[mirror_ubuntu-jammy-kernel.git] / arch / powerpc / kernel / exceptions-64s.S

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * This file contains the 64-bit "server" PowerPC variant
 * of the low level exception handling including exception
 * vectors, exception return, part of the slb and stab
 * handling and other fixed offset specific things.
 *
 * This file is meant to be #included from head_64.S due to
 * position dependent assembly.
 *
 * Most of this originates from head_64.S and thus has the same
 * copyright history.
 *
 */

#include <asm/hw_irq.h>
#include <asm/exception-64s.h>
#include <asm/ptrace.h>
#include <asm/cpuidle.h>
#include <asm/head-64.h>
#include <asm/feature-fixups.h>
#include <asm/kup.h>

/* PACA save area offsets (exgen, exmc, etc) */
#define EX_R9           0
#define EX_R10          8
#define EX_R11          16
#define EX_R12          24
#define EX_R13          32
#define EX_DAR          40
#define EX_DSISR        48
#define EX_CCR          52
#define EX_CFAR         56
#define EX_PPR          64
#define EX_CTR          72
.if EX_SIZE != 10
        .error "EX_SIZE is wrong"
.endif

/*
 * Following are fixed section helper macros.
 *
 * EXC_REAL_BEGIN/END  - real, unrelocated exception vectors
 * EXC_VIRT_BEGIN/END  - virt (AIL), unrelocated exception vectors
 * TRAMP_REAL_BEGIN    - real, unrelocated helpers (virt may call these)
 * TRAMP_VIRT_BEGIN    - virt, unreloc helpers (in practice, real can use)
 * EXC_COMMON          - After switching to virtual, relocated mode.
 */

#define EXC_REAL_BEGIN(name, start, size)                       \
        FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##name, start, size)

#define EXC_REAL_END(name, start, size)                         \
        FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##name, start, size)

#define EXC_VIRT_BEGIN(name, start, size)                       \
        FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)

#define EXC_VIRT_END(name, start, size)                         \
        FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)

#define EXC_COMMON_BEGIN(name)                                  \
        USE_TEXT_SECTION();                                     \
        .balign IFETCH_ALIGN_BYTES;                             \
        .global name;                                           \
        _ASM_NOKPROBE_SYMBOL(name);                             \
        DEFINE_FIXED_SYMBOL(name);                              \
name:

#define TRAMP_REAL_BEGIN(name)                                  \
        FIXED_SECTION_ENTRY_BEGIN(real_trampolines, name)

#define TRAMP_VIRT_BEGIN(name)                                  \
        FIXED_SECTION_ENTRY_BEGIN(virt_trampolines, name)

#define EXC_REAL_NONE(start, size)                              \
        FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##unused, start, size); \
        FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##unused, start, size)

#define EXC_VIRT_NONE(start, size)                              \
        FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size); \
        FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size)

/*
 * We're short on space and time in the exception prolog, so we can't
 * use the normal LOAD_REG_IMMEDIATE macro to load the address of label.
 * Instead we get the base of the kernel from paca->kernelbase and or in the low
 * part of label. This requires that the label be within 64KB of kernelbase, and
 * that kernelbase be 64K aligned.
 */
#define LOAD_HANDLER(reg, label)                                        \
        ld      reg,PACAKBASE(r13);     /* get high part of &label */   \
        ori     reg,reg,FIXED_SYMBOL_ABS_ADDR(label)

#define __LOAD_HANDLER(reg, label)                                      \
        ld      reg,PACAKBASE(r13);                                     \
        ori     reg,reg,(ABS_ADDR(label))@l

/*
 * Branches from unrelocated code (e.g., interrupts) to labels outside
 * head-y require >64K offsets.
 */
#define __LOAD_FAR_HANDLER(reg, label)                                  \
        ld      reg,PACAKBASE(r13);                                     \
        ori     reg,reg,(ABS_ADDR(label))@l;                            \
        addis   reg,reg,(ABS_ADDR(label))@h

/*
 * Branch to label using its 0xC000 address. This results in instruction
 * address suitable for MSR[IR]=0 or 1, which allows relocation to be turned
 * on using mtmsr rather than rfid.
 *
 * This could set the 0xc bits for !RELOCATABLE as an immediate, rather than
 * load KBASE for a slight optimisation.
 */
#define BRANCH_TO_C000(reg, label)                                      \
        __LOAD_FAR_HANDLER(reg, label);                                 \
        mtctr   reg;                                                    \
        bctr

/*
 * Interrupt code generation macros
 */
#define IVEC            .L_IVEC_\name\()        /* Interrupt vector address */
#define IHSRR           .L_IHSRR_\name\()       /* Sets SRR or HSRR registers */
#define IHSRR_IF_HVMODE .L_IHSRR_IF_HVMODE_\name\() /* HSRR if HV else SRR */
#define IAREA           .L_IAREA_\name\()       /* PACA save area */
#define IVIRT           .L_IVIRT_\name\()       /* Has virt mode entry point */
#define IISIDE          .L_IISIDE_\name\()      /* Uses SRR0/1 not DAR/DSISR */
#define IDAR            .L_IDAR_\name\()        /* Uses DAR (or SRR0) */
#define IDSISR          .L_IDSISR_\name\()      /* Uses DSISR (or SRR1) */
#define ISET_RI         .L_ISET_RI_\name\()     /* Run common code w/ MSR[RI]=1 */
#define IBRANCH_TO_COMMON       .L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
#define IREALMODE_COMMON        .L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
#define IMASK           .L_IMASK_\name\()       /* IRQ soft-mask bit */
#define IKVM_SKIP       .L_IKVM_SKIP_\name\()   /* Generate KVM skip handler */
#define IKVM_REAL       .L_IKVM_REAL_\name\()   /* Real entry tests KVM */
#define __IKVM_REAL(name)       .L_IKVM_REAL_ ## name
#define IKVM_VIRT       .L_IKVM_VIRT_\name\()   /* Virt entry tests KVM */
#define ISTACK          .L_ISTACK_\name\()      /* Set regular kernel stack */
#define __ISTACK(name)  .L_ISTACK_ ## name
#define IRECONCILE      .L_IRECONCILE_\name\()  /* Do RECONCILE_IRQ_STATE */
#define IKUAP           .L_IKUAP_\name\()       /* Do KUAP lock */

#define INT_DEFINE_BEGIN(n)                                             \
.macro int_define_ ## n name

#define INT_DEFINE_END(n)                                               \
.endm ;                                                                 \
int_define_ ## n n ;                                                    \
do_define_int n

.macro do_define_int name
        .ifndef IVEC
                .error "IVEC not defined"
        .endif
        .ifndef IHSRR
                IHSRR=0
        .endif
        .ifndef IHSRR_IF_HVMODE
                IHSRR_IF_HVMODE=0
        .endif
        .ifndef IAREA
                IAREA=PACA_EXGEN
        .endif
        .ifndef IVIRT
                IVIRT=1
        .endif
        .ifndef IISIDE
                IISIDE=0
        .endif
        .ifndef IDAR
                IDAR=0
        .endif
        .ifndef IDSISR
                IDSISR=0
        .endif
        .ifndef ISET_RI
                ISET_RI=1
        .endif
        .ifndef IBRANCH_TO_COMMON
                IBRANCH_TO_COMMON=1
        .endif
        .ifndef IREALMODE_COMMON
                IREALMODE_COMMON=0
        .else
                .if ! IBRANCH_TO_COMMON
                        .error "IREALMODE_COMMON=1 but IBRANCH_TO_COMMON=0"
                .endif
        .endif
        .ifndef IMASK
                IMASK=0
        .endif
        .ifndef IKVM_SKIP
                IKVM_SKIP=0
        .endif
        .ifndef IKVM_REAL
                IKVM_REAL=0
        .endif
        .ifndef IKVM_VIRT
                IKVM_VIRT=0
        .endif
        .ifndef ISTACK
                ISTACK=1
        .endif
        .ifndef IRECONCILE
                IRECONCILE=1
        .endif
        .ifndef IKUAP
                IKUAP=1
        .endif
.endm

#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/*
 * All interrupts which set HSRR registers, as well as SRESET and MCE and
 * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
 * so they all generally need to test whether they were taken in guest context.
 *
 * Note: SRESET and MCE may also be sent to the guest by the hypervisor, and be
 * taken with MSR[HV]=0.
 *
 * Interrupts which set SRR registers (with the above exceptions) do not
 * elevate to MSR[HV]=1 mode, though most can be taken when running with
 * MSR[HV]=1  (e.g., bare metal kernel and userspace). So these interrupts do
 * not need to test whether a guest is running because they get delivered to
 * the guest directly, including nested HV KVM guests.
 *
 * The exception is PR KVM, where the guest runs with MSR[PR]=1 and the host
 * runs with MSR[HV]=0, so the host takes all interrupts on behalf of the
 * guest. PR KVM runs with LPCR[AIL]=0 which causes interrupts to always be
 * delivered to the real-mode entry point, therefore such interrupts only test
 * KVM in their real mode handlers, and only when PR KVM is possible.
 *
 * Interrupts that are taken in MSR[HV]=0 and escalate to MSR[HV]=1 are always
 * delivered in real-mode when the MMU is in hash mode because the MMU
 * registers are not set appropriately to translate host addresses. In nested
 * radix mode these can be delivered in virt-mode as the host translations are
 * used implicitly (see: effective LPID, effective PID).
 */

/*
 * If an interrupt is taken while a guest is running, it is immediately routed
 * to KVM to handle. If both HV and PR KVM arepossible, KVM interrupts go first
 * to kvmppc_interrupt_hv, which handles the PR guest case.
 */
#define kvmppc_interrupt kvmppc_interrupt_hv
#else
#define kvmppc_interrupt kvmppc_interrupt_pr
#endif

.macro KVMTEST name
        lbz     r10,HSTATE_IN_GUEST(r13)
        cmpwi   r10,0
        bne     \name\()_kvm
.endm

.macro GEN_KVM name
        .balign IFETCH_ALIGN_BYTES
\name\()_kvm:

        .if IKVM_SKIP
        cmpwi   r10,KVM_GUEST_MODE_SKIP
        beq     89f
        .else
BEGIN_FTR_SECTION
        ld      r10,IAREA+EX_CFAR(r13)
        std     r10,HSTATE_CFAR(r13)
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
        .endif

        ld      r10,IAREA+EX_CTR(r13)
        mtctr   r10
BEGIN_FTR_SECTION
        ld      r10,IAREA+EX_PPR(r13)
        std     r10,HSTATE_PPR(r13)
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
        ld      r11,IAREA+EX_R11(r13)
        ld      r12,IAREA+EX_R12(r13)
        std     r12,HSTATE_SCRATCH0(r13)
        sldi    r12,r9,32
        ld      r9,IAREA+EX_R9(r13)
        ld      r10,IAREA+EX_R10(r13)
        /* HSRR variants have the 0x2 bit added to their trap number */
        .if IHSRR_IF_HVMODE
        BEGIN_FTR_SECTION
        ori     r12,r12,(IVEC + 0x2)
        FTR_SECTION_ELSE
        ori     r12,r12,(IVEC)
        ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
        .elseif IHSRR
        ori     r12,r12,(IVEC+ 0x2)
        .else
        ori     r12,r12,(IVEC)
        .endif
        b       kvmppc_interrupt

        .if IKVM_SKIP
89:     mtocrf  0x80,r9
        ld      r10,IAREA+EX_CTR(r13)
        mtctr   r10
        ld      r9,IAREA+EX_R9(r13)
        ld      r10,IAREA+EX_R10(r13)
        ld      r11,IAREA+EX_R11(r13)
        ld      r12,IAREA+EX_R12(r13)
        .if IHSRR_IF_HVMODE
        BEGIN_FTR_SECTION
        b       kvmppc_skip_Hinterrupt
        FTR_SECTION_ELSE
        b       kvmppc_skip_interrupt
        ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
        .elseif IHSRR
        b       kvmppc_skip_Hinterrupt
        .else
        b       kvmppc_skip_interrupt
        .endif
        .endif
.endm

#else
.macro KVMTEST name
.endm
.macro GEN_KVM name
.endm
#endif

/*
 * This is the BOOK3S interrupt entry code macro.
 *
 * This can result in one of several things happening:
 * - Branch to the _common handler, relocated, in virtual mode.
 *   These are normal interrupts (synchronous and asynchronous) handled by
 *   the kernel.
 * - Branch to KVM, relocated but real mode interrupts remain in real mode.
 *   These occur when HSTATE_IN_GUEST is set. The interrupt may be caused by
 *   / intended for host or guest kernel, but KVM must always be involved
 *   because the machine state is set for guest execution.
 * - Branch to the masked handler, unrelocated.
 *   These occur when maskable asynchronous interrupts are taken with the
 *   irq_soft_mask set.
 * - Branch to an "early" handler in real mode but relocated.
 *   This is done if early=1. MCE and HMI use these to handle errors in real
 *   mode.
 * - Fall through and continue executing in real, unrelocated mode.
 *   This is done if early=2.
 */

.macro GEN_BRANCH_TO_COMMON name, virt
        .if IREALMODE_COMMON
        LOAD_HANDLER(r10, \name\()_common)
        mtctr   r10
        bctr
        .else
        .if \virt
#ifndef CONFIG_RELOCATABLE
        b       \name\()_common_virt
#else
        LOAD_HANDLER(r10, \name\()_common_virt)
        mtctr   r10
        bctr
#endif
        .else
        LOAD_HANDLER(r10, \name\()_common_real)
        mtctr   r10
        bctr
        .endif
        .endif
.endm

.macro GEN_INT_ENTRY name, virt, ool=0
        SET_SCRATCH0(r13)                       /* save r13 */
        GET_PACA(r13)
        std     r9,IAREA+EX_R9(r13)             /* save r9 */
BEGIN_FTR_SECTION
        mfspr   r9,SPRN_PPR
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
        HMT_MEDIUM
        std     r10,IAREA+EX_R10(r13)           /* save r10 - r12 */
BEGIN_FTR_SECTION
        mfspr   r10,SPRN_CFAR
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
        .if \ool
        .if !\virt
        b       tramp_real_\name
        .pushsection .text
        TRAMP_REAL_BEGIN(tramp_real_\name)
        .else
        b       tramp_virt_\name
        .pushsection .text
        TRAMP_VIRT_BEGIN(tramp_virt_\name)
        .endif
        .endif

BEGIN_FTR_SECTION
        std     r9,IAREA+EX_PPR(r13)
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
BEGIN_FTR_SECTION
        std     r10,IAREA+EX_CFAR(r13)
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
        INTERRUPT_TO_KERNEL
        mfctr   r10
        std     r10,IAREA+EX_CTR(r13)
        mfcr    r9
        std     r11,IAREA+EX_R11(r13)
        std     r12,IAREA+EX_R12(r13)

        /*
         * DAR/DSISR, SCRATCH0 must be read before setting MSR[RI],
         * because a d-side MCE will clobber those registers so is
         * not recoverable if they are live.
         */
        GET_SCRATCH0(r10)
        std     r10,IAREA+EX_R13(r13)
        .if IDAR && !IISIDE
        .if IHSRR
        mfspr   r10,SPRN_HDAR
        .else
        mfspr   r10,SPRN_DAR
        .endif
        std     r10,IAREA+EX_DAR(r13)
        .endif
        .if IDSISR && !IISIDE
        .if IHSRR
        mfspr   r10,SPRN_HDSISR
        .else
        mfspr   r10,SPRN_DSISR
        .endif
        stw     r10,IAREA+EX_DSISR(r13)
        .endif

        .if IHSRR_IF_HVMODE
        BEGIN_FTR_SECTION
        mfspr   r11,SPRN_HSRR0          /* save HSRR0 */
        mfspr   r12,SPRN_HSRR1          /* and HSRR1 */
        FTR_SECTION_ELSE
        mfspr   r11,SPRN_SRR0           /* save SRR0 */
        mfspr   r12,SPRN_SRR1           /* and SRR1 */
        ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
        .elseif IHSRR
        mfspr   r11,SPRN_HSRR0          /* save HSRR0 */
        mfspr   r12,SPRN_HSRR1          /* and HSRR1 */
        .else
        mfspr   r11,SPRN_SRR0           /* save SRR0 */
        mfspr   r12,SPRN_SRR1           /* and SRR1 */
        .endif

        .if IBRANCH_TO_COMMON
        GEN_BRANCH_TO_COMMON \name \virt
        .endif

        .if \ool
        .popsection
        .endif
.endm

/*
 * __GEN_COMMON_ENTRY is required to receive the branch from interrupt
 * entry, except in the case of the real-mode handlers which require
 * __GEN_REALMODE_COMMON_ENTRY.
 *
 * This switches to virtual mode and sets MSR[RI].
 */
.macro __GEN_COMMON_ENTRY name
DEFINE_FIXED_SYMBOL(\name\()_common_real)
\name\()_common_real:
        .if IKVM_REAL
                KVMTEST \name
        .endif

        ld      r10,PACAKMSR(r13)       /* get MSR value for kernel */
        /* MSR[RI] is clear iff using SRR regs */
        .if IHSRR == EXC_HV_OR_STD
        BEGIN_FTR_SECTION
        xori    r10,r10,MSR_RI
        END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE)
        .elseif ! IHSRR
        xori    r10,r10,MSR_RI
        .endif
        mtmsrd  r10

        .if IVIRT
        .if IKVM_VIRT
        b       1f /* skip the virt test coming from real */
        .endif

        .balign IFETCH_ALIGN_BYTES
DEFINE_FIXED_SYMBOL(\name\()_common_virt)
\name\()_common_virt:
        .if IKVM_VIRT
                KVMTEST \name
1:
        .endif
        .endif /* IVIRT */
.endm

/*
 * Don't switch to virt mode. Used for early MCE and HMI handlers that
 * want to run in real mode.
 */
.macro __GEN_REALMODE_COMMON_ENTRY name
DEFINE_FIXED_SYMBOL(\name\()_common_real)
\name\()_common_real:
        .if IKVM_REAL
                KVMTEST \name
        .endif
.endm

.macro __GEN_COMMON_BODY name
        .if IMASK
                .if ! ISTACK
                .error "No support for masked interrupt to use custom stack"
                .endif

                /* If coming from user, skip soft-mask tests. */
                andi.   r10,r12,MSR_PR
                bne     2f

                /* Kernel code running below __end_interrupts is implicitly
                 * soft-masked */
                LOAD_HANDLER(r10, __end_interrupts)
                cmpld   r11,r10
                li      r10,IMASK
                blt-    1f

                /* Test the soft mask state against our interrupt's bit */
                lbz     r10,PACAIRQSOFTMASK(r13)
1:              andi.   r10,r10,IMASK
                /* Associate vector numbers with bits in paca->irq_happened */
                .if IVEC == 0x500 || IVEC == 0xea0
                li      r10,PACA_IRQ_EE
                .elseif IVEC == 0x900
                li      r10,PACA_IRQ_DEC
                .elseif IVEC == 0xa00 || IVEC == 0xe80
                li      r10,PACA_IRQ_DBELL
                .elseif IVEC == 0xe60
                li      r10,PACA_IRQ_HMI
                .elseif IVEC == 0xf00
                li      r10,PACA_IRQ_PMI
                .else
                .abort "Bad maskable vector"
                .endif

                .if IHSRR_IF_HVMODE
                BEGIN_FTR_SECTION
                bne     masked_Hinterrupt
                FTR_SECTION_ELSE
                bne     masked_interrupt
                ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
                .elseif IHSRR
                bne     masked_Hinterrupt
                .else
                bne     masked_interrupt
                .endif
        .endif

        .if ISTACK
        andi.   r10,r12,MSR_PR          /* See if coming from user      */
2:      mr      r10,r1                  /* Save r1                      */
        subi    r1,r1,INT_FRAME_SIZE    /* alloc frame on kernel stack  */
        beq-    100f
        ld      r1,PACAKSAVE(r13)       /* kernel stack to use          */
100:    tdgei   r1,-INT_FRAME_SIZE      /* trap if r1 is in userspace   */
        EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,0
        .endif

        std     r9,_CCR(r1)             /* save CR in stackframe        */
        std     r11,_NIP(r1)            /* save SRR0 in stackframe      */
        std     r12,_MSR(r1)            /* save SRR1 in stackframe      */
        std     r10,0(r1)               /* make stack chain pointer     */
        std     r0,GPR0(r1)             /* save r0 in stackframe        */
        std     r10,GPR1(r1)            /* save r1 in stackframe        */

        .if ISET_RI
        li      r10,MSR_RI
        mtmsrd  r10,1                   /* Set MSR_RI */
        .endif

        .if ISTACK
        .if IKUAP
        kuap_save_amr_and_lock r9, r10, cr1, cr0
        .endif
        beq     101f                    /* if from kernel mode          */
        ACCOUNT_CPU_USER_ENTRY(r13, r9, r10)
BEGIN_FTR_SECTION
        ld      r9,IAREA+EX_PPR(r13)    /* Read PPR from paca           */
        std     r9,_PPR(r1)
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
101:
        .else
        .if IKUAP
        kuap_save_amr_and_lock r9, r10, cr1
        .endif
        .endif

        /* Save original regs values from save area to stack frame. */
        ld      r9,IAREA+EX_R9(r13)     /* move r9, r10 to stackframe   */
        ld      r10,IAREA+EX_R10(r13)
        std     r9,GPR9(r1)
        std     r10,GPR10(r1)
        ld      r9,IAREA+EX_R11(r13)    /* move r11 - r13 to stackframe */
        ld      r10,IAREA+EX_R12(r13)
        ld      r11,IAREA+EX_R13(r13)
        std     r9,GPR11(r1)
        std     r10,GPR12(r1)
        std     r11,GPR13(r1)

        SAVE_NVGPRS(r1)

        .if IDAR
        .if IISIDE
        ld      r10,_NIP(r1)
        .else
        ld      r10,IAREA+EX_DAR(r13)
        .endif
        std     r10,_DAR(r1)
        .endif

        .if IDSISR
        .if IISIDE
        ld      r10,_MSR(r1)
        lis     r11,DSISR_SRR1_MATCH_64S@h
        and     r10,r10,r11
        .else
        lwz     r10,IAREA+EX_DSISR(r13)
        .endif
        std     r10,_DSISR(r1)
        .endif

BEGIN_FTR_SECTION
        ld      r10,IAREA+EX_CFAR(r13)
        std     r10,ORIG_GPR3(r1)
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
        ld      r10,IAREA+EX_CTR(r13)
        std     r10,_CTR(r1)
        std     r2,GPR2(r1)             /* save r2 in stackframe        */
        SAVE_4GPRS(3, r1)               /* save r3 - r6 in stackframe   */
        SAVE_2GPRS(7, r1)               /* save r7, r8 in stackframe    */
        mflr    r9                      /* Get LR, later save to stack  */
        ld      r2,PACATOC(r13)         /* get kernel TOC into r2       */
        std     r9,_LINK(r1)
        lbz     r10,PACAIRQSOFTMASK(r13)
        mfspr   r11,SPRN_XER            /* save XER in stackframe       */
        std     r10,SOFTE(r1)
        std     r11,_XER(r1)
        li      r9,IVEC
        std     r9,_TRAP(r1)            /* set trap number              */
        li      r10,0
        ld      r11,exception_marker@toc(r2)
        std     r10,RESULT(r1)          /* clear regs->result           */
        std     r11,STACK_FRAME_OVERHEAD-16(r1) /* mark the frame       */

        .if ISTACK
        ACCOUNT_STOLEN_TIME
        .endif

        .if IRECONCILE
        RECONCILE_IRQ_STATE(r10, r11)
        .endif
.endm

/*
 * On entry r13 points to the paca, r9-r13 are saved in the paca,
 * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
 * SRR1, and relocation is on.
 *
 * If stack=0, then the stack is already set in r1, and r1 is saved in r10.
 * PPR save and CPU accounting is not done for the !stack case (XXX why not?)
 */
.macro GEN_COMMON name
        __GEN_COMMON_ENTRY \name
        __GEN_COMMON_BODY \name
.endm

/*
 * Restore all registers including H/SRR0/1 saved in a stack frame of a
 * standard exception.
 */
.macro EXCEPTION_RESTORE_REGS hsrr=0
        /* Move original SRR0 and SRR1 into the respective regs */
        ld      r9,_MSR(r1)
        .if \hsrr
        mtspr   SPRN_HSRR1,r9
        .else
        mtspr   SPRN_SRR1,r9
        .endif
        ld      r9,_NIP(r1)
        .if \hsrr
        mtspr   SPRN_HSRR0,r9
        .else
        mtspr   SPRN_SRR0,r9
        .endif
        ld      r9,_CTR(r1)
        mtctr   r9
        ld      r9,_XER(r1)
        mtxer   r9
        ld      r9,_LINK(r1)
        mtlr    r9
        ld      r9,_CCR(r1)
        mtcr    r9
        REST_8GPRS(2, r1)
        REST_4GPRS(10, r1)
        REST_GPR(0, r1)
        /* restore original r1. */
        ld      r1,GPR1(r1)
.endm

#define RUNLATCH_ON                             \
BEGIN_FTR_SECTION                               \
        ld      r3, PACA_THREAD_INFO(r13);      \
        ld      r4,TI_LOCAL_FLAGS(r3);          \
        andi.   r0,r4,_TLF_RUNLATCH;            \
        beql    ppc64_runlatch_on_trampoline;   \
END_FTR_SECTION_IFSET(CPU_FTR_CTRL)

/*
 * When the idle code in power4_idle puts the CPU into NAP mode,
 * it has to do so in a loop, and relies on the external interrupt
 * and decrementer interrupt entry code to get it out of the loop.
 * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
 * to signal that it is in the loop and needs help to get out.
 */
#ifdef CONFIG_PPC_970_NAP
#define FINISH_NAP                              \
BEGIN_FTR_SECTION                               \
        ld      r11, PACA_THREAD_INFO(r13);     \
        ld      r9,TI_LOCAL_FLAGS(r11);         \
        andi.   r10,r9,_TLF_NAPPING;            \
        bnel    power4_fixup_nap;               \
END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
#else
#define FINISH_NAP
#endif

/*
 * There are a few constraints to be concerned with.
 * - Real mode exceptions code/data must be located at their physical location.
 * - Virtual mode exceptions must be mapped at their 0xc000... location.
 * - Fixed location code must not call directly beyond the __end_interrupts
 *   area when built with CONFIG_RELOCATABLE. LOAD_HANDLER / bctr sequence
 *   must be used.
 * - LOAD_HANDLER targets must be within first 64K of physical 0 /
 *   virtual 0xc00...
 * - Conditional branch targets must be within +/-32K of caller.
 *
 * "Virtual exceptions" run with relocation on (MSR_IR=1, MSR_DR=1), and
 * therefore don't have to run in physically located code or rfid to
 * virtual mode kernel code. However on relocatable kernels they do have
 * to branch to KERNELBASE offset because the rest of the kernel (outside
 * the exception vectors) may be located elsewhere.
 *
 * Virtual exceptions correspond with physical, except their entry points
 * are offset by 0xc000000000000000 and also tend to get an added 0x4000
 * offset applied. Virtual exceptions are enabled with the Alternate
 * Interrupt Location (AIL) bit set in the LPCR. However this does not
 * guarantee they will be delivered virtually. Some conditions (see the ISA)
 * cause exceptions to be delivered in real mode.
 *
 * The scv instructions are a special case. They get a 0x3000 offset applied.
 * scv exceptions have unique reentrancy properties, see below.
 *
 * It's impossible to receive interrupts below 0x300 via AIL.
 *
 * KVM: None of the virtual exceptions are from the guest. Anything that
 * escalated to HV=1 from HV=0 is delivered via real mode handlers.
 *
 *
 * We layout physical memory as follows:
 * 0x0000 - 0x00ff : Secondary processor spin code
 * 0x0100 - 0x18ff : Real mode pSeries interrupt vectors
 * 0x1900 - 0x2fff : Real mode trampolines
 * 0x3000 - 0x58ff : Relon (IR=1,DR=1) mode pSeries interrupt vectors
 * 0x5900 - 0x6fff : Relon mode trampolines
 * 0x7000 - 0x7fff : FWNMI data area
 * 0x8000 -   .... : Common interrupt handlers, remaining early
 *                   setup code, rest of kernel.
 *
 * We could reclaim 0x4000-0x42ff for real mode trampolines if the space
 * is necessary. Until then it's more consistent to explicitly put VIRT_NONE
 * vectors there.
 */
OPEN_FIXED_SECTION(real_vectors,        0x0100, 0x1900)
OPEN_FIXED_SECTION(real_trampolines,    0x1900, 0x3000)
OPEN_FIXED_SECTION(virt_vectors,        0x3000, 0x5900)
OPEN_FIXED_SECTION(virt_trampolines,    0x5900, 0x7000)

#ifdef CONFIG_PPC_POWERNV
        .globl start_real_trampolines
        .globl end_real_trampolines
        .globl start_virt_trampolines
        .globl end_virt_trampolines
#endif

#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
/*
 * Data area reserved for FWNMI option.
 * This address (0x7000) is fixed by the RPA.
 * pseries and powernv need to keep the whole page from
 * 0x7000 to 0x8000 free for use by the firmware
 */
ZERO_FIXED_SECTION(fwnmi_page,          0x7000, 0x8000)
OPEN_TEXT_SECTION(0x8000)
#else
OPEN_TEXT_SECTION(0x7000)
#endif

USE_FIXED_SECTION(real_vectors)

/*
 * This is the start of the interrupt handlers for pSeries
 * This code runs with relocation off.
 * Code from here to __end_interrupts gets copied down to real
 * address 0x100 when we are running a relocatable kernel.
 * Therefore any relative branches in this section must only
 * branch to labels in this section.
 */
        .globl __start_interrupts
__start_interrupts:

/**
 * Interrupt 0x3000 - System Call Vectored Interrupt (syscall).
 * This is a synchronous interrupt invoked with the "scv" instruction. The
 * system call does not alter the HV bit, so it is directed to the OS.
 *
 * Handling:
 * scv instructions enter the kernel without changing EE, RI, ME, or HV.
 * In particular, this means we can take a maskable interrupt at any point
 * in the scv handler, which is unlike any other interrupt. This is solved
 * by treating the instruction addresses below __end_interrupts as being
 * soft-masked.
 *
 * AIL-0 mode scv exceptions go to 0x17000-0x17fff, but we set AIL-3 and
 * ensure scv is never executed with relocation off, which means AIL-0
 * should never happen.
 *
 * Before leaving the below __end_interrupts text, at least of the following
 * must be true:
 * - MSR[PR]=1 (i.e., return to userspace)
 * - MSR_EE|MSR_RI is set (no reentrant exceptions)
 * - Standard kernel environment is set up (stack, paca, etc)
 *
 * Call convention:
 *
 * syscall register convention is in Documentation/powerpc/syscall64-abi.rst
 */
EXC_VIRT_BEGIN(system_call_vectored, 0x3000, 0x1000)
        /* SCV 0 */
        mr      r9,r13
        GET_PACA(r13)
        mflr    r11
        mfctr   r12
        li      r10,IRQS_ALL_DISABLED
        stb     r10,PACAIRQSOFTMASK(r13)
#ifdef CONFIG_RELOCATABLE
        b       system_call_vectored_tramp
#else
        b       system_call_vectored_common
#endif
        nop

        /* SCV 1 - 127 */
        .rept   127
        mr      r9,r13
        GET_PACA(r13)
        mflr    r11
        mfctr   r12
        li      r10,IRQS_ALL_DISABLED
        stb     r10,PACAIRQSOFTMASK(r13)
        li      r0,-1 /* cause failure */
#ifdef CONFIG_RELOCATABLE
        b       system_call_vectored_sigill_tramp
#else
        b       system_call_vectored_sigill
#endif
        .endr
EXC_VIRT_END(system_call_vectored, 0x3000, 0x1000)

#ifdef CONFIG_RELOCATABLE
TRAMP_VIRT_BEGIN(system_call_vectored_tramp)
        __LOAD_HANDLER(r10, system_call_vectored_common)
        mtctr   r10
        bctr

TRAMP_VIRT_BEGIN(system_call_vectored_sigill_tramp)
        __LOAD_HANDLER(r10, system_call_vectored_sigill)
        mtctr   r10
        bctr
#endif


/* No virt vectors corresponding with 0x0..0x100 */
EXC_VIRT_NONE(0x4000, 0x100)


/**
 * Interrupt 0x100 - System Reset Interrupt (SRESET aka NMI).
 * This is a non-maskable, asynchronous interrupt always taken in real-mode.
 * It is caused by:
 * - Wake from power-saving state, on powernv.
 * - An NMI from another CPU, triggered by firmware or hypercall.
 * - As crash/debug signal injected from BMC, firmware or hypervisor.
 *
 * Handling:
 * Power-save wakeup is the only performance critical path, so this is
 * determined quickly as possible first. In this case volatile registers
 * can be discarded and SPRs like CFAR don't need to be read.
 *
 * If not a powersave wakeup, then it's run as a regular interrupt, however
 * it uses its own stack and PACA save area to preserve the regular kernel
 * environment for debugging.
 *
 * This interrupt is not maskable, so triggering it when MSR[RI] is clear,
 * or SCRATCH0 is in use, etc. may cause a crash. It's also not entirely
 * correct to switch to virtual mode to run the regular interrupt handler
 * because it might be interrupted when the MMU is in a bad state (e.g., SLB
 * is clear).
 *
 * FWNMI:
 * PAPR specifies a "fwnmi" facility which sends the sreset to a different
 * entry point with a different register set up. Some hypervisors will
 * send the sreset to 0x100 in the guest if it is not fwnmi capable.
 *
 * KVM:
 * Unlike most SRR interrupts, this may be taken by the host while executing
 * in a guest, so a KVM test is required. KVM will pull the CPU out of guest
 * mode and then raise the sreset.
 */
INT_DEFINE_BEGIN(system_reset)
        IVEC=0x100
        IAREA=PACA_EXNMI
        IVIRT=0 /* no virt entry point */
        /*
         * MSR_RI is not enabled, because PACA_EXNMI and nmi stack is
         * being used, so a nested NMI exception would corrupt it.
         */
        ISET_RI=0
        ISTACK=0
        IRECONCILE=0
        IKVM_REAL=1
INT_DEFINE_END(system_reset)

EXC_REAL_BEGIN(system_reset, 0x100, 0x100)
#ifdef CONFIG_PPC_P7_NAP
        /*
         * If running native on arch 2.06 or later, check if we are waking up
         * from nap/sleep/winkle, and branch to idle handler. This tests SRR1
         * bits 46:47. A non-0 value indicates that we are coming from a power
         * saving state. The idle wakeup handler initially runs in real mode,
         * but we branch to the 0xc000... address so we can turn on relocation
         * with mtmsrd later, after SPRs are restored.
         *
         * Careful to minimise cost for the fast path (idle wakeup) while
         * also avoiding clobbering CFAR for the debug path (non-idle).
         *
         * For the idle wake case volatile registers can be clobbered, which
         * is why we use those initially. If it turns out to not be an idle
         * wake, carefully put everything back the way it was, so we can use
         * common exception macros to handle it.
         */
BEGIN_FTR_SECTION
        SET_SCRATCH0(r13)
        GET_PACA(r13)
        std     r3,PACA_EXNMI+0*8(r13)
        std     r4,PACA_EXNMI+1*8(r13)
        std     r5,PACA_EXNMI+2*8(r13)
        mfspr   r3,SPRN_SRR1
        mfocrf  r4,0x80
        rlwinm. r5,r3,47-31,30,31
        bne+    system_reset_idle_wake
        /* Not powersave wakeup. Restore regs for regular interrupt handler. */
        mtocrf  0x80,r4
        ld      r3,PACA_EXNMI+0*8(r13)
        ld      r4,PACA_EXNMI+1*8(r13)
        ld      r5,PACA_EXNMI+2*8(r13)
        GET_SCRATCH0(r13)
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
#endif

        GEN_INT_ENTRY system_reset, virt=0
        /*
         * In theory, we should not enable relocation here if it was disabled
         * in SRR1, because the MMU may not be configured to support it (e.g.,
         * SLB may have been cleared). In practice, there should only be a few
         * small windows where that's the case, and sreset is considered to
         * be dangerous anyway.
         */
EXC_REAL_END(system_reset, 0x100, 0x100)
EXC_VIRT_NONE(0x4100, 0x100)

#ifdef CONFIG_PPC_P7_NAP
TRAMP_REAL_BEGIN(system_reset_idle_wake)
        /* We are waking up from idle, so may clobber any volatile register */
        cmpwi   cr1,r5,2
        bltlr   cr1     /* no state loss, return to idle caller with r3=SRR1 */
        BRANCH_TO_C000(r12, DOTSYM(idle_return_gpr_loss))
#endif

#ifdef CONFIG_PPC_PSERIES
/*
 * Vectors for the FWNMI option.  Share common code.
 */
TRAMP_REAL_BEGIN(system_reset_fwnmi)
        /* XXX: fwnmi guest could run a nested/PR guest, so why no test?  */
        __IKVM_REAL(system_reset)=0
        GEN_INT_ENTRY system_reset, virt=0

#endif /* CONFIG_PPC_PSERIES */

EXC_COMMON_BEGIN(system_reset_common)
        __GEN_COMMON_ENTRY system_reset
        /*
         * Increment paca->in_nmi then enable MSR_RI. SLB or MCE will be able
         * to recover, but nested NMI will notice in_nmi and not recover
         * because of the use of the NMI stack. in_nmi reentrancy is tested in
         * system_reset_exception.
         */
        lhz     r10,PACA_IN_NMI(r13)
        addi    r10,r10,1
        sth     r10,PACA_IN_NMI(r13)
        li      r10,MSR_RI
        mtmsrd  r10,1

        mr      r10,r1
        ld      r1,PACA_NMI_EMERG_SP(r13)
        subi    r1,r1,INT_FRAME_SIZE
        __GEN_COMMON_BODY system_reset
        /*
         * Set IRQS_ALL_DISABLED unconditionally so irqs_disabled() does
         * the right thing. We do not want to reconcile because that goes
         * through irq tracing which we don't want in NMI.
         *
         * Save PACAIRQHAPPENED to RESULT (otherwise unused), and set HARD_DIS
         * as we are running with MSR[EE]=0.
         */
        li      r10,IRQS_ALL_DISABLED
        stb     r10,PACAIRQSOFTMASK(r13)
        lbz     r10,PACAIRQHAPPENED(r13)
        std     r10,RESULT(r1)
        ori     r10,r10,PACA_IRQ_HARD_DIS
        stb     r10,PACAIRQHAPPENED(r13)

        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      system_reset_exception

        /* Clear MSR_RI before setting SRR0 and SRR1. */
        li      r9,0
        mtmsrd  r9,1

        /*
         * MSR_RI is clear, now we can decrement paca->in_nmi.
         */
        lhz     r10,PACA_IN_NMI(r13)
        subi    r10,r10,1
        sth     r10,PACA_IN_NMI(r13)

        /*
         * Restore soft mask settings.
         */
        ld      r10,RESULT(r1)
        stb     r10,PACAIRQHAPPENED(r13)
        ld      r10,SOFTE(r1)
        stb     r10,PACAIRQSOFTMASK(r13)

        kuap_restore_amr r9, r10
        EXCEPTION_RESTORE_REGS
        RFI_TO_USER_OR_KERNEL

        GEN_KVM system_reset


/**
 * Interrupt 0x200 - Machine Check Interrupt (MCE).
 * This is a non-maskable interrupt always taken in real-mode. It can be
 * synchronous or asynchronous, caused by hardware or software, and it may be
 * taken in a power-saving state.
 *
 * Handling:
 * Similarly to system reset, this uses its own stack and PACA save area,
 * the difference is re-entrancy is allowed on the machine check stack.
 *
 * machine_check_early is run in real mode, and carefully decodes the
 * machine check and tries to handle it (e.g., flush the SLB if there was an
 * error detected there), determines if it was recoverable and logs the
 * event.
 *
 * This early code does not "reconcile" irq soft-mask state like SRESET or
 * regular interrupts do, so irqs_disabled() among other things may not work
 * properly (irq disable/enable already doesn't work because irq tracing can
 * not work in real mode).
 *
 * Then, depending on the execution context when the interrupt is taken, there
 * are 3 main actions:
 * - Executing in kernel mode. The event is queued with irq_work, which means
 *   it is handled when it is next safe to do so (i.e., the kernel has enabled
 *   interrupts), which could be immediately when the interrupt returns. This
 *   avoids nasty issues like switching to virtual mode when the MMU is in a
 *   bad state, or when executing OPAL code. (SRESET is exposed to such issues,
 *   but it has different priorities). Check to see if the CPU was in power
 *   save, and return via the wake up code if it was.
 *
 * - Executing in user mode. machine_check_exception is run like a normal
 *   interrupt handler, which processes the data generated by the early handler.
 *
 * - Executing in guest mode. The interrupt is run with its KVM test, and
 *   branches to KVM to deal with. KVM may queue the event for the host
 *   to report later.
 *
 * This interrupt is not maskable, so if it triggers when MSR[RI] is clear,
 * or SCRATCH0 is in use, it may cause a crash.
 *
 * KVM:
 * See SRESET.
 */
INT_DEFINE_BEGIN(machine_check_early)
        IVEC=0x200
        IAREA=PACA_EXMC
        IVIRT=0 /* no virt entry point */
        IREALMODE_COMMON=1
        /*
         * MSR_RI is not enabled, because PACA_EXMC is being used, so a
         * nested machine check corrupts it. machine_check_common enables
         * MSR_RI.
         */
        ISET_RI=0
        ISTACK=0
        IDAR=1
        IDSISR=1
        IRECONCILE=0
        IKUAP=0 /* We don't touch AMR here, we never go to virtual mode */
INT_DEFINE_END(machine_check_early)

INT_DEFINE_BEGIN(machine_check)
        IVEC=0x200
        IAREA=PACA_EXMC
        IVIRT=0 /* no virt entry point */
        ISET_RI=0
        IDAR=1
        IDSISR=1
        IKVM_SKIP=1
        IKVM_REAL=1
INT_DEFINE_END(machine_check)

EXC_REAL_BEGIN(machine_check, 0x200, 0x100)
        GEN_INT_ENTRY machine_check_early, virt=0
EXC_REAL_END(machine_check, 0x200, 0x100)
EXC_VIRT_NONE(0x4200, 0x100)

#ifdef CONFIG_PPC_PSERIES
TRAMP_REAL_BEGIN(machine_check_fwnmi)
        /* See comment at machine_check exception, don't turn on RI */
        GEN_INT_ENTRY machine_check_early, virt=0
#endif

#define MACHINE_CHECK_HANDLER_WINDUP                    \
        /* Clear MSR_RI before setting SRR0 and SRR1. */\
        li      r9,0;                                   \
        mtmsrd  r9,1;           /* Clear MSR_RI */      \
        /* Decrement paca->in_mce now RI is clear. */   \
        lhz     r12,PACA_IN_MCE(r13);                   \
        subi    r12,r12,1;                              \
        sth     r12,PACA_IN_MCE(r13);                   \
        EXCEPTION_RESTORE_REGS

EXC_COMMON_BEGIN(machine_check_early_common)
        __GEN_REALMODE_COMMON_ENTRY machine_check_early

        /*
         * Switch to mc_emergency stack and handle re-entrancy (we limit
         * the nested MCE upto level 4 to avoid stack overflow).
         * Save MCE registers srr1, srr0, dar and dsisr and then set ME=1
         *
         * We use paca->in_mce to check whether this is the first entry or
         * nested machine check. We increment paca->in_mce to track nested
         * machine checks.
         *
         * If this is the first entry then set stack pointer to
         * paca->mc_emergency_sp, otherwise r1 is already pointing to
         * stack frame on mc_emergency stack.
         *
         * NOTE: We are here with MSR_ME=0 (off), which means we risk a
         * checkstop if we get another machine check exception before we do
         * rfid with MSR_ME=1.
         *
         * This interrupt can wake directly from idle. If that is the case,
         * the machine check is handled then the idle wakeup code is called
         * to restore state.
         */
        lhz     r10,PACA_IN_MCE(r13)
        cmpwi   r10,0                   /* Are we in nested machine check */
        cmpwi   cr1,r10,MAX_MCE_DEPTH   /* Are we at maximum nesting */
        addi    r10,r10,1               /* increment paca->in_mce */
        sth     r10,PACA_IN_MCE(r13)

        mr      r10,r1                  /* Save r1 */
        bne     1f
        /* First machine check entry */
        ld      r1,PACAMCEMERGSP(r13)   /* Use MC emergency stack */
1:      /* Limit nested MCE to level 4 to avoid stack overflow */
        bgt     cr1,unrecoverable_mce   /* Check if we hit limit of 4 */
        subi    r1,r1,INT_FRAME_SIZE    /* alloc stack frame */

        __GEN_COMMON_BODY machine_check_early

BEGIN_FTR_SECTION
        bl      enable_machine_check
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
        li      r10,MSR_RI
        mtmsrd  r10,1

        /*
         * Set IRQS_ALL_DISABLED and save PACAIRQHAPPENED (see
         * system_reset_common)
         */
        li      r10,IRQS_ALL_DISABLED
        stb     r10,PACAIRQSOFTMASK(r13)
        lbz     r10,PACAIRQHAPPENED(r13)
        std     r10,RESULT(r1)
        ori     r10,r10,PACA_IRQ_HARD_DIS
        stb     r10,PACAIRQHAPPENED(r13)

        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      machine_check_early
        std     r3,RESULT(r1)   /* Save result */
        ld      r12,_MSR(r1)

        /*
         * Restore soft mask settings.
         */
        ld      r10,RESULT(r1)
        stb     r10,PACAIRQHAPPENED(r13)
        ld      r10,SOFTE(r1)
        stb     r10,PACAIRQSOFTMASK(r13)

#ifdef CONFIG_PPC_P7_NAP
        /*
         * Check if thread was in power saving mode. We come here when any
         * of the following is true:
         * a. thread wasn't in power saving mode
         * b. thread was in power saving mode with no state loss,
         *    supervisor state loss or hypervisor state loss.
         *
         * Go back to nap/sleep/winkle mode again if (b) is true.
         */
BEGIN_FTR_SECTION
        rlwinm. r11,r12,47-31,30,31
        bne     machine_check_idle_common
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
#endif

#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
        /*
         * Check if we are coming from guest. If yes, then run the normal
         * exception handler which will take the
         * machine_check_kvm->kvmppc_interrupt branch to deliver the MC event
         * to guest.
         */
        lbz     r11,HSTATE_IN_GUEST(r13)
        cmpwi   r11,0                   /* Check if coming from guest */
        bne     mce_deliver             /* continue if we are. */
#endif

        /*
         * Check if we are coming from userspace. If yes, then run the normal
         * exception handler which will deliver the MC event to this kernel.
         */
        andi.   r11,r12,MSR_PR          /* See if coming from user. */
        bne     mce_deliver             /* continue in V mode if we are. */

        /*
         * At this point we are coming from kernel context.
         * Queue up the MCE event and return from the interrupt.
         * But before that, check if this is an un-recoverable exception.
         * If yes, then stay on emergency stack and panic.
         */
        andi.   r11,r12,MSR_RI
        beq     unrecoverable_mce

        /*
         * Check if we have successfully handled/recovered from error, if not
         * then stay on emergency stack and panic.
         */
        ld      r3,RESULT(r1)   /* Load result */
        cmpdi   r3,0            /* see if we handled MCE successfully */
        beq     unrecoverable_mce /* if !handled then panic */

        /*
         * Return from MC interrupt.
         * Queue up the MCE event so that we can log it later, while
         * returning from kernel or opal call.
         */
        bl      machine_check_queue_event
        MACHINE_CHECK_HANDLER_WINDUP
        RFI_TO_KERNEL

mce_deliver:
        /*
         * This is a host user or guest MCE. Restore all registers, then
         * run the "late" handler. For host user, this will run the
         * machine_check_exception handler in virtual mode like a normal
         * interrupt handler. For guest, this will trigger the KVM test
         * and branch to the KVM interrupt similarly to other interrupts.
         */
BEGIN_FTR_SECTION
        ld      r10,ORIG_GPR3(r1)
        mtspr   SPRN_CFAR,r10
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
        MACHINE_CHECK_HANDLER_WINDUP
        GEN_INT_ENTRY machine_check, virt=0

EXC_COMMON_BEGIN(machine_check_common)
        /*
         * Machine check is different because we use a different
         * save area: PACA_EXMC instead of PACA_EXGEN.
         */
        GEN_COMMON machine_check

        FINISH_NAP
        /* Enable MSR_RI when finished with PACA_EXMC */
        li      r10,MSR_RI
        mtmsrd  r10,1
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      machine_check_exception
        b       interrupt_return

        GEN_KVM machine_check


#ifdef CONFIG_PPC_P7_NAP
/*
 * This is an idle wakeup. Low level machine check has already been
 * done. Queue the event then call the idle code to do the wake up.
 */
EXC_COMMON_BEGIN(machine_check_idle_common)
        bl      machine_check_queue_event

        /*
         * GPR-loss wakeups are relatively straightforward, because the
         * idle sleep code has saved all non-volatile registers on its
         * own stack, and r1 in PACAR1.
         *
         * For no-loss wakeups the r1 and lr registers used by the
         * early machine check handler have to be restored first. r2 is
         * the kernel TOC, so no need to restore it.
         *
         * Then decrement MCE nesting after finishing with the stack.
         */
        ld      r3,_MSR(r1)
        ld      r4,_LINK(r1)
        ld      r1,GPR1(r1)

        lhz     r11,PACA_IN_MCE(r13)
        subi    r11,r11,1
        sth     r11,PACA_IN_MCE(r13)

        mtlr    r4
        rlwinm  r10,r3,47-31,30,31
        cmpwi   cr1,r10,2
        bltlr   cr1     /* no state loss, return to idle caller with r3=SRR1 */
        b       idle_return_gpr_loss
#endif

EXC_COMMON_BEGIN(unrecoverable_mce)
        /*
         * We are going down. But there are chances that we might get hit by
         * another MCE during panic path and we may run into unstable state
         * with no way out. Hence, turn ME bit off while going down, so that
         * when another MCE is hit during panic path, system will checkstop
         * and hypervisor will get restarted cleanly by SP.
         */
BEGIN_FTR_SECTION
        li      r10,0 /* clear MSR_RI */
        mtmsrd  r10,1
        bl      disable_machine_check
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
        ld      r10,PACAKMSR(r13)
        li      r3,MSR_ME
        andc    r10,r10,r3
        mtmsrd  r10

        lhz     r12,PACA_IN_MCE(r13)
        subi    r12,r12,1
        sth     r12,PACA_IN_MCE(r13)

        /* Invoke machine_check_exception to print MCE event and panic. */
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      machine_check_exception

        /*
         * We will not reach here. Even if we did, there is no way out.
         * Call unrecoverable_exception and die.
         */
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      unrecoverable_exception
        b       .


/**
 * Interrupt 0x300 - Data Storage Interrupt (DSI).
 * This is a synchronous interrupt generated due to a data access exception,
 * e.g., a load orstore which does not have a valid page table entry with
 * permissions. DAWR matches also fault here, as do RC updates, and minor misc
 * errors e.g., copy/paste, AMO, certain invalid CI accesses, etc.
 *
 * Handling:
 * - Hash MMU
 *   Go to do_hash_page first to see if the HPT can be filled from an entry in
 *   the Linux page table. Hash faults can hit in kernel mode in a fairly
 *   arbitrary state (e.g., interrupts disabled, locks held) when accessing
 *   "non-bolted" regions, e.g., vmalloc space. However these should always be
 *   backed by Linux page tables.
 *
 *   If none is found, do a Linux page fault. Linux page faults can happen in
 *   kernel mode due to user copy operations of course.
 *
 * - Radix MMU
 *   The hardware loads from the Linux page table directly, so a fault goes
 *   immediately to Linux page fault.
 *
 * Conditions like DAWR match are handled on the way in to Linux page fault.
 */
INT_DEFINE_BEGIN(data_access)
        IVEC=0x300
        IDAR=1
        IDSISR=1
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_SKIP=1
        IKVM_REAL=1
#endif
INT_DEFINE_END(data_access)

EXC_REAL_BEGIN(data_access, 0x300, 0x80)
        GEN_INT_ENTRY data_access, virt=0
EXC_REAL_END(data_access, 0x300, 0x80)
EXC_VIRT_BEGIN(data_access, 0x4300, 0x80)
        GEN_INT_ENTRY data_access, virt=1
EXC_VIRT_END(data_access, 0x4300, 0x80)
EXC_COMMON_BEGIN(data_access_common)
        GEN_COMMON data_access
        ld      r4,_DAR(r1)
        ld      r5,_DSISR(r1)
BEGIN_MMU_FTR_SECTION
        ld      r6,_MSR(r1)
        li      r3,0x300
        b       do_hash_page            /* Try to handle as hpte fault */
MMU_FTR_SECTION_ELSE
        b       handle_page_fault
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)

        GEN_KVM data_access


/**
 * Interrupt 0x380 - Data Segment Interrupt (DSLB).
 * This is a synchronous interrupt in response to an MMU fault missing SLB
 * entry for HPT, or an address outside RPT translation range.
 *
 * Handling:
 * - HPT:
 *   This refills the SLB, or reports an access fault similarly to a bad page
 *   fault. When coming from user-mode, the SLB handler may access any kernel
 *   data, though it may itself take a DSLB. When coming from kernel mode,
 *   recursive faults must be avoided so access is restricted to the kernel
 *   image text/data, kernel stack, and any data allocated below
 *   ppc64_bolted_size (first segment). The kernel handler must avoid stomping
 *   on user-handler data structures.
 *
 * A dedicated save area EXSLB is used (XXX: but it actually need not be
 * these days, we could use EXGEN).
 */
INT_DEFINE_BEGIN(data_access_slb)
        IVEC=0x380
        IAREA=PACA_EXSLB
        IRECONCILE=0
        IDAR=1
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_SKIP=1
        IKVM_REAL=1
#endif
INT_DEFINE_END(data_access_slb)

EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)
        GEN_INT_ENTRY data_access_slb, virt=0
EXC_REAL_END(data_access_slb, 0x380, 0x80)
EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
        GEN_INT_ENTRY data_access_slb, virt=1
EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
EXC_COMMON_BEGIN(data_access_slb_common)
        GEN_COMMON data_access_slb
        ld      r4,_DAR(r1)
        addi    r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
        /* HPT case, do SLB fault */
        bl      do_slb_fault
        cmpdi   r3,0
        bne-    1f
        b       fast_interrupt_return
1:      /* Error case */
MMU_FTR_SECTION_ELSE
        /* Radix case, access is outside page table range */
        li      r3,-EFAULT
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
        std     r3,RESULT(r1)
        RECONCILE_IRQ_STATE(r10, r11)
        ld      r4,_DAR(r1)
        ld      r5,RESULT(r1)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      do_bad_slb_fault
        b       interrupt_return

        GEN_KVM data_access_slb


/**
 * Interrupt 0x400 - Instruction Storage Interrupt (ISI).
 * This is a synchronous interrupt in response to an MMU fault due to an
 * instruction fetch.
 *
 * Handling:
 * Similar to DSI, though in response to fetch. The faulting address is found
 * in SRR0 (rather than DAR), and status in SRR1 (rather than DSISR).
 */
INT_DEFINE_BEGIN(instruction_access)
        IVEC=0x400
        IISIDE=1
        IDAR=1
        IDSISR=1
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(instruction_access)

EXC_REAL_BEGIN(instruction_access, 0x400, 0x80)
        GEN_INT_ENTRY instruction_access, virt=0
EXC_REAL_END(instruction_access, 0x400, 0x80)
EXC_VIRT_BEGIN(instruction_access, 0x4400, 0x80)
        GEN_INT_ENTRY instruction_access, virt=1
EXC_VIRT_END(instruction_access, 0x4400, 0x80)
EXC_COMMON_BEGIN(instruction_access_common)
        GEN_COMMON instruction_access
        ld      r4,_DAR(r1)
        ld      r5,_DSISR(r1)
BEGIN_MMU_FTR_SECTION
        ld      r6,_MSR(r1)
        li      r3,0x400
        b       do_hash_page            /* Try to handle as hpte fault */
MMU_FTR_SECTION_ELSE
        b       handle_page_fault
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)

        GEN_KVM instruction_access


/**
 * Interrupt 0x480 - Instruction Segment Interrupt (ISLB).
 * This is a synchronous interrupt in response to an MMU fault due to an
 * instruction fetch.
 *
 * Handling:
 * Similar to DSLB, though in response to fetch. The faulting address is found
 * in SRR0 (rather than DAR).
 */
INT_DEFINE_BEGIN(instruction_access_slb)
        IVEC=0x480
        IAREA=PACA_EXSLB
        IRECONCILE=0
        IISIDE=1
        IDAR=1
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(instruction_access_slb)

EXC_REAL_BEGIN(instruction_access_slb, 0x480, 0x80)
        GEN_INT_ENTRY instruction_access_slb, virt=0
EXC_REAL_END(instruction_access_slb, 0x480, 0x80)
EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
        GEN_INT_ENTRY instruction_access_slb, virt=1
EXC_VIRT_END(instruction_access_slb, 0x4480, 0x80)
EXC_COMMON_BEGIN(instruction_access_slb_common)
        GEN_COMMON instruction_access_slb
        ld      r4,_DAR(r1)
        addi    r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
        /* HPT case, do SLB fault */
        bl      do_slb_fault
        cmpdi   r3,0
        bne-    1f
        b       fast_interrupt_return
1:      /* Error case */
MMU_FTR_SECTION_ELSE
        /* Radix case, access is outside page table range */
        li      r3,-EFAULT
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
        std     r3,RESULT(r1)
        RECONCILE_IRQ_STATE(r10, r11)
        ld      r4,_DAR(r1)
        ld      r5,RESULT(r1)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      do_bad_slb_fault
        b       interrupt_return

        GEN_KVM instruction_access_slb


/**
 * Interrupt 0x500 - External Interrupt.
 * This is an asynchronous maskable interrupt in response to an "external
 * exception" from the interrupt controller or hypervisor (e.g., device
 * interrupt). It is maskable in hardware by clearing MSR[EE], and
 * soft-maskable with IRQS_DISABLED mask (i.e., local_irq_disable()).
 *
 * When running in HV mode, Linux sets up the LPCR[LPES] bit such that
 * interrupts are delivered with HSRR registers, guests use SRRs, which
 * reqiures IHSRR_IF_HVMODE.
 *
 * On bare metal POWER9 and later, Linux sets the LPCR[HVICE] bit such that
 * external interrupts are delivered as Hypervisor Virtualization Interrupts
 * rather than External Interrupts.
 *
 * Handling:
 * This calls into Linux IRQ handler. NVGPRs are not saved to reduce overhead,
 * because registers at the time of the interrupt are not so important as it is
 * asynchronous.
 *
 * If soft masked, the masked handler will note the pending interrupt for
 * replay, and clear MSR[EE] in the interrupted context.
 */
INT_DEFINE_BEGIN(hardware_interrupt)
        IVEC=0x500
        IHSRR_IF_HVMODE=1
        IMASK=IRQS_DISABLED
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(hardware_interrupt)

EXC_REAL_BEGIN(hardware_interrupt, 0x500, 0x100)
        GEN_INT_ENTRY hardware_interrupt, virt=0
EXC_REAL_END(hardware_interrupt, 0x500, 0x100)
EXC_VIRT_BEGIN(hardware_interrupt, 0x4500, 0x100)
        GEN_INT_ENTRY hardware_interrupt, virt=1
EXC_VIRT_END(hardware_interrupt, 0x4500, 0x100)
EXC_COMMON_BEGIN(hardware_interrupt_common)
        GEN_COMMON hardware_interrupt
        FINISH_NAP
        RUNLATCH_ON
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      do_IRQ
        b       interrupt_return

        GEN_KVM hardware_interrupt


/**
 * Interrupt 0x600 - Alignment Interrupt
 * This is a synchronous interrupt in response to data alignment fault.
 */
INT_DEFINE_BEGIN(alignment)
        IVEC=0x600
        IDAR=1
        IDSISR=1
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(alignment)

EXC_REAL_BEGIN(alignment, 0x600, 0x100)
        GEN_INT_ENTRY alignment, virt=0
EXC_REAL_END(alignment, 0x600, 0x100)
EXC_VIRT_BEGIN(alignment, 0x4600, 0x100)
        GEN_INT_ENTRY alignment, virt=1
EXC_VIRT_END(alignment, 0x4600, 0x100)
EXC_COMMON_BEGIN(alignment_common)
        GEN_COMMON alignment
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      alignment_exception
        REST_NVGPRS(r1) /* instruction emulation may change GPRs */
        b       interrupt_return

        GEN_KVM alignment


/**
 * Interrupt 0x700 - Program Interrupt (program check).
 * This is a synchronous interrupt in response to various instruction faults:
 * traps, privilege errors, TM errors, floating point exceptions.
 *
 * Handling:
 * This interrupt may use the "emergency stack" in some cases when being taken
 * from kernel context, which complicates handling.
 */
INT_DEFINE_BEGIN(program_check)
        IVEC=0x700
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(program_check)

EXC_REAL_BEGIN(program_check, 0x700, 0x100)
        GEN_INT_ENTRY program_check, virt=0
EXC_REAL_END(program_check, 0x700, 0x100)
EXC_VIRT_BEGIN(program_check, 0x4700, 0x100)
        GEN_INT_ENTRY program_check, virt=1
EXC_VIRT_END(program_check, 0x4700, 0x100)
EXC_COMMON_BEGIN(program_check_common)
        __GEN_COMMON_ENTRY program_check

        /*
         * It's possible to receive a TM Bad Thing type program check with
         * userspace register values (in particular r1), but with SRR1 reporting
         * that we came from the kernel. Normally that would confuse the bad
         * stack logic, and we would report a bad kernel stack pointer. Instead
         * we switch to the emergency stack if we're taking a TM Bad Thing from
         * the kernel.
         */

        andi.   r10,r12,MSR_PR
        bne     2f                      /* If userspace, go normal path */

        andis.  r10,r12,(SRR1_PROGTM)@h
        bne     1f                      /* If TM, emergency             */

        cmpdi   r1,-INT_FRAME_SIZE      /* check if r1 is in userspace  */
        blt     2f                      /* normal path if not           */

        /* Use the emergency stack                                      */
1:      andi.   r10,r12,MSR_PR          /* Set CR0 correctly for label  */
                                        /* 3 in EXCEPTION_PROLOG_COMMON */
        mr      r10,r1                  /* Save r1                      */
        ld      r1,PACAEMERGSP(r13)     /* Use emergency stack          */
        subi    r1,r1,INT_FRAME_SIZE    /* alloc stack frame            */
        __ISTACK(program_check)=0
        __GEN_COMMON_BODY program_check
        b 3f
2:
        __ISTACK(program_check)=1
        __GEN_COMMON_BODY program_check
3:
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      program_check_exception
        REST_NVGPRS(r1) /* instruction emulation may change GPRs */
        b       interrupt_return

        GEN_KVM program_check


/*
 * Interrupt 0x800 - Floating-Point Unavailable Interrupt.
 * This is a synchronous interrupt in response to executing an fp instruction
 * with MSR[FP]=0.
 *
 * Handling:
 * This will load FP registers and enable the FP bit if coming from userspace,
 * otherwise report a bad kernel use of FP.
 */
INT_DEFINE_BEGIN(fp_unavailable)
        IVEC=0x800
        IRECONCILE=0
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(fp_unavailable)

EXC_REAL_BEGIN(fp_unavailable, 0x800, 0x100)
        GEN_INT_ENTRY fp_unavailable, virt=0
EXC_REAL_END(fp_unavailable, 0x800, 0x100)
EXC_VIRT_BEGIN(fp_unavailable, 0x4800, 0x100)
        GEN_INT_ENTRY fp_unavailable, virt=1
EXC_VIRT_END(fp_unavailable, 0x4800, 0x100)
EXC_COMMON_BEGIN(fp_unavailable_common)
        GEN_COMMON fp_unavailable
        bne     1f                      /* if from user, just load it up */
        RECONCILE_IRQ_STATE(r10, r11)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      kernel_fp_unavailable_exception
0:      trap
        EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
1:
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
BEGIN_FTR_SECTION
        /* Test if 2 TM state bits are zero.  If non-zero (ie. userspace was in
         * transaction), go do TM stuff
         */
        rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
        bne-    2f
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
        bl      load_up_fpu
        b       fast_interrupt_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2:      /* User process was in a transaction */
        RECONCILE_IRQ_STATE(r10, r11)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      fp_unavailable_tm
        b       interrupt_return
#endif

        GEN_KVM fp_unavailable


/**
 * Interrupt 0x900 - Decrementer Interrupt.
 * This is an asynchronous interrupt in response to a decrementer exception
 * (e.g., DEC has wrapped below zero). It is maskable in hardware by clearing
 * MSR[EE], and soft-maskable with IRQS_DISABLED mask (i.e.,
 * local_irq_disable()).
 *
 * Handling:
 * This calls into Linux timer handler. NVGPRs are not saved (see 0x500).
 *
 * If soft masked, the masked handler will note the pending interrupt for
 * replay, and bump the decrementer to a high value, leaving MSR[EE] enabled
 * in the interrupted context.
 * If PPC_WATCHDOG is configured, the soft masked handler will actually set
 * things back up to run soft_nmi_interrupt as a regular interrupt handler
 * on the emergency stack.
 */
INT_DEFINE_BEGIN(decrementer)
        IVEC=0x900
        IMASK=IRQS_DISABLED
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(decrementer)

EXC_REAL_BEGIN(decrementer, 0x900, 0x80)
        GEN_INT_ENTRY decrementer, virt=0
EXC_REAL_END(decrementer, 0x900, 0x80)
EXC_VIRT_BEGIN(decrementer, 0x4900, 0x80)
        GEN_INT_ENTRY decrementer, virt=1
EXC_VIRT_END(decrementer, 0x4900, 0x80)
EXC_COMMON_BEGIN(decrementer_common)
        GEN_COMMON decrementer
        FINISH_NAP
        RUNLATCH_ON
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      timer_interrupt
        b       interrupt_return

        GEN_KVM decrementer


/**
 * Interrupt 0x980 - Hypervisor Decrementer Interrupt.
 * This is an asynchronous interrupt, similar to 0x900 but for the HDEC
 * register.
 *
 * Handling:
 * Linux does not use this outside KVM where it's used to keep a host timer
 * while the guest is given control of DEC. It should normally be caught by
 * the KVM test and routed there.
 */
INT_DEFINE_BEGIN(hdecrementer)
        IVEC=0x980
        IHSRR=1
        ISTACK=0
        IRECONCILE=0
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(hdecrementer)

EXC_REAL_BEGIN(hdecrementer, 0x980, 0x80)
        GEN_INT_ENTRY hdecrementer, virt=0
EXC_REAL_END(hdecrementer, 0x980, 0x80)
EXC_VIRT_BEGIN(hdecrementer, 0x4980, 0x80)
        GEN_INT_ENTRY hdecrementer, virt=1
EXC_VIRT_END(hdecrementer, 0x4980, 0x80)
EXC_COMMON_BEGIN(hdecrementer_common)
        __GEN_COMMON_ENTRY hdecrementer
        /*
         * Hypervisor decrementer interrupts not caught by the KVM test
         * shouldn't occur but are sometimes left pending on exit from a KVM
         * guest.  We don't need to do anything to clear them, as they are
         * edge-triggered.
         *
         * Be careful to avoid touching the kernel stack.
         */
        ld      r10,PACA_EXGEN+EX_CTR(r13)
        mtctr   r10
        mtcrf   0x80,r9
        ld      r9,PACA_EXGEN+EX_R9(r13)
        ld      r10,PACA_EXGEN+EX_R10(r13)
        ld      r11,PACA_EXGEN+EX_R11(r13)
        ld      r12,PACA_EXGEN+EX_R12(r13)
        ld      r13,PACA_EXGEN+EX_R13(r13)
        HRFI_TO_KERNEL

        GEN_KVM hdecrementer


/**
 * Interrupt 0xa00 - Directed Privileged Doorbell Interrupt.
 * This is an asynchronous interrupt in response to a msgsndp doorbell.
 * It is maskable in hardware by clearing MSR[EE], and soft-maskable with
 * IRQS_DISABLED mask (i.e., local_irq_disable()).
 *
 * Handling:
 * Guests may use this for IPIs between threads in a core if the
 * hypervisor supports it. NVGPRS are not saved (see 0x500).
 *
 * If soft masked, the masked handler will note the pending interrupt for
 * replay, leaving MSR[EE] enabled in the interrupted context because the
 * doorbells are edge triggered.
 */
INT_DEFINE_BEGIN(doorbell_super)
        IVEC=0xa00
        IMASK=IRQS_DISABLED
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(doorbell_super)

EXC_REAL_BEGIN(doorbell_super, 0xa00, 0x100)
        GEN_INT_ENTRY doorbell_super, virt=0
EXC_REAL_END(doorbell_super, 0xa00, 0x100)
EXC_VIRT_BEGIN(doorbell_super, 0x4a00, 0x100)
        GEN_INT_ENTRY doorbell_super, virt=1
EXC_VIRT_END(doorbell_super, 0x4a00, 0x100)
EXC_COMMON_BEGIN(doorbell_super_common)
        GEN_COMMON doorbell_super
        FINISH_NAP
        RUNLATCH_ON
        addi    r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_DOORBELL
        bl      doorbell_exception
#else
        bl      unknown_exception
#endif
        b       interrupt_return

        GEN_KVM doorbell_super


EXC_REAL_NONE(0xb00, 0x100)
EXC_VIRT_NONE(0x4b00, 0x100)

/**
 * Interrupt 0xc00 - System Call Interrupt (syscall, hcall).
 * This is a synchronous interrupt invoked with the "sc" instruction. The
 * system call is invoked with "sc 0" and does not alter the HV bit, so it
 * is directed to the currently running OS. The hypercall is invoked with
 * "sc 1" and it sets HV=1, so it elevates to hypervisor.
 *
 * In HPT, sc 1 always goes to 0xc00 real mode. In RADIX, sc 1 can go to
 * 0x4c00 virtual mode.
 *
 * Handling:
 * If the KVM test fires then it was due to a hypercall and is accordingly
 * routed to KVM. Otherwise this executes a normal Linux system call.
 *
 * Call convention:
 *
 * syscall and hypercalls register conventions are documented in
 * Documentation/powerpc/syscall64-abi.rst and
 * Documentation/powerpc/papr_hcalls.rst respectively.
 *
 * The intersection of volatile registers that don't contain possible
 * inputs is: cr0, xer, ctr. We may use these as scratch regs upon entry
 * without saving, though xer is not a good idea to use, as hardware may
 * interpret some bits so it may be costly to change them.
 */
INT_DEFINE_BEGIN(system_call)
        IVEC=0xc00
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(system_call)

.macro SYSTEM_CALL virt
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
        /*
         * There is a little bit of juggling to get syscall and hcall
         * working well. Save r13 in ctr to avoid using SPRG scratch
         * register.
         *
         * Userspace syscalls have already saved the PPR, hcalls must save
         * it before setting HMT_MEDIUM.
         */
        mtctr   r13
        GET_PACA(r13)
        std     r10,PACA_EXGEN+EX_R10(r13)
        INTERRUPT_TO_KERNEL
        KVMTEST system_call /* uses r10, branch to system_call_kvm */
        mfctr   r9
#else
        mr      r9,r13
        GET_PACA(r13)
        INTERRUPT_TO_KERNEL
#endif

#ifdef CONFIG_PPC_FAST_ENDIAN_SWITCH
BEGIN_FTR_SECTION
        cmpdi   r0,0x1ebe
        beq-    1f
END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
#endif

        /* We reach here with PACA in r13, r13 in r9. */
        mfspr   r11,SPRN_SRR0
        mfspr   r12,SPRN_SRR1

        HMT_MEDIUM

        .if ! \virt
        __LOAD_HANDLER(r10, system_call_common)
        mtspr   SPRN_SRR0,r10
        ld      r10,PACAKMSR(r13)
        mtspr   SPRN_SRR1,r10
        RFI_TO_KERNEL
        b       .       /* prevent speculative execution */
        .else
        li      r10,MSR_RI
        mtmsrd  r10,1                   /* Set RI (EE=0) */
#ifdef CONFIG_RELOCATABLE
        __LOAD_HANDLER(r10, system_call_common)
        mtctr   r10
        bctr
#else
        b       system_call_common
#endif
        .endif

#ifdef CONFIG_PPC_FAST_ENDIAN_SWITCH
        /* Fast LE/BE switch system call */
1:      mfspr   r12,SPRN_SRR1
        xori    r12,r12,MSR_LE
        mtspr   SPRN_SRR1,r12
        mr      r13,r9
        RFI_TO_USER     /* return to userspace */
        b       .       /* prevent speculative execution */
#endif
.endm

EXC_REAL_BEGIN(system_call, 0xc00, 0x100)
        SYSTEM_CALL 0
EXC_REAL_END(system_call, 0xc00, 0x100)
EXC_VIRT_BEGIN(system_call, 0x4c00, 0x100)
        SYSTEM_CALL 1
EXC_VIRT_END(system_call, 0x4c00, 0x100)

#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
TRAMP_REAL_BEGIN(system_call_kvm)
        /*
         * This is a hcall, so register convention is as above, with these
         * differences:
         * r13 = PACA
         * ctr = orig r13
         * orig r10 saved in PACA
         */
         /*
          * Save the PPR (on systems that support it) before changing to
          * HMT_MEDIUM. That allows the KVM code to save that value into the
          * guest state (it is the guest's PPR value).
          */
BEGIN_FTR_SECTION
        mfspr   r10,SPRN_PPR
        std     r10,HSTATE_PPR(r13)
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
        HMT_MEDIUM
        mfctr   r10
        SET_SCRATCH0(r10)
        mfcr    r10
        std     r12,HSTATE_SCRATCH0(r13)
        sldi    r12,r10,32
        ori     r12,r12,0xc00
#ifdef CONFIG_RELOCATABLE
        /*
         * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
         * outside the head section.
         */
        __LOAD_FAR_HANDLER(r10, kvmppc_interrupt)
        mtctr   r10
        ld      r10,PACA_EXGEN+EX_R10(r13)
        bctr
#else
        ld      r10,PACA_EXGEN+EX_R10(r13)
        b       kvmppc_interrupt
#endif
#endif


/**
 * Interrupt 0xd00 - Trace Interrupt.
 * This is a synchronous interrupt in response to instruction step or
 * breakpoint faults.
 */
INT_DEFINE_BEGIN(single_step)
        IVEC=0xd00
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(single_step)

EXC_REAL_BEGIN(single_step, 0xd00, 0x100)
        GEN_INT_ENTRY single_step, virt=0
EXC_REAL_END(single_step, 0xd00, 0x100)
EXC_VIRT_BEGIN(single_step, 0x4d00, 0x100)
        GEN_INT_ENTRY single_step, virt=1
EXC_VIRT_END(single_step, 0x4d00, 0x100)
EXC_COMMON_BEGIN(single_step_common)
        GEN_COMMON single_step
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      single_step_exception
        b       interrupt_return

        GEN_KVM single_step


/**
 * Interrupt 0xe00 - Hypervisor Data Storage Interrupt (HDSI).
 * This is a synchronous interrupt in response to an MMU fault caused by a
 * guest data access.
 *
 * Handling:
 * This should always get routed to KVM. In radix MMU mode, this is caused
 * by a guest nested radix access that can't be performed due to the
 * partition scope page table. In hash mode, this can be caused by guests
 * running with translation disabled (virtual real mode) or with VPM enabled.
 * KVM will update the page table structures or disallow the access.
 */
INT_DEFINE_BEGIN(h_data_storage)
        IVEC=0xe00
        IHSRR=1
        IDAR=1
        IDSISR=1
        IKVM_SKIP=1
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(h_data_storage)

EXC_REAL_BEGIN(h_data_storage, 0xe00, 0x20)
        GEN_INT_ENTRY h_data_storage, virt=0, ool=1
EXC_REAL_END(h_data_storage, 0xe00, 0x20)
EXC_VIRT_BEGIN(h_data_storage, 0x4e00, 0x20)
        GEN_INT_ENTRY h_data_storage, virt=1, ool=1
EXC_VIRT_END(h_data_storage, 0x4e00, 0x20)
EXC_COMMON_BEGIN(h_data_storage_common)
        GEN_COMMON h_data_storage
        addi    r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
        ld      r4,_DAR(r1)
        li      r5,SIGSEGV
        bl      bad_page_fault
MMU_FTR_SECTION_ELSE
        bl      unknown_exception
ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
        b       interrupt_return

        GEN_KVM h_data_storage


/**
 * Interrupt 0xe20 - Hypervisor Instruction Storage Interrupt (HISI).
 * This is a synchronous interrupt in response to an MMU fault caused by a
 * guest instruction fetch, similar to HDSI.
 */
INT_DEFINE_BEGIN(h_instr_storage)
        IVEC=0xe20
        IHSRR=1
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(h_instr_storage)

EXC_REAL_BEGIN(h_instr_storage, 0xe20, 0x20)
        GEN_INT_ENTRY h_instr_storage, virt=0, ool=1
EXC_REAL_END(h_instr_storage, 0xe20, 0x20)
EXC_VIRT_BEGIN(h_instr_storage, 0x4e20, 0x20)
        GEN_INT_ENTRY h_instr_storage, virt=1, ool=1
EXC_VIRT_END(h_instr_storage, 0x4e20, 0x20)
EXC_COMMON_BEGIN(h_instr_storage_common)
        GEN_COMMON h_instr_storage
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      unknown_exception
        b       interrupt_return

        GEN_KVM h_instr_storage


/**
 * Interrupt 0xe40 - Hypervisor Emulation Assistance Interrupt.
 */
INT_DEFINE_BEGIN(emulation_assist)
        IVEC=0xe40
        IHSRR=1
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(emulation_assist)

EXC_REAL_BEGIN(emulation_assist, 0xe40, 0x20)
        GEN_INT_ENTRY emulation_assist, virt=0, ool=1
EXC_REAL_END(emulation_assist, 0xe40, 0x20)
EXC_VIRT_BEGIN(emulation_assist, 0x4e40, 0x20)
        GEN_INT_ENTRY emulation_assist, virt=1, ool=1
EXC_VIRT_END(emulation_assist, 0x4e40, 0x20)
EXC_COMMON_BEGIN(emulation_assist_common)
        GEN_COMMON emulation_assist
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      emulation_assist_interrupt
        REST_NVGPRS(r1) /* instruction emulation may change GPRs */
        b       interrupt_return

        GEN_KVM emulation_assist


/**
 * Interrupt 0xe60 - Hypervisor Maintenance Interrupt (HMI).
 * This is an asynchronous interrupt caused by a Hypervisor Maintenance
 * Exception. It is always taken in real mode but uses HSRR registers
 * unlike SRESET and MCE.
 *
 * It is maskable in hardware by clearing MSR[EE], and partially soft-maskable
 * with IRQS_DISABLED mask (i.e., local_irq_disable()).
 *
 * Handling:
 * This is a special case, this is handled similarly to machine checks, with an
 * initial real mode handler that is not soft-masked, which attempts to fix the
 * problem. Then a regular handler which is soft-maskable and reports the
 * problem.
 *
 * The emergency stack is used for the early real mode handler.
 *
 * XXX: unclear why MCE and HMI schemes could not be made common, e.g.,
 * either use soft-masking for the MCE, or use irq_work for the HMI.
 *
 * KVM:
 * Unlike MCE, this calls into KVM without calling the real mode handler
 * first.
 */
INT_DEFINE_BEGIN(hmi_exception_early)
        IVEC=0xe60
        IHSRR=1
        IREALMODE_COMMON=1
        ISTACK=0
        IRECONCILE=0
        IKUAP=0 /* We don't touch AMR here, we never go to virtual mode */
        IKVM_REAL=1
INT_DEFINE_END(hmi_exception_early)

INT_DEFINE_BEGIN(hmi_exception)
        IVEC=0xe60
        IHSRR=1
        IMASK=IRQS_DISABLED
        IKVM_REAL=1
INT_DEFINE_END(hmi_exception)

EXC_REAL_BEGIN(hmi_exception, 0xe60, 0x20)
        GEN_INT_ENTRY hmi_exception_early, virt=0, ool=1
EXC_REAL_END(hmi_exception, 0xe60, 0x20)
EXC_VIRT_NONE(0x4e60, 0x20)

EXC_COMMON_BEGIN(hmi_exception_early_common)
        __GEN_REALMODE_COMMON_ENTRY hmi_exception_early

        mr      r10,r1                  /* Save r1 */
        ld      r1,PACAEMERGSP(r13)     /* Use emergency stack for realmode */
        subi    r1,r1,INT_FRAME_SIZE    /* alloc stack frame            */

        __GEN_COMMON_BODY hmi_exception_early

        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      hmi_exception_realmode
        cmpdi   cr0,r3,0
        bne     1f

        EXCEPTION_RESTORE_REGS hsrr=1
        HRFI_TO_USER_OR_KERNEL

1:
        /*
         * Go to virtual mode and pull the HMI event information from
         * firmware.
         */
        EXCEPTION_RESTORE_REGS hsrr=1
        GEN_INT_ENTRY hmi_exception, virt=0

        GEN_KVM hmi_exception_early

EXC_COMMON_BEGIN(hmi_exception_common)
        GEN_COMMON hmi_exception
        FINISH_NAP
        RUNLATCH_ON
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      handle_hmi_exception
        b       interrupt_return

        GEN_KVM hmi_exception


/**
 * Interrupt 0xe80 - Directed Hypervisor Doorbell Interrupt.
 * This is an asynchronous interrupt in response to a msgsnd doorbell.
 * Similar to the 0xa00 doorbell but for host rather than guest.
 */
INT_DEFINE_BEGIN(h_doorbell)
        IVEC=0xe80
        IHSRR=1
        IMASK=IRQS_DISABLED
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(h_doorbell)

EXC_REAL_BEGIN(h_doorbell, 0xe80, 0x20)
        GEN_INT_ENTRY h_doorbell, virt=0, ool=1
EXC_REAL_END(h_doorbell, 0xe80, 0x20)
EXC_VIRT_BEGIN(h_doorbell, 0x4e80, 0x20)
        GEN_INT_ENTRY h_doorbell, virt=1, ool=1
EXC_VIRT_END(h_doorbell, 0x4e80, 0x20)
EXC_COMMON_BEGIN(h_doorbell_common)
        GEN_COMMON h_doorbell
        FINISH_NAP
        RUNLATCH_ON
        addi    r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_DOORBELL
        bl      doorbell_exception
#else
        bl      unknown_exception
#endif
        b       interrupt_return

        GEN_KVM h_doorbell


/**
 * Interrupt 0xea0 - Hypervisor Virtualization Interrupt.
 * This is an asynchronous interrupt in response to an "external exception".
 * Similar to 0x500 but for host only.
 */
INT_DEFINE_BEGIN(h_virt_irq)
        IVEC=0xea0
        IHSRR=1
        IMASK=IRQS_DISABLED
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(h_virt_irq)

EXC_REAL_BEGIN(h_virt_irq, 0xea0, 0x20)
        GEN_INT_ENTRY h_virt_irq, virt=0, ool=1
EXC_REAL_END(h_virt_irq, 0xea0, 0x20)
EXC_VIRT_BEGIN(h_virt_irq, 0x4ea0, 0x20)
        GEN_INT_ENTRY h_virt_irq, virt=1, ool=1
EXC_VIRT_END(h_virt_irq, 0x4ea0, 0x20)
EXC_COMMON_BEGIN(h_virt_irq_common)
        GEN_COMMON h_virt_irq
        FINISH_NAP
        RUNLATCH_ON
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      do_IRQ
        b       interrupt_return

        GEN_KVM h_virt_irq


EXC_REAL_NONE(0xec0, 0x20)
EXC_VIRT_NONE(0x4ec0, 0x20)
EXC_REAL_NONE(0xee0, 0x20)
EXC_VIRT_NONE(0x4ee0, 0x20)


/*
 * Interrupt 0xf00 - Performance Monitor Interrupt (PMI, PMU).
 * This is an asynchronous interrupt in response to a PMU exception.
 * It is maskable in hardware by clearing MSR[EE], and soft-maskable with
 * IRQS_PMI_DISABLED mask (NOTE: NOT local_irq_disable()).
 *
 * Handling:
 * This calls into the perf subsystem.
 *
 * Like the watchdog soft-nmi, it appears an NMI interrupt to Linux, in that it
 * runs under local_irq_disable. However it may be soft-masked in
 * powerpc-specific code.
 *
 * If soft masked, the masked handler will note the pending interrupt for
 * replay, and clear MSR[EE] in the interrupted context.
 */
INT_DEFINE_BEGIN(performance_monitor)
        IVEC=0xf00
        IMASK=IRQS_PMI_DISABLED
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(performance_monitor)

EXC_REAL_BEGIN(performance_monitor, 0xf00, 0x20)
        GEN_INT_ENTRY performance_monitor, virt=0, ool=1
EXC_REAL_END(performance_monitor, 0xf00, 0x20)
EXC_VIRT_BEGIN(performance_monitor, 0x4f00, 0x20)
        GEN_INT_ENTRY performance_monitor, virt=1, ool=1
EXC_VIRT_END(performance_monitor, 0x4f00, 0x20)
EXC_COMMON_BEGIN(performance_monitor_common)
        GEN_COMMON performance_monitor
        FINISH_NAP
        RUNLATCH_ON
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      performance_monitor_exception
        b       interrupt_return

        GEN_KVM performance_monitor


/**
 * Interrupt 0xf20 - Vector Unavailable Interrupt.
 * This is a synchronous interrupt in response to
 * executing a vector (or altivec) instruction with MSR[VEC]=0.
 * Similar to FP unavailable.
 */
INT_DEFINE_BEGIN(altivec_unavailable)
        IVEC=0xf20
        IRECONCILE=0
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(altivec_unavailable)

EXC_REAL_BEGIN(altivec_unavailable, 0xf20, 0x20)
        GEN_INT_ENTRY altivec_unavailable, virt=0, ool=1
EXC_REAL_END(altivec_unavailable, 0xf20, 0x20)
EXC_VIRT_BEGIN(altivec_unavailable, 0x4f20, 0x20)
        GEN_INT_ENTRY altivec_unavailable, virt=1, ool=1
EXC_VIRT_END(altivec_unavailable, 0x4f20, 0x20)
EXC_COMMON_BEGIN(altivec_unavailable_common)
        GEN_COMMON altivec_unavailable
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
        beq     1f
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  BEGIN_FTR_SECTION_NESTED(69)
        /* Test if 2 TM state bits are zero.  If non-zero (ie. userspace was in
         * transaction), go do TM stuff
         */
        rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
        bne-    2f
  END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
#endif
        bl      load_up_altivec
        b       fast_interrupt_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2:      /* User process was in a transaction */
        RECONCILE_IRQ_STATE(r10, r11)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      altivec_unavailable_tm
        b       interrupt_return
#endif
1:
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
        RECONCILE_IRQ_STATE(r10, r11)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      altivec_unavailable_exception
        b       interrupt_return

        GEN_KVM altivec_unavailable


/**
 * Interrupt 0xf40 - VSX Unavailable Interrupt.
 * This is a synchronous interrupt in response to
 * executing a VSX instruction with MSR[VSX]=0.
 * Similar to FP unavailable.
 */
INT_DEFINE_BEGIN(vsx_unavailable)
        IVEC=0xf40
        IRECONCILE=0
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(vsx_unavailable)

EXC_REAL_BEGIN(vsx_unavailable, 0xf40, 0x20)
        GEN_INT_ENTRY vsx_unavailable, virt=0, ool=1
EXC_REAL_END(vsx_unavailable, 0xf40, 0x20)
EXC_VIRT_BEGIN(vsx_unavailable, 0x4f40, 0x20)
        GEN_INT_ENTRY vsx_unavailable, virt=1, ool=1
EXC_VIRT_END(vsx_unavailable, 0x4f40, 0x20)
EXC_COMMON_BEGIN(vsx_unavailable_common)
        GEN_COMMON vsx_unavailable
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
        beq     1f
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  BEGIN_FTR_SECTION_NESTED(69)
        /* Test if 2 TM state bits are zero.  If non-zero (ie. userspace was in
         * transaction), go do TM stuff
         */
        rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
        bne-    2f
  END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
#endif
        b       load_up_vsx
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2:      /* User process was in a transaction */
        RECONCILE_IRQ_STATE(r10, r11)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      vsx_unavailable_tm
        b       interrupt_return
#endif
1:
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
        RECONCILE_IRQ_STATE(r10, r11)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      vsx_unavailable_exception
        b       interrupt_return

        GEN_KVM vsx_unavailable


/**
 * Interrupt 0xf60 - Facility Unavailable Interrupt.
 * This is a synchronous interrupt in response to
 * executing an instruction without access to the facility that can be
 * resolved by the OS (e.g., FSCR, MSR).
 * Similar to FP unavailable.
 */
INT_DEFINE_BEGIN(facility_unavailable)
        IVEC=0xf60
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(facility_unavailable)

EXC_REAL_BEGIN(facility_unavailable, 0xf60, 0x20)
        GEN_INT_ENTRY facility_unavailable, virt=0, ool=1
EXC_REAL_END(facility_unavailable, 0xf60, 0x20)
EXC_VIRT_BEGIN(facility_unavailable, 0x4f60, 0x20)
        GEN_INT_ENTRY facility_unavailable, virt=1, ool=1
EXC_VIRT_END(facility_unavailable, 0x4f60, 0x20)
EXC_COMMON_BEGIN(facility_unavailable_common)
        GEN_COMMON facility_unavailable
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      facility_unavailable_exception
        REST_NVGPRS(r1) /* instruction emulation may change GPRs */
        b       interrupt_return

        GEN_KVM facility_unavailable


/**
 * Interrupt 0xf60 - Hypervisor Facility Unavailable Interrupt.
 * This is a synchronous interrupt in response to
 * executing an instruction without access to the facility that can only
 * be resolved in HV mode (e.g., HFSCR).
 * Similar to FP unavailable.
 */
INT_DEFINE_BEGIN(h_facility_unavailable)
        IVEC=0xf80
        IHSRR=1
        IKVM_REAL=1
        IKVM_VIRT=1
INT_DEFINE_END(h_facility_unavailable)

EXC_REAL_BEGIN(h_facility_unavailable, 0xf80, 0x20)
        GEN_INT_ENTRY h_facility_unavailable, virt=0, ool=1
EXC_REAL_END(h_facility_unavailable, 0xf80, 0x20)
EXC_VIRT_BEGIN(h_facility_unavailable, 0x4f80, 0x20)
        GEN_INT_ENTRY h_facility_unavailable, virt=1, ool=1
EXC_VIRT_END(h_facility_unavailable, 0x4f80, 0x20)
EXC_COMMON_BEGIN(h_facility_unavailable_common)
        GEN_COMMON h_facility_unavailable
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      facility_unavailable_exception
        REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
        b       interrupt_return

        GEN_KVM h_facility_unavailable


EXC_REAL_NONE(0xfa0, 0x20)
EXC_VIRT_NONE(0x4fa0, 0x20)
EXC_REAL_NONE(0xfc0, 0x20)
EXC_VIRT_NONE(0x4fc0, 0x20)
EXC_REAL_NONE(0xfe0, 0x20)
EXC_VIRT_NONE(0x4fe0, 0x20)

EXC_REAL_NONE(0x1000, 0x100)
EXC_VIRT_NONE(0x5000, 0x100)
EXC_REAL_NONE(0x1100, 0x100)
EXC_VIRT_NONE(0x5100, 0x100)

#ifdef CONFIG_CBE_RAS
INT_DEFINE_BEGIN(cbe_system_error)
        IVEC=0x1200
        IHSRR=1
        IKVM_SKIP=1
        IKVM_REAL=1
INT_DEFINE_END(cbe_system_error)

EXC_REAL_BEGIN(cbe_system_error, 0x1200, 0x100)
        GEN_INT_ENTRY cbe_system_error, virt=0
EXC_REAL_END(cbe_system_error, 0x1200, 0x100)
EXC_VIRT_NONE(0x5200, 0x100)
EXC_COMMON_BEGIN(cbe_system_error_common)
        GEN_COMMON cbe_system_error
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      cbe_system_error_exception
        b       interrupt_return

        GEN_KVM cbe_system_error

#else /* CONFIG_CBE_RAS */
EXC_REAL_NONE(0x1200, 0x100)
EXC_VIRT_NONE(0x5200, 0x100)
#endif


INT_DEFINE_BEGIN(instruction_breakpoint)
        IVEC=0x1300
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_SKIP=1
        IKVM_REAL=1
#endif
INT_DEFINE_END(instruction_breakpoint)

EXC_REAL_BEGIN(instruction_breakpoint, 0x1300, 0x100)
        GEN_INT_ENTRY instruction_breakpoint, virt=0
EXC_REAL_END(instruction_breakpoint, 0x1300, 0x100)
EXC_VIRT_BEGIN(instruction_breakpoint, 0x5300, 0x100)
        GEN_INT_ENTRY instruction_breakpoint, virt=1
EXC_VIRT_END(instruction_breakpoint, 0x5300, 0x100)
EXC_COMMON_BEGIN(instruction_breakpoint_common)
        GEN_COMMON instruction_breakpoint
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      instruction_breakpoint_exception
        b       interrupt_return

        GEN_KVM instruction_breakpoint


EXC_REAL_NONE(0x1400, 0x100)
EXC_VIRT_NONE(0x5400, 0x100)

/**
 * Interrupt 0x1500 - Soft Patch Interrupt
 *
 * Handling:
 * This is an implementation specific interrupt which can be used for a
 * range of exceptions.
 *
 * This interrupt handler is unique in that it runs the denormal assist
 * code even for guests (and even in guest context) without going to KVM,
 * for speed. POWER9 does not raise denorm exceptions, so this special case
 * could be phased out in future to reduce special cases.
 */
INT_DEFINE_BEGIN(denorm_exception)
        IVEC=0x1500
        IHSRR=1
        IBRANCH_TO_COMMON=0
        IKVM_REAL=1
INT_DEFINE_END(denorm_exception)

EXC_REAL_BEGIN(denorm_exception, 0x1500, 0x100)
        GEN_INT_ENTRY denorm_exception, virt=0
#ifdef CONFIG_PPC_DENORMALISATION
        andis.  r10,r12,(HSRR1_DENORM)@h /* denorm? */
        bne+    denorm_assist
#endif
        GEN_BRANCH_TO_COMMON denorm_exception, virt=0
EXC_REAL_END(denorm_exception, 0x1500, 0x100)
#ifdef CONFIG_PPC_DENORMALISATION
EXC_VIRT_BEGIN(denorm_exception, 0x5500, 0x100)
        GEN_INT_ENTRY denorm_exception, virt=1
        andis.  r10,r12,(HSRR1_DENORM)@h /* denorm? */
        bne+    denorm_assist
        GEN_BRANCH_TO_COMMON denorm_exception, virt=1
EXC_VIRT_END(denorm_exception, 0x5500, 0x100)
#else
EXC_VIRT_NONE(0x5500, 0x100)
#endif

#ifdef CONFIG_PPC_DENORMALISATION
TRAMP_REAL_BEGIN(denorm_assist)
BEGIN_FTR_SECTION
/*
 * To denormalise we need to move a copy of the register to itself.
 * For POWER6 do that here for all FP regs.
 */
        mfmsr   r10
        ori     r10,r10,(MSR_FP|MSR_FE0|MSR_FE1)
        xori    r10,r10,(MSR_FE0|MSR_FE1)
        mtmsrd  r10
        sync

        .Lreg=0
        .rept 32
        fmr     .Lreg,.Lreg
        .Lreg=.Lreg+1
        .endr

FTR_SECTION_ELSE
/*
 * To denormalise we need to move a copy of the register to itself.
 * For POWER7 do that here for the first 32 VSX registers only.
 */
        mfmsr   r10
        oris    r10,r10,MSR_VSX@h
        mtmsrd  r10
        sync

        .Lreg=0
        .rept 32
        XVCPSGNDP(.Lreg,.Lreg,.Lreg)
        .Lreg=.Lreg+1
        .endr

ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_206)

BEGIN_FTR_SECTION
        b       denorm_done
END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
/*
 * To denormalise we need to move a copy of the register to itself.
 * For POWER8 we need to do that for all 64 VSX registers
 */
        .Lreg=32
        .rept 32
        XVCPSGNDP(.Lreg,.Lreg,.Lreg)
        .Lreg=.Lreg+1
        .endr

denorm_done:
        mfspr   r11,SPRN_HSRR0
        subi    r11,r11,4
        mtspr   SPRN_HSRR0,r11
        mtcrf   0x80,r9
        ld      r9,PACA_EXGEN+EX_R9(r13)
BEGIN_FTR_SECTION
        ld      r10,PACA_EXGEN+EX_PPR(r13)
        mtspr   SPRN_PPR,r10
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
BEGIN_FTR_SECTION
        ld      r10,PACA_EXGEN+EX_CFAR(r13)
        mtspr   SPRN_CFAR,r10
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
        ld      r10,PACA_EXGEN+EX_R10(r13)
        ld      r11,PACA_EXGEN+EX_R11(r13)
        ld      r12,PACA_EXGEN+EX_R12(r13)
        ld      r13,PACA_EXGEN+EX_R13(r13)
        HRFI_TO_UNKNOWN
        b       .
#endif

EXC_COMMON_BEGIN(denorm_exception_common)
        GEN_COMMON denorm_exception
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      unknown_exception
        b       interrupt_return

        GEN_KVM denorm_exception


#ifdef CONFIG_CBE_RAS
INT_DEFINE_BEGIN(cbe_maintenance)
        IVEC=0x1600
        IHSRR=1
        IKVM_SKIP=1
        IKVM_REAL=1
INT_DEFINE_END(cbe_maintenance)

EXC_REAL_BEGIN(cbe_maintenance, 0x1600, 0x100)
        GEN_INT_ENTRY cbe_maintenance, virt=0
EXC_REAL_END(cbe_maintenance, 0x1600, 0x100)
EXC_VIRT_NONE(0x5600, 0x100)
EXC_COMMON_BEGIN(cbe_maintenance_common)
        GEN_COMMON cbe_maintenance
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      cbe_maintenance_exception
        b       interrupt_return

        GEN_KVM cbe_maintenance

#else /* CONFIG_CBE_RAS */
EXC_REAL_NONE(0x1600, 0x100)
EXC_VIRT_NONE(0x5600, 0x100)
#endif


INT_DEFINE_BEGIN(altivec_assist)
        IVEC=0x1700
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
        IKVM_REAL=1
#endif
INT_DEFINE_END(altivec_assist)

EXC_REAL_BEGIN(altivec_assist, 0x1700, 0x100)
        GEN_INT_ENTRY altivec_assist, virt=0
EXC_REAL_END(altivec_assist, 0x1700, 0x100)
EXC_VIRT_BEGIN(altivec_assist, 0x5700, 0x100)
        GEN_INT_ENTRY altivec_assist, virt=1
EXC_VIRT_END(altivec_assist, 0x5700, 0x100)
EXC_COMMON_BEGIN(altivec_assist_common)
        GEN_COMMON altivec_assist
        addi    r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_ALTIVEC
        bl      altivec_assist_exception
        REST_NVGPRS(r1) /* instruction emulation may change GPRs */
#else
        bl      unknown_exception
#endif
        b       interrupt_return

        GEN_KVM altivec_assist


#ifdef CONFIG_CBE_RAS
INT_DEFINE_BEGIN(cbe_thermal)
        IVEC=0x1800
        IHSRR=1
        IKVM_SKIP=1
        IKVM_REAL=1
INT_DEFINE_END(cbe_thermal)

EXC_REAL_BEGIN(cbe_thermal, 0x1800, 0x100)
        GEN_INT_ENTRY cbe_thermal, virt=0
EXC_REAL_END(cbe_thermal, 0x1800, 0x100)
EXC_VIRT_NONE(0x5800, 0x100)
EXC_COMMON_BEGIN(cbe_thermal_common)
        GEN_COMMON cbe_thermal
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      cbe_thermal_exception
        b       interrupt_return

        GEN_KVM cbe_thermal

#else /* CONFIG_CBE_RAS */
EXC_REAL_NONE(0x1800, 0x100)
EXC_VIRT_NONE(0x5800, 0x100)
#endif


#ifdef CONFIG_PPC_WATCHDOG

INT_DEFINE_BEGIN(soft_nmi)
        IVEC=0x900
        ISTACK=0
        IRECONCILE=0    /* Soft-NMI may fire under local_irq_disable */
INT_DEFINE_END(soft_nmi)

/*
 * Branch to soft_nmi_interrupt using the emergency stack. The emergency
 * stack is one that is usable by maskable interrupts so long as MSR_EE
 * remains off. It is used for recovery when something has corrupted the
 * normal kernel stack, for example. The "soft NMI" must not use the process
 * stack because we want irq disabled sections to avoid touching the stack
 * at all (other than PMU interrupts), so use the emergency stack for this,
 * and run it entirely with interrupts hard disabled.
 */
EXC_COMMON_BEGIN(soft_nmi_common)
        mfspr   r11,SPRN_SRR0
        mr      r10,r1
        ld      r1,PACAEMERGSP(r13)
        subi    r1,r1,INT_FRAME_SIZE
        __GEN_COMMON_BODY soft_nmi

        /*
         * Set IRQS_ALL_DISABLED and save PACAIRQHAPPENED (see
         * system_reset_common)
         */
        li      r10,IRQS_ALL_DISABLED
        stb     r10,PACAIRQSOFTMASK(r13)
        lbz     r10,PACAIRQHAPPENED(r13)
        std     r10,RESULT(r1)
        ori     r10,r10,PACA_IRQ_HARD_DIS
        stb     r10,PACAIRQHAPPENED(r13)

        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      soft_nmi_interrupt

        /* Clear MSR_RI before setting SRR0 and SRR1. */
        li      r9,0
        mtmsrd  r9,1

        /*
         * Restore soft mask settings.
         */
        ld      r10,RESULT(r1)
        stb     r10,PACAIRQHAPPENED(r13)
        ld      r10,SOFTE(r1)
        stb     r10,PACAIRQSOFTMASK(r13)

        kuap_restore_amr r9, r10
        EXCEPTION_RESTORE_REGS hsrr=0
        RFI_TO_KERNEL

#endif /* CONFIG_PPC_WATCHDOG */

/*
 * An interrupt came in while soft-disabled. We set paca->irq_happened, then:
 * - If it was a decrementer interrupt, we bump the dec to max and and return.
 * - If it was a doorbell we return immediately since doorbells are edge
 *   triggered and won't automatically refire.
 * - If it was a HMI we return immediately since we handled it in realmode
 *   and it won't refire.
 * - Else it is one of PACA_IRQ_MUST_HARD_MASK, so hard disable and return.
 * This is called with r10 containing the value to OR to the paca field.
 */
.macro MASKED_INTERRUPT hsrr=0
        .if \hsrr
masked_Hinterrupt:
        .else
masked_interrupt:
        .endif
        lbz     r11,PACAIRQHAPPENED(r13)
        or      r11,r11,r10
        stb     r11,PACAIRQHAPPENED(r13)
        cmpwi   r10,PACA_IRQ_DEC
        bne     1f
        lis     r10,0x7fff
        ori     r10,r10,0xffff
        mtspr   SPRN_DEC,r10
#ifdef CONFIG_PPC_WATCHDOG
        b       soft_nmi_common
#else
        b       2f
#endif
1:      andi.   r10,r10,PACA_IRQ_MUST_HARD_MASK
        beq     2f
        xori    r12,r12,MSR_EE  /* clear MSR_EE */
        .if \hsrr
        mtspr   SPRN_HSRR1,r12
        .else
        mtspr   SPRN_SRR1,r12
        .endif
        ori     r11,r11,PACA_IRQ_HARD_DIS
        stb     r11,PACAIRQHAPPENED(r13)
2:      /* done */
        ld      r10,PACA_EXGEN+EX_CTR(r13)
        mtctr   r10
        mtcrf   0x80,r9
        std     r1,PACAR1(r13)
        ld      r9,PACA_EXGEN+EX_R9(r13)
        ld      r10,PACA_EXGEN+EX_R10(r13)
        ld      r11,PACA_EXGEN+EX_R11(r13)
        ld      r12,PACA_EXGEN+EX_R12(r13)
        ld      r13,PACA_EXGEN+EX_R13(r13)
        /* May return to masked low address where r13 is not set up */
        .if \hsrr
        HRFI_TO_KERNEL
        .else
        RFI_TO_KERNEL
        .endif
        b       .
.endm

TRAMP_REAL_BEGIN(stf_barrier_fallback)
        std     r9,PACA_EXRFI+EX_R9(r13)
        std     r10,PACA_EXRFI+EX_R10(r13)
        sync
        ld      r9,PACA_EXRFI+EX_R9(r13)
        ld      r10,PACA_EXRFI+EX_R10(r13)
        ori     31,31,0
        .rept 14
        b       1f
1:
        .endr
        blr

TRAMP_REAL_BEGIN(rfi_flush_fallback)
        SET_SCRATCH0(r13);
        GET_PACA(r13);
        std     r1,PACA_EXRFI+EX_R12(r13)
        ld      r1,PACAKSAVE(r13)
        std     r9,PACA_EXRFI+EX_R9(r13)
        std     r10,PACA_EXRFI+EX_R10(r13)
        std     r11,PACA_EXRFI+EX_R11(r13)
        mfctr   r9
        ld      r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
        ld      r11,PACA_L1D_FLUSH_SIZE(r13)
        srdi    r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
        mtctr   r11
        DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */

        /* order ld/st prior to dcbt stop all streams with flushing */
        sync

        /*
         * The load adresses are at staggered offsets within cachelines,
         * which suits some pipelines better (on others it should not
         * hurt).
         */
1:
        ld      r11,(0x80 + 8)*0(r10)
        ld      r11,(0x80 + 8)*1(r10)
        ld      r11,(0x80 + 8)*2(r10)
        ld      r11,(0x80 + 8)*3(r10)
        ld      r11,(0x80 + 8)*4(r10)
        ld      r11,(0x80 + 8)*5(r10)
        ld      r11,(0x80 + 8)*6(r10)
        ld      r11,(0x80 + 8)*7(r10)
        addi    r10,r10,0x80*8
        bdnz    1b

        mtctr   r9
        ld      r9,PACA_EXRFI+EX_R9(r13)
        ld      r10,PACA_EXRFI+EX_R10(r13)
        ld      r11,PACA_EXRFI+EX_R11(r13)
        ld      r1,PACA_EXRFI+EX_R12(r13)
        GET_SCRATCH0(r13);
        rfid

TRAMP_REAL_BEGIN(hrfi_flush_fallback)
        SET_SCRATCH0(r13);
        GET_PACA(r13);
        std     r1,PACA_EXRFI+EX_R12(r13)
        ld      r1,PACAKSAVE(r13)
        std     r9,PACA_EXRFI+EX_R9(r13)
        std     r10,PACA_EXRFI+EX_R10(r13)
        std     r11,PACA_EXRFI+EX_R11(r13)
        mfctr   r9
        ld      r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
        ld      r11,PACA_L1D_FLUSH_SIZE(r13)
        srdi    r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
        mtctr   r11
        DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */

        /* order ld/st prior to dcbt stop all streams with flushing */
        sync

        /*
         * The load adresses are at staggered offsets within cachelines,
         * which suits some pipelines better (on others it should not
         * hurt).
         */
1:
        ld      r11,(0x80 + 8)*0(r10)
        ld      r11,(0x80 + 8)*1(r10)
        ld      r11,(0x80 + 8)*2(r10)
        ld      r11,(0x80 + 8)*3(r10)
        ld      r11,(0x80 + 8)*4(r10)
        ld      r11,(0x80 + 8)*5(r10)
        ld      r11,(0x80 + 8)*6(r10)
        ld      r11,(0x80 + 8)*7(r10)
        addi    r10,r10,0x80*8
        bdnz    1b

        mtctr   r9
        ld      r9,PACA_EXRFI+EX_R9(r13)
        ld      r10,PACA_EXRFI+EX_R10(r13)
        ld      r11,PACA_EXRFI+EX_R11(r13)
        ld      r1,PACA_EXRFI+EX_R12(r13)
        GET_SCRATCH0(r13);
        hrfid

TRAMP_REAL_BEGIN(rfscv_flush_fallback)
        /* system call volatile */
        mr      r7,r13
        GET_PACA(r13);
        mr      r8,r1
        ld      r1,PACAKSAVE(r13)
        mfctr   r9
        ld      r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
        ld      r11,PACA_L1D_FLUSH_SIZE(r13)
        srdi    r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
        mtctr   r11
        DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */

        /* order ld/st prior to dcbt stop all streams with flushing */
        sync

        /*
         * The load adresses are at staggered offsets within cachelines,
         * which suits some pipelines better (on others it should not
         * hurt).
         */
1:
        ld      r11,(0x80 + 8)*0(r10)
        ld      r11,(0x80 + 8)*1(r10)
        ld      r11,(0x80 + 8)*2(r10)
        ld      r11,(0x80 + 8)*3(r10)
        ld      r11,(0x80 + 8)*4(r10)
        ld      r11,(0x80 + 8)*5(r10)
        ld      r11,(0x80 + 8)*6(r10)
        ld      r11,(0x80 + 8)*7(r10)
        addi    r10,r10,0x80*8
        bdnz    1b

        mtctr   r9
        li      r9,0
        li      r10,0
        li      r11,0
        mr      r1,r8
        mr      r13,r7
        RFSCV

USE_TEXT_SECTION()
        MASKED_INTERRUPT
        MASKED_INTERRUPT hsrr=1

#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
kvmppc_skip_interrupt:
        /*
         * Here all GPRs are unchanged from when the interrupt happened
         * except for r13, which is saved in SPRG_SCRATCH0.
         */
        mfspr   r13, SPRN_SRR0
        addi    r13, r13, 4
        mtspr   SPRN_SRR0, r13
        GET_SCRATCH0(r13)
        RFI_TO_KERNEL
        b       .

kvmppc_skip_Hinterrupt:
        /*
         * Here all GPRs are unchanged from when the interrupt happened
         * except for r13, which is saved in SPRG_SCRATCH0.
         */
        mfspr   r13, SPRN_HSRR0
        addi    r13, r13, 4
        mtspr   SPRN_HSRR0, r13
        GET_SCRATCH0(r13)
        HRFI_TO_KERNEL
        b       .
#endif

        /*
         * Relocation-on interrupts: A subset of the interrupts can be delivered
         * with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering
         * it.  Addresses are the same as the original interrupt addresses, but
         * offset by 0xc000000000004000.
         * It's impossible to receive interrupts below 0x300 via this mechanism.
         * KVM: None of these traps are from the guest ; anything that escalated
         * to HV=1 from HV=0 is delivered via real mode handlers.
         */

        /*
         * This uses the standard macro, since the original 0x300 vector
         * only has extra guff for STAB-based processors -- which never
         * come here.
         */

EXC_COMMON_BEGIN(ppc64_runlatch_on_trampoline)
        b       __ppc64_runlatch_on

USE_FIXED_SECTION(virt_trampolines)
        /*
         * All code below __end_interrupts is treated as soft-masked. If
         * any code runs here with MSR[EE]=1, it must then cope with pending
         * soft interrupt being raised (i.e., by ensuring it is replayed).
         *
         * The __end_interrupts marker must be past the out-of-line (OOL)
         * handlers, so that they are copied to real address 0x100 when running
         * a relocatable kernel. This ensures they can be reached from the short
         * trampoline handlers (like 0x4f00, 0x4f20, etc.) which branch
         * directly, without using LOAD_HANDLER().
         */
        .align  7
        .globl  __end_interrupts
__end_interrupts:
DEFINE_FIXED_SYMBOL(__end_interrupts)

#ifdef CONFIG_PPC_970_NAP
        /*
         * Called by exception entry code if _TLF_NAPPING was set, this clears
         * the NAPPING flag, and redirects the exception exit to
         * power4_fixup_nap_return.
         */
        .globl power4_fixup_nap
EXC_COMMON_BEGIN(power4_fixup_nap)
        andc    r9,r9,r10
        std     r9,TI_LOCAL_FLAGS(r11)
        LOAD_REG_ADDR(r10, power4_idle_nap_return)
        std     r10,_NIP(r1)
        blr

power4_idle_nap_return:
        blr
#endif

CLOSE_FIXED_SECTION(real_vectors);
CLOSE_FIXED_SECTION(real_trampolines);
CLOSE_FIXED_SECTION(virt_vectors);
CLOSE_FIXED_SECTION(virt_trampolines);

USE_TEXT_SECTION()

/* MSR[RI] should be clear because this uses SRR[01] */
enable_machine_check:
        mflr    r0
        bcl     20,31,$+4
0:      mflr    r3
        addi    r3,r3,(1f - 0b)
        mtspr   SPRN_SRR0,r3
        mfmsr   r3
        ori     r3,r3,MSR_ME
        mtspr   SPRN_SRR1,r3
        RFI_TO_KERNEL
1:      mtlr    r0
        blr

/* MSR[RI] should be clear because this uses SRR[01] */
disable_machine_check:
        mflr    r0
        bcl     20,31,$+4
0:      mflr    r3
        addi    r3,r3,(1f - 0b)
        mtspr   SPRN_SRR0,r3
        mfmsr   r3
        li      r4,MSR_ME
        andc    r3,r3,r4
        mtspr   SPRN_SRR1,r3
        RFI_TO_KERNEL
1:      mtlr    r0
        blr

/*
 * Hash table stuff
 */
        .balign IFETCH_ALIGN_BYTES
do_hash_page:
#ifdef CONFIG_PPC_BOOK3S_64
        lis     r0,(DSISR_BAD_FAULT_64S | DSISR_DABRMATCH | DSISR_KEYFAULT)@h
        ori     r0,r0,DSISR_BAD_FAULT_64S@l
        and.    r0,r5,r0                /* weird error? */
        bne-    handle_page_fault       /* if not, try to insert a HPTE */

        /*
         * If we are in an "NMI" (e.g., an interrupt when soft-disabled), then
         * don't call hash_page, just fail the fault. This is required to
         * prevent re-entrancy problems in the hash code, namely perf
         * interrupts hitting while something holds H_PAGE_BUSY, and taking a
         * hash fault. See the comment in hash_preload().
         */
        ld      r11, PACA_THREAD_INFO(r13)
        lwz     r0,TI_PREEMPT(r11)
        andis.  r0,r0,NMI_MASK@h
        bne     77f

        /*
         * r3 contains the trap number
         * r4 contains the faulting address
         * r5 contains dsisr
         * r6 msr
         *
         * at return r3 = 0 for success, 1 for page fault, negative for error
         */
        bl      __hash_page             /* build HPTE if possible */
        cmpdi   r3,0                    /* see if __hash_page succeeded */

        /* Success */
        beq     interrupt_return        /* Return from exception on success */

        /* Error */
        blt-    13f

        /* Reload DAR/DSISR into r4/r5 for the DABR check below */
        ld      r4,_DAR(r1)
        ld      r5,_DSISR(r1)
#endif /* CONFIG_PPC_BOOK3S_64 */

/* Here we have a page fault that hash_page can't handle. */
handle_page_fault:
11:     andis.  r0,r5,DSISR_DABRMATCH@h
        bne-    handle_dabr_fault
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      do_page_fault
        cmpdi   r3,0
        beq+    interrupt_return
        mr      r5,r3
        addi    r3,r1,STACK_FRAME_OVERHEAD
        ld      r4,_DAR(r1)
        bl      bad_page_fault
        b       interrupt_return

/* We have a data breakpoint exception - handle it */
handle_dabr_fault:
        ld      r4,_DAR(r1)
        ld      r5,_DSISR(r1)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      do_break
        /*
         * do_break() may have changed the NV GPRS while handling a breakpoint.
         * If so, we need to restore them with their updated values.
         */
        REST_NVGPRS(r1)
        b       interrupt_return


#ifdef CONFIG_PPC_BOOK3S_64
/* We have a page fault that hash_page could handle but HV refused
 * the PTE insertion
 */
13:     mr      r5,r3
        addi    r3,r1,STACK_FRAME_OVERHEAD
        ld      r4,_DAR(r1)
        bl      low_hash_fault
        b       interrupt_return
#endif

/*
 * We come here as a result of a DSI at a point where we don't want
 * to call hash_page, such as when we are accessing memory (possibly
 * user memory) inside a PMU interrupt that occurred while interrupts
 * were soft-disabled.  We want to invoke the exception handler for
 * the access, or panic if there isn't a handler.
 */
77:     addi    r3,r1,STACK_FRAME_OVERHEAD
        li      r5,SIGSEGV
        bl      bad_page_fault
        b       interrupt_return