// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

#include "memmodel.h"

#include "mm.h"

#include "mmu.h"

#include "mpdalloc.h"

#include "mobject.h"

#include "cache_maintenance.inl"

// check enough space for page directories...

__ASSERT_COMPILE(KNumOsAsids <= (KPageDirectoryEnd-KPageDirectoryBase)/KPageDirectorySize);

PageDirectoryAllocator PageDirectories;

const TUint KLocalPdShift = KPageDirectoryShift > KPageShift ? KPageDirectoryShift-1 : KPageShift;

const TUint KLocalPdSize = 1<<KLocalPdShift;

const TUint KLocalPdPages = 1<<(KLocalPdShift-KPageShift);

__ASSERT_COMPILE((KPageDirectoryBase&(31*KPageDirectorySize))==0); // following code assumes this alignment

void PageDirectoryAllocator::GlobalPdeChanged(TPde* aPde)

	{

	__NK_ASSERT_DEBUG(MmuLock::IsHeld());

	__NK_ASSERT_DEBUG(TLinAddr(aPde)>=KPageDirectoryBase);

	__NK_ASSERT_DEBUG(TLinAddr(aPde)<KPageDirectoryEnd);

	__NK_ASSERT_DEBUG(KLocalPdSize==(TUint)KPageDirectorySize); // shouldn't be called if we have separate global PDs

	TLinAddr addr = (TLinAddr(aPde)&KPageDirectoryMask)*(KChunkSize/sizeof(TPde));

	if(addr<KGlobalMemoryBase)

		return; // change was in local part of PD, so nothing to do

	if(addr-KIPCAlias<KIPCAliasAreaSize)

		return; // change was in IPC alias area, so nothing to do

	if(!iAllocator)

		return; // not yet initialised

	TRACE2(("PageDirectoryAllocator::GlobalPdeChanged(0x%08x)",aPde));

	TPde pde = *aPde;

	TLinAddr pPde = KPageDirectoryBase+(TLinAddr(aPde)&KPageDirectoryMask); // first page directory

	// copy PDE to all allocated page directories

	pPde -= KPageDirectorySize; // start off at PD minus one

	TLinAddr lastPd = KPageDirectoryBase+(KNumOsAsids-1)*KPageDirectorySize;

	TUint32* ptr = iAllocator->iMap;

	do

		{

		TUint32 bits = ~*ptr++;

		do

			{

			pPde += KPageDirectorySize; // step to next page directory

			if(bits&0x80000000u)

				{

				TRACE2(("!PDE %x=%x",pPde,pde));

				*(TPde*)pPde = pde;

				CacheMaintenance::SinglePdeUpdated(pPde);

				}

			}

		while(bits<<=1);

		pPde |= 31*KPageDirectorySize; // step to next group of 32 PDs

		}

	while(pPde<lastPd);

	}

void PageDirectoryAllocator::Init2()

	{

	TRACEB(("PageDirectoryAllocator::Init2()"));

	// construct memory object for page directories...

#if defined(__CPU_PAGE_TABLES_FULLY_CACHED)

	TMemoryAttributes memAttr = EMemoryAttributeStandard;

#else

	TMemoryAttributes memAttr = (TMemoryAttributes)(EMemoryAttributeNormalUncached|EMemoryAttributeDefaultShareable);

#endif

	TInt r = MM::InitFixedKernelMemory(iPageDirectoryMemory, KPageDirectoryBase, KPageDirectoryEnd, KPageDirectorySize, EMemoryObjectHardware, EMemoryCreateNoWipe, memAttr, EMappingCreateFixedVirtual);

	__NK_ASSERT_ALWAYS(r==KErrNone);

	// initialise kernel page directory...

	TPhysAddr kernelPd = Mmu::LinearToPhysical((TLinAddr)Mmu::PageDirectory(KKernelOsAsid));

	iKernelPageDirectory = kernelPd;

	((DMemModelProcess*)K::TheKernelProcess)->iPageDir = kernelPd;

	AssignPages(KKernelOsAsid*(KPageDirectorySize>>KPageShift),KPageDirectorySize>>KPageShift,kernelPd);

	// construct allocator...

	iAllocator = TBitMapAllocator::New(KNumOsAsids,ETrue);

	__NK_ASSERT_ALWAYS(iAllocator);

	iAllocator->Alloc(KKernelOsAsid,1); // kernel page directory already allocated

	TRACEB(("PageDirectoryAllocator::Init2 done"));

	}

void PageDirectoryAllocator::AssignPages(TUint aIndex, TUint aCount, TPhysAddr aPhysAddr)

	{

	__NK_ASSERT_DEBUG(aCount<=KMaxPageInfoUpdatesInOneGo);

	MmuLock::Lock();

	SPageInfo* pi = SPageInfo::FromPhysAddr(aPhysAddr);

	SPageInfo* piEnd = pi+aCount;

	while(pi<piEnd)

		{

		pi->SetPhysAlloc(iPageDirectoryMemory,aIndex);

		++pi;

		++aIndex;

		}

	MmuLock::Unlock();

	}

TInt PageDirectoryAllocator::Alloc(TUint aOsAsid, TPhysAddr& aPageDirectory)

	{

	TRACE(("PageDirectoryAllocator::Alloc(%d)",aOsAsid));

	// get memory for local page directory...

	Mmu& m = TheMmu;

	TUint offset = aOsAsid*KPageDirectorySize;

	TPhysAddr pdPhys;

	RamAllocLock::Lock();

	TInt r = m.AllocContiguousRam(pdPhys, KLocalPdPages, KLocalPdShift-KPageShift, iPageDirectoryMemory->RamAllocFlags());

	if(r==KErrNone)

		{

		AssignPages(offset>>KPageShift,KLocalPdPages,pdPhys);

#ifdef BTRACE_KERNEL_MEMORY

		BTrace4(BTrace::EKernelMemory, BTrace::EKernelMemoryMiscAlloc, KLocalPdPages << KPageShift);

		Epoc::KernelMiscPages += KLocalPdPages;

#endif

		}

	RamAllocLock::Unlock();

	if(r==KErrNone)

		{

		TRACE(("PageDirectoryAllocator::Alloc pdPhys = 0x%08x",pdPhys));

		// map local page directory...

		r = MM::MemoryAddContiguous(iPageDirectoryMemory,MM::BytesToPages(offset),KLocalPdPages,pdPhys);

		if(r!=KErrNone)

			{

			RamAllocLock::Lock();

			m.FreeContiguousRam(pdPhys,KLocalPdPages);

#ifdef BTRACE_KERNEL_MEMORY

			BTrace4(BTrace::EKernelMemory, BTrace::EKernelMemoryMiscFree, KLocalPdPages << KPageShift);

			Epoc::KernelMiscPages -= KLocalPdPages;

#endif

			RamAllocLock::Unlock();

			}

		else

			{

			aPageDirectory = pdPhys;

			TPde* pd = Mmu::PageDirectory(aOsAsid);

			const TUint globalOffset = (KGlobalMemoryBase>>KChunkShift)*sizeof(TPde); // start of global part

			// clear local entries in page directory...

			memclr(pd,globalOffset);

			CacheMaintenance::PdesInitialised((TLinAddr)pd,globalOffset);

			if(KLocalPdSize<(TUint)KPageDirectorySize)

				{

				// map global page directory after local part...

				__NK_ASSERT_DEBUG(KLocalPdSize==globalOffset);

				r = MM::MemoryAddContiguous(iPageDirectoryMemory, MM::BytesToPages(offset+KLocalPdSize), 

						(KPageDirectorySize-KLocalPdSize)/KPageSize, iKernelPageDirectory+KLocalPdSize);

				__NK_ASSERT_DEBUG(r==KErrNone); // can't fail

				MmuLock::Lock(); // need lock because allocator not otherwise atomic

				iAllocator->Alloc(aOsAsid,1);

				MmuLock::Unlock();

				}

			else

				{

				// copy global entries to local page directory...

				TPde* globalPd = Mmu::PageDirectory(KKernelOsAsid);

				MmuLock::Lock(); // need lock because allocator not otherwise atomic, also  to make sure GlobalPdeChanged() only accesses extant PDs

				memcpy((TUint8*)pd+globalOffset,(TUint8*)globalPd+globalOffset,KPageDirectorySize-globalOffset);

				iAllocator->Alloc(aOsAsid,1);

				MmuLock::Unlock();

				CacheMaintenance::PdesInitialised((TLinAddr)((TUint8*)pd+globalOffset),KPageDirectorySize-globalOffset);

				}

			}

		}

	TRACE(("PageDirectoryAllocator::Alloc returns %d",r));

	return r;

	}

void PageDirectoryAllocator::Free(TUint aOsAsid)

	{

	TRACE(("PageDirectoryAllocator::Free(%d)",aOsAsid));

	MmuLock::Lock(); // need lock because allocator not otherwise atomic, also to make sure GlobalPdeChanged() only accesses extant PDs

	iAllocator->Free(aOsAsid, 1);

	MmuLock::Unlock();

	const TUint KPageDirectoryPageCount = KPageDirectorySize>>KPageShift;

	TPhysAddr pages[KPageDirectoryPageCount];

	TUint n = MM::MemoryRemovePages(iPageDirectoryMemory,aOsAsid*KPageDirectoryPageCount,KPageDirectoryPageCount,pages);

	(void)n;

	__NK_ASSERT_DEBUG(n==KPageDirectoryPageCount);

	RamAllocLock::Lock();

	Mmu& m = TheMmu;

	// Page directories are fixed.

	m.FreeRam(pages, KLocalPdPages, EPageFixed);

#ifdef BTRACE_KERNEL_MEMORY

	BTrace4(BTrace::EKernelMemory, BTrace::EKernelMemoryMiscFree, KLocalPdPages << KPageShift);

	Epoc::KernelMiscPages -= KLocalPdPages;

#endif

	RamAllocLock::Unlock();

	}