// 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:

// e32\memmodel\epoc\multiple\x86\xsched.cia

// 

//

#include <x86_mem.h>

GLDEF_C __NAKED__ void DoProcessSwitch()

	{

	// Enter with kernel locked

	// EBX = pointer to new thread (NThread)

	// EDI = pointer to TScheduler

	// ESI = pointer to TSubScheduler (SMP only)

	// Preserve ESI, EDI

	// eax = new process (DX86PlatProcess)

	asm("mov eax, [ebx+%0]": : "i"_FOFF(NThreadBase,iAddressSpace)); 

#ifdef __SMP__

	asm("cmp eax, [esi+%0]": :"i"_FOFF(TSubScheduler,iAddressSpace));

#else

	asm("cmp eax, [edi+%0]": : "i"_FOFF(TScheduler,iAddressSpace));

#endif

	asm("jz no_as_switch");

	asm("mov ecx, [eax+%0]": : "i"_FOFF(DMemModelProcess,iGlobalPageDir));

	asm("mov cr3, ecx");

#ifdef __SMP__

	asm("mov [esi+%0], eax": :"i"_FOFF(TSubScheduler,iAddressSpace));

#else

	asm("mov [edi+%0], eax": : "i"_FOFF(TScheduler,iAddressSpace));

#endif

	asm("no_as_switch:");

	// Get DThread* from NThread* (former contains latter so we go backwards in memory to get there)

	asm("mov ecx, 0");

	asm("lea ecx, [ecx+%0]": : "i"_FOFF(DThread,iNThread));

	asm("sub ebx, ecx");

	// check for memory being aliased...

	asm("mov ecx, [ebx+%0]": : "i"_FOFF(DMemModelThread,iAliasLinAddr));

	asm("cmp ecx, 0");

	asm("jz done");

	// restore alias...

	asm("mov edx, [ebx+%0]": : "i"_FOFF(DMemModelThread,iAliasPdePtr));

	asm("mov eax, [ebx+%0]": : "i"_FOFF(DMemModelThread,iAliasPde));

	asm("mov [edx], eax");

	asm("invlpg [ecx]");

	asm("done:");

	asm("ret");

	};