cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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exceptions-64s.S (89381B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * This file contains the 64-bit "server" PowerPC variant
      4 * of the low level exception handling including exception
      5 * vectors, exception return, part of the slb and stab
      6 * handling and other fixed offset specific things.
      7 *
      8 * This file is meant to be #included from head_64.S due to
      9 * position dependent assembly.
     10 *
     11 * Most of this originates from head_64.S and thus has the same
     12 * copyright history.
     13 *
     14 */
     15
     16#include <asm/hw_irq.h>
     17#include <asm/exception-64s.h>
     18#include <asm/ptrace.h>
     19#include <asm/cpuidle.h>
     20#include <asm/head-64.h>
     21#include <asm/feature-fixups.h>
     22#include <asm/kup.h>
     23
     24/*
     25 * Following are fixed section helper macros.
     26 *
     27 * EXC_REAL_BEGIN/END  - real, unrelocated exception vectors
     28 * EXC_VIRT_BEGIN/END  - virt (AIL), unrelocated exception vectors
     29 * TRAMP_REAL_BEGIN    - real, unrelocated helpers (virt may call these)
     30 * TRAMP_VIRT_BEGIN    - virt, unreloc helpers (in practice, real can use)
     31 * EXC_COMMON          - After switching to virtual, relocated mode.
     32 */
     33
     34#define EXC_REAL_BEGIN(name, start, size)			\
     35	FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##name, start, size)
     36
     37#define EXC_REAL_END(name, start, size)				\
     38	FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##name, start, size)
     39
     40#define EXC_VIRT_BEGIN(name, start, size)			\
     41	FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)
     42
     43#define EXC_VIRT_END(name, start, size)				\
     44	FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)
     45
     46#define EXC_COMMON_BEGIN(name)					\
     47	USE_TEXT_SECTION();					\
     48	.balign IFETCH_ALIGN_BYTES;				\
     49	.global name;						\
     50	_ASM_NOKPROBE_SYMBOL(name);				\
     51	DEFINE_FIXED_SYMBOL(name, text);			\
     52name:
     53
     54#define TRAMP_REAL_BEGIN(name)					\
     55	FIXED_SECTION_ENTRY_BEGIN(real_trampolines, name)
     56
     57#define TRAMP_VIRT_BEGIN(name)					\
     58	FIXED_SECTION_ENTRY_BEGIN(virt_trampolines, name)
     59
     60#define EXC_REAL_NONE(start, size)				\
     61	FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##unused, start, size); \
     62	FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##unused, start, size)
     63
     64#define EXC_VIRT_NONE(start, size)				\
     65	FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size); \
     66	FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size)
     67
     68/*
     69 * We're short on space and time in the exception prolog, so we can't
     70 * use the normal LOAD_REG_IMMEDIATE macro to load the address of label.
     71 * Instead we get the base of the kernel from paca->kernelbase and or in the low
     72 * part of label. This requires that the label be within 64KB of kernelbase, and
     73 * that kernelbase be 64K aligned.
     74 */
     75#define LOAD_HANDLER(reg, label)					\
     76	ld	reg,PACAKBASE(r13);	/* get high part of &label */	\
     77	ori	reg,reg,FIXED_SYMBOL_ABS_ADDR(label)
     78
     79#define __LOAD_HANDLER(reg, label, section)					\
     80	ld	reg,PACAKBASE(r13);					\
     81	ori	reg,reg,(ABS_ADDR(label, section))@l
     82
     83/*
     84 * Branches from unrelocated code (e.g., interrupts) to labels outside
     85 * head-y require >64K offsets.
     86 */
     87#define __LOAD_FAR_HANDLER(reg, label, section)					\
     88	ld	reg,PACAKBASE(r13);					\
     89	ori	reg,reg,(ABS_ADDR(label, section))@l;				\
     90	addis	reg,reg,(ABS_ADDR(label, section))@h
     91
     92/*
     93 * Interrupt code generation macros
     94 */
     95#define IVEC		.L_IVEC_\name\()	/* Interrupt vector address */
     96#define IHSRR		.L_IHSRR_\name\()	/* Sets SRR or HSRR registers */
     97#define IHSRR_IF_HVMODE	.L_IHSRR_IF_HVMODE_\name\() /* HSRR if HV else SRR */
     98#define IAREA		.L_IAREA_\name\()	/* PACA save area */
     99#define IVIRT		.L_IVIRT_\name\()	/* Has virt mode entry point */
    100#define IISIDE		.L_IISIDE_\name\()	/* Uses SRR0/1 not DAR/DSISR */
    101#define ICFAR		.L_ICFAR_\name\()	/* Uses CFAR */
    102#define ICFAR_IF_HVMODE	.L_ICFAR_IF_HVMODE_\name\() /* Uses CFAR if HV */
    103#define IDAR		.L_IDAR_\name\()	/* Uses DAR (or SRR0) */
    104#define IDSISR		.L_IDSISR_\name\()	/* Uses DSISR (or SRR1) */
    105#define IBRANCH_TO_COMMON	.L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
    106#define IREALMODE_COMMON	.L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
    107#define IMASK		.L_IMASK_\name\()	/* IRQ soft-mask bit */
    108#define IKVM_REAL	.L_IKVM_REAL_\name\()	/* Real entry tests KVM */
    109#define __IKVM_REAL(name)	.L_IKVM_REAL_ ## name
    110#define IKVM_VIRT	.L_IKVM_VIRT_\name\()	/* Virt entry tests KVM */
    111#define ISTACK		.L_ISTACK_\name\()	/* Set regular kernel stack */
    112#define __ISTACK(name)	.L_ISTACK_ ## name
    113#define IKUAP		.L_IKUAP_\name\()	/* Do KUAP lock */
    114
    115#define INT_DEFINE_BEGIN(n)						\
    116.macro int_define_ ## n name
    117
    118#define INT_DEFINE_END(n)						\
    119.endm ;									\
    120int_define_ ## n n ;							\
    121do_define_int n
    122
    123.macro do_define_int name
    124	.ifndef IVEC
    125		.error "IVEC not defined"
    126	.endif
    127	.ifndef IHSRR
    128		IHSRR=0
    129	.endif
    130	.ifndef IHSRR_IF_HVMODE
    131		IHSRR_IF_HVMODE=0
    132	.endif
    133	.ifndef IAREA
    134		IAREA=PACA_EXGEN
    135	.endif
    136	.ifndef IVIRT
    137		IVIRT=1
    138	.endif
    139	.ifndef IISIDE
    140		IISIDE=0
    141	.endif
    142	.ifndef ICFAR
    143		ICFAR=1
    144	.endif
    145	.ifndef ICFAR_IF_HVMODE
    146		ICFAR_IF_HVMODE=0
    147	.endif
    148	.ifndef IDAR
    149		IDAR=0
    150	.endif
    151	.ifndef IDSISR
    152		IDSISR=0
    153	.endif
    154	.ifndef IBRANCH_TO_COMMON
    155		IBRANCH_TO_COMMON=1
    156	.endif
    157	.ifndef IREALMODE_COMMON
    158		IREALMODE_COMMON=0
    159	.else
    160		.if ! IBRANCH_TO_COMMON
    161			.error "IREALMODE_COMMON=1 but IBRANCH_TO_COMMON=0"
    162		.endif
    163	.endif
    164	.ifndef IMASK
    165		IMASK=0
    166	.endif
    167	.ifndef IKVM_REAL
    168		IKVM_REAL=0
    169	.endif
    170	.ifndef IKVM_VIRT
    171		IKVM_VIRT=0
    172	.endif
    173	.ifndef ISTACK
    174		ISTACK=1
    175	.endif
    176	.ifndef IKUAP
    177		IKUAP=1
    178	.endif
    179.endm
    180
    181/*
    182 * All interrupts which set HSRR registers, as well as SRESET and MCE and
    183 * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
    184 * so they all generally need to test whether they were taken in guest context.
    185 *
    186 * Note: SRESET and MCE may also be sent to the guest by the hypervisor, and be
    187 * taken with MSR[HV]=0.
    188 *
    189 * Interrupts which set SRR registers (with the above exceptions) do not
    190 * elevate to MSR[HV]=1 mode, though most can be taken when running with
    191 * MSR[HV]=1  (e.g., bare metal kernel and userspace). So these interrupts do
    192 * not need to test whether a guest is running because they get delivered to
    193 * the guest directly, including nested HV KVM guests.
    194 *
    195 * The exception is PR KVM, where the guest runs with MSR[PR]=1 and the host
    196 * runs with MSR[HV]=0, so the host takes all interrupts on behalf of the
    197 * guest. PR KVM runs with LPCR[AIL]=0 which causes interrupts to always be
    198 * delivered to the real-mode entry point, therefore such interrupts only test
    199 * KVM in their real mode handlers, and only when PR KVM is possible.
    200 *
    201 * Interrupts that are taken in MSR[HV]=0 and escalate to MSR[HV]=1 are always
    202 * delivered in real-mode when the MMU is in hash mode because the MMU
    203 * registers are not set appropriately to translate host addresses. In nested
    204 * radix mode these can be delivered in virt-mode as the host translations are
    205 * used implicitly (see: effective LPID, effective PID).
    206 */
    207
    208/*
    209 * If an interrupt is taken while a guest is running, it is immediately routed
    210 * to KVM to handle.
    211 */
    212
    213.macro KVMTEST name handler
    214#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
    215	lbz	r10,HSTATE_IN_GUEST(r13)
    216	cmpwi	r10,0
    217	/* HSRR variants have the 0x2 bit added to their trap number */
    218	.if IHSRR_IF_HVMODE
    219	BEGIN_FTR_SECTION
    220	li	r10,(IVEC + 0x2)
    221	FTR_SECTION_ELSE
    222	li	r10,(IVEC)
    223	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
    224	.elseif IHSRR
    225	li	r10,(IVEC + 0x2)
    226	.else
    227	li	r10,(IVEC)
    228	.endif
    229	bne	\handler
    230#endif
    231.endm
    232
    233/*
    234 * This is the BOOK3S interrupt entry code macro.
    235 *
    236 * This can result in one of several things happening:
    237 * - Branch to the _common handler, relocated, in virtual mode.
    238 *   These are normal interrupts (synchronous and asynchronous) handled by
    239 *   the kernel.
    240 * - Branch to KVM, relocated but real mode interrupts remain in real mode.
    241 *   These occur when HSTATE_IN_GUEST is set. The interrupt may be caused by
    242 *   / intended for host or guest kernel, but KVM must always be involved
    243 *   because the machine state is set for guest execution.
    244 * - Branch to the masked handler, unrelocated.
    245 *   These occur when maskable asynchronous interrupts are taken with the
    246 *   irq_soft_mask set.
    247 * - Branch to an "early" handler in real mode but relocated.
    248 *   This is done if early=1. MCE and HMI use these to handle errors in real
    249 *   mode.
    250 * - Fall through and continue executing in real, unrelocated mode.
    251 *   This is done if early=2.
    252 */
    253
    254.macro GEN_BRANCH_TO_COMMON name, virt
    255	.if IREALMODE_COMMON
    256	LOAD_HANDLER(r10, \name\()_common)
    257	mtctr	r10
    258	bctr
    259	.else
    260	.if \virt
    261#ifndef CONFIG_RELOCATABLE
    262	b	\name\()_common_virt
    263#else
    264	LOAD_HANDLER(r10, \name\()_common_virt)
    265	mtctr	r10
    266	bctr
    267#endif
    268	.else
    269	LOAD_HANDLER(r10, \name\()_common_real)
    270	mtctr	r10
    271	bctr
    272	.endif
    273	.endif
    274.endm
    275
    276.macro GEN_INT_ENTRY name, virt, ool=0
    277	SET_SCRATCH0(r13)			/* save r13 */
    278	GET_PACA(r13)
    279	std	r9,IAREA+EX_R9(r13)		/* save r9 */
    280BEGIN_FTR_SECTION
    281	mfspr	r9,SPRN_PPR
    282END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
    283	HMT_MEDIUM
    284	std	r10,IAREA+EX_R10(r13)		/* save r10 - r12 */
    285	.if ICFAR
    286BEGIN_FTR_SECTION
    287	mfspr	r10,SPRN_CFAR
    288END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
    289	.elseif ICFAR_IF_HVMODE
    290BEGIN_FTR_SECTION
    291  BEGIN_FTR_SECTION_NESTED(69)
    292	mfspr	r10,SPRN_CFAR
    293  END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 69)
    294FTR_SECTION_ELSE
    295  BEGIN_FTR_SECTION_NESTED(69)
    296	li	r10,0
    297  END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 69)
    298ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
    299	.endif
    300	.if \ool
    301	.if !\virt
    302	b	tramp_real_\name
    303	.pushsection .text
    304	TRAMP_REAL_BEGIN(tramp_real_\name)
    305	.else
    306	b	tramp_virt_\name
    307	.pushsection .text
    308	TRAMP_VIRT_BEGIN(tramp_virt_\name)
    309	.endif
    310	.endif
    311
    312BEGIN_FTR_SECTION
    313	std	r9,IAREA+EX_PPR(r13)
    314END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
    315	.if ICFAR || ICFAR_IF_HVMODE
    316BEGIN_FTR_SECTION
    317	std	r10,IAREA+EX_CFAR(r13)
    318END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
    319	.endif
    320	INTERRUPT_TO_KERNEL
    321	mfctr	r10
    322	std	r10,IAREA+EX_CTR(r13)
    323	mfcr	r9
    324	std	r11,IAREA+EX_R11(r13)
    325	std	r12,IAREA+EX_R12(r13)
    326
    327	/*
    328	 * DAR/DSISR, SCRATCH0 must be read before setting MSR[RI],
    329	 * because a d-side MCE will clobber those registers so is
    330	 * not recoverable if they are live.
    331	 */
    332	GET_SCRATCH0(r10)
    333	std	r10,IAREA+EX_R13(r13)
    334	.if IDAR && !IISIDE
    335	.if IHSRR
    336	mfspr	r10,SPRN_HDAR
    337	.else
    338	mfspr	r10,SPRN_DAR
    339	.endif
    340	std	r10,IAREA+EX_DAR(r13)
    341	.endif
    342	.if IDSISR && !IISIDE
    343	.if IHSRR
    344	mfspr	r10,SPRN_HDSISR
    345	.else
    346	mfspr	r10,SPRN_DSISR
    347	.endif
    348	stw	r10,IAREA+EX_DSISR(r13)
    349	.endif
    350
    351	.if IHSRR_IF_HVMODE
    352	BEGIN_FTR_SECTION
    353	mfspr	r11,SPRN_HSRR0		/* save HSRR0 */
    354	mfspr	r12,SPRN_HSRR1		/* and HSRR1 */
    355	FTR_SECTION_ELSE
    356	mfspr	r11,SPRN_SRR0		/* save SRR0 */
    357	mfspr	r12,SPRN_SRR1		/* and SRR1 */
    358	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
    359	.elseif IHSRR
    360	mfspr	r11,SPRN_HSRR0		/* save HSRR0 */
    361	mfspr	r12,SPRN_HSRR1		/* and HSRR1 */
    362	.else
    363	mfspr	r11,SPRN_SRR0		/* save SRR0 */
    364	mfspr	r12,SPRN_SRR1		/* and SRR1 */
    365	.endif
    366
    367	.if IBRANCH_TO_COMMON
    368	GEN_BRANCH_TO_COMMON \name \virt
    369	.endif
    370
    371	.if \ool
    372	.popsection
    373	.endif
    374.endm
    375
    376/*
    377 * __GEN_COMMON_ENTRY is required to receive the branch from interrupt
    378 * entry, except in the case of the real-mode handlers which require
    379 * __GEN_REALMODE_COMMON_ENTRY.
    380 *
    381 * This switches to virtual mode and sets MSR[RI].
    382 */
    383.macro __GEN_COMMON_ENTRY name
    384DEFINE_FIXED_SYMBOL(\name\()_common_real, text)
    385\name\()_common_real:
    386	.if IKVM_REAL
    387		KVMTEST \name kvm_interrupt
    388	.endif
    389
    390	ld	r10,PACAKMSR(r13)	/* get MSR value for kernel */
    391	/* MSR[RI] is clear iff using SRR regs */
    392	.if IHSRR_IF_HVMODE
    393	BEGIN_FTR_SECTION
    394	xori	r10,r10,MSR_RI
    395	END_FTR_SECTION_IFCLR(CPU_FTR_HVMODE)
    396	.elseif ! IHSRR
    397	xori	r10,r10,MSR_RI
    398	.endif
    399	mtmsrd	r10
    400
    401	.if IVIRT
    402	.if IKVM_VIRT
    403	b	1f /* skip the virt test coming from real */
    404	.endif
    405
    406	.balign IFETCH_ALIGN_BYTES
    407DEFINE_FIXED_SYMBOL(\name\()_common_virt, text)
    408\name\()_common_virt:
    409	.if IKVM_VIRT
    410		KVMTEST \name kvm_interrupt
    4111:
    412	.endif
    413	.endif /* IVIRT */
    414.endm
    415
    416/*
    417 * Don't switch to virt mode. Used for early MCE and HMI handlers that
    418 * want to run in real mode.
    419 */
    420.macro __GEN_REALMODE_COMMON_ENTRY name
    421DEFINE_FIXED_SYMBOL(\name\()_common_real, text)
    422\name\()_common_real:
    423	.if IKVM_REAL
    424		KVMTEST \name kvm_interrupt
    425	.endif
    426.endm
    427
    428.macro __GEN_COMMON_BODY name
    429	.if IMASK
    430		.if ! ISTACK
    431		.error "No support for masked interrupt to use custom stack"
    432		.endif
    433
    434		/* If coming from user, skip soft-mask tests. */
    435		andi.	r10,r12,MSR_PR
    436		bne	3f
    437
    438		/*
    439		 * Kernel code running below __end_soft_masked may be
    440		 * implicitly soft-masked if it is within the regions
    441		 * in the soft mask table.
    442		 */
    443		LOAD_HANDLER(r10, __end_soft_masked)
    444		cmpld	r11,r10
    445		bge+	1f
    446
    447		/* SEARCH_SOFT_MASK_TABLE clobbers r9,r10,r12 */
    448		mtctr	r12
    449		stw	r9,PACA_EXGEN+EX_CCR(r13)
    450		SEARCH_SOFT_MASK_TABLE
    451		cmpdi	r12,0
    452		mfctr	r12		/* Restore r12 to SRR1 */
    453		lwz	r9,PACA_EXGEN+EX_CCR(r13)
    454		beq	1f		/* Not in soft-mask table */
    455		li	r10,IMASK
    456		b	2f		/* In soft-mask table, always mask */
    457
    458		/* Test the soft mask state against our interrupt's bit */
    4591:		lbz	r10,PACAIRQSOFTMASK(r13)
    4602:		andi.	r10,r10,IMASK
    461		/* Associate vector numbers with bits in paca->irq_happened */
    462		.if IVEC == 0x500 || IVEC == 0xea0
    463		li	r10,PACA_IRQ_EE
    464		.elseif IVEC == 0x900
    465		li	r10,PACA_IRQ_DEC
    466		.elseif IVEC == 0xa00 || IVEC == 0xe80
    467		li	r10,PACA_IRQ_DBELL
    468		.elseif IVEC == 0xe60
    469		li	r10,PACA_IRQ_HMI
    470		.elseif IVEC == 0xf00
    471		li	r10,PACA_IRQ_PMI
    472		.else
    473		.abort "Bad maskable vector"
    474		.endif
    475
    476		.if IHSRR_IF_HVMODE
    477		BEGIN_FTR_SECTION
    478		bne	masked_Hinterrupt
    479		FTR_SECTION_ELSE
    480		bne	masked_interrupt
    481		ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
    482		.elseif IHSRR
    483		bne	masked_Hinterrupt
    484		.else
    485		bne	masked_interrupt
    486		.endif
    487	.endif
    488
    489	.if ISTACK
    490	andi.	r10,r12,MSR_PR		/* See if coming from user	*/
    4913:	mr	r10,r1			/* Save r1			*/
    492	subi	r1,r1,INT_FRAME_SIZE	/* alloc frame on kernel stack	*/
    493	beq-	100f
    494	ld	r1,PACAKSAVE(r13)	/* kernel stack to use		*/
    495100:	tdgei	r1,-INT_FRAME_SIZE	/* trap if r1 is in userspace	*/
    496	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,0
    497	.endif
    498
    499	std	r9,_CCR(r1)		/* save CR in stackframe	*/
    500	std	r11,_NIP(r1)		/* save SRR0 in stackframe	*/
    501	std	r12,_MSR(r1)		/* save SRR1 in stackframe	*/
    502	std	r10,0(r1)		/* make stack chain pointer	*/
    503	std	r0,GPR0(r1)		/* save r0 in stackframe	*/
    504	std	r10,GPR1(r1)		/* save r1 in stackframe	*/
    505
    506	/* Mark our [H]SRRs valid for return */
    507	li	r10,1
    508	.if IHSRR_IF_HVMODE
    509	BEGIN_FTR_SECTION
    510	stb	r10,PACAHSRR_VALID(r13)
    511	FTR_SECTION_ELSE
    512	stb	r10,PACASRR_VALID(r13)
    513	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
    514	.elseif IHSRR
    515	stb	r10,PACAHSRR_VALID(r13)
    516	.else
    517	stb	r10,PACASRR_VALID(r13)
    518	.endif
    519
    520	.if ISTACK
    521	.if IKUAP
    522	kuap_save_amr_and_lock r9, r10, cr1, cr0
    523	.endif
    524	beq	101f			/* if from kernel mode		*/
    525BEGIN_FTR_SECTION
    526	ld	r9,IAREA+EX_PPR(r13)	/* Read PPR from paca		*/
    527	std	r9,_PPR(r1)
    528END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
    529101:
    530	.else
    531	.if IKUAP
    532	kuap_save_amr_and_lock r9, r10, cr1
    533	.endif
    534	.endif
    535
    536	/* Save original regs values from save area to stack frame. */
    537	ld	r9,IAREA+EX_R9(r13)	/* move r9, r10 to stackframe	*/
    538	ld	r10,IAREA+EX_R10(r13)
    539	std	r9,GPR9(r1)
    540	std	r10,GPR10(r1)
    541	ld	r9,IAREA+EX_R11(r13)	/* move r11 - r13 to stackframe	*/
    542	ld	r10,IAREA+EX_R12(r13)
    543	ld	r11,IAREA+EX_R13(r13)
    544	std	r9,GPR11(r1)
    545	std	r10,GPR12(r1)
    546	std	r11,GPR13(r1)
    547
    548	SAVE_NVGPRS(r1)
    549
    550	.if IDAR
    551	.if IISIDE
    552	ld	r10,_NIP(r1)
    553	.else
    554	ld	r10,IAREA+EX_DAR(r13)
    555	.endif
    556	std	r10,_DAR(r1)
    557	.endif
    558
    559	.if IDSISR
    560	.if IISIDE
    561	ld	r10,_MSR(r1)
    562	lis	r11,DSISR_SRR1_MATCH_64S@h
    563	and	r10,r10,r11
    564	.else
    565	lwz	r10,IAREA+EX_DSISR(r13)
    566	.endif
    567	std	r10,_DSISR(r1)
    568	.endif
    569
    570BEGIN_FTR_SECTION
    571	.if ICFAR || ICFAR_IF_HVMODE
    572	ld	r10,IAREA+EX_CFAR(r13)
    573	.else
    574	li	r10,0
    575	.endif
    576	std	r10,ORIG_GPR3(r1)
    577END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
    578	ld	r10,IAREA+EX_CTR(r13)
    579	std	r10,_CTR(r1)
    580	std	r2,GPR2(r1)		/* save r2 in stackframe	*/
    581	SAVE_GPRS(3, 8, r1)		/* save r3 - r8 in stackframe   */
    582	mflr	r9			/* Get LR, later save to stack	*/
    583	ld	r2,PACATOC(r13)		/* get kernel TOC into r2	*/
    584	std	r9,_LINK(r1)
    585	lbz	r10,PACAIRQSOFTMASK(r13)
    586	mfspr	r11,SPRN_XER		/* save XER in stackframe	*/
    587	std	r10,SOFTE(r1)
    588	std	r11,_XER(r1)
    589	li	r9,IVEC
    590	std	r9,_TRAP(r1)		/* set trap number		*/
    591	li	r10,0
    592	ld	r11,exception_marker@toc(r2)
    593	std	r10,RESULT(r1)		/* clear regs->result		*/
    594	std	r11,STACK_FRAME_OVERHEAD-16(r1) /* mark the frame	*/
    595.endm
    596
    597/*
    598 * On entry r13 points to the paca, r9-r13 are saved in the paca,
    599 * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
    600 * SRR1, and relocation is on.
    601 *
    602 * If stack=0, then the stack is already set in r1, and r1 is saved in r10.
    603 * PPR save and CPU accounting is not done for the !stack case (XXX why not?)
    604 */
    605.macro GEN_COMMON name
    606	__GEN_COMMON_ENTRY \name
    607	__GEN_COMMON_BODY \name
    608.endm
    609
    610.macro SEARCH_RESTART_TABLE
    611#ifdef CONFIG_RELOCATABLE
    612	mr	r12,r2
    613	ld	r2,PACATOC(r13)
    614	LOAD_REG_ADDR(r9, __start___restart_table)
    615	LOAD_REG_ADDR(r10, __stop___restart_table)
    616	mr	r2,r12
    617#else
    618	LOAD_REG_IMMEDIATE_SYM(r9, r12, __start___restart_table)
    619	LOAD_REG_IMMEDIATE_SYM(r10, r12, __stop___restart_table)
    620#endif
    621300:
    622	cmpd	r9,r10
    623	beq	302f
    624	ld	r12,0(r9)
    625	cmpld	r11,r12
    626	blt	301f
    627	ld	r12,8(r9)
    628	cmpld	r11,r12
    629	bge	301f
    630	ld	r12,16(r9)
    631	b	303f
    632301:
    633	addi	r9,r9,24
    634	b	300b
    635302:
    636	li	r12,0
    637303:
    638.endm
    639
    640.macro SEARCH_SOFT_MASK_TABLE
    641#ifdef CONFIG_RELOCATABLE
    642	mr	r12,r2
    643	ld	r2,PACATOC(r13)
    644	LOAD_REG_ADDR(r9, __start___soft_mask_table)
    645	LOAD_REG_ADDR(r10, __stop___soft_mask_table)
    646	mr	r2,r12
    647#else
    648	LOAD_REG_IMMEDIATE_SYM(r9, r12, __start___soft_mask_table)
    649	LOAD_REG_IMMEDIATE_SYM(r10, r12, __stop___soft_mask_table)
    650#endif
    651300:
    652	cmpd	r9,r10
    653	beq	302f
    654	ld	r12,0(r9)
    655	cmpld	r11,r12
    656	blt	301f
    657	ld	r12,8(r9)
    658	cmpld	r11,r12
    659	bge	301f
    660	li	r12,1
    661	b	303f
    662301:
    663	addi	r9,r9,16
    664	b	300b
    665302:
    666	li	r12,0
    667303:
    668.endm
    669
    670/*
    671 * Restore all registers including H/SRR0/1 saved in a stack frame of a
    672 * standard exception.
    673 */
    674.macro EXCEPTION_RESTORE_REGS hsrr=0
    675	/* Move original SRR0 and SRR1 into the respective regs */
    676	ld	r9,_MSR(r1)
    677	li	r10,0
    678	.if \hsrr
    679	mtspr	SPRN_HSRR1,r9
    680	stb	r10,PACAHSRR_VALID(r13)
    681	.else
    682	mtspr	SPRN_SRR1,r9
    683	stb	r10,PACASRR_VALID(r13)
    684	.endif
    685	ld	r9,_NIP(r1)
    686	.if \hsrr
    687	mtspr	SPRN_HSRR0,r9
    688	.else
    689	mtspr	SPRN_SRR0,r9
    690	.endif
    691	ld	r9,_CTR(r1)
    692	mtctr	r9
    693	ld	r9,_XER(r1)
    694	mtxer	r9
    695	ld	r9,_LINK(r1)
    696	mtlr	r9
    697	ld	r9,_CCR(r1)
    698	mtcr	r9
    699	REST_GPRS(2, 13, r1)
    700	REST_GPR(0, r1)
    701	/* restore original r1. */
    702	ld	r1,GPR1(r1)
    703.endm
    704
    705/*
    706 * There are a few constraints to be concerned with.
    707 * - Real mode exceptions code/data must be located at their physical location.
    708 * - Virtual mode exceptions must be mapped at their 0xc000... location.
    709 * - Fixed location code must not call directly beyond the __end_interrupts
    710 *   area when built with CONFIG_RELOCATABLE. LOAD_HANDLER / bctr sequence
    711 *   must be used.
    712 * - LOAD_HANDLER targets must be within first 64K of physical 0 /
    713 *   virtual 0xc00...
    714 * - Conditional branch targets must be within +/-32K of caller.
    715 *
    716 * "Virtual exceptions" run with relocation on (MSR_IR=1, MSR_DR=1), and
    717 * therefore don't have to run in physically located code or rfid to
    718 * virtual mode kernel code. However on relocatable kernels they do have
    719 * to branch to KERNELBASE offset because the rest of the kernel (outside
    720 * the exception vectors) may be located elsewhere.
    721 *
    722 * Virtual exceptions correspond with physical, except their entry points
    723 * are offset by 0xc000000000000000 and also tend to get an added 0x4000
    724 * offset applied. Virtual exceptions are enabled with the Alternate
    725 * Interrupt Location (AIL) bit set in the LPCR. However this does not
    726 * guarantee they will be delivered virtually. Some conditions (see the ISA)
    727 * cause exceptions to be delivered in real mode.
    728 *
    729 * The scv instructions are a special case. They get a 0x3000 offset applied.
    730 * scv exceptions have unique reentrancy properties, see below.
    731 *
    732 * It's impossible to receive interrupts below 0x300 via AIL.
    733 *
    734 * KVM: None of the virtual exceptions are from the guest. Anything that
    735 * escalated to HV=1 from HV=0 is delivered via real mode handlers.
    736 *
    737 *
    738 * We layout physical memory as follows:
    739 * 0x0000 - 0x00ff : Secondary processor spin code
    740 * 0x0100 - 0x18ff : Real mode pSeries interrupt vectors
    741 * 0x1900 - 0x2fff : Real mode trampolines
    742 * 0x3000 - 0x58ff : Relon (IR=1,DR=1) mode pSeries interrupt vectors
    743 * 0x5900 - 0x6fff : Relon mode trampolines
    744 * 0x7000 - 0x7fff : FWNMI data area
    745 * 0x8000 -   .... : Common interrupt handlers, remaining early
    746 *                   setup code, rest of kernel.
    747 *
    748 * We could reclaim 0x4000-0x42ff for real mode trampolines if the space
    749 * is necessary. Until then it's more consistent to explicitly put VIRT_NONE
    750 * vectors there.
    751 */
    752OPEN_FIXED_SECTION(real_vectors,        0x0100, 0x1900)
    753OPEN_FIXED_SECTION(real_trampolines,    0x1900, 0x3000)
    754OPEN_FIXED_SECTION(virt_vectors,        0x3000, 0x5900)
    755OPEN_FIXED_SECTION(virt_trampolines,    0x5900, 0x7000)
    756
    757#ifdef CONFIG_PPC_POWERNV
    758	.globl start_real_trampolines
    759	.globl end_real_trampolines
    760	.globl start_virt_trampolines
    761	.globl end_virt_trampolines
    762#endif
    763
    764#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
    765/*
    766 * Data area reserved for FWNMI option.
    767 * This address (0x7000) is fixed by the RPA.
    768 * pseries and powernv need to keep the whole page from
    769 * 0x7000 to 0x8000 free for use by the firmware
    770 */
    771ZERO_FIXED_SECTION(fwnmi_page,          0x7000, 0x8000)
    772OPEN_TEXT_SECTION(0x8000)
    773#else
    774OPEN_TEXT_SECTION(0x7000)
    775#endif
    776
    777USE_FIXED_SECTION(real_vectors)
    778
    779/*
    780 * This is the start of the interrupt handlers for pSeries
    781 * This code runs with relocation off.
    782 * Code from here to __end_interrupts gets copied down to real
    783 * address 0x100 when we are running a relocatable kernel.
    784 * Therefore any relative branches in this section must only
    785 * branch to labels in this section.
    786 */
    787	.globl __start_interrupts
    788__start_interrupts:
    789
    790/**
    791 * Interrupt 0x3000 - System Call Vectored Interrupt (syscall).
    792 * This is a synchronous interrupt invoked with the "scv" instruction. The
    793 * system call does not alter the HV bit, so it is directed to the OS.
    794 *
    795 * Handling:
    796 * scv instructions enter the kernel without changing EE, RI, ME, or HV.
    797 * In particular, this means we can take a maskable interrupt at any point
    798 * in the scv handler, which is unlike any other interrupt. This is solved
    799 * by treating the instruction addresses in the handler as being soft-masked,
    800 * by adding a SOFT_MASK_TABLE entry for them.
    801 *
    802 * AIL-0 mode scv exceptions go to 0x17000-0x17fff, but we set AIL-3 and
    803 * ensure scv is never executed with relocation off, which means AIL-0
    804 * should never happen.
    805 *
    806 * Before leaving the following inside-__end_soft_masked text, at least of the
    807 * following must be true:
    808 * - MSR[PR]=1 (i.e., return to userspace)
    809 * - MSR_EE|MSR_RI is clear (no reentrant exceptions)
    810 * - Standard kernel environment is set up (stack, paca, etc)
    811 *
    812 * KVM:
    813 * These interrupts do not elevate HV 0->1, so HV is not involved. PR KVM
    814 * ensures that FSCR[SCV] is disabled whenever it has to force AIL off.
    815 *
    816 * Call convention:
    817 *
    818 * syscall register convention is in Documentation/powerpc/syscall64-abi.rst
    819 */
    820EXC_VIRT_BEGIN(system_call_vectored, 0x3000, 0x1000)
    821	/* SCV 0 */
    822	mr	r9,r13
    823	GET_PACA(r13)
    824	mflr	r11
    825	mfctr	r12
    826	li	r10,IRQS_ALL_DISABLED
    827	stb	r10,PACAIRQSOFTMASK(r13)
    828#ifdef CONFIG_RELOCATABLE
    829	b	system_call_vectored_tramp
    830#else
    831	b	system_call_vectored_common
    832#endif
    833	nop
    834
    835	/* SCV 1 - 127 */
    836	.rept	127
    837	mr	r9,r13
    838	GET_PACA(r13)
    839	mflr	r11
    840	mfctr	r12
    841	li	r10,IRQS_ALL_DISABLED
    842	stb	r10,PACAIRQSOFTMASK(r13)
    843	li	r0,-1 /* cause failure */
    844#ifdef CONFIG_RELOCATABLE
    845	b	system_call_vectored_sigill_tramp
    846#else
    847	b	system_call_vectored_sigill
    848#endif
    849	.endr
    850EXC_VIRT_END(system_call_vectored, 0x3000, 0x1000)
    851
    852// Treat scv vectors as soft-masked, see comment above.
    853// Use absolute values rather than labels here, so they don't get relocated,
    854// because this code runs unrelocated.
    855SOFT_MASK_TABLE(0xc000000000003000, 0xc000000000004000)
    856
    857#ifdef CONFIG_RELOCATABLE
    858TRAMP_VIRT_BEGIN(system_call_vectored_tramp)
    859	__LOAD_HANDLER(r10, system_call_vectored_common, virt_trampolines)
    860	mtctr	r10
    861	bctr
    862
    863TRAMP_VIRT_BEGIN(system_call_vectored_sigill_tramp)
    864	__LOAD_HANDLER(r10, system_call_vectored_sigill, virt_trampolines)
    865	mtctr	r10
    866	bctr
    867#endif
    868
    869
    870/* No virt vectors corresponding with 0x0..0x100 */
    871EXC_VIRT_NONE(0x4000, 0x100)
    872
    873
    874/**
    875 * Interrupt 0x100 - System Reset Interrupt (SRESET aka NMI).
    876 * This is a non-maskable, asynchronous interrupt always taken in real-mode.
    877 * It is caused by:
    878 * - Wake from power-saving state, on powernv.
    879 * - An NMI from another CPU, triggered by firmware or hypercall.
    880 * - As crash/debug signal injected from BMC, firmware or hypervisor.
    881 *
    882 * Handling:
    883 * Power-save wakeup is the only performance critical path, so this is
    884 * determined quickly as possible first. In this case volatile registers
    885 * can be discarded and SPRs like CFAR don't need to be read.
    886 *
    887 * If not a powersave wakeup, then it's run as a regular interrupt, however
    888 * it uses its own stack and PACA save area to preserve the regular kernel
    889 * environment for debugging.
    890 *
    891 * This interrupt is not maskable, so triggering it when MSR[RI] is clear,
    892 * or SCRATCH0 is in use, etc. may cause a crash. It's also not entirely
    893 * correct to switch to virtual mode to run the regular interrupt handler
    894 * because it might be interrupted when the MMU is in a bad state (e.g., SLB
    895 * is clear).
    896 *
    897 * FWNMI:
    898 * PAPR specifies a "fwnmi" facility which sends the sreset to a different
    899 * entry point with a different register set up. Some hypervisors will
    900 * send the sreset to 0x100 in the guest if it is not fwnmi capable.
    901 *
    902 * KVM:
    903 * Unlike most SRR interrupts, this may be taken by the host while executing
    904 * in a guest, so a KVM test is required. KVM will pull the CPU out of guest
    905 * mode and then raise the sreset.
    906 */
    907INT_DEFINE_BEGIN(system_reset)
    908	IVEC=0x100
    909	IAREA=PACA_EXNMI
    910	IVIRT=0 /* no virt entry point */
    911	ISTACK=0
    912	IKVM_REAL=1
    913INT_DEFINE_END(system_reset)
    914
    915EXC_REAL_BEGIN(system_reset, 0x100, 0x100)
    916#ifdef CONFIG_PPC_P7_NAP
    917	/*
    918	 * If running native on arch 2.06 or later, check if we are waking up
    919	 * from nap/sleep/winkle, and branch to idle handler. This tests SRR1
    920	 * bits 46:47. A non-0 value indicates that we are coming from a power
    921	 * saving state. The idle wakeup handler initially runs in real mode,
    922	 * but we branch to the 0xc000... address so we can turn on relocation
    923	 * with mtmsrd later, after SPRs are restored.
    924	 *
    925	 * Careful to minimise cost for the fast path (idle wakeup) while
    926	 * also avoiding clobbering CFAR for the debug path (non-idle).
    927	 *
    928	 * For the idle wake case volatile registers can be clobbered, which
    929	 * is why we use those initially. If it turns out to not be an idle
    930	 * wake, carefully put everything back the way it was, so we can use
    931	 * common exception macros to handle it.
    932	 */
    933BEGIN_FTR_SECTION
    934	SET_SCRATCH0(r13)
    935	GET_PACA(r13)
    936	std	r3,PACA_EXNMI+0*8(r13)
    937	std	r4,PACA_EXNMI+1*8(r13)
    938	std	r5,PACA_EXNMI+2*8(r13)
    939	mfspr	r3,SPRN_SRR1
    940	mfocrf	r4,0x80
    941	rlwinm.	r5,r3,47-31,30,31
    942	bne+	system_reset_idle_wake
    943	/* Not powersave wakeup. Restore regs for regular interrupt handler. */
    944	mtocrf	0x80,r4
    945	ld	r3,PACA_EXNMI+0*8(r13)
    946	ld	r4,PACA_EXNMI+1*8(r13)
    947	ld	r5,PACA_EXNMI+2*8(r13)
    948	GET_SCRATCH0(r13)
    949END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
    950#endif
    951
    952	GEN_INT_ENTRY system_reset, virt=0
    953	/*
    954	 * In theory, we should not enable relocation here if it was disabled
    955	 * in SRR1, because the MMU may not be configured to support it (e.g.,
    956	 * SLB may have been cleared). In practice, there should only be a few
    957	 * small windows where that's the case, and sreset is considered to
    958	 * be dangerous anyway.
    959	 */
    960EXC_REAL_END(system_reset, 0x100, 0x100)
    961EXC_VIRT_NONE(0x4100, 0x100)
    962
    963#ifdef CONFIG_PPC_P7_NAP
    964TRAMP_REAL_BEGIN(system_reset_idle_wake)
    965	/* We are waking up from idle, so may clobber any volatile register */
    966	cmpwi	cr1,r5,2
    967	bltlr	cr1	/* no state loss, return to idle caller with r3=SRR1 */
    968	__LOAD_FAR_HANDLER(r12, DOTSYM(idle_return_gpr_loss), real_trampolines)
    969	mtctr	r12
    970	bctr
    971#endif
    972
    973#ifdef CONFIG_PPC_PSERIES
    974/*
    975 * Vectors for the FWNMI option.  Share common code.
    976 */
    977TRAMP_REAL_BEGIN(system_reset_fwnmi)
    978	GEN_INT_ENTRY system_reset, virt=0
    979
    980#endif /* CONFIG_PPC_PSERIES */
    981
    982EXC_COMMON_BEGIN(system_reset_common)
    983	__GEN_COMMON_ENTRY system_reset
    984	/*
    985	 * Increment paca->in_nmi. When the interrupt entry wrapper later
    986	 * enable MSR_RI, then SLB or MCE will be able to recover, but a nested
    987	 * NMI will notice in_nmi and not recover because of the use of the NMI
    988	 * stack. in_nmi reentrancy is tested in system_reset_exception.
    989	 */
    990	lhz	r10,PACA_IN_NMI(r13)
    991	addi	r10,r10,1
    992	sth	r10,PACA_IN_NMI(r13)
    993
    994	mr	r10,r1
    995	ld	r1,PACA_NMI_EMERG_SP(r13)
    996	subi	r1,r1,INT_FRAME_SIZE
    997	__GEN_COMMON_BODY system_reset
    998
    999	addi	r3,r1,STACK_FRAME_OVERHEAD
   1000	bl	system_reset_exception
   1001
   1002	/* Clear MSR_RI before setting SRR0 and SRR1. */
   1003	li	r9,0
   1004	mtmsrd	r9,1
   1005
   1006	/*
   1007	 * MSR_RI is clear, now we can decrement paca->in_nmi.
   1008	 */
   1009	lhz	r10,PACA_IN_NMI(r13)
   1010	subi	r10,r10,1
   1011	sth	r10,PACA_IN_NMI(r13)
   1012
   1013	kuap_kernel_restore r9, r10
   1014	EXCEPTION_RESTORE_REGS
   1015	RFI_TO_USER_OR_KERNEL
   1016
   1017
   1018/**
   1019 * Interrupt 0x200 - Machine Check Interrupt (MCE).
   1020 * This is a non-maskable interrupt always taken in real-mode. It can be
   1021 * synchronous or asynchronous, caused by hardware or software, and it may be
   1022 * taken in a power-saving state.
   1023 *
   1024 * Handling:
   1025 * Similarly to system reset, this uses its own stack and PACA save area,
   1026 * the difference is re-entrancy is allowed on the machine check stack.
   1027 *
   1028 * machine_check_early is run in real mode, and carefully decodes the
   1029 * machine check and tries to handle it (e.g., flush the SLB if there was an
   1030 * error detected there), determines if it was recoverable and logs the
   1031 * event.
   1032 *
   1033 * This early code does not "reconcile" irq soft-mask state like SRESET or
   1034 * regular interrupts do, so irqs_disabled() among other things may not work
   1035 * properly (irq disable/enable already doesn't work because irq tracing can
   1036 * not work in real mode).
   1037 *
   1038 * Then, depending on the execution context when the interrupt is taken, there
   1039 * are 3 main actions:
   1040 * - Executing in kernel mode. The event is queued with irq_work, which means
   1041 *   it is handled when it is next safe to do so (i.e., the kernel has enabled
   1042 *   interrupts), which could be immediately when the interrupt returns. This
   1043 *   avoids nasty issues like switching to virtual mode when the MMU is in a
   1044 *   bad state, or when executing OPAL code. (SRESET is exposed to such issues,
   1045 *   but it has different priorities). Check to see if the CPU was in power
   1046 *   save, and return via the wake up code if it was.
   1047 *
   1048 * - Executing in user mode. machine_check_exception is run like a normal
   1049 *   interrupt handler, which processes the data generated by the early handler.
   1050 *
   1051 * - Executing in guest mode. The interrupt is run with its KVM test, and
   1052 *   branches to KVM to deal with. KVM may queue the event for the host
   1053 *   to report later.
   1054 *
   1055 * This interrupt is not maskable, so if it triggers when MSR[RI] is clear,
   1056 * or SCRATCH0 is in use, it may cause a crash.
   1057 *
   1058 * KVM:
   1059 * See SRESET.
   1060 */
   1061INT_DEFINE_BEGIN(machine_check_early)
   1062	IVEC=0x200
   1063	IAREA=PACA_EXMC
   1064	IVIRT=0 /* no virt entry point */
   1065	IREALMODE_COMMON=1
   1066	ISTACK=0
   1067	IDAR=1
   1068	IDSISR=1
   1069	IKUAP=0 /* We don't touch AMR here, we never go to virtual mode */
   1070INT_DEFINE_END(machine_check_early)
   1071
   1072INT_DEFINE_BEGIN(machine_check)
   1073	IVEC=0x200
   1074	IAREA=PACA_EXMC
   1075	IVIRT=0 /* no virt entry point */
   1076	IDAR=1
   1077	IDSISR=1
   1078	IKVM_REAL=1
   1079INT_DEFINE_END(machine_check)
   1080
   1081EXC_REAL_BEGIN(machine_check, 0x200, 0x100)
   1082	GEN_INT_ENTRY machine_check_early, virt=0
   1083EXC_REAL_END(machine_check, 0x200, 0x100)
   1084EXC_VIRT_NONE(0x4200, 0x100)
   1085
   1086#ifdef CONFIG_PPC_PSERIES
   1087TRAMP_REAL_BEGIN(machine_check_fwnmi)
   1088	/* See comment at machine_check exception, don't turn on RI */
   1089	GEN_INT_ENTRY machine_check_early, virt=0
   1090#endif
   1091
   1092#define MACHINE_CHECK_HANDLER_WINDUP			\
   1093	/* Clear MSR_RI before setting SRR0 and SRR1. */\
   1094	li	r9,0;					\
   1095	mtmsrd	r9,1;		/* Clear MSR_RI */	\
   1096	/* Decrement paca->in_mce now RI is clear. */	\
   1097	lhz	r12,PACA_IN_MCE(r13);			\
   1098	subi	r12,r12,1;				\
   1099	sth	r12,PACA_IN_MCE(r13);			\
   1100	EXCEPTION_RESTORE_REGS
   1101
   1102EXC_COMMON_BEGIN(machine_check_early_common)
   1103	__GEN_REALMODE_COMMON_ENTRY machine_check_early
   1104
   1105	/*
   1106	 * Switch to mc_emergency stack and handle re-entrancy (we limit
   1107	 * the nested MCE upto level 4 to avoid stack overflow).
   1108	 * Save MCE registers srr1, srr0, dar and dsisr and then set ME=1
   1109	 *
   1110	 * We use paca->in_mce to check whether this is the first entry or
   1111	 * nested machine check. We increment paca->in_mce to track nested
   1112	 * machine checks.
   1113	 *
   1114	 * If this is the first entry then set stack pointer to
   1115	 * paca->mc_emergency_sp, otherwise r1 is already pointing to
   1116	 * stack frame on mc_emergency stack.
   1117	 *
   1118	 * NOTE: We are here with MSR_ME=0 (off), which means we risk a
   1119	 * checkstop if we get another machine check exception before we do
   1120	 * rfid with MSR_ME=1.
   1121	 *
   1122	 * This interrupt can wake directly from idle. If that is the case,
   1123	 * the machine check is handled then the idle wakeup code is called
   1124	 * to restore state.
   1125	 */
   1126	lhz	r10,PACA_IN_MCE(r13)
   1127	cmpwi	r10,0			/* Are we in nested machine check */
   1128	cmpwi	cr1,r10,MAX_MCE_DEPTH	/* Are we at maximum nesting */
   1129	addi	r10,r10,1		/* increment paca->in_mce */
   1130	sth	r10,PACA_IN_MCE(r13)
   1131
   1132	mr	r10,r1			/* Save r1 */
   1133	bne	1f
   1134	/* First machine check entry */
   1135	ld	r1,PACAMCEMERGSP(r13)	/* Use MC emergency stack */
   11361:	/* Limit nested MCE to level 4 to avoid stack overflow */
   1137	bgt	cr1,unrecoverable_mce	/* Check if we hit limit of 4 */
   1138	subi	r1,r1,INT_FRAME_SIZE	/* alloc stack frame */
   1139
   1140	__GEN_COMMON_BODY machine_check_early
   1141
   1142BEGIN_FTR_SECTION
   1143	bl	enable_machine_check
   1144END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
   1145	addi	r3,r1,STACK_FRAME_OVERHEAD
   1146	bl	machine_check_early
   1147	std	r3,RESULT(r1)	/* Save result */
   1148	ld	r12,_MSR(r1)
   1149
   1150#ifdef CONFIG_PPC_P7_NAP
   1151	/*
   1152	 * Check if thread was in power saving mode. We come here when any
   1153	 * of the following is true:
   1154	 * a. thread wasn't in power saving mode
   1155	 * b. thread was in power saving mode with no state loss,
   1156	 *    supervisor state loss or hypervisor state loss.
   1157	 *
   1158	 * Go back to nap/sleep/winkle mode again if (b) is true.
   1159	 */
   1160BEGIN_FTR_SECTION
   1161	rlwinm.	r11,r12,47-31,30,31
   1162	bne	machine_check_idle_common
   1163END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
   1164#endif
   1165
   1166#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
   1167	/*
   1168	 * Check if we are coming from guest. If yes, then run the normal
   1169	 * exception handler which will take the
   1170	 * machine_check_kvm->kvm_interrupt branch to deliver the MC event
   1171	 * to guest.
   1172	 */
   1173	lbz	r11,HSTATE_IN_GUEST(r13)
   1174	cmpwi	r11,0			/* Check if coming from guest */
   1175	bne	mce_deliver		/* continue if we are. */
   1176#endif
   1177
   1178	/*
   1179	 * Check if we are coming from userspace. If yes, then run the normal
   1180	 * exception handler which will deliver the MC event to this kernel.
   1181	 */
   1182	andi.	r11,r12,MSR_PR		/* See if coming from user. */
   1183	bne	mce_deliver		/* continue in V mode if we are. */
   1184
   1185	/*
   1186	 * At this point we are coming from kernel context.
   1187	 * Queue up the MCE event and return from the interrupt.
   1188	 * But before that, check if this is an un-recoverable exception.
   1189	 * If yes, then stay on emergency stack and panic.
   1190	 */
   1191	andi.	r11,r12,MSR_RI
   1192	beq	unrecoverable_mce
   1193
   1194	/*
   1195	 * Check if we have successfully handled/recovered from error, if not
   1196	 * then stay on emergency stack and panic.
   1197	 */
   1198	ld	r3,RESULT(r1)	/* Load result */
   1199	cmpdi	r3,0		/* see if we handled MCE successfully */
   1200	beq	unrecoverable_mce /* if !handled then panic */
   1201
   1202	/*
   1203	 * Return from MC interrupt.
   1204	 * Queue up the MCE event so that we can log it later, while
   1205	 * returning from kernel or opal call.
   1206	 */
   1207	bl	machine_check_queue_event
   1208	MACHINE_CHECK_HANDLER_WINDUP
   1209	RFI_TO_KERNEL
   1210
   1211mce_deliver:
   1212	/*
   1213	 * This is a host user or guest MCE. Restore all registers, then
   1214	 * run the "late" handler. For host user, this will run the
   1215	 * machine_check_exception handler in virtual mode like a normal
   1216	 * interrupt handler. For guest, this will trigger the KVM test
   1217	 * and branch to the KVM interrupt similarly to other interrupts.
   1218	 */
   1219BEGIN_FTR_SECTION
   1220	ld	r10,ORIG_GPR3(r1)
   1221	mtspr	SPRN_CFAR,r10
   1222END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
   1223	MACHINE_CHECK_HANDLER_WINDUP
   1224	GEN_INT_ENTRY machine_check, virt=0
   1225
   1226EXC_COMMON_BEGIN(machine_check_common)
   1227	/*
   1228	 * Machine check is different because we use a different
   1229	 * save area: PACA_EXMC instead of PACA_EXGEN.
   1230	 */
   1231	GEN_COMMON machine_check
   1232	addi	r3,r1,STACK_FRAME_OVERHEAD
   1233	bl	machine_check_exception_async
   1234	b	interrupt_return_srr
   1235
   1236
   1237#ifdef CONFIG_PPC_P7_NAP
   1238/*
   1239 * This is an idle wakeup. Low level machine check has already been
   1240 * done. Queue the event then call the idle code to do the wake up.
   1241 */
   1242EXC_COMMON_BEGIN(machine_check_idle_common)
   1243	bl	machine_check_queue_event
   1244
   1245	/*
   1246	 * GPR-loss wakeups are relatively straightforward, because the
   1247	 * idle sleep code has saved all non-volatile registers on its
   1248	 * own stack, and r1 in PACAR1.
   1249	 *
   1250	 * For no-loss wakeups the r1 and lr registers used by the
   1251	 * early machine check handler have to be restored first. r2 is
   1252	 * the kernel TOC, so no need to restore it.
   1253	 *
   1254	 * Then decrement MCE nesting after finishing with the stack.
   1255	 */
   1256	ld	r3,_MSR(r1)
   1257	ld	r4,_LINK(r1)
   1258	ld	r1,GPR1(r1)
   1259
   1260	lhz	r11,PACA_IN_MCE(r13)
   1261	subi	r11,r11,1
   1262	sth	r11,PACA_IN_MCE(r13)
   1263
   1264	mtlr	r4
   1265	rlwinm	r10,r3,47-31,30,31
   1266	cmpwi	cr1,r10,2
   1267	bltlr	cr1	/* no state loss, return to idle caller with r3=SRR1 */
   1268	b	idle_return_gpr_loss
   1269#endif
   1270
   1271EXC_COMMON_BEGIN(unrecoverable_mce)
   1272	/*
   1273	 * We are going down. But there are chances that we might get hit by
   1274	 * another MCE during panic path and we may run into unstable state
   1275	 * with no way out. Hence, turn ME bit off while going down, so that
   1276	 * when another MCE is hit during panic path, system will checkstop
   1277	 * and hypervisor will get restarted cleanly by SP.
   1278	 */
   1279BEGIN_FTR_SECTION
   1280	li	r10,0 /* clear MSR_RI */
   1281	mtmsrd	r10,1
   1282	bl	disable_machine_check
   1283END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
   1284	ld	r10,PACAKMSR(r13)
   1285	li	r3,MSR_ME
   1286	andc	r10,r10,r3
   1287	mtmsrd	r10
   1288
   1289	lhz	r12,PACA_IN_MCE(r13)
   1290	subi	r12,r12,1
   1291	sth	r12,PACA_IN_MCE(r13)
   1292
   1293	/*
   1294	 * Invoke machine_check_exception to print MCE event and panic.
   1295	 * This is the NMI version of the handler because we are called from
   1296	 * the early handler which is a true NMI.
   1297	 */
   1298	addi	r3,r1,STACK_FRAME_OVERHEAD
   1299	bl	machine_check_exception
   1300
   1301	/*
   1302	 * We will not reach here. Even if we did, there is no way out.
   1303	 * Call unrecoverable_exception and die.
   1304	 */
   1305	addi	r3,r1,STACK_FRAME_OVERHEAD
   1306	bl	unrecoverable_exception
   1307	b	.
   1308
   1309
   1310/**
   1311 * Interrupt 0x300 - Data Storage Interrupt (DSI).
   1312 * This is a synchronous interrupt generated due to a data access exception,
   1313 * e.g., a load orstore which does not have a valid page table entry with
   1314 * permissions. DAWR matches also fault here, as do RC updates, and minor misc
   1315 * errors e.g., copy/paste, AMO, certain invalid CI accesses, etc.
   1316 *
   1317 * Handling:
   1318 * - Hash MMU
   1319 *   Go to do_hash_fault, which attempts to fill the HPT from an entry in the
   1320 *   Linux page table. Hash faults can hit in kernel mode in a fairly
   1321 *   arbitrary state (e.g., interrupts disabled, locks held) when accessing
   1322 *   "non-bolted" regions, e.g., vmalloc space. However these should always be
   1323 *   backed by Linux page table entries.
   1324 *
   1325 *   If no entry is found the Linux page fault handler is invoked (by
   1326 *   do_hash_fault). Linux page faults can happen in kernel mode due to user
   1327 *   copy operations of course.
   1328 *
   1329 *   KVM: The KVM HDSI handler may perform a load with MSR[DR]=1 in guest
   1330 *   MMU context, which may cause a DSI in the host, which must go to the
   1331 *   KVM handler. MSR[IR] is not enabled, so the real-mode handler will
   1332 *   always be used regardless of AIL setting.
   1333 *
   1334 * - Radix MMU
   1335 *   The hardware loads from the Linux page table directly, so a fault goes
   1336 *   immediately to Linux page fault.
   1337 *
   1338 * Conditions like DAWR match are handled on the way in to Linux page fault.
   1339 */
   1340INT_DEFINE_BEGIN(data_access)
   1341	IVEC=0x300
   1342	IDAR=1
   1343	IDSISR=1
   1344	IKVM_REAL=1
   1345INT_DEFINE_END(data_access)
   1346
   1347EXC_REAL_BEGIN(data_access, 0x300, 0x80)
   1348	GEN_INT_ENTRY data_access, virt=0
   1349EXC_REAL_END(data_access, 0x300, 0x80)
   1350EXC_VIRT_BEGIN(data_access, 0x4300, 0x80)
   1351	GEN_INT_ENTRY data_access, virt=1
   1352EXC_VIRT_END(data_access, 0x4300, 0x80)
   1353EXC_COMMON_BEGIN(data_access_common)
   1354	GEN_COMMON data_access
   1355	ld	r4,_DSISR(r1)
   1356	addi	r3,r1,STACK_FRAME_OVERHEAD
   1357	andis.	r0,r4,DSISR_DABRMATCH@h
   1358	bne-	1f
   1359#ifdef CONFIG_PPC_64S_HASH_MMU
   1360BEGIN_MMU_FTR_SECTION
   1361	bl	do_hash_fault
   1362MMU_FTR_SECTION_ELSE
   1363	bl	do_page_fault
   1364ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
   1365#else
   1366	bl	do_page_fault
   1367#endif
   1368	b	interrupt_return_srr
   1369
   13701:	bl	do_break
   1371	/*
   1372	 * do_break() may have changed the NV GPRS while handling a breakpoint.
   1373	 * If so, we need to restore them with their updated values.
   1374	 */
   1375	REST_NVGPRS(r1)
   1376	b	interrupt_return_srr
   1377
   1378
   1379/**
   1380 * Interrupt 0x380 - Data Segment Interrupt (DSLB).
   1381 * This is a synchronous interrupt in response to an MMU fault missing SLB
   1382 * entry for HPT, or an address outside RPT translation range.
   1383 *
   1384 * Handling:
   1385 * - HPT:
   1386 *   This refills the SLB, or reports an access fault similarly to a bad page
   1387 *   fault. When coming from user-mode, the SLB handler may access any kernel
   1388 *   data, though it may itself take a DSLB. When coming from kernel mode,
   1389 *   recursive faults must be avoided so access is restricted to the kernel
   1390 *   image text/data, kernel stack, and any data allocated below
   1391 *   ppc64_bolted_size (first segment). The kernel handler must avoid stomping
   1392 *   on user-handler data structures.
   1393 *
   1394 *   KVM: Same as 0x300, DSLB must test for KVM guest.
   1395 */
   1396INT_DEFINE_BEGIN(data_access_slb)
   1397	IVEC=0x380
   1398	IDAR=1
   1399	IKVM_REAL=1
   1400INT_DEFINE_END(data_access_slb)
   1401
   1402EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)
   1403	GEN_INT_ENTRY data_access_slb, virt=0
   1404EXC_REAL_END(data_access_slb, 0x380, 0x80)
   1405EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
   1406	GEN_INT_ENTRY data_access_slb, virt=1
   1407EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
   1408EXC_COMMON_BEGIN(data_access_slb_common)
   1409	GEN_COMMON data_access_slb
   1410#ifdef CONFIG_PPC_64S_HASH_MMU
   1411BEGIN_MMU_FTR_SECTION
   1412	/* HPT case, do SLB fault */
   1413	addi	r3,r1,STACK_FRAME_OVERHEAD
   1414	bl	do_slb_fault
   1415	cmpdi	r3,0
   1416	bne-	1f
   1417	b	fast_interrupt_return_srr
   14181:	/* Error case */
   1419MMU_FTR_SECTION_ELSE
   1420	/* Radix case, access is outside page table range */
   1421	li	r3,-EFAULT
   1422ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
   1423#else
   1424	li	r3,-EFAULT
   1425#endif
   1426	std	r3,RESULT(r1)
   1427	addi	r3,r1,STACK_FRAME_OVERHEAD
   1428	bl	do_bad_segment_interrupt
   1429	b	interrupt_return_srr
   1430
   1431
   1432/**
   1433 * Interrupt 0x400 - Instruction Storage Interrupt (ISI).
   1434 * This is a synchronous interrupt in response to an MMU fault due to an
   1435 * instruction fetch.
   1436 *
   1437 * Handling:
   1438 * Similar to DSI, though in response to fetch. The faulting address is found
   1439 * in SRR0 (rather than DAR), and status in SRR1 (rather than DSISR).
   1440 */
   1441INT_DEFINE_BEGIN(instruction_access)
   1442	IVEC=0x400
   1443	IISIDE=1
   1444	IDAR=1
   1445	IDSISR=1
   1446#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   1447	IKVM_REAL=1
   1448#endif
   1449INT_DEFINE_END(instruction_access)
   1450
   1451EXC_REAL_BEGIN(instruction_access, 0x400, 0x80)
   1452	GEN_INT_ENTRY instruction_access, virt=0
   1453EXC_REAL_END(instruction_access, 0x400, 0x80)
   1454EXC_VIRT_BEGIN(instruction_access, 0x4400, 0x80)
   1455	GEN_INT_ENTRY instruction_access, virt=1
   1456EXC_VIRT_END(instruction_access, 0x4400, 0x80)
   1457EXC_COMMON_BEGIN(instruction_access_common)
   1458	GEN_COMMON instruction_access
   1459	addi	r3,r1,STACK_FRAME_OVERHEAD
   1460#ifdef CONFIG_PPC_64S_HASH_MMU
   1461BEGIN_MMU_FTR_SECTION
   1462	bl	do_hash_fault
   1463MMU_FTR_SECTION_ELSE
   1464	bl	do_page_fault
   1465ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
   1466#else
   1467	bl	do_page_fault
   1468#endif
   1469	b	interrupt_return_srr
   1470
   1471
   1472/**
   1473 * Interrupt 0x480 - Instruction Segment Interrupt (ISLB).
   1474 * This is a synchronous interrupt in response to an MMU fault due to an
   1475 * instruction fetch.
   1476 *
   1477 * Handling:
   1478 * Similar to DSLB, though in response to fetch. The faulting address is found
   1479 * in SRR0 (rather than DAR).
   1480 */
   1481INT_DEFINE_BEGIN(instruction_access_slb)
   1482	IVEC=0x480
   1483	IISIDE=1
   1484	IDAR=1
   1485#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   1486	IKVM_REAL=1
   1487#endif
   1488INT_DEFINE_END(instruction_access_slb)
   1489
   1490EXC_REAL_BEGIN(instruction_access_slb, 0x480, 0x80)
   1491	GEN_INT_ENTRY instruction_access_slb, virt=0
   1492EXC_REAL_END(instruction_access_slb, 0x480, 0x80)
   1493EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
   1494	GEN_INT_ENTRY instruction_access_slb, virt=1
   1495EXC_VIRT_END(instruction_access_slb, 0x4480, 0x80)
   1496EXC_COMMON_BEGIN(instruction_access_slb_common)
   1497	GEN_COMMON instruction_access_slb
   1498#ifdef CONFIG_PPC_64S_HASH_MMU
   1499BEGIN_MMU_FTR_SECTION
   1500	/* HPT case, do SLB fault */
   1501	addi	r3,r1,STACK_FRAME_OVERHEAD
   1502	bl	do_slb_fault
   1503	cmpdi	r3,0
   1504	bne-	1f
   1505	b	fast_interrupt_return_srr
   15061:	/* Error case */
   1507MMU_FTR_SECTION_ELSE
   1508	/* Radix case, access is outside page table range */
   1509	li	r3,-EFAULT
   1510ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
   1511#else
   1512	li	r3,-EFAULT
   1513#endif
   1514	std	r3,RESULT(r1)
   1515	addi	r3,r1,STACK_FRAME_OVERHEAD
   1516	bl	do_bad_segment_interrupt
   1517	b	interrupt_return_srr
   1518
   1519
   1520/**
   1521 * Interrupt 0x500 - External Interrupt.
   1522 * This is an asynchronous maskable interrupt in response to an "external
   1523 * exception" from the interrupt controller or hypervisor (e.g., device
   1524 * interrupt). It is maskable in hardware by clearing MSR[EE], and
   1525 * soft-maskable with IRQS_DISABLED mask (i.e., local_irq_disable()).
   1526 *
   1527 * When running in HV mode, Linux sets up the LPCR[LPES] bit such that
   1528 * interrupts are delivered with HSRR registers, guests use SRRs, which
   1529 * reqiures IHSRR_IF_HVMODE.
   1530 *
   1531 * On bare metal POWER9 and later, Linux sets the LPCR[HVICE] bit such that
   1532 * external interrupts are delivered as Hypervisor Virtualization Interrupts
   1533 * rather than External Interrupts.
   1534 *
   1535 * Handling:
   1536 * This calls into Linux IRQ handler. NVGPRs are not saved to reduce overhead,
   1537 * because registers at the time of the interrupt are not so important as it is
   1538 * asynchronous.
   1539 *
   1540 * If soft masked, the masked handler will note the pending interrupt for
   1541 * replay, and clear MSR[EE] in the interrupted context.
   1542 *
   1543 * CFAR is not required because this is an asynchronous interrupt that in
   1544 * general won't have much bearing on the state of the CPU, with the possible
   1545 * exception of crash/debug IPIs, but those are generally moving to use SRESET
   1546 * IPIs. Unless this is an HV interrupt and KVM HV is possible, in which case
   1547 * it may be exiting the guest and need CFAR to be saved.
   1548 */
   1549INT_DEFINE_BEGIN(hardware_interrupt)
   1550	IVEC=0x500
   1551	IHSRR_IF_HVMODE=1
   1552	IMASK=IRQS_DISABLED
   1553	IKVM_REAL=1
   1554	IKVM_VIRT=1
   1555	ICFAR=0
   1556#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
   1557	ICFAR_IF_HVMODE=1
   1558#endif
   1559INT_DEFINE_END(hardware_interrupt)
   1560
   1561EXC_REAL_BEGIN(hardware_interrupt, 0x500, 0x100)
   1562	GEN_INT_ENTRY hardware_interrupt, virt=0
   1563EXC_REAL_END(hardware_interrupt, 0x500, 0x100)
   1564EXC_VIRT_BEGIN(hardware_interrupt, 0x4500, 0x100)
   1565	GEN_INT_ENTRY hardware_interrupt, virt=1
   1566EXC_VIRT_END(hardware_interrupt, 0x4500, 0x100)
   1567EXC_COMMON_BEGIN(hardware_interrupt_common)
   1568	GEN_COMMON hardware_interrupt
   1569	addi	r3,r1,STACK_FRAME_OVERHEAD
   1570	bl	do_IRQ
   1571	BEGIN_FTR_SECTION
   1572	b	interrupt_return_hsrr
   1573	FTR_SECTION_ELSE
   1574	b	interrupt_return_srr
   1575	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
   1576
   1577
   1578/**
   1579 * Interrupt 0x600 - Alignment Interrupt
   1580 * This is a synchronous interrupt in response to data alignment fault.
   1581 */
   1582INT_DEFINE_BEGIN(alignment)
   1583	IVEC=0x600
   1584	IDAR=1
   1585	IDSISR=1
   1586#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   1587	IKVM_REAL=1
   1588#endif
   1589INT_DEFINE_END(alignment)
   1590
   1591EXC_REAL_BEGIN(alignment, 0x600, 0x100)
   1592	GEN_INT_ENTRY alignment, virt=0
   1593EXC_REAL_END(alignment, 0x600, 0x100)
   1594EXC_VIRT_BEGIN(alignment, 0x4600, 0x100)
   1595	GEN_INT_ENTRY alignment, virt=1
   1596EXC_VIRT_END(alignment, 0x4600, 0x100)
   1597EXC_COMMON_BEGIN(alignment_common)
   1598	GEN_COMMON alignment
   1599	addi	r3,r1,STACK_FRAME_OVERHEAD
   1600	bl	alignment_exception
   1601	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
   1602	b	interrupt_return_srr
   1603
   1604
   1605/**
   1606 * Interrupt 0x700 - Program Interrupt (program check).
   1607 * This is a synchronous interrupt in response to various instruction faults:
   1608 * traps, privilege errors, TM errors, floating point exceptions.
   1609 *
   1610 * Handling:
   1611 * This interrupt may use the "emergency stack" in some cases when being taken
   1612 * from kernel context, which complicates handling.
   1613 */
   1614INT_DEFINE_BEGIN(program_check)
   1615	IVEC=0x700
   1616#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   1617	IKVM_REAL=1
   1618#endif
   1619INT_DEFINE_END(program_check)
   1620
   1621EXC_REAL_BEGIN(program_check, 0x700, 0x100)
   1622
   1623#ifdef CONFIG_CPU_LITTLE_ENDIAN
   1624	/*
   1625	 * There's a short window during boot where although the kernel is
   1626	 * running little endian, any exceptions will cause the CPU to switch
   1627	 * back to big endian. For example a WARN() boils down to a trap
   1628	 * instruction, which will cause a program check, and we end up here but
   1629	 * with the CPU in big endian mode. The first instruction of the program
   1630	 * check handler (in GEN_INT_ENTRY below) is an mtsprg, which when
   1631	 * executed in the wrong endian is an lhzu with a ~3GB displacement from
   1632	 * r3. The content of r3 is random, so that is a load from some random
   1633	 * location, and depending on the system can easily lead to a checkstop,
   1634	 * or an infinitely recursive page fault.
   1635	 *
   1636	 * So to handle that case we have a trampoline here that can detect we
   1637	 * are in the wrong endian and flip us back to the correct endian. We
   1638	 * can't flip MSR[LE] using mtmsr, so we have to use rfid. That requires
   1639	 * backing up SRR0/1 as well as a GPR. To do that we use SPRG0/2/3, as
   1640	 * SPRG1 is already used for the paca. SPRG3 is user readable, but this
   1641	 * trampoline is only active very early in boot, and SPRG3 will be
   1642	 * reinitialised in vdso_getcpu_init() before userspace starts.
   1643	 */
   1644BEGIN_FTR_SECTION
   1645	tdi   0,0,0x48    // Trap never, or in reverse endian: b . + 8
   1646	b     1f          // Skip trampoline if endian is correct
   1647	.long 0xa643707d  // mtsprg  0, r11      Backup r11
   1648	.long 0xa6027a7d  // mfsrr0  r11
   1649	.long 0xa643727d  // mtsprg  2, r11      Backup SRR0 in SPRG2
   1650	.long 0xa6027b7d  // mfsrr1  r11
   1651	.long 0xa643737d  // mtsprg  3, r11      Backup SRR1 in SPRG3
   1652	.long 0xa600607d  // mfmsr   r11
   1653	.long 0x01006b69  // xori    r11, r11, 1 Invert MSR[LE]
   1654	.long 0xa6037b7d  // mtsrr1  r11
   1655	.long 0x34076039  // li      r11, 0x734
   1656	.long 0xa6037a7d  // mtsrr0  r11
   1657	.long 0x2400004c  // rfid
   1658	mfsprg r11, 3
   1659	mtsrr1 r11        // Restore SRR1
   1660	mfsprg r11, 2
   1661	mtsrr0 r11        // Restore SRR0
   1662	mfsprg r11, 0     // Restore r11
   16631:
   1664END_FTR_SECTION(0, 1)     // nop out after boot
   1665#endif /* CONFIG_CPU_LITTLE_ENDIAN */
   1666
   1667	GEN_INT_ENTRY program_check, virt=0
   1668EXC_REAL_END(program_check, 0x700, 0x100)
   1669EXC_VIRT_BEGIN(program_check, 0x4700, 0x100)
   1670	GEN_INT_ENTRY program_check, virt=1
   1671EXC_VIRT_END(program_check, 0x4700, 0x100)
   1672EXC_COMMON_BEGIN(program_check_common)
   1673	__GEN_COMMON_ENTRY program_check
   1674
   1675	/*
   1676	 * It's possible to receive a TM Bad Thing type program check with
   1677	 * userspace register values (in particular r1), but with SRR1 reporting
   1678	 * that we came from the kernel. Normally that would confuse the bad
   1679	 * stack logic, and we would report a bad kernel stack pointer. Instead
   1680	 * we switch to the emergency stack if we're taking a TM Bad Thing from
   1681	 * the kernel.
   1682	 */
   1683
   1684	andi.	r10,r12,MSR_PR
   1685	bne	.Lnormal_stack		/* If userspace, go normal path */
   1686
   1687	andis.	r10,r12,(SRR1_PROGTM)@h
   1688	bne	.Lemergency_stack	/* If TM, emergency		*/
   1689
   1690	cmpdi	r1,-INT_FRAME_SIZE	/* check if r1 is in userspace	*/
   1691	blt	.Lnormal_stack		/* normal path if not		*/
   1692
   1693	/* Use the emergency stack					*/
   1694.Lemergency_stack:
   1695	andi.	r10,r12,MSR_PR		/* Set CR0 correctly for label	*/
   1696					/* 3 in EXCEPTION_PROLOG_COMMON	*/
   1697	mr	r10,r1			/* Save r1			*/
   1698	ld	r1,PACAEMERGSP(r13)	/* Use emergency stack		*/
   1699	subi	r1,r1,INT_FRAME_SIZE	/* alloc stack frame		*/
   1700	__ISTACK(program_check)=0
   1701	__GEN_COMMON_BODY program_check
   1702	b .Ldo_program_check
   1703
   1704.Lnormal_stack:
   1705	__ISTACK(program_check)=1
   1706	__GEN_COMMON_BODY program_check
   1707
   1708.Ldo_program_check:
   1709	addi	r3,r1,STACK_FRAME_OVERHEAD
   1710	bl	program_check_exception
   1711	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
   1712	b	interrupt_return_srr
   1713
   1714
   1715/*
   1716 * Interrupt 0x800 - Floating-Point Unavailable Interrupt.
   1717 * This is a synchronous interrupt in response to executing an fp instruction
   1718 * with MSR[FP]=0.
   1719 *
   1720 * Handling:
   1721 * This will load FP registers and enable the FP bit if coming from userspace,
   1722 * otherwise report a bad kernel use of FP.
   1723 */
   1724INT_DEFINE_BEGIN(fp_unavailable)
   1725	IVEC=0x800
   1726#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   1727	IKVM_REAL=1
   1728#endif
   1729INT_DEFINE_END(fp_unavailable)
   1730
   1731EXC_REAL_BEGIN(fp_unavailable, 0x800, 0x100)
   1732	GEN_INT_ENTRY fp_unavailable, virt=0
   1733EXC_REAL_END(fp_unavailable, 0x800, 0x100)
   1734EXC_VIRT_BEGIN(fp_unavailable, 0x4800, 0x100)
   1735	GEN_INT_ENTRY fp_unavailable, virt=1
   1736EXC_VIRT_END(fp_unavailable, 0x4800, 0x100)
   1737EXC_COMMON_BEGIN(fp_unavailable_common)
   1738	GEN_COMMON fp_unavailable
   1739	bne	1f			/* if from user, just load it up */
   1740	addi	r3,r1,STACK_FRAME_OVERHEAD
   1741	bl	kernel_fp_unavailable_exception
   17420:	trap
   1743	EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
   17441:
   1745#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
   1746BEGIN_FTR_SECTION
   1747	/* Test if 2 TM state bits are zero.  If non-zero (ie. userspace was in
   1748	 * transaction), go do TM stuff
   1749	 */
   1750	rldicl.	r0, r12, (64-MSR_TS_LG), (64-2)
   1751	bne-	2f
   1752END_FTR_SECTION_IFSET(CPU_FTR_TM)
   1753#endif
   1754	bl	load_up_fpu
   1755	b	fast_interrupt_return_srr
   1756#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
   17572:	/* User process was in a transaction */
   1758	addi	r3,r1,STACK_FRAME_OVERHEAD
   1759	bl	fp_unavailable_tm
   1760	b	interrupt_return_srr
   1761#endif
   1762
   1763
   1764/**
   1765 * Interrupt 0x900 - Decrementer Interrupt.
   1766 * This is an asynchronous interrupt in response to a decrementer exception
   1767 * (e.g., DEC has wrapped below zero). It is maskable in hardware by clearing
   1768 * MSR[EE], and soft-maskable with IRQS_DISABLED mask (i.e.,
   1769 * local_irq_disable()).
   1770 *
   1771 * Handling:
   1772 * This calls into Linux timer handler. NVGPRs are not saved (see 0x500).
   1773 *
   1774 * If soft masked, the masked handler will note the pending interrupt for
   1775 * replay, and bump the decrementer to a high value, leaving MSR[EE] enabled
   1776 * in the interrupted context.
   1777 * If PPC_WATCHDOG is configured, the soft masked handler will actually set
   1778 * things back up to run soft_nmi_interrupt as a regular interrupt handler
   1779 * on the emergency stack.
   1780 *
   1781 * CFAR is not required because this is asynchronous (see hardware_interrupt).
   1782 * A watchdog interrupt may like to have CFAR, but usually the interesting
   1783 * branch is long gone by that point (e.g., infinite loop).
   1784 */
   1785INT_DEFINE_BEGIN(decrementer)
   1786	IVEC=0x900
   1787	IMASK=IRQS_DISABLED
   1788#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   1789	IKVM_REAL=1
   1790#endif
   1791	ICFAR=0
   1792INT_DEFINE_END(decrementer)
   1793
   1794EXC_REAL_BEGIN(decrementer, 0x900, 0x80)
   1795	GEN_INT_ENTRY decrementer, virt=0
   1796EXC_REAL_END(decrementer, 0x900, 0x80)
   1797EXC_VIRT_BEGIN(decrementer, 0x4900, 0x80)
   1798	GEN_INT_ENTRY decrementer, virt=1
   1799EXC_VIRT_END(decrementer, 0x4900, 0x80)
   1800EXC_COMMON_BEGIN(decrementer_common)
   1801	GEN_COMMON decrementer
   1802	addi	r3,r1,STACK_FRAME_OVERHEAD
   1803	bl	timer_interrupt
   1804	b	interrupt_return_srr
   1805
   1806
   1807/**
   1808 * Interrupt 0x980 - Hypervisor Decrementer Interrupt.
   1809 * This is an asynchronous interrupt, similar to 0x900 but for the HDEC
   1810 * register.
   1811 *
   1812 * Handling:
   1813 * Linux does not use this outside KVM where it's used to keep a host timer
   1814 * while the guest is given control of DEC. It should normally be caught by
   1815 * the KVM test and routed there.
   1816 */
   1817INT_DEFINE_BEGIN(hdecrementer)
   1818	IVEC=0x980
   1819	IHSRR=1
   1820	ISTACK=0
   1821	IKVM_REAL=1
   1822	IKVM_VIRT=1
   1823INT_DEFINE_END(hdecrementer)
   1824
   1825EXC_REAL_BEGIN(hdecrementer, 0x980, 0x80)
   1826	GEN_INT_ENTRY hdecrementer, virt=0
   1827EXC_REAL_END(hdecrementer, 0x980, 0x80)
   1828EXC_VIRT_BEGIN(hdecrementer, 0x4980, 0x80)
   1829	GEN_INT_ENTRY hdecrementer, virt=1
   1830EXC_VIRT_END(hdecrementer, 0x4980, 0x80)
   1831EXC_COMMON_BEGIN(hdecrementer_common)
   1832	__GEN_COMMON_ENTRY hdecrementer
   1833	/*
   1834	 * Hypervisor decrementer interrupts not caught by the KVM test
   1835	 * shouldn't occur but are sometimes left pending on exit from a KVM
   1836	 * guest.  We don't need to do anything to clear them, as they are
   1837	 * edge-triggered.
   1838	 *
   1839	 * Be careful to avoid touching the kernel stack.
   1840	 */
   1841	li	r10,0
   1842	stb	r10,PACAHSRR_VALID(r13)
   1843	ld	r10,PACA_EXGEN+EX_CTR(r13)
   1844	mtctr	r10
   1845	mtcrf	0x80,r9
   1846	ld	r9,PACA_EXGEN+EX_R9(r13)
   1847	ld	r10,PACA_EXGEN+EX_R10(r13)
   1848	ld	r11,PACA_EXGEN+EX_R11(r13)
   1849	ld	r12,PACA_EXGEN+EX_R12(r13)
   1850	ld	r13,PACA_EXGEN+EX_R13(r13)
   1851	HRFI_TO_KERNEL
   1852
   1853
   1854/**
   1855 * Interrupt 0xa00 - Directed Privileged Doorbell Interrupt.
   1856 * This is an asynchronous interrupt in response to a msgsndp doorbell.
   1857 * It is maskable in hardware by clearing MSR[EE], and soft-maskable with
   1858 * IRQS_DISABLED mask (i.e., local_irq_disable()).
   1859 *
   1860 * Handling:
   1861 * Guests may use this for IPIs between threads in a core if the
   1862 * hypervisor supports it. NVGPRS are not saved (see 0x500).
   1863 *
   1864 * If soft masked, the masked handler will note the pending interrupt for
   1865 * replay, leaving MSR[EE] enabled in the interrupted context because the
   1866 * doorbells are edge triggered.
   1867 *
   1868 * CFAR is not required, similarly to hardware_interrupt.
   1869 */
   1870INT_DEFINE_BEGIN(doorbell_super)
   1871	IVEC=0xa00
   1872	IMASK=IRQS_DISABLED
   1873#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   1874	IKVM_REAL=1
   1875#endif
   1876	ICFAR=0
   1877INT_DEFINE_END(doorbell_super)
   1878
   1879EXC_REAL_BEGIN(doorbell_super, 0xa00, 0x100)
   1880	GEN_INT_ENTRY doorbell_super, virt=0
   1881EXC_REAL_END(doorbell_super, 0xa00, 0x100)
   1882EXC_VIRT_BEGIN(doorbell_super, 0x4a00, 0x100)
   1883	GEN_INT_ENTRY doorbell_super, virt=1
   1884EXC_VIRT_END(doorbell_super, 0x4a00, 0x100)
   1885EXC_COMMON_BEGIN(doorbell_super_common)
   1886	GEN_COMMON doorbell_super
   1887	addi	r3,r1,STACK_FRAME_OVERHEAD
   1888#ifdef CONFIG_PPC_DOORBELL
   1889	bl	doorbell_exception
   1890#else
   1891	bl	unknown_async_exception
   1892#endif
   1893	b	interrupt_return_srr
   1894
   1895
   1896EXC_REAL_NONE(0xb00, 0x100)
   1897EXC_VIRT_NONE(0x4b00, 0x100)
   1898
   1899/**
   1900 * Interrupt 0xc00 - System Call Interrupt (syscall, hcall).
   1901 * This is a synchronous interrupt invoked with the "sc" instruction. The
   1902 * system call is invoked with "sc 0" and does not alter the HV bit, so it
   1903 * is directed to the currently running OS. The hypercall is invoked with
   1904 * "sc 1" and it sets HV=1, so it elevates to hypervisor.
   1905 *
   1906 * In HPT, sc 1 always goes to 0xc00 real mode. In RADIX, sc 1 can go to
   1907 * 0x4c00 virtual mode.
   1908 *
   1909 * Handling:
   1910 * If the KVM test fires then it was due to a hypercall and is accordingly
   1911 * routed to KVM. Otherwise this executes a normal Linux system call.
   1912 *
   1913 * Call convention:
   1914 *
   1915 * syscall and hypercalls register conventions are documented in
   1916 * Documentation/powerpc/syscall64-abi.rst and
   1917 * Documentation/powerpc/papr_hcalls.rst respectively.
   1918 *
   1919 * The intersection of volatile registers that don't contain possible
   1920 * inputs is: cr0, xer, ctr. We may use these as scratch regs upon entry
   1921 * without saving, though xer is not a good idea to use, as hardware may
   1922 * interpret some bits so it may be costly to change them.
   1923 */
   1924INT_DEFINE_BEGIN(system_call)
   1925	IVEC=0xc00
   1926	IKVM_REAL=1
   1927	IKVM_VIRT=1
   1928	ICFAR=0
   1929INT_DEFINE_END(system_call)
   1930
   1931.macro SYSTEM_CALL virt
   1932#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
   1933	/*
   1934	 * There is a little bit of juggling to get syscall and hcall
   1935	 * working well. Save r13 in ctr to avoid using SPRG scratch
   1936	 * register.
   1937	 *
   1938	 * Userspace syscalls have already saved the PPR, hcalls must save
   1939	 * it before setting HMT_MEDIUM.
   1940	 */
   1941	mtctr	r13
   1942	GET_PACA(r13)
   1943	std	r10,PACA_EXGEN+EX_R10(r13)
   1944	INTERRUPT_TO_KERNEL
   1945	KVMTEST system_call kvm_hcall /* uses r10, branch to kvm_hcall */
   1946	mfctr	r9
   1947#else
   1948	mr	r9,r13
   1949	GET_PACA(r13)
   1950	INTERRUPT_TO_KERNEL
   1951#endif
   1952
   1953#ifdef CONFIG_PPC_FAST_ENDIAN_SWITCH
   1954BEGIN_FTR_SECTION
   1955	cmpdi	r0,0x1ebe
   1956	beq-	1f
   1957END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
   1958#endif
   1959
   1960	/* We reach here with PACA in r13, r13 in r9. */
   1961	mfspr	r11,SPRN_SRR0
   1962	mfspr	r12,SPRN_SRR1
   1963
   1964	HMT_MEDIUM
   1965
   1966	.if ! \virt
   1967	__LOAD_HANDLER(r10, system_call_common_real, real_vectors)
   1968	mtctr	r10
   1969	bctr
   1970	.else
   1971#ifdef CONFIG_RELOCATABLE
   1972	__LOAD_HANDLER(r10, system_call_common, virt_vectors)
   1973	mtctr	r10
   1974	bctr
   1975#else
   1976	b	system_call_common
   1977#endif
   1978	.endif
   1979
   1980#ifdef CONFIG_PPC_FAST_ENDIAN_SWITCH
   1981	/* Fast LE/BE switch system call */
   19821:	mfspr	r12,SPRN_SRR1
   1983	xori	r12,r12,MSR_LE
   1984	mtspr	SPRN_SRR1,r12
   1985	mr	r13,r9
   1986	RFI_TO_USER	/* return to userspace */
   1987	b	.	/* prevent speculative execution */
   1988#endif
   1989.endm
   1990
   1991EXC_REAL_BEGIN(system_call, 0xc00, 0x100)
   1992	SYSTEM_CALL 0
   1993EXC_REAL_END(system_call, 0xc00, 0x100)
   1994EXC_VIRT_BEGIN(system_call, 0x4c00, 0x100)
   1995	SYSTEM_CALL 1
   1996EXC_VIRT_END(system_call, 0x4c00, 0x100)
   1997
   1998#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
   1999TRAMP_REAL_BEGIN(kvm_hcall)
   2000	std	r9,PACA_EXGEN+EX_R9(r13)
   2001	std	r11,PACA_EXGEN+EX_R11(r13)
   2002	std	r12,PACA_EXGEN+EX_R12(r13)
   2003	mfcr	r9
   2004	mfctr	r10
   2005	std	r10,PACA_EXGEN+EX_R13(r13)
   2006	li	r10,0
   2007	std	r10,PACA_EXGEN+EX_CFAR(r13)
   2008	std	r10,PACA_EXGEN+EX_CTR(r13)
   2009	 /*
   2010	  * Save the PPR (on systems that support it) before changing to
   2011	  * HMT_MEDIUM. That allows the KVM code to save that value into the
   2012	  * guest state (it is the guest's PPR value).
   2013	  */
   2014BEGIN_FTR_SECTION
   2015	mfspr	r10,SPRN_PPR
   2016	std	r10,PACA_EXGEN+EX_PPR(r13)
   2017END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
   2018
   2019	HMT_MEDIUM
   2020
   2021#ifdef CONFIG_RELOCATABLE
   2022	/*
   2023	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
   2024	 * outside the head section.
   2025	 */
   2026	__LOAD_FAR_HANDLER(r10, kvmppc_hcall, real_trampolines)
   2027	mtctr   r10
   2028	bctr
   2029#else
   2030	b       kvmppc_hcall
   2031#endif
   2032#endif
   2033
   2034/**
   2035 * Interrupt 0xd00 - Trace Interrupt.
   2036 * This is a synchronous interrupt in response to instruction step or
   2037 * breakpoint faults.
   2038 */
   2039INT_DEFINE_BEGIN(single_step)
   2040	IVEC=0xd00
   2041#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   2042	IKVM_REAL=1
   2043#endif
   2044INT_DEFINE_END(single_step)
   2045
   2046EXC_REAL_BEGIN(single_step, 0xd00, 0x100)
   2047	GEN_INT_ENTRY single_step, virt=0
   2048EXC_REAL_END(single_step, 0xd00, 0x100)
   2049EXC_VIRT_BEGIN(single_step, 0x4d00, 0x100)
   2050	GEN_INT_ENTRY single_step, virt=1
   2051EXC_VIRT_END(single_step, 0x4d00, 0x100)
   2052EXC_COMMON_BEGIN(single_step_common)
   2053	GEN_COMMON single_step
   2054	addi	r3,r1,STACK_FRAME_OVERHEAD
   2055	bl	single_step_exception
   2056	b	interrupt_return_srr
   2057
   2058
   2059/**
   2060 * Interrupt 0xe00 - Hypervisor Data Storage Interrupt (HDSI).
   2061 * This is a synchronous interrupt in response to an MMU fault caused by a
   2062 * guest data access.
   2063 *
   2064 * Handling:
   2065 * This should always get routed to KVM. In radix MMU mode, this is caused
   2066 * by a guest nested radix access that can't be performed due to the
   2067 * partition scope page table. In hash mode, this can be caused by guests
   2068 * running with translation disabled (virtual real mode) or with VPM enabled.
   2069 * KVM will update the page table structures or disallow the access.
   2070 */
   2071INT_DEFINE_BEGIN(h_data_storage)
   2072	IVEC=0xe00
   2073	IHSRR=1
   2074	IDAR=1
   2075	IDSISR=1
   2076	IKVM_REAL=1
   2077	IKVM_VIRT=1
   2078INT_DEFINE_END(h_data_storage)
   2079
   2080EXC_REAL_BEGIN(h_data_storage, 0xe00, 0x20)
   2081	GEN_INT_ENTRY h_data_storage, virt=0, ool=1
   2082EXC_REAL_END(h_data_storage, 0xe00, 0x20)
   2083EXC_VIRT_BEGIN(h_data_storage, 0x4e00, 0x20)
   2084	GEN_INT_ENTRY h_data_storage, virt=1, ool=1
   2085EXC_VIRT_END(h_data_storage, 0x4e00, 0x20)
   2086EXC_COMMON_BEGIN(h_data_storage_common)
   2087	GEN_COMMON h_data_storage
   2088	addi    r3,r1,STACK_FRAME_OVERHEAD
   2089BEGIN_MMU_FTR_SECTION
   2090	bl      do_bad_page_fault_segv
   2091MMU_FTR_SECTION_ELSE
   2092	bl      unknown_exception
   2093ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
   2094	b       interrupt_return_hsrr
   2095
   2096
   2097/**
   2098 * Interrupt 0xe20 - Hypervisor Instruction Storage Interrupt (HISI).
   2099 * This is a synchronous interrupt in response to an MMU fault caused by a
   2100 * guest instruction fetch, similar to HDSI.
   2101 */
   2102INT_DEFINE_BEGIN(h_instr_storage)
   2103	IVEC=0xe20
   2104	IHSRR=1
   2105	IKVM_REAL=1
   2106	IKVM_VIRT=1
   2107INT_DEFINE_END(h_instr_storage)
   2108
   2109EXC_REAL_BEGIN(h_instr_storage, 0xe20, 0x20)
   2110	GEN_INT_ENTRY h_instr_storage, virt=0, ool=1
   2111EXC_REAL_END(h_instr_storage, 0xe20, 0x20)
   2112EXC_VIRT_BEGIN(h_instr_storage, 0x4e20, 0x20)
   2113	GEN_INT_ENTRY h_instr_storage, virt=1, ool=1
   2114EXC_VIRT_END(h_instr_storage, 0x4e20, 0x20)
   2115EXC_COMMON_BEGIN(h_instr_storage_common)
   2116	GEN_COMMON h_instr_storage
   2117	addi	r3,r1,STACK_FRAME_OVERHEAD
   2118	bl	unknown_exception
   2119	b	interrupt_return_hsrr
   2120
   2121
   2122/**
   2123 * Interrupt 0xe40 - Hypervisor Emulation Assistance Interrupt.
   2124 */
   2125INT_DEFINE_BEGIN(emulation_assist)
   2126	IVEC=0xe40
   2127	IHSRR=1
   2128	IKVM_REAL=1
   2129	IKVM_VIRT=1
   2130INT_DEFINE_END(emulation_assist)
   2131
   2132EXC_REAL_BEGIN(emulation_assist, 0xe40, 0x20)
   2133	GEN_INT_ENTRY emulation_assist, virt=0, ool=1
   2134EXC_REAL_END(emulation_assist, 0xe40, 0x20)
   2135EXC_VIRT_BEGIN(emulation_assist, 0x4e40, 0x20)
   2136	GEN_INT_ENTRY emulation_assist, virt=1, ool=1
   2137EXC_VIRT_END(emulation_assist, 0x4e40, 0x20)
   2138EXC_COMMON_BEGIN(emulation_assist_common)
   2139	GEN_COMMON emulation_assist
   2140	addi	r3,r1,STACK_FRAME_OVERHEAD
   2141	bl	emulation_assist_interrupt
   2142	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
   2143	b	interrupt_return_hsrr
   2144
   2145
   2146/**
   2147 * Interrupt 0xe60 - Hypervisor Maintenance Interrupt (HMI).
   2148 * This is an asynchronous interrupt caused by a Hypervisor Maintenance
   2149 * Exception. It is always taken in real mode but uses HSRR registers
   2150 * unlike SRESET and MCE.
   2151 *
   2152 * It is maskable in hardware by clearing MSR[EE], and partially soft-maskable
   2153 * with IRQS_DISABLED mask (i.e., local_irq_disable()).
   2154 *
   2155 * Handling:
   2156 * This is a special case, this is handled similarly to machine checks, with an
   2157 * initial real mode handler that is not soft-masked, which attempts to fix the
   2158 * problem. Then a regular handler which is soft-maskable and reports the
   2159 * problem.
   2160 *
   2161 * The emergency stack is used for the early real mode handler.
   2162 *
   2163 * XXX: unclear why MCE and HMI schemes could not be made common, e.g.,
   2164 * either use soft-masking for the MCE, or use irq_work for the HMI.
   2165 *
   2166 * KVM:
   2167 * Unlike MCE, this calls into KVM without calling the real mode handler
   2168 * first.
   2169 */
   2170INT_DEFINE_BEGIN(hmi_exception_early)
   2171	IVEC=0xe60
   2172	IHSRR=1
   2173	IREALMODE_COMMON=1
   2174	ISTACK=0
   2175	IKUAP=0 /* We don't touch AMR here, we never go to virtual mode */
   2176	IKVM_REAL=1
   2177INT_DEFINE_END(hmi_exception_early)
   2178
   2179INT_DEFINE_BEGIN(hmi_exception)
   2180	IVEC=0xe60
   2181	IHSRR=1
   2182	IMASK=IRQS_DISABLED
   2183	IKVM_REAL=1
   2184INT_DEFINE_END(hmi_exception)
   2185
   2186EXC_REAL_BEGIN(hmi_exception, 0xe60, 0x20)
   2187	GEN_INT_ENTRY hmi_exception_early, virt=0, ool=1
   2188EXC_REAL_END(hmi_exception, 0xe60, 0x20)
   2189EXC_VIRT_NONE(0x4e60, 0x20)
   2190
   2191EXC_COMMON_BEGIN(hmi_exception_early_common)
   2192	__GEN_REALMODE_COMMON_ENTRY hmi_exception_early
   2193
   2194	mr	r10,r1			/* Save r1 */
   2195	ld	r1,PACAEMERGSP(r13)	/* Use emergency stack for realmode */
   2196	subi	r1,r1,INT_FRAME_SIZE	/* alloc stack frame		*/
   2197
   2198	__GEN_COMMON_BODY hmi_exception_early
   2199
   2200	addi	r3,r1,STACK_FRAME_OVERHEAD
   2201	bl	hmi_exception_realmode
   2202	cmpdi	cr0,r3,0
   2203	bne	1f
   2204
   2205	EXCEPTION_RESTORE_REGS hsrr=1
   2206	HRFI_TO_USER_OR_KERNEL
   2207
   22081:
   2209	/*
   2210	 * Go to virtual mode and pull the HMI event information from
   2211	 * firmware.
   2212	 */
   2213	EXCEPTION_RESTORE_REGS hsrr=1
   2214	GEN_INT_ENTRY hmi_exception, virt=0
   2215
   2216EXC_COMMON_BEGIN(hmi_exception_common)
   2217	GEN_COMMON hmi_exception
   2218	addi	r3,r1,STACK_FRAME_OVERHEAD
   2219	bl	handle_hmi_exception
   2220	b	interrupt_return_hsrr
   2221
   2222
   2223/**
   2224 * Interrupt 0xe80 - Directed Hypervisor Doorbell Interrupt.
   2225 * This is an asynchronous interrupt in response to a msgsnd doorbell.
   2226 * Similar to the 0xa00 doorbell but for host rather than guest.
   2227 *
   2228 * CFAR is not required (similar to doorbell_interrupt), unless KVM HV
   2229 * is enabled, in which case it may be a guest exit. Most PowerNV kernels
   2230 * include KVM support so it would be nice if this could be dynamically
   2231 * patched out if KVM was not currently running any guests.
   2232 */
   2233INT_DEFINE_BEGIN(h_doorbell)
   2234	IVEC=0xe80
   2235	IHSRR=1
   2236	IMASK=IRQS_DISABLED
   2237	IKVM_REAL=1
   2238	IKVM_VIRT=1
   2239#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE
   2240	ICFAR=0
   2241#endif
   2242INT_DEFINE_END(h_doorbell)
   2243
   2244EXC_REAL_BEGIN(h_doorbell, 0xe80, 0x20)
   2245	GEN_INT_ENTRY h_doorbell, virt=0, ool=1
   2246EXC_REAL_END(h_doorbell, 0xe80, 0x20)
   2247EXC_VIRT_BEGIN(h_doorbell, 0x4e80, 0x20)
   2248	GEN_INT_ENTRY h_doorbell, virt=1, ool=1
   2249EXC_VIRT_END(h_doorbell, 0x4e80, 0x20)
   2250EXC_COMMON_BEGIN(h_doorbell_common)
   2251	GEN_COMMON h_doorbell
   2252	addi	r3,r1,STACK_FRAME_OVERHEAD
   2253#ifdef CONFIG_PPC_DOORBELL
   2254	bl	doorbell_exception
   2255#else
   2256	bl	unknown_async_exception
   2257#endif
   2258	b	interrupt_return_hsrr
   2259
   2260
   2261/**
   2262 * Interrupt 0xea0 - Hypervisor Virtualization Interrupt.
   2263 * This is an asynchronous interrupt in response to an "external exception".
   2264 * Similar to 0x500 but for host only.
   2265 *
   2266 * Like h_doorbell, CFAR is only required for KVM HV because this can be
   2267 * a guest exit.
   2268 */
   2269INT_DEFINE_BEGIN(h_virt_irq)
   2270	IVEC=0xea0
   2271	IHSRR=1
   2272	IMASK=IRQS_DISABLED
   2273	IKVM_REAL=1
   2274	IKVM_VIRT=1
   2275#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE
   2276	ICFAR=0
   2277#endif
   2278INT_DEFINE_END(h_virt_irq)
   2279
   2280EXC_REAL_BEGIN(h_virt_irq, 0xea0, 0x20)
   2281	GEN_INT_ENTRY h_virt_irq, virt=0, ool=1
   2282EXC_REAL_END(h_virt_irq, 0xea0, 0x20)
   2283EXC_VIRT_BEGIN(h_virt_irq, 0x4ea0, 0x20)
   2284	GEN_INT_ENTRY h_virt_irq, virt=1, ool=1
   2285EXC_VIRT_END(h_virt_irq, 0x4ea0, 0x20)
   2286EXC_COMMON_BEGIN(h_virt_irq_common)
   2287	GEN_COMMON h_virt_irq
   2288	addi	r3,r1,STACK_FRAME_OVERHEAD
   2289	bl	do_IRQ
   2290	b	interrupt_return_hsrr
   2291
   2292
   2293EXC_REAL_NONE(0xec0, 0x20)
   2294EXC_VIRT_NONE(0x4ec0, 0x20)
   2295EXC_REAL_NONE(0xee0, 0x20)
   2296EXC_VIRT_NONE(0x4ee0, 0x20)
   2297
   2298
   2299/*
   2300 * Interrupt 0xf00 - Performance Monitor Interrupt (PMI, PMU).
   2301 * This is an asynchronous interrupt in response to a PMU exception.
   2302 * It is maskable in hardware by clearing MSR[EE], and soft-maskable with
   2303 * IRQS_PMI_DISABLED mask (NOTE: NOT local_irq_disable()).
   2304 *
   2305 * Handling:
   2306 * This calls into the perf subsystem.
   2307 *
   2308 * Like the watchdog soft-nmi, it appears an NMI interrupt to Linux, in that it
   2309 * runs under local_irq_disable. However it may be soft-masked in
   2310 * powerpc-specific code.
   2311 *
   2312 * If soft masked, the masked handler will note the pending interrupt for
   2313 * replay, and clear MSR[EE] in the interrupted context.
   2314 *
   2315 * CFAR is not used by perf interrupts so not required.
   2316 */
   2317INT_DEFINE_BEGIN(performance_monitor)
   2318	IVEC=0xf00
   2319	IMASK=IRQS_PMI_DISABLED
   2320#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   2321	IKVM_REAL=1
   2322#endif
   2323	ICFAR=0
   2324INT_DEFINE_END(performance_monitor)
   2325
   2326EXC_REAL_BEGIN(performance_monitor, 0xf00, 0x20)
   2327	GEN_INT_ENTRY performance_monitor, virt=0, ool=1
   2328EXC_REAL_END(performance_monitor, 0xf00, 0x20)
   2329EXC_VIRT_BEGIN(performance_monitor, 0x4f00, 0x20)
   2330	GEN_INT_ENTRY performance_monitor, virt=1, ool=1
   2331EXC_VIRT_END(performance_monitor, 0x4f00, 0x20)
   2332EXC_COMMON_BEGIN(performance_monitor_common)
   2333	GEN_COMMON performance_monitor
   2334	addi	r3,r1,STACK_FRAME_OVERHEAD
   2335	bl	performance_monitor_exception
   2336	b	interrupt_return_srr
   2337
   2338
   2339/**
   2340 * Interrupt 0xf20 - Vector Unavailable Interrupt.
   2341 * This is a synchronous interrupt in response to
   2342 * executing a vector (or altivec) instruction with MSR[VEC]=0.
   2343 * Similar to FP unavailable.
   2344 */
   2345INT_DEFINE_BEGIN(altivec_unavailable)
   2346	IVEC=0xf20
   2347#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   2348	IKVM_REAL=1
   2349#endif
   2350INT_DEFINE_END(altivec_unavailable)
   2351
   2352EXC_REAL_BEGIN(altivec_unavailable, 0xf20, 0x20)
   2353	GEN_INT_ENTRY altivec_unavailable, virt=0, ool=1
   2354EXC_REAL_END(altivec_unavailable, 0xf20, 0x20)
   2355EXC_VIRT_BEGIN(altivec_unavailable, 0x4f20, 0x20)
   2356	GEN_INT_ENTRY altivec_unavailable, virt=1, ool=1
   2357EXC_VIRT_END(altivec_unavailable, 0x4f20, 0x20)
   2358EXC_COMMON_BEGIN(altivec_unavailable_common)
   2359	GEN_COMMON altivec_unavailable
   2360#ifdef CONFIG_ALTIVEC
   2361BEGIN_FTR_SECTION
   2362	beq	1f
   2363#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
   2364  BEGIN_FTR_SECTION_NESTED(69)
   2365	/* Test if 2 TM state bits are zero.  If non-zero (ie. userspace was in
   2366	 * transaction), go do TM stuff
   2367	 */
   2368	rldicl.	r0, r12, (64-MSR_TS_LG), (64-2)
   2369	bne-	2f
   2370  END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
   2371#endif
   2372	bl	load_up_altivec
   2373	b	fast_interrupt_return_srr
   2374#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
   23752:	/* User process was in a transaction */
   2376	addi	r3,r1,STACK_FRAME_OVERHEAD
   2377	bl	altivec_unavailable_tm
   2378	b	interrupt_return_srr
   2379#endif
   23801:
   2381END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
   2382#endif
   2383	addi	r3,r1,STACK_FRAME_OVERHEAD
   2384	bl	altivec_unavailable_exception
   2385	b	interrupt_return_srr
   2386
   2387
   2388/**
   2389 * Interrupt 0xf40 - VSX Unavailable Interrupt.
   2390 * This is a synchronous interrupt in response to
   2391 * executing a VSX instruction with MSR[VSX]=0.
   2392 * Similar to FP unavailable.
   2393 */
   2394INT_DEFINE_BEGIN(vsx_unavailable)
   2395	IVEC=0xf40
   2396#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   2397	IKVM_REAL=1
   2398#endif
   2399INT_DEFINE_END(vsx_unavailable)
   2400
   2401EXC_REAL_BEGIN(vsx_unavailable, 0xf40, 0x20)
   2402	GEN_INT_ENTRY vsx_unavailable, virt=0, ool=1
   2403EXC_REAL_END(vsx_unavailable, 0xf40, 0x20)
   2404EXC_VIRT_BEGIN(vsx_unavailable, 0x4f40, 0x20)
   2405	GEN_INT_ENTRY vsx_unavailable, virt=1, ool=1
   2406EXC_VIRT_END(vsx_unavailable, 0x4f40, 0x20)
   2407EXC_COMMON_BEGIN(vsx_unavailable_common)
   2408	GEN_COMMON vsx_unavailable
   2409#ifdef CONFIG_VSX
   2410BEGIN_FTR_SECTION
   2411	beq	1f
   2412#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
   2413  BEGIN_FTR_SECTION_NESTED(69)
   2414	/* Test if 2 TM state bits are zero.  If non-zero (ie. userspace was in
   2415	 * transaction), go do TM stuff
   2416	 */
   2417	rldicl.	r0, r12, (64-MSR_TS_LG), (64-2)
   2418	bne-	2f
   2419  END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
   2420#endif
   2421	b	load_up_vsx
   2422#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
   24232:	/* User process was in a transaction */
   2424	addi	r3,r1,STACK_FRAME_OVERHEAD
   2425	bl	vsx_unavailable_tm
   2426	b	interrupt_return_srr
   2427#endif
   24281:
   2429END_FTR_SECTION_IFSET(CPU_FTR_VSX)
   2430#endif
   2431	addi	r3,r1,STACK_FRAME_OVERHEAD
   2432	bl	vsx_unavailable_exception
   2433	b	interrupt_return_srr
   2434
   2435
   2436/**
   2437 * Interrupt 0xf60 - Facility Unavailable Interrupt.
   2438 * This is a synchronous interrupt in response to
   2439 * executing an instruction without access to the facility that can be
   2440 * resolved by the OS (e.g., FSCR, MSR).
   2441 * Similar to FP unavailable.
   2442 */
   2443INT_DEFINE_BEGIN(facility_unavailable)
   2444	IVEC=0xf60
   2445#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   2446	IKVM_REAL=1
   2447#endif
   2448INT_DEFINE_END(facility_unavailable)
   2449
   2450EXC_REAL_BEGIN(facility_unavailable, 0xf60, 0x20)
   2451	GEN_INT_ENTRY facility_unavailable, virt=0, ool=1
   2452EXC_REAL_END(facility_unavailable, 0xf60, 0x20)
   2453EXC_VIRT_BEGIN(facility_unavailable, 0x4f60, 0x20)
   2454	GEN_INT_ENTRY facility_unavailable, virt=1, ool=1
   2455EXC_VIRT_END(facility_unavailable, 0x4f60, 0x20)
   2456EXC_COMMON_BEGIN(facility_unavailable_common)
   2457	GEN_COMMON facility_unavailable
   2458	addi	r3,r1,STACK_FRAME_OVERHEAD
   2459	bl	facility_unavailable_exception
   2460	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
   2461	b	interrupt_return_srr
   2462
   2463
   2464/**
   2465 * Interrupt 0xf60 - Hypervisor Facility Unavailable Interrupt.
   2466 * This is a synchronous interrupt in response to
   2467 * executing an instruction without access to the facility that can only
   2468 * be resolved in HV mode (e.g., HFSCR).
   2469 * Similar to FP unavailable.
   2470 */
   2471INT_DEFINE_BEGIN(h_facility_unavailable)
   2472	IVEC=0xf80
   2473	IHSRR=1
   2474	IKVM_REAL=1
   2475	IKVM_VIRT=1
   2476INT_DEFINE_END(h_facility_unavailable)
   2477
   2478EXC_REAL_BEGIN(h_facility_unavailable, 0xf80, 0x20)
   2479	GEN_INT_ENTRY h_facility_unavailable, virt=0, ool=1
   2480EXC_REAL_END(h_facility_unavailable, 0xf80, 0x20)
   2481EXC_VIRT_BEGIN(h_facility_unavailable, 0x4f80, 0x20)
   2482	GEN_INT_ENTRY h_facility_unavailable, virt=1, ool=1
   2483EXC_VIRT_END(h_facility_unavailable, 0x4f80, 0x20)
   2484EXC_COMMON_BEGIN(h_facility_unavailable_common)
   2485	GEN_COMMON h_facility_unavailable
   2486	addi	r3,r1,STACK_FRAME_OVERHEAD
   2487	bl	facility_unavailable_exception
   2488	REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
   2489	b	interrupt_return_hsrr
   2490
   2491
   2492EXC_REAL_NONE(0xfa0, 0x20)
   2493EXC_VIRT_NONE(0x4fa0, 0x20)
   2494EXC_REAL_NONE(0xfc0, 0x20)
   2495EXC_VIRT_NONE(0x4fc0, 0x20)
   2496EXC_REAL_NONE(0xfe0, 0x20)
   2497EXC_VIRT_NONE(0x4fe0, 0x20)
   2498
   2499EXC_REAL_NONE(0x1000, 0x100)
   2500EXC_VIRT_NONE(0x5000, 0x100)
   2501EXC_REAL_NONE(0x1100, 0x100)
   2502EXC_VIRT_NONE(0x5100, 0x100)
   2503
   2504#ifdef CONFIG_CBE_RAS
   2505INT_DEFINE_BEGIN(cbe_system_error)
   2506	IVEC=0x1200
   2507	IHSRR=1
   2508INT_DEFINE_END(cbe_system_error)
   2509
   2510EXC_REAL_BEGIN(cbe_system_error, 0x1200, 0x100)
   2511	GEN_INT_ENTRY cbe_system_error, virt=0
   2512EXC_REAL_END(cbe_system_error, 0x1200, 0x100)
   2513EXC_VIRT_NONE(0x5200, 0x100)
   2514EXC_COMMON_BEGIN(cbe_system_error_common)
   2515	GEN_COMMON cbe_system_error
   2516	addi	r3,r1,STACK_FRAME_OVERHEAD
   2517	bl	cbe_system_error_exception
   2518	b	interrupt_return_hsrr
   2519
   2520#else /* CONFIG_CBE_RAS */
   2521EXC_REAL_NONE(0x1200, 0x100)
   2522EXC_VIRT_NONE(0x5200, 0x100)
   2523#endif
   2524
   2525/**
   2526 * Interrupt 0x1300 - Instruction Address Breakpoint Interrupt.
   2527 * This has been removed from the ISA before 2.01, which is the earliest
   2528 * 64-bit BookS ISA supported, however the G5 / 970 implements this
   2529 * interrupt with a non-architected feature available through the support
   2530 * processor interface.
   2531 */
   2532INT_DEFINE_BEGIN(instruction_breakpoint)
   2533	IVEC=0x1300
   2534#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   2535	IKVM_REAL=1
   2536#endif
   2537INT_DEFINE_END(instruction_breakpoint)
   2538
   2539EXC_REAL_BEGIN(instruction_breakpoint, 0x1300, 0x100)
   2540	GEN_INT_ENTRY instruction_breakpoint, virt=0
   2541EXC_REAL_END(instruction_breakpoint, 0x1300, 0x100)
   2542EXC_VIRT_BEGIN(instruction_breakpoint, 0x5300, 0x100)
   2543	GEN_INT_ENTRY instruction_breakpoint, virt=1
   2544EXC_VIRT_END(instruction_breakpoint, 0x5300, 0x100)
   2545EXC_COMMON_BEGIN(instruction_breakpoint_common)
   2546	GEN_COMMON instruction_breakpoint
   2547	addi	r3,r1,STACK_FRAME_OVERHEAD
   2548	bl	instruction_breakpoint_exception
   2549	b	interrupt_return_srr
   2550
   2551
   2552EXC_REAL_NONE(0x1400, 0x100)
   2553EXC_VIRT_NONE(0x5400, 0x100)
   2554
   2555/**
   2556 * Interrupt 0x1500 - Soft Patch Interrupt
   2557 *
   2558 * Handling:
   2559 * This is an implementation specific interrupt which can be used for a
   2560 * range of exceptions.
   2561 *
   2562 * This interrupt handler is unique in that it runs the denormal assist
   2563 * code even for guests (and even in guest context) without going to KVM,
   2564 * for speed. POWER9 does not raise denorm exceptions, so this special case
   2565 * could be phased out in future to reduce special cases.
   2566 */
   2567INT_DEFINE_BEGIN(denorm_exception)
   2568	IVEC=0x1500
   2569	IHSRR=1
   2570	IBRANCH_TO_COMMON=0
   2571	IKVM_REAL=1
   2572INT_DEFINE_END(denorm_exception)
   2573
   2574EXC_REAL_BEGIN(denorm_exception, 0x1500, 0x100)
   2575	GEN_INT_ENTRY denorm_exception, virt=0
   2576#ifdef CONFIG_PPC_DENORMALISATION
   2577	andis.	r10,r12,(HSRR1_DENORM)@h /* denorm? */
   2578	bne+	denorm_assist
   2579#endif
   2580	GEN_BRANCH_TO_COMMON denorm_exception, virt=0
   2581EXC_REAL_END(denorm_exception, 0x1500, 0x100)
   2582#ifdef CONFIG_PPC_DENORMALISATION
   2583EXC_VIRT_BEGIN(denorm_exception, 0x5500, 0x100)
   2584	GEN_INT_ENTRY denorm_exception, virt=1
   2585	andis.	r10,r12,(HSRR1_DENORM)@h /* denorm? */
   2586	bne+	denorm_assist
   2587	GEN_BRANCH_TO_COMMON denorm_exception, virt=1
   2588EXC_VIRT_END(denorm_exception, 0x5500, 0x100)
   2589#else
   2590EXC_VIRT_NONE(0x5500, 0x100)
   2591#endif
   2592
   2593#ifdef CONFIG_PPC_DENORMALISATION
   2594TRAMP_REAL_BEGIN(denorm_assist)
   2595BEGIN_FTR_SECTION
   2596/*
   2597 * To denormalise we need to move a copy of the register to itself.
   2598 * For POWER6 do that here for all FP regs.
   2599 */
   2600	mfmsr	r10
   2601	ori	r10,r10,(MSR_FP|MSR_FE0|MSR_FE1)
   2602	xori	r10,r10,(MSR_FE0|MSR_FE1)
   2603	mtmsrd	r10
   2604	sync
   2605
   2606	.Lreg=0
   2607	.rept 32
   2608	fmr	.Lreg,.Lreg
   2609	.Lreg=.Lreg+1
   2610	.endr
   2611
   2612FTR_SECTION_ELSE
   2613/*
   2614 * To denormalise we need to move a copy of the register to itself.
   2615 * For POWER7 do that here for the first 32 VSX registers only.
   2616 */
   2617	mfmsr	r10
   2618	oris	r10,r10,MSR_VSX@h
   2619	mtmsrd	r10
   2620	sync
   2621
   2622	.Lreg=0
   2623	.rept 32
   2624	XVCPSGNDP(.Lreg,.Lreg,.Lreg)
   2625	.Lreg=.Lreg+1
   2626	.endr
   2627
   2628ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_206)
   2629
   2630BEGIN_FTR_SECTION
   2631	b	denorm_done
   2632END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
   2633/*
   2634 * To denormalise we need to move a copy of the register to itself.
   2635 * For POWER8 we need to do that for all 64 VSX registers
   2636 */
   2637	.Lreg=32
   2638	.rept 32
   2639	XVCPSGNDP(.Lreg,.Lreg,.Lreg)
   2640	.Lreg=.Lreg+1
   2641	.endr
   2642
   2643denorm_done:
   2644	mfspr	r11,SPRN_HSRR0
   2645	subi	r11,r11,4
   2646	mtspr	SPRN_HSRR0,r11
   2647	mtcrf	0x80,r9
   2648	ld	r9,PACA_EXGEN+EX_R9(r13)
   2649BEGIN_FTR_SECTION
   2650	ld	r10,PACA_EXGEN+EX_PPR(r13)
   2651	mtspr	SPRN_PPR,r10
   2652END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
   2653BEGIN_FTR_SECTION
   2654	ld	r10,PACA_EXGEN+EX_CFAR(r13)
   2655	mtspr	SPRN_CFAR,r10
   2656END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
   2657	li	r10,0
   2658	stb	r10,PACAHSRR_VALID(r13)
   2659	ld	r10,PACA_EXGEN+EX_R10(r13)
   2660	ld	r11,PACA_EXGEN+EX_R11(r13)
   2661	ld	r12,PACA_EXGEN+EX_R12(r13)
   2662	ld	r13,PACA_EXGEN+EX_R13(r13)
   2663	HRFI_TO_UNKNOWN
   2664	b	.
   2665#endif
   2666
   2667EXC_COMMON_BEGIN(denorm_exception_common)
   2668	GEN_COMMON denorm_exception
   2669	addi	r3,r1,STACK_FRAME_OVERHEAD
   2670	bl	unknown_exception
   2671	b	interrupt_return_hsrr
   2672
   2673
   2674#ifdef CONFIG_CBE_RAS
   2675INT_DEFINE_BEGIN(cbe_maintenance)
   2676	IVEC=0x1600
   2677	IHSRR=1
   2678INT_DEFINE_END(cbe_maintenance)
   2679
   2680EXC_REAL_BEGIN(cbe_maintenance, 0x1600, 0x100)
   2681	GEN_INT_ENTRY cbe_maintenance, virt=0
   2682EXC_REAL_END(cbe_maintenance, 0x1600, 0x100)
   2683EXC_VIRT_NONE(0x5600, 0x100)
   2684EXC_COMMON_BEGIN(cbe_maintenance_common)
   2685	GEN_COMMON cbe_maintenance
   2686	addi	r3,r1,STACK_FRAME_OVERHEAD
   2687	bl	cbe_maintenance_exception
   2688	b	interrupt_return_hsrr
   2689
   2690#else /* CONFIG_CBE_RAS */
   2691EXC_REAL_NONE(0x1600, 0x100)
   2692EXC_VIRT_NONE(0x5600, 0x100)
   2693#endif
   2694
   2695
   2696INT_DEFINE_BEGIN(altivec_assist)
   2697	IVEC=0x1700
   2698#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
   2699	IKVM_REAL=1
   2700#endif
   2701INT_DEFINE_END(altivec_assist)
   2702
   2703EXC_REAL_BEGIN(altivec_assist, 0x1700, 0x100)
   2704	GEN_INT_ENTRY altivec_assist, virt=0
   2705EXC_REAL_END(altivec_assist, 0x1700, 0x100)
   2706EXC_VIRT_BEGIN(altivec_assist, 0x5700, 0x100)
   2707	GEN_INT_ENTRY altivec_assist, virt=1
   2708EXC_VIRT_END(altivec_assist, 0x5700, 0x100)
   2709EXC_COMMON_BEGIN(altivec_assist_common)
   2710	GEN_COMMON altivec_assist
   2711	addi	r3,r1,STACK_FRAME_OVERHEAD
   2712#ifdef CONFIG_ALTIVEC
   2713	bl	altivec_assist_exception
   2714	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
   2715#else
   2716	bl	unknown_exception
   2717#endif
   2718	b	interrupt_return_srr
   2719
   2720
   2721#ifdef CONFIG_CBE_RAS
   2722INT_DEFINE_BEGIN(cbe_thermal)
   2723	IVEC=0x1800
   2724	IHSRR=1
   2725INT_DEFINE_END(cbe_thermal)
   2726
   2727EXC_REAL_BEGIN(cbe_thermal, 0x1800, 0x100)
   2728	GEN_INT_ENTRY cbe_thermal, virt=0
   2729EXC_REAL_END(cbe_thermal, 0x1800, 0x100)
   2730EXC_VIRT_NONE(0x5800, 0x100)
   2731EXC_COMMON_BEGIN(cbe_thermal_common)
   2732	GEN_COMMON cbe_thermal
   2733	addi	r3,r1,STACK_FRAME_OVERHEAD
   2734	bl	cbe_thermal_exception
   2735	b	interrupt_return_hsrr
   2736
   2737#else /* CONFIG_CBE_RAS */
   2738EXC_REAL_NONE(0x1800, 0x100)
   2739EXC_VIRT_NONE(0x5800, 0x100)
   2740#endif
   2741
   2742
   2743#ifdef CONFIG_PPC_WATCHDOG
   2744
   2745INT_DEFINE_BEGIN(soft_nmi)
   2746	IVEC=0x900
   2747	ISTACK=0
   2748	ICFAR=0
   2749INT_DEFINE_END(soft_nmi)
   2750
   2751/*
   2752 * Branch to soft_nmi_interrupt using the emergency stack. The emergency
   2753 * stack is one that is usable by maskable interrupts so long as MSR_EE
   2754 * remains off. It is used for recovery when something has corrupted the
   2755 * normal kernel stack, for example. The "soft NMI" must not use the process
   2756 * stack because we want irq disabled sections to avoid touching the stack
   2757 * at all (other than PMU interrupts), so use the emergency stack for this,
   2758 * and run it entirely with interrupts hard disabled.
   2759 */
   2760EXC_COMMON_BEGIN(soft_nmi_common)
   2761	mr	r10,r1
   2762	ld	r1,PACAEMERGSP(r13)
   2763	subi	r1,r1,INT_FRAME_SIZE
   2764	__GEN_COMMON_BODY soft_nmi
   2765
   2766	addi	r3,r1,STACK_FRAME_OVERHEAD
   2767	bl	soft_nmi_interrupt
   2768
   2769	/* Clear MSR_RI before setting SRR0 and SRR1. */
   2770	li	r9,0
   2771	mtmsrd	r9,1
   2772
   2773	kuap_kernel_restore r9, r10
   2774
   2775	EXCEPTION_RESTORE_REGS hsrr=0
   2776	RFI_TO_KERNEL
   2777
   2778#endif /* CONFIG_PPC_WATCHDOG */
   2779
   2780/*
   2781 * An interrupt came in while soft-disabled. We set paca->irq_happened, then:
   2782 * - If it was a decrementer interrupt, we bump the dec to max and and return.
   2783 * - If it was a doorbell we return immediately since doorbells are edge
   2784 *   triggered and won't automatically refire.
   2785 * - If it was a HMI we return immediately since we handled it in realmode
   2786 *   and it won't refire.
   2787 * - Else it is one of PACA_IRQ_MUST_HARD_MASK, so hard disable and return.
   2788 * This is called with r10 containing the value to OR to the paca field.
   2789 */
   2790.macro MASKED_INTERRUPT hsrr=0
   2791	.if \hsrr
   2792masked_Hinterrupt:
   2793	.else
   2794masked_interrupt:
   2795	.endif
   2796	stw	r9,PACA_EXGEN+EX_CCR(r13)
   2797	lbz	r9,PACAIRQHAPPENED(r13)
   2798	or	r9,r9,r10
   2799	stb	r9,PACAIRQHAPPENED(r13)
   2800
   2801	.if ! \hsrr
   2802	cmpwi	r10,PACA_IRQ_DEC
   2803	bne	1f
   2804	LOAD_REG_IMMEDIATE(r9, 0x7fffffff)
   2805	mtspr	SPRN_DEC,r9
   2806#ifdef CONFIG_PPC_WATCHDOG
   2807	lwz	r9,PACA_EXGEN+EX_CCR(r13)
   2808	b	soft_nmi_common
   2809#else
   2810	b	2f
   2811#endif
   2812	.endif
   2813
   28141:	andi.	r10,r10,PACA_IRQ_MUST_HARD_MASK
   2815	beq	2f
   2816	xori	r12,r12,MSR_EE	/* clear MSR_EE */
   2817	.if \hsrr
   2818	mtspr	SPRN_HSRR1,r12
   2819	.else
   2820	mtspr	SPRN_SRR1,r12
   2821	.endif
   2822	ori	r9,r9,PACA_IRQ_HARD_DIS
   2823	stb	r9,PACAIRQHAPPENED(r13)
   28242:	/* done */
   2825	li	r9,0
   2826	.if \hsrr
   2827	stb	r9,PACAHSRR_VALID(r13)
   2828	.else
   2829	stb	r9,PACASRR_VALID(r13)
   2830	.endif
   2831
   2832	SEARCH_RESTART_TABLE
   2833	cmpdi	r12,0
   2834	beq	3f
   2835	.if \hsrr
   2836	mtspr	SPRN_HSRR0,r12
   2837	.else
   2838	mtspr	SPRN_SRR0,r12
   2839	.endif
   28403:
   2841
   2842	ld	r9,PACA_EXGEN+EX_CTR(r13)
   2843	mtctr	r9
   2844	lwz	r9,PACA_EXGEN+EX_CCR(r13)
   2845	mtcrf	0x80,r9
   2846	std	r1,PACAR1(r13)
   2847	ld	r9,PACA_EXGEN+EX_R9(r13)
   2848	ld	r10,PACA_EXGEN+EX_R10(r13)
   2849	ld	r11,PACA_EXGEN+EX_R11(r13)
   2850	ld	r12,PACA_EXGEN+EX_R12(r13)
   2851	ld	r13,PACA_EXGEN+EX_R13(r13)
   2852	/* May return to masked low address where r13 is not set up */
   2853	.if \hsrr
   2854	HRFI_TO_KERNEL
   2855	.else
   2856	RFI_TO_KERNEL
   2857	.endif
   2858	b	.
   2859.endm
   2860
   2861TRAMP_REAL_BEGIN(stf_barrier_fallback)
   2862	std	r9,PACA_EXRFI+EX_R9(r13)
   2863	std	r10,PACA_EXRFI+EX_R10(r13)
   2864	sync
   2865	ld	r9,PACA_EXRFI+EX_R9(r13)
   2866	ld	r10,PACA_EXRFI+EX_R10(r13)
   2867	ori	31,31,0
   2868	.rept 14
   2869	b	1f
   28701:
   2871	.endr
   2872	blr
   2873
   2874/* Clobbers r10, r11, ctr */
   2875.macro L1D_DISPLACEMENT_FLUSH
   2876	ld	r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
   2877	ld	r11,PACA_L1D_FLUSH_SIZE(r13)
   2878	srdi	r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
   2879	mtctr	r11
   2880	DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
   2881
   2882	/* order ld/st prior to dcbt stop all streams with flushing */
   2883	sync
   2884
   2885	/*
   2886	 * The load addresses are at staggered offsets within cachelines,
   2887	 * which suits some pipelines better (on others it should not
   2888	 * hurt).
   2889	 */
   28901:
   2891	ld	r11,(0x80 + 8)*0(r10)
   2892	ld	r11,(0x80 + 8)*1(r10)
   2893	ld	r11,(0x80 + 8)*2(r10)
   2894	ld	r11,(0x80 + 8)*3(r10)
   2895	ld	r11,(0x80 + 8)*4(r10)
   2896	ld	r11,(0x80 + 8)*5(r10)
   2897	ld	r11,(0x80 + 8)*6(r10)
   2898	ld	r11,(0x80 + 8)*7(r10)
   2899	addi	r10,r10,0x80*8
   2900	bdnz	1b
   2901.endm
   2902
   2903TRAMP_REAL_BEGIN(entry_flush_fallback)
   2904	std	r9,PACA_EXRFI+EX_R9(r13)
   2905	std	r10,PACA_EXRFI+EX_R10(r13)
   2906	std	r11,PACA_EXRFI+EX_R11(r13)
   2907	mfctr	r9
   2908	L1D_DISPLACEMENT_FLUSH
   2909	mtctr	r9
   2910	ld	r9,PACA_EXRFI+EX_R9(r13)
   2911	ld	r10,PACA_EXRFI+EX_R10(r13)
   2912	ld	r11,PACA_EXRFI+EX_R11(r13)
   2913	blr
   2914
   2915/*
   2916 * The SCV entry flush happens with interrupts enabled, so it must disable
   2917 * to prevent EXRFI being clobbered by NMIs (e.g., soft_nmi_common). r10
   2918 * (containing LR) does not need to be preserved here because scv entry
   2919 * puts 0 in the pt_regs, CTR can be clobbered for the same reason.
   2920 */
   2921TRAMP_REAL_BEGIN(scv_entry_flush_fallback)
   2922	li	r10,0
   2923	mtmsrd	r10,1
   2924	lbz	r10,PACAIRQHAPPENED(r13)
   2925	ori	r10,r10,PACA_IRQ_HARD_DIS
   2926	stb	r10,PACAIRQHAPPENED(r13)
   2927	std	r11,PACA_EXRFI+EX_R11(r13)
   2928	L1D_DISPLACEMENT_FLUSH
   2929	ld	r11,PACA_EXRFI+EX_R11(r13)
   2930	li	r10,MSR_RI
   2931	mtmsrd	r10,1
   2932	blr
   2933
   2934TRAMP_REAL_BEGIN(rfi_flush_fallback)
   2935	SET_SCRATCH0(r13);
   2936	GET_PACA(r13);
   2937	std	r1,PACA_EXRFI+EX_R12(r13)
   2938	ld	r1,PACAKSAVE(r13)
   2939	std	r9,PACA_EXRFI+EX_R9(r13)
   2940	std	r10,PACA_EXRFI+EX_R10(r13)
   2941	std	r11,PACA_EXRFI+EX_R11(r13)
   2942	mfctr	r9
   2943	L1D_DISPLACEMENT_FLUSH
   2944	mtctr	r9
   2945	ld	r9,PACA_EXRFI+EX_R9(r13)
   2946	ld	r10,PACA_EXRFI+EX_R10(r13)
   2947	ld	r11,PACA_EXRFI+EX_R11(r13)
   2948	ld	r1,PACA_EXRFI+EX_R12(r13)
   2949	GET_SCRATCH0(r13);
   2950	rfid
   2951
   2952TRAMP_REAL_BEGIN(hrfi_flush_fallback)
   2953	SET_SCRATCH0(r13);
   2954	GET_PACA(r13);
   2955	std	r1,PACA_EXRFI+EX_R12(r13)
   2956	ld	r1,PACAKSAVE(r13)
   2957	std	r9,PACA_EXRFI+EX_R9(r13)
   2958	std	r10,PACA_EXRFI+EX_R10(r13)
   2959	std	r11,PACA_EXRFI+EX_R11(r13)
   2960	mfctr	r9
   2961	L1D_DISPLACEMENT_FLUSH
   2962	mtctr	r9
   2963	ld	r9,PACA_EXRFI+EX_R9(r13)
   2964	ld	r10,PACA_EXRFI+EX_R10(r13)
   2965	ld	r11,PACA_EXRFI+EX_R11(r13)
   2966	ld	r1,PACA_EXRFI+EX_R12(r13)
   2967	GET_SCRATCH0(r13);
   2968	hrfid
   2969
   2970TRAMP_REAL_BEGIN(rfscv_flush_fallback)
   2971	/* system call volatile */
   2972	mr	r7,r13
   2973	GET_PACA(r13);
   2974	mr	r8,r1
   2975	ld	r1,PACAKSAVE(r13)
   2976	mfctr	r9
   2977	ld	r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
   2978	ld	r11,PACA_L1D_FLUSH_SIZE(r13)
   2979	srdi	r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
   2980	mtctr	r11
   2981	DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
   2982
   2983	/* order ld/st prior to dcbt stop all streams with flushing */
   2984	sync
   2985
   2986	/*
   2987	 * The load adresses are at staggered offsets within cachelines,
   2988	 * which suits some pipelines better (on others it should not
   2989	 * hurt).
   2990	 */
   29911:
   2992	ld	r11,(0x80 + 8)*0(r10)
   2993	ld	r11,(0x80 + 8)*1(r10)
   2994	ld	r11,(0x80 + 8)*2(r10)
   2995	ld	r11,(0x80 + 8)*3(r10)
   2996	ld	r11,(0x80 + 8)*4(r10)
   2997	ld	r11,(0x80 + 8)*5(r10)
   2998	ld	r11,(0x80 + 8)*6(r10)
   2999	ld	r11,(0x80 + 8)*7(r10)
   3000	addi	r10,r10,0x80*8
   3001	bdnz	1b
   3002
   3003	mtctr	r9
   3004	li	r9,0
   3005	li	r10,0
   3006	li	r11,0
   3007	mr	r1,r8
   3008	mr	r13,r7
   3009	RFSCV
   3010
   3011USE_TEXT_SECTION()
   3012
   3013#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
   3014kvm_interrupt:
   3015	/*
   3016	 * The conditional branch in KVMTEST can't reach all the way,
   3017	 * make a stub.
   3018	 */
   3019	b	kvmppc_interrupt
   3020#endif
   3021
   3022_GLOBAL(do_uaccess_flush)
   3023	UACCESS_FLUSH_FIXUP_SECTION
   3024	nop
   3025	nop
   3026	nop
   3027	blr
   3028	L1D_DISPLACEMENT_FLUSH
   3029	blr
   3030_ASM_NOKPROBE_SYMBOL(do_uaccess_flush)
   3031EXPORT_SYMBOL(do_uaccess_flush)
   3032
   3033
   3034MASKED_INTERRUPT
   3035MASKED_INTERRUPT hsrr=1
   3036
   3037	/*
   3038	 * Relocation-on interrupts: A subset of the interrupts can be delivered
   3039	 * with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering
   3040	 * it.  Addresses are the same as the original interrupt addresses, but
   3041	 * offset by 0xc000000000004000.
   3042	 * It's impossible to receive interrupts below 0x300 via this mechanism.
   3043	 * KVM: None of these traps are from the guest ; anything that escalated
   3044	 * to HV=1 from HV=0 is delivered via real mode handlers.
   3045	 */
   3046
   3047	/*
   3048	 * This uses the standard macro, since the original 0x300 vector
   3049	 * only has extra guff for STAB-based processors -- which never
   3050	 * come here.
   3051	 */
   3052
   3053USE_FIXED_SECTION(virt_trampolines)
   3054	/*
   3055	 * All code below __end_soft_masked is treated as soft-masked. If
   3056	 * any code runs here with MSR[EE]=1, it must then cope with pending
   3057	 * soft interrupt being raised (i.e., by ensuring it is replayed).
   3058	 *
   3059	 * The __end_interrupts marker must be past the out-of-line (OOL)
   3060	 * handlers, so that they are copied to real address 0x100 when running
   3061	 * a relocatable kernel. This ensures they can be reached from the short
   3062	 * trampoline handlers (like 0x4f00, 0x4f20, etc.) which branch
   3063	 * directly, without using LOAD_HANDLER().
   3064	 */
   3065	.align	7
   3066	.globl	__end_interrupts
   3067__end_interrupts:
   3068DEFINE_FIXED_SYMBOL(__end_interrupts, virt_trampolines)
   3069
   3070CLOSE_FIXED_SECTION(real_vectors);
   3071CLOSE_FIXED_SECTION(real_trampolines);
   3072CLOSE_FIXED_SECTION(virt_vectors);
   3073CLOSE_FIXED_SECTION(virt_trampolines);
   3074
   3075USE_TEXT_SECTION()
   3076
   3077/* MSR[RI] should be clear because this uses SRR[01] */
   3078enable_machine_check:
   3079	mflr	r0
   3080	bcl	20,31,$+4
   30810:	mflr	r3
   3082	addi	r3,r3,(1f - 0b)
   3083	mtspr	SPRN_SRR0,r3
   3084	mfmsr	r3
   3085	ori	r3,r3,MSR_ME
   3086	mtspr	SPRN_SRR1,r3
   3087	RFI_TO_KERNEL
   30881:	mtlr	r0
   3089	blr
   3090
   3091/* MSR[RI] should be clear because this uses SRR[01] */
   3092disable_machine_check:
   3093	mflr	r0
   3094	bcl	20,31,$+4
   30950:	mflr	r3
   3096	addi	r3,r3,(1f - 0b)
   3097	mtspr	SPRN_SRR0,r3
   3098	mfmsr	r3
   3099	li	r4,MSR_ME
   3100	andc	r3,r3,r4
   3101	mtspr	SPRN_SRR1,r3
   3102	RFI_TO_KERNEL
   31031:	mtlr	r0
   3104	blr