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Diffstat (limited to 'arch/m68k/fpsp040/bugfix.S')
| -rw-r--r-- | arch/m68k/fpsp040/bugfix.S | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/arch/m68k/fpsp040/bugfix.S b/arch/m68k/fpsp040/bugfix.S new file mode 100644 index 000000000..3bb9c84bb --- /dev/null +++ b/arch/m68k/fpsp040/bugfix.S @@ -0,0 +1,495 @@ +| +| bugfix.sa 3.2 1/31/91 +| +| +| This file contains workarounds for bugs in the 040 +| relating to the Floating-Point Software Package (FPSP) +| +| Fixes for bugs: 1238 +| +| Bug: 1238 +| +| +| /* The following dirty_bit clear should be left in +| * the handler permanently to improve throughput. +| * The dirty_bits are located at bits [23:16] in +| * longword $08 in the busy frame $4x60. Bit 16 +| * corresponds to FP0, bit 17 corresponds to FP1, +| * and so on. +| */ +| if (E3_exception_just_serviced) { +| dirty_bit[cmdreg3b[9:7]] = 0; +| } +| +| if (fsave_format_version != $40) {goto NOFIX} +| +| if !(E3_exception_just_serviced) {goto NOFIX} +| if (cupc == 0000000) {goto NOFIX} +| if ((cmdreg1b[15:13] != 000) && +| (cmdreg1b[15:10] != 010001)) {goto NOFIX} +| if (((cmdreg1b[15:13] != 000) || ((cmdreg1b[12:10] != cmdreg2b[9:7]) && +| (cmdreg1b[12:10] != cmdreg3b[9:7])) ) && +| ((cmdreg1b[ 9: 7] != cmdreg2b[9:7]) && +| (cmdreg1b[ 9: 7] != cmdreg3b[9:7])) ) {goto NOFIX} +| +| /* Note: for 6d43b or 8d43b, you may want to add the following code +| * to get better coverage. (If you do not insert this code, the part +| * won't lock up; it will simply get the wrong answer.) +| * Do NOT insert this code for 10d43b or later parts. +| * +| * if (fpiarcu == integer stack return address) { +| * cupc = 0000000; +| * goto NOFIX; +| * } +| */ +| +| if (cmdreg1b[15:13] != 000) {goto FIX_OPCLASS2} +| FIX_OPCLASS0: +| if (((cmdreg1b[12:10] == cmdreg2b[9:7]) || +| (cmdreg1b[ 9: 7] == cmdreg2b[9:7])) && +| (cmdreg1b[12:10] != cmdreg3b[9:7]) && +| (cmdreg1b[ 9: 7] != cmdreg3b[9:7])) { /* xu conflict only */ +| /* We execute the following code if there is an +| xu conflict and NOT an nu conflict */ +| +| /* first save some values on the fsave frame */ +| stag_temp = STAG[fsave_frame]; +| cmdreg1b_temp = CMDREG1B[fsave_frame]; +| dtag_temp = DTAG[fsave_frame]; +| ete15_temp = ETE15[fsave_frame]; +| +| CUPC[fsave_frame] = 0000000; +| FRESTORE +| FSAVE +| +| /* If the xu instruction is exceptional, we punt. +| * Otherwise, we would have to include OVFL/UNFL handler +| * code here to get the correct answer. +| */ +| if (fsave_frame_format == $4060) {goto KILL_PROCESS} +| +| fsave_frame = /* build a long frame of all zeros */ +| fsave_frame_format = $4060; /* label it as long frame */ +| +| /* load it with the temps we saved */ +| STAG[fsave_frame] = stag_temp; +| CMDREG1B[fsave_frame] = cmdreg1b_temp; +| DTAG[fsave_frame] = dtag_temp; +| ETE15[fsave_frame] = ete15_temp; +| +| /* Make sure that the cmdreg3b dest reg is not going to +| * be destroyed by a FMOVEM at the end of all this code. +| * If it is, you should move the current value of the reg +| * onto the stack so that the reg will loaded with that value. +| */ +| +| /* All done. Proceed with the code below */ +| } +| +| etemp = FP_reg_[cmdreg1b[12:10]]; +| ete15 = ~ete14; +| cmdreg1b[15:10] = 010010; +| clear(bug_flag_procIDxxxx); +| FRESTORE and return; +| +| +| FIX_OPCLASS2: +| if ((cmdreg1b[9:7] == cmdreg2b[9:7]) && +| (cmdreg1b[9:7] != cmdreg3b[9:7])) { /* xu conflict only */ +| /* We execute the following code if there is an +| xu conflict and NOT an nu conflict */ +| +| /* first save some values on the fsave frame */ +| stag_temp = STAG[fsave_frame]; +| cmdreg1b_temp = CMDREG1B[fsave_frame]; +| dtag_temp = DTAG[fsave_frame]; +| ete15_temp = ETE15[fsave_frame]; +| etemp_temp = ETEMP[fsave_frame]; +| +| CUPC[fsave_frame] = 0000000; +| FRESTORE +| FSAVE +| +| +| /* If the xu instruction is exceptional, we punt. +| * Otherwise, we would have to include OVFL/UNFL handler +| * code here to get the correct answer. +| */ +| if (fsave_frame_format == $4060) {goto KILL_PROCESS} +| +| fsave_frame = /* build a long frame of all zeros */ +| fsave_frame_format = $4060; /* label it as long frame */ +| +| /* load it with the temps we saved */ +| STAG[fsave_frame] = stag_temp; +| CMDREG1B[fsave_frame] = cmdreg1b_temp; +| DTAG[fsave_frame] = dtag_temp; +| ETE15[fsave_frame] = ete15_temp; +| ETEMP[fsave_frame] = etemp_temp; +| +| /* Make sure that the cmdreg3b dest reg is not going to +| * be destroyed by a FMOVEM at the end of all this code. +| * If it is, you should move the current value of the reg +| * onto the stack so that the reg will loaded with that value. +| */ +| +| /* All done. Proceed with the code below */ +| } +| +| if (etemp_exponent == min_sgl) etemp_exponent = min_dbl; +| if (etemp_exponent == max_sgl) etemp_exponent = max_dbl; +| cmdreg1b[15:10] = 010101; +| clear(bug_flag_procIDxxxx); +| FRESTORE and return; +| +| +| NOFIX: +| clear(bug_flag_procIDxxxx); +| FRESTORE and return; +| + + +| Copyright (C) Motorola, Inc. 1990 +| All Rights Reserved +| +| For details on the license for this file, please see the +| file, README, in this same directory. + +|BUGFIX idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + +#include "fpsp.h" + + |xref fpsp_fmt_error + + .global b1238_fix +b1238_fix: +| +| This code is entered only on completion of the handling of an +| nu-generated ovfl, unfl, or inex exception. If the version +| number of the fsave is not $40, this handler is not necessary. +| Simply branch to fix_done and exit normally. +| + cmpib #VER_40,4(%a7) + bne fix_done +| +| Test for cu_savepc equal to zero. If not, this is not a bug +| #1238 case. +| + moveb CU_SAVEPC(%a6),%d0 + andib #0xFE,%d0 + beq fix_done |if zero, this is not bug #1238 + +| +| Test the register conflict aspect. If opclass0, check for +| cu src equal to xu dest or equal to nu dest. If so, go to +| op0. Else, or if opclass2, check for cu dest equal to +| xu dest or equal to nu dest. If so, go to tst_opcl. Else, +| exit, it is not the bug case. +| +| Check for opclass 0. If not, go and check for opclass 2 and sgl. +| + movew CMDREG1B(%a6),%d0 + andiw #0xE000,%d0 |strip all but opclass + bne op2sgl |not opclass 0, check op2 +| +| Check for cu and nu register conflict. If one exists, this takes +| priority over a cu and xu conflict. +| + bfextu CMDREG1B(%a6){#3:#3},%d0 |get 1st src + bfextu CMDREG3B(%a6){#6:#3},%d1 |get 3rd dest + cmpb %d0,%d1 + beqs op0 |if equal, continue bugfix +| +| Check for cu dest equal to nu dest. If so, go and fix the +| bug condition. Otherwise, exit. +| + bfextu CMDREG1B(%a6){#6:#3},%d0 |get 1st dest + cmpb %d0,%d1 |cmp 1st dest with 3rd dest + beqs op0 |if equal, continue bugfix +| +| Check for cu and xu register conflict. +| + bfextu CMDREG2B(%a6){#6:#3},%d1 |get 2nd dest + cmpb %d0,%d1 |cmp 1st dest with 2nd dest + beqs op0_xu |if equal, continue bugfix + bfextu CMDREG1B(%a6){#3:#3},%d0 |get 1st src + cmpb %d0,%d1 |cmp 1st src with 2nd dest + beq op0_xu + bne fix_done |if the reg checks fail, exit +| +| We have the opclass 0 situation. +| +op0: + bfextu CMDREG1B(%a6){#3:#3},%d0 |get source register no + movel #7,%d1 + subl %d0,%d1 + clrl %d0 + bsetl %d1,%d0 + fmovemx %d0,ETEMP(%a6) |load source to ETEMP + + moveb #0x12,%d0 + bfins %d0,CMDREG1B(%a6){#0:#6} |opclass 2, extended +| +| Set ETEMP exponent bit 15 as the opposite of ete14 +| + btst #6,ETEMP_EX(%a6) |check etemp exponent bit 14 + beq setete15 + bclr #etemp15_bit,STAG(%a6) + bra finish +setete15: + bset #etemp15_bit,STAG(%a6) + bra finish + +| +| We have the case in which a conflict exists between the cu src or +| dest and the dest of the xu. We must clear the instruction in +| the cu and restore the state, allowing the instruction in the +| xu to complete. Remember, the instruction in the nu +| was exceptional, and was completed by the appropriate handler. +| If the result of the xu instruction is not exceptional, we can +| restore the instruction from the cu to the frame and continue +| processing the original exception. If the result is also +| exceptional, we choose to kill the process. +| +| Items saved from the stack: +| +| $3c stag - L_SCR1 +| $40 cmdreg1b - L_SCR2 +| $44 dtag - L_SCR3 +| +| The cu savepc is set to zero, and the frame is restored to the +| fpu. +| +op0_xu: + movel STAG(%a6),L_SCR1(%a6) + movel CMDREG1B(%a6),L_SCR2(%a6) + movel DTAG(%a6),L_SCR3(%a6) + andil #0xe0000000,L_SCR3(%a6) + moveb #0,CU_SAVEPC(%a6) + movel (%a7)+,%d1 |save return address from bsr + frestore (%a7)+ + fsave -(%a7) +| +| Check if the instruction which just completed was exceptional. +| + cmpw #0x4060,(%a7) + beq op0_xb +| +| It is necessary to isolate the result of the instruction in the +| xu if it is to fp0 - fp3 and write that value to the USER_FPn +| locations on the stack. The correct destination register is in +| cmdreg2b. +| + bfextu CMDREG2B(%a6){#6:#3},%d0 |get dest register no + cmpil #3,%d0 + bgts op0_xi + beqs op0_fp3 + cmpil #1,%d0 + blts op0_fp0 + beqs op0_fp1 +op0_fp2: + fmovemx %fp2-%fp2,USER_FP2(%a6) + bras op0_xi +op0_fp1: + fmovemx %fp1-%fp1,USER_FP1(%a6) + bras op0_xi +op0_fp0: + fmovemx %fp0-%fp0,USER_FP0(%a6) + bras op0_xi +op0_fp3: + fmovemx %fp3-%fp3,USER_FP3(%a6) +| +| The frame returned is idle. We must build a busy frame to hold +| the cu state information and setup etemp. +| +op0_xi: + movel #22,%d0 |clear 23 lwords + clrl (%a7) +op0_loop: + clrl -(%a7) + dbf %d0,op0_loop + movel #0x40600000,-(%a7) + movel L_SCR1(%a6),STAG(%a6) + movel L_SCR2(%a6),CMDREG1B(%a6) + movel L_SCR3(%a6),DTAG(%a6) + moveb #0x6,CU_SAVEPC(%a6) + movel %d1,-(%a7) |return bsr return address + bfextu CMDREG1B(%a6){#3:#3},%d0 |get source register no + movel #7,%d1 + subl %d0,%d1 + clrl %d0 + bsetl %d1,%d0 + fmovemx %d0,ETEMP(%a6) |load source to ETEMP + + moveb #0x12,%d0 + bfins %d0,CMDREG1B(%a6){#0:#6} |opclass 2, extended +| +| Set ETEMP exponent bit 15 as the opposite of ete14 +| + btst #6,ETEMP_EX(%a6) |check etemp exponent bit 14 + beq op0_sete15 + bclr #etemp15_bit,STAG(%a6) + bra finish +op0_sete15: + bset #etemp15_bit,STAG(%a6) + bra finish + +| +| The frame returned is busy. It is not possible to reconstruct +| the code sequence to allow completion. We will jump to +| fpsp_fmt_error and allow the kernel to kill the process. +| +op0_xb: + jmp fpsp_fmt_error + +| +| Check for opclass 2 and single size. If not both, exit. +| +op2sgl: + movew CMDREG1B(%a6),%d0 + andiw #0xFC00,%d0 |strip all but opclass and size + cmpiw #0x4400,%d0 |test for opclass 2 and size=sgl + bne fix_done |if not, it is not bug 1238 +| +| Check for cu dest equal to nu dest or equal to xu dest, with +| a cu and nu conflict taking priority an nu conflict. If either, +| go and fix the bug condition. Otherwise, exit. +| + bfextu CMDREG1B(%a6){#6:#3},%d0 |get 1st dest + bfextu CMDREG3B(%a6){#6:#3},%d1 |get 3rd dest + cmpb %d0,%d1 |cmp 1st dest with 3rd dest + beq op2_com |if equal, continue bugfix + bfextu CMDREG2B(%a6){#6:#3},%d1 |get 2nd dest + cmpb %d0,%d1 |cmp 1st dest with 2nd dest + bne fix_done |if the reg checks fail, exit +| +| We have the case in which a conflict exists between the cu src or +| dest and the dest of the xu. We must clear the instruction in +| the cu and restore the state, allowing the instruction in the +| xu to complete. Remember, the instruction in the nu +| was exceptional, and was completed by the appropriate handler. +| If the result of the xu instruction is not exceptional, we can +| restore the instruction from the cu to the frame and continue +| processing the original exception. If the result is also +| exceptional, we choose to kill the process. +| +| Items saved from the stack: +| +| $3c stag - L_SCR1 +| $40 cmdreg1b - L_SCR2 +| $44 dtag - L_SCR3 +| etemp - FP_SCR2 +| +| The cu savepc is set to zero, and the frame is restored to the +| fpu. +| +op2_xu: + movel STAG(%a6),L_SCR1(%a6) + movel CMDREG1B(%a6),L_SCR2(%a6) + movel DTAG(%a6),L_SCR3(%a6) + andil #0xe0000000,L_SCR3(%a6) + moveb #0,CU_SAVEPC(%a6) + movel ETEMP(%a6),FP_SCR2(%a6) + movel ETEMP_HI(%a6),FP_SCR2+4(%a6) + movel ETEMP_LO(%a6),FP_SCR2+8(%a6) + movel (%a7)+,%d1 |save return address from bsr + frestore (%a7)+ + fsave -(%a7) +| +| Check if the instruction which just completed was exceptional. +| + cmpw #0x4060,(%a7) + beq op2_xb +| +| It is necessary to isolate the result of the instruction in the +| xu if it is to fp0 - fp3 and write that value to the USER_FPn +| locations on the stack. The correct destination register is in +| cmdreg2b. +| + bfextu CMDREG2B(%a6){#6:#3},%d0 |get dest register no + cmpil #3,%d0 + bgts op2_xi + beqs op2_fp3 + cmpil #1,%d0 + blts op2_fp0 + beqs op2_fp1 +op2_fp2: + fmovemx %fp2-%fp2,USER_FP2(%a6) + bras op2_xi +op2_fp1: + fmovemx %fp1-%fp1,USER_FP1(%a6) + bras op2_xi +op2_fp0: + fmovemx %fp0-%fp0,USER_FP0(%a6) + bras op2_xi +op2_fp3: + fmovemx %fp3-%fp3,USER_FP3(%a6) +| +| The frame returned is idle. We must build a busy frame to hold +| the cu state information and fix up etemp. +| +op2_xi: + movel #22,%d0 |clear 23 lwords + clrl (%a7) +op2_loop: + clrl -(%a7) + dbf %d0,op2_loop + movel #0x40600000,-(%a7) + movel L_SCR1(%a6),STAG(%a6) + movel L_SCR2(%a6),CMDREG1B(%a6) + movel L_SCR3(%a6),DTAG(%a6) + moveb #0x6,CU_SAVEPC(%a6) + movel FP_SCR2(%a6),ETEMP(%a6) + movel FP_SCR2+4(%a6),ETEMP_HI(%a6) + movel FP_SCR2+8(%a6),ETEMP_LO(%a6) + movel %d1,-(%a7) + bra op2_com + +| +| We have the opclass 2 single source situation. +| +op2_com: + moveb #0x15,%d0 + bfins %d0,CMDREG1B(%a6){#0:#6} |opclass 2, double + + cmpw #0x407F,ETEMP_EX(%a6) |single +max + bnes case2 + movew #0x43FF,ETEMP_EX(%a6) |to double +max + bra finish +case2: + cmpw #0xC07F,ETEMP_EX(%a6) |single -max + bnes case3 + movew #0xC3FF,ETEMP_EX(%a6) |to double -max + bra finish +case3: + cmpw #0x3F80,ETEMP_EX(%a6) |single +min + bnes case4 + movew #0x3C00,ETEMP_EX(%a6) |to double +min + bra finish +case4: + cmpw #0xBF80,ETEMP_EX(%a6) |single -min + bne fix_done + movew #0xBC00,ETEMP_EX(%a6) |to double -min + bra finish +| +| The frame returned is busy. It is not possible to reconstruct +| the code sequence to allow completion. fpsp_fmt_error causes +| an fline illegal instruction to be executed. +| +| You should replace the jump to fpsp_fmt_error with a jump +| to the entry point used to kill a process. +| +op2_xb: + jmp fpsp_fmt_error + +| +| Enter here if the case is not of the situations affected by +| bug #1238, or if the fix is completed, and exit. +| +finish: +fix_done: + rts + + |end |