linux/arch/powerpc/mm/nohash/tlb_low_64e.S
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   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.endm
  75
  76.macro tlb_epilog_bolted
  77        ld      r14,EX_TLB_CR(r12)
  78#ifdef CONFIG_PPC_FSL_BOOK3E
  79        ld      r7,EX_TLB_R7(r12)
  80#endif
  81        ld      r10,EX_TLB_R10(r12)
  82        ld      r11,EX_TLB_R11(r12)
  83        ld      r13,EX_TLB_R13(r12)
  84        mtcr    r14
  85        ld      r14,EX_TLB_R14(r12)
  86        ld      r15,EX_TLB_R15(r12)
  87        ld      r16,EX_TLB_R16(r12)
  88        mfspr   r12,SPRN_SPRG_GEN_SCRATCH
  89.endm
  90
  91/* Data TLB miss */
  92        START_EXCEPTION(data_tlb_miss_bolted)
  93        tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
  94
  95        /* We need _PAGE_PRESENT and  _PAGE_ACCESSED set */
  96
  97        /* We do the user/kernel test for the PID here along with the RW test
  98         */
  99        /* We pre-test some combination of permissions to avoid double
 100         * faults:
 101         *
 102         * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
 103         * ESR_ST   is 0x00800000
 104         * _PAGE_BAP_SW is 0x00000010
 105         * So the shift is >> 19. This tests for supervisor writeability.
 106         * If the page happens to be supervisor writeable and not user
 107         * writeable, we will take a new fault later, but that should be
 108         * a rare enough case.
 109         *
 110         * We also move ESR_ST in _PAGE_DIRTY position
 111         * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
 112         *
 113         * MAS1 is preset for all we need except for TID that needs to
 114         * be cleared for kernel translations
 115         */
 116
 117        mfspr   r11,SPRN_ESR
 118
 119        srdi    r15,r16,60              /* get region */
 120        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
 121        bne-    dtlb_miss_fault_bolted  /* Bail if fault addr is invalid */
 122
 123        rlwinm  r10,r11,32-19,27,27
 124        rlwimi  r10,r11,32-16,19,19
 125        cmpwi   r15,0                   /* user vs kernel check */
 126        ori     r10,r10,_PAGE_PRESENT
 127        oris    r11,r10,_PAGE_ACCESSED@h
 128
 129        bne     tlb_miss_kernel_bolted
 130
 131tlb_miss_common_bolted:
 132/*
 133 * This is the guts of the TLB miss handler for bolted-linear.
 134 * We are entered with:
 135 *
 136 * r16 = faulting address
 137 * r15 = crap (free to use)
 138 * r14 = page table base
 139 * r13 = PACA
 140 * r11 = PTE permission mask
 141 * r10 = crap (free to use)
 142 */
 143        rldicl  r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
 144        cmpldi  cr0,r14,0
 145        clrrdi  r15,r15,3
 146        beq     tlb_miss_fault_bolted   /* No PGDIR, bail */
 147
 148BEGIN_MMU_FTR_SECTION
 149        /* Set the TLB reservation and search for existing entry. Then load
 150         * the entry.
 151         */
 152        PPC_TLBSRX_DOT(0,R16)
 153        ldx     r14,r14,r15             /* grab pgd entry */
 154        beq     tlb_miss_done_bolted    /* tlb exists already, bail */
 155MMU_FTR_SECTION_ELSE
 156        ldx     r14,r14,r15             /* grab pgd entry */
 157ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
 158
 159        rldicl  r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
 160        clrrdi  r15,r15,3
 161        cmpdi   cr0,r14,0
 162        bge     tlb_miss_fault_bolted   /* Bad pgd entry or hugepage; bail */
 163        ldx     r14,r14,r15             /* grab pud entry */
 164
 165        rldicl  r15,r16,64-PMD_SHIFT+3,64-PMD_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 pmd entry */
 170
 171        rldicl  r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3
 172        clrrdi  r15,r15,3
 173        cmpdi   cr0,r14,0
 174        bge     tlb_miss_fault_bolted
 175        ldx     r14,r14,r15             /* Grab PTE, normal (!huge) page */
 176
 177        /* Check if required permissions are met */
 178        andc.   r15,r11,r14
 179        rldicr  r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
 180        bne-    tlb_miss_fault_bolted
 181
 182        /* Now we build the MAS:
 183         *
 184         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
 185         * MAS 1   :    Almost fully setup
 186         *               - PID already updated by caller if necessary
 187         *               - TSIZE need change if !base page size, not
 188         *                 yet implemented for now
 189         * MAS 2   :    Defaults not useful, need to be redone
 190         * MAS 3+7 :    Needs to be done
 191         */
 192        clrrdi  r11,r16,12              /* Clear low crap in EA */
 193        clrldi  r15,r15,12              /* Clear crap at the top */
 194        rlwimi  r11,r14,32-19,27,31     /* Insert WIMGE */
 195        rlwimi  r15,r14,32-8,22,25      /* Move in U bits */
 196        mtspr   SPRN_MAS2,r11
 197        andi.   r11,r14,_PAGE_DIRTY
 198        rlwimi  r15,r14,32-2,26,31      /* Move in BAP bits */
 199
 200        /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
 201        bne     1f
 202        li      r11,MAS3_SW|MAS3_UW
 203        andc    r15,r15,r11
 2041:
 205        mtspr   SPRN_MAS7_MAS3,r15
 206        tlbwe
 207
 208tlb_miss_done_bolted:
 209        tlb_epilog_bolted
 210        rfi
 211
 212itlb_miss_kernel_bolted:
 213        li      r11,_PAGE_PRESENT|_PAGE_BAP_SX  /* Base perm */
 214        oris    r11,r11,_PAGE_ACCESSED@h
 215tlb_miss_kernel_bolted:
 216        mfspr   r10,SPRN_MAS1
 217        ld      r14,PACA_KERNELPGD(r13)
 218        cmpldi  cr0,r15,8               /* Check for vmalloc region */
 219        rlwinm  r10,r10,0,16,1          /* Clear TID */
 220        mtspr   SPRN_MAS1,r10
 221        beq+    tlb_miss_common_bolted
 222
 223tlb_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
 227dtlb_miss_fault_bolted:
 228        tlb_epilog_bolted
 229        b       exc_data_storage_book3e
 230itlb_miss_fault_bolted:
 231        tlb_epilog_bolted
 232        b       exc_instruction_storage_book3e
 233
 234/* Instruction TLB miss */
 235        START_EXCEPTION(instruction_tlb_miss_bolted)
 236        tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
 237
 238        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
 239        srdi    r15,r16,60              /* get region */
 240        bne-    itlb_miss_fault_bolted
 241
 242        li      r11,_PAGE_PRESENT|_PAGE_EXEC    /* Base perm */
 243
 244        /* We do the user/kernel test for the PID here along with the RW test
 245         */
 246
 247        cmpldi  cr0,r15,0                       /* Check for user region */
 248        oris    r11,r11,_PAGE_ACCESSED@h
 249        beq     tlb_miss_common_bolted
 250        b       itlb_miss_kernel_bolted
 251
 252#ifdef CONFIG_PPC_FSL_BOOK3E
 253/*
 254 * TLB miss handling for e6500 and derivatives, using hardware tablewalk.
 255 *
 256 * Linear mapping is bolted: no virtual page table or nested TLB misses
 257 * Indirect entries in TLB1, hardware loads resulting direct entries
 258 *    into TLB0
 259 * No HES or NV hint on TLB1, so we need to do software round-robin
 260 * No tlbsrx. so we need a spinlock, and we have to deal
 261 *    with MAS-damage caused by tlbsx
 262 * 4K pages only
 263 */
 264
 265        START_EXCEPTION(instruction_tlb_miss_e6500)
 266        tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
 267
 268        ld      r11,PACA_TCD_PTR(r13)
 269        srdi.   r15,r16,60              /* get region */
 270        ori     r16,r16,1
 271
 272        bne     tlb_miss_kernel_e6500   /* user/kernel test */
 273
 274        b       tlb_miss_common_e6500
 275
 276        START_EXCEPTION(data_tlb_miss_e6500)
 277        tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
 278
 279        ld      r11,PACA_TCD_PTR(r13)
 280        srdi.   r15,r16,60              /* get region */
 281        rldicr  r16,r16,0,62
 282
 283        bne     tlb_miss_kernel_e6500   /* user vs kernel check */
 284
 285/*
 286 * This is the guts of the TLB miss handler for e6500 and derivatives.
 287 * We are entered with:
 288 *
 289 * r16 = page of faulting address (low bit 0 if data, 1 if instruction)
 290 * r15 = crap (free to use)
 291 * r14 = page table base
 292 * r13 = PACA
 293 * r11 = tlb_per_core ptr
 294 * r10 = crap (free to use)
 295 * r7  = esel_next
 296 */
 297tlb_miss_common_e6500:
 298        crmove  cr2*4+2,cr0*4+2         /* cr2.eq != 0 if kernel address */
 299
 300BEGIN_FTR_SECTION               /* CPU_FTR_SMT */
 301        /*
 302         * Search if we already have an indirect entry for that virtual
 303         * address, and if we do, bail out.
 304         *
 305         * MAS6:IND should be already set based on MAS4
 306         */
 307        lhz     r10,PACAPACAINDEX(r13)
 308        addi    r10,r10,1
 309        crclr   cr1*4+eq        /* set cr1.eq = 0 for non-recursive */
 3101:      lbarx   r15,0,r11
 311        cmpdi   r15,0
 312        bne     2f
 313        stbcx.  r10,0,r11
 314        bne     1b
 3153:
 316        .subsection 1
 3172:      cmpd    cr1,r15,r10     /* recursive lock due to mcheck/crit/etc? */
 318        beq     cr1,3b          /* unlock will happen if cr1.eq = 0 */
 31910:     lbz     r15,0(r11)
 320        cmpdi   r15,0
 321        bne     10b
 322        b       1b
 323        .previous
 324END_FTR_SECTION_IFSET(CPU_FTR_SMT)
 325
 326        lbz     r7,TCD_ESEL_NEXT(r11)
 327
 328BEGIN_FTR_SECTION               /* CPU_FTR_SMT */
 329        /*
 330         * Erratum A-008139 says that we can't use tlbwe to change
 331         * an indirect entry in any way (including replacing or
 332         * invalidating) if the other thread could be in the process
 333         * of a lookup.  The workaround is to invalidate the entry
 334         * with tlbilx before overwriting.
 335         */
 336
 337        rlwinm  r10,r7,16,0xff0000
 338        oris    r10,r10,MAS0_TLBSEL(1)@h
 339        mtspr   SPRN_MAS0,r10
 340        isync
 341        tlbre
 342        mfspr   r15,SPRN_MAS1
 343        andis.  r15,r15,MAS1_VALID@h
 344        beq     5f
 345
 346BEGIN_FTR_SECTION_NESTED(532)
 347        mfspr   r10,SPRN_MAS8
 348        rlwinm  r10,r10,0,0x80000fff  /* tgs,tlpid -> sgs,slpid */
 349        mtspr   SPRN_MAS5,r10
 350END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
 351
 352        mfspr   r10,SPRN_MAS1
 353        rlwinm  r15,r10,0,0x3fff0000  /* tid -> spid */
 354        rlwimi  r15,r10,20,0x00000003 /* ind,ts -> sind,sas */
 355        mfspr   r10,SPRN_MAS6
 356        mtspr   SPRN_MAS6,r15
 357
 358        mfspr   r15,SPRN_MAS2
 359        isync
 360        tlbilxva 0,r15
 361        isync
 362
 363        mtspr   SPRN_MAS6,r10
 364
 3655:
 366BEGIN_FTR_SECTION_NESTED(532)
 367        li      r10,0
 368        mtspr   SPRN_MAS8,r10
 369        mtspr   SPRN_MAS5,r10
 370END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
 371
 372        tlbsx   0,r16
 373        mfspr   r10,SPRN_MAS1
 374        andis.  r15,r10,MAS1_VALID@h
 375        bne     tlb_miss_done_e6500
 376FTR_SECTION_ELSE
 377        mfspr   r10,SPRN_MAS1
 378ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT)
 379
 380        oris    r10,r10,MAS1_VALID@h
 381        beq     cr2,4f
 382        rlwinm  r10,r10,0,16,1          /* Clear TID */
 3834:      mtspr   SPRN_MAS1,r10
 384
 385        /* Now, we need to walk the page tables. First check if we are in
 386         * range.
 387         */
 388        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
 389        bne-    tlb_miss_fault_e6500
 390
 391        rldicl  r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
 392        cmpldi  cr0,r14,0
 393        clrrdi  r15,r15,3
 394        beq-    tlb_miss_fault_e6500 /* No PGDIR, bail */
 395        ldx     r14,r14,r15             /* grab pgd entry */
 396
 397        rldicl  r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
 398        clrrdi  r15,r15,3
 399        cmpdi   cr0,r14,0
 400        bge     tlb_miss_huge_e6500     /* Bad pgd entry or hugepage; bail */
 401        ldx     r14,r14,r15             /* grab pud entry */
 402
 403        rldicl  r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
 404        clrrdi  r15,r15,3
 405        cmpdi   cr0,r14,0
 406        bge     tlb_miss_huge_e6500
 407        ldx     r14,r14,r15             /* Grab pmd entry */
 408
 409        mfspr   r10,SPRN_MAS0
 410        cmpdi   cr0,r14,0
 411        bge     tlb_miss_huge_e6500
 412
 413        /* Now we build the MAS for a 2M indirect page:
 414         *
 415         * MAS 0   :    ESEL needs to be filled by software round-robin
 416         * MAS 1   :    Fully set up
 417         *               - PID already updated by caller if necessary
 418         *               - TSIZE for now is base ind page size always
 419         *               - TID already cleared if necessary
 420         * MAS 2   :    Default not 2M-aligned, need to be redone
 421         * MAS 3+7 :    Needs to be done
 422         */
 423
 424        ori     r14,r14,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
 425        mtspr   SPRN_MAS7_MAS3,r14
 426
 427        clrrdi  r15,r16,21              /* make EA 2M-aligned */
 428        mtspr   SPRN_MAS2,r15
 429
 430tlb_miss_huge_done_e6500:
 431        lbz     r16,TCD_ESEL_MAX(r11)
 432        lbz     r14,TCD_ESEL_FIRST(r11)
 433        rlwimi  r10,r7,16,0x00ff0000    /* insert esel_next into MAS0 */
 434        addi    r7,r7,1                 /* increment esel_next */
 435        mtspr   SPRN_MAS0,r10
 436        cmpw    r7,r16
 437        iseleq  r7,r14,r7               /* if next == last use first */
 438        stb     r7,TCD_ESEL_NEXT(r11)
 439
 440        tlbwe
 441
 442tlb_miss_done_e6500:
 443        .macro  tlb_unlock_e6500
 444BEGIN_FTR_SECTION
 445        beq     cr1,1f          /* no unlock if lock was recursively grabbed */
 446        li      r15,0
 447        isync
 448        stb     r15,0(r11)
 4491:
 450END_FTR_SECTION_IFSET(CPU_FTR_SMT)
 451        .endm
 452
 453        tlb_unlock_e6500
 454        tlb_epilog_bolted
 455        rfi
 456
 457tlb_miss_huge_e6500:
 458        beq     tlb_miss_fault_e6500
 459        li      r10,1
 460        andi.   r15,r14,HUGEPD_SHIFT_MASK@l /* r15 = psize */
 461        rldimi  r14,r10,63,0            /* Set PD_HUGE */
 462        xor     r14,r14,r15             /* Clear size bits */
 463        ldx     r14,0,r14
 464
 465        /*
 466         * Now we build the MAS for a huge page.
 467         *
 468         * MAS 0   :    ESEL needs to be filled by software round-robin
 469         *               - can be handled by indirect code
 470         * MAS 1   :    Need to clear IND and set TSIZE
 471         * MAS 2,3+7:   Needs to be redone similar to non-tablewalk handler
 472         */
 473
 474        subi    r15,r15,10              /* Convert psize to tsize */
 475        mfspr   r10,SPRN_MAS1
 476        rlwinm  r10,r10,0,~MAS1_IND
 477        rlwimi  r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK
 478        mtspr   SPRN_MAS1,r10
 479
 480        li      r10,-0x400
 481        sld     r15,r10,r15             /* Generate mask based on size */
 482        and     r10,r16,r15
 483        rldicr  r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
 484        rlwimi  r10,r14,32-19,27,31     /* Insert WIMGE */
 485        clrldi  r15,r15,PAGE_SHIFT      /* Clear crap at the top */
 486        rlwimi  r15,r14,32-8,22,25      /* Move in U bits */
 487        mtspr   SPRN_MAS2,r10
 488        andi.   r10,r14,_PAGE_DIRTY
 489        rlwimi  r15,r14,32-2,26,31      /* Move in BAP bits */
 490
 491        /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
 492        bne     1f
 493        li      r10,MAS3_SW|MAS3_UW
 494        andc    r15,r15,r10
 4951:
 496        mtspr   SPRN_MAS7_MAS3,r15
 497
 498        mfspr   r10,SPRN_MAS0
 499        b       tlb_miss_huge_done_e6500
 500
 501tlb_miss_kernel_e6500:
 502        ld      r14,PACA_KERNELPGD(r13)
 503        cmpldi  cr1,r15,8               /* Check for vmalloc region */
 504        beq+    cr1,tlb_miss_common_e6500
 505
 506tlb_miss_fault_e6500:
 507        tlb_unlock_e6500
 508        /* We need to check if it was an instruction miss */
 509        andi.   r16,r16,1
 510        bne     itlb_miss_fault_e6500
 511dtlb_miss_fault_e6500:
 512        tlb_epilog_bolted
 513        b       exc_data_storage_book3e
 514itlb_miss_fault_e6500:
 515        tlb_epilog_bolted
 516        b       exc_instruction_storage_book3e
 517#endif /* CONFIG_PPC_FSL_BOOK3E */
 518
 519/**********************************************************************
 520 *                                                                    *
 521 * TLB miss handling for Book3E with TLB reservation and HES support  *
 522 *                                                                    *
 523 **********************************************************************/
 524
 525
 526/* Data TLB miss */
 527        START_EXCEPTION(data_tlb_miss)
 528        TLB_MISS_PROLOG
 529
 530        /* Now we handle the fault proper. We only save DEAR in normal
 531         * fault case since that's the only interesting values here.
 532         * We could probably also optimize by not saving SRR0/1 in the
 533         * linear mapping case but I'll leave that for later
 534         */
 535        mfspr   r14,SPRN_ESR
 536        mfspr   r16,SPRN_DEAR           /* get faulting address */
 537        srdi    r15,r16,60              /* get region */
 538        cmpldi  cr0,r15,0xc             /* linear mapping ? */
 539        beq     tlb_load_linear         /* yes -> go to linear map load */
 540
 541        /* The page tables are mapped virtually linear. At this point, though,
 542         * we don't know whether we are trying to fault in a first level
 543         * virtual address or a virtual page table address. We can get that
 544         * from bit 0x1 of the region ID which we have set for a page table
 545         */
 546        andi.   r10,r15,0x1
 547        bne-    virt_page_table_tlb_miss
 548
 549        std     r14,EX_TLB_ESR(r12);    /* save ESR */
 550        std     r16,EX_TLB_DEAR(r12);   /* save DEAR */
 551
 552         /* We need _PAGE_PRESENT and  _PAGE_ACCESSED set */
 553        li      r11,_PAGE_PRESENT
 554        oris    r11,r11,_PAGE_ACCESSED@h
 555
 556        /* We do the user/kernel test for the PID here along with the RW test
 557         */
 558        cmpldi  cr0,r15,0               /* Check for user region */
 559
 560        /* We pre-test some combination of permissions to avoid double
 561         * faults:
 562         *
 563         * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
 564         * ESR_ST   is 0x00800000
 565         * _PAGE_BAP_SW is 0x00000010
 566         * So the shift is >> 19. This tests for supervisor writeability.
 567         * If the page happens to be supervisor writeable and not user
 568         * writeable, we will take a new fault later, but that should be
 569         * a rare enough case.
 570         *
 571         * We also move ESR_ST in _PAGE_DIRTY position
 572         * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
 573         *
 574         * MAS1 is preset for all we need except for TID that needs to
 575         * be cleared for kernel translations
 576         */
 577        rlwimi  r11,r14,32-19,27,27
 578        rlwimi  r11,r14,32-16,19,19
 579        beq     normal_tlb_miss
 580        /* XXX replace the RMW cycles with immediate loads + writes */
 5811:      mfspr   r10,SPRN_MAS1
 582        cmpldi  cr0,r15,8               /* Check for vmalloc region */
 583        rlwinm  r10,r10,0,16,1          /* Clear TID */
 584        mtspr   SPRN_MAS1,r10
 585        beq+    normal_tlb_miss
 586
 587        /* We got a crappy address, just fault with whatever DEAR and ESR
 588         * are here
 589         */
 590        TLB_MISS_EPILOG_ERROR
 591        b       exc_data_storage_book3e
 592
 593/* Instruction TLB miss */
 594        START_EXCEPTION(instruction_tlb_miss)
 595        TLB_MISS_PROLOG
 596
 597        /* If we take a recursive fault, the second level handler may need
 598         * to know whether we are handling a data or instruction fault in
 599         * order to get to the right store fault handler. We provide that
 600         * info by writing a crazy value in ESR in our exception frame
 601         */
 602        li      r14,-1  /* store to exception frame is done later */
 603
 604        /* Now we handle the fault proper. We only save DEAR in the non
 605         * linear mapping case since we know the linear mapping case will
 606         * not re-enter. We could indeed optimize and also not save SRR0/1
 607         * in the linear mapping case but I'll leave that for later
 608         *
 609         * Faulting address is SRR0 which is already in r16
 610         */
 611        srdi    r15,r16,60              /* get region */
 612        cmpldi  cr0,r15,0xc             /* linear mapping ? */
 613        beq     tlb_load_linear         /* yes -> go to linear map load */
 614
 615        /* We do the user/kernel test for the PID here along with the RW test
 616         */
 617        li      r11,_PAGE_PRESENT|_PAGE_EXEC    /* Base perm */
 618        oris    r11,r11,_PAGE_ACCESSED@h
 619
 620        cmpldi  cr0,r15,0                       /* Check for user region */
 621        std     r14,EX_TLB_ESR(r12)             /* write crazy -1 to frame */
 622        beq     normal_tlb_miss
 623
 624        li      r11,_PAGE_PRESENT|_PAGE_BAP_SX  /* Base perm */
 625        oris    r11,r11,_PAGE_ACCESSED@h
 626        /* XXX replace the RMW cycles with immediate loads + writes */
 627        mfspr   r10,SPRN_MAS1
 628        cmpldi  cr0,r15,8                       /* Check for vmalloc region */
 629        rlwinm  r10,r10,0,16,1                  /* Clear TID */
 630        mtspr   SPRN_MAS1,r10
 631        beq+    normal_tlb_miss
 632
 633        /* We got a crappy address, just fault */
 634        TLB_MISS_EPILOG_ERROR
 635        b       exc_instruction_storage_book3e
 636
 637/*
 638 * This is the guts of the first-level TLB miss handler for direct
 639 * misses. We are entered with:
 640 *
 641 * r16 = faulting address
 642 * r15 = region ID
 643 * r14 = crap (free to use)
 644 * r13 = PACA
 645 * r12 = TLB exception frame in PACA
 646 * r11 = PTE permission mask
 647 * r10 = crap (free to use)
 648 */
 649normal_tlb_miss:
 650        /* So we first construct the page table address. We do that by
 651         * shifting the bottom of the address (not the region ID) by
 652         * PAGE_SHIFT-3, clearing the bottom 3 bits (get a PTE ptr) and
 653         * or'ing the fourth high bit.
 654         *
 655         * NOTE: For 64K pages, we do things slightly differently in
 656         * order to handle the weird page table format used by linux
 657         */
 658        ori     r10,r15,0x1
 659        rldicl  r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4
 660        sldi    r15,r10,60
 661        clrrdi  r14,r14,3
 662        or      r10,r15,r14
 663
 664BEGIN_MMU_FTR_SECTION
 665        /* Set the TLB reservation and search for existing entry. Then load
 666         * the entry.
 667         */
 668        PPC_TLBSRX_DOT(0,R16)
 669        ld      r14,0(r10)
 670        beq     normal_tlb_miss_done
 671MMU_FTR_SECTION_ELSE
 672        ld      r14,0(r10)
 673ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
 674
 675finish_normal_tlb_miss:
 676        /* Check if required permissions are met */
 677        andc.   r15,r11,r14
 678        bne-    normal_tlb_miss_access_fault
 679
 680        /* Now we build the MAS:
 681         *
 682         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
 683         * MAS 1   :    Almost fully setup
 684         *               - PID already updated by caller if necessary
 685         *               - TSIZE need change if !base page size, not
 686         *                 yet implemented for now
 687         * MAS 2   :    Defaults not useful, need to be redone
 688         * MAS 3+7 :    Needs to be done
 689         *
 690         * TODO: mix up code below for better scheduling
 691         */
 692        clrrdi  r11,r16,12              /* Clear low crap in EA */
 693        rlwimi  r11,r14,32-19,27,31     /* Insert WIMGE */
 694        mtspr   SPRN_MAS2,r11
 695
 696        /* Check page size, if not standard, update MAS1 */
 697        rldicl  r11,r14,64-8,64-8
 698        cmpldi  cr0,r11,BOOK3E_PAGESZ_4K
 699        beq-    1f
 700        mfspr   r11,SPRN_MAS1
 701        rlwimi  r11,r14,31,21,24
 702        rlwinm  r11,r11,0,21,19
 703        mtspr   SPRN_MAS1,r11
 7041:
 705        /* Move RPN in position */
 706        rldicr  r11,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
 707        clrldi  r15,r11,12              /* Clear crap at the top */
 708        rlwimi  r15,r14,32-8,22,25      /* Move in U bits */
 709        rlwimi  r15,r14,32-2,26,31      /* Move in BAP bits */
 710
 711        /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
 712        andi.   r11,r14,_PAGE_DIRTY
 713        bne     1f
 714        li      r11,MAS3_SW|MAS3_UW
 715        andc    r15,r15,r11
 7161:
 717BEGIN_MMU_FTR_SECTION
 718        srdi    r16,r15,32
 719        mtspr   SPRN_MAS3,r15
 720        mtspr   SPRN_MAS7,r16
 721MMU_FTR_SECTION_ELSE
 722        mtspr   SPRN_MAS7_MAS3,r15
 723ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
 724
 725        tlbwe
 726
 727normal_tlb_miss_done:
 728        /* We don't bother with restoring DEAR or ESR since we know we are
 729         * level 0 and just going back to userland. They are only needed
 730         * if you are going to take an access fault
 731         */
 732        TLB_MISS_EPILOG_SUCCESS
 733        rfi
 734
 735normal_tlb_miss_access_fault:
 736        /* We need to check if it was an instruction miss */
 737        andi.   r10,r11,_PAGE_EXEC
 738        bne     1f
 739        ld      r14,EX_TLB_DEAR(r12)
 740        ld      r15,EX_TLB_ESR(r12)
 741        mtspr   SPRN_DEAR,r14
 742        mtspr   SPRN_ESR,r15
 743        TLB_MISS_EPILOG_ERROR
 744        b       exc_data_storage_book3e
 7451:      TLB_MISS_EPILOG_ERROR
 746        b       exc_instruction_storage_book3e
 747
 748
 749/*
 750 * This is the guts of the second-level TLB miss handler for direct
 751 * misses. We are entered with:
 752 *
 753 * r16 = virtual page table faulting address
 754 * r15 = region (top 4 bits of address)
 755 * r14 = crap (free to use)
 756 * r13 = PACA
 757 * r12 = TLB exception frame in PACA
 758 * r11 = crap (free to use)
 759 * r10 = crap (free to use)
 760 *
 761 * Note that this should only ever be called as a second level handler
 762 * with the current scheme when using SW load.
 763 * That means we can always get the original fault DEAR at
 764 * EX_TLB_DEAR-EX_TLB_SIZE(r12)
 765 *
 766 * It can be re-entered by the linear mapping miss handler. However, to
 767 * avoid too much complication, it will restart the whole fault at level
 768 * 0 so we don't care too much about clobbers
 769 *
 770 * XXX That code was written back when we couldn't clobber r14. We can now,
 771 * so we could probably optimize things a bit
 772 */
 773virt_page_table_tlb_miss:
 774        /* Are we hitting a kernel page table ? */
 775        andi.   r10,r15,0x8
 776
 777        /* The cool thing now is that r10 contains 0 for user and 8 for kernel,
 778         * and we happen to have the swapper_pg_dir at offset 8 from the user
 779         * pgdir in the PACA :-).
 780         */
 781        add     r11,r10,r13
 782
 783        /* If kernel, we need to clear MAS1 TID */
 784        beq     1f
 785        /* XXX replace the RMW cycles with immediate loads + writes */
 786        mfspr   r10,SPRN_MAS1
 787        rlwinm  r10,r10,0,16,1                  /* Clear TID */
 788        mtspr   SPRN_MAS1,r10
 7891:
 790BEGIN_MMU_FTR_SECTION
 791        /* Search if we already have a TLB entry for that virtual address, and
 792         * if we do, bail out.
 793         */
 794        PPC_TLBSRX_DOT(0,R16)
 795        beq     virt_page_table_tlb_miss_done
 796END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
 797
 798        /* Now, we need to walk the page tables. First check if we are in
 799         * range.
 800         */
 801        rldicl. r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4
 802        bne-    virt_page_table_tlb_miss_fault
 803
 804        /* Get the PGD pointer */
 805        ld      r15,PACAPGD(r11)
 806        cmpldi  cr0,r15,0
 807        beq-    virt_page_table_tlb_miss_fault
 808
 809        /* Get to PGD entry */
 810        rldicl  r11,r16,64-VPTE_PGD_SHIFT,64-PGD_INDEX_SIZE-3
 811        clrrdi  r10,r11,3
 812        ldx     r15,r10,r15
 813        cmpdi   cr0,r15,0
 814        bge     virt_page_table_tlb_miss_fault
 815
 816        /* Get to PUD entry */
 817        rldicl  r11,r16,64-VPTE_PUD_SHIFT,64-PUD_INDEX_SIZE-3
 818        clrrdi  r10,r11,3
 819        ldx     r15,r10,r15
 820        cmpdi   cr0,r15,0
 821        bge     virt_page_table_tlb_miss_fault
 822
 823        /* Get to PMD entry */
 824        rldicl  r11,r16,64-VPTE_PMD_SHIFT,64-PMD_INDEX_SIZE-3
 825        clrrdi  r10,r11,3
 826        ldx     r15,r10,r15
 827        cmpdi   cr0,r15,0
 828        bge     virt_page_table_tlb_miss_fault
 829
 830        /* Ok, we're all right, we can now create a kernel translation for
 831         * a 4K or 64K page from r16 -> r15.
 832         */
 833        /* Now we build the MAS:
 834         *
 835         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
 836         * MAS 1   :    Almost fully setup
 837         *               - PID already updated by caller if necessary
 838         *               - TSIZE for now is base page size always
 839         * MAS 2   :    Use defaults
 840         * MAS 3+7 :    Needs to be done
 841         *
 842         * So we only do MAS 2 and 3 for now...
 843         */
 844        clrldi  r11,r15,4               /* remove region ID from RPN */
 845        ori     r10,r11,1               /* Or-in SR */
 846
 847BEGIN_MMU_FTR_SECTION
 848        srdi    r16,r10,32
 849        mtspr   SPRN_MAS3,r10
 850        mtspr   SPRN_MAS7,r16
 851MMU_FTR_SECTION_ELSE
 852        mtspr   SPRN_MAS7_MAS3,r10
 853ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
 854
 855        tlbwe
 856
 857BEGIN_MMU_FTR_SECTION
 858virt_page_table_tlb_miss_done:
 859
 860        /* We have overridden MAS2:EPN but currently our primary TLB miss
 861         * handler will always restore it so that should not be an issue,
 862         * if we ever optimize the primary handler to not write MAS2 on
 863         * some cases, we'll have to restore MAS2:EPN here based on the
 864         * original fault's DEAR. If we do that we have to modify the
 865         * ITLB miss handler to also store SRR0 in the exception frame
 866         * as DEAR.
 867         *
 868         * However, one nasty thing we did is we cleared the reservation
 869         * (well, potentially we did). We do a trick here thus if we
 870         * are not a level 0 exception (we interrupted the TLB miss) we
 871         * offset the return address by -4 in order to replay the tlbsrx
 872         * instruction there
 873         */
 874        subf    r10,r13,r12
 875        cmpldi  cr0,r10,PACA_EXTLB+EX_TLB_SIZE
 876        bne-    1f
 877        ld      r11,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
 878        addi    r10,r11,-4
 879        std     r10,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
 8801:
 881END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
 882        /* Return to caller, normal case */
 883        TLB_MISS_EPILOG_SUCCESS
 884        rfi
 885
 886virt_page_table_tlb_miss_fault:
 887        /* If we fault here, things are a little bit tricky. We need to call
 888         * either data or instruction store fault, and we need to retrieve
 889         * the original fault address and ESR (for data).
 890         *
 891         * The thing is, we know that in normal circumstances, this is
 892         * always called as a second level tlb miss for SW load or as a first
 893         * level TLB miss for HW load, so we should be able to peek at the
 894         * relevant information in the first exception frame in the PACA.
 895         *
 896         * However, we do need to double check that, because we may just hit
 897         * a stray kernel pointer or a userland attack trying to hit those
 898         * areas. If that is the case, we do a data fault. (We can't get here
 899         * from an instruction tlb miss anyway).
 900         *
 901         * Note also that when going to a fault, we must unwind the previous
 902         * level as well. Since we are doing that, we don't need to clear or
 903         * restore the TLB reservation neither.
 904         */
 905        subf    r10,r13,r12
 906        cmpldi  cr0,r10,PACA_EXTLB+EX_TLB_SIZE
 907        bne-    virt_page_table_tlb_miss_whacko_fault
 908
 909        /* We dig the original DEAR and ESR from slot 0 */
 910        ld      r15,EX_TLB_DEAR+PACA_EXTLB(r13)
 911        ld      r16,EX_TLB_ESR+PACA_EXTLB(r13)
 912
 913        /* We check for the "special" ESR value for instruction faults */
 914        cmpdi   cr0,r16,-1
 915        beq     1f
 916        mtspr   SPRN_DEAR,r15
 917        mtspr   SPRN_ESR,r16
 918        TLB_MISS_EPILOG_ERROR
 919        b       exc_data_storage_book3e
 9201:      TLB_MISS_EPILOG_ERROR
 921        b       exc_instruction_storage_book3e
 922
 923virt_page_table_tlb_miss_whacko_fault:
 924        /* The linear fault will restart everything so ESR and DEAR will
 925         * not have been clobbered, let's just fault with what we have
 926         */
 927        TLB_MISS_EPILOG_ERROR
 928        b       exc_data_storage_book3e
 929
 930
 931/**************************************************************
 932 *                                                            *
 933 * TLB miss handling for Book3E with hw page table support    *
 934 *                                                            *
 935 **************************************************************/
 936
 937
 938/* Data TLB miss */
 939        START_EXCEPTION(data_tlb_miss_htw)
 940        TLB_MISS_PROLOG
 941
 942        /* Now we handle the fault proper. We only save DEAR in normal
 943         * fault case since that's the only interesting values here.
 944         * We could probably also optimize by not saving SRR0/1 in the
 945         * linear mapping case but I'll leave that for later
 946         */
 947        mfspr   r14,SPRN_ESR
 948        mfspr   r16,SPRN_DEAR           /* get faulting address */
 949        srdi    r11,r16,60              /* get region */
 950        cmpldi  cr0,r11,0xc             /* linear mapping ? */
 951        beq     tlb_load_linear         /* yes -> go to linear map load */
 952
 953        /* We do the user/kernel test for the PID here along with the RW test
 954         */
 955        cmpldi  cr0,r11,0               /* Check for user region */
 956        ld      r15,PACAPGD(r13)        /* Load user pgdir */
 957        beq     htw_tlb_miss
 958
 959        /* XXX replace the RMW cycles with immediate loads + writes */
 9601:      mfspr   r10,SPRN_MAS1
 961        cmpldi  cr0,r11,8               /* Check for vmalloc region */
 962        rlwinm  r10,r10,0,16,1          /* Clear TID */
 963        mtspr   SPRN_MAS1,r10
 964        ld      r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */
 965        beq+    htw_tlb_miss
 966
 967        /* We got a crappy address, just fault with whatever DEAR and ESR
 968         * are here
 969         */
 970        TLB_MISS_EPILOG_ERROR
 971        b       exc_data_storage_book3e
 972
 973/* Instruction TLB miss */
 974        START_EXCEPTION(instruction_tlb_miss_htw)
 975        TLB_MISS_PROLOG
 976
 977        /* If we take a recursive fault, the second level handler may need
 978         * to know whether we are handling a data or instruction fault in
 979         * order to get to the right store fault handler. We provide that
 980         * info by keeping a crazy value for ESR in r14
 981         */
 982        li      r14,-1  /* store to exception frame is done later */
 983
 984        /* Now we handle the fault proper. We only save DEAR in the non
 985         * linear mapping case since we know the linear mapping case will
 986         * not re-enter. We could indeed optimize and also not save SRR0/1
 987         * in the linear mapping case but I'll leave that for later
 988         *
 989         * Faulting address is SRR0 which is already in r16
 990         */
 991        srdi    r11,r16,60              /* get region */
 992        cmpldi  cr0,r11,0xc             /* linear mapping ? */
 993        beq     tlb_load_linear         /* yes -> go to linear map load */
 994
 995        /* We do the user/kernel test for the PID here along with the RW test
 996         */
 997        cmpldi  cr0,r11,0                       /* Check for user region */
 998        ld      r15,PACAPGD(r13)                /* Load user pgdir */
 999        beq     htw_tlb_miss
1000
1001        /* XXX replace the RMW cycles with immediate loads + writes */
10021:      mfspr   r10,SPRN_MAS1
1003        cmpldi  cr0,r11,8                       /* Check for vmalloc region */
1004        rlwinm  r10,r10,0,16,1                  /* Clear TID */
1005        mtspr   SPRN_MAS1,r10
1006        ld      r15,PACA_KERNELPGD(r13)         /* Load kernel pgdir */
1007        beq+    htw_tlb_miss
1008
1009        /* We got a crappy address, just fault */
1010        TLB_MISS_EPILOG_ERROR
1011        b       exc_instruction_storage_book3e
1012
1013
1014/*
1015 * This is the guts of the second-level TLB miss handler for direct
1016 * misses. We are entered with:
1017 *
1018 * r16 = virtual page table faulting address
1019 * r15 = PGD pointer
1020 * r14 = ESR
1021 * r13 = PACA
1022 * r12 = TLB exception frame in PACA
1023 * r11 = crap (free to use)
1024 * r10 = crap (free to use)
1025 *
1026 * It can be re-entered by the linear mapping miss handler. However, to
1027 * avoid too much complication, it will save/restore things for us
1028 */
1029htw_tlb_miss:
1030        /* Search if we already have a TLB entry for that virtual address, and
1031         * if we do, bail out.
1032         *
1033         * MAS1:IND should be already set based on MAS4
1034         */
1035        PPC_TLBSRX_DOT(0,R16)
1036        beq     htw_tlb_miss_done
1037
1038        /* Now, we need to walk the page tables. First check if we are in
1039         * range.
1040         */
1041        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
1042        bne-    htw_tlb_miss_fault
1043
1044        /* Get the PGD pointer */
1045        cmpldi  cr0,r15,0
1046        beq-    htw_tlb_miss_fault
1047
1048        /* Get to PGD entry */
1049        rldicl  r11,r16,64-(PGDIR_SHIFT-3),64-PGD_INDEX_SIZE-3
1050        clrrdi  r10,r11,3
1051        ldx     r15,r10,r15
1052        cmpdi   cr0,r15,0
1053        bge     htw_tlb_miss_fault
1054
1055        /* Get to PUD entry */
1056        rldicl  r11,r16,64-(PUD_SHIFT-3),64-PUD_INDEX_SIZE-3
1057        clrrdi  r10,r11,3
1058        ldx     r15,r10,r15
1059        cmpdi   cr0,r15,0
1060        bge     htw_tlb_miss_fault
1061
1062        /* Get to PMD entry */
1063        rldicl  r11,r16,64-(PMD_SHIFT-3),64-PMD_INDEX_SIZE-3
1064        clrrdi  r10,r11,3
1065        ldx     r15,r10,r15
1066        cmpdi   cr0,r15,0
1067        bge     htw_tlb_miss_fault
1068
1069        /* Ok, we're all right, we can now create an indirect entry for
1070         * a 1M or 256M page.
1071         *
1072         * The last trick is now that because we use "half" pages for
1073         * the HTW (1M IND is 2K and 256M IND is 32K) we need to account
1074         * for an added LSB bit to the RPN. For 64K pages, there is no
1075         * problem as we already use 32K arrays (half PTE pages), but for
1076         * 4K page we need to extract a bit from the virtual address and
1077         * insert it into the "PA52" bit of the RPN.
1078         */
1079        rlwimi  r15,r16,32-9,20,20
1080        /* Now we build the MAS:
1081         *
1082         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
1083         * MAS 1   :    Almost fully setup
1084         *               - PID already updated by caller if necessary
1085         *               - TSIZE for now is base ind page size always
1086         * MAS 2   :    Use defaults
1087         * MAS 3+7 :    Needs to be done
1088         */
1089        ori     r10,r15,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
1090
1091BEGIN_MMU_FTR_SECTION
1092        srdi    r16,r10,32
1093        mtspr   SPRN_MAS3,r10
1094        mtspr   SPRN_MAS7,r16
1095MMU_FTR_SECTION_ELSE
1096        mtspr   SPRN_MAS7_MAS3,r10
1097ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
1098
1099        tlbwe
1100
1101htw_tlb_miss_done:
1102        /* We don't bother with restoring DEAR or ESR since we know we are
1103         * level 0 and just going back to userland. They are only needed
1104         * if you are going to take an access fault
1105         */
1106        TLB_MISS_EPILOG_SUCCESS
1107        rfi
1108
1109htw_tlb_miss_fault:
1110        /* We need to check if it was an instruction miss. We know this
1111         * though because r14 would contain -1
1112         */
1113        cmpdi   cr0,r14,-1
1114        beq     1f
1115        mtspr   SPRN_DEAR,r16
1116        mtspr   SPRN_ESR,r14
1117        TLB_MISS_EPILOG_ERROR
1118        b       exc_data_storage_book3e
11191:      TLB_MISS_EPILOG_ERROR
1120        b       exc_instruction_storage_book3e
1121
1122/*
1123 * This is the guts of "any" level TLB miss handler for kernel linear
1124 * mapping misses. We are entered with:
1125 *
1126 *
1127 * r16 = faulting address
1128 * r15 = crap (free to use)
1129 * r14 = ESR (data) or -1 (instruction)
1130 * r13 = PACA
1131 * r12 = TLB exception frame in PACA
1132 * r11 = crap (free to use)
1133 * r10 = crap (free to use)
1134 *
1135 * In addition we know that we will not re-enter, so in theory, we could
1136 * use a simpler epilog not restoring SRR0/1 etc.. but we'll do that later.
1137 *
1138 * We also need to be careful about MAS registers here & TLB reservation,
1139 * as we know we'll have clobbered them if we interrupt the main TLB miss
1140 * handlers in which case we probably want to do a full restart at level
1141 * 0 rather than saving / restoring the MAS.
1142 *
1143 * Note: If we care about performance of that core, we can easily shuffle
1144 *       a few things around
1145 */
1146tlb_load_linear:
1147        /* For now, we assume the linear mapping is contiguous and stops at
1148         * linear_map_top. We also assume the size is a multiple of 1G, thus
1149         * we only use 1G pages for now. That might have to be changed in a
1150         * final implementation, especially when dealing with hypervisors
1151         */
1152        ld      r11,PACATOC(r13)
1153        ld      r11,linear_map_top@got(r11)
1154        ld      r10,0(r11)
1155        tovirt(10,10)
1156        cmpld   cr0,r16,r10
1157        bge     tlb_load_linear_fault
1158
1159        /* MAS1 need whole new setup. */
1160        li      r15,(BOOK3E_PAGESZ_1GB<<MAS1_TSIZE_SHIFT)
1161        oris    r15,r15,MAS1_VALID@h    /* MAS1 needs V and TSIZE */
1162        mtspr   SPRN_MAS1,r15
1163
1164        /* Already somebody there ? */
1165        PPC_TLBSRX_DOT(0,R16)
1166        beq     tlb_load_linear_done
1167
1168        /* Now we build the remaining MAS. MAS0 and 2 should be fine
1169         * with their defaults, which leaves us with MAS 3 and 7. The
1170         * mapping is linear, so we just take the address, clear the
1171         * region bits, and or in the permission bits which are currently
1172         * hard wired
1173         */
1174        clrrdi  r10,r16,30              /* 1G page index */
1175        clrldi  r10,r10,4               /* clear region bits */
1176        ori     r10,r10,MAS3_SR|MAS3_SW|MAS3_SX
1177
1178BEGIN_MMU_FTR_SECTION
1179        srdi    r16,r10,32
1180        mtspr   SPRN_MAS3,r10
1181        mtspr   SPRN_MAS7,r16
1182MMU_FTR_SECTION_ELSE
1183        mtspr   SPRN_MAS7_MAS3,r10
1184ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
1185
1186        tlbwe
1187
1188tlb_load_linear_done:
1189        /* We use the "error" epilog for success as we do want to
1190         * restore to the initial faulting context, whatever it was.
1191         * We do that because we can't resume a fault within a TLB
1192         * miss handler, due to MAS and TLB reservation being clobbered.
1193         */
1194        TLB_MISS_EPILOG_ERROR
1195        rfi
1196
1197tlb_load_linear_fault:
1198        /* We keep the DEAR and ESR around, this shouldn't have happened */
1199        cmpdi   cr0,r14,-1
1200        beq     1f
1201        TLB_MISS_EPILOG_ERROR_SPECIAL
1202        b       exc_data_storage_book3e
12031:      TLB_MISS_EPILOG_ERROR_SPECIAL
1204        b       exc_instruction_storage_book3e
1205