/* * Copyright (c) 2002 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_OSREFERENCE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the * License may not be used to create, or enable the creation or * redistribution of, unlawful or unlicensed copies of an Apple operating * system, or to circumvent, violate, or enable the circumvention or * violation of, any terms of an Apple operating system software license * agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_OSREFERENCE_HEADER_END@ */ /* Emulate64.s * * Software emulation of instructions not handled in hw, on 64-bit machines. */ #include #include #include #include #include #include #include // CR bit set if the instruction is an "update" form (LFDU, STWU, etc): #define kUpdate 25 // CR bit set if interrupt occured in trace mode (ie, MSR_SE_BIT): #define kTrace 8 // CR bit set if notification on alignment interrupts is requested (notifyUnalignbit in spcFlags): #define kNotify 9 // CR bit distinguishes between alignment and program exceptions: #define kAlignment 10 // ************************************* // * P R O G R A M I N T E R R U P T * // ************************************* // // These are floating pt exceptions, illegal instructions, privileged mode violations, // and traps. All we're interested in at this low level is illegal instructions. // The ones we "emulate" are: // DCBA, which is not implemented in the IBM 970. The emulation is to ignore it, // as it is just a hint. // MCRXR, which is not implemented on the IBM 970, but is in the PPC ISA. // // Additionally, to facilitate debugging the alignment handler, we recognize a special // diagnostic mode that is used to simulate alignment exceptions. When in this mode, // if the instruction has opcode==0 and the extended opcode is one of the X-form // instructions that can take an alignment interrupt, then we change the opcode to // 31 and pretend it got an alignment interrupt. This exercises paths that // are hard to drive or perhaps never driven on this particular CPU. .text .globl EXT(Emulate64) .align 5 LEXT(Emulate64) crclr kAlignment // not an alignment exception b a64AlignAssistJoin // join alignment handler // Return from alignment handler with all the regs loaded for opcode emulation. a64HandleProgramInt: rlwinm. r0,r29,0,SRR1_PRG_ILL_INS_BIT,SRR1_PRG_ILL_INS_BIT // illegal opcode? beq a64PassAlong // No, must have been trap or priv violation etc rlwinm r3,r20,6,26,31 // right justify opcode field (bits 0-5) rlwinm r4,r20,31,22,31 // right justify extended opcode field (bits 21-30) cmpwi cr0,r3,31 // X-form? cmpwi cr1,r4,758 // DCBA? cmpwi cr4,r4,512 // MCRXR? crand cr1_eq,cr0_eq,cr1_eq // merge the two tests for DCBA crand cr4_eq,cr0_eq,cr4_eq // and for MCRXR beq++ cr1_eq,a64ExitEm // was DCBA, so ignore bne-- cr4_eq,a64NotEmulated // skip if not MCRXR // Was MCRXR, so emulate. ld r3,savexer(r13) // get the XER lwz r4,savecr(r13) // and the CR rlwinm r5,r20,11,27,29 // get (CR# * 4) from instruction rlwinm r6,r3,0,4,31 // zero XER[32-35] (also XER[0-31]) sld r4,r4,r5 // move target CR field to bits 32-35 rlwimi r4,r3,0,0,3 // move XER[32-35] into CR field stw r6,savexer+4(r13) // update XER srd r4,r4,r5 // re-position CR stw r4,savecr(r13) // update CR b a64ExitEm // done // Not an opcode we normally emulate. If in special diagnostic mode and opcode=0, // emulate as an alignment exception. This special case is for test software. a64NotEmulated: lwz r30,dgFlags(0) // Get the flags rlwinm. r0,r30,0,enaDiagEMb,enaDiagEMb // Do we want to try to emulate something? beq++ a64PassAlong // No emulation allowed cmpwi r3,0 // opcode==0 ? bne a64PassAlong // not the special case oris r20,r20,0x7C00 // change opcode to 31 crset kAlignment // say we took alignment exception rlwinm r5,r4,0,26+1,26-1 // mask Update bit (32) out of extended opcode rlwinm r5,r5,0,0,31 // Clean out leftover junk from rlwinm cmpwi r4,1014 // dcbz/dcbz128 ? crmove cr1_eq,cr0_eq cmpwi r5,21 // ldx/ldux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,599 // lfdx/lfdux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,535 // lfsx/lfsux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,343 // lhax/lhaux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,790 // lhbrx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,279 // lhzx/lhzux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,597 // lswi ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,533 // lswx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,341 // lwax/lwaux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,534 // lwbrx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,23 // lwz/lwzx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,149 // stdx/stdux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,727 // stfdx/stfdux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,983 // stfiwx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,663 // stfsx/stfsux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,918 // sthbrx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,407 // sthx/sthux ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,725 // stswi ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,661 // stswx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r4,662 // stwbrx ? cror cr1_eq,cr0_eq,cr1_eq cmpwi r5,151 // stwx/stwux ? cror cr1_eq,cr0_eq,cr1_eq beq++ cr1,a64GotInstruction // it was one of the X-forms we handle crclr kAlignment // revert to program interrupt b a64PassAlong // not recognized extended opcode // ***************************************** // * A L I G N M E N T I N T E R R U P T * // ***************************************** // // We get here in exception context, ie with interrupts disabled, translation off, and // in 64-bit mode, with: // r13 = save-area pointer, with general context already saved in it // cr6 = feature flags // We preserve r13 and cr6. Other GPRs and CRs, the LR and CTR are used. // // Current 64-bit processors (GPUL) handle almost all misaligned operations in hardware, // so this routine usually isn't called very often. Only floating pt ops that cross a page // boundary and are not word aligned, and LMW/STMW can take exceptions to cacheable memory. // However, in contrast to G3 and G4, any misaligned load/store will get an alignment // interrupt on uncached memory. // // We always emulate scalar ops with a series of byte load/stores. Doing so is no slower // than LWZ/STW in cases where a scalar op gets an alignment exception. // // This routine supports all legal permutations of alignment interrupts occuring in user or // supervisor mode, 32 or 64-bit addressing, and translation on or off. We do not emulate // instructions that go past the end of an address space, such as "LHZ -1(0)"; we just pass // along the alignment exception rather than wrap around to byte 0. // // First, check for a few special cases such as virtual machines, etc. .globl EXT(AlignAssist64) .align 5 LEXT(AlignAssist64) crset kAlignment // mark as alignment interrupt a64AlignAssistJoin: // join here from program interrupt handler li r0,0 // Get a 0 mfsprg r31,0 // get the per_proc data ptr mcrf cr3,cr6 // save feature flags here... lwz r21,spcFlags(r31) // grab the special flags ld r29,savesrr1(r13) // get the MSR etc at the fault ld r28,savesrr0(r13) // get the EA of faulting instruction stw r0,savemisc3(r13) // Assume we will handle this ok mfmsr r26 // save MSR at entry rlwinm. r0,r21,0,runningVMbit,runningVMbit // Are we running a VM? lwz r19,dgFlags(0) // Get the diagnostics flags bne-- a64PassAlong // yes, let the virtual machine monitor handle // Set up the MSR shadow regs. We turn on FP in this routine, and usually set DR and RI // when accessing user space (the SLB is still set up with all the user space translations.) // However, if the interrupt occured in the kernel with DR off, we keep it off while // accessing the "target" address space. If we set DR to access the target space, we also // set RI. The RI bit tells the exception handlers to clear cr0 beq and return if we get an // exception accessing the user address space. We are careful to test cr0 beq after every such // access. We keep the following "shadows" of the MSR in global regs across this code: // r25 = MSR at entry, plus FP and probably DR and RI (used to access target space) // r26 = MSR at entry // r27 = free // r29 = SRR1 (ie, MSR at interrupt) // Note that EE and IR are always off, and SF is always on in this code. rlwinm r3,r29,0,MSR_DR_BIT,MSR_DR_BIT // was translation on at fault? rlwimi r3,r3,32-MSR_RI_BIT+MSR_DR_BIT,MSR_RI_BIT,MSR_RI_BIT // if DR was set, set RI too or r25,r26,r3 // assemble MSR to use accessing target space // Because the DSISR and DAR are either not set or are not to be trusted on some 64-bit // processors on an alignment interrupt, we must fetch the faulting instruction ourselves, // then decode/hash the opcode and reconstruct the EA manually. mtmsr r25 // turn on FP and (if it was on at fault) DR and RI isync // wait for it to happen cmpw r0,r0 // turn on beq so we can check for DSIs lwz r20,0(r28) // fetch faulting instruction, probably with DR on bne-- a64RedriveAsISI // got a DSI trying to fetch it, pretend it was an ISI mtmsr r26 // turn DR back off isync // wait for it to happen // Set a few flags while we wait for the faulting instruction to arrive from cache. rlwinm. r0,r29,0,MSR_SE_BIT,MSR_SE_BIT // Were we single stepping? stw r20,savemisc2(r13) // Save the instruction image in case we notify crnot kTrace,cr0_eq rlwinm. r0,r19,0,enaNotifyEMb,enaNotifyEMb // Should we notify? crnot kNotify,cr0_eq // Hash the intruction into a 5-bit value "AAAAB" used to index the branch table, and a // 1-bit kUpdate flag, as follows: // ¥ for X-form instructions (with primary opcode 31): // the "AAAA" bits are bits 21-24 of the instruction // the "B" bit is the XOR of bits 29 and 30 // the update bit is instruction bit 25 // ¥ for D and DS-form instructions (actually, any primary opcode except 31): // the "AAAA" bits are bits 1-4 of the instruction // the "B" bit is 0 // the update bit is instruction bit 5 // // Just for fun (and perhaps a little speed on deep-pipe machines), we compute the hash, // update flag, and EA without branches and with ipc >= 2. // // When we "bctr" to the opcode-specific reoutine, the following are all set up: // MSR = EE and IR off, SF and FP on // r12 = full 64-bit EA (r17 is clamped EA) // r13 = save-area pointer (physical) // r14 = ptr to saver0 in save-area (ie, to base of GPRs) // r15 = 0x00000000FFFFFFFF if 32-bit mode fault, 0xFFFFFFFFFFFFFFFF if 64 // r16 = RA * 8 (ie, reg# not reg value) // r17 = EA, clamped to 32 bits if 32-bit mode fault (see also r12) // r18 = (RA|0) (reg value) // r19 = -1 if X-form, 0 if D-form // r20 = faulting instruction // r21 = RT * 8 (ie, reg# not reg value) // r22 = addr(aaFPopTable)+(RT*32), ie ptr to floating pt table for target register // r25 = MSR at entrance, probably with DR and RI set (for access to target space) // r26 = MSR at entrance // r27 = free // r28 = SRR0 (ie, EA of faulting instruction) // r29 = SRR1 (ie, MSR at fault) // r30 = scratch, usually user data // r31 = per-proc pointer // cr2 = kTrace, kNotify, and kAlignment flags // cr3 = saved copy of feature flags used in lowmem vector code // cr6 = bits 24-27 of CR are bits 24-27 of opcode if X-form, or bits 4-5 and 00 if D-form // bit 25 is the kUpdate flag, set for update form instructions // cr7 = bits 28-31 of CR are bits 28-31 of opcode if X-form, or 0 if D-form a64GotInstruction: // here from program interrupt with instruction in r20 rlwinm r21,r20,6+6,20,25 // move the primary opcode (bits 0-6) to bits 20-25 la r14,saver0(r13) // r14 <- base address of GPR registers xori r19,r21,0x07C0 // iff primary opcode is 31, set r19 to 0 rlwinm r16,r20,16+3,24,28 // r16 <- RA*8 subi r19,r19,1 // set bit 0 iff X-form (ie, if primary opcode is 31) rlwinm r17,r20,21+3,24,28 // r17 <- RB*8 (if X-form) sradi r19,r19,63 // r19 <- -1 if X-form, 0 if D-form extsh r22,r20 // r22 <- displacement (if D-form) ldx r23,r14,r17 // get (RB), if any and r15,r20,r19 // instruction if X, 0 if D andc r17,r21,r19 // primary opcode in bits 20-25 if D, 0 if X ldx r18,r14,r16 // get (RA) subi r24,r16,1 // set bit 0 iff RA==0 or r21,r15,r17 // r21 <- instruction if X, or bits 0-5 in bits 20-25 if D sradi r24,r24,63 // r24 <- -1 if RA==0, 0 otherwise rlwinm r17,r21,32-4,25,28 // shift opcode bits 21-24 to 25-28 (hash "AAAA" bits) lis r10,ha16(a64BranchTable) // start to build up branch table address rlwimi r17,r21,0,29,29 // move opcode bit 29 into hash as start of "B" bit rlwinm r30,r21,1,29,29 // position opcode bit 30 in position 29 and r12,r23,r19 // RB if X-form, 0 if D-form andc r11,r22,r19 // 0 if X-form, sign extended displacement if D-form xor r17,r17,r30 // bit 29 ("B") of hash is xor(bit29,bit30) addi r10,r10,lo16(a64BranchTable) or r12,r12,r11 // r12 <- (RB) or displacement, as appropriate lwzx r30,r10,r17 // get address from branch table mtcrf 0x01,r21 // move opcode bits 28-31 to CR7 sradi r15,r29,32 // propogate SF bit from SRR1 (MSR_SF, which is bit 0) andc r18,r18,r24 // r18 <- (RA|0) mtcrf 0x02,r21 // move opcode bits 24-27 to CR6 (kUpdate is bit 25) add r12,r18,r12 // r12 <- 64-bit EA mtctr r30 // set up branch address oris r15,r15,0xFFFF // start to fill low word of r15 with 1s rlwinm r21,r20,11+3,24,28 // r21 <- RT * 8 lis r22,ha16(EXT(aaFPopTable)) // start to compute address of floating pt table ori r15,r15,0xFFFF // now bits 32-63 of r15 are 1s addi r22,r22,lo16(EXT(aaFPopTable)) and r17,r12,r15 // clamp EA to 32 bits if fault occured in 32-bit mode rlwimi r22,r21,2,22,26 // move RT into aaFPopTable address (which is 1KB aligned) bf-- kAlignment,a64HandleProgramInt // return to Program Interrupt handler bctr // if alignment interrupt, jump to opcode-specific routine // Floating-pt load single (lfs[u], lfsx[u]) a64LfsLfsx: bl a64Load4Bytes // get data in r30 mtctr r22 // set up address of "lfs fRT,emfp0(r31)" stw r30,emfp0(r31) // put word here for aaFPopTable routine bctrl // do the lfs b a64UpdateCheck // update RA if necessary and exit // Floating-pt store single (stfs[u], stfsx[u]) a64StfsStfsx: ori r22,r22,8 // set dir==1 (ie, single store) in aaFPopTable mtctr r22 // set up address of "stfs fRT,emfp0(r31)" bctrl // execute the store into emfp0 lwz r30,emfp0(r31) // get the word bl a64Store4Bytes // store r30 into user space b a64UpdateCheck // update RA if necessary and exit // Floating-pt store as integer word (stfiwx) a64Stfiwx: ori r22,r22,16+8 // set size=1, dir==1 (ie, double store) in aaFPopTable mtctr r22 // set up FP register table address bctrl // double precision store into emfp0 lwz r30,emfp0+4(r31) // get the low-order word bl a64Store4Bytes // store r30 into user space b a64Exit // successfully emulated // Floating-pt load double (lfd[u], lfdx[u]) a64LfdLfdx: ori r22,r22,16 // set Double bit in aaFPopTable address bl a64Load8Bytes // get data in r30 mtctr r22 // set up address of "lfd fRT,emfp0(r31)" std r30,emfp0(r31) // put doubleword here for aaFPopTable routine bctrl // execute the load b a64UpdateCheck // update RA if necessary and exit // Floating-pt store double (stfd[u], stfdx[u]) a64StfdStfdx: ori r22,r22,16+8 // set size=1, dir==1 (ie, double store) in aaFPopTable address mtctr r22 // address of routine to stfd RT bctrl // store into emfp0 ld r30,emfp0(r31) // get the doubleword bl a64Store8Bytes // store r30 into user space b a64UpdateCheck // update RA if necessary and exit // Load halfword w 0-fill (lhz[u], lhzx[u]) a64LhzLhzx: bl a64Load2Bytes // load into r30 from user space (w 0-fill) stdx r30,r14,r21 // store into RT slot in register file b a64UpdateCheck // update RA if necessary and exit // Load halfword w sign fill (lha[u], lhax[u]) a64LhaLhax: bl a64Load2Bytes // load into r30 from user space (w 0-fill) extsh r30,r30 // sign-extend stdx r30,r14,r21 // store into RT slot in register file b a64UpdateCheck // update RA if necessary and exit // Load halfword byte reversed (lhbrx) a64Lhbrx: bl a64Load2Bytes // load into r30 from user space (w 0-fill) rlwinm r3,r30,8,16,23 // reverse bytes into r3 rlwimi r3,r30,24,24,31 stdx r3,r14,r21 // store into RT slot in register file b a64Exit // successfully emulated // Store halfword (sth[u], sthx[u]) a64SthSthx: ldx r30,r14,r21 // get RT bl a64Store2Bytes // store r30 into user space b a64UpdateCheck // update RA if necessary and exit // Store halfword byte reversed (sthbrx) a64Sthbrx: addi r21,r21,6 // point to low two bytes of RT lhbrx r30,r14,r21 // load and reverse bl a64Store2Bytes // store r30 into user space b a64Exit // successfully emulated // Load word w 0-fill (lwz[u], lwzx[u]), also lwarx. a64LwzLwzxLwarx: andc r3,r19,r20 // light bit 30 of r3 iff lwarx andi. r0,r3,2 // is it lwarx? bne-- a64PassAlong // yes, never try to emulate a lwarx bl a64Load4Bytes // load 4 bytes from user space into r30 (0-filled) stdx r30,r14,r21 // update register file b a64UpdateCheck // update RA if necessary and exit // Load word w sign fill (lwa, lwax[u]) a64Lwa: crclr kUpdate // no update form of lwa (its a reserved encoding) a64Lwax: bl a64Load4Bytes // load 4 bytes from user space into r30 (0-filled) extsw r30,r30 // sign extend stdx r30,r14,r21 // update register file b a64UpdateCheck // update RA if necessary and exit // Load word byte reversed (lwbrx) a64Lwbrx: bl a64Load4Bytes // load 4 bytes from user space into r30 (0-filled) rlwinm r3,r30,24,0,31 // flip bytes 1234 to 4123 rlwimi r3,r30,8,8,15 // r3 is now 4323 rlwimi r3,r30,8,24,31 // r3 is now 4321 stdx r3,r14,r21 // update register file b a64Exit // successfully emulated // Store word (stw[u], stwx[u]) a64StwStwx: ldx r30,r14,r21 // get RT bl a64Store4Bytes // store r30 into user space b a64UpdateCheck // update RA if necessary and exit // Store word byte reversed (stwbrx) a64Stwbrx: addi r21,r21,4 // point to low word of RT lwbrx r30,r14,r21 // load and reverse bl a64Store4Bytes // store r30 into user space b a64Exit // successfully emulated // Load doubleword (ld[u], ldx[u]), also lwa. a64LdLwa: // these are DS form: ld=0, ldu=1, and lwa=2 mtcrf 0x01,r20 // move DS field to cr7 rlwinm r3,r20,0,30,31 // must adjust EA by subtracting DS field sub r12,r12,r3 // subtract from full 64-bit EA and r17,r12,r15 // then re-clamp to 32 bits if necessary bt 30,a64Lwa // handle lwa crmove kUpdate,31 // if opcode bit 31 is set, it is ldu so set update flag a64Ldx: bl a64Load8Bytes // load 8 bytes from user space into r30 stdx r30,r14,r21 // update register file b a64UpdateCheck // update RA if necessary and exit // Store doubleword (stdx[u], std[u], stwcx) a64StdxStwcx: bf-- 30,a64PassAlong // stwcx, so pass along alignment exception b a64Stdx // was stdx a64StdStfiwx: // if DS form: 0=std, 1=stdu, 2-3=undefined bt 30,a64Stfiwx // handle stfiwx rlwinm r3,r20,0,30,31 // must adjust EA by subtracting DS field mtcrf 0x01,r20 // move DS field to cr7 sub r12,r12,r3 // subtract from full 64-bit EA and r17,r12,r15 // then re-clamp to 32 bits if necessary crmove kUpdate,31 // if DS==1, then it is update form a64Stdx: ldx r30,r14,r21 // get RT bl a64Store8Bytes // store RT into user space b a64UpdateCheck // update RA if necessary and exit // Dcbz and Dcbz128 (bit 10 distinguishes the two forms) a64DcbzDcbz128: andis. r0,r20,0x0020 // bit 10 set? li r3,0 // get a 0 to store li r0,4 // assume 32-bit version, store 8 bytes 4x rldicr r17,r17,0,63-5 // 32-byte align EA li r4,_COMM_PAGE_BASE_ADDRESS beq a64DcbzSetup // it was the 32-byte version rldicr r17,r17,0,63-7 // zero low 7 bits of EA li r0,16 // store 8 bytes 16x a64DcbzSetup: sub r4,r28,r4 // get instruction offset from start of commpage and r4,r4,r15 // mask off high-order bits if 32-bit mode cmpldi r4,_COMM_PAGE_AREA_USED // did fault occur in commpage area? bge a64NotCommpage // not in commpage rlwinm. r4,r29,0,MSR_PR_BIT,MSR_PR_BIT // did fault occur in user mode? beq-- a64NotCommpage // do not zero cr7 if kernel got alignment exception lwz r4,savecr(r13) // if we take a dcbz{128} in the commpage... rlwinm r4,r4,0,0,27 // ...clear user's cr7... stw r4,savecr(r13) // ...as a flag for commpage code a64NotCommpage: mtctr r0 cmpw r0,r0 // turn cr0 beq on so we can check for DSIs mtmsr r25 // turn on DR and RI so we can address user space isync // wait for it to happen a64DcbzLoop: std r3,0(r17) // store into user space bne-- a64RedriveAsDSI addi r17,r17,8 bdnz a64DcbzLoop mtmsr r26 // restore MSR isync // wait for it to happen b a64Exit // Load and store multiple (lmw, stmw), distinguished by bit 25 a64LmwStmw: subfic r22,r21,32*8 // how many regs to load or store? srwi r22,r22,1 // get bytes to load/store bf 25,a64LoadMultiple // handle lmw b a64StoreMultiple // it was stmw // Load string word immediate (lswi) a64Lswi: rlwinm r22,r20,21,27,31 // get #bytes in r22 and r17,r18,r15 // recompute EA as (RA|0), and clamp subi r3,r22,1 // r22==0? rlwimi r22,r3,6,26,26 // map count of 0 to 32 b a64LoadMultiple // Store string word immediate (stswi) a64Stswi: rlwinm r22,r20,21,27,31 // get #bytes in r22 and r17,r18,r15 // recompute EA as (RA|0), and clamp subi r3,r22,1 // r22==0? rlwimi r22,r3,6,26,26 // map count of 0 to 32 b a64StoreMultiple // Load string word indexed (lswx), also lwbrx a64LswxLwbrx: bf 30,a64Lwbrx // was lwbrx ld r22,savexer(r13) // get the xer rlwinm r22,r22,0,25,31 // isolate the byte count b a64LoadMultiple // join common code // Store string word indexed (stswx), also stwbrx a64StswxStwbrx: bf 30,a64Stwbrx // was stwbrx ld r22,savexer(r13) // get the xer rlwinm r22,r22,0,25,31 // isolate the byte count b a64StoreMultiple // join common code // Load multiple words. This handles lmw, lswi, and lswx. a64LoadMultiple: // r22 = byte count, may be 0 subic. r3,r22,1 // get (#bytes-1) blt a64Exit // done if 0 add r4,r17,r3 // get EA of last operand byte and r4,r4,r15 // clamp cmpld r4,r17 // address space wrap? blt-- a64PassAlong // pass along exception if so srwi. r4,r22,2 // get # full words to load rlwinm r22,r22,0,30,31 // r22 <- leftover byte count cmpwi cr1,r22,0 // leftover bytes? beq a64Lm3 // no words mtctr r4 // set up word count cmpw r0,r0 // set beq for DSI test a64Lm2: mtmsr r25 // turn on DR and RI isync // wait for it to happen lbz r3,0(r17) bne-- a64RedriveAsDSI // got a DSI lbz r4,1(r17) bne-- a64RedriveAsDSI // got a DSI lbz r5,2(r17) bne-- a64RedriveAsDSI // got a DSI lbz r6,3(r17) bne-- a64RedriveAsDSI // got a DSI rlwinm r30,r3,24,0,7 // pack bytes into r30 rldimi r30,r4,16,40 rldimi r30,r5,8,48 rldimi r30,r6,0,56 mtmsr r26 // turn DR back off so we can store into register file isync addi r17,r17,4 // bump EA stdx r30,r14,r21 // pack into register file addi r21,r21,8 // bump register file offset rlwinm r21,r21,0,24,28 // wrap around to 0 bdnz a64Lm2 a64Lm3: // cr1/r22 = leftover bytes (0-3), cr0 beq set beq cr1,a64Exit // no leftover bytes mtctr r22 mtmsr r25 // turn on DR so we can access user space isync lbz r3,0(r17) // get 1st leftover byte bne-- a64RedriveAsDSI // got a DSI rlwinm r30,r3,24,0,7 // position in byte 4 of r30 (and clear rest of r30) bdz a64Lm4 // only 1 byte leftover lbz r3,1(r17) // get 2nd byte bne-- a64RedriveAsDSI // got a DSI rldimi r30,r3,16,40 // insert into byte 5 of r30 bdz a64Lm4 // only 2 bytes leftover lbz r3,2(r17) // get 3rd byte bne-- a64RedriveAsDSI // got a DSI rldimi r30,r3,8,48 // insert into byte 6 a64Lm4: mtmsr r26 // turn DR back off so we can store into register file isync stdx r30,r14,r21 // pack partially-filled word into register file b a64Exit // Store multiple words. This handles stmw, stswi, and stswx. a64StoreMultiple: // r22 = byte count, may be 0 subic. r3,r22,1 // get (#bytes-1) blt a64Exit // done if 0 add r4,r17,r3 // get EA of last operand byte and r4,r4,r15 // clamp cmpld r4,r17 // address space wrap? blt-- a64PassAlong // pass along exception if so srwi. r4,r22,2 // get # full words to load rlwinm r22,r22,0,30,31 // r22 <- leftover byte count cmpwi cr1,r22,0 // leftover bytes? beq a64Sm3 // no words mtctr r4 // set up word count cmpw r0,r0 // turn on beq so we can check for DSIs a64Sm2: ldx r30,r14,r21 // get next register addi r21,r21,8 // bump register file offset rlwinm r21,r21,0,24,28 // wrap around to 0 srwi r3,r30,24 // shift the four bytes into position srwi r4,r30,16 srwi r5,r30,8 mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen stb r3,0(r17) bne-- a64RedriveAsDSI // got a DSI stb r4,1(r17) bne-- a64RedriveAsDSI // got a DSI stb r5,2(r17) bne-- a64RedriveAsDSI // got a DSI stb r30,3(r17) bne-- a64RedriveAsDSI // got a DSI mtmsr r26 // turn DR back off isync addi r17,r17,4 // bump EA bdnz a64Sm2 a64Sm3: // r22 = 0-3, cr1 set on r22, cr0 beq set beq cr1,a64Exit // no leftover bytes ldx r30,r14,r21 // get last register mtctr r22 mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen a64Sm4: rlwinm r30,r30,8,0,31 // position next byte stb r30,0(r17) // pack into user space addi r17,r17,1 // bump user space ptr bne-- a64RedriveAsDSI // got a DSI bdnz a64Sm4 mtmsr r26 // turn DR back off isync b a64Exit // Subroutines to load bytes from user space. a64Load2Bytes: // load 2 bytes right-justified into r30 addi r7,r17,1 // get EA of last byte and r7,r7,r15 // clamp cmpld r7,r17 // address wrap? blt-- a64PassAlong // yes mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen sub. r30,r30,r30 // 0-fill dest and set beq b a64Load2 // jump into routine a64Load4Bytes: // load 4 bytes right-justified into r30 (ie, low order word) addi r7,r17,3 // get EA of last byte and r7,r7,r15 // clamp cmpld r7,r17 // address wrap? blt-- a64PassAlong // yes mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen sub. r30,r30,r30 // 0-fill dest and set beq b a64Load4 // jump into routine a64Load8Bytes: // load 8 bytes into r30 addi r7,r17,7 // get EA of last byte and r7,r7,r15 // clamp cmpld r7,r17 // address wrap? blt-- a64PassAlong // yes mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen sub. r30,r30,r30 // 0-fill dest and set beq lbz r3,-7(r7) // get byte 0 bne-- a64RedriveAsDSI // got a DSI lbz r4,-6(r7) // and byte 1, etc bne-- a64RedriveAsDSI // got a DSI lbz r5,-5(r7) bne-- a64RedriveAsDSI // got a DSI lbz r6,-4(r7) bne-- a64RedriveAsDSI // got a DSI rldimi r30,r3,56,0 // position bytes in upper word rldimi r30,r4,48,8 rldimi r30,r5,40,16 rldimi r30,r6,32,24 a64Load4: lbz r3,-3(r7) bne-- a64RedriveAsDSI // got a DSI lbz r4,-2(r7) bne-- a64RedriveAsDSI // got a DSI rldimi r30,r3,24,32 // insert bytes 4 and 5 into r30 rldimi r30,r4,16,40 a64Load2: lbz r3,-1(r7) bne-- a64RedriveAsDSI // got a DSI lbz r4,0(r7) bne-- a64RedriveAsDSI // got a DSI mtmsr r26 // turn DR back off isync rldimi r30,r3,8,48 // insert bytes 6 and 7 into r30 rldimi r30,r4,0,56 blr // Subroutines to store bytes into user space. a64Store2Bytes: // store bytes 6 and 7 of r30 addi r7,r17,1 // get EA of last byte and r7,r7,r15 // clamp cmpld r7,r17 // address wrap? blt-- a64PassAlong // yes mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen cmpw r0,r0 // set beq so we can check for DSI b a64Store2 // jump into routine a64Store4Bytes: // store bytes 4-7 of r30 (ie, low order word) addi r7,r17,3 // get EA of last byte and r7,r7,r15 // clamp cmpld r7,r17 // address wrap? blt-- a64PassAlong // yes mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen cmpw r0,r0 // set beq so we can check for DSI b a64Store4 // jump into routine a64Store8Bytes: // r30 = bytes addi r7,r17,7 // get EA of last byte and r7,r7,r15 // clamp cmpld r7,r17 // address wrap? blt-- a64PassAlong // yes mtmsr r25 // turn on DR so we can access user space isync // wait for it to happen cmpw r0,r0 // set beq so we can check for DSI rotldi r3,r30,8 // shift byte 0 into position rotldi r4,r30,16 // and byte 1 rotldi r5,r30,24 // and byte 2 rotldi r6,r30,32 // and byte 3 stb r3,-7(r7) // store byte 0 bne-- a64RedriveAsDSI // got a DSI stb r4,-6(r7) // and byte 1 etc... bne-- a64RedriveAsDSI // got a DSI stb r5,-5(r7) bne-- a64RedriveAsDSI // got a DSI stb r6,-4(r7) bne-- a64RedriveAsDSI // got a DSI a64Store4: rotldi r3,r30,40 // shift byte 4 into position rotldi r4,r30,48 // and byte 5 stb r3,-3(r7) bne-- a64RedriveAsDSI // got a DSI stb r4,-2(r7) bne-- a64RedriveAsDSI // got a DSI a64Store2: rotldi r3,r30,56 // shift byte 6 into position stb r3,-1(r7) // store byte 6 bne-- a64RedriveAsDSI // got a DSI stb r30,0(r7) // store byte 7, which is already positioned bne-- a64RedriveAsDSI // got a DSI mtmsr r26 // turn off DR isync blr // Exit routines. a64ExitEm: li r30,T_EMULATE // Change exception code to emulate stw r30,saveexception(r13) // Save it b a64Exit // Join standard exit routine... a64PassAlong: // unhandled exception, just pass it along li r0,1 // Set that the alignment/program exception was not emulated crset kNotify // return T_ALIGNMENT or T_PROGRAM stw r0,savemisc3(r13) // Set that emulation was not done crclr kTrace // not a trace interrupt b a64Exit1 a64UpdateCheck: // successfully emulated, may be update form bf kUpdate,a64Exit // update? stdx r12,r14,r16 // yes, store 64-bit EA into RA a64Exit: // instruction successfully emulated addi r28,r28,4 // bump SRR0 past the emulated instruction li r30,T_IN_VAIN // eat the interrupt since we emulated it and r28,r28,r15 // clamp to address space size (32 vs 64) std r28,savesrr0(r13) // save, so we return to next instruction a64Exit1: bt-- kTrace,a64Trace // were we in single-step at fault? bt-- kNotify,a64Notify // should we say T_ALIGNMENT anyway? a64Exit2: mcrf cr6,cr3 // restore feature flags mr r11,r30 // pass back exception code (T_IN_VAIN etc) in r11 b EXT(EmulExit) // return to exception processing // Notification requested: pass exception upstairs even though it might have been emulated. a64Notify: li r30,T_ALIGNMENT // somebody wants to know about it (but don't redrive) bt kAlignment,a64Exit2 // was an alignment exception li r30,T_PROGRAM // was an emulated instruction b a64Exit2 // Emulate a trace interrupt after handling alignment interrupt. a64Trace: lwz r9,SAVflags(r13) // get the save-area flags li r30,T_TRACE oris r9,r9,hi16(SAVredrive) // Set the redrive bit stw r30,saveexception(r13) // Set the exception code stw r9,SAVflags(r13) // Set the flags b a64Exit2 // Exit and do trace interrupt... // Got a DSI accessing user space. Redrive. One way this can happen is if another // processor removes a mapping while we are emulating. a64RedriveAsISI: // this DSI happened fetching the opcode (r1==DSISR r4==DAR) mtmsr r26 // turn DR back off isync // wait for it to happen li r30,T_INSTRUCTION_ACCESS rlwimi r29,r1,0,0,4 // insert the fault type from DSI's DSISR std r29,savesrr1(r13) // update SRR1 to look like an ISI b a64Redrive a64RedriveAsDSI: // r0==DAR r1==DSISR mtmsr r26 // turn DR back off isync // wait for it to happen stw r1,savedsisr(r13) // Set the DSISR of failed access std r0,savedar(r13) // Set the address of the failed access li r30,T_DATA_ACCESS // Set failing data access code a64Redrive: lwz r9,SAVflags(r13) // Pick up the flags stw r30,saveexception(r13) // Set the replacement code oris r9,r9,hi16(SAVredrive) // Set the redrive bit stw r9,SAVflags(r13) // Set redrive request crclr kTrace // don't take a trace interrupt crclr kNotify // don't pass alignment exception b a64Exit2 // done // This is the branch table, indexed by the "AAAAB" opcode hash. a64BranchTable: .long a64LwzLwzxLwarx // 00000 lwz[u], lwzx[u], lwarx .long a64Ldx // 00001 ldx[u] .long a64PassAlong // 00010 ldarx (never emulate these) .long a64PassAlong // 00011 .long a64StwStwx // 00100 stw[u], stwx[u] .long a64StdxStwcx // 00101 stdx[u], stwcx .long a64PassAlong // 00110 .long a64PassAlong // 00111 stdcx (never emulate these) .long a64LhzLhzx // 01000 lhz[u], lhzx[u] .long a64PassAlong // 01001 .long a64LhaLhax // 01010 lha[u], lhax[u] .long a64Lwax // 01011 lwax[u] .long a64SthSthx // 01100 sth[u], sthx[u] .long a64PassAlong // 01101 .long a64LmwStmw // 01110 lmw, stmw .long a64PassAlong // 01111 .long a64LfsLfsx // 10000 lfs[u], lfsx[u] .long a64LswxLwbrx // 10001 lswx, lwbrx .long a64LfdLfdx // 10010 lfd[u], lfdx[u] .long a64Lswi // 10011 lswi .long a64StfsStfsx // 10100 stfs[u], stfsx[u] .long a64StswxStwbrx // 10101 stswx, stwbrx .long a64StfdStfdx // 10110 stfd[u], stfdx[u] .long a64Stswi // 10111 stswi .long a64PassAlong // 11000 .long a64Lhbrx // 11001 lhbrx .long a64LdLwa // 11010 ld[u], lwa .long a64PassAlong // 11011 .long a64PassAlong // 11100 .long a64Sthbrx // 11101 sthbrx .long a64StdStfiwx // 11110 std[u], stfiwx .long a64DcbzDcbz128 // 11111 dcbz, dcbz128