();
		return -1;
	}

	memcpy( infoAddr, defaultObj->getBytesNoCopy(), defaultSize );

	defaults->release();
	return 0;
}

static void
FreePhysicalMemory( vm_offset_t * range )
{
	vm_offset_t virt;

	virt = ml_static_ptovirt( range[0] );
	if (virt) {
		ml_static_mfree( virt, range[1] );
	}
}

static IORegistryEntry *
MakeReferenceTable( DTEntry dtEntry, bool copy )
{
	IORegistryEntry             *regEntry;
	OSDictionary                *propTable;
	const OSSymbol              *nameKey;
	OSData                              *data;
	const OSSymbol              *sym;
	OpaqueDTPropertyIterator    dtIter;
	void const                  *prop;
	unsigned int                propSize;
	char const                                      *name;
	char                                location[32];
	bool                                noLocation = true;
	bool                                kernelOnly;

	regEntry = new IOService;

	if (regEntry && (false == regEntry->init())) {
		regEntry->release();
		regEntry = NULL;
	}

	if (regEntry &&
	    (kSuccess == SecureDTInitPropertyIterator( dtEntry, &dtIter))) {
		kernelOnly = (kSuccess == SecureDTGetProperty(dtEntry, "kernel-only", &prop, &propSize));
		propTable = regEntry->getPropertyTable();

		while (kSuccess == SecureDTIterateProperties( &dtIter, &name)) {
			if (kSuccess != SecureDTGetProperty( dtEntry, name, &prop, &propSize )) {
				continue;
			}

			if (copy) {
				nameKey = OSSymbol::withCString(name);
				data = OSData::withBytes(prop, propSize);
			} else {
				nameKey = OSSymbol::withCStringNoCopy(name);
				/* There is no OSDataConst or other way to indicate
				 * that the OSData is actually immutable. But CTRR
				 * will catch any write attempts. */
				data = OSData::withBytesNoCopy((void**)(uintptr_t)prop, propSize);
			}
			assert( nameKey && data );

			if (kernelOnly) {
				data->setSerializable(false);
			}

			propTable->setObject( nameKey, data);
			data->release();
			nameKey->release();

			if (nameKey == gIODTNameKey) {
				if (copy) {
					sym = OSSymbol::withCString((const char *) prop);
				} else {
					sym = OSSymbol::withCStringNoCopy((const char *) prop);
				}
				regEntry->setName( sym );
				sym->release();
			} else if (nameKey == gIODTUnitKey) {
				// all OF strings are null terminated... except this one
				if (propSize >= (int) sizeof(location)) {
					propSize = sizeof(location) - 1;
				}
				strncpy( location, (const char *) prop, propSize );
				location[propSize] = 0;
				regEntry->setLocation( location );
				propTable->removeObject( gIODTUnitKey );
				noLocation = false;
			} else if (noLocation && (!strncmp(name, "reg", sizeof("reg")))) {
				// default location - override later
				snprintf(location, sizeof(location), "%X", *((uint32_t *) prop));
				regEntry->setLocation( location );
			}
		}
	}

	return regEntry;
}

static void
AddPHandle( IORegistryEntry * regEntry )
{
	OSData *    data;

	if (regEntry->getProperty( gIODTInterruptCellKey)
	    && (data = OSDynamicCast( OSData, regEntry->getProperty( gIODTPHandleKey )))) {
		// a possible interrupt-parent
		gIODTPHandles->setObject( data );
		gIODTPHandleMap->setObject( regEntry );
	}
}

static LIBKERN_RETURNS_NOT_RETAINED IORegistryEntry *
FindPHandle( UInt32 phandle )
{
	OSData                      *data;
	IORegistryEntry *regEntry = NULL;
	int                         i;

	for (i = 0; (data = (OSData *)gIODTPHandles->getObject( i )); i++) {
		if (phandle == *((UInt32 *)data->getBytesNoCopy())) {
			regEntry = (IORegistryEntry *)
			    gIODTPHandleMap->getObject( i );
			break;
		}
	}

	return regEntry;
}

static bool
GetUInt32( IORegistryEntry * regEntry, const OSSymbol * name,
    UInt32 * value )
{
	OSObject * obj;
	OSData   * data;
	bool       result;

	if (!(obj = regEntry->copyProperty(name))) {
		return false;
	}

	result = ((data = OSDynamicCast(OSData, obj)) && (sizeof(UInt32) == data->getLength()));
	if (result) {
		*value = *((UInt32 *) data->getBytesNoCopy());
	}

	obj->release();
	return result;
}

static IORegistryEntry *
IODTFindInterruptParent( IORegistryEntry * regEntry, IOItemCount index )
{
	IORegistryEntry *   parent;
	UInt32              phandle;
	OSData          *   data;
	unsigned int        len;

	if ((data = OSDynamicCast( OSData, regEntry->getProperty( gIODTInterruptParentKey )))
	    && (sizeof(UInt32) <= (len = data->getLength()))) {
		if (((index + 1) * sizeof(UInt32)) > len) {
			index = 0;
		}
		phandle = ((UInt32 *) data->getBytesNoCopy())[index];
		parent = FindPHandle( phandle );
	} else if (NULL == regEntry->getProperty( "interrupt-controller")) {
		parent = regEntry->getParentEntry( gIODTPlane);
	} else {
		parent = NULL;
	}

	return parent;
}

const OSSymbol *
IODTInterruptControllerName( IORegistryEntry * regEntry )
{
	const OSSymbol      *sym;
	UInt32              phandle;
	bool                ok;
	char                buf[48];

	ok = GetUInt32( regEntry, gIODTPHandleKey, &phandle);
	assert( ok );

	if (ok) {
		snprintf(buf, sizeof(buf), "IOInterruptController%08X", (uint32_t)phandle);
		sym = OSSymbol::withCString( buf );
	} else {
		sym = NULL;
	}

	return sym;
}

#define unexpected(a) { kprintf("unexpected %s:%d\n", __FILE__, __LINE__); a; }

static void
IODTGetICellCounts( IORegistryEntry * regEntry,
    UInt32 * iCellCount, UInt32 * aCellCount)
{
	if (!GetUInt32( regEntry, gIODTInterruptCellKey, iCellCount)) {
		unexpected( *iCellCount = 1 );
	}
	if (!GetUInt32( regEntry, gIODTAddressCellKey, aCellCount)) {
		*aCellCount = 0;
	}
}

static UInt32
IODTMapOneInterrupt( IORegistryEntry * regEntry, UInt32 * intSpec, UInt32 index,
    LIBKERN_RETURNS_RETAINED OSData ** spec,
    LIBKERN_RETURNS_RETAINED const OSSymbol ** controller )
{
	IORegistryEntry *parent = NULL;
	OSData                      *data;
	UInt32                      *addrCmp;
	UInt32                      *maskCmp;
	UInt32                      *map;
	UInt32                      *endMap;
	UInt32                      acells, icells, pacells, picells, cell;
	UInt32                      i, original_icells;
	bool                        cmp, ok = false;

	parent = IODTFindInterruptParent( regEntry, index );
	IODTGetICellCounts( parent, &icells, &acells );
	addrCmp = NULL;
	if (acells) {
		data = OSDynamicCast( OSData, regEntry->getProperty( "reg" ));
		if (data && (data->getLength() >= (acells * sizeof(UInt32)))) {
			addrCmp = (UInt32 *) data->getBytesNoCopy();
		}
	}
	original_icells = icells;
	regEntry = parent;

	do {
#if IODTSUPPORTDEBUG
		kprintf("IODTMapOneInterrupt: current regEntry name %s\n", regEntry->getName());
		kprintf("acells - icells: ");
		for (i = 0; i < acells; i++) {
			kprintf("0x%08X ", addrCmp[i]);
		}
		kprintf("- ");
		for (i = 0; i < icells; i++) {
			kprintf("0x%08X ", intSpec[i]);
		}
		kprintf("\n");
#endif

		if (parent && (data = OSDynamicCast( OSData,
		    regEntry->getProperty( "interrupt-controller")))) {
			// found a controller - don't want to follow cascaded controllers
			parent = NULL;
			*spec = OSData::withBytesNoCopy((void *) intSpec,
			    icells * sizeof(UInt32));
			*controller = IODTInterruptControllerName( regEntry );
			ok = (*spec && *controller);
		} else if (parent && (data = OSDynamicCast( OSData,
		    regEntry->getProperty( "interrupt-map")))) {
			// interrupt-map
			map = (UInt32 *) data->getBytesNoCopy();
			endMap = map + (data->getLength() / sizeof(UInt32));
			data = OSDynamicCast( OSData, regEntry->getProperty( "interrupt-map-mask" ));
			if (data && (data->getLength() >= ((acells + icells) * sizeof(UInt32)))) {
				maskCmp = (UInt32 *) data->getBytesNoCopy();
			} else {
				maskCmp = NULL;
			}

#if IODTSUPPORTDEBUG
			if (maskCmp) {
				kprintf("        maskCmp: ");
				for (i = 0; i < acells + icells; i++) {
					if (i == acells) {
						kprintf("- ");
					}
					kprintf("0x%08X ", maskCmp[i]);
				}
				kprintf("\n");
				kprintf("         masked: ");
				for (i = 0; i < acells + icells; i++) {
					if (i == acells) {
						kprintf("- ");
					}
					kprintf("0x%08X ", ((i < acells) ? addrCmp[i] : intSpec[i - acells]) & maskCmp[i]);
				}
				kprintf("\n");
			} else {
				kprintf("no maskCmp\n");
			}
#endif
			do {
#if IODTSUPPORTDEBUG
				kprintf("            map: ");
				for (i = 0; i < acells + icells; i++) {
					if (i == acells) {
						kprintf("- ");
					}
					kprintf("0x%08X ", map[i]);
				}
				kprintf("\n");
#endif
				for (i = 0, cmp = true; cmp && (i < (acells + icells)); i++) {
					cell = (i < acells) ? addrCmp[i] : intSpec[i - acells];
					if (maskCmp) {
						cell &= maskCmp[i];
					}
					cmp = (cell == map[i]);
				}

				map += acells + icells;
				if (NULL == (parent = FindPHandle( *(map++)))) {
					unexpected(break);
				}

				IODTGetICellCounts( parent, &picells, &pacells );
				if (cmp) {
					addrCmp = map;
					intSpec = map + pacells;
					regEntry = parent;
				} else {
					map += pacells + picells;
				}
			} while (!cmp && (map < endMap));
			if (!cmp) {
				parent = NULL;
			}
		}

		if (parent) {
			IODTGetICellCounts( parent, &icells, &acells );
			regEntry = parent;
		}
	} while (parent);

	return ok ? original_icells : 0;
}

IOReturn
IODTGetInterruptOptions( IORegistryEntry * regEntry, int source, IOOptionBits * options )
{
	OSArray *   controllers;
	OSArray *   specifiers;
	OSArray *   shared;
	OSObject *  spec;
	OSObject *  oneSpec;

	*options = 0;

	controllers = OSDynamicCast(OSArray, regEntry->getProperty(gIOInterruptControllersKey));
	specifiers  = OSDynamicCast(OSArray, regEntry->getProperty(gIOInterruptSpecifiersKey));

	if (!controllers || !specifiers) {
		return kIOReturnNoInterrupt;
	}

	shared = (OSArray *) gIODTSharedInterrupts->getObject(
		(const OSSymbol *) controllers->getObject(source));
	if (!shared) {
		return kIOReturnSuccess;
	}

	spec = specifiers->getObject(source);
	if (!spec) {
		return kIOReturnNoInterrupt;
	}

	for (unsigned int i = 0;
	    (oneSpec = shared->getObject(i))
	    && (!oneSpec->isEqualTo(spec));
	    i++) {
	}

	if (oneSpec) {
		*options = kIODTInterruptShared;
	}

	return kIOReturnSuccess;
}

static bool
IODTMapInterruptsSharing( IORegistryEntry * regEntry, OSDictionary * allInts )
{
	IORegistryEntry *   parent;
	OSData *            local;
	OSData *            local2;
	UInt32 *            localBits;
	UInt32 *            localEnd;
	IOItemCount         index;
	OSData *            map = NULL;
	OSObject *          oneMap;
	OSArray *           mapped;
	OSArray *           controllerInts;
	const OSSymbol *    controller = NULL;
	OSArray *           controllers;
	UInt32              skip = 1;
	bool                ok, nw;

	nw = (NULL == (local = OSDynamicCast( OSData,
	    regEntry->getProperty( gIODTAAPLInterruptsKey))));
	if (nw && (NULL == (local = OSDynamicCast( OSData,
	    regEntry->getProperty( "interrupts"))))) {
		return true;  // nothing to see here
	}
	if (nw && (parent = regEntry->getParentEntry( gIODTPlane))) {
		// check for bridges on old world
		if ((local2 = OSDynamicCast( OSData,
		    parent->getProperty( gIODTAAPLInterruptsKey)))) {
			local = local2;
			nw = false;
		}
	}

	localBits = (UInt32 *) local->getBytesNoCopy();
	localEnd = localBits + (local->getLength() / sizeof(UInt32));
	index = 0;
	mapped = OSArray::withCapacity( 1 );
	controllers = OSArray::withCapacity( 1 );

	ok = (mapped && controllers);

	if (ok) {
		do {
			if (nw) {
				skip = IODTMapOneInterrupt( regEntry, localBits, index, &map, &controller );
				if (0 == skip) {
					IOLog("%s: error mapping interrupt[%d]\n",
					    regEntry->getName(), mapped->getCount());
					OSSafeReleaseNULL(map);
					OSSafeReleaseNULL(controller);
					break;
				}
			} else {
				map = OSData::withData( local, mapped->getCount() * sizeof(UInt32),
				    sizeof(UInt32));
				controller = gIODTDefaultInterruptController;
				controller->retain();
			}

			index++;
			localBits += skip;
			mapped->setObject( map );
			controllers->setObject( controller );

			if (allInts) {
				controllerInts = (OSArray *) allInts->getObject( controller );
				if (controllerInts) {
					for (unsigned int i = 0; (oneMap = controllerInts->getObject(i)); i++) {
						if (map->isEqualTo(oneMap)) {
							controllerInts = (OSArray *) gIODTSharedInterrupts->getObject( controller );
							if (controllerInts) {
								controllerInts->setObject(map);
							} else {
								controllerInts = OSArray::withObjects((const OSObject **) &map, 1, 4 );
								if (controllerInts) {
									gIODTSharedInterrupts->setObject( controller, controllerInts );
									controllerInts->release();
								}
							}
							break;
						}
					}
					if (!oneMap) {
						controllerInts->setObject(map);
					}
				} else {
					controllerInts = OSArray::withObjects((const OSObject **) &map, 1, 16 );
					if (controllerInts) {
						allInts->setObject( controller, controllerInts );
						controllerInts->release();
					}
				}
			}

			OSSafeReleaseNULL(map);
			OSSafeReleaseNULL(controller);
		} while (localBits < localEnd);
	}

	ok &= (localBits == localEnd);

	if (ok) {
		// store results
		ok  = regEntry->setProperty( gIOInterruptControllersKey, controllers);
		ok &= regEntry->setProperty( gIOInterruptSpecifiersKey, mapped);
	}

	if (controllers) {
		controllers->release();
	}
	if (mapped) {
		mapped->release();
	}

	return ok;
}

bool
IODTMapInterrupts( IORegistryEntry * regEntry )
{
	return IODTMapInterruptsSharing( regEntry, NULL );
}

/*
 */

static bool
CompareKey( OSString * key,
    const IORegistryEntry * table, const OSSymbol * propName,
    LIBKERN_RETURNS_RETAINED OSString ** matchingName )
{
	OSObject            *prop;
	OSData                      *data;
	OSString            *string;
	const char          *ckey;
	UInt32                      keyLen;
	UInt32          nlen;
	const char          *names;
	const char          *lastName;
	bool                        wild;
	bool                        matched;
	const char          *result = NULL;

	if (NULL == (prop = table->copyProperty( propName ))) {
		return 0;
	}

	if ((data = OSDynamicCast( OSData, prop ))) {
		names = (const char *) data->getBytesNoCopy();
		lastName = names + data->getLength();
	} else if ((string = OSDynamicCast( OSString, prop ))) {
		names = string->getCStringNoCopy();
		lastName = names + string->getLength() + 1;
	} else {
		names = NULL;
	}

	if (names) {
		ckey = key->getCStringNoCopy();
		keyLen = key->getLength();
		wild = ('*' == key->getChar( keyLen - 1 ));

		do {
			// for each name in the property
			nlen = (unsigned int) strnlen(names, lastName - names);
			if (wild) {
				matched = ((nlen >= (keyLen - 1)) && (0 == strncmp(ckey, names, keyLen - 1)));
			} else {
				matched = (keyLen == nlen) && (0 == strncmp(ckey, names, keyLen));
			}

			if (matched) {
				result = names;
			}

			names = names + nlen + 1;
		} while ((names < lastName) && (false == matched));
	}

	if (result && matchingName) {
		*matchingName = OSString::withCString( result );
	}

	if (prop) {
		prop->release();
	}

	return result != NULL;
}


bool
IODTCompareNubName( const IORegistryEntry * regEntry,
    OSString * name, OSString ** matchingName )
{
	bool matched;

	matched = CompareKey( name, regEntry, gIODTNameKey, matchingName)
	    || CompareKey( name, regEntry, gIODTCompatibleKey, matchingName)
	    || CompareKey( name, regEntry, gIODTTypeKey, matchingName)
	    || CompareKey( name, regEntry, gIODTModelKey, matchingName);

	return matched;
}

bool
IODTCompareNubName( const IORegistryEntry * regEntry,
    OSString * name, OSSharedPtr<OSString>& matchingName )
{
	OSString* matchingNameRaw = NULL;
	bool result = IODTCompareNubName(regEntry, name, &matchingNameRaw);
	matchingName.reset(matchingNameRaw, OSNoRetain);
	return result;
}

bool
IODTMatchNubWithKeys( IORegistryEntry * regEntry,
    const char * keys )
{
	OSObject    *obj;
	bool                result = false;

	obj = OSUnserialize( keys, NULL );

	if (obj) {
		result = regEntry->compareNames( obj );
		obj->release();
	}
#if DEBUG
	else {
		IOLog("Couldn't unserialize %s\n", keys );
	}
#endif

	return result;
}

OSCollectionIterator *
IODTFindMatchingEntries( IORegistryEntry * from,
    IOOptionBits options, const char * keys )
{
	OSSet                                       *result = NULL;
	IORegistryEntry                     *next;
	IORegistryIterator          *iter;
	OSCollectionIterator        *cIter;
	bool                                        cmp;
	bool                                        minus = options & kIODTExclusive;


	iter = IORegistryIterator::iterateOver( from, gIODTPlane,
	    (options & kIODTRecursive) ? kIORegistryIterateRecursively : 0 );
	if (iter) {
		do {
			if (result) {
				result->release();
			}
			result = OSSet::withCapacity( 3 );
			if (!result) {
				break;
			}

			iter->reset();
			while ((next = iter->getNextObject())) {
				// Look for existence of a debug property to skip
				if (next->getProperty("AAPL,ignore")) {
					continue;
				}

				if (keys) {
					cmp = IODTMatchNubWithKeys( next, keys );
					if ((minus && (false == cmp))
					    || ((false == minus) && (false != cmp))) {
						result->setObject( next);
					}
				} else {
					result->setObject( next);
				}
			}
		} while (!iter->isValid());

		iter->release();
	}

	cIter = OSCollectionIterator::withCollection( result);
	if (result) {
		result->release();
	}

	return cIter;
}


void
IODTSetResolving( IORegistryEntry *        regEntry,
    IODTCompareAddressCellFunc      compareFunc,
    IODTNVLocationFunc              locationFunc __unused )
{
	IODTPersistent * entry;
	IODTPersistent * newResolvers;
	OSNumber       * num;
	unsigned int     index;

	IOLockLock(gIODTResolvers->lock);

	entry = gIODTResolvers->resolvers;
	for (index = 0; index < gIODTResolvers->count; index++) {
		if (compareFunc == entry->compareFunc) {
			break;
		}
		entry++;
	}

	if (index == gIODTResolvers->count) {
		if (gIODTResolvers->alloc == gIODTResolvers->count) {
			if (__improbable(os_mul_overflow(gIODTResolvers->alloc, 2,
			    &gIODTResolvers->alloc))) {
				panic("IODTSetResolving - gIODTResolvers alloc overflows");
			}

			newResolvers = IONewZero(IODTPersistent, gIODTResolvers->alloc);
			if (__improbable(!newResolvers)) {
				panic("IODTSetResolving - could not allocate new resolvers");
			}

			bcopy(gIODTResolvers->resolvers, newResolvers,
			    sizeof(gIODTResolvers->resolvers[0]) * gIODTResolvers->count);

			IODelete(gIODTResolvers->resolvers, IODTPersistent,
			    gIODTResolvers->count);
			gIODTResolvers->resolvers = newResolvers;
		}

		entry = &gIODTResolvers->resolvers[gIODTResolvers->count];
		entry->compareFunc = compareFunc;
		gIODTResolvers->count++;
	}

	IOLockUnlock(gIODTResolvers->lock);

	num = OSNumber::withNumber(index, 32);
	regEntry->setProperty(gIODTPersistKey, num);
	OSSafeReleaseNULL(num);

	return;
}

#if  defined(__arm64__)
static SInt64
DefaultCompare( UInt32 cellCount, UInt32 left[], UInt32 right[] )
{
	SInt64 diff = 0;

	if (cellCount == 2) {
		diff = IOPhysical32(left[1], left[0]) - IOPhysical32(right[1], right[0]);
	} else if (cellCount == 1) {
		diff = (left[0] - right[0]);
	} else {
		panic("DefaultCompare only knows how to handle 1 or 2 cells.");
	}

	return diff;
}
#elif defined(__arm__) || defined(__i386__) || defined(__x86_64__)
static SInt32
DefaultCompare( UInt32 cellCount, UInt32 left[], UInt32 right[] )
{
	cellCount--;
	return left[cellCount] - right[cellCount];
}
#else
#error Unknown architecture.
#endif

static void
AddLengthToCells( UInt32 numCells, UInt32 *cells, UInt64 offset)
{
	if (numCells == 1) {
		cells[0] += (UInt32)offset;
	} else {
#if defined(__arm64__) || defined(__arm__)
		UInt64 sum = cells[numCells - 2] + offset;
		cells[numCells - 2] = (UInt32)sum;
		if (sum > UINT32_MAX) {
			cells[numCells - 1] += (UInt32)(sum >> 32);
		}
#else
		UInt64 sum = cells[numCells - 1] + offset;
		cells[numCells - 1] = (UInt32)sum;
		if (sum > UINT32_MAX) {
			cells[numCells - 2] += (UInt32)(sum >> 32);
		}
#endif
	}
}

static IOPhysicalAddress
CellsValue( UInt32 numCells, UInt32 *cells)
{
	if (numCells == 1) {
		return IOPhysical32( 0, cells[0] );
	} else {
#if defined(__arm64__) || defined(arm)
		return IOPhysical32( cells[numCells - 1], cells[numCells - 2] );
#else
		return IOPhysical32( cells[numCells - 2], cells[numCells - 1] );
#endif
	}
}

void
IODTGetCellCounts( IORegistryEntry * regEntry,
    UInt32 * sizeCount, UInt32 * addressCount)
{
	if (!GetUInt32( regEntry, gIODTSizeCellKey, sizeCount)) {
		*sizeCount = 1;
	}
	if (!GetUInt32( regEntry, gIODTAddressCellKey, addressCount)) {
		*addressCount = 2;
	}
	return;
}

// Given addr & len cells from our child, find it in our ranges property, then
// look in our parent to resolve the base of the range for us.

// Range[]: child-addr  our-addr  child-len
// #cells:    child       ours     child

bool
IODTResolveAddressCell( IORegistryEntry * startEntry,
    UInt32 cellsIn[],
    IOPhysicalAddress * phys, IOPhysicalLength * lenOut )
{
	IORegistryEntry     * parent = NULL;
	IORegistryEntry * regEntry;
	OSData          * prop;
	OSNumber    * num;
	unsigned int  index;
	// cells in addresses at regEntry
	UInt32              sizeCells, addressCells;
	// cells in addresses below regEntry
	UInt32              childSizeCells, childAddressCells;
	UInt32              childCells;
	UInt32              cell[8], propLen;
	UInt64              offset = 0;
	UInt32              endCell[8];
	UInt32              *range;
	UInt32              *lookRange;
	UInt32              *startRange;
	UInt32              *endRanges;
	bool                ok = true;
	SInt64              diff, diff2, endDiff;
	UInt64              len, rangeLen;

	IODTCompareAddressCellFunc  compare;

	regEntry = startEntry;
	regEntry->retain();
	IODTGetCellCounts( regEntry, &childSizeCells, &childAddressCells );
	childCells = childAddressCells + childSizeCells;

	if (childCells > sizeof(cell) / sizeof(cell[0])) {
		panic("IODTResolveAddressCell: Invalid device tree (%u,%u)", (uint32_t)childAddressCells, (uint32_t)childSizeCells);
	}

	bcopy( cellsIn, cell, sizeof(UInt32) * childCells );
	*lenOut = CellsValue( childSizeCells, cellsIn + childAddressCells );

	do{
		prop = OSDynamicCast( OSData, regEntry->getProperty( gIODTRangeKey ));
		if (NULL == prop) {
			/* end of the road */
			*phys = CellsValue( childAddressCells, cell );
			*phys += offset;
			break;
		}

		parent = regEntry->copyParentEntry( gIODTPlane );
		IODTGetCellCounts( parent, &sizeCells, &addressCells );

		if ((propLen = prop->getLength())) {
			// search
			startRange = (UInt32 *) prop->getBytesNoCopy();
			range = startRange;
			endRanges = range + (propLen / sizeof(UInt32));

			compare = NULL;
			num = OSDynamicCast(OSNumber, regEntry->getProperty(gIODTPersistKey));
			if (num) {
				IOLockLock(gIODTResolvers->lock);
				index = num->unsigned32BitValue();
				if (index < gIODTResolvers->count) {
					compare = gIODTResolvers->resolvers[index].compareFunc;
				}
				IOLockUnlock(gIODTResolvers->lock);
			}

			if (!compare && (addressCells == childAddressCells)) {
				compare = DefaultCompare;
			}
			if (!compare) {
				panic("There is no mixed comparison function yet...");
			}

			for (ok = false;
			    range < endRanges;
			    range += (childCells + addressCells)) {
				// is cell start within range?
				diff = (*compare)( childAddressCells, cell, range );

				if (childAddressCells > sizeof(endCell) / sizeof(endCell[0])) {
					panic("IODTResolveAddressCell: Invalid device tree (%u)", (uint32_t)childAddressCells);
				}

				bcopy(range, endCell, childAddressCells * sizeof(UInt32));

				rangeLen = CellsValue(childSizeCells, range + childAddressCells + addressCells);
				AddLengthToCells(childAddressCells, endCell, rangeLen);

				diff2 = (*compare)( childAddressCells, cell, endCell );

				// if start of cell < start of range, or end of range >= start of cell, skip
				if ((diff < 0) || (diff2 >= 0)) {
					continue;
				}

				len = CellsValue(childSizeCells, cell + childAddressCells);
				ok = (0 == len);

				if (!ok) {
					// search for cell end
					bcopy(cell, endCell, childAddressCells * sizeof(UInt32));

					AddLengthToCells(childAddressCells, endCell, len - 1);

					for (lookRange = startRange;
					    lookRange < endRanges;
					    lookRange += (childCells + addressCells)) {
						// make sure end of cell >= range start
						endDiff = (*compare)( childAddressCells, endCell, lookRange );
						if (endDiff < 0) {
							continue;
						}

						UInt64 rangeStart = CellsValue(addressCells, range + childAddressCells);
						UInt64 lookRangeStart = CellsValue(addressCells, lookRange + childAddressCells);
						if ((endDiff - len + 1 + lookRangeStart) == (diff + rangeStart)) {
							ok = true;
							break;
						}
					}
					if (!ok) {
						continue;
					}
				}
				offset += diff;
				break;
			}

			if (addressCells + sizeCells > sizeof(cell) / sizeof(cell[0])) {
				panic("IODTResolveAddressCell: Invalid device tree (%u, %u)", (uint32_t)addressCells, (uint32_t)sizeCells);
			}

			// Get the physical start of the range from our parent
			bcopy( range + childAddressCells, cell, sizeof(UInt32) * addressCells );
			bzero( cell + addressCells, sizeof(UInt32) * sizeCells );
		} /* else zero length range => pass thru to parent */

		OSSafeReleaseNULL(regEntry);
		regEntry                = parent;
		parent = NULL;
		childSizeCells          = sizeCells;
		childAddressCells       = addressCells;
		childCells              = childAddressCells + childSizeCells;
	}while (ok && regEntry);

	OSSafeReleaseNULL(regEntry);

	return ok;
}


OSArray *
IODTResolveAddressing( IORegistryEntry * regEntry,
    const char * addressPropertyName,
    IODeviceMemory * parent )
{
	IORegistryEntry             *parentEntry;
	OSData                              *addressProperty;
	UInt32                              sizeCells, addressCells, cells;
	int                                 i, num;
	UInt32                              *reg;
	IOPhysicalAddress   phys;
	IOPhysicalLength    len;
	OSArray                             *array;

	array = NULL;
	do{
		parentEntry = regEntry->copyParentEntry( gIODTPlane );
		addressProperty = (OSData *) regEntry->getProperty( addressPropertyName );
		if ((NULL == addressProperty) || (NULL == parentEntry)) {
			break;
		}

		IODTGetCellCounts( parentEntry, &sizeCells, &addressCells );
		if (0 == sizeCells) {
			break;
		}

		cells = sizeCells + addressCells;
		reg = (UInt32 *) addressProperty->getBytesNoCopy();
		num = addressProperty->getLength() / (4 * cells);

		array = OSArray::withCapacity( 1 );
		if (NULL == array) {
			break;
		}

		for (i = 0; i < num; i++) {
			if (IODTResolveAddressCell( parentEntry, reg, &phys, &len )) {
				IODeviceMemory *range;
				range = NULL;
				if (parent) {
					range = IODeviceMemory::withSubRange( parent,
					    phys - parent->getPhysicalSegment(0, NULL, kIOMemoryMapperNone), len );
				}
				if (NULL == range) {
					range = IODeviceMemory::withRange( phys, len );
				}
				if (range) {
					array->setObject( range );
					OSSafeReleaseNULL(range);
				}
			}
			reg += cells;
		}

		regEntry->setProperty( gIODeviceMemoryKey, array);
		array->release(); /* ??? */
	}while (false);

	OSSafeReleaseNULL(parentEntry);

	return array;
}

OSData *
IODTFindSlotName( IORegistryEntry * regEntry, UInt32 deviceNumber )
{
	IORegistryEntry             *parent;
	OSData                              *data;
	OSData                              *ret = NULL;
	UInt32                              *bits;
	UInt32                              i;
	UInt32              nlen;
	char                                *names;
	char                                *lastName;
	UInt32                              mask;

	data = (OSData *) regEntry->getProperty("AAPL,slot-name");
	if (data) {
		return data;
	}

	do{
		parent = regEntry->copyParentEntry( gIODTPlane );
		if (!parent) {
			break;
		}

		data = OSDynamicCast( OSData, parent->getProperty("slot-names"));
		if (!data) {
			break;
		}
		if (data->getLength() <= 4) {
			break;
		}

		bits = (UInt32 *) data->getBytesNoCopy();
		mask = *bits;
		if ((0 == (mask & (1 << deviceNumber)))) {
			break;
		}

		names = (char *)(bits + 1);
		lastName = names + (data->getLength() - 4);

		for (i = 0; (i <= deviceNumber) && (names < lastName); i++) {
			if (mask & (1 << i)) {
				nlen = 1 + ((unsigned int) strnlen(names, lastName - names));
				if (i == deviceNumber) {
					data = OSData::withBytesNoCopy(names, nlen);
					if (data) {
						regEntry->setProperty("AAPL,slot-name", data);
						ret = data;
						data->release();
					}
				} else {
					names += nlen;
				}
			}
		}
	}while (false);

	OSSafeReleaseNULL(parent);

	return ret;
}

extern "C" IOReturn
IONDRVLibrariesInitialize( IOService * provider )
{
	return kIOReturnUnsupported;
}