diff options
Diffstat (limited to 'arch/powerpc/kernel/head_8xx.S')
| -rw-r--r-- | arch/powerpc/kernel/head_8xx.S | 321 |
1 files changed, 200 insertions, 121 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 6ded19d01891..3ef743fa5d7c 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -206,6 +206,8 @@ MachineCheck: EXCEPTION_PROLOG mfspr r4,SPRN_DAR stw r4,_DAR(r11) + li r5,0x00f0 + mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */ mfspr r5,SPRN_DSISR stw r5,_DSISR(r11) addi r3,r1,STACK_FRAME_OVERHEAD @@ -222,6 +224,8 @@ DataAccess: stw r10,_DSISR(r11) mr r5,r10 mfspr r4,SPRN_DAR + li r10,0x00f0 + mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */ EXC_XFER_EE_LITE(0x300, handle_page_fault) /* Instruction access exception. @@ -244,6 +248,8 @@ Alignment: EXCEPTION_PROLOG mfspr r4,SPRN_DAR stw r4,_DAR(r11) + li r5,0x00f0 + mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */ mfspr r5,SPRN_DSISR stw r5,_DSISR(r11) addi r3,r1,STACK_FRAME_OVERHEAD @@ -333,26 +339,20 @@ InstructionTLBMiss: mfspr r11, SPRN_MD_TWC /* ....and get the pte address */ lwz r10, 0(r11) /* Get the pte */ -#ifdef CONFIG_SWAP - /* do not set the _PAGE_ACCESSED bit of a non-present page */ - andi. r11, r10, _PAGE_PRESENT - beq 4f - ori r10, r10, _PAGE_ACCESSED - mfspr r11, SPRN_MD_TWC /* get the pte address again */ - stw r10, 0(r11) -4: -#else - ori r10, r10, _PAGE_ACCESSED - stw r10, 0(r11) -#endif + andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT + cmpwi cr0, r11, _PAGE_ACCESSED | _PAGE_PRESENT + bne- cr0, 2f + + /* Clear PP lsb, 0x400 */ + rlwinm r10, r10, 0, 22, 20 /* The Linux PTE won't go exactly into the MMU TLB. - * Software indicator bits 21, 22 and 28 must be clear. + * Software indicator bits 22 and 28 must be clear. * Software indicator bits 24, 25, 26, and 27 must be * set. All other Linux PTE bits control the behavior * of the MMU. */ -2: li r11, 0x00f0 + li r11, 0x00f0 rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */ DO_8xx_CPU6(0x2d80, r3) mtspr SPRN_MI_RPN, r10 /* Update TLB entry */ @@ -365,6 +365,22 @@ InstructionTLBMiss: lwz r3, 8(r0) #endif rfi +2: + mfspr r11, SPRN_SRR1 + /* clear all error bits as TLB Miss + * sets a few unconditionally + */ + rlwinm r11, r11, 0, 0xffff + mtspr SPRN_SRR1, r11 + + mfspr r10, SPRN_M_TW /* Restore registers */ + lwz r11, 0(r0) + mtcr r11 + lwz r11, 4(r0) +#ifdef CONFIG_8xx_CPU6 + lwz r3, 8(r0) +#endif + b InstructionAccess . = 0x1200 DataStoreTLBMiss: @@ -406,29 +422,45 @@ DataStoreTLBMiss: * above. */ rlwimi r11, r10, 0, 27, 27 + /* Insert the WriteThru flag into the TWC from the Linux PTE. + * It is bit 25 in the Linux PTE and bit 30 in the TWC + */ + rlwimi r11, r10, 32-5, 30, 30 DO_8xx_CPU6(0x3b80, r3) mtspr SPRN_MD_TWC, r11 -#ifdef CONFIG_SWAP - /* do not set the _PAGE_ACCESSED bit of a non-present page */ - andi. r11, r10, _PAGE_PRESENT - beq 4f - ori r10, r10, _PAGE_ACCESSED -4: - /* and update pte in table */ -#else - ori r10, r10, _PAGE_ACCESSED -#endif - mfspr r11, SPRN_MD_TWC /* get the pte address again */ - stw r10, 0(r11) + /* Both _PAGE_ACCESSED and _PAGE_PRESENT has to be set. + * We also need to know if the insn is a load/store, so: + * Clear _PAGE_PRESENT and load that which will + * trap into DTLB Error with store bit set accordinly. + */ + /* PRESENT=0x1, ACCESSED=0x20 + * r11 = ((r10 & PRESENT) & ((r10 & ACCESSED) >> 5)); + * r10 = (r10 & ~PRESENT) | r11; + */ + rlwinm r11, r10, 32-5, _PAGE_PRESENT + and r11, r11, r10 + rlwimi r10, r11, 0, _PAGE_PRESENT + + /* Honour kernel RO, User NA */ + /* 0x200 == Extended encoding, bit 22 */ + /* r11 = (r10 & _PAGE_USER) >> 2 */ + rlwinm r11, r10, 32-2, 0x200 + or r10, r11, r10 + /* r11 = (r10 & _PAGE_RW) >> 1 */ + rlwinm r11, r10, 32-1, 0x200 + or r10, r11, r10 + /* invert RW and 0x200 bits */ + xori r10, r10, _PAGE_RW | 0x200 /* The Linux PTE won't go exactly into the MMU TLB. - * Software indicator bits 21, 22 and 28 must be clear. + * Software indicator bits 22 and 28 must be clear. * Software indicator bits 24, 25, 26, and 27 must be * set. All other Linux PTE bits control the behavior * of the MMU. */ 2: li r11, 0x00f0 + mtspr SPRN_DAR,r11 /* Tag DAR */ rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */ DO_8xx_CPU6(0x3d80, r3) mtspr SPRN_MD_RPN, r10 /* Update TLB entry */ @@ -469,97 +501,10 @@ DataTLBError: stw r10, 0(r0) stw r11, 4(r0) - /* First, make sure this was a store operation. - */ - mfspr r10, SPRN_DSISR - andis. r11, r10, 0x0200 /* If set, indicates store op */ - beq 2f - - /* The EA of a data TLB miss is automatically stored in the MD_EPN - * register. The EA of a data TLB error is automatically stored in - * the DAR, but not the MD_EPN register. We must copy the 20 most - * significant bits of the EA from the DAR to MD_EPN before we - * start walking the page tables. We also need to copy the CASID - * value from the M_CASID register. - * Addendum: The EA of a data TLB error is _supposed_ to be stored - * in DAR, but it seems that this doesn't happen in some cases, such - * as when the error is due to a dcbi instruction to a page with a - * TLB that doesn't have the changed bit set. In such cases, there - * does not appear to be any way to recover the EA of the error - * since it is neither in DAR nor MD_EPN. As a workaround, the - * _PAGE_HWWRITE bit is set for all kernel data pages when the PTEs - * are initialized in mapin_ram(). This will avoid the problem, - * assuming we only use the dcbi instruction on kernel addresses. - */ mfspr r10, SPRN_DAR - rlwinm r11, r10, 0, 0, 19 - ori r11, r11, MD_EVALID - mfspr r10, SPRN_M_CASID - rlwimi r11, r10, 0, 28, 31 - DO_8xx_CPU6(0x3780, r3) - mtspr SPRN_MD_EPN, r11 - - mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */ - - /* If we are faulting a kernel address, we have to use the - * kernel page tables. - */ - andi. r11, r10, 0x0800 - beq 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - rlwimi r10, r11, 0, 2, 19 -3: - lwz r11, 0(r10) /* Get the level 1 entry */ - rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */ - beq 2f /* If zero, bail */ - - /* We have a pte table, so fetch the pte from the table. - */ - ori r11, r11, 1 /* Set valid bit in physical L2 page */ - 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 r10, 0(r11) /* Get the pte */ - - andi. r11, r10, _PAGE_RW /* Is it writeable? */ - beq 2f /* Bail out if not */ - - /* Update 'changed', among others. - */ -#ifdef CONFIG_SWAP - ori r10, r10, _PAGE_DIRTY|_PAGE_HWWRITE - /* do not set the _PAGE_ACCESSED bit of a non-present page */ - andi. r11, r10, _PAGE_PRESENT - beq 4f - ori r10, r10, _PAGE_ACCESSED -4: -#else - ori r10, r10, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE -#endif - mfspr r11, SPRN_MD_TWC /* Get pte address again */ - stw r10, 0(r11) /* and update pte in table */ - - /* The Linux PTE won't go exactly into the MMU TLB. - * Software indicator bits 21, 22 and 28 must be clear. - * Software indicator bits 24, 25, 26, and 27 must be - * set. All other Linux PTE bits control the behavior - * of the MMU. - */ - li r11, 0x00f0 - rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */ - DO_8xx_CPU6(0x3d80, r3) - mtspr SPRN_MD_RPN, r10 /* Update TLB entry */ - - mfspr r10, SPRN_M_TW /* Restore registers */ - lwz r11, 0(r0) - mtcr r11 - lwz r11, 4(r0) -#ifdef CONFIG_8xx_CPU6 - lwz r3, 8(r0) -#endif - rfi -2: + cmpwi cr0, r10, 0x00f0 + beq- FixupDAR /* must be a buggy dcbX, icbi insn. */ +DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR */ mfspr r10, SPRN_M_TW /* Restore registers */ lwz r11, 0(r0) mtcr r11 @@ -588,6 +533,140 @@ 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 + andis. r11, r10, 0x8000 /* Address >= 0x80000000 */ + DO_8xx_CPU6(0x3780, r3) + mtspr SPRN_MD_EPN, r10 + mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */ + beq- 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 @@ -689,12 +768,12 @@ start_here: */ initial_mmu: tlbia /* Invalidate all TLB entries */ -#ifdef CONFIG_PIN_TLB +/* Always pin the first 8 MB ITLB to prevent ITLB + misses while mucking around with SRR0/SRR1 in asm +*/ lis r8, MI_RSV4I@h ori r8, r8, 0x1c00 -#else - li r8, 0 -#endif + mtspr SPRN_MI_CTR, r8 /* Set instruction MMU control */ #ifdef CONFIG_PIN_TLB |
