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1.1 ! root 1: /* ! 2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. ! 3: * ! 4: * @APPLE_LICENSE_HEADER_START@ ! 5: * ! 6: * The contents of this file constitute Original Code as defined in and ! 7: * are subject to the Apple Public Source License Version 1.1 (the ! 8: * "License"). You may not use this file except in compliance with the ! 9: * License. Please obtain a copy of the License at ! 10: * http://www.apple.com/publicsource and read it before using this file. ! 11: * ! 12: * This Original Code and all software distributed under the License are ! 13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER ! 14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, ! 15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, ! 16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the ! 17: * License for the specific language governing rights and limitations ! 18: * under the License. ! 19: * ! 20: * @APPLE_LICENSE_HEADER_END@ ! 21: */ ! 22: #include <ppc/asm.h> ! 23: #include <ppc/proc_reg.h> ! 24: #include <ppc/exception.h> ! 25: #include <mach/ppc/vm_param.h> ! 26: #include <assym.s> ! 27: ! 28: /* ! 29: ** Blue Box Fast Trap entry ! 30: ** ! 31: ** The registers at entry are as hw_exceptions left them. Which means ! 32: ** that the Blue Box data area is pointed to be R26. ! 33: ** ! 34: ** We exit here through the fast path exit point in hw_exceptions. That means that ! 35: ** upon exit, R4 must not change. It is the savearea with the current user context ! 36: ** to restore. ! 37: ** ! 38: ** Input registers are: ! 39: ** r4 = Current context savearea (do not modify) ! 40: ** r9 = THREAD_TOP_ACT pointer ! 41: ** r24 = Offset into Call Descriptor table ! 42: ** r26 = base of ACT_MACH_BDA in kernel address space ! 43: ** ! 44: ** ! 45: */ ! 46: ! 47: ENTRY(atomic_switch_trap, TAG_NO_FRAME_USED) ! 48: ! 49: /* ! 50: ** functions 0-13, 15 -> Call PseudoKernel ! 51: ** 14 -> Exit PseudoKernel ! 52: */ ! 53: ! 54: cmplwi cr7,r24,BBEXITTRAP*PKTDSIZE ; Is this an exit? ! 55: add r24,r24,r26 ; Point to the actual entry offset+base ! 56: beq cr7,.L_ExitPseudoKernel ; Yes... ! 57: ! 58: /****************************************************************************** ! 59: * void CallPseudoKernel ( void ) ! 60: * ! 61: * This op provides a means of invoking the BlueBox PseudoKernel from a ! 62: * system (68k) or native (PPC) context while changing BlueBox interruption ! 63: * state atomically. As an added bonus, this op leaves the user state ! 64: * registers intact. ! 65: * ! 66: * This op is invoked from the Emulator Trap dispatch table. The kernel is ! 67: * aware of starting address of this table. It uses the users PC (SS_SRR0) ! 68: * and the Trap dispatch table address to verify the trap exception as a ! 69: * atomic_switch trap. If a trap exception is verified as a atomic_switch ! 70: * we enter here with the following registers loaded. ! 71: * ! 72: * Input registers are: ! 73: * r4 = Current context savearea (do not modify) ! 74: * r24 = Offset into PseudoKernel Trap Descriptor table ! 75: * r26 = Base address of BlueBox Data in kernel address space ! 76: * ! 77: ********************************************************************************/ ! 78: ! 79: lwz r8,BDA_INTCONTROLWORD(r26) ; Get the interruption control word (ICW) ! 80: lis r9,SYSCONTEXTSTATE ; Load system context constant ! 81: rlwinm r7,r8,0,INTSTATEMASK_B,INTSTATEMASK_E ; extract the current state from interruption control word ! 82: lwz r6,BDA_PKTD_NEWSTATE(r24) ; Get the new context state ! 83: cmplw r7,r9 ; test for entry from system context ! 84: rlwimi r8,r6,0,INTSTATEMASK_B,INTSTATEMASK_E ; insert the new state into interruption control word ! 85: lwz r7,savecr(r4) ; Get the CR at interruption time ! 86: bne .L_CallFromAlternateContext ; We were in the alternate context... ! 87: rlwimi r8,r7,32-INTCR2TOBACKUPSHIFT,INTBACKUPCR2MASK_B,INTBACKUPCR2MASK_E ! 88: ; remove old backup CR2 and insert live CR2 into backup CR2 position ! 89: ! 90: .L_CallFromAlternateContext: ! 91: lwz r5,saver2(r4) ; Get live R2 ! 92: lwz r6,BDA_PKTD_PC(r24) ; Get the PC ! 93: lwz r7,savesrr1(r4) ; Get the interrupt-time MSR value ! 94: stw r8,BDA_INTCONTROLWORD(r26) ; update interruption control word ! 95: rlwinm r7,r7,0,MSR_FE1_BIT,MSR_FE0_BIT ; Clear BE and SE bits ! 96: stw r5,BDA_PKTD_REG(r24) ; Save R2 into call descriptor ! 97: stw r6,savesrr0(r4) ; Set the new instruction address ! 98: stw r7,savesrr1(r4) ; Set the updated msr ! 99: b EXT(fastexit) ; Go back and take the fast path exit... ! 100: ! 101: ! 102: /******************************************************************************* ! 103: * void ExitPseudoKernel ( ExitPseudoKernelDescriptorPtr exitDescriptor ) ! 104: * ! 105: * This op provides a means of exiting from the BlueBox PseudoKernel to a ! 106: * user context while changing the BlueBox interruption state atomically. ! 107: * It also allows the MSR's FE0,BE,SE and FE1 bits to updated for the user ! 108: * and completes the PPC register loading. ! 109: * ! 110: * Input registers are: ! 111: * r4 = Current context savearea (do not modify) ! 112: * r24 = Offset into PseudoKernel Trap Descriptor table ! 113: * r26 = Base address of BlueBox Data in kernel address space ! 114: * ! 115: *********************************************************************************/ ! 116: ! 117: .L_ExitPseudoKernel: ! 118: lwz r9,savesrr1(r4) ; Pick up the old MSR value ! 119: lwz r8,savecr(r4) ; Get the live CR value ! 120: lwz r7,BDA_PKTD_NEWSTATE(r24) ; Get the new state ! 121: lis r0,SYSCONTEXTSTATE ; Get the system context constant ! 122: lwz r10,BDA_INTCONTROLWORD(r26) ; Get Interruption Control Word (ICW) ! 123: lwz r6,BDA_PKTD_PC(r24) ; Get the brand-new spanking clean inst address ! 124: cmplw r7,r0 ; Are we going system context? ! 125: lwz r5,BDA_PKTD_MSR(r24) ; Pick up new MSR state ! 126: rlwimi r10,r7,0,INTSTATEMASK_B,INTSTATEMASK_E ! 127: ; Insert the new state into interruption control word ! 128: beq .L_ExitToSystemContext ; We are going to system context... ! 129: lwz r7,BDA_TESTINTMASK(r26) ; Get the pending interrupt mask ! 130: lwz r14,BDA_PKTD_INTPENDINGPC(r26) ; Get the interruption exit address ! 131: and. r7,r10,r7 ; test for pending interrupt in backup cr2 ! 132: beq .L_ExitUpdateRuptControlWord ; and enter alternate context if none pending ! 133: mr r6,r14 ; otherwise, introduce entry abort pc ! 134: b .L_ExitNoUpdateRuptControlWord ; and prepare to reenter pseudokernel ! 135: ! 136: .L_ExitToSystemContext: ! 137: rlwimi r8,r10,INTCR2TOBACKUPSHIFT,INTCR2MASK_B,INTCR2MASK_E ! 138: ; remove old CR2 and insert backup CR2 into live CR2 position ! 139: .L_ExitUpdateRuptControlWord: ! 140: rlwimi r9,r5,0,MSR_FE0_BIT,MSR_FE1_BIT ; Insert FE0, BE, SE and FE1 into MSR ! 141: stw r10,BDA_INTCONTROLWORD(r26) ; update the interrupt control word ! 142: ! 143: .L_ExitNoUpdateRuptControlWord: ! 144: lwz r7,BDA_PKTD_REG(r24) ; Get the new CTR ! 145: stw r6,savesrr0(r4) ; Set the new PC ! 146: stw r7,savectr(r4) ; Set the new CTR ! 147: stw r8,savecr(r4) ; Set the new CR ! 148: stw r9,savesrr1(r4) ; Set the new MSR ! 149: ! 150: b EXT(fastexit) ; Go back and take the fast path exit... ! 151:
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