// Copyright (c) 1998-2009 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\nkern\arm\vectors.cia

// 

//

#define __INCLUDE_NTHREADBASE_DEFINES__

#include <e32cia.h>

#include <arm.h>

void FastMutexNestAttempt();

void FastMutexSignalError();

extern "C" void ExcFault(TAny*);

#ifdef __CPU_HAS_MMU

#define __USE_CP15_FAULT_INFO__

#endif

#ifdef _DEBUG

#define __CHECK_LOCK_STATE__

#endif

//#define __FAULT_ON_FIQ__

#ifdef __CHECK_LOCK_STATE__

// Check that the kernel is unlocked, no fast mutexes are held and that the thread is not in a

// critical section.  Called when returning to user mode

__NAKED__ void CheckLockState()

	{

	asm("stmfd sp!, {r14}");

	asm("ldr r12, __TheScheduler ");

	asm("ldr r14, [r12, #%a0]" : : "i" _FOFF(TScheduler,iKernCSLocked));

	asm("cmp r14, #0 ");

	asm("movne r12, #0xdd000000 ");

	asm("strne r12, [r12, #1] ");

	asm("ldr r12, [r12, #%a0]" : : "i" _FOFF(TScheduler,iCurrentThread));

	asm("ldr r14, [r12, #%a0]" : : "i" _FOFF(NThread,iHeldFastMutex));

	asm("cmp r14, #0 ");

	__CPOPRET(eq, "");

	asm("badLockState: ");

	asm("mov r12, #0xd7 ");

	asm("msr cpsr, r12 ");

	asm("mov r12, #0xdd000000 ");

	asm("str r12, [r12, #3] ");

	}

#endif

__ASSERT_COMPILE(EUserModeCallbackRun == 0);

__NAKED__ void CallUserModeCallbacks()

	{

	// called with interrupts disabled

	// preserves r0 and r1 in additional to usual registers

	// leaves current thread in r2

	// the vast majority of times this is called with zero or one callback pending

	asm(".global callUserModeCallbacks ");

	asm("callUserModeCallbacks: ");

	asm("ldr ip, __TheScheduler ");

	asm("ldr r2, [ip, #%a0]" : : "i" _FOFF(TScheduler, iCurrentThread));

	asm("callUserModeCallbacks2: ");

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("mrc p15, 0, r12, c3, c0, 0 ");

	asm("tst r12, #0xc0000000 ");

	asm("cdpne p15, 0, c0, c0, c0, 0 ");

#endif

#ifdef __CHECK_LOCK_STATE__

	asm("ldr ip, [r2, #%a0]" : : "i" _FOFF(NThread,iCsCount));

	asm("cmp ip, #0 ");

	asm("bne badLockState ");

#endif

	asm("ldr ip, [r2, #%a0]" : : "i" _FOFF(NThread, iUserModeCallbacks));

	asm("teq ip, #0");

	asm("bne 1f");

	__JUMP(,lr);

	asm("1: ");

	asm("stmfd sp!, {r0-r2, r4-r11, lr}");

	asm("movs r4, r3");

	// if r3 != 0 it is the user context type to set the thread to

	asm("strneb r3, [r2, #%a0]" : : "i" _FOFF(NThread, iUserContextType));

	// Remove first callback and enter critical section - we can just set iCsCount to 1 as we are

	// guaranteed not be be in a critical section already

	asm("ldmia ip, {r1, r3} ");		// HARDCODED: TUserModeCallback layout

    asm("mov r0, #1");

	asm("str r0, [r2, #%a0]" : : "i" _FOFF(NThread, iCsCount));

	asm("str r1, [r2, #%a0]" : : "i" _FOFF(NThread,iUserModeCallbacks));

	// Re-enable interrupts and call callback

	SET_MODE(r0, MODE_SVC, INTS_ALL_ON);

	asm("mov r1, #%a0 " : : "i" ((TInt)KUserModeCallbackUnqueued));

	asm("str r1, [ip, #%a0]" : : "i" _FOFF(TUserModeCallback, iNext));

	asm("mov r0, ip");

	asm("mov r1, #0 ");				// 0 == EUserModeCallbackRun

	__JUMPL(3);

	SET_MODE(r0, MODE_SVC, INTS_ALL_OFF);

	asm("movs r3, r4");

	// Leave critical section, avoid calling NKern::ThreadLeaveCS unless we have to

	asm("ldmfd sp!, {r0-r2, r4-r11, lr}");

	// reset user context type to undefined if r3 != 0

	asm("mov ip, #%a0" : : "i" (NThread::EContextUndefined));

	asm("strneb ip, [r2, #%a0]" : : "i" _FOFF(NThread, iUserContextType));

	asm("ldr ip, [r2, #%a0]" : : "i" _FOFF(NThread, iCsFunction));

	asm("teq ip, #0");

	asm("streq ip, [r2, #%a0]" : : "i" _FOFF(NThread, iCsCount));

	asm("beq callUserModeCallbacks2 ");

	asm("leaveCS:");

	asm("sub sp, sp, #48 ");

	SET_MODE(r0, MODE_SVC, INTS_ALL_ON);

	asm("bl " CSM_ZN5NKern13ThreadLeaveCSEv);

	SET_MODE(r0, MODE_SVC, INTS_ALL_OFF);

	asm("ldmfd sp!, {r0-r2, r4-r11, lr}");

	asm("b callUserModeCallbacks2 ");

	}

/***************************************************************************

 * SWI Handler

 ***************************************************************************/

extern "C" __NAKED__ void __ArmVectorSwi()

	{

	// IRQs disabled, FIQs enabled here

	asm("ldr r12, [lr, #-4] ");				// get SWI opcode

	asm("stmfd sp!, {r11, lr} ");			// save return address, r11 for 8 byte align

	USER_MEMORY_GUARD_ON_IF_MODE_USR(r11);

	asm("ldr r11, __TheScheduler ");	

	asm("adr lr, fast_swi_exit ");

	asm("movs r12, r12, lsl #9 ");			// 512*SWI number into r12

	asm("bcc slow_swi ");					// bit 23=0 for slow/unprot

	asm("ldr r1, [r11, #%a0]" : : "i" _FOFF(TScheduler,iCurrentThread));

	asm("beq wait_for_any_request ");		// special case for Exec::WaitForAnyRequest

#ifdef __CPU_ARM_HAS_CPS

	asm("ldr r2, [r1, #%a0]" : : "i" _FOFF(NThread,iFastExecTable));

	CPSIDIF;								// all interrupts off

	asm("ldr r3, [r2], r12, lsr #7 ");		// r3=limit, r2->dispatch table entry

	asm("ldr r2, [r2] ");					// r2->kernel function

	asm("cmp r3, r12, lsr #9 ");			// r3-SWI number

	__JUMP(hi, r2);							// if SWI number valid, call kernel function

#else

	SET_INTS(r2, MODE_SVC, INTS_ALL_OFF);

	asm("ldr r2, [r1, #%a0]" : : "i" _FOFF(NThread,iFastExecTable));

	asm("ldr r3, [r2], r12, lsr #7 ");		// r3=limit, r2->dispatch table entry

	asm("cmp r3, r12, lsr #9 ");			// r3-SWI number

	asm("ldrhi pc, [r2] ");					// if SWI number valid, call kernel function

#endif

	asm("mvn r12, #0 ");					// put invalid SWI number into r12

	asm("b slow_swi ");						// go through slow SWI routine to call invalid SWI handler

	asm("fast_swi_exit: ");

#ifdef __CHECK_LOCK_STATE__

	asm("mrs r12, spsr ");

	asm("tst r12, #0x0f ");

	asm("bleq  " CSM_Z14CheckLockStatev);

#endif

	USER_MEMORY_GUARD_OFF_IF_MODE_USR(r11);

	ERRATUM_353494_MODE_CHANGE(,r11);

	asm("ldmfd sp!, {r11, pc}^ ");			// return and restore cpsr

	asm("slow_swi: ");						// IRQs off, FIQs on here

	asm("stmfd sp!, {r3-r10} ");			// save nonvolatile registers, r3 for 8 byte align

	asm("ldr r9, [r11, #%a0]" : : "i" _FOFF(TScheduler,iCurrentThread));	// r9->current thread

	SET_INTS(lr, MODE_SVC, INTS_ALL_ON);	// all interrupts on

	asm("mov r10, r11 ");					// r10->scheduler

	asm("ldr r4, [r9, #%a0]" : : "i" _FOFF(NThread,iSlowExecTable));

	asm("mrs r11, spsr ");					// spsr_svc into r11

	asm("adr lr, slow_swi_exit ");

	asm("add r6, r4, r12, lsr #6 ");		// r6->dispatch table entry

	asm("ldr r5, [r4, #-12] ");				// r5=limit

	SET_INTS_1(r7, MODE_SVC, INTS_ALL_OFF);

	asm("cmp r5, r12, lsr #9 ");			// r5-SWI number

	asm("ldmhiia r6, {r5,r6} ");			// if SWI number OK, flags into r5, function addr into r6

	asm("ldrls pc, [r4, #-8] ");			// if SWI number invalid, call invalid handler

	asm("tst r5, #%a0" : : "i" ((TInt)KExecFlagExtraArgMask));	// extra arguments needed?

	asm("addne r2, sp, #4 ");				// if so, point r2 at saved registers on stack

	asm("tst r5, #%a0" : : "i" ((TInt)KExecFlagClaim));			// claim system lock?

	asm("beq slow_swi_no_wait ");			// skip if not

	SET_INTS_2(r7, MODE_SVC, INTS_ALL_OFF);	// interrupts off

#ifdef _DEBUG

	asm("ldr r12, [r9, #%a0]" : : "i" _FOFF(NThread,iHeldFastMutex));

	asm("cmp r12, #0 ");

	asm("bne  " CSM_Z20FastMutexNestAttemptv);	// debug check that current thread doesn't already hold a fast mutex

#endif

	asm("ldr r12, [r10, #%a0]!" : : "i" _FOFF(TScheduler,iLock.iHoldingThread));	// r12=iLock.iHoldingThread

	SET_INTS_1(r7, MODE_SVC, INTS_ALL_ON);

	asm("cmp r12, #0 ");					// is system lock already held?

	asm("bne ss_fast_mutex_held ");			// branch if it is

	asm("ss_fast_mutex_obtained: ");

	asm("str r10, [r9, #%a0]" : : "i" _FOFF(NThread,iHeldFastMutex));	// current thread->iHeldFastMutex=&iLock

	asm("str r9, [r10], #-%a0" : : "i" _FOFF(TScheduler,iLock));		// iLock.iHoldingThread=current thread, r10->scheduler

#ifdef BTRACE_FAST_MUTEX

	asm("ldrb r12, [r10,#%a0]" : : "i" (_FOFF(TScheduler,iFastMutexFilter)));

	asm("cmp r12, #0");

	asm("bne syslock_trace_wait");

	asm("syslock_trace_wait_done:");

#endif

	SET_INTS_2(r7, MODE_SVC, INTS_ALL_ON);	// all interrupts on

	asm("slow_swi_no_wait: ");

	asm("tst r5, #%a0" : : "i" ((TInt)KExecFlagPreprocess));	// preprocess (handle lookup)? can use r4, r7, r8, r12, r0

	asm("mov lr, pc ");

	asm("ldrne pc, [r4, #-4] ");			// call preprocess handler if required

	asm("mov lr, pc ");

	__JUMP(,r6);							// call exec function, preserve r5,r11 if release syslock not required

											// preserve r5,r9,r10,r11 if release required

	asm("tst r5, #%a0" : : "i" ((TInt)KExecFlagRelease));		// release system lock?

	asm("beq slow_swi_exit ");				// skip if not

	SET_INTS(r12, MODE_SVC, INTS_ALL_OFF);	// disable interrupts

#ifdef _DEBUG

	asm("add r8, r10, #%a0" : : "i" _FOFF(TScheduler,iLock));

	asm("ldr r12, [r9, #%a0]" : : "i" _FOFF(NThread,iHeldFastMutex));

	asm("cmp r12, r8 ");

	asm("bne  " CSM_Z20FastMutexSignalErrorv);	// debug check that current thread holds system lock

#endif

#ifdef BTRACE_FAST_MUTEX

	asm("ldrb r12, [r10,#%a0]" : : "i" (_FOFF(TScheduler,iFastMutexFilter)));

	asm("cmp r12, #0");

	asm("bne syslock_trace_signal");

	asm("syslock_trace_signal_done:");

#endif

	asm("mov r12, #0 ");

	asm("str r12, [r10, #%a0]" : : "i" _FOFF(TScheduler,iLock.iHoldingThread));	// iLock.iHoldingThread=NULL

	asm("str r12, [r9, #%a0]" : : "i" _FOFF(NThread,iHeldFastMutex));			// current thread->iHeldFastMutex=NULL

	asm("ldr r3, [r10, #%a0]" : : "i" _FOFF(TScheduler,iLock.iWaiting));		// r3=iLock.iWaiting

	asm("str r12, [r10, #%a0]" : : "i" _FOFF(TScheduler,iLock.iWaiting));		// iLock.iWaiting=0

	SET_INTS_1(r8, MODE_SVC, INTS_ALL_ON);

	asm("cmp r3, #0 ");						// check waiting flag

	asm("bne ss_signal_check ");			// branch if set

	asm("ss_signal_done: ");

	SET_INTS_2(r8, MODE_SVC, INTS_ALL_ON);	// otherwise reenable interrupts

	asm("slow_swi_exit: ");

#ifdef __CHECK_LOCK_STATE__

	asm("tst r11, #0x0f ");

	asm("bleq  " CSM_Z14CheckLockStatev);

#endif

	SET_INTS(r12, MODE_SVC, INTS_ALL_OFF);	// disable interrupts

	asm("msr spsr, r11 ");					// restore spsr_svc

	asm("tst r11, #0x0f ");

	asm("mov r3, #0 ");

#if defined(__CPU_CORTEX_A9__) && !defined(__CPU_ARM_A9_ERRATUM_571622_FIXED)

	asm("nop ");							// ARM Cortex-A9 MPCore erratum 571622 workaround

											// Insert nops so branch doesn't occur in 2nd or 3rd position after a msr spsr

#endif

	asm("bleq callUserModeCallbacks ");		// call user-mode callbacks	

	USER_MEMORY_GUARD_OFF_IF_MODE_USR(r11);

	ERRATUM_353494_MODE_CHANGE(,r11);

	asm("ldmfd sp!, {r3-r11,pc}^ ");		// return from EXEC function

	// Come here if we need to wait for the system lock

	// r9->current thread, r10=&iLock, r12=iLock.iHoldingThread

	asm("ss_fast_mutex_held: ");

	asm("mov r8, #1 ");

	asm("str r8, [r10, #%a0]" : : "i" (_FOFF(TScheduler,iKernCSLocked)-_FOFF(TScheduler,iLock)));	// lock the kernel

	SET_INTS_2(r7, MODE_SVC, INTS_ALL_ON);	// enable interrupts

	asm("str r8, [r10, #4] ");				// iWaiting=1

	asm("str r10, [r9, #%a0]" : : "i" _FOFF(NThread,iWaitFastMutex));	// current thread->iWaitFastMutex=&iLock

	asm("stmfd sp!, {r0-r3} ");				// save exec call arguments

	asm("mov r0, r12 ");					// parameter for YieldTo

	ASM_DEBUG1(NKFMWaitYield,r0);

	asm("bl  " CSM_ZN10TScheduler7YieldToEP11NThreadBase);		// yield to the mutex holding thread

	// will not return until the mutex is free

	// on return r0=Scheduler,r1=0,r2!=0,r3=current thread, kernel unlocked, interrupts disabled

	asm("str r1, [r9, #%a0]" : : "i" _FOFF(NThread,iWaitFastMutex));	// iWaitFastMutex=NULL

	asm("ldmfd sp!, {r0-r3} ");				// retrieve exec call arguments

	asm("b ss_fast_mutex_obtained ");		// branch back to main code path

	// Come here if we need to reschedule after releasing the system lock

	// kernel unlocked, interrupts enabled, r0 contains return value from Exec call

	// r9->current thread, r10=&TheScheduler, r3=1, r8=0x13

	asm("ss_signal_check: ");

	asm("str r3, [r10, #%a0]" : : "i" _FOFF(TScheduler,iKernCSLocked));	// lock the kernel (assumes iWaiting always 0 or 1)

	SET_INTS_2(r8, MODE_SVC, INTS_ALL_ON);	// reenable interrupts

	asm("strb r3, [r10, #%a0]" : : "i" _FOFF(TScheduler,iRescheduleNeededFlag));

	asm("ldr r3, [r9, #%a0]" : : "i" _FOFF(NThread,iCsFunction));	// r3=current thread->iCsFunction

	asm("ldr r2, [r9, #%a0]" : : "i" _FOFF(NThread,iCsCount));		// r2=current thread->iCsCount

	asm("mov r4, r0 ");						// save return value

	asm("cmp r3, #0 ");						// outstanding CS function?

	asm("beq 2f ");							// branch if not

	asm("cmp r2, #0 ");						// iCsCount!=0 ?

	asm("moveq r0, r9 ");					// if iCsCount=0, DoCsFunction()

	asm("bleq  " CSM_ZN11NThreadBase12DoCsFunctionEv);

	asm("2: ");

	asm("bl  " CSM_ZN10TScheduler10RescheduleEv);	// reschedule to allow waiting thread in

	asm("mov r0, r4 ");						// recover return value

	asm("b ss_signal_done ");				// branch back to main code path

#ifdef BTRACE_FAST_MUTEX

	asm("syslock_trace_wait:");

	asm("ldr r12, [sp,#9*4]"); // r12 = return address from SWI

	asm("mov r8, r3"); // save r3

	asm("stmdb sp!,{r0-r2,r12}"); // 4th item on stack is PC value for trace

	asm("ldr r0, fmwait_trace_header");

	asm("mov r2, r9"); // current thread

	asm("add r3, r10, #%a0" : : "i" _FOFF(TScheduler,iLock));

	asm("mov lr, pc");

	asm("ldr pc, [r10, #%a0]" : : "i" _FOFF(TScheduler,iBTraceHandler));	

	asm("ldmia sp!,{r0-r2,r12}");

	asm("mov r3, r8"); // restore r3

	asm("b syslock_trace_wait_done");

	asm("syslock_trace_signal:");

	asm("ldr r12, [sp,#9*4]"); // r12 = return address from SWI

	asm("stmdb sp!,{r0-r2,r12}"); // 4th item on stack is PC value for trace

	asm("ldr r0, fmsignal_trace_header");

	asm("mov r2, r9"); // current thread

	asm("add r3, r10, #%a0" : : "i" _FOFF(TScheduler,iLock));

	asm("mov lr, pc");

	asm("ldr pc, [r10, #%a0]" : : "i" _FOFF(TScheduler,iBTraceHandler));	

	asm("ldmia sp!,{r0-r2,r12}");

	asm("b syslock_trace_signal_done");

	asm("fmsignal_trace_header:");

	asm(".word %a0" : : "i" ((TInt)(16<<BTrace::ESizeIndex) + ((BTrace::EContextIdPresent|BTrace::EPcPresent) << BTrace::EFlagsIndex*8) + (BTrace::EFastMutex<< BTrace::ECategoryIndex*8) + (BTrace::EFastMutexSignal << BTrace::ESubCategoryIndex*8)) );

	asm("fmwait_trace_header:");

	asm(".word %a0" : : "i" ((TInt)(16<<BTrace::ESizeIndex) + ((BTrace::EContextIdPresent|BTrace::EPcPresent) << BTrace::EFlagsIndex*8) + (BTrace::EFastMutex << BTrace::ECategoryIndex*8) + (BTrace::EFastMutexWait << BTrace::ESubCategoryIndex*8)) );

#endif

	}

/***************************************************************************

 * IRQ Postamble

 * This routine is called after the IRQ has been dispatched

 * spsr_irq, r4-r11 are unmodified

 * spsr_irq,r0-r3,r12,return address are on the top of the IRQ stack

 ***************************************************************************/

extern "C" __NAKED__ void __ArmVectorIrq()

	{

	// FIQs enabled here but not IRQs

	asm("ldr r1, __TheScheduler ");

	asm("mrs r0, spsr ");					// check interrupted mode

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("add r12, sp, #32 ");				// r12=sp_irq+8 words

#else

	asm("add r12, sp, #24 ");				// r12=sp_irq+6 words

#endif

	asm("and r2, r0, #0x1f ");

	asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TScheduler,iKernCSLocked));	// r3=KernCSLocked

	asm("cmp r2, #0x10 ");					// check for mode_usr

	asm("cmpne r2, #0x13 ");				// or mode_svc

	asm("cmpeq r3, #0 ");					// and then check if kernel locked

	asm("bne IrqExit0 ");					// if wrong mode or locked, return immediately

	SET_INTS(r2, MODE_IRQ, INTS_ALL_OFF);	// disable FIQs before we check for reschedule

	asm("ldr r2, [r1, #%a0]" : : "i" _FOFF(TScheduler,iRescheduleNeededFlag));	// r2=DfcPendingFlag/RescheduleNeededFlag

	asm("add r3, r3, #1 ");

	SET_MODE_1(lr, MODE_SVC, INTS_ALL_ON);

	asm("cmp r2, #0 ");						// check if reschedule needed

	asm("beq IrqExit0 ");					// if not, return immediately

	asm("str r3, [r1, #%a0]" : : "i" _FOFF(TScheduler,iKernCSLocked));	// lock the kernel

	SET_MODE_2(lr, MODE_SVC, INTS_ALL_ON);	// mode_svc, interrupts back on

	asm("ldmdb r12!, {r1-r3} ");			// move saved registers (r0-r3,r12,pc) over to mode_svc stack

	asm("stmfd sp!, {r1-r3} ");

	asm("ldmdb r12!, {r1-r3} ");

	asm("stmfd sp!, {r1-r3} ");

	asm("stmfd sp!, {r0,lr} ");				// store lr_svc and interrupted cpsr on current mode_svc stack

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("ldmdb r12, {r1-r2} ");

	asm("stmfd sp!, {r1-r2} ");				// move user guard over to mode_svc stack

#endif

	SET_MODE_1(r2, MODE_SVC, INTS_ALL_ON);

	SET_MODE(lr, MODE_IRQ, INTS_IRQ_OFF);	// mode_irq, IRQs off

	asm("add sp, r12, #24 ");				// restore mode_irq stack balance

	SET_MODE_2(r2, MODE_SVC, INTS_ALL_ON);	// back to mode_svc, IRQs on

	// reschedule - this also switches context if necessary

	// enter this function in mode_svc, interrupts on, kernel locked

	// exit this function in mode_svc, all interrupts off, kernel unlocked

	asm("irq_do_resched: ");

	asm("bl  " CSM_ZN10TScheduler10RescheduleEv);

	asm(".global irq_resched_return ");

	asm("irq_resched_return: ");

	SET_MODE(r2, MODE_SVC, INTS_ALL_OFF);	// all interrupts off

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("ldr r1, [sp, #8] "	);				// get interrupted cpsr, don't unbalance stack

#else

	asm("ldr r1, [sp] "	);					// get interrupted cpsr, don't unbalance stack

#endif

#ifdef __CHECK_LOCK_STATE__

	asm("mov r2, r12 ");

	asm("tst r1, #0x0f ");

	asm("bleq  " CSM_Z14CheckLockStatev);

	asm("mov r12, r2 ");

#endif

	asm("tst r1, #0x0f ");

	asm("mov r3, #%a0 " : : "i" (NThread::EContextUserIntrCallback));

	asm("bleq callUserModeCallbacks ");		// call user-mode callbacks		

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("ldr r1, [sp], #8 ");

	USER_MEMORY_GUARD_RESTORE(r1,lr);

#endif

	asm("ldmfd sp!, {r1, lr} ");			// restore lr_svc

	asm("add sp, sp, #24 ");				// restore mode_svc stack balance

	asm("mov r12, sp ");					// r12=address of remaining saved registers

	SET_MODE(r2, MODE_IRQ, INTS_ALL_OFF);	// back into mode_irq, all interrupts off

	asm("msr spsr, r1 ");					// interrupted cpsr into spsr_irq

	ERRATUM_353494_MODE_CHANGE(,r12);

	asm("ldmdb r12, {r0-r3,r12,pc}^ ");		// return from interrupt

	asm("IrqExit0: ");

#ifdef __CHECK_LOCK_STATE__

	asm("tst r0, #0x0f ");

	asm("bleq  " CSM_Z14CheckLockStatev);

#endif

	asm("IrqExit1: ");						// entry point for __ArmVectorIrqPostambleNoResched()

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("ldr lr, [sp], #8 ");

	USER_MEMORY_GUARD_RESTORE(lr,r12);

#endif

#ifdef BTRACE_CPU_USAGE

	asm("ldrb r2, [r1,#%a0]" : : "i" _FOFF(TScheduler,iCpuUsageFilter));

	asm("mov r0, #%a0" : : "i" ((TInt)4 ) );

	asm("add r0, r0, #%a0" : : "i" ((TInt)(BTrace::ECpuUsage<<BTrace::ECategoryIndex*8)+(BTrace::EIrqEnd<<BTrace::ESubCategoryIndex*8)) );

	asm("cmp r2, #0");

	asm("movne lr, pc");

	asm("ldrne pc, [r1,#%a0]" : : "i" _FOFF(TScheduler,iBTraceHandler));

#endif

	ERRATUM_353494_MODE_CHANGE(,r12);

	asm("ldmfd sp!, {r0-r3,r12,pc}^ ");		// return from interrupt

	}

/***************************************************************************

 * IRQ Postamble which will not reschedule (can be returned to by co-resident OS).

 * This routine is called after the IRQ has been dispatched

 * spsr_irq, r4-r11 are unmodified

 * spsr_irq,r0-r3,r12,return address are on the top of the IRQ stack

 ***************************************************************************/

extern "C" EXPORT_C __NAKED__ void __ArmVectorIrqPostambleNoResched()

	{

	// FIQs enabled here but not IRQs

	asm("ldr r1, __TheScheduler ");

	asm("b IrqExit1 ");

	}

/***************************************************************************

 * FIQ Postamble

 * This routine is called after the FIQ has been dispatched

 * spsr_fiq, r0-r3 are unmodified

 * Return address is on the top of the FIQ stack

 ***************************************************************************/

extern "C" __NAKED__ void __ArmVectorFiq()

	{

#ifdef __FAULT_ON_FIQ__

	asm(".word 0xe7f10f10 ");

#endif

	// IRQs and FIQs disabled here

	// r0-r7 are unaltered from when FIQ occurred

	asm("ldr r9, __TheScheduler ");

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("ldr r12, [sp], #4 ");

#endif

	asm("mrs r8, spsr ");					// check interrupted mode

	asm("and r10, r8, #0x1f ");

	asm("cmp r10, #0x10 ");					// check for mode_usr

	asm("ldr r11, [r9, #%a0]" : : "i" _FOFF(TScheduler,iKernCSLocked));

	asm("cmpne r10, #0x13 ");				// or mode_svc

	asm("ldreq r10, [r9, #%a0]" : : "i" _FOFF(TScheduler,iRescheduleNeededFlag));

	asm("cmpeq r11, #0 ");					// and check if kernel locked

	asm("bne FiqExit0 ");					// if wrong mode or kernel locked, return immediately

	asm("cmp r10, #0 ");					// check if reschedule needed

	asm("beq FiqExit0 ");					// if not, return from interrupt

	// we interrupted mode_usr or mode_svc, kernel unlocked, reschedule needed

	asm("add r11, r11, #1 ");

	asm("str r11, [r9, #%a0]" : : "i" _FOFF(TScheduler,iKernCSLocked));	// lock the kernel

	asm("stmfd sp!, {r1-r3} ");				// save interrupted r1-r3 on FIQ stack

	asm("mov r1, r8 ");						// r1=interrupted cpsr

	asm("mov r3, sp ");						// r3 points to saved registers

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("mov r2, r12 ");					// saved DACR into R2

#endif

	SET_MODE(lr, MODE_SVC, INTS_ALL_ON);	// switch to mode_svc, IRQs and FIQs back on

#ifdef __USER_MEMORY_GUARDS_ENABLED__

	asm("str r2, [sp, #-40]! ");			// save DACR and leave room for spare, cpsr, lr_svc, r0-r3, r12, pc

	asm("ldr r2, [r3, #12] ");				// r2=return address

	asm("str r12, [sp, #32] ");				// save r12 on mode_svc stack

	asm("str r2, [sp, #36] ");				// save return address on mode_svc stack

	asm("add r12, sp, #8 ");

#else

	asm("ldr r2, [r3, #12] ");				// r2=return address

	asm("sub sp, sp, #32 ");				// make room for saved registers on mode_svc stack

	asm("str r12, [sp, #24] ");				// save r12 on mode_svc stack

	asm("str r2, [sp, #28] ");				// save return address on mode_svc stack

	asm("mov r12, sp ");

#endif

	asm("stmia r12!, {r1,lr} ");			// save interrupted cpsr and lr_svc

	asm("ldmia r3, {r1,r2,lr} ");			// retrieve original r1-r3 from mode_fiq stack

	asm("stmia r12, {r0-r2,lr} ");			// save original r0-r3 - saved register order is now cpsr,lr_svc,r0-r3,r12,pc

	SET_MODE_1(r2, MODE_SVC, INTS_ALL_ON);

	SET_MODE(lr, MODE_FIQ, INTS_ALL_OFF);	// mode_fiq, IRQs and FIQs off

	asm("add sp, r3, #16 ");				// restore mode_fiq stack balance

	SET_MODE_2(r2, MODE_SVC, INTS_ALL_ON);	// back to mode_svc, IRQs on

	asm("adr lr, irq_resched_return ");

	asm("b  " CSM_ZN10TScheduler10RescheduleEv);		// do reschedule and return to irq_resched_return

	asm("FiqExit0:");						// also entry point for __ArmVectorFiqPostambleNoResched()

	USER_MEMORY_GUARD_RESTORE(r12,lr);

#ifndef BTRACE_CPU_USAGE

	ERRATUM_353494_MODE_CHANGE(,r11);