* [PATCH 0/8] Fix 8xx MMU/TLB. @ 2009-10-11 16:35 Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund 2009-10-14 17:23 ` [PATCH 0/8] Fix 8xx MMU/TLB Scott Wood 0 siblings, 2 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood This is the latest batch of mu 8xx MMU/TLB rework. I think this is complete now and will relax with other work the next few days. I hope I can get some testing from Scott and Rex during this time. Joakim Tjernlund (8): 8xx: invalidate non present TLBs 8xx: Update TLB asm so it behaves as linux mm expects. 8xx: Tag DAR with 0x00f0 to catch buggy instructions. 8xx: Fixup DAR from buggy dcbX instructions. 8xx: dcbst sets store bit in DTLB error, workaround. 8xx: Add missing Guarded setting in DTLB Error. 8xx: Restore _PAGE_WRITETHRU 8xx: start using dcbX instructions in various copy routines arch/powerpc/include/asm/pte-8xx.h | 14 +- arch/powerpc/kernel/head_8xx.S | 307 ++++++++++++++++++++++++++++++------ arch/powerpc/kernel/misc_32.S | 18 -- arch/powerpc/lib/copy_32.S | 24 --- arch/powerpc/mm/fault.c | 8 +- 5 files changed, 269 insertions(+), 102 deletions(-) ^ permalink raw reply [flat|nested] 35+ messages in thread
* [PATCH 1/8] 8xx: invalidate non present TLBs 2009-10-11 16:35 [PATCH 0/8] Fix 8xx MMU/TLB Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund 2009-10-14 16:56 ` [PATCH 1/8] 8xx: invalidate non present TLBs Scott Wood 2009-10-14 17:23 ` [PATCH 0/8] Fix 8xx MMU/TLB Scott Wood 1 sibling, 2 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood 8xx sometimes need to load a invalid/non-present TLBs in it DTLB asm handler. These must be invalidated separaly as linux mm don't. --- arch/powerpc/mm/fault.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 7699394..72941c7 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -39,7 +39,7 @@ #include <asm/uaccess.h> #include <asm/tlbflush.h> #include <asm/siginfo.h> - +#include <mm/mmu_decl.h> #ifdef CONFIG_KPROBES static inline int notify_page_fault(struct pt_regs *regs) @@ -243,6 +243,12 @@ good_area: goto bad_area; #endif /* CONFIG_6xx */ #if defined(CONFIG_8xx) + /* 8xx sometimes need to load a invalid/non-present TLBs. + * These must be invalidated separately as linux mm don't. + */ + if (error_code & 0x40000000) /* no translation? */ + _tlbil_va(address); + /* The MPC8xx seems to always set 0x80000000, which is * "undefined". Of those that can be set, this is the only * one which seems bad. -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects. 2009-10-11 16:35 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund ` (2 more replies) 2009-10-14 16:56 ` [PATCH 1/8] 8xx: invalidate non present TLBs Scott Wood 1 sibling, 3 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood Update the TLB asm to make proper use of _PAGE_DIRY and _PAGE_ACCESSED. Get rid of _PAGE_HWWRITE too. Pros: - I/D TLB Miss never needs to write to the linux pte. - _PAGE_ACCESSED is only set on TLB Error fixing accounting - _PAGE_DIRTY is mapped to 0x100, the changed bit, and is set directly when a page has been made dirty. - Proper RO/RW mapping of user space. - Free up 2 SW TLB bits in the linux pte(add back _PAGE_WRITETHRU ?) - Less instructions in I/D TLB Miss. - kernel RO/user NA support. Cons: - A few more instructions in the TLB Miss routines. --- arch/powerpc/include/asm/pte-8xx.h | 13 ++--- arch/powerpc/kernel/head_8xx.S | 99 ++++++++++++++++++----------------- 2 files changed, 57 insertions(+), 55 deletions(-) diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h index 8c6e312..f23cd15 100644 --- a/arch/powerpc/include/asm/pte-8xx.h +++ b/arch/powerpc/include/asm/pte-8xx.h @@ -32,22 +32,21 @@ #define _PAGE_FILE 0x0002 /* when !present: nonlinear file mapping */ #define _PAGE_NO_CACHE 0x0002 /* I: cache inhibit */ #define _PAGE_SHARED 0x0004 /* No ASID (context) compare */ +#define _PAGE_DIRTY 0x0100 /* C: page changed */ -/* These five software bits must be masked out when the entry is loaded - * into the TLB. +/* These 3 software bits must be masked out when the entry is loaded + * into the TLB, 2 SW bits left. */ #define _PAGE_EXEC 0x0008 /* software: i-cache coherency required */ #define _PAGE_GUARDED 0x0010 /* software: guarded access */ -#define _PAGE_DIRTY 0x0020 /* software: page changed */ -#define _PAGE_RW 0x0040 /* software: user write access allowed */ -#define _PAGE_ACCESSED 0x0080 /* software: page referenced */ +#define _PAGE_ACCESSED 0x0020 /* software: page referenced */ /* Setting any bits in the nibble with the follow two controls will * require a TLB exception handler change. It is assumed unused bits * are always zero. */ -#define _PAGE_HWWRITE 0x0100 /* h/w write enable: never set in Linux PTE */ -#define _PAGE_USER 0x0800 /* One of the PP bits, the other is USER&~RW */ +#define _PAGE_RW 0x0400 /* lsb PP bits, inverted in HW */ +#define _PAGE_USER 0x0800 /* msb PP bits */ #define _PMD_PRESENT 0x0001 #define _PMD_BAD 0x0ff0 diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 52ff8c5..3bf0603 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -333,26 +333,20 @@ 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 +359,22 @@ InstructionTLBMiss: lwz r3, 8(r0) #endif rfi +2: + mfspr r11, SRR1 + /* clear all error bits as TLB Miss + * sets a few unconditionally + */ + rlwinm r11, r11, 0, 0xffff + mtspr 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: @@ -409,21 +419,27 @@ DataStoreTLBMiss: 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, 31, 31 + and r11, r11, r10 + rlwimi r10, r11, 0, 31, 31 + + /* Honour kernel RO, User NA */ + andi. r11, r10, _PAGE_USER | _PAGE_RW + bne- cr0, 5f + ori r10,r10, 0x200 /* Extended encoding, bit 22 */ +5: xori r10, r10, _PAGE_RW /* invert RW bit */ /* 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. @@ -469,11 +485,12 @@ DataTLBError: stw r10, 0(r0) stw r11, 4(r0) - /* First, make sure this was a store operation. + mfspr r11, SPRN_DSISR + andis. r11, r11, 0x4800 /* !translation or protection */ + bne 2f /* branch if either is set */ + /* Only Change bit left now, do it here as it is faster + * than trapping to the C fault handler. */ - 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 @@ -522,26 +539,12 @@ DataTLBError: 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 */ + ori r10, r10, _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HWWRITE stw r10, 0(r11) /* and update pte in table */ + xori r10, r10, _PAGE_RW /* RW bit is inverted */ /* 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. -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions. 2009-10-11 16:35 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund 2009-10-11 21:25 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Benjamin Herrenschmidt 2009-10-14 16:57 ` Scott Wood 2 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood dcbz, dcbf, dcbi, dcbst and icbi do not set DAR when they cause a DTLB Error. Dectect this by tagging DAR with 0x00f0 at every exception exit that modifies DAR. Test for DAR=0x00f0 in DataTLBError and bail to handle_page_fault(). --- arch/powerpc/kernel/head_8xx.S | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 3bf0603..093176c 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 @@ -445,6 +451,7 @@ DataStoreTLBMiss: * 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 */ @@ -485,6 +492,10 @@ DataTLBError: stw r10, 0(r0) stw r11, 4(r0) + mfspr r10, SPRN_DAR + cmpwi cr0, r10, 0x00f0 + beq- 2f /* must be a buggy dcbX, icbi insn. */ + mfspr r11, SPRN_DSISR andis. r11, r11, 0x4800 /* !translation or protection */ bne 2f /* branch if either is set */ @@ -508,7 +519,8 @@ DataTLBError: * are initialized in mapin_ram(). This will avoid the problem, * assuming we only use the dcbi instruction on kernel addresses. */ - mfspr r10, SPRN_DAR + + /* DAR is in r10 already */ rlwinm r11, r10, 0, 0, 19 ori r11, r11, MD_EVALID mfspr r10, SPRN_M_CASID @@ -550,6 +562,7 @@ DataTLBError: * of the MMU. */ 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 */ -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-11 16:35 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Joakim Tjernlund 2009-10-14 17:20 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Scott Wood 0 siblings, 2 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood This is an assembler version to fixup DAR not being set by dcbX, icbi instructions. There are two versions, one uses selfmodifing code, the other uses a jump table but is much bigger(default). --- arch/powerpc/kernel/head_8xx.S | 146 +++++++++++++++++++++++++++++++++++++++- 1 files changed, 145 insertions(+), 1 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 093176c..9839e79 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -494,7 +494,8 @@ DataTLBError: mfspr r10, SPRN_DAR cmpwi cr0, r10, 0x00f0 - beq- 2f /* must be a buggy dcbX, icbi insn. */ + beq- FixDAR /* must be a buggy dcbX, icbi insn. */ +DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR */ mfspr r11, SPRN_DSISR andis. r11, r11, 0x4800 /* !translation or protection */ @@ -604,6 +605,149 @@ 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 NO_SELF_MODIFYING_CODE /* define if you don't want to use self modifying code */ + nop /* A few nops to make the modified_instr: space below cache line aligned */ + nop +139: /* fetch instruction from userspace memory */ + DO_8xx_CPU6(0x3780, r3) + mtspr SPRN_MD_EPN, r10 + mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */ + lwz r11, 0(r11) /* Get the level 1 entry */ + tophys (r11, r11) + 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 + b 140f +FixDAR: /* Entry point for dcbx workaround. */ + /* fetch instruction from memory. */ + mfspr r10, SPRN_SRR0 + andis. r11, r10, 0x8000 + tophys (r11, r10) + beq- 139b /* Branch if user space address */ +140: lwz r11,0(r11) +#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/and 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 DARFix /* 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 + add r10, r10, r10 + b 151f + add r10, r10, r11 + b 151f + 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 + mtctr r11 /* r10 needs special handling */ + b 154f + mtctr r11 /* r11 needs special handling */ + b 153f + 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, r25 + 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 DARFix /* 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 -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround. 2009-10-11 16:35 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Joakim Tjernlund 2009-10-14 17:02 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Scott Wood 2009-10-14 17:20 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Scott Wood 1 sibling, 2 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood dcbst should not set the store bit(bit 6, DSISR) when trapping into a DTLB Error. Clear this bit while doing the dcbX missing DAR workaround. --- arch/powerpc/kernel/head_8xx.S | 34 +++++++++++++++++++++++++++++++--- 1 files changed, 31 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 9839e79..027856e 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -496,10 +496,14 @@ DataTLBError: cmpwi cr0, r10, 0x00f0 beq- FixDAR /* must be a buggy dcbX, icbi insn. */ DARFix: /* 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. */ @@ -632,6 +636,30 @@ FixDAR: /* Entry point for dcbx workaround. */ tophys (r11, r10) beq- 139b /* Branch if user space address */ 140: 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 DARfix /* 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 -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error. 2009-10-11 16:35 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Joakim Tjernlund 2009-10-11 21:25 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Benjamin Herrenschmidt 2009-10-14 17:02 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Scott Wood 1 sibling, 2 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood only DTLB Miss did set this bit, DTLB Error needs too otherwise the setting is lost when the page becomes dirty. --- arch/powerpc/kernel/head_8xx.S | 13 ++++++++++--- 1 files changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 027856e..371b606 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -552,9 +552,16 @@ DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR * */ 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 */ + mtspr SPRN_MD_TWC, r11 /* Load pte table base address */ + mfspr r10, SPRN_MD_TWC /* ....and get the pte address */ + lwz r10, 0(r10) /* Get the pte */ + /* Insert the Guarded flag into the TWC from the Linux PTE. + * It is bit 27 of both the Linux PTE and the TWC + */ + rlwimi r11, r10, 0, 27, 27 + DO_8xx_CPU6(0x3b80, r3) + mtspr SPRN_MD_TWC, r11 + mfspr r11, SPRN_MD_TWC /* get the pte address again */ ori r10, r10, _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HWWRITE stw r10, 0(r11) /* and update pte in table */ -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU 2009-10-11 16:35 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 8/8] 8xx: start using dcbX instructions in various copy routines Joakim Tjernlund 2009-10-11 21:26 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Benjamin Herrenschmidt 2009-10-11 21:25 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Benjamin Herrenschmidt 1 sibling, 2 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood 8xx has not had WRITETHRU due to lack of bits in the pte. After the recent rewrite of the 8xx TLB code, there are two bits left. Use one of them to WRITETHRU. Perhaps use the last SW bit to PAGE_SPECIAL or PAGE_FILE? --- arch/powerpc/include/asm/pte-8xx.h | 5 +++-- arch/powerpc/kernel/head_8xx.S | 8 ++++++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h index f23cd15..9349d83 100644 --- a/arch/powerpc/include/asm/pte-8xx.h +++ b/arch/powerpc/include/asm/pte-8xx.h @@ -34,12 +34,13 @@ #define _PAGE_SHARED 0x0004 /* No ASID (context) compare */ #define _PAGE_DIRTY 0x0100 /* C: page changed */ -/* These 3 software bits must be masked out when the entry is loaded - * into the TLB, 2 SW bits left. +/* These 4 software bits must be masked out when the entry is loaded + * into the TLB, 1 SW bit left(0x0080). */ #define _PAGE_EXEC 0x0008 /* software: i-cache coherency required */ #define _PAGE_GUARDED 0x0010 /* software: guarded access */ #define _PAGE_ACCESSED 0x0020 /* software: page referenced */ +#define _PAGE_WRITETHRU 0x0040 /* software: caching is write through */ /* Setting any bits in the nibble with the follow two controls will * require a TLB exception handler change. It is assumed unused bits diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 371b606..db5207e 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -422,6 +422,10 @@ 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 @@ -559,6 +563,10 @@ DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR * * It is bit 27 of both the Linux PTE and the TWC */ 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 mfspr r11, SPRN_MD_TWC /* get the pte address again */ -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 8/8] 8xx: start using dcbX instructions in various copy routines 2009-10-11 16:35 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Joakim Tjernlund @ 2009-10-11 16:35 ` Joakim Tjernlund 2009-10-11 21:26 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Benjamin Herrenschmidt 1 sibling, 0 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 16:35 UTC (permalink / raw) To: Benjamin Herrenschmidt, linuxppc-dev, Rex Feany, Scott Wood Now that 8xx can fixup dcbX instructions, start using them where possible like every other PowerPc arch do. --- arch/powerpc/kernel/misc_32.S | 18 ------------------ arch/powerpc/lib/copy_32.S | 24 ------------------------ 2 files changed, 0 insertions(+), 42 deletions(-) diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 15f28e0..b92095e 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -495,15 +495,7 @@ _GLOBAL(clear_pages) li r0,PAGE_SIZE/L1_CACHE_BYTES slw r0,r0,r4 mtctr r0 -#ifdef CONFIG_8xx - li r4, 0 -1: stw r4, 0(r3) - stw r4, 4(r3) - stw r4, 8(r3) - stw r4, 12(r3) -#else 1: dcbz 0,r3 -#endif addi r3,r3,L1_CACHE_BYTES bdnz 1b blr @@ -528,15 +520,6 @@ _GLOBAL(copy_page) addi r3,r3,-4 addi r4,r4,-4 -#ifdef CONFIG_8xx - /* don't use prefetch on 8xx */ - li r0,4096/L1_CACHE_BYTES - mtctr r0 -1: COPY_16_BYTES - bdnz 1b - blr - -#else /* not 8xx, we can prefetch */ li r5,4 #if MAX_COPY_PREFETCH > 1 @@ -577,7 +560,6 @@ _GLOBAL(copy_page) li r0,MAX_COPY_PREFETCH li r11,4 b 2b -#endif /* CONFIG_8xx */ /* * void atomic_clear_mask(atomic_t mask, atomic_t *addr) diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S index c657de5..74a7f41 100644 --- a/arch/powerpc/lib/copy_32.S +++ b/arch/powerpc/lib/copy_32.S @@ -98,20 +98,7 @@ _GLOBAL(cacheable_memzero) bdnz 4b 3: mtctr r9 li r7,4 -#if !defined(CONFIG_8xx) 10: dcbz r7,r6 -#else -10: stw r4, 4(r6) - stw r4, 8(r6) - stw r4, 12(r6) - stw r4, 16(r6) -#if CACHE_LINE_SIZE >= 32 - stw r4, 20(r6) - stw r4, 24(r6) - stw r4, 28(r6) - stw r4, 32(r6) -#endif /* CACHE_LINE_SIZE */ -#endif addi r6,r6,CACHELINE_BYTES bdnz 10b clrlwi r5,r8,32-LG_CACHELINE_BYTES @@ -200,9 +187,7 @@ _GLOBAL(cacheable_memcpy) mtctr r0 beq 63f 53: -#if !defined(CONFIG_8xx) dcbz r11,r6 -#endif COPY_16_BYTES #if L1_CACHE_BYTES >= 32 COPY_16_BYTES @@ -356,14 +341,6 @@ _GLOBAL(__copy_tofrom_user) li r11,4 beq 63f -#ifdef CONFIG_8xx - /* Don't use prefetch on 8xx */ - mtctr r0 - li r0,0 -53: COPY_16_BYTES_WITHEX(0) - bdnz 53b - -#else /* not CONFIG_8xx */ /* Here we decide how far ahead to prefetch the source */ li r3,4 cmpwi r0,1 @@ -416,7 +393,6 @@ _GLOBAL(__copy_tofrom_user) li r3,4 li r7,0 bne 114b -#endif /* CONFIG_8xx */ 63: srwi. r0,r5,2 mtctr r0 -- 1.6.4.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* Re: [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU 2009-10-11 16:35 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 8/8] 8xx: start using dcbX instructions in various copy routines Joakim Tjernlund @ 2009-10-11 21:26 ` Benjamin Herrenschmidt 2009-10-11 22:21 ` Joakim Tjernlund 1 sibling, 1 reply; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-11 21:26 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Scott Wood, linuxppc-dev, Rex Feany On Sun, 2009-10-11 at 18:35 +0200, Joakim Tjernlund wrote: > 8xx has not had WRITETHRU due to lack of bits in the pte. > After the recent rewrite of the 8xx TLB code, there are > two bits left. Use one of them to WRITETHRU. > > Perhaps use the last SW bit to PAGE_SPECIAL or PAGE_FILE? _PAGE_FILE can already overwrite other bits as it's only set when !present, and should pretty much always be 0x2 I think I've replaced _PAGE_EXEC with _PAGE_SPECIAL already upstream since _PAGE_EXEC is unused on 8xx. Cheers, Ben. > --- > arch/powerpc/include/asm/pte-8xx.h | 5 +++-- > arch/powerpc/kernel/head_8xx.S | 8 ++++++++ > 2 files changed, 11 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h > index f23cd15..9349d83 100644 > --- a/arch/powerpc/include/asm/pte-8xx.h > +++ b/arch/powerpc/include/asm/pte-8xx.h > @@ -34,12 +34,13 @@ > #define _PAGE_SHARED 0x0004 /* No ASID (context) compare */ > #define _PAGE_DIRTY 0x0100 /* C: page changed */ > > -/* These 3 software bits must be masked out when the entry is loaded > - * into the TLB, 2 SW bits left. > +/* These 4 software bits must be masked out when the entry is loaded > + * into the TLB, 1 SW bit left(0x0080). > */ > #define _PAGE_EXEC 0x0008 /* software: i-cache coherency required */ > #define _PAGE_GUARDED 0x0010 /* software: guarded access */ > #define _PAGE_ACCESSED 0x0020 /* software: page referenced */ > +#define _PAGE_WRITETHRU 0x0040 /* software: caching is write through */ > > /* Setting any bits in the nibble with the follow two controls will > * require a TLB exception handler change. It is assumed unused bits > diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S > index 371b606..db5207e 100644 > --- a/arch/powerpc/kernel/head_8xx.S > +++ b/arch/powerpc/kernel/head_8xx.S > @@ -422,6 +422,10 @@ 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 > > @@ -559,6 +563,10 @@ DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR * > * It is bit 27 of both the Linux PTE and the TWC > */ > 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 > mfspr r11, SPRN_MD_TWC /* get the pte address again */ ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU 2009-10-11 21:26 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Benjamin Herrenschmidt @ 2009-10-11 22:21 ` Joakim Tjernlund 2009-10-11 22:45 ` Benjamin Herrenschmidt 0 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 22:21 UTC (permalink / raw) To: Benjamin Herrenschmidt; +Cc: Scott Wood, linuxppc-dev, Rex Feany Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 11/10/2009 23:26:27: > > On Sun, 2009-10-11 at 18:35 +0200, Joakim Tjernlund wrote: > > 8xx has not had WRITETHRU due to lack of bits in the pte. > > After the recent rewrite of the 8xx TLB code, there are > > two bits left. Use one of them to WRITETHRU. > > > > Perhaps use the last SW bit to PAGE_SPECIAL or PAGE_FILE? > > _PAGE_FILE can already overwrite other bits as it's only set > when !present, and should pretty much always be 0x2 OK. > > I think I've replaced _PAGE_EXEC with _PAGE_SPECIAL already > upstream since _PAGE_EXEC is unused on 8xx. What is page SPECIAL anyway? ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU 2009-10-11 22:21 ` Joakim Tjernlund @ 2009-10-11 22:45 ` Benjamin Herrenschmidt 0 siblings, 0 replies; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-11 22:45 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Scott Wood, linuxppc-dev, Rex Feany On Mon, 2009-10-12 at 00:21 +0200, Joakim Tjernlund wrote: > > I think I've replaced _PAGE_EXEC with _PAGE_SPECIAL already > > upstream since _PAGE_EXEC is unused on 8xx. > > What is page SPECIAL anyway? It's used on newer kernels to indicates PTEs that map something that isn't backed by a struct page (ie, not memory) Cheers, Ben. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error. 2009-10-11 16:35 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Joakim Tjernlund @ 2009-10-11 21:25 ` Benjamin Herrenschmidt 2009-10-11 22:19 ` Joakim Tjernlund 1 sibling, 1 reply; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-11 21:25 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Scott Wood, linuxppc-dev, Rex Feany On Sun, 2009-10-11 at 18:35 +0200, Joakim Tjernlund wrote: > only DTLB Miss did set this bit, DTLB Error needs too otherwise > the setting is lost when the page becomes dirty. Easier fix: Stop doing thing in DTLB Error Ben. > -- > arch/powerpc/kernel/head_8xx.S | 13 ++++++++++--- > 1 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S > index 027856e..371b606 100644 > --- a/arch/powerpc/kernel/head_8xx.S > +++ b/arch/powerpc/kernel/head_8xx.S > @@ -552,9 +552,16 @@ DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR * > */ > 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 */ > + mtspr SPRN_MD_TWC, r11 /* Load pte table base address */ > + mfspr r10, SPRN_MD_TWC /* ....and get the pte address */ > + lwz r10, 0(r10) /* Get the pte */ > + /* Insert the Guarded flag into the TWC from the Linux PTE. > + * It is bit 27 of both the Linux PTE and the TWC > + */ > + rlwimi r11, r10, 0, 27, 27 > + DO_8xx_CPU6(0x3b80, r3) > + mtspr SPRN_MD_TWC, r11 > + mfspr r11, SPRN_MD_TWC /* get the pte address again */ > > ori r10, r10, _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HWWRITE > stw r10, 0(r11) /* and update pte in table */ ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error. 2009-10-11 21:25 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Benjamin Herrenschmidt @ 2009-10-11 22:19 ` Joakim Tjernlund 2009-10-11 22:44 ` Benjamin Herrenschmidt 0 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-11 22:19 UTC (permalink / raw) To: Benjamin Herrenschmidt; +Cc: Scott Wood, linuxppc-dev, Rex Feany Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 11/10/2009 23:25:30: > > On Sun, 2009-10-11 at 18:35 +0200, Joakim Tjernlund wrote: > > only DTLB Miss did set this bit, DTLB Error needs too otherwise > > the setting is lost when the page becomes dirty. > > Easier fix: Stop doing thing in DTLB Error > > Ben. I hear you, I can remove DTLB error with an add on patch later if that is OK? I cannot remove the DARFix though, when I move that to do_page_fault(), I get duplicate TLB hits on the same insn. It is like when transfer_to_handler() executes rfi, the cpu restarts the the faulting insn instead of jumping to the page fault handler, not always but often. Jocke ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error. 2009-10-11 22:19 ` Joakim Tjernlund @ 2009-10-11 22:44 ` Benjamin Herrenschmidt 2009-10-12 5:36 ` Joakim Tjernlund 0 siblings, 1 reply; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-11 22:44 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Scott Wood, linuxppc-dev, Rex Feany On Mon, 2009-10-12 at 00:19 +0200, Joakim Tjernlund wrote: > > I hear you, I can remove DTLB error with an add on patch later if that is OK? > I cannot remove the DARFix though, when I move that to do_page_fault(), I get > duplicate TLB hits on the same insn. It is like when transfer_to_handler() > executes rfi, the cpu restarts the the faulting insn instead of jumping > to the page fault handler, not always but often. I'm not sure what you mean here ... Ben. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error. 2009-10-11 22:44 ` Benjamin Herrenschmidt @ 2009-10-12 5:36 ` Joakim Tjernlund 2009-10-12 5:46 ` Benjamin Herrenschmidt 0 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-12 5:36 UTC (permalink / raw) To: Benjamin Herrenschmidt; +Cc: Scott Wood, linuxppc-dev, Rex Feany Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 12/10/2009 00:44:56: > On Mon, 2009-10-12 at 00:19 +0200, Joakim Tjernlund wrote: > > > > I hear you, I can remove DTLB error with an add on patch later if that is OK? > > I cannot remove the DARFix though, when I move that to do_page_fault(), I get > > duplicate TLB hits on the same insn. It is like when transfer_to_handler() > > executes rfi, the cpu restarts the the faulting insn instead of jumping > > to the page fault handler, not always but often. > > I'm not sure what you mean here ... Just that I need to keep the DAR fix for dcbX insn in the DTLB handler. If I try to move it to do_page_fault() I get a lot more DTLB errors for dcbX insn. Jocke ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error. 2009-10-12 5:36 ` Joakim Tjernlund @ 2009-10-12 5:46 ` Benjamin Herrenschmidt 2009-10-12 6:59 ` Joakim Tjernlund 0 siblings, 1 reply; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-12 5:46 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Scott Wood, linuxppc-dev, Rex Feany On Mon, 2009-10-12 at 07:36 +0200, Joakim Tjernlund wrote: > Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 12/10/2009 00:44:56: > > On Mon, 2009-10-12 at 00:19 +0200, Joakim Tjernlund wrote: > > > > > > I hear you, I can remove DTLB error with an add on patch later if that is OK? > > > I cannot remove the DARFix though, when I move that to do_page_fault(), I get > > > duplicate TLB hits on the same insn. It is like when transfer_to_handler() > > > executes rfi, the cpu restarts the the faulting insn instead of jumping > > > to the page fault handler, not always but often. > > > > I'm not sure what you mean here ... > > Just that I need to keep the DAR fix for dcbX insn in the DTLB handler. If I try > to move it to do_page_fault() I get a lot more DTLB errors for dcbX insn. I'm not sure why (ie, I didn't get your explanation about rfi and restarting the faulting insn etc...) but ok, I don't mind having the DAR fixup remain in the asm. It's the whole logic that looks at the PTE and does things with it that I feel has no room in there :-) BTW. Maybe the do_page_fault() thing comes from the fact that we also go there via ITLB Error which doesn't set the DAR and that's normal ? Cheers, Ben. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error. 2009-10-12 5:46 ` Benjamin Herrenschmidt @ 2009-10-12 6:59 ` Joakim Tjernlund 0 siblings, 0 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-12 6:59 UTC (permalink / raw) To: Benjamin Herrenschmidt; +Cc: Scott Wood, linuxppc-dev, Rex Feany Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 12/10/2009 07:46:14: > > On Mon, 2009-10-12 at 07:36 +0200, Joakim Tjernlund wrote: > > Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 12/10/2009 00:44:56: > > > On Mon, 2009-10-12 at 00:19 +0200, Joakim Tjernlund wrote: > > > > > > > > I hear you, I can remove DTLB error with an add on patch later if that is OK? > > > > I cannot remove the DARFix though, when I move that to do_page_fault(), I get > > > > duplicate TLB hits on the same insn. It is like when transfer_to_handler() > > > > executes rfi, the cpu restarts the the faulting insn instead of jumping > > > > to the page fault handler, not always but often. > > > > > > I'm not sure what you mean here ... > > > > Just that I need to keep the DAR fix for dcbX insn in the DTLB handler. If I try > > to move it to do_page_fault() I get a lot more DTLB errors for dcbX insn. > > I'm not sure why (ie, I didn't get your explanation about rfi and > restarting the faulting insn etc...) but ok, I don't mind having > the DAR fixup remain in the asm. It's the whole logic that looks > at the PTE and does things with it that I feel has no room in there :-) OK, I will send a removal patch too. > > BTW. Maybe the do_page_fault() thing comes from the fact that we > also go there via ITLB Error which doesn't set the DAR and > that's normal ? I had that idea to, but no. These have different traps numbers and address is set to SRR0 for ITLB and to DAR for DTLB. I test for DTLB trap number before doing anything. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround. 2009-10-11 16:35 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Joakim Tjernlund @ 2009-10-14 17:02 ` Scott Wood 1 sibling, 0 replies; 35+ messages in thread From: Scott Wood @ 2009-10-14 17:02 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev On Sun, Oct 11, 2009 at 06:35:09PM +0200, Joakim Tjernlund wrote: > DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR */ [snip] > + b DARfix /* Nope, go back to normal TLB processing */ arch/powerpc/kernel/head_8xx.S:577: undefined reference to `DARfix' -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-11 16:35 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Joakim Tjernlund @ 2009-10-14 17:20 ` Scott Wood 2009-10-14 19:05 ` Joakim Tjernlund 1 sibling, 1 reply; 35+ messages in thread From: Scott Wood @ 2009-10-14 17:20 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev On Sun, Oct 11, 2009 at 06:35:08PM +0200, Joakim Tjernlund wrote: > This is an assembler version to fixup DAR not being set > by dcbX, icbi instructions. There are two versions, one > uses selfmodifing code, the other uses a > jump table but is much bigger(default). > --- > arch/powerpc/kernel/head_8xx.S | 146 +++++++++++++++++++++++++++++++++++++++- > 1 files changed, 145 insertions(+), 1 deletions(-) > > diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S > index 093176c..9839e79 100644 > --- a/arch/powerpc/kernel/head_8xx.S > +++ b/arch/powerpc/kernel/head_8xx.S > @@ -494,7 +494,8 @@ DataTLBError: > > mfspr r10, SPRN_DAR > cmpwi cr0, r10, 0x00f0 > - beq- 2f /* must be a buggy dcbX, icbi insn. */ > + beq- FixDAR /* must be a buggy dcbX, icbi insn. */ > +DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR */ Both FixDAR and DARFix? Could we make the labels a little clearer? > +/* 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. > + */ How often does this happen? Could we just do it in C code after saving all the registers, and avoid the self modifying stuff (or the big switch statement equivalent)? -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 17:20 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Scott Wood @ 2009-10-14 19:05 ` Joakim Tjernlund 2009-10-14 19:23 ` Scott Wood 0 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-14 19:05 UTC (permalink / raw) To: Scott Wood; +Cc: Rex Feany, linuxppc-dev Scott Wood <scottwood@freescale.com> wrote on 14/10/2009 19:20:03: > > On Sun, Oct 11, 2009 at 06:35:08PM +0200, Joakim Tjernlund wrote: > > This is an assembler version to fixup DAR not being set > > by dcbX, icbi instructions. There are two versions, one > > uses selfmodifing code, the other uses a > > jump table but is much bigger(default). > > --- > > arch/powerpc/kernel/head_8xx.S | 146 +++++++++++++++++++++++++++++++++++++++- > > 1 files changed, 145 insertions(+), 1 deletions(-) > > > > diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S > > index 093176c..9839e79 100644 > > --- a/arch/powerpc/kernel/head_8xx.S > > +++ b/arch/powerpc/kernel/head_8xx.S > > @@ -494,7 +494,8 @@ DataTLBError: > > > > mfspr r10, SPRN_DAR > > cmpwi cr0, r10, 0x00f0 > > - beq- 2f /* must be a buggy dcbX, icbi insn. */ > > + beq- FixDAR /* must be a buggy dcbX, icbi insn. */ > > +DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR */ > > Both FixDAR and DARFix? Could we make the labels a little clearer? Yes, need to come up with better names :) > > > +/* 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. > > + */ > > How often does this happen? Could we just do it in C code after saving all > the registers, and avoid the self modifying stuff (or the big switch > statement equivalent)? I had some problems with the C-version. I got lots of extra TLB errors for the same address so I am not confident it will work in the long run. BTW, you could add a test and printk in do_page_fault on address 0x000000f0. if that ever hits there is a problem with dcbX fixup. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 19:05 ` Joakim Tjernlund @ 2009-10-14 19:23 ` Scott Wood 2009-10-14 20:03 ` Joakim Tjernlund 0 siblings, 1 reply; 35+ messages in thread From: Scott Wood @ 2009-10-14 19:23 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev Joakim Tjernlund wrote: > BTW, you could add a test and printk in do_page_fault on address 0x000000f0. > if that ever hits there is a problem with dcbX fixup. It doesn't get any 0xf0 faults. FWIW, I'm not seeing the segfault any more, but I still get the lockup. -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 19:23 ` Scott Wood @ 2009-10-14 20:03 ` Joakim Tjernlund 2009-10-14 20:22 ` Scott Wood 0 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-14 20:03 UTC (permalink / raw) To: Scott Wood; +Cc: Rex Feany, linuxppc-dev Scott Wood <scottwood@freescale.com> wrote on 14/10/2009 21:23:02: > Joakim Tjernlund wrote: > > BTW, you could add a test and printk in do_page_fault on address 0x000000f0. > > if that ever hits there is a problem with dcbX fixup. > > It doesn't get any 0xf0 faults. > > FWIW, I'm not seeing the segfault any more, but I still get the lockup. Have you reverted 8xx: start using dcbX instructions in various copy routines ? After that you could stick a b DataAccess directly in the DTLB error handler to skip and dcbX fixups. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 20:03 ` Joakim Tjernlund @ 2009-10-14 20:22 ` Scott Wood 2009-10-14 21:10 ` Joakim Tjernlund 0 siblings, 1 reply; 35+ messages in thread From: Scott Wood @ 2009-10-14 20:22 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev Joakim Tjernlund wrote: > Scott Wood <scottwood@freescale.com> wrote on 14/10/2009 21:23:02: >> Joakim Tjernlund wrote: >>> BTW, you could add a test and printk in do_page_fault on address 0x000000f0. >>> if that ever hits there is a problem with dcbX fixup. >> It doesn't get any 0xf0 faults. >> >> FWIW, I'm not seeing the segfault any more, but I still get the lockup. > > Have you reverted > 8xx: start using dcbX instructions in various copy routines ? > > After that you could stick a > b DataAccess > > directly in the DTLB error handler to skip and dcbX fixups. With that, I don't see the hard lockup, but things get stuck during bootup with everything idle. I see this even if I revert everything but the "invalidate non present TLBs" patch, and I was seeing similar things sometimes with the other tlbil_va hacks. I think there's something else going on in the 2.6 8xx code that needs to be fixed before we can tell what the impact of these patches is. I'll look into it. -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 20:22 ` Scott Wood @ 2009-10-14 21:10 ` Joakim Tjernlund 2009-10-14 21:14 ` Scott Wood 0 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-14 21:10 UTC (permalink / raw) To: Scott Wood; +Cc: Rex Feany, linuxppc-dev Scott Wood <scottwood@freescale.com> wrote on 14/10/2009 22:22:25: > > Joakim Tjernlund wrote: > > Scott Wood <scottwood@freescale.com> wrote on 14/10/2009 21:23:02: > >> Joakim Tjernlund wrote: > >>> BTW, you could add a test and printk in do_page_fault on address 0x000000f0. > >>> if that ever hits there is a problem with dcbX fixup. > >> It doesn't get any 0xf0 faults. > >> > >> FWIW, I'm not seeing the segfault any more, but I still get the lockup. > > > > Have you reverted > > 8xx: start using dcbX instructions in various copy routines ? > > > > After that you could stick a > > b DataAccess > > > > directly in the DTLB error handler to skip and dcbX fixups. > > With that, I don't see the hard lockup, but things get stuck during You needed both to loose the hard lockup? I would think it should be enough to revert the "various copy routines" stuff? I figure that these routines aren't working in 8xx for other reasons since they haven't been used on 8xx since at least early 2.4. > bootup with everything idle. I see this even if I revert everything but > the "invalidate non present TLBs" patch, and I was seeing similar things > sometimes with the other tlbil_va hacks. OK, something else is up. > > I think there's something else going on in the 2.6 8xx code that needs > to be fixed before we can tell what the impact of these patches is. > I'll look into it. Great because I am really out of ideas. Perhaps back down to 2.6.30 and test from there? ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 21:10 ` Joakim Tjernlund @ 2009-10-14 21:14 ` Scott Wood 2009-10-14 21:17 ` Benjamin Herrenschmidt 0 siblings, 1 reply; 35+ messages in thread From: Scott Wood @ 2009-10-14 21:14 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev Joakim Tjernlund wrote: >> With that, I don't see the hard lockup, but things get stuck during > > You needed both to loose the hard lockup? I would think > it should be enough to revert the "various copy routines" stuff? No, but when I just reverted the patch and didn't change the TLB error handler, I got some other weirdness (assertion failure in some userspace program). It may have been coincidental, though. >> I think there's something else going on in the 2.6 8xx code that needs >> to be fixed before we can tell what the impact of these patches is. >> I'll look into it. > > Great because I am really out of ideas. Perhaps back down to 2.6.30 and test > from there? I think the last working version was a little older than that -- and it's quite possible that there was underlying badness even earlier that just recently got exposed. I think I want to just debug it and find out what's really going on. -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 21:14 ` Scott Wood @ 2009-10-14 21:17 ` Benjamin Herrenschmidt 2009-10-14 21:41 ` Joakim Tjernlund 0 siblings, 1 reply; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-14 21:17 UTC (permalink / raw) To: Scott Wood; +Cc: linuxppc-dev, Rex Feany On Wed, 2009-10-14 at 16:14 -0500, Scott Wood wrote: > > I think the last working version was a little older than that -- and it's quite > possible that there was underlying badness even earlier that just recently got > exposed. I think I want to just debug it and find out what's really going on. That would be good :-) I've been itching to do that but without HW it's not trivial :-) Cheers, Ben. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 21:17 ` Benjamin Herrenschmidt @ 2009-10-14 21:41 ` Joakim Tjernlund 2009-10-14 21:52 ` Benjamin Herrenschmidt 0 siblings, 1 reply; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-14 21:41 UTC (permalink / raw) To: Benjamin Herrenschmidt; +Cc: Scott Wood, linuxppc-dev, Rex Feany Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 14/10/2009 23:17:09: > > On Wed, 2009-10-14 at 16:14 -0500, Scott Wood wrote: > > > > I think the last working version was a little older than that -- and it's quite > > possible that there was underlying badness even earlier that just recently got > > exposed. I think I want to just debug it and find out what's really going on. > > That would be good :-) > > I've been itching to do that but without HW it's not trivial :-) Meanwhile, how about the tlb asm you promised me? :) It will be a challenge I think since you only have 2 GPRs I guess it would be possible to stash yet another reg since it will fit in the cache line already used by the TLB handlers. Jocke ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 21:41 ` Joakim Tjernlund @ 2009-10-14 21:52 ` Benjamin Herrenschmidt 2009-10-14 22:09 ` Joakim Tjernlund 0 siblings, 1 reply; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-14 21:52 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Scott Wood, linuxppc-dev, Rex Feany On Wed, 2009-10-14 at 23:41 +0200, Joakim Tjernlund wrote: > Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 14/10/2009 23:17:09: > > > > On Wed, 2009-10-14 at 16:14 -0500, Scott Wood wrote: > > > > > > I think the last working version was a little older than that -- and it's quite > > > possible that there was underlying badness even earlier that just recently got > > > exposed. I think I want to just debug it and find out what's really going on. > > > > That would be good :-) > > > > I've been itching to do that but without HW it's not trivial :-) > > Meanwhile, how about the tlb asm you promised me? :) > It will be a challenge I think since you only have 2 GPRs > I guess it would be possible to stash yet another reg since it > will fit in the cache line already used by the TLB handlers. Let's just get it working first :-) Ben. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions. 2009-10-14 21:52 ` Benjamin Herrenschmidt @ 2009-10-14 22:09 ` Joakim Tjernlund 0 siblings, 0 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-14 22:09 UTC (permalink / raw) To: Benjamin Herrenschmidt; +Cc: Scott Wood, linuxppc-dev, Rex Feany Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 14/10/2009 23:52:10: > > On Wed, 2009-10-14 at 23:41 +0200, Joakim Tjernlund wrote: > > Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 14/10/2009 23:17:09: > > > > > > On Wed, 2009-10-14 at 16:14 -0500, Scott Wood wrote: > > > > > > > > I think the last working version was a little older than that -- and it's quite > > > > possible that there was underlying badness even earlier that just recently got > > > > exposed. I think I want to just debug it and find out what's really going on. > > > > > > That would be good :-) > > > > > > I've been itching to do that but without HW it's not trivial :-) > > > > Meanwhile, how about the tlb asm you promised me? :) > > It will be a challenge I think since you only have 2 GPRs > > I guess it would be possible to stash yet another reg since it > > will fit in the cache line already used by the TLB handlers. > > Let's just get it working first :-) Chicken :):) ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects. 2009-10-11 16:35 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund @ 2009-10-11 21:25 ` Benjamin Herrenschmidt 2009-10-14 16:57 ` Scott Wood 2 siblings, 0 replies; 35+ messages in thread From: Benjamin Herrenschmidt @ 2009-10-11 21:25 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Scott Wood, linuxppc-dev, Rex Feany On Sun, 2009-10-11 at 18:35 +0200, Joakim Tjernlund wrote: > @@ -522,26 +539,12 @@ DataTLBError: I still think you should remove everything from DataTLBError, it's just plain useless :-) Ben. > 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 */ > + ori r10, r10, _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HWWRITE > stw r10, 0(r11) /* and update pte in table */ > + xori r10, r10, _PAGE_RW /* RW bit is inverted */ > > /* 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. > -- > 1.6.4.4 > > ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects. 2009-10-11 16:35 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund 2009-10-11 21:25 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Benjamin Herrenschmidt @ 2009-10-14 16:57 ` Scott Wood 2 siblings, 0 replies; 35+ messages in thread From: Scott Wood @ 2009-10-14 16:57 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev On Sun, Oct 11, 2009 at 06:35:06PM +0200, Joakim Tjernlund wrote: > + mfspr r11, SRR1 > + /* clear all error bits as TLB Miss > + * sets a few unconditionally > + */ > + rlwinm r11, r11, 0, 0xffff > + mtspr SRR1, r11 arch/powerpc/kernel/head_8xx.S:369: Error: unsupported relocation against SRR1 arch/powerpc/kernel/head_8xx.S:374: Error: unsupported relocation against SRR1 -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 1/8] 8xx: invalidate non present TLBs 2009-10-11 16:35 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund @ 2009-10-14 16:56 ` Scott Wood 1 sibling, 0 replies; 35+ messages in thread From: Scott Wood @ 2009-10-14 16:56 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev On Sun, Oct 11, 2009 at 06:35:05PM +0200, Joakim Tjernlund wrote: > 8xx sometimes need to load a invalid/non-present TLBs in > it DTLB asm handler. > These must be invalidated separaly as linux mm don't. > --- > arch/powerpc/mm/fault.c | 8 +++++++- > 1 files changed, 7 insertions(+), 1 deletions(-) > > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > index 7699394..72941c7 100644 > --- a/arch/powerpc/mm/fault.c > +++ b/arch/powerpc/mm/fault.c > @@ -39,7 +39,7 @@ > #include <asm/uaccess.h> > #include <asm/tlbflush.h> > #include <asm/siginfo.h> > - > +#include <mm/mmu_decl.h> > > #ifdef CONFIG_KPROBES > static inline int notify_page_fault(struct pt_regs *regs) > @@ -243,6 +243,12 @@ good_area: > goto bad_area; > #endif /* CONFIG_6xx */ > #if defined(CONFIG_8xx) > + /* 8xx sometimes need to load a invalid/non-present TLBs. > + * These must be invalidated separately as linux mm don't. > + */ > + if (error_code & 0x40000000) /* no translation? */ > + _tlbil_va(address); arch/powerpc/mm/fault.c:253: error: too few arguments to function ‘_tlbil_va’ -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 0/8] Fix 8xx MMU/TLB. 2009-10-11 16:35 [PATCH 0/8] Fix 8xx MMU/TLB Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund @ 2009-10-14 17:23 ` Scott Wood 2009-10-14 18:46 ` Joakim Tjernlund 1 sibling, 1 reply; 35+ messages in thread From: Scott Wood @ 2009-10-14 17:23 UTC (permalink / raw) To: Joakim Tjernlund; +Cc: Rex Feany, linuxppc-dev On Sun, Oct 11, 2009 at 06:35:04PM +0200, Joakim Tjernlund wrote: > This is the latest batch of mu 8xx MMU/TLB rework. > I think this is complete now and will relax with > other work the next few days. I hope I can get some > testing from Scott and Rex during this time. I applied this stack plus "Remove DIRTY pte handling in DTLB Error" (fixing up conflicts again, as well as the noted build errors), and got this: INIT: version 2.85 booting Mounting /proc and /sys Starting the hotplug events dispatcher udevd udevd[177]: add_to_rules: unknown key 'MODALIAS' in /etc/udev/rules.d/60-pcmcia.rules:4 udevd[177]: add_to_rules: unknown key 'MODALIAS' in /etc/udev/rules.d/60-pcmcia.rules:10 udevd[177]: add_to_rules: unknown key 'MODALIAS' in /etc/udev/rules.d/60-pcmcia.rules:14 Synthesizing initial hotplug events /etc/rc.d/init.d/udev: line 41: 187 Segmentation fault udevsettle --timeout=300 Setting the hostname to 8xx Running depmod WARNING: Couldn't open directory /lib/modules/2.6.31-08384-g2cb4b47-dirty: No such file or directory FATAL: Could not open /lib/modules/2.6.31-08384-g2cb4b47-dirty/modules.dep.tempfor writing: No such file or directory Mounting filesystems BUG: soft lockup - CPU#0 stuck for 61s! [cat:265] NIP: c000f160 LR: c000f160 CTR: 00000007 REGS: c3919c70 TRAP: 0901 Not tainted (2.6.31-08384-g2cb4b47-dirty) MSR: 00009032 <EE,ME,IR,DR> CR: 88008424 XER: 00000000 TASK = c3944bd0[265] 'cat' THREAD: c3918000 GPR00: c000f160 c3919d20 c3944bd0 00000000 100180fc 00000000 00000000 00000001 GPR08: c393e700 00000000 03ca9d21 00000001 48000428 NIP [c000f160] do_page_fault+0x188/0x49c LR [c000f160] do_page_fault+0x188/0x49c Call Trace: [c3919d20] [c000f160] do_page_fault+0x188/0x49c (unreliable) [c3919dd0] [c000e3f0] handle_page_fault+0xc/0x80 [c3919e90] [c008910c] seq_read+0x2a4/0x558 [c3919ee0] [c00ab7c0] proc_reg_read+0x4c/0x70 [c3919ef0] [c006f47c] vfs_read+0xb4/0x158 [c3919f10] [c006f78c] sys_read+0x4c/0x90 [c3919f40] [c000dfc0] ret_from_syscall+0x0/0x38 Instruction dump: 2f990000 419e01f0 801f0014 700a0002 418201f8 7c1900d0 541e0ffe 7fe4fb78 7f85e378 7fc6f378 7f63db78 4804c31d <70690003> 7c601b78 40820230 70690004 -Scott ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 0/8] Fix 8xx MMU/TLB. 2009-10-14 17:23 ` [PATCH 0/8] Fix 8xx MMU/TLB Scott Wood @ 2009-10-14 18:46 ` Joakim Tjernlund 0 siblings, 0 replies; 35+ messages in thread From: Joakim Tjernlund @ 2009-10-14 18:46 UTC (permalink / raw) To: Scott Wood; +Cc: Rex Feany, linuxppc-dev Scott Wood <scottwood@freescale.com> wrote on 14/10/2009 19:23:51: > > On Sun, Oct 11, 2009 at 06:35:04PM +0200, Joakim Tjernlund wrote: > > This is the latest batch of mu 8xx MMU/TLB rework. > > I think this is complete now and will relax with > > other work the next few days. I hope I can get some > > testing from Scott and Rex during this time. > > I applied this stack plus "Remove DIRTY pte handling in DTLB Error" (fixing > up conflicts again, as well as the noted build errors), and got this: Sorry about the build problems, will fixup. Don't know what is causing the error though, works just fine on 2.4 :( Assuming you fixup this error: arch/powerpc/kernel/head_8xx.S:577: undefined reference to `DARfix' with a "b DARFix" I can only guess and I don't have a good guess even :( You could back out 8xx: start using dcbX instructions in various copy routines to see if it is the dcbX insn that is causing the error. > > INIT: version 2.85 booting > Mounting /proc and /sys > Starting the hotplug events dispatcher udevd > udevd[177]: add_to_rules: unknown key 'MODALIAS' in /etc/udev/rules.d/60-pcmcia.rules:4 > udevd[177]: add_to_rules: unknown key 'MODALIAS' in /etc/udev/rules.d/60-pcmcia.rules:10 > udevd[177]: add_to_rules: unknown key 'MODALIAS' in /etc/udev/rules.d/60-pcmcia.rules:14 > Synthesizing initial hotplug events > /etc/rc.d/init.d/udev: line 41: 187 Segmentation fault udevsettle --timeout=300 This looks like the first error? > Setting the hostname to 8xx > Running depmod > WARNING: Couldn't open directory /lib/modules/2.6.31-08384-g2cb4b47-dirty: No > such file or directory > FATAL: Could not open /lib/modules/2.6.31-08384-g2cb4b47-dirty/ > modules.dep.tempfor writing: No such file or directory > Mounting filesystems > BUG: soft lockup - CPU#0 stuck for 61s! [cat:265] Perhaps it is looping on the same TLB Error, caused by dcbX insn? > NIP: c000f160 LR: c000f160 CTR: 00000007 > REGS: c3919c70 TRAP: 0901 Not tainted (2.6.31-08384-g2cb4b47-dirty) > MSR: 00009032 <EE,ME,IR,DR> CR: 88008424 XER: 00000000 > TASK = c3944bd0[265] 'cat' THREAD: c3918000 > GPR00: c000f160 c3919d20 c3944bd0 00000000 100180fc 00000000 00000000 00000001 > GPR08: c393e700 00000000 03ca9d21 00000001 48000428 > NIP [c000f160] do_page_fault+0x188/0x49c > LR [c000f160] do_page_fault+0x188/0x49c > Call Trace: > [c3919d20] [c000f160] do_page_fault+0x188/0x49c (unreliable) > [c3919dd0] [c000e3f0] handle_page_fault+0xc/0x80 > [c3919e90] [c008910c] seq_read+0x2a4/0x558 > [c3919ee0] [c00ab7c0] proc_reg_read+0x4c/0x70 > [c3919ef0] [c006f47c] vfs_read+0xb4/0x158 > [c3919f10] [c006f78c] sys_read+0x4c/0x90 > [c3919f40] [c000dfc0] ret_from_syscall+0x0/0x38 > Instruction dump: > 2f990000 419e01f0 801f0014 700a0002 418201f8 7c1900d0 541e0ffe 7fe4fb78 > 7f85e378 7fc6f378 7f63db78 4804c31d <70690003> 7c601b78 40820230 70690004 > > -Scott > > ^ permalink raw reply [flat|nested] 35+ messages in thread
end of thread, other threads:[~2009-10-14 22:10 UTC | newest] Thread overview: 35+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-10-11 16:35 [PATCH 0/8] Fix 8xx MMU/TLB Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Joakim Tjernlund 2009-10-11 16:35 ` [PATCH 8/8] 8xx: start using dcbX instructions in various copy routines Joakim Tjernlund 2009-10-11 21:26 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Benjamin Herrenschmidt 2009-10-11 22:21 ` Joakim Tjernlund 2009-10-11 22:45 ` Benjamin Herrenschmidt 2009-10-11 21:25 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Benjamin Herrenschmidt 2009-10-11 22:19 ` Joakim Tjernlund 2009-10-11 22:44 ` Benjamin Herrenschmidt 2009-10-12 5:36 ` Joakim Tjernlund 2009-10-12 5:46 ` Benjamin Herrenschmidt 2009-10-12 6:59 ` Joakim Tjernlund 2009-10-14 17:02 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Scott Wood 2009-10-14 17:20 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Scott Wood 2009-10-14 19:05 ` Joakim Tjernlund 2009-10-14 19:23 ` Scott Wood 2009-10-14 20:03 ` Joakim Tjernlund 2009-10-14 20:22 ` Scott Wood 2009-10-14 21:10 ` Joakim Tjernlund 2009-10-14 21:14 ` Scott Wood 2009-10-14 21:17 ` Benjamin Herrenschmidt 2009-10-14 21:41 ` Joakim Tjernlund 2009-10-14 21:52 ` Benjamin Herrenschmidt 2009-10-14 22:09 ` Joakim Tjernlund 2009-10-11 21:25 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Benjamin Herrenschmidt 2009-10-14 16:57 ` Scott Wood 2009-10-14 16:56 ` [PATCH 1/8] 8xx: invalidate non present TLBs Scott Wood 2009-10-14 17:23 ` [PATCH 0/8] Fix 8xx MMU/TLB Scott Wood 2009-10-14 18:46 ` Joakim Tjernlund
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