diff -r 000000000000 -r a41df078684a kernel/eka/memmodel/epoc/multiple/arm/xsched.cia --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/kernel/eka/memmodel/epoc/multiple/arm/xsched.cia Mon Oct 19 15:55:17 2009 +0100 @@ -0,0 +1,248 @@ +// Copyright (c) 1997-2009 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\arm\xsched.cia +// +// + +#include +#include +#include "nk_cpu.h" + +#define iMState iWaitLink.iSpare1 + +//#define __DEBUG_BAD_ADDR + +#ifdef __REQUEST_COMPLETE_MACHINE_CODED__ +#if defined(_DEBUG) +extern "C" void __DebugMsgRequestComplete(TInt a0, TInt a1, TInt a2); +extern "C" void __DebugMsgReqCompleteWrite(TInt a0, TInt a1, TInt a2); +#endif + +__NAKED__ void DThread::RequestComplete(TRequestStatus*& /*aStatus*/, TInt /*aReason*/) +// +// Signal this threads request semaphore. +// Enter with system locked, return with system unlocked. +// + { + ASM_DEBUG2(DThreadRequestComplete,r0,lr); + + asm("ldr r3, [r1] "); // r3 points to TRequestStatus + asm("mov r12, #0 "); + asm("str r12, [r1] "); // aStatus=NULL + + asm(".global _asm_RequestComplete "); + asm("_asm_RequestComplete: "); + +#ifdef BTRACE_REQUESTS + asm("stmdb sp!,{r0-r3,lr}"); + asm("mov r1,r3"); + asm("mov r3,r2"); // arg3 = aReason + asm("mov r2,r1"); // arg2 = aStatus + asm("add r1,r0,#%a0" : : "i" _FOFF(DThread,iNThread)); // arg1 = &this->iNThread + asm("ldr r0,_threadReqequestCompleteTraceHeader"); // arg0 = header + asm("bl " CSM_ZN6BTrace4OutXEmmmm); + asm("ldmia sp!,{r0-r3,lr}"); +#endif + + ASM_DEBUG3(RequestComplete,r0,r3,r2); + + // r0 -> DThread, r3 -> TRequestStatus in user space, r2 = aReason + asm("ldrb r12, [r0, #%a0]" : : "i" _FOFF(DThread,iMState)); + asm("ldr r1, __TheScheduler "); // r1->TheScheduler + asm("stmfd sp!, {r4-r9} "); + asm("add r6, r0, #%a0" : : "i" _FOFF(DThread,iNThread)); // r6->target NThread + asm("ldr r4, [r1, #%a0]" : : "i" _FOFF(TScheduler,iAddressSpace)); // r4->current process + asm("ldr r0, [r0, #%a0]" : : "i" _FOFF(DThread,iOwningProcess)); // r0->target process + asm("cmp r12, #%a0" : : "i" (DThread::EDead)); // test if iMState=EDead + asm("beq req_complete_dead_thread "); // if it is, finished + asm("ldr r5, [r1, #%a0]" : : "i" _FOFF(TScheduler,iCurrentThread)); // r5->current NThread + + asm("mrc p15, 0, r7, c2, c0, 0 "); // save TTBR0 + asm("ldr r9, [r0, #%a0]" : : "i" _FOFF(DMemModelProcess,iLocalPageDir)); // r9 -> target process page directory + asm("ldr r8, [r0, #%a0]" : : "i" _FOFF(DMemModelProcess,iOsAsid)); // r8 = target ASID + asm("and r12, r7, #%a0" : : "i" ((TInt)KTTBRExtraBitsMask)); // r12 = page table cache attributes + asm("orr r9, r9, r12 "); // r9 = target process TTBR0 value + asm("mrs r12, cpsr "); // save CPSR + CPSIDAIF; // disable all interrupts + asm("mcr p15, 0, r12, c7, c10, 4 "); // drain write buffer before changing MMU registers (see ARMv6 specs) + UPDATE_PW_CACHING_ATTRIBUTES(,r9); // ERRATUM 1136_317041 + asm("mcr p15, 0, r9, c2, c0, 0 "); // change TTBR0 + asm("mcr p15, 0, r8, c13, c0, 1 "); // change ASID + +#if defined(__CPU_ARM11MP__) + // On other platforms, tha ASID change above has already flushed the branch prediction buffers + asm("mcr p15, 0, r12, c7, c5, 6 "); // flush BTAC +#endif + + asm("str r0, [r1, #%a0]" : : "i" _FOFF(TScheduler,iAddressSpace)); + asm("str r0, [r5, #%a0]" : : "i" _FOFF(NThread,iAddressSpace)); + asm("msr cpsr, r12 "); // restore interrupts + + USER_MEMORY_GUARD_OFF(,r12,r12); + asm(".global __magic_address_reqc "); // NOTE: Z flag always clear here + asm("__magic_address_reqc: "); // this instruction is magically immune from exceptions + asm("strt r2, [r3] "); // store completion code with user permissions + // MAY MODIFY Z and R12 + USER_MEMORY_GUARD_ON(,r12,r12); + + asm("mrs r12, cpsr "); // save CPSR and Z flag which indicates whether write succeeded + asm("ldr r2, [r4, #%a0]" : : "i" _FOFF(DMemModelProcess,iOsAsid)); // r2 = current process ASID + CPSIDAIF; // disable all interrupts + asm("mcr p15, 0, r12, c7, c10, 4 "); // drain write buffer before changing MMU registers (see ARMv6 specs) + UPDATE_PW_CACHING_ATTRIBUTES(,r7); // ERRATUM 1136_317041 + asm("mcr p15, 0, r7, c2, c0, 0 "); // restore TTBR0 + asm("mcr p15, 0, r2, c13, c0, 1 "); // restore ASID + +#if defined(__CPU_ARM11MP__) + // On other platforms, tha ASID change above has already flushed the branch prediction buffers + asm("mcr p15, 0, r12, c7, c5, 6 "); // flush BTAC +#endif + + asm("str r4, [r1, #%a0]" : : "i" _FOFF(TScheduler,iAddressSpace)); + asm("str r4, [r5, #%a0]" : : "i" _FOFF(NThread,iAddressSpace)); + asm("msr cpsr, r12 "); // restore interrupts and Z flag + +#ifdef __DEBUG_BAD_ADDR + asm("moveq r12, #0xde000000 "); + asm("streq r12, [r12, #0xaf] "); //HACK-CRASH SYSTEM IF WRITE FAILED +#endif + + asm("movne r0, r6 "); // if write OK, r0->iNThread + asm("req_complete_dead_thread: "); // NOTE: Z flag set if thread dead + asm("ldmfd sp!, {r4-r9} "); // restore registers whether OK or not + asm("movne r1, #0 "); + asm("bne " CSM_ZN5NKern19ThreadRequestSignalEP7NThreadP10NFastMutex ); + asm("b " CSM_ZN5NKern12UnlockSystemEv); // if any error, unlock system and return + +#ifdef BTRACE_REQUESTS + asm("_threadReqequestCompleteTraceHeader:"); + asm(".word %a0" : : "i" (BTRACE_HEADER_C(16,BTrace::ERequests,BTrace::ERequestComplete))); +#endif + } +#endif + +GLDEF_C __NAKED__ void DoProcessSwitch() + { + // Enter and return with kernel locked + // r0->scheduler, r3->current thread + // r5->old process, r9->new process + // Return with r2 = (r2<<8) | ASID + // Must preserve r0,r3, can modify other registers + + // This code is optimized with the ARM1136 static branch prediction scheme in mind. + // Unusually, ARM1136 flushes the BTAC on every ContextID write whether it needs to + // or not! We only need to flush the prefetch if there's differing local code... -jls + + asm("cmp r5, r9 "); // check if current address space correct + asm("beq address_switch_done"); // skip if address space change not required + + asm("mrc p15, 0, r1, c2, c0, 0 "); // get TTBR0 + asm("ldr r4, [r9, #%a0]" : : "i" _FOFF(DMemModelProcess, iLocalPageDir)); + asm("and r1, r1, #%a0" : : "i" ((TInt)KTTBRExtraBitsMask)); // r1 = page table cache attributes + asm("str r9, [r0, #%a0]" : : "i" _FOFF(TScheduler, iAddressSpace)); + asm("orr r4, r4, r1 "); // r4 = new TTBR0 value + asm("ldr r1, [r9, #%a0]" : : "i" _FOFF(DMemModelProcess, iSelfModChunks)); + asm("mcr p15, 0, r4, c7, c10, 4 "); // drain write buffer before changing MMU registers (see ARMv6 specs) + UPDATE_PW_CACHING_ATTRIBUTES(,r4); // ERRATUM 1136_317041 + asm("mcr p15, 0, r4, c2, c0, 0 "); // set TTBR0 - no TLB flush required due to ASID + asm("cmp r1, #0"); // do we have selfmod chunks? (probably not) + asm("bgt gotchunks "); // yes, so we need to look closer (will predict not taken) + + asm("address_switch_done:"); + asm("ldr r4, [r9, #%a0]" : : "i" _FOFF(DMemModelProcess, iOsAsid)); + asm("ldr r6, [r3, #%a0]" : : "i" (_FOFF(DMemModelThread, iAliasLinAddr)-_FOFF(DThread, iNThread)) ); + asm("orr r2, r4, r2, lsl #8 "); // r2 = original r2 << 8 | ASID + asm("cmp r6, #0"); // check if thread has an alias in place + asm("bne got_alias"); + __JUMP(,lr); + + // restore alias... + asm("got_alias:"); + asm("ldr r7, [r3, #%a0]" : : "i" (_FOFF(DMemModelThread, iAliasPde)-_FOFF(DThread, iNThread)) ); + asm("ldr r1, [r0, #%a0]" : : "i" _FOFF(TScheduler, iExtras[1])); // Alias remap old address + asm("ldr r8, [r3, #%a0]" : : "i" (_FOFF(DMemModelThread, iAliasPdePtr)-_FOFF(DThread, iNThread)) ); + asm("orr r6, r6, r4"); // put ASID into address for TLB flush later... + asm("eor r1, r1, r7 "); // compare old address with pde + asm("cmp r1, #0x1000 "); // if result only has perm bits, addresses were the same + asm("blo remap_alias "); + + asm("alias_remap_done: "); + asm("str r7, [r8]"); // restore PDE for alias + + CACHE_MAINTENANCE_PDE_PTE_UPDATED(r8); + +#ifdef __CPU_ARMV7 + UTLBIMVA(r6); + ARM_DSBSH; + ARM_ISBSY; +#else + FLUSH_DTLB_ENTRY(,r6); // flush TLB for aliased page +#endif + __JUMP(,lr); + + asm("remap_alias: "); + asm("ldr r7, [r0, #%a0]" : : "i" _FOFF(TScheduler, iExtras[2])); // Alias remap new address + asm("orr r7, r1, r7 "); // r1 has perm bits, left over from xor above + asm("b alias_remap_done "); + + asm("gotchunks: "); + asm("ldr r1, [r0, #%a0]" : : "i" _FOFF(TScheduler, iExtras[0])); // address of last selfmod process + asm("cmp r1, r9"); // was it whoever's next up? (probably) + asm("beq address_switch_done"); + asm("mcr p15, 0, r4, c7, c5, 4 "); // prefetch flush before returning +#ifdef __CPU_HAS_UNFLUSHED_BTB +#ifdef __CPU_ARMV7 + BPIALL; +#else + FLUSH_BTB(,r1); // flush the dynamic branch predictor table +#endif +#endif + asm("str r9, [r0, #%a0]" : : "i" _FOFF(TScheduler, iExtras[0])); // update it + asm("b address_switch_done"); + + asm("__TheScheduler: "); + asm(".word TheScheduler "); + }; + +/** +Restore the address space of the current thread so it matches its owning process. +*/ +__NAKED__ void DMemModelThread::RestoreAddressSpace() + { + asm("ldr r12, __TheScheduler "); // r12->TheScheduler + asm("ldr r3, [r12, #%a0]" : : "i" _FOFF(TScheduler,iCurrentThread)); // r3->current NThread + asm("ldr r0, [r3, #%a0]" : : "i" (-_FOFF(DThread,iNThread)+_FOFF(DThread,iOwningProcess))); // r0->process + + // switch address space to process r0... + asm("ldr r1, [r0, #%a0]" : : "i" _FOFF(DMemModelProcess,iLocalPageDir));// r1->process page directory + asm("mrc p15, 0, r2, c2, c0, 0 "); // get TTBR0 + asm("and r2, r2, #%a0" : : "i" ((TInt)KTTBRExtraBitsMask)); // r2 = page table cache attributes + asm("orr r1, r1, r2 "); // r1 = new TTBR0 value + asm("ldr r2, [r0, #%a0]" : : "i" _FOFF(DMemModelProcess,iOsAsid)); // r2 = ASID + CPSIDAIF; // disable all interrupts + asm("mcr p15, 0, r2, c7, c10, 4 "); // drain write buffer before changing MMU registers (see ARMv6 specs) + UPDATE_PW_CACHING_ATTRIBUTES(,r1); // ERRATUM 1136_317041 + asm("mcr p15, 0, r1, c2, c0, 0 "); // change TTBR0 + asm("mcr p15, 0, r2, c13, c0, 1 "); // change ASID + +#if defined(__CPU_ARM11MP__) + // On other platforms, tha ASID change above has already flushed the branch prediction buffers + asm("mcr p15, 0, r2, c7, c5, 6 "); // flush BTAC +#endif + + asm("str r0, [r12, #%a0]" : : "i" _FOFF(TScheduler,iAddressSpace)); + asm("str r0, [r3, #%a0]" : : "i" _FOFF(NThread,iAddressSpace)); + CPSIEAIF; // enable all interrupts + __JUMP(,lr); + }