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

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

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

     5 // which accompanies this distribution, and is available

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

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

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

    15 // 

    16 //

    17 

    18 #include <x86_mem.h>

    19 

    20 GLDEF_C __NAKED__ void DoProcessSwitch()

    21 	{

    22 	// Enter with kernel locked

    23 	// EBX = pointer to new thread (NThread)

    24 	// EDI = pointer to TScheduler

    25 	// ESI = pointer to TSubScheduler (SMP only)

    26 	// Preserve ESI, EDI

    27 	// eax = new process (DX86PlatProcess)

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

    29 #ifdef __SMP__

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

    31 #else

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

    33 #endif

    34 	asm("jz no_as_switch");

    35 

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

    37 	asm("mov cr3, ecx");

    38 #ifdef __SMP__

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

    40 #else

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

    42 #endif

    43 

    44 	asm("no_as_switch:");

    45 

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

    47 	asm("mov ecx, 0");

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

    49 	asm("sub ebx, ecx");

    50 

    51 	// check for memory being aliased...

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

    53 	asm("cmp ecx, 0");

    54 	asm("jz done");

    55 

    56 	// restore alias...

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

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

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

    60 	asm("invlpg [ecx]");

    61 

    62 	asm("done:");

    63 	asm("ret");

    64 	};

    65