2 * Low level TLB miss handlers for Book3E
4 * Copyright (C) 2008-2009
5 * Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #include <asm/processor.h>
17 #include <asm/ppc_asm.h>
18 #include <asm/asm-offsets.h>
19 #include <asm/cputable.h>
20 #include <asm/pgtable.h>
21 #include <asm/exception-64e.h>
22 #include <asm/ppc-opcode.h>
23 #include <asm/kvm_asm.h>
24 #include <asm/kvm_booke_hv_asm.h>
26 #ifdef CONFIG_PPC_64K_PAGES
27 #define VPTE_PMD_SHIFT (PTE_INDEX_SIZE+1)
29 #define VPTE_PMD_SHIFT (PTE_INDEX_SIZE)
31 #define VPTE_PUD_SHIFT (VPTE_PMD_SHIFT + PMD_INDEX_SIZE)
32 #define VPTE_PGD_SHIFT (VPTE_PUD_SHIFT + PUD_INDEX_SIZE)
33 #define VPTE_INDEX_SIZE (VPTE_PGD_SHIFT + PGD_INDEX_SIZE)
35 /**********************************************************************
37 * TLB miss handling for Book3E with a bolted linear mapping *
38 * No virtual page table, no nested TLB misses *
40 **********************************************************************/
43 * Note that, unlike non-bolted handlers, TLB_EXFRAME is not
44 * modified by the TLB miss handlers themselves, since the TLB miss
45 * handler code will not itself cause a recursive TLB miss.
47 * TLB_EXFRAME will be modified when crit/mc/debug exceptions are
50 .macro tlb_prolog_bolted intnum addr
51 mtspr SPRN_SPRG_GEN_SCRATCH,r12
52 mfspr r12,SPRN_SPRG_TLB_EXFRAME
53 std r13,EX_TLB_R13(r12)
54 std r10,EX_TLB_R10(r12)
55 mfspr r13,SPRN_SPRG_PACA
58 std r11,EX_TLB_R11(r12)
59 #ifdef CONFIG_KVM_BOOKE_HV
62 END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
64 DO_KVM \intnum, SPRN_SRR1
65 std r16,EX_TLB_R16(r12)
66 mfspr r16,\addr /* get faulting address */
67 std r14,EX_TLB_R14(r12)
69 std r15,EX_TLB_R15(r12)
70 std r10,EX_TLB_CR(r12)
74 .macro tlb_epilog_bolted
76 ld r10,EX_TLB_R10(r12)
77 ld r11,EX_TLB_R11(r12)
78 ld r13,EX_TLB_R13(r12)
80 ld r14,EX_TLB_R14(r12)
81 ld r15,EX_TLB_R15(r12)
82 TLB_MISS_RESTORE_STATS
83 ld r16,EX_TLB_R16(r12)
84 mfspr r12,SPRN_SPRG_GEN_SCRATCH
88 START_EXCEPTION(data_tlb_miss_bolted)
89 tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
91 /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */
93 /* We do the user/kernel test for the PID here along with the RW test
95 /* We pre-test some combination of permissions to avoid double
98 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
99 * ESR_ST is 0x00800000
100 * _PAGE_BAP_SW is 0x00000010
101 * So the shift is >> 19. This tests for supervisor writeability.
102 * If the page happens to be supervisor writeable and not user
103 * writeable, we will take a new fault later, but that should be
104 * a rare enough case.
106 * We also move ESR_ST in _PAGE_DIRTY position
107 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
109 * MAS1 is preset for all we need except for TID that needs to
110 * be cleared for kernel translations
115 srdi r15,r16,60 /* get region */
116 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
117 bne- dtlb_miss_fault_bolted /* Bail if fault addr is invalid */
119 rlwinm r10,r11,32-19,27,27
120 rlwimi r10,r11,32-16,19,19
121 cmpwi r15,0 /* user vs kernel check */
122 ori r10,r10,_PAGE_PRESENT
123 oris r11,r10,_PAGE_ACCESSED@h
125 TLB_MISS_STATS_SAVE_INFO_BOLTED
126 bne tlb_miss_kernel_bolted
128 tlb_miss_common_bolted:
130 * This is the guts of the TLB miss handler for bolted-linear.
131 * We are entered with:
133 * r16 = faulting address
134 * r15 = crap (free to use)
135 * r14 = page table base
137 * r11 = PTE permission mask
138 * r10 = crap (free to use)
140 rldicl r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
143 beq tlb_miss_fault_bolted /* No PGDIR, bail */
145 BEGIN_MMU_FTR_SECTION
146 /* Set the TLB reservation and search for existing entry. Then load
149 PPC_TLBSRX_DOT(0,R16)
150 ldx r14,r14,r15 /* grab pgd entry */
151 beq tlb_miss_done_bolted /* tlb exists already, bail */
153 ldx r14,r14,r15 /* grab pgd entry */
154 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
156 #ifndef CONFIG_PPC_64K_PAGES
157 rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
160 bge tlb_miss_fault_bolted /* Bad pgd entry or hugepage; bail */
161 ldx r14,r14,r15 /* grab pud entry */
162 #endif /* CONFIG_PPC_64K_PAGES */
164 rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
167 bge tlb_miss_fault_bolted
168 ldx r14,r14,r15 /* Grab pmd entry */
170 rldicl r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3
173 bge tlb_miss_fault_bolted
174 ldx r14,r14,r15 /* Grab PTE, normal (!huge) page */
176 /* Check if required permissions are met */
178 rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
179 bne- tlb_miss_fault_bolted
181 /* Now we build the MAS:
183 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG
184 * MAS 1 : Almost fully setup
185 * - PID already updated by caller if necessary
186 * - TSIZE need change if !base page size, not
187 * yet implemented for now
188 * MAS 2 : Defaults not useful, need to be redone
189 * MAS 3+7 : Needs to be done
191 clrrdi r11,r16,12 /* Clear low crap in EA */
192 clrldi r15,r15,12 /* Clear crap at the top */
193 rlwimi r11,r14,32-19,27,31 /* Insert WIMGE */
194 rlwimi r15,r14,32-8,22,25 /* Move in U bits */
196 andi. r11,r14,_PAGE_DIRTY
197 rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */
199 /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
201 li r11,MAS3_SW|MAS3_UW
204 mtspr SPRN_MAS7_MAS3,r15
207 tlb_miss_done_bolted:
208 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK)
212 itlb_miss_kernel_bolted:
213 li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */
214 oris r11,r11,_PAGE_ACCESSED@h
215 tlb_miss_kernel_bolted:
217 ld r14,PACA_KERNELPGD(r13)
218 cmpldi cr0,r15,8 /* Check for vmalloc region */
219 rlwinm r10,r10,0,16,1 /* Clear TID */
221 beq+ tlb_miss_common_bolted
223 tlb_miss_fault_bolted:
224 /* We need to check if it was an instruction miss */
225 andi. r10,r11,_PAGE_EXEC|_PAGE_BAP_SX
226 bne itlb_miss_fault_bolted
227 dtlb_miss_fault_bolted:
228 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
230 b exc_data_storage_book3e
231 itlb_miss_fault_bolted:
232 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
234 b exc_instruction_storage_book3e
236 /* Instruction TLB miss */
237 START_EXCEPTION(instruction_tlb_miss_bolted)
238 tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
240 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
241 srdi r15,r16,60 /* get region */
242 TLB_MISS_STATS_SAVE_INFO_BOLTED
243 bne- itlb_miss_fault_bolted
245 li r11,_PAGE_PRESENT|_PAGE_EXEC /* Base perm */
247 /* We do the user/kernel test for the PID here along with the RW test
250 cmpldi cr0,r15,0 /* Check for user region */
251 oris r11,r11,_PAGE_ACCESSED@h
252 beq tlb_miss_common_bolted
253 b itlb_miss_kernel_bolted
255 #ifdef CONFIG_PPC_FSL_BOOK3E
257 * TLB miss handling for e6500 and derivatives, using hardware tablewalk.
259 * Linear mapping is bolted: no virtual page table or nested TLB misses
260 * Indirect entries in TLB1, hardware loads resulting direct entries
262 * No HES or NV hint on TLB1, so we need to do software round-robin
263 * No tlbsrx. so we need a spinlock, and we have to deal
264 * with MAS-damage caused by tlbsx
268 START_EXCEPTION(instruction_tlb_miss_e6500)
269 tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
271 ld r11,PACA_TCD_PTR(r13)
272 srdi. r15,r16,60 /* get region */
275 TLB_MISS_STATS_SAVE_INFO_BOLTED
276 bne tlb_miss_kernel_e6500 /* user/kernel test */
278 b tlb_miss_common_e6500
280 START_EXCEPTION(data_tlb_miss_e6500)
281 tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
283 ld r11,PACA_TCD_PTR(r13)
284 srdi. r15,r16,60 /* get region */
287 TLB_MISS_STATS_SAVE_INFO_BOLTED
288 bne tlb_miss_kernel_e6500 /* user vs kernel check */
291 * This is the guts of the TLB miss handler for e6500 and derivatives.
292 * We are entered with:
294 * r16 = page of faulting address (low bit 0 if data, 1 if instruction)
295 * r15 = crap (free to use)
296 * r14 = page table base
298 * r11 = tlb_per_core ptr
301 tlb_miss_common_e6500:
303 * Search if we already have an indirect entry for that virtual
304 * address, and if we do, bail out.
306 * MAS6:IND should be already set based on MAS4
309 lhz r10,PACAPACAINDEX(r13)
311 cmpdi cr1,r15,1 /* set cr1.eq = 0 for non-recursive */
317 2: cmpd cr1,r15,r10 /* recursive lock due to mcheck/crit/etc? */
318 beq cr1,3b /* unlock will happen if cr1.eq = 0 */
333 andis. r10,r10,MAS1_VALID@h
334 bne tlb_miss_done_e6500
336 /* Now, we need to walk the page tables. First check if we are in
339 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
340 bne- tlb_miss_fault_e6500
342 rldicl r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
345 beq- tlb_miss_fault_e6500 /* No PGDIR, bail */
346 ldx r14,r14,r15 /* grab pgd entry */
348 rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
351 bge tlb_miss_fault_e6500 /* Bad pgd entry or hugepage; bail */
352 ldx r14,r14,r15 /* grab pud entry */
354 rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
357 bge tlb_miss_fault_e6500
358 ldx r14,r14,r15 /* Grab pmd entry */
362 bge tlb_miss_fault_e6500
364 /* Now we build the MAS for a 2M indirect page:
366 * MAS 0 : ESEL needs to be filled by software round-robin
367 * MAS 1 : Fully set up
368 * - PID already updated by caller if necessary
369 * - TSIZE for now is base ind page size always
370 * - TID already cleared if necessary
371 * MAS 2 : Default not 2M-aligned, need to be redone
372 * MAS 3+7 : Needs to be done
375 ori r14,r14,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
376 mtspr SPRN_MAS7_MAS3,r14
378 clrrdi r15,r16,21 /* make EA 2M-aligned */
381 lbz r15,TCD_ESEL_NEXT(r11)
382 lbz r16,TCD_ESEL_MAX(r11)
383 lbz r14,TCD_ESEL_FIRST(r11)
384 rlwimi r10,r15,16,0x00ff0000 /* insert esel_next into MAS0 */
385 addi r15,r15,1 /* increment esel_next */
388 iseleq r15,r14,r15 /* if next == last use first */
389 stb r15,TCD_ESEL_NEXT(r11)
394 .macro tlb_unlock_e6500
395 beq cr1,1f /* no unlock if lock was recursively grabbed */
403 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK)
407 tlb_miss_kernel_e6500:
409 ld r14,PACA_KERNELPGD(r13)
410 cmpldi cr0,r15,8 /* Check for vmalloc region */
411 rlwinm r10,r10,0,16,1 /* Clear TID */
413 beq+ tlb_miss_common_e6500
415 tlb_miss_fault_e6500:
417 /* We need to check if it was an instruction miss */
419 bne itlb_miss_fault_e6500
420 dtlb_miss_fault_e6500:
421 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
423 b exc_data_storage_book3e
424 itlb_miss_fault_e6500:
425 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
427 b exc_instruction_storage_book3e
428 #endif /* CONFIG_PPC_FSL_BOOK3E */
430 /**********************************************************************
432 * TLB miss handling for Book3E with TLB reservation and HES support *
434 **********************************************************************/
438 START_EXCEPTION(data_tlb_miss)
441 /* Now we handle the fault proper. We only save DEAR in normal
442 * fault case since that's the only interesting values here.
443 * We could probably also optimize by not saving SRR0/1 in the
444 * linear mapping case but I'll leave that for later
447 mfspr r16,SPRN_DEAR /* get faulting address */
448 srdi r15,r16,60 /* get region */
449 cmpldi cr0,r15,0xc /* linear mapping ? */
450 TLB_MISS_STATS_SAVE_INFO
451 beq tlb_load_linear /* yes -> go to linear map load */
453 /* The page tables are mapped virtually linear. At this point, though,
454 * we don't know whether we are trying to fault in a first level
455 * virtual address or a virtual page table address. We can get that
456 * from bit 0x1 of the region ID which we have set for a page table
459 bne- virt_page_table_tlb_miss
461 std r14,EX_TLB_ESR(r12); /* save ESR */
462 std r16,EX_TLB_DEAR(r12); /* save DEAR */
464 /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */
466 oris r11,r11,_PAGE_ACCESSED@h
468 /* We do the user/kernel test for the PID here along with the RW test
470 cmpldi cr0,r15,0 /* Check for user region */
472 /* We pre-test some combination of permissions to avoid double
475 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
476 * ESR_ST is 0x00800000
477 * _PAGE_BAP_SW is 0x00000010
478 * So the shift is >> 19. This tests for supervisor writeability.
479 * If the page happens to be supervisor writeable and not user
480 * writeable, we will take a new fault later, but that should be
481 * a rare enough case.
483 * We also move ESR_ST in _PAGE_DIRTY position
484 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
486 * MAS1 is preset for all we need except for TID that needs to
487 * be cleared for kernel translations
489 rlwimi r11,r14,32-19,27,27
490 rlwimi r11,r14,32-16,19,19
492 /* XXX replace the RMW cycles with immediate loads + writes */
493 1: mfspr r10,SPRN_MAS1
494 cmpldi cr0,r15,8 /* Check for vmalloc region */
495 rlwinm r10,r10,0,16,1 /* Clear TID */
499 /* We got a crappy address, just fault with whatever DEAR and ESR
502 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
503 TLB_MISS_EPILOG_ERROR
504 b exc_data_storage_book3e
506 /* Instruction TLB miss */
507 START_EXCEPTION(instruction_tlb_miss)
510 /* If we take a recursive fault, the second level handler may need
511 * to know whether we are handling a data or instruction fault in
512 * order to get to the right store fault handler. We provide that
513 * info by writing a crazy value in ESR in our exception frame
515 li r14,-1 /* store to exception frame is done later */
517 /* Now we handle the fault proper. We only save DEAR in the non
518 * linear mapping case since we know the linear mapping case will
519 * not re-enter. We could indeed optimize and also not save SRR0/1
520 * in the linear mapping case but I'll leave that for later
522 * Faulting address is SRR0 which is already in r16
524 srdi r15,r16,60 /* get region */
525 cmpldi cr0,r15,0xc /* linear mapping ? */
526 TLB_MISS_STATS_SAVE_INFO
527 beq tlb_load_linear /* yes -> go to linear map load */
529 /* We do the user/kernel test for the PID here along with the RW test
531 li r11,_PAGE_PRESENT|_PAGE_EXEC /* Base perm */
532 oris r11,r11,_PAGE_ACCESSED@h
534 cmpldi cr0,r15,0 /* Check for user region */
535 std r14,EX_TLB_ESR(r12) /* write crazy -1 to frame */
538 li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */
539 oris r11,r11,_PAGE_ACCESSED@h
540 /* XXX replace the RMW cycles with immediate loads + writes */
542 cmpldi cr0,r15,8 /* Check for vmalloc region */
543 rlwinm r10,r10,0,16,1 /* Clear TID */
547 /* We got a crappy address, just fault */
548 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
549 TLB_MISS_EPILOG_ERROR
550 b exc_instruction_storage_book3e
553 * This is the guts of the first-level TLB miss handler for direct
554 * misses. We are entered with:
556 * r16 = faulting address
558 * r14 = crap (free to use)
560 * r12 = TLB exception frame in PACA
561 * r11 = PTE permission mask
562 * r10 = crap (free to use)
565 /* So we first construct the page table address. We do that by
566 * shifting the bottom of the address (not the region ID) by
567 * PAGE_SHIFT-3, clearing the bottom 3 bits (get a PTE ptr) and
568 * or'ing the fourth high bit.
570 * NOTE: For 64K pages, we do things slightly differently in
571 * order to handle the weird page table format used by linux
574 #ifdef CONFIG_PPC_64K_PAGES
575 /* For the top bits, 16 bytes per PTE */
576 rldicl r14,r16,64-(PAGE_SHIFT-4),PAGE_SHIFT-4+4
577 /* Now create the bottom bits as 0 in position 0x8000 and
578 * the rest calculated for 8 bytes per PTE
580 rldicl r15,r16,64-(PAGE_SHIFT-3),64-15
581 /* Insert the bottom bits in */
582 rlwimi r14,r15,0,16,31
584 rldicl r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4
590 BEGIN_MMU_FTR_SECTION
591 /* Set the TLB reservation and search for existing entry. Then load
594 PPC_TLBSRX_DOT(0,R16)
596 beq normal_tlb_miss_done
599 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
601 finish_normal_tlb_miss:
602 /* Check if required permissions are met */
604 bne- normal_tlb_miss_access_fault
606 /* Now we build the MAS:
608 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG
609 * MAS 1 : Almost fully setup
610 * - PID already updated by caller if necessary
611 * - TSIZE need change if !base page size, not
612 * yet implemented for now
613 * MAS 2 : Defaults not useful, need to be redone
614 * MAS 3+7 : Needs to be done
616 * TODO: mix up code below for better scheduling
618 clrrdi r11,r16,12 /* Clear low crap in EA */
619 rlwimi r11,r14,32-19,27,31 /* Insert WIMGE */
622 /* Check page size, if not standard, update MAS1 */
623 rldicl r11,r14,64-8,64-8
624 #ifdef CONFIG_PPC_64K_PAGES
625 cmpldi cr0,r11,BOOK3E_PAGESZ_64K
627 cmpldi cr0,r11,BOOK3E_PAGESZ_4K
631 rlwimi r11,r14,31,21,24
632 rlwinm r11,r11,0,21,19
635 /* Move RPN in position */
636 rldicr r11,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
637 clrldi r15,r11,12 /* Clear crap at the top */
638 rlwimi r15,r14,32-8,22,25 /* Move in U bits */
639 rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */
641 /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
642 andi. r11,r14,_PAGE_DIRTY
644 li r11,MAS3_SW|MAS3_UW
647 BEGIN_MMU_FTR_SECTION
652 mtspr SPRN_MAS7_MAS3,r15
653 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
657 normal_tlb_miss_done:
658 /* We don't bother with restoring DEAR or ESR since we know we are
659 * level 0 and just going back to userland. They are only needed
660 * if you are going to take an access fault
662 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK)
663 TLB_MISS_EPILOG_SUCCESS
666 normal_tlb_miss_access_fault:
667 /* We need to check if it was an instruction miss */
668 andi. r10,r11,_PAGE_EXEC
670 ld r14,EX_TLB_DEAR(r12)
671 ld r15,EX_TLB_ESR(r12)
674 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
675 TLB_MISS_EPILOG_ERROR
676 b exc_data_storage_book3e
677 1: TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
678 TLB_MISS_EPILOG_ERROR
679 b exc_instruction_storage_book3e
683 * This is the guts of the second-level TLB miss handler for direct
684 * misses. We are entered with:
686 * r16 = virtual page table faulting address
687 * r15 = region (top 4 bits of address)
688 * r14 = crap (free to use)
690 * r12 = TLB exception frame in PACA
691 * r11 = crap (free to use)
692 * r10 = crap (free to use)
694 * Note that this should only ever be called as a second level handler
695 * with the current scheme when using SW load.
696 * That means we can always get the original fault DEAR at
697 * EX_TLB_DEAR-EX_TLB_SIZE(r12)
699 * It can be re-entered by the linear mapping miss handler. However, to
700 * avoid too much complication, it will restart the whole fault at level
701 * 0 so we don't care too much about clobbers
703 * XXX That code was written back when we couldn't clobber r14. We can now,
704 * so we could probably optimize things a bit
706 virt_page_table_tlb_miss:
707 /* Are we hitting a kernel page table ? */
710 /* The cool thing now is that r10 contains 0 for user and 8 for kernel,
711 * and we happen to have the swapper_pg_dir at offset 8 from the user
712 * pgdir in the PACA :-).
716 /* If kernel, we need to clear MAS1 TID */
718 /* XXX replace the RMW cycles with immediate loads + writes */
720 rlwinm r10,r10,0,16,1 /* Clear TID */
723 BEGIN_MMU_FTR_SECTION
724 /* Search if we already have a TLB entry for that virtual address, and
725 * if we do, bail out.
727 PPC_TLBSRX_DOT(0,R16)
728 beq virt_page_table_tlb_miss_done
729 END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
731 /* Now, we need to walk the page tables. First check if we are in
734 rldicl. r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4
735 bne- virt_page_table_tlb_miss_fault
737 /* Get the PGD pointer */
740 beq- virt_page_table_tlb_miss_fault
742 /* Get to PGD entry */
743 rldicl r11,r16,64-VPTE_PGD_SHIFT,64-PGD_INDEX_SIZE-3
747 bge virt_page_table_tlb_miss_fault
749 #ifndef CONFIG_PPC_64K_PAGES
750 /* Get to PUD entry */
751 rldicl r11,r16,64-VPTE_PUD_SHIFT,64-PUD_INDEX_SIZE-3
755 bge virt_page_table_tlb_miss_fault
756 #endif /* CONFIG_PPC_64K_PAGES */
758 /* Get to PMD entry */
759 rldicl r11,r16,64-VPTE_PMD_SHIFT,64-PMD_INDEX_SIZE-3
763 bge virt_page_table_tlb_miss_fault
765 /* Ok, we're all right, we can now create a kernel translation for
766 * a 4K or 64K page from r16 -> r15.
768 /* Now we build the MAS:
770 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG
771 * MAS 1 : Almost fully setup
772 * - PID already updated by caller if necessary
773 * - TSIZE for now is base page size always
774 * MAS 2 : Use defaults
775 * MAS 3+7 : Needs to be done
777 * So we only do MAS 2 and 3 for now...
779 clrldi r11,r15,4 /* remove region ID from RPN */
780 ori r10,r11,1 /* Or-in SR */
782 BEGIN_MMU_FTR_SECTION
787 mtspr SPRN_MAS7_MAS3,r10
788 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
792 BEGIN_MMU_FTR_SECTION
793 virt_page_table_tlb_miss_done:
795 /* We have overriden MAS2:EPN but currently our primary TLB miss
796 * handler will always restore it so that should not be an issue,
797 * if we ever optimize the primary handler to not write MAS2 on
798 * some cases, we'll have to restore MAS2:EPN here based on the
799 * original fault's DEAR. If we do that we have to modify the
800 * ITLB miss handler to also store SRR0 in the exception frame
803 * However, one nasty thing we did is we cleared the reservation
804 * (well, potentially we did). We do a trick here thus if we
805 * are not a level 0 exception (we interrupted the TLB miss) we
806 * offset the return address by -4 in order to replay the tlbsrx
810 cmpldi cr0,r10,PACA_EXTLB+EX_TLB_SIZE
812 ld r11,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
814 std r10,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
816 END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
817 /* Return to caller, normal case */
818 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_OK);
819 TLB_MISS_EPILOG_SUCCESS
822 virt_page_table_tlb_miss_fault:
823 /* If we fault here, things are a little bit tricky. We need to call
824 * either data or instruction store fault, and we need to retrieve
825 * the original fault address and ESR (for data).
827 * The thing is, we know that in normal circumstances, this is
828 * always called as a second level tlb miss for SW load or as a first
829 * level TLB miss for HW load, so we should be able to peek at the
830 * relevant information in the first exception frame in the PACA.
832 * However, we do need to double check that, because we may just hit
833 * a stray kernel pointer or a userland attack trying to hit those
834 * areas. If that is the case, we do a data fault. (We can't get here
835 * from an instruction tlb miss anyway).
837 * Note also that when going to a fault, we must unwind the previous
838 * level as well. Since we are doing that, we don't need to clear or
839 * restore the TLB reservation neither.
842 cmpldi cr0,r10,PACA_EXTLB+EX_TLB_SIZE
843 bne- virt_page_table_tlb_miss_whacko_fault
845 /* We dig the original DEAR and ESR from slot 0 */
846 ld r15,EX_TLB_DEAR+PACA_EXTLB(r13)
847 ld r16,EX_TLB_ESR+PACA_EXTLB(r13)
849 /* We check for the "special" ESR value for instruction faults */
854 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_PT_FAULT);
855 TLB_MISS_EPILOG_ERROR
856 b exc_data_storage_book3e
857 1: TLB_MISS_STATS_I(MMSTAT_TLB_MISS_PT_FAULT);
858 TLB_MISS_EPILOG_ERROR
859 b exc_instruction_storage_book3e
861 virt_page_table_tlb_miss_whacko_fault:
862 /* The linear fault will restart everything so ESR and DEAR will
863 * not have been clobbered, let's just fault with what we have
865 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_FAULT);
866 TLB_MISS_EPILOG_ERROR
867 b exc_data_storage_book3e
870 /**************************************************************
872 * TLB miss handling for Book3E with hw page table support *
874 **************************************************************/
878 START_EXCEPTION(data_tlb_miss_htw)
881 /* Now we handle the fault proper. We only save DEAR in normal
882 * fault case since that's the only interesting values here.
883 * We could probably also optimize by not saving SRR0/1 in the
884 * linear mapping case but I'll leave that for later
887 mfspr r16,SPRN_DEAR /* get faulting address */
888 srdi r11,r16,60 /* get region */
889 cmpldi cr0,r11,0xc /* linear mapping ? */
890 TLB_MISS_STATS_SAVE_INFO
891 beq tlb_load_linear /* yes -> go to linear map load */
893 /* We do the user/kernel test for the PID here along with the RW test
895 cmpldi cr0,r11,0 /* Check for user region */
896 ld r15,PACAPGD(r13) /* Load user pgdir */
899 /* XXX replace the RMW cycles with immediate loads + writes */
900 1: mfspr r10,SPRN_MAS1
901 cmpldi cr0,r11,8 /* Check for vmalloc region */
902 rlwinm r10,r10,0,16,1 /* Clear TID */
904 ld r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */
907 /* We got a crappy address, just fault with whatever DEAR and ESR
910 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
911 TLB_MISS_EPILOG_ERROR
912 b exc_data_storage_book3e
914 /* Instruction TLB miss */
915 START_EXCEPTION(instruction_tlb_miss_htw)
918 /* If we take a recursive fault, the second level handler may need
919 * to know whether we are handling a data or instruction fault in
920 * order to get to the right store fault handler. We provide that
921 * info by keeping a crazy value for ESR in r14
923 li r14,-1 /* store to exception frame is done later */
925 /* Now we handle the fault proper. We only save DEAR in the non
926 * linear mapping case since we know the linear mapping case will
927 * not re-enter. We could indeed optimize and also not save SRR0/1
928 * in the linear mapping case but I'll leave that for later
930 * Faulting address is SRR0 which is already in r16
932 srdi r11,r16,60 /* get region */
933 cmpldi cr0,r11,0xc /* linear mapping ? */
934 TLB_MISS_STATS_SAVE_INFO
935 beq tlb_load_linear /* yes -> go to linear map load */
937 /* We do the user/kernel test for the PID here along with the RW test
939 cmpldi cr0,r11,0 /* Check for user region */
940 ld r15,PACAPGD(r13) /* Load user pgdir */
943 /* XXX replace the RMW cycles with immediate loads + writes */
944 1: mfspr r10,SPRN_MAS1
945 cmpldi cr0,r11,8 /* Check for vmalloc region */
946 rlwinm r10,r10,0,16,1 /* Clear TID */
948 ld r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */
951 /* We got a crappy address, just fault */
952 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
953 TLB_MISS_EPILOG_ERROR
954 b exc_instruction_storage_book3e
958 * This is the guts of the second-level TLB miss handler for direct
959 * misses. We are entered with:
961 * r16 = virtual page table faulting address
965 * r12 = TLB exception frame in PACA
966 * r11 = crap (free to use)
967 * r10 = crap (free to use)
969 * It can be re-entered by the linear mapping miss handler. However, to
970 * avoid too much complication, it will save/restore things for us
973 /* Search if we already have a TLB entry for that virtual address, and
974 * if we do, bail out.
976 * MAS1:IND should be already set based on MAS4
978 PPC_TLBSRX_DOT(0,R16)
979 beq htw_tlb_miss_done
981 /* Now, we need to walk the page tables. First check if we are in
984 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
985 bne- htw_tlb_miss_fault
987 /* Get the PGD pointer */
989 beq- htw_tlb_miss_fault
991 /* Get to PGD entry */
992 rldicl r11,r16,64-(PGDIR_SHIFT-3),64-PGD_INDEX_SIZE-3
996 bge htw_tlb_miss_fault
998 #ifndef CONFIG_PPC_64K_PAGES
999 /* Get to PUD entry */
1000 rldicl r11,r16,64-(PUD_SHIFT-3),64-PUD_INDEX_SIZE-3
1004 bge htw_tlb_miss_fault
1005 #endif /* CONFIG_PPC_64K_PAGES */
1007 /* Get to PMD entry */
1008 rldicl r11,r16,64-(PMD_SHIFT-3),64-PMD_INDEX_SIZE-3
1012 bge htw_tlb_miss_fault
1014 /* Ok, we're all right, we can now create an indirect entry for
1015 * a 1M or 256M page.
1017 * The last trick is now that because we use "half" pages for
1018 * the HTW (1M IND is 2K and 256M IND is 32K) we need to account
1019 * for an added LSB bit to the RPN. For 64K pages, there is no
1020 * problem as we already use 32K arrays (half PTE pages), but for
1021 * 4K page we need to extract a bit from the virtual address and
1022 * insert it into the "PA52" bit of the RPN.
1024 #ifndef CONFIG_PPC_64K_PAGES
1025 rlwimi r15,r16,32-9,20,20
1027 /* Now we build the MAS:
1029 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG
1030 * MAS 1 : Almost fully setup
1031 * - PID already updated by caller if necessary
1032 * - TSIZE for now is base ind page size always
1033 * MAS 2 : Use defaults
1034 * MAS 3+7 : Needs to be done
1036 #ifdef CONFIG_PPC_64K_PAGES
1037 ori r10,r15,(BOOK3E_PAGESZ_64K << MAS3_SPSIZE_SHIFT)
1039 ori r10,r15,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
1042 BEGIN_MMU_FTR_SECTION
1046 MMU_FTR_SECTION_ELSE
1047 mtspr SPRN_MAS7_MAS3,r10
1048 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
1053 /* We don't bother with restoring DEAR or ESR since we know we are
1054 * level 0 and just going back to userland. They are only needed
1055 * if you are going to take an access fault
1057 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_OK)
1058 TLB_MISS_EPILOG_SUCCESS
1062 /* We need to check if it was an instruction miss. We know this
1063 * though because r14 would contain -1
1069 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_PT_FAULT)
1070 TLB_MISS_EPILOG_ERROR
1071 b exc_data_storage_book3e
1072 1: TLB_MISS_STATS_I(MMSTAT_TLB_MISS_PT_FAULT)
1073 TLB_MISS_EPILOG_ERROR
1074 b exc_instruction_storage_book3e
1077 * This is the guts of "any" level TLB miss handler for kernel linear
1078 * mapping misses. We are entered with:
1081 * r16 = faulting address
1082 * r15 = crap (free to use)
1083 * r14 = ESR (data) or -1 (instruction)
1085 * r12 = TLB exception frame in PACA
1086 * r11 = crap (free to use)
1087 * r10 = crap (free to use)
1089 * In addition we know that we will not re-enter, so in theory, we could
1090 * use a simpler epilog not restoring SRR0/1 etc.. but we'll do that later.
1092 * We also need to be careful about MAS registers here & TLB reservation,
1093 * as we know we'll have clobbered them if we interrupt the main TLB miss
1094 * handlers in which case we probably want to do a full restart at level
1095 * 0 rather than saving / restoring the MAS.
1097 * Note: If we care about performance of that core, we can easily shuffle
1098 * a few things around
1101 /* For now, we assume the linear mapping is contiguous and stops at
1102 * linear_map_top. We also assume the size is a multiple of 1G, thus
1103 * we only use 1G pages for now. That might have to be changed in a
1104 * final implementation, especially when dealing with hypervisors
1107 ld r11,linear_map_top@got(r11)
1111 bge tlb_load_linear_fault
1113 /* MAS1 need whole new setup. */
1114 li r15,(BOOK3E_PAGESZ_1GB<<MAS1_TSIZE_SHIFT)
1115 oris r15,r15,MAS1_VALID@h /* MAS1 needs V and TSIZE */
1118 /* Already somebody there ? */
1119 PPC_TLBSRX_DOT(0,R16)
1120 beq tlb_load_linear_done
1122 /* Now we build the remaining MAS. MAS0 and 2 should be fine
1123 * with their defaults, which leaves us with MAS 3 and 7. The
1124 * mapping is linear, so we just take the address, clear the
1125 * region bits, and or in the permission bits which are currently
1128 clrrdi r10,r16,30 /* 1G page index */
1129 clrldi r10,r10,4 /* clear region bits */
1130 ori r10,r10,MAS3_SR|MAS3_SW|MAS3_SX
1132 BEGIN_MMU_FTR_SECTION
1136 MMU_FTR_SECTION_ELSE
1137 mtspr SPRN_MAS7_MAS3,r10
1138 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
1142 tlb_load_linear_done:
1143 /* We use the "error" epilog for success as we do want to
1144 * restore to the initial faulting context, whatever it was.
1145 * We do that because we can't resume a fault within a TLB
1146 * miss handler, due to MAS and TLB reservation being clobbered.
1148 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_LINEAR)
1149 TLB_MISS_EPILOG_ERROR
1152 tlb_load_linear_fault:
1153 /* We keep the DEAR and ESR around, this shouldn't have happened */
1156 TLB_MISS_EPILOG_ERROR_SPECIAL
1157 b exc_data_storage_book3e
1158 1: TLB_MISS_EPILOG_ERROR_SPECIAL
1159 b exc_instruction_storage_book3e
1162 #ifdef CONFIG_BOOK3E_MMU_TLB_STATS