From 0db46aaabe641e5565238dc3ef7ac2396a0c6286 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 2 Jul 2024 15:51:18 +0200 Subject: [PATCH] powerpc/64e: drop unused TLB miss handlers There are two possibilities for book3e_htw_mode, PPC_HTW_E6500 or PPC_HTW_NONE. The TLB miss handlers are patched to use, respectively: - exc_[data|indstruction]_tlb_miss_e6500_book3e - exc_[data|indstruction]_tlb_miss_bolted_book3e Which means the default handlers are never used. Remove those, and use the bolted handlers (PPC_HTW_NONE) by default. Link: https://lkml.kernel.org/r/9a670adc1771fb1871fba93ace5372f7eadc286f.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman Signed-off-by: Christophe Leroy Cc: Jason Gunthorpe Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Signed-off-by: Andrew Morton --- arch/powerpc/kernel/exceptions-64e.S | 4 +- arch/powerpc/mm/nohash/tlb_64e.c | 4 - arch/powerpc/mm/nohash/tlb_low_64e.S | 226 --------------------------- 3 files changed, 2 insertions(+), 232 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index dcf0591ad3c2..63f6b9f513a4 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -485,8 +485,8 @@ interrupt_base_book3e: /* fake trap */ EXCEPTION_STUB(0x160, decrementer) /* 0x0900 */ EXCEPTION_STUB(0x180, fixed_interval) /* 0x0980 */ EXCEPTION_STUB(0x1a0, watchdog) /* 0x09f0 */ - EXCEPTION_STUB(0x1c0, data_tlb_miss) - EXCEPTION_STUB(0x1e0, instruction_tlb_miss) + EXCEPTION_STUB(0x1c0, data_tlb_miss_bolted) + EXCEPTION_STUB(0x1e0, instruction_tlb_miss_bolted) EXCEPTION_STUB(0x200, altivec_unavailable) EXCEPTION_STUB(0x220, altivec_assist) EXCEPTION_STUB(0x260, perfmon) diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c index 2e894daf4ba7..0eb1e8d99c6d 100644 --- a/arch/powerpc/mm/nohash/tlb_64e.c +++ b/arch/powerpc/mm/nohash/tlb_64e.c @@ -244,10 +244,6 @@ static void __init early_init_mmu_global(void) patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e); patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e); break; - case PPC_HTW_NONE: - patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e); - patch_exception(0x1e0, exc_instruction_tlb_miss_bolted_book3e); - break; } pr_info("MMU: Book3E HW tablewalk %s\n", diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S index b0eb3f7eaed1..a54e7d6c3d0b 100644 --- a/arch/powerpc/mm/nohash/tlb_low_64e.S +++ b/arch/powerpc/mm/nohash/tlb_low_64e.S @@ -511,232 +511,6 @@ itlb_miss_fault_e6500: tlb_epilog_bolted b exc_instruction_storage_book3e -/********************************************************************** - * * - * TLB miss handling for Book3E with TLB reservation and HES support * - * * - **********************************************************************/ - - -/* Data TLB miss */ - START_EXCEPTION(data_tlb_miss) - TLB_MISS_PROLOG - - /* Now we handle the fault proper. We only save DEAR in normal - * fault case since that's the only interesting values here. - * We could probably also optimize by not saving SRR0/1 in the - * linear mapping case but I'll leave that for later - */ - mfspr r14,SPRN_ESR - mfspr r16,SPRN_DEAR /* get faulting address */ - srdi r15,r16,44 /* get region */ - xoris r15,r15,0xc - cmpldi cr0,r15,0 /* linear mapping ? */ - beq tlb_load_linear /* yes -> go to linear map load */ - cmpldi cr1,r15,1 /* vmalloc mapping ? */ - - /* The page tables are mapped virtually linear. At this point, though, - * we don't know whether we are trying to fault in a first level - * virtual address or a virtual page table address. We can get that - * from bit 0x1 of the region ID which we have set for a page table - */ - andis. r10,r15,0x1 - bne- virt_page_table_tlb_miss - - std r14,EX_TLB_ESR(r12); /* save ESR */ - std r16,EX_TLB_DEAR(r12); /* save DEAR */ - - /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */ - li r11,_PAGE_PRESENT - oris r11,r11,_PAGE_ACCESSED@h - - /* We do the user/kernel test for the PID here along with the RW test - */ - srdi. r15,r16,60 /* Check for user region */ - - /* We pre-test some combination of permissions to avoid double - * faults: - * - * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE - * ESR_ST is 0x00800000 - * _PAGE_BAP_SW is 0x00000010 - * So the shift is >> 19. This tests for supervisor writeability. - * If the page happens to be supervisor writeable and not user - * writeable, we will take a new fault later, but that should be - * a rare enough case. - * - * We also move ESR_ST in _PAGE_DIRTY position - * _PAGE_DIRTY is 0x00001000 so the shift is >> 11 - * - * MAS1 is preset for all we need except for TID that needs to - * be cleared for kernel translations - */ - rlwimi r11,r14,32-19,27,27 - rlwimi r11,r14,32-16,19,19 - beq normal_tlb_miss_user - /* XXX replace the RMW cycles with immediate loads + writes */ -1: mfspr r10,SPRN_MAS1 - rlwinm r10,r10,0,16,1 /* Clear TID */ - mtspr SPRN_MAS1,r10 - beq+ cr1,normal_tlb_miss - - /* We got a crappy address, just fault with whatever DEAR and ESR - * are here - */ - TLB_MISS_EPILOG_ERROR - b exc_data_storage_book3e - -/* Instruction TLB miss */ - START_EXCEPTION(instruction_tlb_miss) - TLB_MISS_PROLOG - - /* If we take a recursive fault, the second level handler may need - * to know whether we are handling a data or instruction fault in - * order to get to the right store fault handler. We provide that - * info by writing a crazy value in ESR in our exception frame - */ - li r14,-1 /* store to exception frame is done later */ - - /* Now we handle the fault proper. We only save DEAR in the non - * linear mapping case since we know the linear mapping case will - * not re-enter. We could indeed optimize and also not save SRR0/1 - * in the linear mapping case but I'll leave that for later - * - * Faulting address is SRR0 which is already in r16 - */ - srdi r15,r16,44 /* get region */ - xoris r15,r15,0xc - cmpldi cr0,r15,0 /* linear mapping ? */ - beq tlb_load_linear /* yes -> go to linear map load */ - cmpldi cr1,r15,1 /* vmalloc mapping ? */ - - /* We do the user/kernel test for the PID here along with the RW test - */ - li r11,_PAGE_PRESENT|_PAGE_BAP_UX /* Base perm */ - oris r11,r11,_PAGE_ACCESSED@h - - srdi. r15,r16,60 /* Check for user region */ - std r14,EX_TLB_ESR(r12) /* write crazy -1 to frame */ - beq normal_tlb_miss_user - - li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */ - oris r11,r11,_PAGE_ACCESSED@h - /* XXX replace the RMW cycles with immediate loads + writes */ - mfspr r10,SPRN_MAS1 - rlwinm r10,r10,0,16,1 /* Clear TID */ - mtspr SPRN_MAS1,r10 - beq+ cr1,normal_tlb_miss - - /* We got a crappy address, just fault */ - TLB_MISS_EPILOG_ERROR - b exc_instruction_storage_book3e - -/* - * This is the guts of the first-level TLB miss handler for direct - * misses. We are entered with: - * - * r16 = faulting address - * r15 = region ID - * r14 = crap (free to use) - * r13 = PACA - * r12 = TLB exception frame in PACA - * r11 = PTE permission mask - * r10 = crap (free to use) - */ -normal_tlb_miss_user: -#ifdef CONFIG_PPC_KUAP - mfspr r14,SPRN_MAS1 - rlwinm. r14,r14,0,0x3fff0000 - beq- normal_tlb_miss_access_fault /* KUAP fault */ -#endif -normal_tlb_miss: - /* So we first construct the page table address. We do that by - * shifting the bottom of the address (not the region ID) by - * PAGE_SHIFT-3, clearing the bottom 3 bits (get a PTE ptr) and - * or'ing the fourth high bit. - * - * NOTE: For 64K pages, we do things slightly differently in - * order to handle the weird page table format used by linux - */ - srdi r15,r16,44 - oris r10,r15,0x1 - rldicl r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4 - sldi r15,r10,44 - clrrdi r14,r14,19 - or r10,r15,r14 - - ld r14,0(r10) - -finish_normal_tlb_miss: - /* Check if required permissions are met */ - andc. r15,r11,r14 - bne- normal_tlb_miss_access_fault - - /* Now we build the MAS: - * - * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG - * MAS 1 : Almost fully setup - * - PID already updated by caller if necessary - * - TSIZE need change if !base page size, not - * yet implemented for now - * MAS 2 : Defaults not useful, need to be redone - * MAS 3+7 : Needs to be done - * - * TODO: mix up code below for better scheduling - */ - clrrdi r10,r16,12 /* Clear low crap in EA */ - rlwimi r10,r14,32-19,27,31 /* Insert WIMGE */ - mtspr SPRN_MAS2,r10 - - /* Check page size, if not standard, update MAS1 */ - rldicl r10,r14,64-8,64-8 - cmpldi cr0,r10,BOOK3E_PAGESZ_4K - beq- 1f - mfspr r11,SPRN_MAS1 - rlwimi r11,r14,31,21,24 - rlwinm r11,r11,0,21,19 - mtspr SPRN_MAS1,r11 -1: - /* Move RPN in position */ - rldicr r11,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT - clrldi r15,r11,12 /* Clear crap at the top */ - rlwimi r15,r14,32-8,22,25 /* Move in U bits */ - rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */ - - /* Mask out SW and UW if !DIRTY (XXX optimize this !) */ - andi. r11,r14,_PAGE_DIRTY - bne 1f - li r11,MAS3_SW|MAS3_UW - andc r15,r15,r11 -1: - srdi r16,r15,32 - mtspr SPRN_MAS3,r15 - mtspr SPRN_MAS7,r16 - - tlbwe - -normal_tlb_miss_done: - /* We don't bother with restoring DEAR or ESR since we know we are - * level 0 and just going back to userland. They are only needed - * if you are going to take an access fault - */ - TLB_MISS_EPILOG_SUCCESS - rfi - -normal_tlb_miss_access_fault: - /* We need to check if it was an instruction miss */ - andi. r10,r11,_PAGE_BAP_UX - bne 1f - ld r14,EX_TLB_DEAR(r12) - ld r15,EX_TLB_ESR(r12) - mtspr SPRN_DEAR,r14 - mtspr SPRN_ESR,r15 - TLB_MISS_EPILOG_ERROR - b exc_data_storage_book3e -1: TLB_MISS_EPILOG_ERROR - b exc_instruction_storage_book3e - - /* * This is the guts of the second-level TLB miss handler for direct * misses. We are entered with: