1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * Low level TLB miss handlers for Book3E 4 * 5 * Copyright (C) 2008-2009 6 * Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp. 7 */ 8 9#include <linux/pgtable.h> 10#include <asm/processor.h> 11#include <asm/reg.h> 12#include <asm/page.h> 13#include <asm/mmu.h> 14#include <asm/ppc_asm.h> 15#include <asm/asm-offsets.h> 16#include <asm/cputable.h> 17#include <asm/exception-64e.h> 18#include <asm/ppc-opcode.h> 19#include <asm/kvm_asm.h> 20#include <asm/kvm_booke_hv_asm.h> 21#include <asm/feature-fixups.h> 22 23#define VPTE_PMD_SHIFT (PTE_INDEX_SIZE) 24#define VPTE_PUD_SHIFT (VPTE_PMD_SHIFT + PMD_INDEX_SIZE) 25#define VPTE_PGD_SHIFT (VPTE_PUD_SHIFT + PUD_INDEX_SIZE) 26#define VPTE_INDEX_SIZE (VPTE_PGD_SHIFT + PGD_INDEX_SIZE) 27 28/********************************************************************** 29 * * 30 * TLB miss handling for Book3E with a bolted linear mapping * 31 * No virtual page table, no nested TLB misses * 32 * * 33 **********************************************************************/ 34 35/* 36 * Note that, unlike non-bolted handlers, TLB_EXFRAME is not 37 * modified by the TLB miss handlers themselves, since the TLB miss 38 * handler code will not itself cause a recursive TLB miss. 39 * 40 * TLB_EXFRAME will be modified when crit/mc/debug exceptions are 41 * entered/exited. 42 */ 43.macro tlb_prolog_bolted intnum addr 44 mtspr SPRN_SPRG_GEN_SCRATCH,r12 45 mfspr r12,SPRN_SPRG_TLB_EXFRAME 46 std r13,EX_TLB_R13(r12) 47 std r10,EX_TLB_R10(r12) 48 mfspr r13,SPRN_SPRG_PACA 49 50 mfcr r10 51 std r11,EX_TLB_R11(r12) 52#ifdef CONFIG_KVM_BOOKE_HV 53BEGIN_FTR_SECTION 54 mfspr r11, SPRN_SRR1 55END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV) 56#endif 57 DO_KVM \intnum, SPRN_SRR1 58 std r16,EX_TLB_R16(r12) 59 mfspr r16,\addr /* get faulting address */ 60 std r14,EX_TLB_R14(r12) 61 ld r14,PACAPGD(r13) 62 std r15,EX_TLB_R15(r12) 63 std r10,EX_TLB_CR(r12) 64#ifdef CONFIG_PPC_FSL_BOOK3E 65START_BTB_FLUSH_SECTION 66 mfspr r11, SPRN_SRR1 67 andi. r10,r11,MSR_PR 68 beq 1f 69 BTB_FLUSH(r10) 701: 71END_BTB_FLUSH_SECTION 72 std r7,EX_TLB_R7(r12) 73#endif 74 TLB_MISS_PROLOG_STATS 75.endm 76 77.macro tlb_epilog_bolted 78 ld r14,EX_TLB_CR(r12) 79#ifdef CONFIG_PPC_FSL_BOOK3E 80 ld r7,EX_TLB_R7(r12) 81#endif 82 ld r10,EX_TLB_R10(r12) 83 ld r11,EX_TLB_R11(r12) 84 ld r13,EX_TLB_R13(r12) 85 mtcr r14 86 ld r14,EX_TLB_R14(r12) 87 ld r15,EX_TLB_R15(r12) 88 TLB_MISS_RESTORE_STATS 89 ld r16,EX_TLB_R16(r12) 90 mfspr r12,SPRN_SPRG_GEN_SCRATCH 91.endm 92 93/* Data TLB miss */ 94 START_EXCEPTION(data_tlb_miss_bolted) 95 tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR 96 97 /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */ 98 99 /* We do the user/kernel test for the PID here along with the RW test 100 */ 101 /* We pre-test some combination of permissions to avoid double 102 * faults: 103 * 104 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE 105 * ESR_ST is 0x00800000 106 * _PAGE_BAP_SW is 0x00000010 107 * So the shift is >> 19. This tests for supervisor writeability. 108 * If the page happens to be supervisor writeable and not user 109 * writeable, we will take a new fault later, but that should be 110 * a rare enough case. 111 * 112 * We also move ESR_ST in _PAGE_DIRTY position 113 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11 114 * 115 * MAS1 is preset for all we need except for TID that needs to 116 * be cleared for kernel translations 117 */ 118 119 mfspr r11,SPRN_ESR 120 121 srdi r15,r16,60 /* get region */ 122 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4 123 bne- dtlb_miss_fault_bolted /* Bail if fault addr is invalid */ 124 125 rlwinm r10,r11,32-19,27,27 126 rlwimi r10,r11,32-16,19,19 127 cmpwi r15,0 /* user vs kernel check */ 128 ori r10,r10,_PAGE_PRESENT 129 oris r11,r10,_PAGE_ACCESSED@h 130 131 TLB_MISS_STATS_SAVE_INFO_BOLTED 132 bne tlb_miss_kernel_bolted 133 134tlb_miss_common_bolted: 135/* 136 * This is the guts of the TLB miss handler for bolted-linear. 137 * We are entered with: 138 * 139 * r16 = faulting address 140 * r15 = crap (free to use) 141 * r14 = page table base 142 * r13 = PACA 143 * r11 = PTE permission mask 144 * r10 = crap (free to use) 145 */ 146 rldicl r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3 147 cmpldi cr0,r14,0 148 clrrdi r15,r15,3 149 beq tlb_miss_fault_bolted /* No PGDIR, bail */ 150 151BEGIN_MMU_FTR_SECTION 152 /* Set the TLB reservation and search for existing entry. Then load 153 * the entry. 154 */ 155 PPC_TLBSRX_DOT(0,R16) 156 ldx r14,r14,r15 /* grab pgd entry */ 157 beq tlb_miss_done_bolted /* tlb exists already, bail */ 158MMU_FTR_SECTION_ELSE 159 ldx r14,r14,r15 /* grab pgd entry */ 160ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV) 161 162 rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3 163 clrrdi r15,r15,3 164 cmpdi cr0,r14,0 165 bge tlb_miss_fault_bolted /* Bad pgd entry or hugepage; bail */ 166 ldx r14,r14,r15 /* grab pud entry */ 167 168 rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3 169 clrrdi r15,r15,3 170 cmpdi cr0,r14,0 171 bge tlb_miss_fault_bolted 172 ldx r14,r14,r15 /* Grab pmd entry */ 173 174 rldicl r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3 175 clrrdi r15,r15,3 176 cmpdi cr0,r14,0 177 bge tlb_miss_fault_bolted 178 ldx r14,r14,r15 /* Grab PTE, normal (!huge) page */ 179 180 /* Check if required permissions are met */ 181 andc. r15,r11,r14 182 rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT 183 bne- tlb_miss_fault_bolted 184 185 /* Now we build the MAS: 186 * 187 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG 188 * MAS 1 : Almost fully setup 189 * - PID already updated by caller if necessary 190 * - TSIZE need change if !base page size, not 191 * yet implemented for now 192 * MAS 2 : Defaults not useful, need to be redone 193 * MAS 3+7 : Needs to be done 194 */ 195 clrrdi r11,r16,12 /* Clear low crap in EA */ 196 clrldi r15,r15,12 /* Clear crap at the top */ 197 rlwimi r11,r14,32-19,27,31 /* Insert WIMGE */ 198 rlwimi r15,r14,32-8,22,25 /* Move in U bits */ 199 mtspr SPRN_MAS2,r11 200 andi. r11,r14,_PAGE_DIRTY 201 rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */ 202 203 /* Mask out SW and UW if !DIRTY (XXX optimize this !) */ 204 bne 1f 205 li r11,MAS3_SW|MAS3_UW 206 andc r15,r15,r11 2071: 208 mtspr SPRN_MAS7_MAS3,r15 209 tlbwe 210 211tlb_miss_done_bolted: 212 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK) 213 tlb_epilog_bolted 214 rfi 215 216itlb_miss_kernel_bolted: 217 li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */ 218 oris r11,r11,_PAGE_ACCESSED@h 219tlb_miss_kernel_bolted: 220 mfspr r10,SPRN_MAS1 221 ld r14,PACA_KERNELPGD(r13) 222 cmpldi cr0,r15,8 /* Check for vmalloc region */ 223 rlwinm r10,r10,0,16,1 /* Clear TID */ 224 mtspr SPRN_MAS1,r10 225 beq+ tlb_miss_common_bolted 226 227tlb_miss_fault_bolted: 228 /* We need to check if it was an instruction miss */ 229 andi. r10,r11,_PAGE_EXEC|_PAGE_BAP_SX 230 bne itlb_miss_fault_bolted 231dtlb_miss_fault_bolted: 232 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT) 233 tlb_epilog_bolted 234 b exc_data_storage_book3e 235itlb_miss_fault_bolted: 236 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT) 237 tlb_epilog_bolted 238 b exc_instruction_storage_book3e 239 240/* Instruction TLB miss */ 241 START_EXCEPTION(instruction_tlb_miss_bolted) 242 tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0 243 244 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4 245 srdi r15,r16,60 /* get region */ 246 TLB_MISS_STATS_SAVE_INFO_BOLTED 247 bne- itlb_miss_fault_bolted 248 249 li r11,_PAGE_PRESENT|_PAGE_EXEC /* Base perm */ 250 251 /* We do the user/kernel test for the PID here along with the RW test 252 */ 253 254 cmpldi cr0,r15,0 /* Check for user region */ 255 oris r11,r11,_PAGE_ACCESSED@h 256 beq tlb_miss_common_bolted 257 b itlb_miss_kernel_bolted 258 259#ifdef CONFIG_PPC_FSL_BOOK3E 260/* 261 * TLB miss handling for e6500 and derivatives, using hardware tablewalk. 262 * 263 * Linear mapping is bolted: no virtual page table or nested TLB misses 264 * Indirect entries in TLB1, hardware loads resulting direct entries 265 * into TLB0 266 * No HES or NV hint on TLB1, so we need to do software round-robin 267 * No tlbsrx. so we need a spinlock, and we have to deal 268 * with MAS-damage caused by tlbsx 269 * 4K pages only 270 */ 271 272 START_EXCEPTION(instruction_tlb_miss_e6500) 273 tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0 274 275 ld r11,PACA_TCD_PTR(r13) 276 srdi. r15,r16,60 /* get region */ 277 ori r16,r16,1 278 279 TLB_MISS_STATS_SAVE_INFO_BOLTED 280 bne tlb_miss_kernel_e6500 /* user/kernel test */ 281 282 b tlb_miss_common_e6500 283 284 START_EXCEPTION(data_tlb_miss_e6500) 285 tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR 286 287 ld r11,PACA_TCD_PTR(r13) 288 srdi. r15,r16,60 /* get region */ 289 rldicr r16,r16,0,62 290 291 TLB_MISS_STATS_SAVE_INFO_BOLTED 292 bne tlb_miss_kernel_e6500 /* user vs kernel check */ 293 294/* 295 * This is the guts of the TLB miss handler for e6500 and derivatives. 296 * We are entered with: 297 * 298 * r16 = page of faulting address (low bit 0 if data, 1 if instruction) 299 * r15 = crap (free to use) 300 * r14 = page table base 301 * r13 = PACA 302 * r11 = tlb_per_core ptr 303 * r10 = crap (free to use) 304 * r7 = esel_next 305 */ 306tlb_miss_common_e6500: 307 crmove cr2*4+2,cr0*4+2 /* cr2.eq != 0 if kernel address */ 308 309BEGIN_FTR_SECTION /* CPU_FTR_SMT */ 310 /* 311 * Search if we already have an indirect entry for that virtual 312 * address, and if we do, bail out. 313 * 314 * MAS6:IND should be already set based on MAS4 315 */ 316 lhz r10,PACAPACAINDEX(r13) 317 addi r10,r10,1 318 crclr cr1*4+eq /* set cr1.eq = 0 for non-recursive */ 3191: lbarx r15,0,r11 320 cmpdi r15,0 321 bne 2f 322 stbcx. r10,0,r11 323 bne 1b 3243: 325 .subsection 1 3262: cmpd cr1,r15,r10 /* recursive lock due to mcheck/crit/etc? */ 327 beq cr1,3b /* unlock will happen if cr1.eq = 0 */ 32810: lbz r15,0(r11) 329 cmpdi r15,0 330 bne 10b 331 b 1b 332 .previous 333END_FTR_SECTION_IFSET(CPU_FTR_SMT) 334 335 lbz r7,TCD_ESEL_NEXT(r11) 336 337BEGIN_FTR_SECTION /* CPU_FTR_SMT */ 338 /* 339 * Erratum A-008139 says that we can't use tlbwe to change 340 * an indirect entry in any way (including replacing or 341 * invalidating) if the other thread could be in the process 342 * of a lookup. The workaround is to invalidate the entry 343 * with tlbilx before overwriting. 344 */ 345 346 rlwinm r10,r7,16,0xff0000 347 oris r10,r10,MAS0_TLBSEL(1)@h 348 mtspr SPRN_MAS0,r10 349 isync 350 tlbre 351 mfspr r15,SPRN_MAS1 352 andis. r15,r15,MAS1_VALID@h 353 beq 5f 354 355BEGIN_FTR_SECTION_NESTED(532) 356 mfspr r10,SPRN_MAS8 357 rlwinm r10,r10,0,0x80000fff /* tgs,tlpid -> sgs,slpid */ 358 mtspr SPRN_MAS5,r10 359END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532) 360 361 mfspr r10,SPRN_MAS1 362 rlwinm r15,r10,0,0x3fff0000 /* tid -> spid */ 363 rlwimi r15,r10,20,0x00000003 /* ind,ts -> sind,sas */ 364 mfspr r10,SPRN_MAS6 365 mtspr SPRN_MAS6,r15 366 367 mfspr r15,SPRN_MAS2 368 isync 369 tlbilxva 0,r15 370 isync 371 372 mtspr SPRN_MAS6,r10 373 3745: 375BEGIN_FTR_SECTION_NESTED(532) 376 li r10,0 377 mtspr SPRN_MAS8,r10 378 mtspr SPRN_MAS5,r10 379END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532) 380 381 tlbsx 0,r16 382 mfspr r10,SPRN_MAS1 383 andis. r15,r10,MAS1_VALID@h 384 bne tlb_miss_done_e6500 385FTR_SECTION_ELSE 386 mfspr r10,SPRN_MAS1 387ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT) 388 389 oris r10,r10,MAS1_VALID@h 390 beq cr2,4f 391 rlwinm r10,r10,0,16,1 /* Clear TID */ 3924: mtspr SPRN_MAS1,r10 393 394 /* Now, we need to walk the page tables. First check if we are in 395 * range. 396 */ 397 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4 398 bne- tlb_miss_fault_e6500 399 400 rldicl r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3 401 cmpldi cr0,r14,0 402 clrrdi r15,r15,3 403 beq- tlb_miss_fault_e6500 /* No PGDIR, bail */ 404 ldx r14,r14,r15 /* grab pgd entry */ 405 406 rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3 407 clrrdi r15,r15,3 408 cmpdi cr0,r14,0 409 bge tlb_miss_huge_e6500 /* Bad pgd entry or hugepage; bail */ 410 ldx r14,r14,r15 /* grab pud entry */ 411 412 rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3 413 clrrdi r15,r15,3 414 cmpdi cr0,r14,0 415 bge tlb_miss_huge_e6500 416 ldx r14,r14,r15 /* Grab pmd entry */ 417 418 mfspr r10,SPRN_MAS0 419 cmpdi cr0,r14,0 420 bge tlb_miss_huge_e6500 421 422 /* Now we build the MAS for a 2M indirect page: 423 * 424 * MAS 0 : ESEL needs to be filled by software round-robin 425 * MAS 1 : Fully set up 426 * - PID already updated by caller if necessary 427 * - TSIZE for now is base ind page size always 428 * - TID already cleared if necessary 429 * MAS 2 : Default not 2M-aligned, need to be redone 430 * MAS 3+7 : Needs to be done 431 */ 432 433 ori r14,r14,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT) 434 mtspr SPRN_MAS7_MAS3,r14 435 436 clrrdi r15,r16,21 /* make EA 2M-aligned */ 437 mtspr SPRN_MAS2,r15 438 439tlb_miss_huge_done_e6500: 440 lbz r16,TCD_ESEL_MAX(r11) 441 lbz r14,TCD_ESEL_FIRST(r11) 442 rlwimi r10,r7,16,0x00ff0000 /* insert esel_next into MAS0 */ 443 addi r7,r7,1 /* increment esel_next */ 444 mtspr SPRN_MAS0,r10 445 cmpw r7,r16 446 iseleq r7,r14,r7 /* if next == last use first */ 447 stb r7,TCD_ESEL_NEXT(r11) 448 449 tlbwe 450 451tlb_miss_done_e6500: 452 .macro tlb_unlock_e6500 453BEGIN_FTR_SECTION 454 beq cr1,1f /* no unlock if lock was recursively grabbed */ 455 li r15,0 456 isync 457 stb r15,0(r11) 4581: 459END_FTR_SECTION_IFSET(CPU_FTR_SMT) 460 .endm 461 462 tlb_unlock_e6500 463 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK) 464 tlb_epilog_bolted 465 rfi 466 467tlb_miss_huge_e6500: 468 beq tlb_miss_fault_e6500 469 li r10,1 470 andi. r15,r14,HUGEPD_SHIFT_MASK@l /* r15 = psize */ 471 rldimi r14,r10,63,0 /* Set PD_HUGE */ 472 xor r14,r14,r15 /* Clear size bits */ 473 ldx r14,0,r14 474 475 /* 476 * Now we build the MAS for a huge page. 477 * 478 * MAS 0 : ESEL needs to be filled by software round-robin 479 * - can be handled by indirect code 480 * MAS 1 : Need to clear IND and set TSIZE 481 * MAS 2,3+7: Needs to be redone similar to non-tablewalk handler 482 */ 483 484 subi r15,r15,10 /* Convert psize to tsize */ 485 mfspr r10,SPRN_MAS1 486 rlwinm r10,r10,0,~MAS1_IND 487 rlwimi r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK 488 mtspr SPRN_MAS1,r10 489 490 li r10,-0x400 491 sld r15,r10,r15 /* Generate mask based on size */ 492 and r10,r16,r15 493 rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT 494 rlwimi r10,r14,32-19,27,31 /* Insert WIMGE */ 495 clrldi r15,r15,PAGE_SHIFT /* Clear crap at the top */ 496 rlwimi r15,r14,32-8,22,25 /* Move in U bits */ 497 mtspr SPRN_MAS2,r10 498 andi. r10,r14,_PAGE_DIRTY 499 rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */ 500 501 /* Mask out SW and UW if !DIRTY (XXX optimize this !) */ 502 bne 1f 503 li r10,MAS3_SW|MAS3_UW 504 andc r15,r15,r10 5051: 506 mtspr SPRN_MAS7_MAS3,r15 507 508 mfspr r10,SPRN_MAS0 509 b tlb_miss_huge_done_e6500 510 511tlb_miss_kernel_e6500: 512 ld r14,PACA_KERNELPGD(r13) 513 cmpldi cr1,r15,8 /* Check for vmalloc region */ 514 beq+ cr1,tlb_miss_common_e6500 515 516tlb_miss_fault_e6500: 517 tlb_unlock_e6500 518 /* We need to check if it was an instruction miss */ 519 andi. r16,r16,1 520 bne itlb_miss_fault_e6500 521dtlb_miss_fault_e6500: 522 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT) 523 tlb_epilog_bolted 524 b exc_data_storage_book3e 525itlb_miss_fault_e6500: 526 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT) 527 tlb_epilog_bolted 528 b exc_instruction_storage_book3e 529#endif /* CONFIG_PPC_FSL_BOOK3E */ 530 531/********************************************************************** 532 * * 533 * TLB miss handling for Book3E with TLB reservation and HES support * 534 * * 535 **********************************************************************/ 536 537 538/* Data TLB miss */ 539 START_EXCEPTION(data_tlb_miss) 540 TLB_MISS_PROLOG 541 542 /* Now we handle the fault proper. We only save DEAR in normal 543 * fault case since that's the only interesting values here. 544 * We could probably also optimize by not saving SRR0/1 in the 545 * linear mapping case but I'll leave that for later 546 */ 547 mfspr r14,SPRN_ESR 548 mfspr r16,SPRN_DEAR /* get faulting address */ 549 srdi r15,r16,60 /* get region */ 550 cmpldi cr0,r15,0xc /* linear mapping ? */ 551 TLB_MISS_STATS_SAVE_INFO 552 beq tlb_load_linear /* yes -> go to linear map load */ 553 554 /* The page tables are mapped virtually linear. At this point, though, 555 * we don't know whether we are trying to fault in a first level 556 * virtual address or a virtual page table address. We can get that 557 * from bit 0x1 of the region ID which we have set for a page table 558 */ 559 andi. r10,r15,0x1 560 bne- virt_page_table_tlb_miss 561 562 std r14,EX_TLB_ESR(r12); /* save ESR */ 563 std r16,EX_TLB_DEAR(r12); /* save DEAR */ 564 565 /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */ 566 li r11,_PAGE_PRESENT 567 oris r11,r11,_PAGE_ACCESSED@h 568 569 /* We do the user/kernel test for the PID here along with the RW test 570 */ 571 cmpldi cr0,r15,0 /* Check for user region */ 572 573 /* We pre-test some combination of permissions to avoid double 574 * faults: 575 * 576 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE 577 * ESR_ST is 0x00800000 578 * _PAGE_BAP_SW is 0x00000010 579 * So the shift is >> 19. This tests for supervisor writeability. 580 * If the page happens to be supervisor writeable and not user 581 * writeable, we will take a new fault later, but that should be 582 * a rare enough case. 583 * 584 * We also move ESR_ST in _PAGE_DIRTY position 585 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11 586 * 587 * MAS1 is preset for all we need except for TID that needs to 588 * be cleared for kernel translations 589 */ 590 rlwimi r11,r14,32-19,27,27 591 rlwimi r11,r14,32-16,19,19 592 beq normal_tlb_miss 593 /* XXX replace the RMW cycles with immediate loads + writes */ 5941: mfspr r10,SPRN_MAS1 595 cmpldi cr0,r15,8 /* Check for vmalloc region */ 596 rlwinm r10,r10,0,16,1 /* Clear TID */ 597 mtspr SPRN_MAS1,r10 598 beq+ normal_tlb_miss 599 600 /* We got a crappy address, just fault with whatever DEAR and ESR 601 * are here 602 */ 603 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT) 604 TLB_MISS_EPILOG_ERROR 605 b exc_data_storage_book3e 606 607/* Instruction TLB miss */ 608 START_EXCEPTION(instruction_tlb_miss) 609 TLB_MISS_PROLOG 610 611 /* If we take a recursive fault, the second level handler may need 612 * to know whether we are handling a data or instruction fault in 613 * order to get to the right store fault handler. We provide that 614 * info by writing a crazy value in ESR in our exception frame 615 */ 616 li r14,-1 /* store to exception frame is done later */ 617 618 /* Now we handle the fault proper. We only save DEAR in the non 619 * linear mapping case since we know the linear mapping case will 620 * not re-enter. We could indeed optimize and also not save SRR0/1 621 * in the linear mapping case but I'll leave that for later 622 * 623 * Faulting address is SRR0 which is already in r16 624 */ 625 srdi r15,r16,60 /* get region */ 626 cmpldi cr0,r15,0xc /* linear mapping ? */ 627 TLB_MISS_STATS_SAVE_INFO 628 beq tlb_load_linear /* yes -> go to linear map load */ 629 630 /* We do the user/kernel test for the PID here along with the RW test 631 */ 632 li r11,_PAGE_PRESENT|_PAGE_EXEC /* Base perm */ 633 oris r11,r11,_PAGE_ACCESSED@h 634 635 cmpldi cr0,r15,0 /* Check for user region */ 636 std r14,EX_TLB_ESR(r12) /* write crazy -1 to frame */ 637 beq normal_tlb_miss 638 639 li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */ 640 oris r11,r11,_PAGE_ACCESSED@h 641 /* XXX replace the RMW cycles with immediate loads + writes */ 642 mfspr r10,SPRN_MAS1 643 cmpldi cr0,r15,8 /* Check for vmalloc region */ 644 rlwinm r10,r10,0,16,1 /* Clear TID */ 645 mtspr SPRN_MAS1,r10 646 beq+ normal_tlb_miss 647 648 /* We got a crappy address, just fault */ 649 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT) 650 TLB_MISS_EPILOG_ERROR 651 b exc_instruction_storage_book3e 652 653/* 654 * This is the guts of the first-level TLB miss handler for direct 655 * misses. We are entered with: 656 * 657 * r16 = faulting address 658 * r15 = region ID 659 * r14 = crap (free to use) 660 * r13 = PACA 661 * r12 = TLB exception frame in PACA 662 * r11 = PTE permission mask 663 * r10 = crap (free to use) 664 */ 665normal_tlb_miss: 666 /* So we first construct the page table address. We do that by 667 * shifting the bottom of the address (not the region ID) by 668 * PAGE_SHIFT-3, clearing the bottom 3 bits (get a PTE ptr) and 669 * or'ing the fourth high bit. 670 * 671 * NOTE: For 64K pages, we do things slightly differently in 672 * order to handle the weird page table format used by linux 673 */ 674 ori r10,r15,0x1 675 rldicl r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4 676 sldi r15,r10,60 677 clrrdi r14,r14,3 678 or r10,r15,r14 679 680BEGIN_MMU_FTR_SECTION 681 /* Set the TLB reservation and search for existing entry. Then load 682 * the entry. 683 */ 684 PPC_TLBSRX_DOT(0,R16) 685 ld r14,0(r10) 686 beq normal_tlb_miss_done 687MMU_FTR_SECTION_ELSE 688 ld r14,0(r10) 689ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV) 690 691finish_normal_tlb_miss: 692 /* Check if required permissions are met */ 693 andc. r15,r11,r14 694 bne- normal_tlb_miss_access_fault 695 696 /* Now we build the MAS: 697 * 698 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG 699 * MAS 1 : Almost fully setup 700 * - PID already updated by caller if necessary 701 * - TSIZE need change if !base page size, not 702 * yet implemented for now 703 * MAS 2 : Defaults not useful, need to be redone 704 * MAS 3+7 : Needs to be done 705 * 706 * TODO: mix up code below for better scheduling 707 */ 708 clrrdi r11,r16,12 /* Clear low crap in EA */ 709 rlwimi r11,r14,32-19,27,31 /* Insert WIMGE */ 710 mtspr SPRN_MAS2,r11 711 712 /* Check page size, if not standard, update MAS1 */ 713 rldicl r11,r14,64-8,64-8 714 cmpldi cr0,r11,BOOK3E_PAGESZ_4K 715 beq- 1f 716 mfspr r11,SPRN_MAS1 717 rlwimi r11,r14,31,21,24 718 rlwinm r11,r11,0,21,19 719 mtspr SPRN_MAS1,r11 7201: 721 /* Move RPN in position */ 722 rldicr r11,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT 723 clrldi r15,r11,12 /* Clear crap at the top */ 724 rlwimi r15,r14,32-8,22,25 /* Move in U bits */ 725 rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */ 726 727 /* Mask out SW and UW if !DIRTY (XXX optimize this !) */ 728 andi. r11,r14,_PAGE_DIRTY 729 bne 1f 730 li r11,MAS3_SW|MAS3_UW 731 andc r15,r15,r11 7321: 733BEGIN_MMU_FTR_SECTION 734 srdi r16,r15,32 735 mtspr SPRN_MAS3,r15 736 mtspr SPRN_MAS7,r16 737MMU_FTR_SECTION_ELSE 738 mtspr SPRN_MAS7_MAS3,r15 739ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS) 740 741 tlbwe 742 743normal_tlb_miss_done: 744 /* We don't bother with restoring DEAR or ESR since we know we are 745 * level 0 and just going back to userland. They are only needed 746 * if you are going to take an access fault 747 */ 748 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK) 749 TLB_MISS_EPILOG_SUCCESS 750 rfi 751 752normal_tlb_miss_access_fault: 753 /* We need to check if it was an instruction miss */ 754 andi. r10,r11,_PAGE_EXEC 755 bne 1f 756 ld r14,EX_TLB_DEAR(r12) 757 ld r15,EX_TLB_ESR(r12) 758 mtspr SPRN_DEAR,r14 759 mtspr SPRN_ESR,r15 760 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT) 761 TLB_MISS_EPILOG_ERROR 762 b exc_data_storage_book3e 7631: TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT) 764 TLB_MISS_EPILOG_ERROR 765 b exc_instruction_storage_book3e 766 767 768/* 769 * This is the guts of the second-level TLB miss handler for direct 770 * misses. We are entered with: 771 * 772 * r16 = virtual page table faulting address 773 * r15 = region (top 4 bits of address) 774 * r14 = crap (free to use) 775 * r13 = PACA 776 * r12 = TLB exception frame in PACA 777 * r11 = crap (free to use) 778 * r10 = crap (free to use) 779 * 780 * Note that this should only ever be called as a second level handler 781 * with the current scheme when using SW load. 782 * That means we can always get the original fault DEAR at 783 * EX_TLB_DEAR-EX_TLB_SIZE(r12) 784 * 785 * It can be re-entered by the linear mapping miss handler. However, to 786 * avoid too much complication, it will restart the whole fault at level 787 * 0 so we don't care too much about clobbers 788 * 789 * XXX That code was written back when we couldn't clobber r14. We can now, 790 * so we could probably optimize things a bit 791 */ 792virt_page_table_tlb_miss: 793 /* Are we hitting a kernel page table ? */ 794 andi. r10,r15,0x8 795 796 /* The cool thing now is that r10 contains 0 for user and 8 for kernel, 797 * and we happen to have the swapper_pg_dir at offset 8 from the user 798 * pgdir in the PACA :-). 799 */ 800 add r11,r10,r13 801 802 /* If kernel, we need to clear MAS1 TID */ 803 beq 1f 804 /* XXX replace the RMW cycles with immediate loads + writes */ 805 mfspr r10,SPRN_MAS1 806 rlwinm r10,r10,0,16,1 /* Clear TID */ 807 mtspr SPRN_MAS1,r10 8081: 809BEGIN_MMU_FTR_SECTION 810 /* Search if we already have a TLB entry for that virtual address, and 811 * if we do, bail out. 812 */ 813 PPC_TLBSRX_DOT(0,R16) 814 beq virt_page_table_tlb_miss_done 815END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV) 816 817 /* Now, we need to walk the page tables. First check if we are in 818 * range. 819 */ 820 rldicl. r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4 821 bne- virt_page_table_tlb_miss_fault 822 823 /* Get the PGD pointer */ 824 ld r15,PACAPGD(r11) 825 cmpldi cr0,r15,0 826 beq- virt_page_table_tlb_miss_fault 827 828 /* Get to PGD entry */ 829 rldicl r11,r16,64-VPTE_PGD_SHIFT,64-PGD_INDEX_SIZE-3 830 clrrdi r10,r11,3 831 ldx r15,r10,r15 832 cmpdi cr0,r15,0 833 bge virt_page_table_tlb_miss_fault 834 835 /* Get to PUD entry */ 836 rldicl r11,r16,64-VPTE_PUD_SHIFT,64-PUD_INDEX_SIZE-3 837 clrrdi r10,r11,3 838 ldx r15,r10,r15 839 cmpdi cr0,r15,0 840 bge virt_page_table_tlb_miss_fault 841 842 /* Get to PMD entry */ 843 rldicl r11,r16,64-VPTE_PMD_SHIFT,64-PMD_INDEX_SIZE-3 844 clrrdi r10,r11,3 845 ldx r15,r10,r15 846 cmpdi cr0,r15,0 847 bge virt_page_table_tlb_miss_fault 848 849 /* Ok, we're all right, we can now create a kernel translation for 850 * a 4K or 64K page from r16 -> r15. 851 */ 852 /* Now we build the MAS: 853 * 854 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG 855 * MAS 1 : Almost fully setup 856 * - PID already updated by caller if necessary 857 * - TSIZE for now is base page size always 858 * MAS 2 : Use defaults 859 * MAS 3+7 : Needs to be done 860 * 861 * So we only do MAS 2 and 3 for now... 862 */ 863 clrldi r11,r15,4 /* remove region ID from RPN */ 864 ori r10,r11,1 /* Or-in SR */ 865 866BEGIN_MMU_FTR_SECTION 867 srdi r16,r10,32 868 mtspr SPRN_MAS3,r10 869 mtspr SPRN_MAS7,r16 870MMU_FTR_SECTION_ELSE 871 mtspr SPRN_MAS7_MAS3,r10 872ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS) 873 874 tlbwe 875 876BEGIN_MMU_FTR_SECTION 877virt_page_table_tlb_miss_done: 878 879 /* We have overridden MAS2:EPN but currently our primary TLB miss 880 * handler will always restore it so that should not be an issue, 881 * if we ever optimize the primary handler to not write MAS2 on 882 * some cases, we'll have to restore MAS2:EPN here based on the 883 * original fault's DEAR. If we do that we have to modify the 884 * ITLB miss handler to also store SRR0 in the exception frame 885 * as DEAR. 886 * 887 * However, one nasty thing we did is we cleared the reservation 888 * (well, potentially we did). We do a trick here thus if we 889 * are not a level 0 exception (we interrupted the TLB miss) we 890 * offset the return address by -4 in order to replay the tlbsrx 891 * instruction there 892 */ 893 subf r10,r13,r12 894 cmpldi cr0,r10,PACA_EXTLB+EX_TLB_SIZE 895 bne- 1f 896 ld r11,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13) 897 addi r10,r11,-4 898 std r10,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13) 8991: 900END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV) 901 /* Return to caller, normal case */ 902 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_OK); 903 TLB_MISS_EPILOG_SUCCESS 904 rfi 905 906virt_page_table_tlb_miss_fault: 907 /* If we fault here, things are a little bit tricky. We need to call 908 * either data or instruction store fault, and we need to retrieve 909 * the original fault address and ESR (for data). 910 * 911 * The thing is, we know that in normal circumstances, this is 912 * always called as a second level tlb miss for SW load or as a first 913 * level TLB miss for HW load, so we should be able to peek at the 914 * relevant information in the first exception frame in the PACA. 915 * 916 * However, we do need to double check that, because we may just hit 917 * a stray kernel pointer or a userland attack trying to hit those 918 * areas. If that is the case, we do a data fault. (We can't get here 919 * from an instruction tlb miss anyway). 920 * 921 * Note also that when going to a fault, we must unwind the previous 922 * level as well. Since we are doing that, we don't need to clear or 923 * restore the TLB reservation neither. 924 */ 925 subf r10,r13,r12 926 cmpldi cr0,r10,PACA_EXTLB+EX_TLB_SIZE 927 bne- virt_page_table_tlb_miss_whacko_fault 928 929 /* We dig the original DEAR and ESR from slot 0 */ 930 ld r15,EX_TLB_DEAR+PACA_EXTLB(r13) 931 ld r16,EX_TLB_ESR+PACA_EXTLB(r13) 932 933 /* We check for the "special" ESR value for instruction faults */ 934 cmpdi cr0,r16,-1 935 beq 1f 936 mtspr SPRN_DEAR,r15 937 mtspr SPRN_ESR,r16 938 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_PT_FAULT); 939 TLB_MISS_EPILOG_ERROR 940 b exc_data_storage_book3e 9411: TLB_MISS_STATS_I(MMSTAT_TLB_MISS_PT_FAULT); 942 TLB_MISS_EPILOG_ERROR 943 b exc_instruction_storage_book3e 944 945virt_page_table_tlb_miss_whacko_fault: 946 /* The linear fault will restart everything so ESR and DEAR will 947 * not have been clobbered, let's just fault with what we have 948 */ 949 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_FAULT); 950 TLB_MISS_EPILOG_ERROR 951 b exc_data_storage_book3e 952 953 954/************************************************************** 955 * * 956 * TLB miss handling for Book3E with hw page table support * 957 * * 958 **************************************************************/ 959 960 961/* Data TLB miss */ 962 START_EXCEPTION(data_tlb_miss_htw) 963 TLB_MISS_PROLOG 964 965 /* Now we handle the fault proper. We only save DEAR in normal 966 * fault case since that's the only interesting values here. 967 * We could probably also optimize by not saving SRR0/1 in the 968 * linear mapping case but I'll leave that for later 969 */ 970 mfspr r14,SPRN_ESR 971 mfspr r16,SPRN_DEAR /* get faulting address */ 972 srdi r11,r16,60 /* get region */ 973 cmpldi cr0,r11,0xc /* linear mapping ? */ 974 TLB_MISS_STATS_SAVE_INFO 975 beq tlb_load_linear /* yes -> go to linear map load */ 976 977 /* We do the user/kernel test for the PID here along with the RW test 978 */ 979 cmpldi cr0,r11,0 /* Check for user region */ 980 ld r15,PACAPGD(r13) /* Load user pgdir */ 981 beq htw_tlb_miss 982 983 /* XXX replace the RMW cycles with immediate loads + writes */ 9841: mfspr r10,SPRN_MAS1 985 cmpldi cr0,r11,8 /* Check for vmalloc region */ 986 rlwinm r10,r10,0,16,1 /* Clear TID */ 987 mtspr SPRN_MAS1,r10 988 ld r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */ 989 beq+ htw_tlb_miss 990 991 /* We got a crappy address, just fault with whatever DEAR and ESR 992 * are here 993 */ 994 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT) 995 TLB_MISS_EPILOG_ERROR 996 b exc_data_storage_book3e 997 998/* Instruction TLB miss */ 999 START_EXCEPTION(instruction_tlb_miss_htw) 1000 TLB_MISS_PROLOG 1001 1002 /* If we take a recursive fault, the second level handler may need 1003 * to know whether we are handling a data or instruction fault in 1004 * order to get to the right store fault handler. We provide that 1005 * info by keeping a crazy value for ESR in r14 1006 */ 1007 li r14,-1 /* store to exception frame is done later */ 1008 1009 /* Now we handle the fault proper. We only save DEAR in the non 1010 * linear mapping case since we know the linear mapping case will 1011 * not re-enter. We could indeed optimize and also not save SRR0/1 1012 * in the linear mapping case but I'll leave that for later 1013 * 1014 * Faulting address is SRR0 which is already in r16 1015 */ 1016 srdi r11,r16,60 /* get region */ 1017 cmpldi cr0,r11,0xc /* linear mapping ? */ 1018 TLB_MISS_STATS_SAVE_INFO 1019 beq tlb_load_linear /* yes -> go to linear map load */ 1020 1021 /* We do the user/kernel test for the PID here along with the RW test 1022 */ 1023 cmpldi cr0,r11,0 /* Check for user region */ 1024 ld r15,PACAPGD(r13) /* Load user pgdir */ 1025 beq htw_tlb_miss 1026 1027 /* XXX replace the RMW cycles with immediate loads + writes */ 10281: mfspr r10,SPRN_MAS1 1029 cmpldi cr0,r11,8 /* Check for vmalloc region */ 1030 rlwinm r10,r10,0,16,1 /* Clear TID */ 1031 mtspr SPRN_MAS1,r10 1032 ld r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */ 1033 beq+ htw_tlb_miss 1034 1035 /* We got a crappy address, just fault */ 1036 TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT) 1037 TLB_MISS_EPILOG_ERROR 1038 b exc_instruction_storage_book3e 1039 1040 1041/* 1042 * This is the guts of the second-level TLB miss handler for direct 1043 * misses. We are entered with: 1044 * 1045 * r16 = virtual page table faulting address 1046 * r15 = PGD pointer 1047 * r14 = ESR 1048 * r13 = PACA 1049 * r12 = TLB exception frame in PACA 1050 * r11 = crap (free to use) 1051 * r10 = crap (free to use) 1052 * 1053 * It can be re-entered by the linear mapping miss handler. However, to 1054 * avoid too much complication, it will save/restore things for us 1055 */ 1056htw_tlb_miss: 1057 /* Search if we already have a TLB entry for that virtual address, and 1058 * if we do, bail out. 1059 * 1060 * MAS1:IND should be already set based on MAS4 1061 */ 1062 PPC_TLBSRX_DOT(0,R16) 1063 beq htw_tlb_miss_done 1064 1065 /* Now, we need to walk the page tables. First check if we are in 1066 * range. 1067 */ 1068 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4 1069 bne- htw_tlb_miss_fault 1070 1071 /* Get the PGD pointer */ 1072 cmpldi cr0,r15,0 1073 beq- htw_tlb_miss_fault 1074 1075 /* Get to PGD entry */ 1076 rldicl r11,r16,64-(PGDIR_SHIFT-3),64-PGD_INDEX_SIZE-3 1077 clrrdi r10,r11,3 1078 ldx r15,r10,r15 1079 cmpdi cr0,r15,0 1080 bge htw_tlb_miss_fault 1081 1082 /* Get to PUD entry */ 1083 rldicl r11,r16,64-(PUD_SHIFT-3),64-PUD_INDEX_SIZE-3 1084 clrrdi r10,r11,3 1085 ldx r15,r10,r15 1086 cmpdi cr0,r15,0 1087 bge htw_tlb_miss_fault 1088 1089 /* Get to PMD entry */ 1090 rldicl r11,r16,64-(PMD_SHIFT-3),64-PMD_INDEX_SIZE-3 1091 clrrdi r10,r11,3 1092 ldx r15,r10,r15 1093 cmpdi cr0,r15,0 1094 bge htw_tlb_miss_fault 1095 1096 /* Ok, we're all right, we can now create an indirect entry for 1097 * a 1M or 256M page. 1098 * 1099 * The last trick is now that because we use "half" pages for 1100 * the HTW (1M IND is 2K and 256M IND is 32K) we need to account 1101 * for an added LSB bit to the RPN. For 64K pages, there is no 1102 * problem as we already use 32K arrays (half PTE pages), but for 1103 * 4K page we need to extract a bit from the virtual address and 1104 * insert it into the "PA52" bit of the RPN. 1105 */ 1106 rlwimi r15,r16,32-9,20,20 1107 /* Now we build the MAS: 1108 * 1109 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG 1110 * MAS 1 : Almost fully setup 1111 * - PID already updated by caller if necessary 1112 * - TSIZE for now is base ind page size always 1113 * MAS 2 : Use defaults 1114 * MAS 3+7 : Needs to be done 1115 */ 1116 ori r10,r15,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT) 1117 1118BEGIN_MMU_FTR_SECTION 1119 srdi r16,r10,32 1120 mtspr SPRN_MAS3,r10 1121 mtspr SPRN_MAS7,r16 1122MMU_FTR_SECTION_ELSE 1123 mtspr SPRN_MAS7_MAS3,r10 1124ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS) 1125 1126 tlbwe 1127 1128htw_tlb_miss_done: 1129 /* We don't bother with restoring DEAR or ESR since we know we are 1130 * level 0 and just going back to userland. They are only needed 1131 * if you are going to take an access fault 1132 */ 1133 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_OK) 1134 TLB_MISS_EPILOG_SUCCESS 1135 rfi 1136 1137htw_tlb_miss_fault: 1138 /* We need to check if it was an instruction miss. We know this 1139 * though because r14 would contain -1 1140 */ 1141 cmpdi cr0,r14,-1 1142 beq 1f 1143 mtspr SPRN_DEAR,r16 1144 mtspr SPRN_ESR,r14 1145 TLB_MISS_STATS_D(MMSTAT_TLB_MISS_PT_FAULT) 1146 TLB_MISS_EPILOG_ERROR 1147 b exc_data_storage_book3e 11481: TLB_MISS_STATS_I(MMSTAT_TLB_MISS_PT_FAULT) 1149 TLB_MISS_EPILOG_ERROR 1150 b exc_instruction_storage_book3e 1151 1152/* 1153 * This is the guts of "any" level TLB miss handler for kernel linear 1154 * mapping misses. We are entered with: 1155 * 1156 * 1157 * r16 = faulting address 1158 * r15 = crap (free to use) 1159 * r14 = ESR (data) or -1 (instruction) 1160 * r13 = PACA 1161 * r12 = TLB exception frame in PACA 1162 * r11 = crap (free to use) 1163 * r10 = crap (free to use) 1164 * 1165 * In addition we know that we will not re-enter, so in theory, we could 1166 * use a simpler epilog not restoring SRR0/1 etc.. but we'll do that later. 1167 * 1168 * We also need to be careful about MAS registers here & TLB reservation, 1169 * as we know we'll have clobbered them if we interrupt the main TLB miss 1170 * handlers in which case we probably want to do a full restart at level 1171 * 0 rather than saving / restoring the MAS. 1172 * 1173 * Note: If we care about performance of that core, we can easily shuffle 1174 * a few things around 1175 */ 1176tlb_load_linear: 1177 /* For now, we assume the linear mapping is contiguous and stops at 1178 * linear_map_top. We also assume the size is a multiple of 1G, thus 1179 * we only use 1G pages for now. That might have to be changed in a 1180 * final implementation, especially when dealing with hypervisors 1181 */ 1182 ld r11,PACATOC(r13) 1183 ld r11,linear_map_top@got(r11) 1184 ld r10,0(r11) 1185 tovirt(10,10) 1186 cmpld cr0,r16,r10 1187 bge tlb_load_linear_fault 1188 1189 /* MAS1 need whole new setup. */ 1190 li r15,(BOOK3E_PAGESZ_1GB<<MAS1_TSIZE_SHIFT) 1191 oris r15,r15,MAS1_VALID@h /* MAS1 needs V and TSIZE */ 1192 mtspr SPRN_MAS1,r15 1193 1194 /* Already somebody there ? */ 1195 PPC_TLBSRX_DOT(0,R16) 1196 beq tlb_load_linear_done 1197 1198 /* Now we build the remaining MAS. MAS0 and 2 should be fine 1199 * with their defaults, which leaves us with MAS 3 and 7. The 1200 * mapping is linear, so we just take the address, clear the 1201 * region bits, and or in the permission bits which are currently 1202 * hard wired 1203 */ 1204 clrrdi r10,r16,30 /* 1G page index */ 1205 clrldi r10,r10,4 /* clear region bits */ 1206 ori r10,r10,MAS3_SR|MAS3_SW|MAS3_SX 1207 1208BEGIN_MMU_FTR_SECTION 1209 srdi r16,r10,32 1210 mtspr SPRN_MAS3,r10 1211 mtspr SPRN_MAS7,r16 1212MMU_FTR_SECTION_ELSE 1213 mtspr SPRN_MAS7_MAS3,r10 1214ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS) 1215 1216 tlbwe 1217 1218tlb_load_linear_done: 1219 /* We use the "error" epilog for success as we do want to 1220 * restore to the initial faulting context, whatever it was. 1221 * We do that because we can't resume a fault within a TLB 1222 * miss handler, due to MAS and TLB reservation being clobbered. 1223 */ 1224 TLB_MISS_STATS_X(MMSTAT_TLB_MISS_LINEAR) 1225 TLB_MISS_EPILOG_ERROR 1226 rfi 1227 1228tlb_load_linear_fault: 1229 /* We keep the DEAR and ESR around, this shouldn't have happened */ 1230 cmpdi cr0,r14,-1 1231 beq 1f 1232 TLB_MISS_EPILOG_ERROR_SPECIAL 1233 b exc_data_storage_book3e 12341: TLB_MISS_EPILOG_ERROR_SPECIAL 1235 b exc_instruction_storage_book3e 1236 1237 1238#ifdef CONFIG_BOOK3E_MMU_TLB_STATS 1239.tlb_stat_inc: 12401: ldarx r8,0,r9 1241 addi r8,r8,1 1242 stdcx. r8,0,r9 1243 bne- 1b 1244 blr 1245#endif 1246