diff options
| -rw-r--r-- | arch/powerpc/kernel/head_8xx.S | 147 |
1 files changed, 143 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index a9f1ace..c00120d 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -494,11 +494,16 @@ DataTLBError: mfspr r10, SPRN_DAR cmpwi cr0, r10, 0x00f0 - beq- 2f /* must be a buggy dcbX, icbi insn. */ - + beq- FixupDAR /* must be a buggy dcbX, icbi insn. */ +DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR */ mfspr r11, SPRN_DSISR - andis. r11, r11, 0x4800 /* !translation or protection */ - bne 2f /* branch if either is set */ + /* As the DAR fixup may clear store we may have all 3 states zero. + * Make sure only 0x0200(store) falls down into DIRTY handling + */ + andis. r11, r11, 0x4a00 /* !translation, protection or store */ + srwi r11, r11, 16 + cmpwi cr0, r11, 0x0200 /* just store ? */ + bne 2f /* Only Change bit left now, do it here as it is faster * than trapping to the C fault handler. */ @@ -604,6 +609,140 @@ DataTLBError: . = 0x2000 +/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions + * by decoding the registers used by the dcbx instruction and adding them. + * DAR is set to the calculated address and r10 also holds the EA on exit. + */ + /* define if you don't want to use self modifying code */ +#define NO_SELF_MODIFYING_CODE +FixupDAR:/* Entry point for dcbx workaround. */ + /* fetch instruction from memory. */ + mfspr r10, SPRN_SRR0 + DO_8xx_CPU6(0x3780, r3) + mtspr SPRN_MD_EPN, r10 + mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */ + cmplwi cr0, r11, 0x0800 + blt- 3f /* Branch if user space */ + lis r11, (swapper_pg_dir-PAGE_OFFSET)@h + ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l + rlwimi r11, r10, 32-20, 0xffc /* r11 = r11&~0xffc|(r10>>20)&0xffc */ +3: lwz r11, 0(r11) /* Get the level 1 entry */ + DO_8xx_CPU6(0x3b80, r3) + mtspr SPRN_MD_TWC, r11 /* Load pte table base address */ + mfspr r11, SPRN_MD_TWC /* ....and get the pte address */ + lwz r11, 0(r11) /* Get the pte */ + /* concat physical page address(r11) and page offset(r10) */ + rlwimi r11, r10, 0, 20, 31 + lwz r11,0(r11) +/* Check if it really is a dcbx instruction. */ +/* dcbt and dcbtst does not generate DTLB Misses/Errors, + * no need to include them here */ + srwi r10, r11, 26 /* check if major OP code is 31 */ + cmpwi cr0, r10, 31 + bne- 141f + rlwinm r10, r11, 0, 21, 30 + cmpwi cr0, r10, 2028 /* Is dcbz? */ + beq+ 142f + cmpwi cr0, r10, 940 /* Is dcbi? */ + beq+ 142f + cmpwi cr0, r10, 108 /* Is dcbst? */ + beq+ 144f /* Fix up store bit! */ + cmpwi cr0, r10, 172 /* Is dcbf? */ + beq+ 142f + cmpwi cr0, r10, 1964 /* Is icbi? */ + beq+ 142f +141: mfspr r10, SPRN_DAR /* r10 must hold DAR at exit */ + b DARFixed /* Nope, go back to normal TLB processing */ + +144: mfspr r10, SPRN_DSISR + rlwinm r10, r10,0,7,5 /* Clear store bit for buggy dcbst insn */ + mtspr SPRN_DSISR, r10 +142: /* continue, it was a dcbx, dcbi instruction. */ +#ifdef CONFIG_8xx_CPU6 + lwz r3, 8(r0) /* restore r3 from memory */ +#endif +#ifndef NO_SELF_MODIFYING_CODE + andis. r10,r11,0x1f /* test if reg RA is r0 */ + li r10,modified_instr@l + dcbtst r0,r10 /* touch for store */ + rlwinm r11,r11,0,0,20 /* Zero lower 10 bits */ + oris r11,r11,640 /* Transform instr. to a "add r10,RA,RB" */ + ori r11,r11,532 + stw r11,0(r10) /* store add/and instruction */ + dcbf 0,r10 /* flush new instr. to memory. */ + icbi 0,r10 /* invalidate instr. cache line */ + lwz r11, 4(r0) /* restore r11 from memory */ + mfspr r10, SPRN_M_TW /* restore r10 from M_TW */ + isync /* Wait until new instr is loaded from memory */ +modified_instr: + .space 4 /* this is where the add instr. is stored */ + bne+ 143f + subf r10,r0,r10 /* r10=r10-r0, only if reg RA is r0 */ +143: mtdar r10 /* store faulting EA in DAR */ + b DARFixed /* Go back to normal TLB handling */ +#else + mfctr r10 + mtdar r10 /* save ctr reg in DAR */ + rlwinm r10, r11, 24, 24, 28 /* offset into jump table for reg RB */ + addi r10, r10, 150f@l /* add start of table */ + mtctr r10 /* load ctr with jump address */ + xor r10, r10, r10 /* sum starts at zero */ + bctr /* jump into table */ +150: + add r10, r10, r0 ;b 151f + add r10, r10, r1 ;b 151f + add r10, r10, r2 ;b 151f + add r10, r10, r3 ;b 151f + add r10, r10, r4 ;b 151f + add r10, r10, r5 ;b 151f + add r10, r10, r6 ;b 151f + add r10, r10, r7 ;b 151f + add r10, r10, r8 ;b 151f + add r10, r10, r9 ;b 151f + mtctr r11 ;b 154f /* r10 needs special handling */ + mtctr r11 ;b 153f /* r11 needs special handling */ + add r10, r10, r12 ;b 151f + add r10, r10, r13 ;b 151f + add r10, r10, r14 ;b 151f + add r10, r10, r15 ;b 151f + add r10, r10, r16 ;b 151f + add r10, r10, r17 ;b 151f + add r10, r10, r18 ;b 151f + add r10, r10, r19 ;b 151f + add r10, r10, r20 ;b 151f + add r10, r10, r21 ;b 151f + add r10, r10, r22 ;b 151f + add r10, r10, r23 ;b 151f + add r10, r10, r24 ;b 151f + add r10, r10, r25 ;b 151f + add r10, r10, r26 ;b 151f + add r10, r10, r27 ;b 151f + add r10, r10, r28 ;b 151f + add r10, r10, r29 ;b 151f + add r10, r10, r30 ;b 151f + add r10, r10, r31 +151: + rlwinm. r11,r11,19,24,28 /* offset into jump table for reg RA */ + beq 152f /* if reg RA is zero, don't add it */ + addi r11, r11, 150b@l /* add start of table */ + mtctr r11 /* load ctr with jump address */ + rlwinm r11,r11,0,16,10 /* make sure we don't execute this more than once */ + bctr /* jump into table */ +152: + mfdar r11 + mtctr r11 /* restore ctr reg from DAR */ + mtdar r10 /* save fault EA to DAR */ + b DARFixed /* Go back to normal TLB handling */ + + /* special handling for r10,r11 since these are modified already */ +153: lwz r11, 4(r0) /* load r11 from memory */ + b 155f +154: mfspr r11, SPRN_M_TW /* load r10 from M_TW */ +155: add r10, r10, r11 /* add it */ + mfctr r11 /* restore r11 */ + b 151b +#endif + .globl giveup_fpu giveup_fpu: blr |