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) 64START_BTB_FLUSH_SECTION 65 mfspr r11, SPRN_SRR1 66 andi. r10,r11,MSR_PR 67 beq 1f 68 BTB_FLUSH(r10) 691: 70END_BTB_FLUSH_SECTION 71 std r7,EX_TLB_R7(r12) 72.endm 73 74.macro tlb_epilog_bolted 75 ld r14,EX_TLB_CR(r12) 76 ld r7,EX_TLB_R7(r12) 77 ld r10,EX_TLB_R10(r12) 78 ld r11,EX_TLB_R11(r12) 79 ld r13,EX_TLB_R13(r12) 80 mtcr r14 81 ld r14,EX_TLB_R14(r12) 82 ld r15,EX_TLB_R15(r12) 83 ld r16,EX_TLB_R16(r12) 84 mfspr r12,SPRN_SPRG_GEN_SCRATCH 85.endm 86 87/* Data TLB miss */ 88 START_EXCEPTION(data_tlb_miss_bolted) 89 tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR 90 91 /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */ 92 93 /* We do the user/kernel test for the PID here along with the RW test 94 */ 95 /* We pre-test some combination of permissions to avoid double 96 * faults: 97 * 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. 105 * 106 * We also move ESR_ST in _PAGE_DIRTY position 107 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11 108 * 109 * MAS1 is preset for all we need except for TID that needs to 110 * be cleared for kernel translations 111 */ 112 113 mfspr r11,SPRN_ESR 114 115 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 */ 118 119 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 124 125 bne tlb_miss_kernel_bolted 126 127tlb_miss_user_bolted: 128#ifdef CONFIG_PPC_KUAP 129 mfspr r10,SPRN_MAS1 130 rlwinm. r10,r10,0,0x3fff0000 131 beq- tlb_miss_fault_bolted /* KUAP fault */ 132#endif 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 */ 150 151 ldx r14,r14,r15 /* grab pgd entry */ 152 153 rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3 154 clrrdi r15,r15,3 155 cmpdi cr0,r14,0 156 bge tlb_miss_fault_bolted /* Bad pgd entry or hugepage; bail */ 157 ldx r14,r14,r15 /* grab pud entry */ 158 159 rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3 160 clrrdi r15,r15,3 161 cmpdi cr0,r14,0 162 bge tlb_miss_fault_bolted 163 ldx r14,r14,r15 /* Grab pmd entry */ 164 165 rldicl r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3 166 clrrdi r15,r15,3 167 cmpdi cr0,r14,0 168 bge tlb_miss_fault_bolted 169 ldx r14,r14,r15 /* Grab PTE, normal (!huge) page */ 170 171 /* Check if required permissions are met */ 172 andc. r15,r11,r14 173 rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT 174 bne- tlb_miss_fault_bolted 175 176 /* Now we build the MAS: 177 * 178 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG 179 * MAS 1 : Almost fully setup 180 * - PID already updated by caller if necessary 181 * - TSIZE need change if !base page size, not 182 * yet implemented for now 183 * MAS 2 : Defaults not useful, need to be redone 184 * MAS 3+7 : Needs to be done 185 */ 186 clrrdi r11,r16,12 /* Clear low crap in EA */ 187 clrldi r15,r15,12 /* Clear crap at the top */ 188 rlwimi r11,r14,32-19,27,31 /* Insert WIMGE */ 189 rlwimi r15,r14,32-8,22,25 /* Move in U bits */ 190 mtspr SPRN_MAS2,r11 191 andi. r11,r14,_PAGE_DIRTY 192 rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */ 193 194 /* Mask out SW and UW if !DIRTY (XXX optimize this !) */ 195 bne 1f 196 li r11,MAS3_SW|MAS3_UW 197 andc r15,r15,r11 1981: 199 mtspr SPRN_MAS7_MAS3,r15 200 tlbwe 201 202tlb_miss_done_bolted: 203 tlb_epilog_bolted 204 rfi 205 206itlb_miss_kernel_bolted: 207 li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */ 208 oris r11,r11,_PAGE_ACCESSED@h 209tlb_miss_kernel_bolted: 210 mfspr r10,SPRN_MAS1 211 ld r14,PACA_KERNELPGD(r13) 212 srdi r15,r16,44 /* get kernel region */ 213 andi. r15,r15,1 /* Check for vmalloc region */ 214 rlwinm r10,r10,0,16,1 /* Clear TID */ 215 mtspr SPRN_MAS1,r10 216 bne+ tlb_miss_common_bolted 217 218tlb_miss_fault_bolted: 219 /* We need to check if it was an instruction miss */ 220 andi. r10,r11,_PAGE_BAP_UX|_PAGE_BAP_SX 221 bne itlb_miss_fault_bolted 222dtlb_miss_fault_bolted: 223 tlb_epilog_bolted 224 b exc_data_storage_book3e 225itlb_miss_fault_bolted: 226 tlb_epilog_bolted 227 b exc_instruction_storage_book3e 228 229/* Instruction TLB miss */ 230 START_EXCEPTION(instruction_tlb_miss_bolted) 231 tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0 232 233 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4 234 srdi r15,r16,60 /* get region */ 235 bne- itlb_miss_fault_bolted 236 237 li r11,_PAGE_PRESENT|_PAGE_BAP_UX /* Base perm */ 238 239 /* We do the user/kernel test for the PID here along with the RW test 240 */ 241 242 cmpldi cr0,r15,0 /* Check for user region */ 243 oris r11,r11,_PAGE_ACCESSED@h 244 beq tlb_miss_user_bolted 245 b itlb_miss_kernel_bolted 246 247/* 248 * TLB miss handling for e6500 and derivatives, using hardware tablewalk. 249 * 250 * Linear mapping is bolted: no virtual page table or nested TLB misses 251 * Indirect entries in TLB1, hardware loads resulting direct entries 252 * into TLB0 253 * No HES or NV hint on TLB1, so we need to do software round-robin 254 * No tlbsrx. so we need a spinlock, and we have to deal 255 * with MAS-damage caused by tlbsx 256 * 4K pages only 257 */ 258 259 START_EXCEPTION(instruction_tlb_miss_e6500) 260 tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0 261 262 ld r11,PACA_TCD_PTR(r13) 263 srdi. r15,r16,60 /* get region */ 264 ori r16,r16,1 265 266 bne tlb_miss_kernel_e6500 /* user/kernel test */ 267 268 b tlb_miss_common_e6500 269 270 START_EXCEPTION(data_tlb_miss_e6500) 271 tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR 272 273 ld r11,PACA_TCD_PTR(r13) 274 srdi. r15,r16,60 /* get region */ 275 rldicr r16,r16,0,62 276 277 bne tlb_miss_kernel_e6500 /* user vs kernel check */ 278 279/* 280 * This is the guts of the TLB miss handler for e6500 and derivatives. 281 * We are entered with: 282 * 283 * r16 = page of faulting address (low bit 0 if data, 1 if instruction) 284 * r15 = crap (free to use) 285 * r14 = page table base 286 * r13 = PACA 287 * r11 = tlb_per_core ptr 288 * r10 = crap (free to use) 289 * r7 = esel_next 290 */ 291tlb_miss_common_e6500: 292 crmove cr2*4+2,cr0*4+2 /* cr2.eq != 0 if kernel address */ 293 294BEGIN_FTR_SECTION /* CPU_FTR_SMT */ 295 /* 296 * Search if we already have an indirect entry for that virtual 297 * address, and if we do, bail out. 298 * 299 * MAS6:IND should be already set based on MAS4 300 */ 301 lhz r10,PACAPACAINDEX(r13) 302 addi r10,r10,1 303 crclr cr1*4+eq /* set cr1.eq = 0 for non-recursive */ 3041: lbarx r15,0,r11 305 cmpdi r15,0 306 bne 2f 307 stbcx. r10,0,r11 308 bne 1b 3093: 310 .subsection 1 3112: cmpd cr1,r15,r10 /* recursive lock due to mcheck/crit/etc? */ 312 beq cr1,3b /* unlock will happen if cr1.eq = 0 */ 31310: lbz r15,0(r11) 314 cmpdi r15,0 315 bne 10b 316 b 1b 317 .previous 318END_FTR_SECTION_IFSET(CPU_FTR_SMT) 319 320 lbz r7,TCD_ESEL_NEXT(r11) 321 322BEGIN_FTR_SECTION /* CPU_FTR_SMT */ 323 /* 324 * Erratum A-008139 says that we can't use tlbwe to change 325 * an indirect entry in any way (including replacing or 326 * invalidating) if the other thread could be in the process 327 * of a lookup. The workaround is to invalidate the entry 328 * with tlbilx before overwriting. 329 */ 330 331 rlwinm r10,r7,16,0xff0000 332 oris r10,r10,MAS0_TLBSEL(1)@h 333 mtspr SPRN_MAS0,r10 334 isync 335 tlbre 336 mfspr r15,SPRN_MAS1 337 andis. r15,r15,MAS1_VALID@h 338 beq 5f 339 340BEGIN_FTR_SECTION_NESTED(532) 341 mfspr r10,SPRN_MAS8 342 rlwinm r10,r10,0,0x80000fff /* tgs,tlpid -> sgs,slpid */ 343 mtspr SPRN_MAS5,r10 344END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532) 345 346 mfspr r10,SPRN_MAS1 347 rlwinm r15,r10,0,0x3fff0000 /* tid -> spid */ 348 rlwimi r15,r10,20,0x00000003 /* ind,ts -> sind,sas */ 349 mfspr r10,SPRN_MAS6 350 mtspr SPRN_MAS6,r15 351 352 mfspr r15,SPRN_MAS2 353 isync 354 PPC_TLBILX_VA(0,R15) 355 isync 356 357 mtspr SPRN_MAS6,r10 358 3595: 360BEGIN_FTR_SECTION_NESTED(532) 361 li r10,0 362 mtspr SPRN_MAS8,r10 363 mtspr SPRN_MAS5,r10 364END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532) 365 366 tlbsx 0,r16 367 mfspr r10,SPRN_MAS1 368 andis. r15,r10,MAS1_VALID@h 369 bne tlb_miss_done_e6500 370FTR_SECTION_ELSE 371 mfspr r10,SPRN_MAS1 372ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT) 373 374 oris r10,r10,MAS1_VALID@h 375 beq cr2,4f 376 rlwinm r10,r10,0,16,1 /* Clear TID */ 3774: mtspr SPRN_MAS1,r10 378 379 /* Now, we need to walk the page tables. First check if we are in 380 * range. 381 */ 382 rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4 383 bne- tlb_miss_fault_e6500 384 385 rldicl r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3 386 cmpldi cr0,r14,0 387 clrrdi r15,r15,3 388 beq- tlb_miss_fault_e6500 /* No PGDIR, bail */ 389 ldx r14,r14,r15 /* grab pgd entry */ 390 391 rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3 392 clrrdi r15,r15,3 393 cmpdi cr0,r14,0 394 bge tlb_miss_huge_e6500 /* Bad pgd entry or hugepage; bail */ 395 ldx r14,r14,r15 /* grab pud entry */ 396 397 rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3 398 clrrdi r15,r15,3 399 cmpdi cr0,r14,0 400 bge tlb_miss_huge_e6500 401 ldx r14,r14,r15 /* Grab pmd entry */ 402 403 mfspr r10,SPRN_MAS0 404 cmpdi cr0,r14,0 405 bge tlb_miss_huge_e6500 406 407 /* Now we build the MAS for a 2M indirect page: 408 * 409 * MAS 0 : ESEL needs to be filled by software round-robin 410 * MAS 1 : Fully set up 411 * - PID already updated by caller if necessary 412 * - TSIZE for now is base ind page size always 413 * - TID already cleared if necessary 414 * MAS 2 : Default not 2M-aligned, need to be redone 415 * MAS 3+7 : Needs to be done 416 */ 417 418 ori r14,r14,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT) 419 mtspr SPRN_MAS7_MAS3,r14 420 421 clrrdi r15,r16,21 /* make EA 2M-aligned */ 422 mtspr SPRN_MAS2,r15 423 424tlb_miss_huge_done_e6500: 425 lbz r16,TCD_ESEL_MAX(r11) 426 lbz r14,TCD_ESEL_FIRST(r11) 427 rlwimi r10,r7,16,0x00ff0000 /* insert esel_next into MAS0 */ 428 addi r7,r7,1 /* increment esel_next */ 429 mtspr SPRN_MAS0,r10 430 cmpw r7,r16 431 iseleq r7,r14,r7 /* if next == last use first */ 432 stb r7,TCD_ESEL_NEXT(r11) 433 434 tlbwe 435 436tlb_miss_done_e6500: 437 .macro tlb_unlock_e6500 438BEGIN_FTR_SECTION 439 beq cr1,1f /* no unlock if lock was recursively grabbed */ 440 li r15,0 441 isync 442 stb r15,0(r11) 4431: 444END_FTR_SECTION_IFSET(CPU_FTR_SMT) 445 .endm 446 447 tlb_unlock_e6500 448 tlb_epilog_bolted 449 rfi 450 451tlb_miss_huge_e6500: 452 beq tlb_miss_fault_e6500 453 li r10,1 454 andi. r15,r14,HUGEPD_SHIFT_MASK@l /* r15 = psize */ 455 rldimi r14,r10,63,0 /* Set PD_HUGE */ 456 xor r14,r14,r15 /* Clear size bits */ 457 ldx r14,0,r14 458 459 /* 460 * Now we build the MAS for a huge page. 461 * 462 * MAS 0 : ESEL needs to be filled by software round-robin 463 * - can be handled by indirect code 464 * MAS 1 : Need to clear IND and set TSIZE 465 * MAS 2,3+7: Needs to be redone similar to non-tablewalk handler 466 */ 467 468 subi r15,r15,10 /* Convert psize to tsize */ 469 mfspr r10,SPRN_MAS1 470 rlwinm r10,r10,0,~MAS1_IND 471 rlwimi r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK 472 mtspr SPRN_MAS1,r10 473 474 li r10,-0x400 475 sld r15,r10,r15 /* Generate mask based on size */ 476 and r10,r16,r15 477 rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT 478 rlwimi r10,r14,32-19,27,31 /* Insert WIMGE */ 479 clrldi r15,r15,PAGE_SHIFT /* Clear crap at the top */ 480 rlwimi r15,r14,32-8,22,25 /* Move in U bits */ 481 mtspr SPRN_MAS2,r10 482 andi. r10,r14,_PAGE_DIRTY 483 rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */ 484 485 /* Mask out SW and UW if !DIRTY (XXX optimize this !) */ 486 bne 1f 487 li r10,MAS3_SW|MAS3_UW 488 andc r15,r15,r10 4891: 490 mtspr SPRN_MAS7_MAS3,r15 491 492 mfspr r10,SPRN_MAS0 493 b tlb_miss_huge_done_e6500 494 495tlb_miss_kernel_e6500: 496 ld r14,PACA_KERNELPGD(r13) 497 srdi r15,r16,44 /* get kernel region */ 498 xoris r15,r15,0xc /* Check for vmalloc region */ 499 cmplwi cr1,r15,1 500 beq+ cr1,tlb_miss_common_e6500 501 502tlb_miss_fault_e6500: 503 tlb_unlock_e6500 504 /* We need to check if it was an instruction miss */ 505 andi. r16,r16,1 506 bne itlb_miss_fault_e6500 507dtlb_miss_fault_e6500: 508 tlb_epilog_bolted 509 b exc_data_storage_book3e 510itlb_miss_fault_e6500: 511 tlb_epilog_bolted 512 b exc_instruction_storage_book3e 513 514/* 515 * This is the guts of the second-level TLB miss handler for direct 516 * misses. We are entered with: 517 * 518 * r16 = virtual page table faulting address 519 * r15 = region (top 4 bits of address) 520 * r14 = crap (free to use) 521 * r13 = PACA 522 * r12 = TLB exception frame in PACA 523 * r11 = crap (free to use) 524 * r10 = crap (free to use) 525 * 526 * Note that this should only ever be called as a second level handler 527 * with the current scheme when using SW load. 528 * That means we can always get the original fault DEAR at 529 * EX_TLB_DEAR-EX_TLB_SIZE(r12) 530 * 531 * It can be re-entered by the linear mapping miss handler. However, to 532 * avoid too much complication, it will restart the whole fault at level 533 * 0 so we don't care too much about clobbers 534 * 535 * XXX That code was written back when we couldn't clobber r14. We can now, 536 * so we could probably optimize things a bit 537 */ 538virt_page_table_tlb_miss: 539 /* Are we hitting a kernel page table ? */ 540 srdi r15,r16,60 541 andi. r10,r15,0x8 542 543 /* The cool thing now is that r10 contains 0 for user and 8 for kernel, 544 * and we happen to have the swapper_pg_dir at offset 8 from the user 545 * pgdir in the PACA :-). 546 */ 547 add r11,r10,r13 548 549 /* If kernel, we need to clear MAS1 TID */ 550 beq 1f 551 /* XXX replace the RMW cycles with immediate loads + writes */ 552 mfspr r10,SPRN_MAS1 553 rlwinm r10,r10,0,16,1 /* Clear TID */ 554 mtspr SPRN_MAS1,r10 555#ifdef CONFIG_PPC_KUAP 556 b 2f 5571: 558 mfspr r10,SPRN_MAS1 559 rlwinm. r10,r10,0,0x3fff0000 560 beq- virt_page_table_tlb_miss_fault /* KUAP fault */ 5612: 562#else 5631: 564#endif 565 566 /* Now, we need to walk the page tables. First check if we are in 567 * range. 568 */ 569 rldicl r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4 570 cmpldi r10,0x80 571 bne- virt_page_table_tlb_miss_fault 572 573 /* Get the PGD pointer */ 574 ld r15,PACAPGD(r11) 575 cmpldi cr0,r15,0 576 beq- virt_page_table_tlb_miss_fault 577 578 /* Get to PGD entry */ 579 rldicl r11,r16,64-VPTE_PGD_SHIFT,64-PGD_INDEX_SIZE-3 580 clrrdi r10,r11,3 581 ldx r15,r10,r15 582 cmpdi cr0,r15,0 583 bge virt_page_table_tlb_miss_fault 584 585 /* Get to PUD entry */ 586 rldicl r11,r16,64-VPTE_PUD_SHIFT,64-PUD_INDEX_SIZE-3 587 clrrdi r10,r11,3 588 ldx r15,r10,r15 589 cmpdi cr0,r15,0 590 bge virt_page_table_tlb_miss_fault 591 592 /* Get to PMD entry */ 593 rldicl r11,r16,64-VPTE_PMD_SHIFT,64-PMD_INDEX_SIZE-3 594 clrrdi r10,r11,3 595 ldx r15,r10,r15 596 cmpdi cr0,r15,0 597 bge virt_page_table_tlb_miss_fault 598 599 /* Ok, we're all right, we can now create a kernel translation for 600 * a 4K or 64K page from r16 -> r15. 601 */ 602 /* Now we build the MAS: 603 * 604 * MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG 605 * MAS 1 : Almost fully setup 606 * - PID already updated by caller if necessary 607 * - TSIZE for now is base page size always 608 * MAS 2 : Use defaults 609 * MAS 3+7 : Needs to be done 610 * 611 * So we only do MAS 2 and 3 for now... 612 */ 613 clrldi r11,r15,4 /* remove region ID from RPN */ 614 ori r10,r11,1 /* Or-in SR */ 615 616 srdi r16,r10,32 617 mtspr SPRN_MAS3,r10 618 mtspr SPRN_MAS7,r16 619 620 tlbwe 621 622 /* Return to caller, normal case */ 623 TLB_MISS_EPILOG_SUCCESS 624 rfi 625 626virt_page_table_tlb_miss_fault: 627 /* If we fault here, things are a little bit tricky. We need to call 628 * either data or instruction store fault, and we need to retrieve 629 * the original fault address and ESR (for data). 630 * 631 * The thing is, we know that in normal circumstances, this is 632 * always called as a second level tlb miss for SW load or as a first 633 * level TLB miss for HW load, so we should be able to peek at the 634 * relevant information in the first exception frame in the PACA. 635 * 636 * However, we do need to double check that, because we may just hit 637 * a stray kernel pointer or a userland attack trying to hit those 638 * areas. If that is the case, we do a data fault. (We can't get here 639 * from an instruction tlb miss anyway). 640 * 641 * Note also that when going to a fault, we must unwind the previous 642 * level as well. Since we are doing that, we don't need to clear or 643 * restore the TLB reservation neither. 644 */ 645 subf r10,r13,r12 646 cmpldi cr0,r10,PACA_EXTLB+EX_TLB_SIZE 647 bne- virt_page_table_tlb_miss_whacko_fault 648 649 /* We dig the original DEAR and ESR from slot 0 */ 650 ld r15,EX_TLB_DEAR+PACA_EXTLB(r13) 651 ld r16,EX_TLB_ESR+PACA_EXTLB(r13) 652 653 /* We check for the "special" ESR value for instruction faults */ 654 cmpdi cr0,r16,-1 655 beq 1f 656 mtspr SPRN_DEAR,r15 657 mtspr SPRN_ESR,r16 658 TLB_MISS_EPILOG_ERROR 659 b exc_data_storage_book3e 6601: TLB_MISS_EPILOG_ERROR 661 b exc_instruction_storage_book3e 662 663virt_page_table_tlb_miss_whacko_fault: 664 /* The linear fault will restart everything so ESR and DEAR will 665 * not have been clobbered, let's just fault with what we have 666 */ 667 TLB_MISS_EPILOG_ERROR 668 b exc_data_storage_book3e 669 670/* 671 * This is the guts of "any" level TLB miss handler for kernel linear 672 * mapping misses. We are entered with: 673 * 674 * 675 * r16 = faulting address 676 * r15 = crap (free to use) 677 * r14 = ESR (data) or -1 (instruction) 678 * r13 = PACA 679 * r12 = TLB exception frame in PACA 680 * r11 = crap (free to use) 681 * r10 = crap (free to use) 682 * 683 * In addition we know that we will not re-enter, so in theory, we could 684 * use a simpler epilog not restoring SRR0/1 etc.. but we'll do that later. 685 * 686 * We also need to be careful about MAS registers here & TLB reservation, 687 * as we know we'll have clobbered them if we interrupt the main TLB miss 688 * handlers in which case we probably want to do a full restart at level 689 * 0 rather than saving / restoring the MAS. 690 * 691 * Note: If we care about performance of that core, we can easily shuffle 692 * a few things around 693 */ 694tlb_load_linear: 695 /* For now, we assume the linear mapping is contiguous and stops at 696 * linear_map_top. We also assume the size is a multiple of 1G, thus 697 * we only use 1G pages for now. That might have to be changed in a 698 * final implementation, especially when dealing with hypervisors 699 */ 700 __LOAD_PACA_TOC(r11) 701 LOAD_REG_ADDR_ALTTOC(r11, r11, linear_map_top) 702 ld r10,0(r11) 703 tovirt(10,10) 704 cmpld cr0,r16,r10 705 bge tlb_load_linear_fault 706 707 /* MAS1 need whole new setup. */ 708 li r15,(BOOK3E_PAGESZ_1GB<<MAS1_TSIZE_SHIFT) 709 oris r15,r15,MAS1_VALID@h /* MAS1 needs V and TSIZE */ 710 mtspr SPRN_MAS1,r15 711 712 /* Already somebody there ? */ 713 PPC_TLBSRX_DOT(0,R16) 714 beq tlb_load_linear_done 715 716 /* Now we build the remaining MAS. MAS0 and 2 should be fine 717 * with their defaults, which leaves us with MAS 3 and 7. The 718 * mapping is linear, so we just take the address, clear the 719 * region bits, and or in the permission bits which are currently 720 * hard wired 721 */ 722 clrrdi r10,r16,30 /* 1G page index */ 723 clrldi r10,r10,4 /* clear region bits */ 724 ori r10,r10,MAS3_SR|MAS3_SW|MAS3_SX 725 726 srdi r16,r10,32 727 mtspr SPRN_MAS3,r10 728 mtspr SPRN_MAS7,r16 729 730 tlbwe 731 732tlb_load_linear_done: 733 /* We use the "error" epilog for success as we do want to 734 * restore to the initial faulting context, whatever it was. 735 * We do that because we can't resume a fault within a TLB 736 * miss handler, due to MAS and TLB reservation being clobbered. 737 */ 738 TLB_MISS_EPILOG_ERROR 739 rfi 740 741tlb_load_linear_fault: 742 /* We keep the DEAR and ESR around, this shouldn't have happened */ 743 cmpdi cr0,r14,-1 744 beq 1f 745 TLB_MISS_EPILOG_ERROR_SPECIAL 746 b exc_data_storage_book3e 7471: TLB_MISS_EPILOG_ERROR_SPECIAL 748 b exc_instruction_storage_book3e 749