diff -r 000000000000 -r a41df078684a kernel/eka/nkernsmp/arm/ncutilf.cia --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/kernel/eka/nkernsmp/arm/ncutilf.cia Mon Oct 19 15:55:17 2009 +0100 @@ -0,0 +1,1607 @@ +// 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\nkernsmp\arm\ncutilf.cia +// +// + +#include +#include +#include +#include + + + +__NAKED__ void Arm::GetUserSpAndLr(TAny*) + { + asm("stmia r0, {r13, r14}^ "); + asm("mov r0, r0"); // NOP needed between stm^ and banked register access + __JUMP(, lr); + } + +__NAKED__ void Arm::SetUserSpAndLr(TAny*) + { + asm("ldmia r0, {r13, r14}^ "); + asm("mov r0, r0"); // NOP needed between ldm^ and banked register access + __JUMP(, lr); + } + +__NAKED__ TUint32 Arm::Dacr() + { + asm("mrc p15, 0, r0, c3, c0, 0 "); + __JUMP(, lr); + } + +__NAKED__ void Arm::SetDacr(TUint32) + { + asm("mcr p15, 0, r0, c3, c0, 0 "); + __INST_SYNC_BARRIER_Z__(r1); + __JUMP(, lr); + } + +__NAKED__ TUint32 Arm::ModifyDacr(TUint32, TUint32) + { + asm("mrc p15, 0, r2, c3, c0, 0 "); + asm("bic r2, r2, r0 "); + asm("orr r2, r2, r1 "); + asm("mcr p15, 0, r2, c3, c0, 0 "); + __INST_SYNC_BARRIER_Z__(r3); + asm("mov r0, r2 "); + __JUMP(, lr); + } + +__NAKED__ void Arm::SetCar(TUint32) + { + SET_CAR(, r0); + __JUMP(, lr); + } + + + +/** Get the CPU's coprocessor access register value + +@return The value of the CAR, 0 if CPU doesn't have CAR + +@publishedPartner +@released + */ +EXPORT_C __NAKED__ TUint32 Arm::Car() + { + GET_CAR(, r0); + __JUMP(, lr); + } + + + +/** Modify the CPU's coprocessor access register value + Does nothing if CPU does not have CAR. + +@param aClearMask Mask of bits to clear (1 = clear this bit) +@param aSetMask Mask of bits to set (1 = set this bit) +@return The original value of the CAR, 0 if CPU doesn't have CAR + +@publishedPartner +@released + */ +EXPORT_C __NAKED__ TUint32 Arm::ModifyCar(TUint32 /*aClearMask*/, TUint32 /*aSetMask*/) + { + GET_CAR(, r2); + asm("bic r0, r2, r0 "); + asm("orr r0, r0, r1 "); + SET_CAR(, r0); + asm("mov r0, r2 "); + __JUMP(, lr); + } + + +#ifdef __CPU_HAS_VFP +__NAKED__ void Arm::SetFpExc(TUint32) + { +#if defined(__CPU_ARM1136__) && !defined(__CPU_ARM1136_ERRATUM_351912_FIXED) +// If we are about to enable VFP, disable dynamic branch prediction +// If we are about to disable VFP, enable dynamic branch prediction if return stack prediction is enabled + asm("mrs r3, cpsr "); + __ASM_CLI(); + asm("mrc p15, 0, r1, c1, c0, 1 "); + asm("tst r0, #%a0" : : "i" ((TInt)VFP_FPEXC_EN) ); + asm("bic r1, r1, #2 "); // clear DB bit (disable dynamic prediction) + asm("and r2, r1, #1 "); // r2 bit 0 = RS bit (1 if return stack enabled) + asm("orreq r1, r1, r2, lsl #1 "); // if VFP is being disabled set DB = RS + asm("mcr p15, 0, r1, c1, c0, 1 "); + asm("mcr p15, 0, r2, c7, c5, 6 "); // flush BTAC + VFP_FMXR(, VFP_XREG_FPEXC,0); + __INST_SYNC_BARRIER_Z__(r12); + asm("msr cpsr, r3 "); + __JUMP(, lr); +#else + VFP_FMXR(, VFP_XREG_FPEXC,0); + __JUMP(, lr); +#endif + } +#endif + + + +/** Get the value of the VFP FPEXC register + +@return The value of FPEXC, 0 if there is no VFP + +@publishedPartner +@released + */ +EXPORT_C __NAKED__ TUint32 Arm::FpExc() + { +#ifdef __CPU_HAS_VFP + VFP_FMRX(, 0,VFP_XREG_FPEXC); +#else + asm("mov r0, #0 "); +#endif + __JUMP(, lr); + } + + + +/** Modify the VFP FPEXC register + Does nothing if there is no VFP + +@param aClearMask Mask of bits to clear (1 = clear this bit) +@param aSetMask Mask of bits to set (1 = set this bit) +@return The original value of FPEXC, 0 if no VFP present + +@publishedPartner +@released + */ +EXPORT_C __NAKED__ TUint32 Arm::ModifyFpExc(TUint32 /*aClearMask*/, TUint32 /*aSetMask*/) + { +#ifdef __CPU_HAS_VFP + VFP_FMRX(, 12,VFP_XREG_FPEXC); + asm("bic r0, r12, r0 "); + asm("orr r0, r0, r1 "); + +#if defined(__CPU_ARM1136__) && !defined(__CPU_ARM1136_ERRATUM_351912_FIXED) +// If we are about to enable VFP, disable dynamic branch prediction +// If we are about to disable VFP, enable dynamic branch prediction if return stack prediction is enabled + asm("mrs r3, cpsr "); + __ASM_CLI(); + asm("mrc p15, 0, r1, c1, c0, 1 "); + asm("tst r0, #%a0" : : "i" ((TInt)VFP_FPEXC_EN) ); + asm("bic r1, r1, #2 "); // clear DB bit (disable dynamic prediction) + asm("and r2, r1, #1 "); // r2 bit 0 = RS bit (1 if return stack enabled) + asm("orreq r1, r1, r2, lsl #1 "); // if VFP is being disabled set DB = RS + asm("mcr p15, 0, r1, c1, c0, 1 "); + asm("mcr p15, 0, r2, c7, c5, 6 "); // flush BTAC + VFP_FMXR(, VFP_XREG_FPEXC,0); + __INST_SYNC_BARRIER_Z__(r12); + asm("msr cpsr, r3 "); +#else + VFP_FMXR(, VFP_XREG_FPEXC,0); +#endif // erratum 351912 + + asm("mov r0, r12 "); +#else // no vfp + asm("mov r0, #0 "); +#endif + __JUMP(, lr); + } + +/** Get the value of the VFP FPSCR register + +@return The value of FPSCR, 0 if there is no VFP + +@publishedPartner +@released + */ +EXPORT_C __NAKED__ TUint32 Arm::FpScr() + { +#ifdef __CPU_HAS_VFP + VFP_FMRX(, 0,VFP_XREG_FPSCR); +#else + asm("mov r0, #0 "); +#endif + __JUMP(, lr); + } + + + +/** Modify the VFP FPSCR register + Does nothing if there is no VFP + +@param aClearMask Mask of bits to clear (1 = clear this bit) +@param aSetMask Mask of bits to set (1 = set this bit) +@return The original value of FPSCR, 0 if no VFP present + +@publishedPartner +@released + */ +EXPORT_C __NAKED__ TUint32 Arm::ModifyFpScr(TUint32 /*aClearMask*/, TUint32 /*aSetMask*/) + { +#ifdef __CPU_HAS_VFP + VFP_FMRX(, 2,VFP_XREG_FPSCR); + asm("bic r0, r2, r0 "); + asm("orr r0, r0, r1 "); + VFP_FMXR(, VFP_XREG_FPSCR,0); + asm("mov r0, r2 "); +#else + asm("mov r0, #0 "); +#endif + __JUMP(, lr); + } + + +/** Detect whether NEON is present + +@return ETrue if present, EFalse if not + +@internalTechnology +@released + */ +#if defined(__CPU_HAS_VFP) && defined(__VFP_V3) +__NAKED__ TBool Arm::NeonPresent() + { + asm("mov r0, #0 "); // Not present + VFP_FMRX(, 1,VFP_XREG_FPEXC); // Save VFP state + asm("orr r2, r1, #%a0" : : "i" ((TInt)VFP_FPEXC_EN)); + VFP_FMXR(, VFP_XREG_FPEXC,1); // Enable VFP + + VFP_FMRX(, 2,VFP_XREG_MVFR0); // Read MVFR0 + asm("tst r2, #%a0" : : "i" ((TInt)VFP_MVFR0_ASIMD32)); // Check to see if all 32 Advanced SIMD registers are present + asm("beq 0f "); // Skip ahead if not + GET_CAR(, r2); + asm("tst r2, #%a0" : : "i" ((TInt)VFP_CPACR_ASEDIS)); // Check to see if ASIMD is disabled + asm("bne 0f "); // Skip ahead if so + asm("tst r2, #%a0" : : "i" ((TInt)VFP_CPACR_D32DIS)); // Check to see if the upper 16 registers are disabled + asm("moveq r0, #1" ); // If not then eport NEON present + + asm("0: "); + VFP_FMXR(,VFP_XREG_FPEXC,1); // Restore VFP state + __JUMP(, lr); + } +#endif + + +#ifdef __CPU_HAS_MMU +__NAKED__ TBool Arm::MmuActive() + { + asm("mrc p15, 0, r0, c1, c0, 0 "); + asm("and r0, r0, #1 "); + __JUMP(, lr); + } + +// Returns the content of Translate Table Base Register 0. +// To get physical address of the level 1 table, on some platforms this must be orred with 0xffff8000 (to get rid of table walk cache attributes) +__NAKED__ TUint32 Arm::MmuTTBR0() + { + asm("mrc p15, 0, r0, c2, c0, 0 "); + __JUMP(, lr); + } +#endif + + + +/** Get the current value of the system timestamp + +@publishedPartner +@prototype +*/ +EXPORT_C __NAKED__ TUint64 NKern::Timestamp() + { + asm("ldr r3, __TheScheduler "); + asm("mrs r12, cpsr "); // r12 = saved interrupt mask + asm("ldr r2, [r3, #%a0]" : : "i" _FOFF(TScheduler,i_LocalTimerAddr)); // r2 points to local timer + __ASM_CLI(); // disable all interrupts + GET_RWNO_TID(,r3); // r3 -> TSubScheduler + asm("ldr r1, [r2, #%a0]" : : "i" _FOFF(ArmLocalTimer,iTimerCount)); // r1 = current timer counter + asm("ldr r0, [r3, #%a0]" : : "i" _FOFF(TSubScheduler,i_LastTimerSet)); // r0 = last value written to timer counter + asm("ldr r2, [r3, #%a0]" : : "i" _FOFF(TSubScheduler,i_TimerMultI)); // r2 = scaling factor + asm("sub r0, r0, r1 "); // elapsed timer ticks since last timestamp sync + asm("umull r1, r2, r0, r2 "); // r2:r1 = elapsed ticks * scaling factor + asm("ldr r0, [r3, #%a0]!" : : "i" _FOFF(TSubScheduler,iLastTimestamp64)); // r0 = last timestamp sync point, low word + asm("ldr r3, [r3, #4] "); // r3 = last timestamp sync point, high word + asm("adds r1, r1, #0x00800000 "); // add 2^23 (rounding) + asm("adcs r2, r2, #0 "); + asm("mov r1, r1, lsr #24 "); // divide by 2^24 + asm("orr r1, r1, r2, lsl #8 "); // r1 = elapsed time since last timestamp sync + asm("msr cpsr, r12 "); // restore interrupts + asm("adds r0, r0, r1 "); // r1:r0 = last timestamp sync point + elapsed time since last timestamp sync + asm("adcs r1, r3, #0 "); + __JUMP(,lr); + asm("__TheScheduler: "); + asm(".word %a0" : : "i" ((TInt)&TheScheduler)); + } + + +extern "C" __NAKED__ TLinAddr get_sp_svc() + { + asm("mrs r1, cpsr "); + __ASM_CLI_MODE(MODE_SVC); + asm("mov r0, sp "); + asm("msr cpsr, r1 "); + __JUMP(, lr); + } + +extern "C" __NAKED__ TLinAddr get_lr_svc() + { + asm("mrs r1, cpsr "); + __ASM_CLI_MODE(MODE_SVC); + asm("mov r0, lr "); + asm("msr cpsr, r1 "); + __JUMP(, lr); + } + + +/** Get the return address from an ISR + +Call only from an ISR + +@internalTechnology +*/ +EXPORT_C __NAKED__ TLinAddr Arm::IrqReturnAddress() + { + asm("mrs r1, cpsr "); + __ASM_CLI(); + asm("and r0, r1, #0x1f "); + asm("cmp r0, #0x11 "); // mode_fiq ? + asm("beq 1f "); + __ASM_CLI_MODE(MODE_SVC); + asm("ldr r0, [sp, #%a0]" : : "i" _FOFF(SThreadExcStack,iR15)); + asm("msr cpsr, r1 "); + __JUMP(, lr); + + asm("1: "); + GET_RWNO_TID(,r3); + asm("ldr r2, [r3, #%a0]" : : "i" _FOFF(TSubScheduler,i_FiqStackTop)); // if so, r2->top of FIQ stack + asm("ldr r0, [r2, #-4] "); // get return address + asm("msr cpsr, r1 "); + __JUMP(, lr); + } + +#if defined(__INCLUDE_SPIN_LOCK_CHECKS__) +#define __ASM_CALL(func) \ + asm("str lr, [sp, #-4]! "); \ + asm("bl " CSM_CFUNC(func)); \ + asm("ldr lr, [sp], #4 "); + +#define SPIN_LOCK_ENTRY_CHECK() __ASM_CALL(spin_lock_entry_check) +#define SPIN_LOCK_MARK_ACQ() __ASM_CALL(spin_lock_mark_acq) +#define SPIN_UNLOCK_ENTRY_CHECK() __ASM_CALL(spin_unlock_entry_check) + +#define RWSPIN_RLOCK_ENTRY_CHECK() __ASM_CALL(rwspin_rlock_entry_check) +#define RWSPIN_RLOCK_MARK_ACQ() __ASM_CALL(rwspin_rlock_mark_acq) +#define RWSPIN_RUNLOCK_ENTRY_CHECK() __ASM_CALL(rwspin_runlock_entry_check) + +#define RWSPIN_WLOCK_ENTRY_CHECK() __ASM_CALL(rwspin_wlock_entry_check) +#define RWSPIN_WLOCK_MARK_ACQ() __ASM_CALL(rwspin_wlock_mark_acq) +#define RWSPIN_WUNLOCK_ENTRY_CHECK() __ASM_CALL(rwspin_wunlock_entry_check) + +#else +#define SPIN_LOCK_ENTRY_CHECK() +#define SPIN_LOCK_MARK_ACQ() +#define SPIN_UNLOCK_ENTRY_CHECK() + +#define RWSPIN_RLOCK_ENTRY_CHECK() +#define RWSPIN_RLOCK_MARK_ACQ() +#define RWSPIN_RUNLOCK_ENTRY_CHECK() + +#define RWSPIN_WLOCK_ENTRY_CHECK() +#define RWSPIN_WLOCK_MARK_ACQ() +#define RWSPIN_WUNLOCK_ENTRY_CHECK() + +#endif + + +/****************************************************************************** + * Spin locks + * + * [this+0] in count (byte) + * [this+1] out count (byte) + * [this+6] order (byte) + * [this+7] holding CPU (byte) + ******************************************************************************/ + +#if defined(__INCLUDE_SPIN_LOCK_CHECKS__) +extern "C" __NAKED__ void spin_lock_entry_check() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1,r2,r3,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq slec_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldrh r2, [r0, #6] "); /* R2[8:15]=holding CPU, R2[0:7]=order */ + asm("tst r2, #0xE0 "); + asm("bne slec_preemption "); /* This lock requires preemption to be disabled */ + + /* check interrupts disabled, if interrupts/preemption is not disabled + there is a risk of same core deadlock occuring, hence this check and + run-time assert to ensure code stays safe */ + asm("and r3, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("cmp r3, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* Check interrupts masked */ + asm("beq slec_1 "); /* Yes - OK */ + __ASM_CRASH(); /* No - die */ + + asm("slec_preemption: "); + asm("and r3, r2, #0xFF "); + asm("cmp r3, #0xFF "); /* check for EOrderNone */ + asm("beq slec_1 "); /* EOrderNone - don't check interrupts or preemption */ + asm("and r3, r12, #0x1F "); + asm("cmp r3, #0x13 "); /* Make sure we're in mode_svc */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iKernLockCount)); + asm("bne slec_preemption_die "); /* If not, die */ + asm("cmp r3, #0 "); + asm("bne slec_1 "); /* Preemption disabled - OK */ + asm("slec_preemption_die: "); + __ASM_CRASH(); /* Preemption enabled - die */ + + asm("slec_1: "); + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuNum)); + asm("cmp r3, r2, lsr #8 "); /* Test if held by current CPU */ + asm("bne slec_2 "); /* Not already held by this CPU - OK */ + __ASM_CRASH(); /* Already held by this CPU - die */ + + asm("slec_2: "); + asm("ldr r3, [r1, #%a0]!" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("ldr r1, [r1, #4] "); /* r3=low word of iSpinLockOrderCheck, r1=high word */ + asm("cmp r3, #0 "); + asm("addeq r2, r2, #0x20000000 "); /* if low word zero, add 32 to LS1 index ... */ + asm("moveq r3, r1 "); /* ... and r3=high word ... */ + asm("subs r1, r3, #1 "); /* R1 = R3 with all bits up to and including LS1 flipped */ + asm("beq slec_ok "); /* If all bits zero, no locks held so OK */ + asm("eor r3, r3, r1 "); /* Clear all bits above LS1 */ + CLZ(1,3); /* R1 = 31 - bit number of LS1 */ + asm("rsb r1, r1, #31 "); /* R1 = bit number of LS1 */ + asm("add r1, r1, r2, lsr #24 "); /* add 32 if we were looking at high word */ + asm("mov r2, r2, lsl #24 "); /* this lock's order value into R2 high byte */ + asm("cmp r1, r2, asr #24 "); /* compare current lowest order lock to sign-extended order value */ + asm("bgt slec_ok "); /* if this lock's order < current lowest, OK */ + __ASM_CRASH(); /* otherwise die */ + + asm("slec_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1,r2,r3,r12} "); + __JUMP(,lr); + } + +extern "C" __NAKED__ void spin_lock_mark_acq() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1,r2,r3,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq slma_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuNum)); + asm("ldrb r2, [r0, #6] "); /* R2 = lock order value */ + asm("add r1, r1, #%a0" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("strb r3, [r0, #7] "); /* set byte 7 to holding CPU number */ + asm("cmp r2, #0x40 "); + asm("bhs slma_ok "); /* if EOrderNone, done */ + asm("cmp r2, #0x20 "); + asm("addhs r1, r1, #4 "); + asm("and r2, r2, #0x1f "); + asm("mov r3, #1 "); + asm("mov r3, r3, lsl r2 "); /* r3 = bit to set */ + asm("ldr r2, [r1] "); + asm("orr r2, r2, r3 "); + asm("str r2, [r1] "); /* set bit in iSpinLockOrderCheck corresponding to lock order */ + + asm("slma_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1,r2,r3,r12} "); + __JUMP(,lr); + } + +extern "C" __NAKED__ void spin_unlock_entry_check() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1,r2,r3,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq suec_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldrh r2, [r0, #6] "); /* R2[8:15]=holding CPU, R2[0:7]=order */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuNum)); + asm("eor r2, r2, r3, lsl #8 "); /* R2[8:15]=holding CPU^current CPU, R2[0:7]=order */ + asm("tst r2, #0xE0 "); + asm("bne suec_preemption "); /* This lock requires preemption to be disabled */ + + /* check interrupts disabled */ + asm("and r3, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("cmp r3, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* Check interrupts masked */ + asm("beq suec_1 "); /* Yes - OK */ + __ASM_CRASH(); /* No - die */ + + asm("suec_preemption: "); + asm("and r3, r2, #0xFF "); + asm("cmp r3, #0xFF "); /* check for EOrderNone */ + asm("ldrne r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iKernLockCount)); + asm("beq suec_1 "); /* EOrderNone - don't check interrupts or preemption */ + asm("cmp r3, #0 "); + asm("bne suec_1 "); /* Preemption disabled - OK */ + __ASM_CRASH(); /* Preemption enabled - die */ + + asm("suec_1: "); + asm("tst r2, #0xFF00 "); /* Check if holding CPU ^ current CPU number == 0 */ + asm("beq suec_2 "); /* Held by this CPU - OK */ + __ASM_CRASH(); /* Not held by this CPU - die */ + + asm("suec_2: "); + asm("add r1, r1, #%a0" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("mov r3, #0xFF "); + asm("strb r3, [r0, #7] "); /* reset holding CPU */ + asm("cmp r2, #0x40 "); + asm("bhs suec_ok "); /* if EOrderNone, done */ + asm("cmp r2, #0x20 "); + asm("addhs r1, r1, #4 "); + asm("and r2, r2, #0x1F "); + asm("mov r3, #1 "); + asm("mov r3, r3, lsl r2 "); /* r3 = bit to clear */ + asm("ldr r2, [r1] "); + asm("tst r2, r3 "); /* test bit originally set */ + asm("bic r2, r2, r3 "); + asm("str r2, [r1] "); /* clear bit in iSpinLockOrderCheck corresponding to lock order */ + asm("bne suec_ok "); /* if originally set, OK */ + __ASM_CRASH(); /* if not, die - something must have got corrupted */ + + asm("suec_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1,r2,r3,r12} "); + __JUMP(,lr); + } +#endif + + +/****************************************************************************** + * Plain old spin lock + * + * Fundamental algorithm: + * lock() { old_in = in++; while(out!=old_in) __chill(); } + * unlock() { ++out; } + * + * [this+0] out count (byte) + * [this+1] in count (byte) + * + ******************************************************************************/ +__NAKED__ EXPORT_C void TSpinLock::LockIrq() + { + __ASM_CLI(); /* Disable interrupts */ + SPIN_LOCK_ENTRY_CHECK() + asm("1: "); + LDREXH(1,0); + asm("mov r2, r1, lsr #8 "); /* R2 = original in count */ + asm("add r1, r1, #0x100 "); + STREXH(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("and r1, r1, #0xFF "); /* R1 = out count */ + asm("3: "); + asm("cmp r2, r1 "); /* out = original in ? */ + asm("bne 2f "); /* no - must wait */ + SPIN_LOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldrb r1, [r0, #0] "); /* read out count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TSpinLock::UnlockIrq() + { + SPIN_UNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r1); /* Ensure accesses don't move outside locked section */ + asm("ldrb r2, [r0, #0] "); + asm("add r2, r2, #1 "); + asm("strb r2, [r0, #0] "); /* ++out */ + __DATA_SYNC_BARRIER__(r1); /* Ensure write to out completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + __ASM_STI(); /* Enable interrupts */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TSpinLock::FlashIrq() + { + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r12, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,i_GicCpuIfcAddr)); + asm("ldrh r1, [r0, #0] "); + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(GicCpuIfc,iHighestPending)); + asm("sub r1, r1, r1, lsr #8 "); /* r1 low byte = (out - in) mod 256 */ + asm("and r1, r1, #0xFF "); + asm("cmp r1, #0xFF "); /* if out - in = -1, no-one else waiting */ + asm("addeq r3, r3, #1 "); + asm("cmpeq r3, #1024 "); /* if no-one waiting for lock, check for pending interrupt */ + asm("bne 1f "); /* branch if someone else waiting */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN9TSpinLock9UnlockIrqEv); + asm("bl " CSM_ZN9TSpinLock7LockIrqEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +__NAKED__ EXPORT_C void TSpinLock::LockOnly() + { + SPIN_LOCK_ENTRY_CHECK() + asm("1: "); + LDREXH(1,0); + asm("mov r2, r1, lsr #8 "); /* R2 = original in count */ + asm("add r1, r1, #0x100 "); + STREXH(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("and r1, r1, #0xFF "); /* R1 = out count */ + asm("3: "); + asm("cmp r2, r1 "); /* out = original in ? */ + asm("bne 2f "); /* no - must wait */ + SPIN_LOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldrb r1, [r0, #0] "); /* read out count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TSpinLock::UnlockOnly() + { + SPIN_UNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r1); /* Ensure accesses don't move outside locked section */ + asm("ldrb r2, [r0, #0] "); + asm("add r2, r2, #1 "); + asm("strb r2, [r0, #0] "); /* ++out */ + __DATA_SYNC_BARRIER__(r1); /* Ensure write to out completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TSpinLock::FlashOnly() + { + asm("ldrh r1, [r0, #0] "); + asm("sub r1, r1, r1, lsr #8 "); /* r1 low byte = (out - in) mod 256 */ + asm("and r1, r1, #0xFF "); + asm("cmp r1, #0xFF "); /* if out - in = -1, no-one else waiting */ + asm("bne 1f "); /* branch if someone else waiting */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN9TSpinLock10UnlockOnlyEv); + asm("bl " CSM_ZN9TSpinLock8LockOnlyEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +__NAKED__ EXPORT_C TInt TSpinLock::LockIrqSave() + { + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + SPIN_LOCK_ENTRY_CHECK() + asm("1: "); + LDREXH(1,0); + asm("mov r2, r1, lsr #8 "); /* R2 = original in count */ + asm("add r1, r1, #0x100 "); + STREXH(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("and r1, r1, #0xFF "); /* R1 = out count */ + asm("3: "); + asm("cmp r2, r1 "); /* out = original in ? */ + asm("bne 2f "); /* no - must wait */ + SPIN_LOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + asm("and r0, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* return original CPSR I and F bits */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldrb r1, [r0, #0] "); /* read out count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TSpinLock::UnlockIrqRestore(TInt) + { + SPIN_UNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r3); /* Ensure accesses don't move outside locked section */ + asm("ldrb r2, [r0, #0] "); + asm("mrs r12, cpsr "); + asm("add r2, r2, #1 "); + asm("bic r12, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("strb r2, [r0, #0] "); /* ++out */ + __DATA_SYNC_BARRIER__(r3); /* Ensure write to out completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + asm("orr r1, r1, r12 "); + asm("msr cpsr, r1 "); /* restore interrupts */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TSpinLock::FlashIrqRestore(TInt) + { + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r12, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,i_GicCpuIfcAddr)); + asm("ldrh r2, [r0, #0] "); + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(GicCpuIfc,iHighestPending)); + asm("sub r2, r2, r2, lsr #8 "); /* r2 low byte = (out - in) mod 256 */ + asm("and r2, r2, #0xFF "); + asm("cmp r2, #0xFF "); /* if out - in = -1, no-one else waiting */ + asm("addeq r3, r3, #1 "); + asm("cmpeq r3, #1024 "); /* if no-one waiting for lock, check for pending interrupt */ + asm("bne 1f "); /* branch if someone else waiting */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN9TSpinLock16UnlockIrqRestoreEi); + asm("bl " CSM_ZN9TSpinLock7LockIrqEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +__NAKED__ EXPORT_C TBool TSpinLock::FlashPreempt() + { + asm("ldrh r2, [r0, #0] "); + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,iRescheduleNeededFlag)); + asm("sub r2, r2, r2, lsr #8 "); /* r2 low byte = (out - in) mod 256 */ + asm("and r2, r2, #0xFF "); + asm("cmp r2, #0xFF "); /* if out - in = -1, no-one else waiting */ + asm("cmpeq r3, #0 "); /* if no-one else waiting, check if reschedule or IDFCs pending */ + asm("bne 1f "); /* if so or someone else waiting, branch to release lock */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("stmfd sp!, {r0,lr} "); + asm("bl " CSM_ZN9TSpinLock10UnlockOnlyEv); + asm("bl " CSM_ZN5NKern15PreemptionPointEv); + asm("ldr r0, [sp], #4 "); + asm("bl " CSM_ZN9TSpinLock8LockOnlyEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +/****************************************************************************** + * Read/Write Spin lock + * + * Structure ( (in.r,in.w) , (out.r,out.w) ) + * Fundamental algorithm: + * lockr() { old_in = (in.r++,in.w); while(out.w!=old_in.w) __chill(); } + * unlockr() { ++out.r; } + * lockw() { old_in = (in.r,in.w++); while(out!=old_in) __chill(); } + * unlockw() { ++out.w; } + * + * [this+0] in.w + * [this+1] in.r + * [this+2] out.w + * [this+3] out.r + * [this+4] Bit mask of CPUs which hold read locks + * [this+6] order value + * [this+7] CPU number which holds write lock, 0xFF if none + * + ******************************************************************************/ + +#if defined(__INCLUDE_SPIN_LOCK_CHECKS__) +extern "C" __NAKED__ void rwspin_rlock_entry_check() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1,r2,r3,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq rwrlec_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldr r2, [r0, #4] "); /* R2[24:31]=wcpu, R2[16:23]=order, R2[0:7]=rcpu mask */ + asm("tst r2, #0x00E00000 "); + asm("bne rwrlec_preemption "); /* This lock requires preemption to be disabled */ + + /* check interrupts disabled */ + asm("and r3, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("cmp r3, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* Check interrupts masked */ + asm("beq rwrlec_1 "); /* Yes - OK */ + __ASM_CRASH(); /* No - die */ + + asm("rwrlec_preemption: "); + asm("and r3, r2, #0x00FF0000 "); + asm("cmp r3, #0x00FF0000 "); /* check for EOrderNone */ + asm("beq rwrlec_1 "); /* EOrderNone - don't check interrupts or preemption */ + asm("and r3, r12, #0x1F "); + asm("cmp r3, #0x13 "); /* Make sure we're in mode_svc */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iKernLockCount)); + asm("bne rwrlec_preemption_die "); /* If not, die */ + asm("cmp r3, #0 "); + asm("bne rwrlec_1 "); /* Preemption disabled - OK */ + asm("rwrlec_preemption_die: "); + __ASM_CRASH(); /* Preemption enabled - die */ + + asm("rwrlec_1: "); + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuNum)); + asm("eor r3, r2, r3, lsl #24 "); + asm("cmp r3, #0x01000000 "); /* Held by current CPU for write ? */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuMask)); + asm("bhs rwrlec_2 "); /* No - OK */ + __ASM_CRASH(); /* Already held by this CPU for write - die */ + + asm("rwrlec_2: "); + asm("tst r2, r3 "); /* Held by current CPU for read ? */ + asm("beq rwrlec_3 "); /* No - OK */ + __ASM_CRASH(); /* Already held by this CPU for read - die */ + + asm("rwrlec_3: "); + asm("ldr r3, [r1, #%a0]!" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("mov r2, r2, lsr #16 "); + asm("and r2, r2, #0xFF "); /* r2 = lock order */ + asm("ldr r1, [r1, #4] "); /* r3=low word of iSpinLockOrderCheck, r1=high word */ + asm("cmp r3, #0 "); + asm("addeq r2, r2, #0x20000000 "); /* if low word zero, add 32 to LS1 index ... */ + asm("moveq r3, r1 "); /* ... and r3=high word ... */ + asm("subs r1, r3, #1 "); /* R1 = R3 with all bits up to and including LS1 flipped */ + asm("beq rwrlec_ok "); /* If all bits zero, no locks held so OK */ + asm("eor r3, r3, r1 "); /* Clear all bits above LS1 */ + CLZ(1,3); /* R1 = 31 - bit number of LS1 */ + asm("rsb r1, r1, #31 "); /* R1 = bit number of LS1 */ + asm("add r1, r1, r2, lsr #24 "); /* add 32 if we were looking at high word */ + asm("mov r2, r2, lsl #24 "); /* this lock's order value into R2 high byte */ + asm("cmp r1, r2, asr #24 "); /* compare current lowest order lock to sign-extended order value */ + asm("bgt rwrlec_ok "); /* if this lock's order < current lowest, OK */ + __ASM_CRASH(); /* otherwise die */ + + asm("rwrlec_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1,r2,r3,r12} "); + __JUMP(,lr); + } + +extern "C" __NAKED__ void rwspin_rlock_mark_acq() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1-r4,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq rwrlma_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuMask)); + asm("add r0, r0, #4 "); + asm("1: "); + LDREXB(2,0); /* rcpu mask */ + asm("orr r2, r2, r3 "); /* set bit corresponding to current CPU */ + STREXB(4,2,0); + asm("cmp r4, #0 "); + asm("bne 1b "); + asm("ldrb r2, [r0, #2] "); /* R2 = lock order value */ + asm("sub r0, r0, #4 "); + asm("add r1, r1, #%a0" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("cmp r2, #0x40 "); + asm("bhs rwrlma_ok "); /* if EOrderNone, done */ + asm("cmp r2, #0x20 "); + asm("addhs r1, r1, #4 "); + asm("and r2, r2, #0x1f "); + asm("mov r3, #1 "); + asm("mov r3, r3, lsl r2 "); /* r3 = bit to set */ + asm("ldr r2, [r1] "); + asm("orr r2, r2, r3 "); + asm("str r2, [r1] "); /* set bit in iSpinLockOrderCheck corresponding to lock order */ + + asm("rwrlma_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1-r4,r12} "); + __JUMP(,lr); + } + +extern "C" __NAKED__ void rwspin_runlock_entry_check() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1-r4,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq rwruec_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldr r2, [r0, #4] "); /* R2[24:31]=wcpu, R2[16:23]=order, R2[0:7]=rcpu mask */ + asm("tst r2, #0x00E00000 "); + asm("bne rwruec_preemption "); /* This lock requires preemption to be disabled */ + + /* check interrupts disabled */ + asm("and r3, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("cmp r3, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* Check interrupts masked */ + asm("beq rwruec_1 "); /* Yes - OK */ + __ASM_CRASH(); /* No - die */ + + asm("rwruec_preemption: "); + asm("and r3, r2, #0x00FF0000 "); + asm("cmp r3, #0x00FF0000 "); /* check for EOrderNone */ + asm("ldrne r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iKernLockCount)); + asm("beq rwruec_1 "); /* EOrderNone - don't check interrupts or preemption */ + asm("cmp r3, #0 "); + asm("bne rwruec_1 "); /* Preemption disabled - OK */ + __ASM_CRASH(); /* Preemption enabled - die */ + + asm("rwruec_1: "); + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuMask)); + asm("tst r2, r3 "); /* Check if current CPU holds read lock */ + asm("bne rwruec_2 "); /* Read lock held by this CPU - OK */ + __ASM_CRASH(); /* Not held by this CPU - die */ + + asm("rwruec_2: "); + asm("add r0, r0, #4 "); + asm("1: "); + LDREX(2,0); /* rcpu mask */ + asm("bic r2, r2, r3 "); /* clear bit corresponding to current CPU */ + STREX(4,2,0); + asm("cmp r4, #0 "); + asm("bne 1b "); + asm("sub r0, r0, #4 "); + asm("add r1, r1, #%a0" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("tst r2, #0x00C00000 "); + asm("bne rwruec_ok "); /* if EOrderNone, done */ + asm("tst r2, #0x00200000 "); + asm("addne r1, r1, #4 "); + asm("mov r2, r2, lsr #16 "); + asm("and r2, r2, #0x1F "); + asm("mov r3, #1 "); + asm("mov r3, r3, lsl r2 "); /* r3 = bit to clear */ + asm("ldr r2, [r1] "); + asm("tst r2, r3 "); /* test bit originally set */ + asm("bic r2, r2, r3 "); + asm("str r2, [r1] "); /* clear bit in iSpinLockOrderCheck corresponding to lock order */ + asm("bne rwruec_ok "); /* if originally set, OK */ + __ASM_CRASH(); /* if not, die - something must have got corrupted */ + + asm("rwruec_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1-r4,r12} "); + __JUMP(,lr); + } + + +extern "C" __NAKED__ void rwspin_wlock_entry_check() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1,r2,r3,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq rwwlec_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldr r2, [r0, #4] "); /* R2[24:31]=wcpu, R2[16:23]=order, R2[0:7]=rcpu mask */ + asm("tst r2, #0x00E00000 "); + asm("bne rwwlec_preemption "); /* This lock requires preemption to be disabled */ + + /* check interrupts disabled */ + asm("and r3, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("cmp r3, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* Check interrupts masked */ + asm("beq rwwlec_1 "); /* Yes - OK */ + __ASM_CRASH(); /* No - die */ + + asm("rwwlec_preemption: "); + asm("and r3, r2, #0x00FF0000 "); + asm("cmp r3, #0x00FF0000 "); /* check for EOrderNone */ + asm("beq rwwlec_1 "); /* EOrderNone - don't check interrupts or preemption */ + asm("and r3, r12, #0x1F "); + asm("cmp r3, #0x13 "); /* Make sure we're in mode_svc */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iKernLockCount)); + asm("bne rwwlec_preemption_die "); /* If not, die */ + asm("cmp r3, #0 "); + asm("bne rwwlec_1 "); /* Preemption disabled - OK */ + asm("rwwlec_preemption_die: "); + __ASM_CRASH(); /* Preemption enabled - die */ + + asm("rwwlec_1: "); + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuMask)); + asm("tst r2, r3 "); /* Test if held by current CPU for read */ + asm("beq rwwlec_2 "); /* No - OK */ + __ASM_CRASH(); /* Yes - die */ + + asm("rwwlec_2: "); + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuNum)); + asm("cmp r3, r2, lsr #24 "); /* Test if held by current CPU for write */ + asm("bne rwwlec_3 "); /* No - OK */ + __ASM_CRASH(); /* Yes - die */ + + asm("rwwlec_3: "); + asm("ldr r3, [r1, #%a0]!" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("mov r2, r2, lsr #16 "); + asm("and r2, r2, #0xFF "); /* r2 = lock order */ + asm("ldr r1, [r1, #4] "); /* r3=low word of iSpinLockOrderCheck, r1=high word */ + asm("cmp r3, #0 "); + asm("addeq r2, r2, #0x20000000 "); /* if low word zero, add 32 to LS1 index ... */ + asm("moveq r3, r1 "); /* ... and r3=high word ... */ + asm("subs r1, r3, #1 "); /* R1 = R3 with all bits up to and including LS1 flipped */ + asm("beq rwwlec_ok "); /* If all bits zero, no locks held so OK */ + asm("eor r3, r3, r1 "); /* Clear all bits above LS1 */ + CLZ(1,3); /* R1 = 31 - bit number of LS1 */ + asm("rsb r1, r1, #31 "); /* R1 = bit number of LS1 */ + asm("add r1, r1, r2, lsr #24 "); /* add 32 if we were looking at high word */ + asm("mov r2, r2, lsl #24 "); /* this lock's order value into R2 high byte */ + asm("cmp r1, r2, asr #24 "); /* compare current lowest order lock to sign-extended order value */ + asm("bgt rwwlec_ok "); /* if this lock's order < current lowest, OK */ + __ASM_CRASH(); /* otherwise die */ + + asm("rwwlec_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1,r2,r3,r12} "); + __JUMP(,lr); + } + +extern "C" __NAKED__ void rwspin_wlock_mark_acq() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1,r2,r3,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq rwwlma_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuNum)); + asm("ldrb r2, [r0, #6] "); /* R2 = lock order value */ + asm("add r1, r1, #%a0" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("strb r3, [r0, #7] "); /* set byte 7 to holding CPU number */ + asm("cmp r2, #0x40 "); + asm("bhs rwwlma_ok "); /* if EOrderNone, done */ + asm("cmp r2, #0x20 "); + asm("addhs r1, r1, #4 "); + asm("and r2, r2, #0x1f "); + asm("mov r3, #1 "); + asm("mov r3, r3, lsl r2 "); /* r3 = bit to set */ + asm("ldr r2, [r1] "); + asm("orr r2, r2, r3 "); + asm("str r2, [r1] "); /* set bit in iSpinLockOrderCheck corresponding to lock order */ + + asm("rwwlma_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1,r2,r3,r12} "); + __JUMP(,lr); + } + +extern "C" __NAKED__ void rwspin_wunlock_entry_check() + { + /* R0 points to lock */ + asm("stmfd sp!, {r1,r2,r3,r12} "); + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + GET_RWNO_TID(, r1); /* R1->SubScheduler */ + asm("cmp r1, #0 "); + asm("beq rwwuec_ok "); /* Skip checks if subscheduler not yet initialised */ + asm("ldrh r2, [r0, #6] "); /* R2[8:15]=holding CPU, R2[0:7]=order */ + asm("ldr r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iCpuNum)); + asm("eor r2, r2, r3, lsl #8 "); /* R2[8:15]=holding CPU^current CPU, R2[0:7]=order */ + asm("tst r2, #0xE0 "); + asm("bne rwwuec_preemption "); /* This lock requires preemption to be disabled */ + + /* check interrupts disabled */ + asm("and r3, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("cmp r3, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* Check interrupts masked */ + asm("beq rwwuec_1 "); /* Yes - OK */ + __ASM_CRASH(); /* No - die */ + + asm("rwwuec_preemption: "); + asm("and r3, r2, #0xFF "); + asm("cmp r3, #0xFF "); /* check for EOrderNone */ + asm("ldrne r3, [r1, #%a0]" : : "i" _FOFF(TSubScheduler, iKernLockCount)); + asm("beq rwwuec_1 "); /* EOrderNone - don't check interrupts or preemption */ + asm("cmp r3, #0 "); + asm("bne rwwuec_1 "); /* Preemption disabled - OK */ + __ASM_CRASH(); /* Preemption enabled - die */ + + asm("rwwuec_1: "); + asm("tst r2, #0xFF00 "); /* Check if holding CPU ^ current CPU number == 0 */ + asm("beq rwwuec_2 "); /* Held by this CPU - OK */ + __ASM_CRASH(); /* Not held by this CPU - die */ + + asm("rwwuec_2: "); + asm("add r1, r1, #%a0" : : "i" _FOFF(TSubScheduler, iSpinLockOrderCheck)); + asm("mov r3, #0xFF "); + asm("strb r3, [r0, #7] "); /* reset holding CPU */ + asm("cmp r2, #0x40 "); + asm("bhs rwwuec_ok "); /* if EOrderNone, done */ + asm("cmp r2, #0x20 "); + asm("addhs r1, r1, #4 "); + asm("and r2, r2, #0x1F "); + asm("mov r3, #1 "); + asm("mov r3, r3, lsl r2 "); /* r3 = bit to clear */ + asm("ldr r2, [r1] "); + asm("tst r2, r3 "); /* test bit originally set */ + asm("bic r2, r2, r3 "); + asm("str r2, [r1] "); /* clear bit in iSpinLockOrderCheck corresponding to lock order */ + asm("bne rwwuec_ok "); /* if originally set, OK */ + __ASM_CRASH(); /* if not, die - something must have got corrupted */ + + asm("rwwuec_ok: "); + asm("msr cpsr, r12 "); /* restore interrupts */ + asm("ldmfd sp!, {r1,r2,r3,r12} "); + __JUMP(,lr); + } +#endif + + +/*----------------------------------------------------------------------------- + - Read locks disabling IRQ + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C void TRWSpinLock::LockIrqR() + { + __ASM_CLI(); /* Disable interrupts */ + RWSPIN_RLOCK_ENTRY_CHECK() + asm("1: "); + LDREX(1,0); + asm("and r2, r1, #0xFF "); /* R2 = original in.w */ + asm("add r1, r1, #0x100 "); /* increment in.r */ + asm("tst r1, #0xFF00 "); /* if wraparound ... */ + asm("subeq r1, r1, #0x10000 "); /* ... revert carry into out.w */ + STREX(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("3: "); + asm("and r1, r1, #0xFF0000 "); /* R1 = out.w << 16 */ + asm("cmp r1, r2, lsl #16 "); /* out.w = original in.w ? */ + asm("bne 2f "); /* no - must wait */ + RWSPIN_RLOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldr r1, [r0, #0] "); /* read out.w count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TRWSpinLock::UnlockIrqR() + { + RWSPIN_RUNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r3); /* Ensure accesses don't move outside locked section */ + asm("1: "); + LDREX(2,0); + asm("add r2, r2, #0x01000000 "); /* increment out.r */ + STREX(3,2,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + __DATA_SYNC_BARRIER__(r3); /* Ensure write to out.r completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + __ASM_STI(); /* Enable interrupts */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashIrqR() + { + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r12, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,i_GicCpuIfcAddr)); + asm("ldr r2, [r0, #0] "); + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(GicCpuIfc,iHighestPending)); + asm("eor r2, r2, r2, lsr #16 "); /* r2 low byte = out.w ^ in.w = 0 if no writers waiting */ + asm("tst r2, #0xFF "); + asm("addeq r3, r3, #1 "); + asm("cmpeq r3, #1024 "); /* if no writers waiting for lock, check for pending interrupt */ + asm("bne 1f "); /* branch if writers waiting or pending interrupt */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN11TRWSpinLock10UnlockIrqREv); + asm("bl " CSM_ZN11TRWSpinLock8LockIrqREv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +/*----------------------------------------------------------------------------- + - Write locks disabling IRQ + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C void TRWSpinLock::LockIrqW() + { + __ASM_CLI(); /* Disable interrupts */ + RWSPIN_WLOCK_ENTRY_CHECK() + asm("1: "); + LDREX(1,0); + asm("mov r2, r1, lsl #16 "); /* R2 = original in << 16 */ + asm("add r1, r1, #1 "); /* increment in.w */ + asm("tst r1, #0xFF "); /* if wraparound ... */ + asm("subeq r1, r1, #0x100 "); /* ... revert carry into in.r */ + STREX(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("3: "); + asm("mov r1, r1, lsr #16 "); /* r1 = out */ + asm("cmp r1, r2, lsr #16 "); /* out = original in ? */ + asm("bne 2f "); /* no - must wait */ + RWSPIN_WLOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldr r1, [r0, #0] "); /* read out count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TRWSpinLock::UnlockIrqW() + { + RWSPIN_WUNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r3); /* Ensure accesses don't move outside locked section */ + asm("ldrb r2, [r0, #2] "); + asm("add r2, r2, #1 "); + asm("strb r2, [r0, #2] "); /* increment out.w */ + __DATA_SYNC_BARRIER__(r3); /* Ensure write to out.w completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + __ASM_STI(); /* Enable interrupts */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashIrqW() + { + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r12, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,i_GicCpuIfcAddr)); + asm("ldr r2, [r0, #0] "); + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(GicCpuIfc,iHighestPending)); + asm("add r2, r2, #0x00010000 "); /* increment out.w */ + asm("tst r2, #0x00FF0000 "); /* if wraparound, revert carry */ + asm("subeq r2, r2, #0x01000000 "); + asm("eor r2, r2, r2, lsl #16 "); /* test if (out.w+1,out.r) == (in.w,in.r) */ + asm("cmp r2, #0x00010000 "); + asm("bhs 1f "); /* if not, someone else is waiting */ + asm("add r3, r3, #1 "); + asm("cmp r3, #1024 "); /* if no-one waiting for lock, check for pending interrupt */ + asm("bne 1f "); /* branch if pending interrupt */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN11TRWSpinLock10UnlockIrqWEv); + asm("bl " CSM_ZN11TRWSpinLock8LockIrqWEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + + +/*----------------------------------------------------------------------------- + - Read locks leaving IRQ alone + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C void TRWSpinLock::LockOnlyR() + { + RWSPIN_RLOCK_ENTRY_CHECK() + asm("1: "); + LDREX(1,0); + asm("and r2, r1, #0xFF "); /* R2 = original in.w */ + asm("add r1, r1, #0x100 "); /* increment in.r */ + asm("tst r1, #0xFF00 "); /* if wraparound ... */ + asm("subeq r1, r1, #0x10000 "); /* ... revert carry into out.w */ + STREX(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("3: "); + asm("and r1, r1, #0xFF0000 "); /* R1 = out.w << 16 */ + asm("cmp r1, r2, lsl #16 "); /* out.w = original in.w ? */ + asm("bne 2f "); /* no - must wait */ + RWSPIN_RLOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldr r1, [r0, #0] "); /* read out.w count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TRWSpinLock::UnlockOnlyR() + { + RWSPIN_RUNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r3); /* Ensure accesses don't move outside locked section */ + asm("1: "); + LDREX(2,0); + asm("add r2, r2, #0x01000000 "); /* increment out.r */ + STREX(3,2,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + __DATA_SYNC_BARRIER__(r3); /* Ensure write to out.r completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashOnlyR() + { + asm("ldr r2, [r0, #0] "); + asm("eor r2, r2, r2, lsr #16 "); /* r2 low byte = out.w ^ in.w = 0 if no writers waiting */ + asm("tst r2, #0xFF "); + asm("bne 1f "); /* branch if writers waiting */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN11TRWSpinLock11UnlockOnlyREv); + asm("bl " CSM_ZN11TRWSpinLock9LockOnlyREv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +/*----------------------------------------------------------------------------- + - Write locks leaving IRQ alone + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C void TRWSpinLock::LockOnlyW() + { + RWSPIN_WLOCK_ENTRY_CHECK() + asm("1: "); + LDREX(1,0); + asm("mov r2, r1, lsl #16 "); /* R2 = original in << 16 */ + asm("add r1, r1, #1 "); /* increment in.w */ + asm("tst r1, #0xFF "); /* if wraparound ... */ + asm("subeq r1, r1, #0x100 "); /* ... revert carry into in.r */ + STREX(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("3: "); + asm("mov r1, r1, lsr #16 "); /* r1 = out */ + asm("cmp r1, r2, lsr #16 "); /* out = original in ? */ + asm("bne 2f "); /* no - must wait */ + RWSPIN_WLOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldr r1, [r0, #0] "); /* read out count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TRWSpinLock::UnlockOnlyW() + { + RWSPIN_WUNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r3); /* Ensure accesses don't move outside locked section */ + asm("ldrb r2, [r0, #2] "); + asm("add r2, r2, #1 "); + asm("strb r2, [r0, #2] "); /* increment out.w */ + __DATA_SYNC_BARRIER__(r3); /* Ensure write to out.w completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashOnlyW() + { + asm("ldr r2, [r0, #0] "); + asm("add r2, r2, #0x00010000 "); /* increment out.w */ + asm("tst r2, #0x00FF0000 "); /* if wraparound, revert carry */ + asm("subeq r2, r2, #0x01000000 "); + asm("eor r2, r2, r2, lsl #16 "); /* test if (out.w+1,out.r) == (in.w,in.r) */ + asm("cmp r2, #0x00010000 "); + asm("bhs 1f "); /* if not, someone else is waiting */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN11TRWSpinLock11UnlockOnlyWEv); + asm("bl " CSM_ZN11TRWSpinLock9LockOnlyWEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + + +/*----------------------------------------------------------------------------- + - Read locks disabling IRQ with save/restore IRQ state + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C TInt TRWSpinLock::LockIrqSaveR() + { + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + RWSPIN_RLOCK_ENTRY_CHECK() + asm("1: "); + LDREX(1,0); + asm("and r2, r1, #0xFF "); /* R2 = original in.w */ + asm("add r1, r1, #0x100 "); /* increment in.r */ + asm("tst r1, #0xFF00 "); /* if wraparound ... */ + asm("subeq r1, r1, #0x10000 "); /* ... revert carry into out.w */ + STREX(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("3: "); + asm("and r1, r1, #0xFF0000 "); /* R1 = out.w << 16 */ + asm("cmp r1, r2, lsl #16 "); /* out.w = original in.w ? */ + asm("bne 2f "); /* no - must wait */ + RWSPIN_RLOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + asm("and r0, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* return original CPSR I and F bits */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldr r1, [r0, #0] "); /* read out.w count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TRWSpinLock::UnlockIrqRestoreR(TInt) + { + RWSPIN_RUNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r3); /* Ensure accesses don't move outside locked section */ + asm("1: "); + LDREX(2,0); + asm("add r2, r2, #0x01000000 "); /* increment out.r */ + STREX(3,2,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("mrs r12, cpsr "); + __DATA_SYNC_BARRIER__(r3); /* Ensure write to out.r completes before SEV */ + asm("bic r12, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + ARM_SEV; /* Wake up any waiting processors */ + asm("orr r1, r1, r12 "); + asm("msr cpsr, r1 "); /* restore interrupts */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashIrqRestoreR(TInt) + { + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r12, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,i_GicCpuIfcAddr)); + asm("ldr r2, [r0, #0] "); + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(GicCpuIfc,iHighestPending)); + asm("eor r2, r2, r2, lsr #16 "); /* r2 low byte = out.w ^ in.w = 0 if no writers waiting */ + asm("tst r2, #0xFF "); + asm("addeq r3, r3, #1 "); + asm("cmpeq r3, #1024 "); /* if no writers waiting for lock, check for pending interrupt */ + asm("bne 1f "); /* branch if writers waiting or pending interrupt */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN11TRWSpinLock17UnlockIrqRestoreREi); + asm("bl " CSM_ZN11TRWSpinLock8LockIrqREv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +/*----------------------------------------------------------------------------- + - Write locks disabling IRQ with save/restore IRQ state + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C TInt TRWSpinLock::LockIrqSaveW() + { + asm("mrs r12, cpsr "); + __ASM_CLI(); /* Disable interrupts */ + RWSPIN_WLOCK_ENTRY_CHECK() + asm("1: "); + LDREX(1,0); + asm("mov r2, r1, lsl #16 "); /* R2 = original in << 16 */ + asm("add r1, r1, #1 "); /* increment in.w */ + asm("tst r1, #0xFF "); /* if wraparound ... */ + asm("subeq r1, r1, #0x100 "); /* ... revert carry into in.r */ + STREX(3,1,0); + asm("cmp r3, #0 "); + asm("bne 1b "); + asm("3: "); + asm("mov r1, r1, lsr #16 "); /* r1 = out */ + asm("cmp r1, r2, lsr #16 "); /* out = original in ? */ + asm("bne 2f "); /* no - must wait */ + RWSPIN_WLOCK_MARK_ACQ() + __DATA_MEMORY_BARRIER__(r3); /* we have got the lock */ + asm("and r0, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); /* return original CPSR I and F bits */ + __JUMP(,lr); + + asm("2: "); + ARM_WFE; + asm("ldr r1, [r0, #0] "); /* read out count again */ + asm("b 3b "); + } + +__NAKED__ EXPORT_C void TRWSpinLock::UnlockIrqRestoreW(TInt) + { + RWSPIN_WUNLOCK_ENTRY_CHECK() + __DATA_MEMORY_BARRIER_Z__(r3); /* Ensure accesses don't move outside locked section */ + asm("ldrb r2, [r0, #2] "); + asm("mrs r12, cpsr "); + asm("add r2, r2, #1 "); + asm("bic r12, r12, #%a0" : : "i" ((TInt)KAllInterruptsMask)); + asm("strb r2, [r0, #2] "); /* increment out.w */ + __DATA_SYNC_BARRIER__(r3); /* Ensure write to out.w completes before SEV */ + ARM_SEV; /* Wake up any waiting processors */ + asm("orr r1, r1, r12 "); + asm("msr cpsr, r1 "); /* restore interrupts */ + __JUMP(,lr); + } + +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashIrqRestoreW(TInt) + { + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r12, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,i_GicCpuIfcAddr)); + asm("ldr r2, [r0, #0] "); + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(GicCpuIfc,iHighestPending)); + asm("add r2, r2, #0x00010000 "); /* increment out.w */ + asm("tst r2, #0x00FF0000 "); /* if wraparound, revert carry */ + asm("subeq r2, r2, #0x01000000 "); + asm("eor r2, r2, r2, lsl #16 "); /* test if (out.w+1,out.r) == (in.w,in.r) */ + asm("cmp r2, #0x00010000 "); + asm("bhs 1f "); /* if not, someone else is waiting */ + asm("add r3, r3, #1 "); + asm("cmp r3, #1024 "); /* if no-one else waiting for lock, check for pending interrupt */ + asm("bne 1f "); /* branch if pending interrupt */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("str lr, [sp, #-4]! "); + asm("bl " CSM_ZN11TRWSpinLock17UnlockIrqRestoreWEi); + asm("bl " CSM_ZN11TRWSpinLock8LockIrqWEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +/*----------------------------------------------------------------------------- + - Read lock flash allowing preemption + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashPreemptR() + { + asm("ldr r2, [r0, #0] "); + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,iRescheduleNeededFlag)); + asm("eor r2, r2, r2, lsr #16 "); /* r2 low byte = out.w ^ in.w = 0 if no writers waiting */ + asm("tst r2, #0xFF "); + asm("cmpeq r3, #0 "); /* if no writers waiting, check if reschedule or IDFCs pending */ + asm("bne 1f "); /* branch if so or if writers waiting */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("stmfd sp!, {r0,lr} "); + asm("bl " CSM_ZN11TRWSpinLock11UnlockOnlyREv); + asm("bl " CSM_ZN5NKern15PreemptionPointEv); + asm("ldr r0, [sp], #4 "); + asm("bl " CSM_ZN11TRWSpinLock9LockOnlyREv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } + + +/*----------------------------------------------------------------------------- + - Write lock flash allowing preemption + -----------------------------------------------------------------------------*/ +__NAKED__ EXPORT_C TBool TRWSpinLock::FlashPreemptW() + { + asm("ldr r2, [r0, #0] "); + GET_RWNO_TID(,r12); /* r12 -> TSubScheduler */ + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(TSubScheduler,iRescheduleNeededFlag)); + asm("add r2, r2, #0x00010000 "); /* increment out.w */ + asm("tst r2, #0x00FF0000 "); /* if wraparound, revert carry */ + asm("subeq r2, r2, #0x01000000 "); + asm("eor r2, r2, r2, lsl #16 "); /* test if (out.w+1,out.r) == (in.w,in.r) */ + asm("cmp r2, #0x00010000 "); + asm("bhs 1f "); /* if not, someone else is waiting */ + asm("cmp r3, #0 "); /* no-one else waiting, check if reschedule or IDFCs pending */ + asm("bne 1f "); /* if so, branch to release lock */ + asm("mov r0, #0 "); /* else return FALSE */ + __JUMP(,lr); + + asm("1: "); + asm("stmfd sp!, {r0,lr} "); + asm("bl " CSM_ZN11TRWSpinLock11UnlockOnlyWEv); + asm("bl " CSM_ZN5NKern15PreemptionPointEv); + asm("ldr r0, [sp], #4 "); + asm("bl " CSM_ZN11TRWSpinLock9LockOnlyWEv); + asm("mov r0, #1 "); + asm("ldr pc, [sp], #4 "); + } +