diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/head_fsl_booke.S | 168 |
1 files changed, 44 insertions, 124 deletions
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index c4268500e856..7d554968b635 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -483,90 +483,16 @@ interrupt_base: /* Data Storage Interrupt */ START_EXCEPTION(DataStorage) - mtspr SPRN_SPRG0, r10 /* Save some working registers */ - mtspr SPRN_SPRG1, r11 - mtspr SPRN_SPRG4W, r12 - mtspr SPRN_SPRG5W, r13 - mfcr r11 - mtspr SPRN_SPRG7W, r11 - - /* - * Check if it was a store fault, if not then bail - * because a user tried to access a kernel or - * read-protected page. Otherwise, get the - * offending address and handle it. - */ - mfspr r10, SPRN_ESR - andis. r10, r10, ESR_ST@h - beq 2f - - mfspr r10, SPRN_DEAR /* Get faulting address */ - - /* If we are faulting a kernel address, we have to use the - * kernel page tables. - */ - lis r11, PAGE_OFFSET@h - cmplw 0, r10, r11 - bge 2f - - /* Get the PGD for the current thread */ -3: - mfspr r11,SPRN_SPRG3 - lwz r11,PGDIR(r11) -4: - FIND_PTE - - /* Are _PAGE_USER & _PAGE_RW set & _PAGE_HWWRITE not? */ - andi. r13, r11, _PAGE_RW|_PAGE_USER|_PAGE_HWWRITE - cmpwi 0, r13, _PAGE_RW|_PAGE_USER - bne 2f /* Bail if not */ - - /* Update 'changed'. */ - ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE - stw r11, PTE_FLAGS_OFFSET(r12) /* Update Linux page table */ - - /* MAS2 not updated as the entry does exist in the tlb, this - fault taken to detect state transition (eg: COW -> DIRTY) - */ - andi. r11, r11, _PAGE_HWEXEC - rlwimi r11, r11, 31, 27, 27 /* SX <- _PAGE_HWEXEC */ - ori r11, r11, (MAS3_UW|MAS3_SW|MAS3_UR|MAS3_SR)@l /* set static perms */ - - /* update search PID in MAS6, AS = 0 */ - mfspr r12, SPRN_PID0 - slwi r12, r12, 16 - mtspr SPRN_MAS6, r12 - - /* find the TLB index that caused the fault. It has to be here. */ - tlbsx 0, r10 - - /* only update the perm bits, assume the RPN is fine */ - mfspr r12, SPRN_MAS3 - rlwimi r12, r11, 0, 20, 31 - mtspr SPRN_MAS3,r12 - tlbwe - - /* Done...restore registers and get out of here. */ - mfspr r11, SPRN_SPRG7R - mtcr r11 - mfspr r13, SPRN_SPRG5R - mfspr r12, SPRN_SPRG4R - mfspr r11, SPRN_SPRG1 - mfspr r10, SPRN_SPRG0 - rfi /* Force context change */ - -2: - /* - * The bailout. Restore registers to pre-exception conditions - * and call the heavyweights to help us out. - */ - mfspr r11, SPRN_SPRG7R - mtcr r11 - mfspr r13, SPRN_SPRG5R - mfspr r12, SPRN_SPRG4R - mfspr r11, SPRN_SPRG1 - mfspr r10, SPRN_SPRG0 - b data_access + NORMAL_EXCEPTION_PROLOG + mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */ + stw r5,_ESR(r11) + mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */ + andis. r10,r5,(ESR_ILK|ESR_DLK)@h + bne 1f + EXC_XFER_EE_LITE(0x0300, handle_page_fault) +1: + addi r3,r1,STACK_FRAME_OVERHEAD + EXC_XFER_EE_LITE(0x0300, CacheLockingException) /* Instruction Storage Interrupt */ INSTRUCTION_STORAGE_EXCEPTION @@ -645,15 +571,30 @@ interrupt_base: lwz r11,PGDIR(r11) 4: + /* Mask of required permission bits. Note that while we + * do copy ESR:ST to _PAGE_RW position as trying to write + * to an RO page is pretty common, we don't do it with + * _PAGE_DIRTY. We could do it, but it's a fairly rare + * event so I'd rather take the overhead when it happens + * rather than adding an instruction here. We should measure + * whether the whole thing is worth it in the first place + * as we could avoid loading SPRN_ESR completely in the first + * place... + * + * TODO: Is it worth doing that mfspr & rlwimi in the first + * place or can we save a couple of instructions here ? + */ + mfspr r12,SPRN_ESR + li r13,_PAGE_PRESENT|_PAGE_ACCESSED + rlwimi r13,r12,11,29,29 + FIND_PTE - andi. r13, r11, _PAGE_PRESENT /* Is the page present? */ - beq 2f /* Bail if not present */ + andc. r13,r13,r11 /* Check permission */ + bne 2f /* Bail if permission mismach */ #ifdef CONFIG_PTE_64BIT lwz r13, 0(r12) #endif - ori r11, r11, _PAGE_ACCESSED - stw r11, PTE_FLAGS_OFFSET(r12) /* Jump to common tlb load */ b finish_tlb_load @@ -667,7 +608,7 @@ interrupt_base: mfspr r12, SPRN_SPRG4R mfspr r11, SPRN_SPRG1 mfspr r10, SPRN_SPRG0 - b data_access + b DataStorage /* Instruction TLB Error Interrupt */ /* @@ -705,15 +646,16 @@ interrupt_base: lwz r11,PGDIR(r11) 4: + /* Make up the required permissions */ + li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_HWEXEC + FIND_PTE - andi. r13, r11, _PAGE_PRESENT /* Is the page present? */ - beq 2f /* Bail if not present */ + andc. r13,r13,r11 /* Check permission */ + bne 2f /* Bail if permission mismach */ #ifdef CONFIG_PTE_64BIT lwz r13, 0(r12) #endif - ori r11, r11, _PAGE_ACCESSED - stw r11, PTE_FLAGS_OFFSET(r12) /* Jump to common TLB load point */ b finish_tlb_load @@ -768,29 +710,13 @@ interrupt_base: * Local functions */ - /* - * Data TLB exceptions will bail out to this point - * if they can't resolve the lightweight TLB fault. - */ -data_access: - NORMAL_EXCEPTION_PROLOG - mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */ - stw r5,_ESR(r11) - mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */ - andis. r10,r5,(ESR_ILK|ESR_DLK)@h - bne 1f - EXC_XFER_EE_LITE(0x0300, handle_page_fault) -1: - addi r3,r1,STACK_FRAME_OVERHEAD - EXC_XFER_EE_LITE(0x0300, CacheLockingException) - /* - * Both the instruction and data TLB miss get to this * point to load the TLB. * r10 - EA of fault * r11 - TLB (info from Linux PTE) - * r12, r13 - available to use + * r12 - available to use + * r13 - upper bits of PTE (if PTE_64BIT) or available to use * CR5 - results of addr >= PAGE_OFFSET * MAS0, MAS1 - loaded with proper value when we get here * MAS2, MAS3 - will need additional info from Linux PTE @@ -812,20 +738,14 @@ finish_tlb_load: #endif mtspr SPRN_MAS2, r12 - bge 5, 1f - - /* is user addr */ - andi. r12, r11, (_PAGE_USER | _PAGE_HWWRITE | _PAGE_HWEXEC) + li r10, (_PAGE_HWEXEC | _PAGE_PRESENT) + rlwimi r10, r11, 31, 29, 29 /* extract _PAGE_DIRTY into SW */ + and r12, r11, r10 andi. r10, r11, _PAGE_USER /* Test for _PAGE_USER */ - srwi r10, r12, 1 - or r12, r12, r10 /* Copy user perms into supervisor */ - iseleq r12, 0, r12 - b 2f - - /* is kernel addr */ -1: rlwinm r12, r11, 31, 29, 29 /* Extract _PAGE_HWWRITE into SW */ - ori r12, r12, (MAS3_SX | MAS3_SR) - + slwi r10, r12, 1 + or r10, r10, r12 + iseleq r12, r12, r10 + #ifdef CONFIG_PTE_64BIT 2: rlwimi r12, r13, 24, 0, 7 /* grab RPN[32:39] */ rlwimi r12, r11, 24, 8, 19 /* grab RPN[40:51] */ |