/*
 *  Low level TLB miss handlers for Book3E
 *
 *  Copyright (C) 2008-2009
 *      Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 */

#include <asm/processor.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/cputable.h>
#include <asm/pgtable.h>
#include <asm/exception-64e.h>
#include <asm/ppc-opcode.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_booke_hv_asm.h>

#ifdef CONFIG_PPC_64K_PAGES
#define VPTE_PMD_SHIFT  (PTE_INDEX_SIZE+1)
#else
#define VPTE_PMD_SHIFT  (PTE_INDEX_SIZE)
#endif
#define VPTE_PUD_SHIFT  (VPTE_PMD_SHIFT + PMD_INDEX_SIZE)
#define VPTE_PGD_SHIFT  (VPTE_PUD_SHIFT + PUD_INDEX_SIZE)
#define VPTE_INDEX_SIZE (VPTE_PGD_SHIFT + PGD_INDEX_SIZE)

/**********************************************************************
 *                                                                    *
 * TLB miss handling for Book3E with a bolted linear mapping          *
 * No virtual page table, no nested TLB misses                        *
 *                                                                    *
 **********************************************************************/

/*
 * Note that, unlike non-bolted handlers, TLB_EXFRAME is not
 * modified by the TLB miss handlers themselves, since the TLB miss
 * handler code will not itself cause a recursive TLB miss.
 *
 * TLB_EXFRAME will be modified when crit/mc/debug exceptions are
 * entered/exited.
 */
.macro tlb_prolog_bolted intnum addr
        mtspr   SPRN_SPRG_GEN_SCRATCH,r12
        mfspr   r12,SPRN_SPRG_TLB_EXFRAME
        std     r13,EX_TLB_R13(r12)
        std     r10,EX_TLB_R10(r12)
        mfspr   r13,SPRN_SPRG_PACA

        mfcr    r10
        std     r11,EX_TLB_R11(r12)
#ifdef CONFIG_KVM_BOOKE_HV
BEGIN_FTR_SECTION
        mfspr   r11, SPRN_SRR1
END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
#endif
        DO_KVM  \intnum, SPRN_SRR1
        std     r16,EX_TLB_R16(r12)
        mfspr   r16,\addr               /* get faulting address */
        std     r14,EX_TLB_R14(r12)
        ld      r14,PACAPGD(r13)
        std     r15,EX_TLB_R15(r12)
        std     r10,EX_TLB_CR(r12)
#ifdef CONFIG_PPC_FSL_BOOK3E
        std     r7,EX_TLB_R7(r12)
#endif
        TLB_MISS_PROLOG_STATS
.endm

.macro tlb_epilog_bolted
        ld      r14,EX_TLB_CR(r12)
#ifdef CONFIG_PPC_FSL_BOOK3E
        ld      r7,EX_TLB_R7(r12)
#endif
        ld      r10,EX_TLB_R10(r12)
        ld      r11,EX_TLB_R11(r12)
        ld      r13,EX_TLB_R13(r12)
        mtcr    r14
        ld      r14,EX_TLB_R14(r12)
        ld      r15,EX_TLB_R15(r12)
        TLB_MISS_RESTORE_STATS
        ld      r16,EX_TLB_R16(r12)
        mfspr   r12,SPRN_SPRG_GEN_SCRATCH
.endm

/* Data TLB miss */
        START_EXCEPTION(data_tlb_miss_bolted)
        tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR

        /* We need _PAGE_PRESENT and  _PAGE_ACCESSED set */

        /* We do the user/kernel test for the PID here along with the RW test
         */
        /* We pre-test some combination of permissions to avoid double
         * faults:
         *
         * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
         * ESR_ST   is 0x00800000
         * _PAGE_BAP_SW is 0x00000010
         * So the shift is >> 19. This tests for supervisor writeability.
         * If the page happens to be supervisor writeable and not user
         * writeable, we will take a new fault later, but that should be
         * a rare enough case.
         *
         * We also move ESR_ST in _PAGE_DIRTY position
         * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
         *
         * MAS1 is preset for all we need except for TID that needs to
         * be cleared for kernel translations
         */

        mfspr   r11,SPRN_ESR

        srdi    r15,r16,60              /* get region */
        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
        bne-    dtlb_miss_fault_bolted  /* Bail if fault addr is invalid */

        rlwinm  r10,r11,32-19,27,27
        rlwimi  r10,r11,32-16,19,19
        cmpwi   r15,0                   /* user vs kernel check */
        ori     r10,r10,_PAGE_PRESENT
        oris    r11,r10,_PAGE_ACCESSED@h

        TLB_MISS_STATS_SAVE_INFO_BOLTED
        bne     tlb_miss_kernel_bolted

tlb_miss_common_bolted:
/*
 * This is the guts of the TLB miss handler for bolted-linear.
 * We are entered with:
 *
 * r16 = faulting address
 * r15 = crap (free to use)
 * r14 = page table base
 * r13 = PACA
 * r11 = PTE permission mask
 * r10 = crap (free to use)
 */
        rldicl  r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
        cmpldi  cr0,r14,0
        clrrdi  r15,r15,3
        beq     tlb_miss_fault_bolted   /* No PGDIR, bail */

BEGIN_MMU_FTR_SECTION
        /* Set the TLB reservation and search for existing entry. Then load
         * the entry.
         */
        PPC_TLBSRX_DOT(0,R16)
        ldx     r14,r14,r15             /* grab pgd entry */
        beq     tlb_miss_done_bolted    /* tlb exists already, bail */
MMU_FTR_SECTION_ELSE
        ldx     r14,r14,r15             /* grab pgd entry */
ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)

#ifndef CONFIG_PPC_64K_PAGES
        rldicl  r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
        clrrdi  r15,r15,3
        cmpdi   cr0,r14,0
        bge     tlb_miss_fault_bolted   /* Bad pgd entry or hugepage; bail */
        ldx     r14,r14,r15             /* grab pud entry */
#endif /* CONFIG_PPC_64K_PAGES */

        rldicl  r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
        clrrdi  r15,r15,3
        cmpdi   cr0,r14,0
        bge     tlb_miss_fault_bolted
        ldx     r14,r14,r15             /* Grab pmd entry */

        rldicl  r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3
        clrrdi  r15,r15,3
        cmpdi   cr0,r14,0
        bge     tlb_miss_fault_bolted
        ldx     r14,r14,r15             /* Grab PTE, normal (!huge) page */

        /* Check if required permissions are met */
        andc.   r15,r11,r14
        rldicr  r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
        bne-    tlb_miss_fault_bolted

        /* Now we build the MAS:
         *
         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
         * MAS 1   :    Almost fully setup
         *               - PID already updated by caller if necessary
         *               - TSIZE need change if !base page size, not
         *                 yet implemented for now
         * MAS 2   :    Defaults not useful, need to be redone
         * MAS 3+7 :    Needs to be done
         */
        clrrdi  r11,r16,12              /* Clear low crap in EA */
        clrldi  r15,r15,12              /* Clear crap at the top */
        rlwimi  r11,r14,32-19,27,31     /* Insert WIMGE */
        rlwimi  r15,r14,32-8,22,25      /* Move in U bits */
        mtspr   SPRN_MAS2,r11
        andi.   r11,r14,_PAGE_DIRTY
        rlwimi  r15,r14,32-2,26,31      /* Move in BAP bits */

        /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
        bne     1f
        li      r11,MAS3_SW|MAS3_UW
        andc    r15,r15,r11
1:
        mtspr   SPRN_MAS7_MAS3,r15
        tlbwe

tlb_miss_done_bolted:
        TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK)
        tlb_epilog_bolted
        rfi

itlb_miss_kernel_bolted:
        li      r11,_PAGE_PRESENT|_PAGE_BAP_SX  /* Base perm */
        oris    r11,r11,_PAGE_ACCESSED@h
tlb_miss_kernel_bolted:
        mfspr   r10,SPRN_MAS1
        ld      r14,PACA_KERNELPGD(r13)
        cmpldi  cr0,r15,8               /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1          /* Clear TID */
        mtspr   SPRN_MAS1,r10
        beq+    tlb_miss_common_bolted

tlb_miss_fault_bolted:
        /* We need to check if it was an instruction miss */
        andi.   r10,r11,_PAGE_EXEC|_PAGE_BAP_SX
        bne     itlb_miss_fault_bolted
dtlb_miss_fault_bolted:
        TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
        tlb_epilog_bolted
        b       exc_data_storage_book3e
itlb_miss_fault_bolted:
        TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
        tlb_epilog_bolted
        b       exc_instruction_storage_book3e

/* Instruction TLB miss */
        START_EXCEPTION(instruction_tlb_miss_bolted)
        tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0

        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
        srdi    r15,r16,60              /* get region */
        TLB_MISS_STATS_SAVE_INFO_BOLTED
        bne-    itlb_miss_fault_bolted

        li      r11,_PAGE_PRESENT|_PAGE_EXEC    /* Base perm */

        /* We do the user/kernel test for the PID here along with the RW test
         */

        cmpldi  cr0,r15,0                       /* Check for user region */
        oris    r11,r11,_PAGE_ACCESSED@h
        beq     tlb_miss_common_bolted
        b       itlb_miss_kernel_bolted

#ifdef CONFIG_PPC_FSL_BOOK3E
/*
 * TLB miss handling for e6500 and derivatives, using hardware tablewalk.
 *
 * Linear mapping is bolted: no virtual page table or nested TLB misses
 * Indirect entries in TLB1, hardware loads resulting direct entries
 *    into TLB0
 * No HES or NV hint on TLB1, so we need to do software round-robin
 * No tlbsrx. so we need a spinlock, and we have to deal
 *    with MAS-damage caused by tlbsx
 * 4K pages only
 */

        START_EXCEPTION(instruction_tlb_miss_e6500)
        tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0

        ld      r11,PACA_TCD_PTR(r13)
        srdi.   r15,r16,60              /* get region */
        ori     r16,r16,1

        TLB_MISS_STATS_SAVE_INFO_BOLTED
        bne     tlb_miss_kernel_e6500   /* user/kernel test */

        b       tlb_miss_common_e6500

        START_EXCEPTION(data_tlb_miss_e6500)
        tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR

        ld      r11,PACA_TCD_PTR(r13)
        srdi.   r15,r16,60              /* get region */
        rldicr  r16,r16,0,62

        TLB_MISS_STATS_SAVE_INFO_BOLTED
        bne     tlb_miss_kernel_e6500   /* user vs kernel check */

/*
 * This is the guts of the TLB miss handler for e6500 and derivatives.
 * We are entered with:
 *
 * r16 = page of faulting address (low bit 0 if data, 1 if instruction)
 * r15 = crap (free to use)
 * r14 = page table base
 * r13 = PACA
 * r11 = tlb_per_core ptr
 * r10 = crap (free to use)
 * r7  = esel_next
 */
tlb_miss_common_e6500:
        crmove  cr2*4+2,cr0*4+2         /* cr2.eq != 0 if kernel address */

BEGIN_FTR_SECTION               /* CPU_FTR_SMT */
        /*
         * Search if we already have an indirect entry for that virtual
         * address, and if we do, bail out.
         *
         * MAS6:IND should be already set based on MAS4
         */
        lhz     r10,PACAPACAINDEX(r13)
        addi    r10,r10,1
        crclr   cr1*4+eq        /* set cr1.eq = 0 for non-recursive */
1:      lbarx   r15,0,r11
        cmpdi   r15,0
        bne     2f
        stbcx.  r10,0,r11
        bne     1b
3:
        .subsection 1
2:      cmpd    cr1,r15,r10     /* recursive lock due to mcheck/crit/etc? */
        beq     cr1,3b          /* unlock will happen if cr1.eq = 0 */
10:     lbz     r15,0(r11)
        cmpdi   r15,0
        bne     10b
        b       1b
        .previous
END_FTR_SECTION_IFSET(CPU_FTR_SMT)

        lbz     r7,TCD_ESEL_NEXT(r11)

BEGIN_FTR_SECTION               /* CPU_FTR_SMT */
        /*
         * Erratum A-008139 says that we can't use tlbwe to change
         * an indirect entry in any way (including replacing or
         * invalidating) if the other thread could be in the process
         * of a lookup.  The workaround is to invalidate the entry
         * with tlbilx before overwriting.
         */

        rlwinm  r10,r7,16,0xff0000
        oris    r10,r10,MAS0_TLBSEL(1)@h
        mtspr   SPRN_MAS0,r10
        isync
        tlbre
        mfspr   r15,SPRN_MAS1
        andis.  r15,r15,MAS1_VALID@h
        beq     5f

BEGIN_FTR_SECTION_NESTED(532)
        mfspr   r10,SPRN_MAS8
        rlwinm  r10,r10,0,0x80000fff  /* tgs,tlpid -> sgs,slpid */
        mtspr   SPRN_MAS5,r10
END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)

        mfspr   r10,SPRN_MAS1
        rlwinm  r15,r10,0,0x3fff0000  /* tid -> spid */
        rlwimi  r15,r10,20,0x00000003 /* ind,ts -> sind,sas */
        mfspr   r10,SPRN_MAS6
        mtspr   SPRN_MAS6,r15

        mfspr   r15,SPRN_MAS2
        isync
        tlbilxva 0,r15
        isync

        mtspr   SPRN_MAS6,r10

5:
BEGIN_FTR_SECTION_NESTED(532)
        li      r10,0
        mtspr   SPRN_MAS8,r10
        mtspr   SPRN_MAS5,r10
END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)

        tlbsx   0,r16
        mfspr   r10,SPRN_MAS1
        andis.  r15,r10,MAS1_VALID@h
        bne     tlb_miss_done_e6500
FTR_SECTION_ELSE
        mfspr   r10,SPRN_MAS1
ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT)

        oris    r10,r10,MAS1_VALID@h
        beq     cr2,4f
        rlwinm  r10,r10,0,16,1          /* Clear TID */
4:      mtspr   SPRN_MAS1,r10

        /* Now, we need to walk the page tables. First check if we are in
         * range.
         */
        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
        bne-    tlb_miss_fault_e6500

        rldicl  r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
        cmpldi  cr0,r14,0
        clrrdi  r15,r15,3
        beq-    tlb_miss_fault_e6500 /* No PGDIR, bail */
        ldx     r14,r14,r15             /* grab pgd entry */

        rldicl  r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
        clrrdi  r15,r15,3
        cmpdi   cr0,r14,0
        bge     tlb_miss_huge_e6500     /* Bad pgd entry or hugepage; bail */
        ldx     r14,r14,r15             /* grab pud entry */

        rldicl  r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
        clrrdi  r15,r15,3
        cmpdi   cr0,r14,0
        bge     tlb_miss_huge_e6500
        ldx     r14,r14,r15             /* Grab pmd entry */

        mfspr   r10,SPRN_MAS0
        cmpdi   cr0,r14,0
        bge     tlb_miss_huge_e6500

        /* Now we build the MAS for a 2M indirect page:
         *
         * MAS 0   :    ESEL needs to be filled by software round-robin
         * MAS 1   :    Fully set up
         *               - PID already updated by caller if necessary
         *               - TSIZE for now is base ind page size always
         *               - TID already cleared if necessary
         * MAS 2   :    Default not 2M-aligned, need to be redone
         * MAS 3+7 :    Needs to be done
         */

        ori     r14,r14,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
        mtspr   SPRN_MAS7_MAS3,r14

        clrrdi  r15,r16,21              /* make EA 2M-aligned */
        mtspr   SPRN_MAS2,r15

tlb_miss_huge_done_e6500:
        lbz     r16,TCD_ESEL_MAX(r11)
        lbz     r14,TCD_ESEL_FIRST(r11)
        rlwimi  r10,r7,16,0x00ff0000    /* insert esel_next into MAS0 */
        addi    r7,r7,1                 /* increment esel_next */
        mtspr   SPRN_MAS0,r10
        cmpw    r7,r16
        iseleq  r7,r14,r7               /* if next == last use first */
        stb     r7,TCD_ESEL_NEXT(r11)

        tlbwe

tlb_miss_done_e6500:
        .macro  tlb_unlock_e6500
BEGIN_FTR_SECTION
        beq     cr1,1f          /* no unlock if lock was recursively grabbed */
        li      r15,0
        isync
        stb     r15,0(r11)
1:
END_FTR_SECTION_IFSET(CPU_FTR_SMT)
        .endm

        tlb_unlock_e6500
        TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK)
        tlb_epilog_bolted
        rfi

tlb_miss_huge_e6500:
        beq     tlb_miss_fault_e6500
        li      r10,1
        andi.   r15,r14,HUGEPD_SHIFT_MASK@l /* r15 = psize */
        rldimi  r14,r10,63,0            /* Set PD_HUGE */
        xor     r14,r14,r15             /* Clear size bits */
        ldx     r14,0,r14

        /*
         * Now we build the MAS for a huge page.
         *
         * MAS 0   :    ESEL needs to be filled by software round-robin
         *               - can be handled by indirect code
         * MAS 1   :    Need to clear IND and set TSIZE
         * MAS 2,3+7:   Needs to be redone similar to non-tablewalk handler
         */

        subi    r15,r15,10              /* Convert psize to tsize */
        mfspr   r10,SPRN_MAS1
        rlwinm  r10,r10,0,~MAS1_IND
        rlwimi  r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK
        mtspr   SPRN_MAS1,r10

        li      r10,-0x400
        sld     r15,r10,r15             /* Generate mask based on size */
        and     r10,r16,r15
        rldicr  r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
        rlwimi  r10,r14,32-19,27,31     /* Insert WIMGE */
        clrldi  r15,r15,PAGE_SHIFT      /* Clear crap at the top */
        rlwimi  r15,r14,32-8,22,25      /* Move in U bits */
        mtspr   SPRN_MAS2,r10
        andi.   r10,r14,_PAGE_DIRTY
        rlwimi  r15,r14,32-2,26,31      /* Move in BAP bits */

        /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
        bne     1f
        li      r10,MAS3_SW|MAS3_UW
        andc    r15,r15,r10
1:
        mtspr   SPRN_MAS7_MAS3,r15

        mfspr   r10,SPRN_MAS0
        b       tlb_miss_huge_done_e6500

tlb_miss_kernel_e6500:
        ld      r14,PACA_KERNELPGD(r13)
        cmpldi  cr1,r15,8               /* Check for vmalloc region */
        beq+    cr1,tlb_miss_common_e6500

tlb_miss_fault_e6500:
        tlb_unlock_e6500
        /* We need to check if it was an instruction miss */
        andi.   r16,r16,1
        bne     itlb_miss_fault_e6500
dtlb_miss_fault_e6500:
        TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
        tlb_epilog_bolted
        b       exc_data_storage_book3e
itlb_miss_fault_e6500:
        TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
        tlb_epilog_bolted
        b       exc_instruction_storage_book3e
#endif /* CONFIG_PPC_FSL_BOOK3E */

/**********************************************************************
 *                                                                    *
 * TLB miss handling for Book3E with TLB reservation and HES support  *
 *                                                                    *
 **********************************************************************/


/* Data TLB miss */
        START_EXCEPTION(data_tlb_miss)
        TLB_MISS_PROLOG

        /* Now we handle the fault proper. We only save DEAR in normal
         * fault case since that's the only interesting values here.
         * We could probably also optimize by not saving SRR0/1 in the
         * linear mapping case but I'll leave that for later
         */
        mfspr   r14,SPRN_ESR
        mfspr   r16,SPRN_DEAR           /* get faulting address */
        srdi    r15,r16,60              /* get region */
        cmpldi  cr0,r15,0xc             /* linear mapping ? */
        TLB_MISS_STATS_SAVE_INFO
        beq     tlb_load_linear         /* yes -> go to linear map load */

        /* The page tables are mapped virtually linear. At this point, though,
         * we don't know whether we are trying to fault in a first level
         * virtual address or a virtual page table address. We can get that
         * from bit 0x1 of the region ID which we have set for a page table
         */
        andi.   r10,r15,0x1
        bne-    virt_page_table_tlb_miss

        std     r14,EX_TLB_ESR(r12);    /* save ESR */
        std     r16,EX_TLB_DEAR(r12);   /* save DEAR */

         /* We need _PAGE_PRESENT and  _PAGE_ACCESSED set */
        li      r11,_PAGE_PRESENT
        oris    r11,r11,_PAGE_ACCESSED@h

        /* We do the user/kernel test for the PID here along with the RW test
         */
        cmpldi  cr0,r15,0               /* Check for user region */

        /* We pre-test some combination of permissions to avoid double
         * faults:
         *
         * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
         * ESR_ST   is 0x00800000
         * _PAGE_BAP_SW is 0x00000010
         * So the shift is >> 19. This tests for supervisor writeability.
         * If the page happens to be supervisor writeable and not user
         * writeable, we will take a new fault later, but that should be
         * a rare enough case.
         *
         * We also move ESR_ST in _PAGE_DIRTY position
         * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
         *
         * MAS1 is preset for all we need except for TID that needs to
         * be cleared for kernel translations
         */
        rlwimi  r11,r14,32-19,27,27
        rlwimi  r11,r14,32-16,19,19
        beq     normal_tlb_miss
        /* XXX replace the RMW cycles with immediate loads + writes */
1:      mfspr   r10,SPRN_MAS1
        cmpldi  cr0,r15,8               /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1          /* Clear TID */
        mtspr   SPRN_MAS1,r10
        beq+    normal_tlb_miss

        /* We got a crappy address, just fault with whatever DEAR and ESR
         * are here
         */
        TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_data_storage_book3e

/* Instruction TLB miss */
        START_EXCEPTION(instruction_tlb_miss)
        TLB_MISS_PROLOG

        /* If we take a recursive fault, the second level handler may need
         * to know whether we are handling a data or instruction fault in
         * order to get to the right store fault handler. We provide that
         * info by writing a crazy value in ESR in our exception frame
         */
        li      r14,-1  /* store to exception frame is done later */

        /* Now we handle the fault proper. We only save DEAR in the non
         * linear mapping case since we know the linear mapping case will
         * not re-enter. We could indeed optimize and also not save SRR0/1
         * in the linear mapping case but I'll leave that for later
         *
         * Faulting address is SRR0 which is already in r16
         */
        srdi    r15,r16,60              /* get region */
        cmpldi  cr0,r15,0xc             /* linear mapping ? */
        TLB_MISS_STATS_SAVE_INFO
        beq     tlb_load_linear         /* yes -> go to linear map load */

        /* We do the user/kernel test for the PID here along with the RW test
         */
        li      r11,_PAGE_PRESENT|_PAGE_EXEC    /* Base perm */
        oris    r11,r11,_PAGE_ACCESSED@h

        cmpldi  cr0,r15,0                       /* Check for user region */
        std     r14,EX_TLB_ESR(r12)             /* write crazy -1 to frame */
        beq     normal_tlb_miss

        li      r11,_PAGE_PRESENT|_PAGE_BAP_SX  /* Base perm */
        oris    r11,r11,_PAGE_ACCESSED@h
        /* XXX replace the RMW cycles with immediate loads + writes */
        mfspr   r10,SPRN_MAS1
        cmpldi  cr0,r15,8                       /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1                  /* Clear TID */
        mtspr   SPRN_MAS1,r10
        beq+    normal_tlb_miss

        /* We got a crappy address, just fault */
        TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_instruction_storage_book3e

/*
 * This is the guts of the first-level TLB miss handler for direct
 * misses. We are entered with:
 *
 * r16 = faulting address
 * r15 = region ID
 * r14 = crap (free to use)
 * r13 = PACA
 * r12 = TLB exception frame in PACA
 * r11 = PTE permission mask
 * r10 = crap (free to use)
 */
normal_tlb_miss:
        /* So we first construct the page table address. We do that by
         * shifting the bottom of the address (not the region ID) by
         * PAGE_SHIFT-3, clearing the bottom 3 bits (get a PTE ptr) and
         * or'ing the fourth high bit.
         *
         * NOTE: For 64K pages, we do things slightly differently in
         * order to handle the weird page table format used by linux
         */
        ori     r10,r15,0x1
#ifdef CONFIG_PPC_64K_PAGES
        /* For the top bits, 16 bytes per PTE */
        rldicl  r14,r16,64-(PAGE_SHIFT-4),PAGE_SHIFT-4+4
        /* Now create the bottom bits as 0 in position 0x8000 and
         * the rest calculated for 8 bytes per PTE
         */
        rldicl  r15,r16,64-(PAGE_SHIFT-3),64-15
        /* Insert the bottom bits in */
        rlwimi  r14,r15,0,16,31
#else
        rldicl  r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4
#endif
        sldi    r15,r10,60
        clrrdi  r14,r14,3
        or      r10,r15,r14

BEGIN_MMU_FTR_SECTION
        /* Set the TLB reservation and search for existing entry. Then load
         * the entry.
         */
        PPC_TLBSRX_DOT(0,R16)
        ld      r14,0(r10)
        beq     normal_tlb_miss_done
MMU_FTR_SECTION_ELSE
        ld      r14,0(r10)
ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)

finish_normal_tlb_miss:
        /* Check if required permissions are met */
        andc.   r15,r11,r14
        bne-    normal_tlb_miss_access_fault

        /* Now we build the MAS:
         *
         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
         * MAS 1   :    Almost fully setup
         *               - PID already updated by caller if necessary
         *               - TSIZE need change if !base page size, not
         *                 yet implemented for now
         * MAS 2   :    Defaults not useful, need to be redone
         * MAS 3+7 :    Needs to be done
         *
         * TODO: mix up code below for better scheduling
         */
        clrrdi  r11,r16,12              /* Clear low crap in EA */
        rlwimi  r11,r14,32-19,27,31     /* Insert WIMGE */
        mtspr   SPRN_MAS2,r11

        /* Check page size, if not standard, update MAS1 */
        rldicl  r11,r14,64-8,64-8
#ifdef CONFIG_PPC_64K_PAGES
        cmpldi  cr0,r11,BOOK3E_PAGESZ_64K
#else
        cmpldi  cr0,r11,BOOK3E_PAGESZ_4K
#endif
        beq-    1f
        mfspr   r11,SPRN_MAS1
        rlwimi  r11,r14,31,21,24
        rlwinm  r11,r11,0,21,19
        mtspr   SPRN_MAS1,r11
1:
        /* Move RPN in position */
        rldicr  r11,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
        clrldi  r15,r11,12              /* Clear crap at the top */
        rlwimi  r15,r14,32-8,22,25      /* Move in U bits */
        rlwimi  r15,r14,32-2,26,31      /* Move in BAP bits */

        /* Mask out SW and UW if !DIRTY (XXX optimize this !) */
        andi.   r11,r14,_PAGE_DIRTY
        bne     1f
        li      r11,MAS3_SW|MAS3_UW
        andc    r15,r15,r11
1:
BEGIN_MMU_FTR_SECTION
        srdi    r16,r15,32
        mtspr   SPRN_MAS3,r15
        mtspr   SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
        mtspr   SPRN_MAS7_MAS3,r15
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)

        tlbwe

normal_tlb_miss_done:
        /* We don't bother with restoring DEAR or ESR since we know we are
         * level 0 and just going back to userland. They are only needed
         * if you are going to take an access fault
         */
        TLB_MISS_STATS_X(MMSTAT_TLB_MISS_NORM_OK)
        TLB_MISS_EPILOG_SUCCESS
        rfi

normal_tlb_miss_access_fault:
        /* We need to check if it was an instruction miss */
        andi.   r10,r11,_PAGE_EXEC
        bne     1f
        ld      r14,EX_TLB_DEAR(r12)
        ld      r15,EX_TLB_ESR(r12)
        mtspr   SPRN_DEAR,r14
        mtspr   SPRN_ESR,r15
        TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_data_storage_book3e
1:      TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_instruction_storage_book3e


/*
 * This is the guts of the second-level TLB miss handler for direct
 * misses. We are entered with:
 *
 * r16 = virtual page table faulting address
 * r15 = region (top 4 bits of address)
 * r14 = crap (free to use)
 * r13 = PACA
 * r12 = TLB exception frame in PACA
 * r11 = crap (free to use)
 * r10 = crap (free to use)
 *
 * Note that this should only ever be called as a second level handler
 * with the current scheme when using SW load.
 * That means we can always get the original fault DEAR at
 * EX_TLB_DEAR-EX_TLB_SIZE(r12)
 *
 * It can be re-entered by the linear mapping miss handler. However, to
 * avoid too much complication, it will restart the whole fault at level
 * 0 so we don't care too much about clobbers
 *
 * XXX That code was written back when we couldn't clobber r14. We can now,
 * so we could probably optimize things a bit
 */
virt_page_table_tlb_miss:
        /* Are we hitting a kernel page table ? */
        andi.   r10,r15,0x8

        /* The cool thing now is that r10 contains 0 for user and 8 for kernel,
         * and we happen to have the swapper_pg_dir at offset 8 from the user
         * pgdir in the PACA :-).
         */
        add     r11,r10,r13

        /* If kernel, we need to clear MAS1 TID */
        beq     1f
        /* XXX replace the RMW cycles with immediate loads + writes */
        mfspr   r10,SPRN_MAS1
        rlwinm  r10,r10,0,16,1                  /* Clear TID */
        mtspr   SPRN_MAS1,r10
1:
BEGIN_MMU_FTR_SECTION
        /* Search if we already have a TLB entry for that virtual address, and
         * if we do, bail out.
         */
        PPC_TLBSRX_DOT(0,R16)
        beq     virt_page_table_tlb_miss_done
END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)

        /* Now, we need to walk the page tables. First check if we are in
         * range.
         */
        rldicl. r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4
        bne-    virt_page_table_tlb_miss_fault

        /* Get the PGD pointer */
        ld      r15,PACAPGD(r11)
        cmpldi  cr0,r15,0
        beq-    virt_page_table_tlb_miss_fault

        /* Get to PGD entry */
        rldicl  r11,r16,64-VPTE_PGD_SHIFT,64-PGD_INDEX_SIZE-3
        clrrdi  r10,r11,3
        ldx     r15,r10,r15
        cmpdi   cr0,r15,0
        bge     virt_page_table_tlb_miss_fault

#ifndef CONFIG_PPC_64K_PAGES
        /* Get to PUD entry */
        rldicl  r11,r16,64-VPTE_PUD_SHIFT,64-PUD_INDEX_SIZE-3
        clrrdi  r10,r11,3
        ldx     r15,r10,r15
        cmpdi   cr0,r15,0
        bge     virt_page_table_tlb_miss_fault
#endif /* CONFIG_PPC_64K_PAGES */

        /* Get to PMD entry */
        rldicl  r11,r16,64-VPTE_PMD_SHIFT,64-PMD_INDEX_SIZE-3
        clrrdi  r10,r11,3
        ldx     r15,r10,r15
        cmpdi   cr0,r15,0
        bge     virt_page_table_tlb_miss_fault

        /* Ok, we're all right, we can now create a kernel translation for
         * a 4K or 64K page from r16 -> r15.
         */
        /* Now we build the MAS:
         *
         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
         * MAS 1   :    Almost fully setup
         *               - PID already updated by caller if necessary
         *               - TSIZE for now is base page size always
         * MAS 2   :    Use defaults
         * MAS 3+7 :    Needs to be done
         *
         * So we only do MAS 2 and 3 for now...
         */
        clrldi  r11,r15,4               /* remove region ID from RPN */
        ori     r10,r11,1               /* Or-in SR */

BEGIN_MMU_FTR_SECTION
        srdi    r16,r10,32
        mtspr   SPRN_MAS3,r10
        mtspr   SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
        mtspr   SPRN_MAS7_MAS3,r10
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)

        tlbwe

BEGIN_MMU_FTR_SECTION
virt_page_table_tlb_miss_done:

        /* We have overridden MAS2:EPN but currently our primary TLB miss
         * handler will always restore it so that should not be an issue,
         * if we ever optimize the primary handler to not write MAS2 on
         * some cases, we'll have to restore MAS2:EPN here based on the
         * original fault's DEAR. If we do that we have to modify the
         * ITLB miss handler to also store SRR0 in the exception frame
         * as DEAR.
         *
         * However, one nasty thing we did is we cleared the reservation
         * (well, potentially we did). We do a trick here thus if we
         * are not a level 0 exception (we interrupted the TLB miss) we
         * offset the return address by -4 in order to replay the tlbsrx
         * instruction there
         */
        subf    r10,r13,r12
        cmpldi  cr0,r10,PACA_EXTLB+EX_TLB_SIZE
        bne-    1f
        ld      r11,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
        addi    r10,r11,-4
        std     r10,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
1:
END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
        /* Return to caller, normal case */
        TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_OK);
        TLB_MISS_EPILOG_SUCCESS
        rfi

virt_page_table_tlb_miss_fault:
        /* If we fault here, things are a little bit tricky. We need to call
         * either data or instruction store fault, and we need to retrieve
         * the original fault address and ESR (for data).
         *
         * The thing is, we know that in normal circumstances, this is
         * always called as a second level tlb miss for SW load or as a first
         * level TLB miss for HW load, so we should be able to peek at the
         * relevant information in the first exception frame in the PACA.
         *
         * However, we do need to double check that, because we may just hit
         * a stray kernel pointer or a userland attack trying to hit those
         * areas. If that is the case, we do a data fault. (We can't get here
         * from an instruction tlb miss anyway).
         *
         * Note also that when going to a fault, we must unwind the previous
         * level as well. Since we are doing that, we don't need to clear or
         * restore the TLB reservation neither.
         */
        subf    r10,r13,r12
        cmpldi  cr0,r10,PACA_EXTLB+EX_TLB_SIZE
        bne-    virt_page_table_tlb_miss_whacko_fault

        /* We dig the original DEAR and ESR from slot 0 */
        ld      r15,EX_TLB_DEAR+PACA_EXTLB(r13)
        ld      r16,EX_TLB_ESR+PACA_EXTLB(r13)

        /* We check for the "special" ESR value for instruction faults */
        cmpdi   cr0,r16,-1
        beq     1f
        mtspr   SPRN_DEAR,r15
        mtspr   SPRN_ESR,r16
        TLB_MISS_STATS_D(MMSTAT_TLB_MISS_PT_FAULT);
        TLB_MISS_EPILOG_ERROR
        b       exc_data_storage_book3e
1:      TLB_MISS_STATS_I(MMSTAT_TLB_MISS_PT_FAULT);
        TLB_MISS_EPILOG_ERROR
        b       exc_instruction_storage_book3e

virt_page_table_tlb_miss_whacko_fault:
        /* The linear fault will restart everything so ESR and DEAR will
         * not have been clobbered, let's just fault with what we have
         */
        TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_FAULT);
        TLB_MISS_EPILOG_ERROR
        b       exc_data_storage_book3e


/**************************************************************
 *                                                            *
 * TLB miss handling for Book3E with hw page table support    *
 *                                                            *
 **************************************************************/


/* Data TLB miss */
        START_EXCEPTION(data_tlb_miss_htw)
        TLB_MISS_PROLOG

        /* Now we handle the fault proper. We only save DEAR in normal
         * fault case since that's the only interesting values here.
         * We could probably also optimize by not saving SRR0/1 in the
         * linear mapping case but I'll leave that for later
         */
        mfspr   r14,SPRN_ESR
        mfspr   r16,SPRN_DEAR           /* get faulting address */
        srdi    r11,r16,60              /* get region */
        cmpldi  cr0,r11,0xc             /* linear mapping ? */
        TLB_MISS_STATS_SAVE_INFO
        beq     tlb_load_linear         /* yes -> go to linear map load */

        /* We do the user/kernel test for the PID here along with the RW test
         */
        cmpldi  cr0,r11,0               /* Check for user region */
        ld      r15,PACAPGD(r13)        /* Load user pgdir */
        beq     htw_tlb_miss

        /* XXX replace the RMW cycles with immediate loads + writes */
1:      mfspr   r10,SPRN_MAS1
        cmpldi  cr0,r11,8               /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1          /* Clear TID */
        mtspr   SPRN_MAS1,r10
        ld      r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */
        beq+    htw_tlb_miss

        /* We got a crappy address, just fault with whatever DEAR and ESR
         * are here
         */
        TLB_MISS_STATS_D(MMSTAT_TLB_MISS_NORM_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_data_storage_book3e

/* Instruction TLB miss */
        START_EXCEPTION(instruction_tlb_miss_htw)
        TLB_MISS_PROLOG

        /* If we take a recursive fault, the second level handler may need
         * to know whether we are handling a data or instruction fault in
         * order to get to the right store fault handler. We provide that
         * info by keeping a crazy value for ESR in r14
         */
        li      r14,-1  /* store to exception frame is done later */

        /* Now we handle the fault proper. We only save DEAR in the non
         * linear mapping case since we know the linear mapping case will
         * not re-enter. We could indeed optimize and also not save SRR0/1
         * in the linear mapping case but I'll leave that for later
         *
         * Faulting address is SRR0 which is already in r16
         */
        srdi    r11,r16,60              /* get region */
        cmpldi  cr0,r11,0xc             /* linear mapping ? */
        TLB_MISS_STATS_SAVE_INFO
        beq     tlb_load_linear         /* yes -> go to linear map load */

        /* We do the user/kernel test for the PID here along with the RW test
         */
        cmpldi  cr0,r11,0                       /* Check for user region */
        ld      r15,PACAPGD(r13)                /* Load user pgdir */
        beq     htw_tlb_miss

        /* XXX replace the RMW cycles with immediate loads + writes */
1:      mfspr   r10,SPRN_MAS1
        cmpldi  cr0,r11,8                       /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1                  /* Clear TID */
        mtspr   SPRN_MAS1,r10
        ld      r15,PACA_KERNELPGD(r13)         /* Load kernel pgdir */
        beq+    htw_tlb_miss

        /* We got a crappy address, just fault */
        TLB_MISS_STATS_I(MMSTAT_TLB_MISS_NORM_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_instruction_storage_book3e


/*
 * This is the guts of the second-level TLB miss handler for direct
 * misses. We are entered with:
 *
 * r16 = virtual page table faulting address
 * r15 = PGD pointer
 * r14 = ESR
 * r13 = PACA
 * r12 = TLB exception frame in PACA
 * r11 = crap (free to use)
 * r10 = crap (free to use)
 *
 * It can be re-entered by the linear mapping miss handler. However, to
 * avoid too much complication, it will save/restore things for us
 */
htw_tlb_miss:
        /* Search if we already have a TLB entry for that virtual address, and
         * if we do, bail out.
         *
         * MAS1:IND should be already set based on MAS4
         */
        PPC_TLBSRX_DOT(0,R16)
        beq     htw_tlb_miss_done

        /* Now, we need to walk the page tables. First check if we are in
         * range.
         */
        rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
        bne-    htw_tlb_miss_fault

        /* Get the PGD pointer */
        cmpldi  cr0,r15,0
        beq-    htw_tlb_miss_fault

        /* Get to PGD entry */
        rldicl  r11,r16,64-(PGDIR_SHIFT-3),64-PGD_INDEX_SIZE-3
        clrrdi  r10,r11,3
        ldx     r15,r10,r15
        cmpdi   cr0,r15,0
        bge     htw_tlb_miss_fault

#ifndef CONFIG_PPC_64K_PAGES
        /* Get to PUD entry */
        rldicl  r11,r16,64-(PUD_SHIFT-3),64-PUD_INDEX_SIZE-3
        clrrdi  r10,r11,3
        ldx     r15,r10,r15
        cmpdi   cr0,r15,0
        bge     htw_tlb_miss_fault
#endif /* CONFIG_PPC_64K_PAGES */

        /* Get to PMD entry */
        rldicl  r11,r16,64-(PMD_SHIFT-3),64-PMD_INDEX_SIZE-3
        clrrdi  r10,r11,3
        ldx     r15,r10,r15
        cmpdi   cr0,r15,0
        bge     htw_tlb_miss_fault

        /* Ok, we're all right, we can now create an indirect entry for
         * a 1M or 256M page.
         *
         * The last trick is now that because we use "half" pages for
         * the HTW (1M IND is 2K and 256M IND is 32K) we need to account
         * for an added LSB bit to the RPN. For 64K pages, there is no
         * problem as we already use 32K arrays (half PTE pages), but for
         * 4K page we need to extract a bit from the virtual address and
         * insert it into the "PA52" bit of the RPN.
         */
#ifndef CONFIG_PPC_64K_PAGES
        rlwimi  r15,r16,32-9,20,20
#endif
        /* Now we build the MAS:
         *
         * MAS 0   :    Fully setup with defaults in MAS4 and TLBnCFG
         * MAS 1   :    Almost fully setup
         *               - PID already updated by caller if necessary
         *               - TSIZE for now is base ind page size always
         * MAS 2   :    Use defaults
         * MAS 3+7 :    Needs to be done
         */
#ifdef CONFIG_PPC_64K_PAGES
        ori     r10,r15,(BOOK3E_PAGESZ_64K << MAS3_SPSIZE_SHIFT)
#else
        ori     r10,r15,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
#endif

BEGIN_MMU_FTR_SECTION
        srdi    r16,r10,32
        mtspr   SPRN_MAS3,r10
        mtspr   SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
        mtspr   SPRN_MAS7_MAS3,r10
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)

        tlbwe

htw_tlb_miss_done:
        /* We don't bother with restoring DEAR or ESR since we know we are
         * level 0 and just going back to userland. They are only needed
         * if you are going to take an access fault
         */
        TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_OK)
        TLB_MISS_EPILOG_SUCCESS
        rfi

htw_tlb_miss_fault:
        /* We need to check if it was an instruction miss. We know this
         * though because r14 would contain -1
         */
        cmpdi   cr0,r14,-1
        beq     1f
        mtspr   SPRN_DEAR,r16
        mtspr   SPRN_ESR,r14
        TLB_MISS_STATS_D(MMSTAT_TLB_MISS_PT_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_data_storage_book3e
1:      TLB_MISS_STATS_I(MMSTAT_TLB_MISS_PT_FAULT)
        TLB_MISS_EPILOG_ERROR
        b       exc_instruction_storage_book3e

/*
 * This is the guts of "any" level TLB miss handler for kernel linear
 * mapping misses. We are entered with:
 *
 *
 * r16 = faulting address
 * r15 = crap (free to use)
 * r14 = ESR (data) or -1 (instruction)
 * r13 = PACA
 * r12 = TLB exception frame in PACA
 * r11 = crap (free to use)
 * r10 = crap (free to use)
 *
 * In addition we know that we will not re-enter, so in theory, we could
 * use a simpler epilog not restoring SRR0/1 etc.. but we'll do that later.
 *
 * We also need to be careful about MAS registers here & TLB reservation,
 * as we know we'll have clobbered them if we interrupt the main TLB miss
 * handlers in which case we probably want to do a full restart at level
 * 0 rather than saving / restoring the MAS.
 *
 * Note: If we care about performance of that core, we can easily shuffle
 *       a few things around
 */
tlb_load_linear:
        /* For now, we assume the linear mapping is contiguous and stops at
         * linear_map_top. We also assume the size is a multiple of 1G, thus
         * we only use 1G pages for now. That might have to be changed in a
         * final implementation, especially when dealing with hypervisors
         */
        ld      r11,PACATOC(r13)
        ld      r11,linear_map_top@got(r11)
        ld      r10,0(r11)
        tovirt(10,10)
        cmpld   cr0,r16,r10
        bge     tlb_load_linear_fault

        /* MAS1 need whole new setup. */
        li      r15,(BOOK3E_PAGESZ_1GB<<MAS1_TSIZE_SHIFT)
        oris    r15,r15,MAS1_VALID@h    /* MAS1 needs V and TSIZE */
        mtspr   SPRN_MAS1,r15

        /* Already somebody there ? */
        PPC_TLBSRX_DOT(0,R16)
        beq     tlb_load_linear_done

        /* Now we build the remaining MAS. MAS0 and 2 should be fine
         * with their defaults, which leaves us with MAS 3 and 7. The
         * mapping is linear, so we just take the address, clear the
         * region bits, and or in the permission bits which are currently
         * hard wired
         */
        clrrdi  r10,r16,30              /* 1G page index */
        clrldi  r10,r10,4               /* clear region bits */
        ori     r10,r10,MAS3_SR|MAS3_SW|MAS3_SX

BEGIN_MMU_FTR_SECTION
        srdi    r16,r10,32
        mtspr   SPRN_MAS3,r10
        mtspr   SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
        mtspr   SPRN_MAS7_MAS3,r10
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)

        tlbwe

tlb_load_linear_done:
        /* We use the "error" epilog for success as we do want to
         * restore to the initial faulting context, whatever it was.
         * We do that because we can't resume a fault within a TLB
         * miss handler, due to MAS and TLB reservation being clobbered.
         */
        TLB_MISS_STATS_X(MMSTAT_TLB_MISS_LINEAR)
        TLB_MISS_EPILOG_ERROR
        rfi

tlb_load_linear_fault:
        /* We keep the DEAR and ESR around, this shouldn't have happened */
        cmpdi   cr0,r14,-1
        beq     1f
        TLB_MISS_EPILOG_ERROR_SPECIAL
        b       exc_data_storage_book3e
1:      TLB_MISS_EPILOG_ERROR_SPECIAL
        b       exc_instruction_storage_book3e


#ifdef CONFIG_BOOK3E_MMU_TLB_STATS
.tlb_stat_inc:
1:      ldarx   r8,0,r9
        addi    r8,r8,1
        stdcx.  r8,0,r9
        bne-    1b
        blr
#endif