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

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

#include <asm/exception-64s.h>
#include <asm/ptrace.h>

/*
 * We layout physical memory as follows:
 * 0x0000 - 0x00ff : Secondary processor spin code
 * 0x0100 - 0x2fff : pSeries Interrupt prologs
 * 0x3000 - 0x5fff : interrupt support common interrupt prologs
 * 0x6000 - 0x6fff : Initial (CPU0) segment table
 * 0x7000 - 0x7fff : FWNMI data area
 * 0x8000 -        : Early init and support code
 */

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

	.globl system_reset_pSeries;
system_reset_pSeries:
	HMT_MEDIUM;
	SET_SCRATCH0(r13)
#ifdef CONFIG_PPC_P7_NAP
BEGIN_FTR_SECTION
	/* Running native on arch 2.06 or later, check if we are
	 * waking up from nap. We only handle no state loss and
	 * supervisor state loss. We do -not- handle hypervisor
	 * state loss at this time.
	 */
	mfspr	r13,SPRN_SRR1
	rlwinm.	r13,r13,47-31,30,31
	beq	9f

	/* waking up from powersave (nap) state */
	cmpwi	cr1,r13,2
	/* Total loss of HV state is fatal, we could try to use the
	 * PIR to locate a PACA, then use an emergency stack etc...
	 * but for now, let's just stay stuck here
	 */
	bgt	cr1,.
	GET_PACA(r13)

#ifdef CONFIG_KVM_BOOK3S_64_HV
	lbz	r0,PACAPROCSTART(r13)
	cmpwi	r0,0x80
	bne	1f
	li	r0,1
	stb	r0,PACAPROCSTART(r13)
	b	kvm_start_guest
1:
#endif

	beq	cr1,2f
	b	.power7_wakeup_noloss
2:	b	.power7_wakeup_loss
9:
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
#endif /* CONFIG_PPC_P7_NAP */
	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
				 NOTEST, 0x100)

	. = 0x200
machine_check_pSeries_1:
	/* This is moved out of line as it can be patched by FW, but
	 * some code path might still want to branch into the original
	 * vector
	 */
	b	machine_check_pSeries

	. = 0x300
	.globl data_access_pSeries
data_access_pSeries:
	HMT_MEDIUM
	SET_SCRATCH0(r13)
#ifndef CONFIG_POWER4_ONLY
BEGIN_FTR_SECTION
	b	data_access_check_stab
data_access_not_stab:
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_SLB)
#endif
	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, data_access_common, EXC_STD,
				 KVMTEST_PR, 0x300)

	. = 0x380
	.globl data_access_slb_pSeries
data_access_slb_pSeries:
	HMT_MEDIUM
	SET_SCRATCH0(r13)
	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x380)
	std	r3,PACA_EXSLB+EX_R3(r13)
	mfspr	r3,SPRN_DAR
#ifdef __DISABLED__
	/* Keep that around for when we re-implement dynamic VSIDs */
	cmpdi	r3,0
	bge	slb_miss_user_pseries
#endif /* __DISABLED__ */
	mfspr	r12,SPRN_SRR1
#ifndef CONFIG_RELOCATABLE
	b	.slb_miss_realmode
#else
	/*
	 * We can't just use a direct branch to .slb_miss_realmode
	 * because the distance from here to there depends on where
	 * the kernel ends up being put.
	 */
	mfctr	r11
	ld	r10,PACAKBASE(r13)
	LOAD_HANDLER(r10, .slb_miss_realmode)
	mtctr	r10
	bctr
#endif

	STD_EXCEPTION_PSERIES(0x400, 0x400, instruction_access)

	. = 0x480
	.globl instruction_access_slb_pSeries
instruction_access_slb_pSeries:
	HMT_MEDIUM
	SET_SCRATCH0(r13)
	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x480)
	std	r3,PACA_EXSLB+EX_R3(r13)
	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
#ifdef __DISABLED__
	/* Keep that around for when we re-implement dynamic VSIDs */
	cmpdi	r3,0
	bge	slb_miss_user_pseries
#endif /* __DISABLED__ */
	mfspr	r12,SPRN_SRR1
#ifndef CONFIG_RELOCATABLE
	b	.slb_miss_realmode
#else
	mfctr	r11
	ld	r10,PACAKBASE(r13)
	LOAD_HANDLER(r10, .slb_miss_realmode)
	mtctr	r10
	bctr
#endif

	/* We open code these as we can't have a ". = x" (even with
	 * x = "." within a feature section
	 */
	. = 0x500;
	.globl hardware_interrupt_pSeries;
	.globl hardware_interrupt_hv;
hardware_interrupt_pSeries:
hardware_interrupt_hv:
	BEGIN_FTR_SECTION
		_MASKABLE_EXCEPTION_PSERIES(0x502, hardware_interrupt,
					    EXC_HV, SOFTEN_TEST_HV)
		KVM_HANDLER(PACA_EXGEN, EXC_HV, 0x502)
	FTR_SECTION_ELSE
		_MASKABLE_EXCEPTION_PSERIES(0x500, hardware_interrupt,
					    EXC_STD, SOFTEN_TEST_HV_201)
		KVM_HANDLER(PACA_EXGEN, EXC_STD, 0x500)
	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)

	STD_EXCEPTION_PSERIES(0x600, 0x600, alignment)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x600)

	STD_EXCEPTION_PSERIES(0x700, 0x700, program_check)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x700)

	STD_EXCEPTION_PSERIES(0x800, 0x800, fp_unavailable)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x800)

	MASKABLE_EXCEPTION_PSERIES(0x900, 0x900, decrementer)
	MASKABLE_EXCEPTION_HV(0x980, 0x982, decrementer)

	STD_EXCEPTION_PSERIES(0xa00, 0xa00, trap_0a)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xa00)

	STD_EXCEPTION_PSERIES(0xb00, 0xb00, trap_0b)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xb00)

	. = 0xc00
	.globl	system_call_pSeries
system_call_pSeries:
	HMT_MEDIUM
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
	SET_SCRATCH0(r13)
	GET_PACA(r13)
	std	r9,PACA_EXGEN+EX_R9(r13)
	std	r10,PACA_EXGEN+EX_R10(r13)
	mfcr	r9
	KVMTEST(0xc00)
	GET_SCRATCH0(r13)
#endif
BEGIN_FTR_SECTION
	cmpdi	r0,0x1ebe
	beq-	1f
END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
	mr	r9,r13
	GET_PACA(r13)
	mfspr	r11,SPRN_SRR0
	mfspr	r12,SPRN_SRR1
	ld	r10,PACAKBASE(r13)
	LOAD_HANDLER(r10, system_call_entry)
	mtspr	SPRN_SRR0,r10
	ld	r10,PACAKMSR(r13)
	mtspr	SPRN_SRR1,r10
	rfid
	b	.	/* prevent speculative execution */

	KVM_HANDLER(PACA_EXGEN, EXC_STD, 0xc00)

/* Fast LE/BE switch system call */
1:	mfspr	r12,SPRN_SRR1
	xori	r12,r12,MSR_LE
	mtspr	SPRN_SRR1,r12
	rfid		/* return to userspace */
	b	.

	STD_EXCEPTION_PSERIES(0xd00, 0xd00, single_step)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xd00)

	/* At 0xe??? we have a bunch of hypervisor exceptions, we branch
	 * out of line to handle them
	 */
	. = 0xe00
	b	h_data_storage_hv
	. = 0xe20
	b	h_instr_storage_hv
	. = 0xe40
	b	emulation_assist_hv
	. = 0xe50
	b	hmi_exception_hv
	. = 0xe60
	b	hmi_exception_hv

	/* We need to deal with the Altivec unavailable exception
	 * here which is at 0xf20, thus in the middle of the
	 * prolog code of the PerformanceMonitor one. A little
	 * trickery is thus necessary
	 */
performance_monitor_pSeries_1:
	. = 0xf00
	b	performance_monitor_pSeries

altivec_unavailable_pSeries_1:
	. = 0xf20
	b	altivec_unavailable_pSeries

vsx_unavailable_pSeries_1:
	. = 0xf40
	b	vsx_unavailable_pSeries

#ifdef CONFIG_CBE_RAS
	STD_EXCEPTION_HV(0x1200, 0x1202, cbe_system_error)
	KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0x1202)
#endif /* CONFIG_CBE_RAS */

	STD_EXCEPTION_PSERIES(0x1300, 0x1300, instruction_breakpoint)
	KVM_HANDLER_PR_SKIP(PACA_EXGEN, EXC_STD, 0x1300)

#ifdef CONFIG_CBE_RAS
	STD_EXCEPTION_HV(0x1600, 0x1602, cbe_maintenance)
	KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0x1602)
#endif /* CONFIG_CBE_RAS */

	STD_EXCEPTION_PSERIES(0x1700, 0x1700, altivec_assist)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x1700)

#ifdef CONFIG_CBE_RAS
	STD_EXCEPTION_HV(0x1800, 0x1802, cbe_thermal)
	KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0x1802)
#endif /* CONFIG_CBE_RAS */

	. = 0x3000

/*** Out of line interrupts support ***/

	/* moved from 0x200 */
machine_check_pSeries:
	.globl machine_check_fwnmi
machine_check_fwnmi:
	HMT_MEDIUM
	SET_SCRATCH0(r13)		/* save r13 */
	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common,
				 EXC_STD, KVMTEST, 0x200)
	KVM_HANDLER_SKIP(PACA_EXMC, EXC_STD, 0x200)

#ifndef CONFIG_POWER4_ONLY
	/* moved from 0x300 */
data_access_check_stab:
	GET_PACA(r13)
	std	r9,PACA_EXSLB+EX_R9(r13)
	std	r10,PACA_EXSLB+EX_R10(r13)
	mfspr	r10,SPRN_DAR
	mfspr	r9,SPRN_DSISR
	srdi	r10,r10,60
	rlwimi	r10,r9,16,0x20
#ifdef CONFIG_KVM_BOOK3S_PR
	lbz	r9,HSTATE_IN_GUEST(r13)
	rlwimi	r10,r9,8,0x300
#endif
	mfcr	r9
	cmpwi	r10,0x2c
	beq	do_stab_bolted_pSeries
	mtcrf	0x80,r9
	ld	r9,PACA_EXSLB+EX_R9(r13)
	ld	r10,PACA_EXSLB+EX_R10(r13)
	b	data_access_not_stab
do_stab_bolted_pSeries:
	std	r11,PACA_EXSLB+EX_R11(r13)
	std	r12,PACA_EXSLB+EX_R12(r13)
	GET_SCRATCH0(r10)
	std	r10,PACA_EXSLB+EX_R13(r13)
	EXCEPTION_PROLOG_PSERIES_1(.do_stab_bolted, EXC_STD)
#endif /* CONFIG_POWER4_ONLY */

	KVM_HANDLER_PR_SKIP(PACA_EXGEN, EXC_STD, 0x300)
	KVM_HANDLER_PR_SKIP(PACA_EXSLB, EXC_STD, 0x380)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x400)
	KVM_HANDLER_PR(PACA_EXSLB, EXC_STD, 0x480)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x900)
	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0x982)

	.align	7
	/* moved from 0xe00 */
	STD_EXCEPTION_HV(., 0xe02, h_data_storage)
	KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0xe02)
	STD_EXCEPTION_HV(., 0xe22, h_instr_storage)
	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe22)
	STD_EXCEPTION_HV(., 0xe42, emulation_assist)
	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe42)
	STD_EXCEPTION_HV(., 0xe62, hmi_exception) /* need to flush cache ? */
	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe62)

	/* moved from 0xf00 */
	STD_EXCEPTION_PSERIES(., 0xf00, performance_monitor)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf00)
	STD_EXCEPTION_PSERIES(., 0xf20, altivec_unavailable)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf20)
	STD_EXCEPTION_PSERIES(., 0xf40, vsx_unavailable)
	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf40)

/*
 * An interrupt came in while soft-disabled; clear EE in SRR1,
 * clear paca->hard_enabled and return.
 */
masked_interrupt:
	stb	r10,PACAHARDIRQEN(r13)
	mtcrf	0x80,r9
	ld	r9,PACA_EXGEN+EX_R9(r13)
	mfspr	r10,SPRN_SRR1
	rldicl	r10,r10,48,1		/* clear MSR_EE */
	rotldi	r10,r10,16
	mtspr	SPRN_SRR1,r10
	ld	r10,PACA_EXGEN+EX_R10(r13)
	GET_SCRATCH0(r13)
	rfid
	b	.

masked_Hinterrupt:
	stb	r10,PACAHARDIRQEN(r13)
	mtcrf	0x80,r9
	ld	r9,PACA_EXGEN+EX_R9(r13)
	mfspr	r10,SPRN_HSRR1
	rldicl	r10,r10,48,1		/* clear MSR_EE */
	rotldi	r10,r10,16
	mtspr	SPRN_HSRR1,r10
	ld	r10,PACA_EXGEN+EX_R10(r13)
	GET_SCRATCH0(r13)
	hrfid
	b	.

#ifdef CONFIG_PPC_PSERIES
/*
 * Vectors for the FWNMI option.  Share common code.
 */
	.globl system_reset_fwnmi
      .align 7
system_reset_fwnmi:
	HMT_MEDIUM
	SET_SCRATCH0(r13)		/* save r13 */
	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
				 NOTEST, 0x100)

#endif /* CONFIG_PPC_PSERIES */

#ifdef __DISABLED__
/*
 * This is used for when the SLB miss handler has to go virtual,
 * which doesn't happen for now anymore but will once we re-implement
 * dynamic VSIDs for shared page tables
 */
slb_miss_user_pseries:
	std	r10,PACA_EXGEN+EX_R10(r13)
	std	r11,PACA_EXGEN+EX_R11(r13)
	std	r12,PACA_EXGEN+EX_R12(r13)
	GET_SCRATCH0(r10)
	ld	r11,PACA_EXSLB+EX_R9(r13)
	ld	r12,PACA_EXSLB+EX_R3(r13)
	std	r10,PACA_EXGEN+EX_R13(r13)
	std	r11,PACA_EXGEN+EX_R9(r13)
	std	r12,PACA_EXGEN+EX_R3(r13)
	clrrdi	r12,r13,32
	mfmsr	r10
	mfspr	r11,SRR0			/* save SRR0 */
	ori	r12,r12,slb_miss_user_common@l	/* virt addr of handler */
	ori	r10,r10,MSR_IR|MSR_DR|MSR_RI
	mtspr	SRR0,r12
	mfspr	r12,SRR1			/* and SRR1 */
	mtspr	SRR1,r10
	rfid
	b	.				/* prevent spec. execution */
#endif /* __DISABLED__ */

	.align	7
	.globl	__end_interrupts
__end_interrupts:

/*
 * Code from here down to __end_handlers is invoked from the
 * exception prologs above.  Because the prologs assemble the
 * addresses of these handlers using the LOAD_HANDLER macro,
 * which uses an addi instruction, these handlers must be in
 * the first 32k of the kernel image.
 */

/*** Common interrupt handlers ***/

	STD_EXCEPTION_COMMON(0x100, system_reset, .system_reset_exception)

	/*
	 * Machine check is different because we use a different
	 * save area: PACA_EXMC instead of PACA_EXGEN.
	 */
	.align	7
	.globl machine_check_common
machine_check_common:
	EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
	FINISH_NAP
	DISABLE_INTS
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.machine_check_exception
	b	.ret_from_except

	STD_EXCEPTION_COMMON_ASYNC(0x500, hardware_interrupt, do_IRQ)
	STD_EXCEPTION_COMMON_ASYNC(0x900, decrementer, .timer_interrupt)
	STD_EXCEPTION_COMMON(0xa00, trap_0a, .unknown_exception)
	STD_EXCEPTION_COMMON(0xb00, trap_0b, .unknown_exception)
	STD_EXCEPTION_COMMON(0xd00, single_step, .single_step_exception)
	STD_EXCEPTION_COMMON(0xe00, trap_0e, .unknown_exception)
        STD_EXCEPTION_COMMON(0xe40, emulation_assist, .program_check_exception)
        STD_EXCEPTION_COMMON(0xe60, hmi_exception, .unknown_exception)
	STD_EXCEPTION_COMMON_ASYNC(0xf00, performance_monitor, .performance_monitor_exception)
	STD_EXCEPTION_COMMON(0x1300, instruction_breakpoint, .instruction_breakpoint_exception)
#ifdef CONFIG_ALTIVEC
	STD_EXCEPTION_COMMON(0x1700, altivec_assist, .altivec_assist_exception)
#else
	STD_EXCEPTION_COMMON(0x1700, altivec_assist, .unknown_exception)
#endif
#ifdef CONFIG_CBE_RAS
	STD_EXCEPTION_COMMON(0x1200, cbe_system_error, .cbe_system_error_exception)
	STD_EXCEPTION_COMMON(0x1600, cbe_maintenance, .cbe_maintenance_exception)
	STD_EXCEPTION_COMMON(0x1800, cbe_thermal, .cbe_thermal_exception)
#endif /* CONFIG_CBE_RAS */

	.align	7
system_call_entry:
	b	system_call_common

ppc64_runlatch_on_trampoline:
	b	.__ppc64_runlatch_on

/*
 * Here we have detected that the kernel stack pointer is bad.
 * R9 contains the saved CR, r13 points to the paca,
 * r10 contains the (bad) kernel stack pointer,
 * r11 and r12 contain the saved SRR0 and SRR1.
 * We switch to using an emergency stack, save the registers there,
 * and call kernel_bad_stack(), which panics.
 */
bad_stack:
	ld	r1,PACAEMERGSP(r13)
	subi	r1,r1,64+INT_FRAME_SIZE
	std	r9,_CCR(r1)
	std	r10,GPR1(r1)
	std	r11,_NIP(r1)
	std	r12,_MSR(r1)
	mfspr	r11,SPRN_DAR
	mfspr	r12,SPRN_DSISR
	std	r11,_DAR(r1)
	std	r12,_DSISR(r1)
	mflr	r10
	mfctr	r11
	mfxer	r12
	std	r10,_LINK(r1)
	std	r11,_CTR(r1)
	std	r12,_XER(r1)
	SAVE_GPR(0,r1)
	SAVE_GPR(2,r1)
	ld	r10,EX_R3(r3)
	std	r10,GPR3(r1)
	SAVE_GPR(4,r1)
	SAVE_4GPRS(5,r1)
	ld	r9,EX_R9(r3)
	ld	r10,EX_R10(r3)
	SAVE_2GPRS(9,r1)
	ld	r9,EX_R11(r3)
	ld	r10,EX_R12(r3)
	ld	r11,EX_R13(r3)
	std	r9,GPR11(r1)
	std	r10,GPR12(r1)
	std	r11,GPR13(r1)
BEGIN_FTR_SECTION
	ld	r10,EX_CFAR(r3)
	std	r10,ORIG_GPR3(r1)
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
	SAVE_8GPRS(14,r1)
	SAVE_10GPRS(22,r1)
	lhz	r12,PACA_TRAP_SAVE(r13)
	std	r12,_TRAP(r1)
	addi	r11,r1,INT_FRAME_SIZE
	std	r11,0(r1)
	li	r12,0
	std	r12,0(r11)
	ld	r2,PACATOC(r13)
	ld	r11,exception_marker@toc(r2)
	std	r12,RESULT(r1)
	std	r11,STACK_FRAME_OVERHEAD-16(r1)
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.kernel_bad_stack
	b	1b

/*
 * Here r13 points to the paca, r9 contains the saved CR,
 * SRR0 and SRR1 are saved in r11 and r12,
 * r9 - r13 are saved in paca->exgen.
 */
	.align	7
	.globl data_access_common
data_access_common:
	mfspr	r10,SPRN_DAR
	std	r10,PACA_EXGEN+EX_DAR(r13)
	mfspr	r10,SPRN_DSISR
	stw	r10,PACA_EXGEN+EX_DSISR(r13)
	EXCEPTION_PROLOG_COMMON(0x300, PACA_EXGEN)
	DISABLE_INTS
	ld	r12,_MSR(r1)
	ld	r3,PACA_EXGEN+EX_DAR(r13)
	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
	li	r5,0x300
	b	.do_hash_page	 	/* Try to handle as hpte fault */

	.align  7
        .globl  h_data_storage_common
h_data_storage_common:
        mfspr   r10,SPRN_HDAR
        std     r10,PACA_EXGEN+EX_DAR(r13)
        mfspr   r10,SPRN_HDSISR
        stw     r10,PACA_EXGEN+EX_DSISR(r13)
        EXCEPTION_PROLOG_COMMON(0xe00, PACA_EXGEN)
        bl      .save_nvgprs
	DISABLE_INTS
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      .unknown_exception
        b       .ret_from_except

	.align	7
	.globl instruction_access_common
instruction_access_common:
	EXCEPTION_PROLOG_COMMON(0x400, PACA_EXGEN)
	DISABLE_INTS
	ld	r12,_MSR(r1)
	ld	r3,_NIP(r1)
	andis.	r4,r12,0x5820
	li	r5,0x400
	b	.do_hash_page		/* Try to handle as hpte fault */

        STD_EXCEPTION_COMMON(0xe20, h_instr_storage, .unknown_exception)

/*
 * Here is the common SLB miss user that is used when going to virtual
 * mode for SLB misses, that is currently not used
 */
#ifdef __DISABLED__
	.align	7
	.globl	slb_miss_user_common
slb_miss_user_common:
	mflr	r10
	std	r3,PACA_EXGEN+EX_DAR(r13)
	stw	r9,PACA_EXGEN+EX_CCR(r13)
	std	r10,PACA_EXGEN+EX_LR(r13)
	std	r11,PACA_EXGEN+EX_SRR0(r13)
	bl	.slb_allocate_user

	ld	r10,PACA_EXGEN+EX_LR(r13)
	ld	r3,PACA_EXGEN+EX_R3(r13)
	lwz	r9,PACA_EXGEN+EX_CCR(r13)
	ld	r11,PACA_EXGEN+EX_SRR0(r13)
	mtlr	r10
	beq-	slb_miss_fault

	andi.	r10,r12,MSR_RI		/* check for unrecoverable exception */
	beq-	unrecov_user_slb
	mfmsr	r10

.machine push
.machine "power4"
	mtcrf	0x80,r9
.machine pop

	clrrdi	r10,r10,2		/* clear RI before setting SRR0/1 */
	mtmsrd	r10,1

	mtspr	SRR0,r11
	mtspr	SRR1,r12

	ld	r9,PACA_EXGEN+EX_R9(r13)
	ld	r10,PACA_EXGEN+EX_R10(r13)
	ld	r11,PACA_EXGEN+EX_R11(r13)
	ld	r12,PACA_EXGEN+EX_R12(r13)
	ld	r13,PACA_EXGEN+EX_R13(r13)
	rfid
	b	.

slb_miss_fault:
	EXCEPTION_PROLOG_COMMON(0x380, PACA_EXGEN)
	ld	r4,PACA_EXGEN+EX_DAR(r13)
	li	r5,0
	std	r4,_DAR(r1)
	std	r5,_DSISR(r1)
	b	handle_page_fault

unrecov_user_slb:
	EXCEPTION_PROLOG_COMMON(0x4200, PACA_EXGEN)
	DISABLE_INTS
	bl	.save_nvgprs
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.unrecoverable_exception
	b	1b

#endif /* __DISABLED__ */


/*
 * r13 points to the PACA, r9 contains the saved CR,
 * r12 contain the saved SRR1, SRR0 is still ready for return
 * r3 has the faulting address
 * r9 - r13 are saved in paca->exslb.
 * r3 is saved in paca->slb_r3
 * We assume we aren't going to take any exceptions during this procedure.
 */
_GLOBAL(slb_miss_realmode)
	mflr	r10
#ifdef CONFIG_RELOCATABLE
	mtctr	r11
#endif

	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */

	bl	.slb_allocate_realmode

	/* All done -- return from exception. */

	ld	r10,PACA_EXSLB+EX_LR(r13)
	ld	r3,PACA_EXSLB+EX_R3(r13)
	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */

	mtlr	r10

	andi.	r10,r12,MSR_RI	/* check for unrecoverable exception */
	beq-	2f

.machine	push
.machine	"power4"
	mtcrf	0x80,r9
	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
.machine	pop

	ld	r9,PACA_EXSLB+EX_R9(r13)
	ld	r10,PACA_EXSLB+EX_R10(r13)
	ld	r11,PACA_EXSLB+EX_R11(r13)
	ld	r12,PACA_EXSLB+EX_R12(r13)
	ld	r13,PACA_EXSLB+EX_R13(r13)
	rfid
	b	.	/* prevent speculative execution */

2:	mfspr	r11,SPRN_SRR0
	ld	r10,PACAKBASE(r13)
	LOAD_HANDLER(r10,unrecov_slb)
	mtspr	SPRN_SRR0,r10
	ld	r10,PACAKMSR(r13)
	mtspr	SPRN_SRR1,r10
	rfid
	b	.

unrecov_slb:
	EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
	DISABLE_INTS
	bl	.save_nvgprs
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.unrecoverable_exception
	b	1b


#ifdef CONFIG_PPC_970_NAP
power4_fixup_nap:
	andc	r9,r9,r10
	std	r9,TI_LOCAL_FLAGS(r11)
	ld	r10,_LINK(r1)		/* make idle task do the */
	std	r10,_NIP(r1)		/* equivalent of a blr */
	blr
#endif

	.align	7
	.globl alignment_common
alignment_common:
	mfspr	r10,SPRN_DAR
	std	r10,PACA_EXGEN+EX_DAR(r13)
	mfspr	r10,SPRN_DSISR
	stw	r10,PACA_EXGEN+EX_DSISR(r13)
	EXCEPTION_PROLOG_COMMON(0x600, PACA_EXGEN)
	ld	r3,PACA_EXGEN+EX_DAR(r13)
	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
	std	r3,_DAR(r1)
	std	r4,_DSISR(r1)
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	ENABLE_INTS
	bl	.alignment_exception
	b	.ret_from_except

	.align	7
	.globl program_check_common
program_check_common:
	EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN)
	bl	.save_nvgprs
	DISABLE_INTS
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.program_check_exception
	b	.ret_from_except

	.align	7
	.globl fp_unavailable_common
fp_unavailable_common:
	EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)
	bne	1f			/* if from user, just load it up */
	bl	.save_nvgprs
	DISABLE_INTS
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.kernel_fp_unavailable_exception
	BUG_OPCODE
1:	bl	.load_up_fpu
	b	fast_exception_return

	.align	7
	.globl altivec_unavailable_common
altivec_unavailable_common:
	EXCEPTION_PROLOG_COMMON(0xf20, PACA_EXGEN)
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
	beq	1f
	bl	.load_up_altivec
	b	fast_exception_return
1:
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
	bl	.save_nvgprs
	DISABLE_INTS
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.altivec_unavailable_exception
	b	.ret_from_except

	.align	7
	.globl vsx_unavailable_common
vsx_unavailable_common:
	EXCEPTION_PROLOG_COMMON(0xf40, PACA_EXGEN)
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
	bne	.load_up_vsx
1:
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
	bl	.save_nvgprs
	DISABLE_INTS
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.vsx_unavailable_exception
	b	.ret_from_except

	.align	7
	.globl	__end_handlers
__end_handlers:

/*
 * Return from an exception with minimal checks.
 * The caller is assumed to have done EXCEPTION_PROLOG_COMMON.
 * If interrupts have been enabled, or anything has been
 * done that might have changed the scheduling status of
 * any task or sent any task a signal, you should use
 * ret_from_except or ret_from_except_lite instead of this.
 */
fast_exc_return_irq:			/* restores irq state too */
	ld	r3,SOFTE(r1)
	TRACE_AND_RESTORE_IRQ(r3);
	ld	r12,_MSR(r1)
	rldicl	r4,r12,49,63		/* get MSR_EE to LSB */
	stb	r4,PACAHARDIRQEN(r13)	/* restore paca->hard_enabled */
	b	1f

	.globl	fast_exception_return
fast_exception_return:
	ld	r12,_MSR(r1)
1:	ld	r11,_NIP(r1)
	andi.	r3,r12,MSR_RI		/* check if RI is set */
	beq-	unrecov_fer

#ifdef CONFIG_VIRT_CPU_ACCOUNTING
	andi.	r3,r12,MSR_PR
	beq	2f
	ACCOUNT_CPU_USER_EXIT(r3, r4)
2:
#endif

	ld	r3,_CCR(r1)
	ld	r4,_LINK(r1)
	ld	r5,_CTR(r1)
	ld	r6,_XER(r1)
	mtcr	r3
	mtlr	r4
	mtctr	r5
	mtxer	r6
	REST_GPR(0, r1)
	REST_8GPRS(2, r1)

	ld	r10,PACAKMSR(r13)
	clrrdi	r10,r10,2		/* clear RI */
	mtmsrd	r10,1

	mtspr	SPRN_SRR1,r12
	mtspr	SPRN_SRR0,r11
	REST_4GPRS(10, r1)
	ld	r1,GPR1(r1)
	rfid
	b	.	/* prevent speculative execution */

unrecov_fer:
	bl	.save_nvgprs
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.unrecoverable_exception
	b	1b


/*
 * Hash table stuff
 */
	.align	7
_STATIC(do_hash_page)
	std	r3,_DAR(r1)
	std	r4,_DSISR(r1)

	andis.	r0,r4,0xa410		/* weird error? */
	bne-	handle_page_fault	/* if not, try to insert a HPTE */
	andis.  r0,r4,DSISR_DABRMATCH@h
	bne-    handle_dabr_fault

BEGIN_FTR_SECTION
	andis.	r0,r4,0x0020		/* Is it a segment table fault? */
	bne-	do_ste_alloc		/* If so handle it */
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_SLB)

	clrrdi	r11,r1,THREAD_SHIFT
	lwz	r0,TI_PREEMPT(r11)	/* If we're in an "NMI" */
	andis.	r0,r0,NMI_MASK@h	/* (i.e. an irq when soft-disabled) */
	bne	77f			/* then don't call hash_page now */
	/*
	 * We need to set the _PAGE_USER bit if MSR_PR is set or if we are
	 * accessing a userspace segment (even from the kernel). We assume
	 * kernel addresses always have the high bit set.
	 */
	rlwinm	r4,r4,32-25+9,31-9,31-9	/* DSISR_STORE -> _PAGE_RW */
	rotldi	r0,r3,15		/* Move high bit into MSR_PR posn */
	orc	r0,r12,r0		/* MSR_PR | ~high_bit */
	rlwimi	r4,r0,32-13,30,30	/* becomes _PAGE_USER access bit */
	ori	r4,r4,1			/* add _PAGE_PRESENT */
	rlwimi	r4,r5,22+2,31-2,31-2	/* Set _PAGE_EXEC if trap is 0x400 */

	/*
	 * r3 contains the faulting address
	 * r4 contains the required access permissions
	 * r5 contains the trap number
	 *
	 * at return r3 = 0 for success
	 */
	bl	.hash_page		/* build HPTE if possible */
	cmpdi	r3,0			/* see if hash_page succeeded */

	/*
	 * Here we have interrupts hard-disabled, so it is sufficient
	 * to restore paca->{soft,hard}_enable and get out.
	 */
	beq	fast_exc_return_irq	/* Return from exception on success */

	/* For a hash failure, we don't bother re-enabling interrupts */
	ble-	13f

/* Here we have a page fault that hash_page can't handle. */
handle_page_fault:
11:	ld	r4,_DAR(r1)
	ld	r5,_DSISR(r1)
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.do_page_fault
	cmpdi	r3,0
	beq+	12f
	bl	.save_nvgprs
	mr	r5,r3
	addi	r3,r1,STACK_FRAME_OVERHEAD
	lwz	r4,_DAR(r1)
	bl	.bad_page_fault
	b	.ret_from_except

/* We have a data breakpoint exception - handle it */
handle_dabr_fault:
	bl	.save_nvgprs
	ld      r4,_DAR(r1)
	ld      r5,_DSISR(r1)
	addi    r3,r1,STACK_FRAME_OVERHEAD
	bl      .do_dabr
12:	b       .ret_from_except_lite


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

/*
 * We come here as a result of a DSI at a point where we don't want
 * to call hash_page, such as when we are accessing memory (possibly
 * user memory) inside a PMU interrupt that occurred while interrupts
 * were soft-disabled.  We want to invoke the exception handler for
 * the access, or panic if there isn't a handler.
 */
77:	bl	.save_nvgprs
	mr	r4,r3
	addi	r3,r1,STACK_FRAME_OVERHEAD
	li	r5,SIGSEGV
	bl	.bad_page_fault
	b	.ret_from_except

	/* here we have a segment miss */
do_ste_alloc:
	bl	.ste_allocate		/* try to insert stab entry */
	cmpdi	r3,0
	bne-	handle_page_fault
	b	fast_exception_return

/*
 * r13 points to the PACA, r9 contains the saved CR,
 * r11 and r12 contain the saved SRR0 and SRR1.
 * r9 - r13 are saved in paca->exslb.
 * We assume we aren't going to take any exceptions during this procedure.
 * We assume (DAR >> 60) == 0xc.
 */
	.align	7
_GLOBAL(do_stab_bolted)
	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
	std	r11,PACA_EXSLB+EX_SRR0(r13)	/* save SRR0 in exc. frame */

	/* Hash to the primary group */
	ld	r10,PACASTABVIRT(r13)
	mfspr	r11,SPRN_DAR
	srdi	r11,r11,28
	rldimi	r10,r11,7,52	/* r10 = first ste of the group */

	/* Calculate VSID */
	/* This is a kernel address, so protovsid = ESID */
	ASM_VSID_SCRAMBLE(r11, r9, 256M)
	rldic	r9,r11,12,16	/* r9 = vsid << 12 */

	/* Search the primary group for a free entry */
1:	ld	r11,0(r10)	/* Test valid bit of the current ste	*/
	andi.	r11,r11,0x80
	beq	2f
	addi	r10,r10,16
	andi.	r11,r10,0x70
	bne	1b

	/* Stick for only searching the primary group for now.		*/
	/* At least for now, we use a very simple random castout scheme */
	/* Use the TB as a random number ;  OR in 1 to avoid entry 0	*/
	mftb	r11
	rldic	r11,r11,4,57	/* r11 = (r11 << 4) & 0x70 */
	ori	r11,r11,0x10

	/* r10 currently points to an ste one past the group of interest */
	/* make it point to the randomly selected entry			*/
	subi	r10,r10,128
	or 	r10,r10,r11	/* r10 is the entry to invalidate	*/

	isync			/* mark the entry invalid		*/
	ld	r11,0(r10)
	rldicl	r11,r11,56,1	/* clear the valid bit */
	rotldi	r11,r11,8
	std	r11,0(r10)
	sync

	clrrdi	r11,r11,28	/* Get the esid part of the ste		*/
	slbie	r11

2:	std	r9,8(r10)	/* Store the vsid part of the ste	*/
	eieio

	mfspr	r11,SPRN_DAR		/* Get the new esid			*/
	clrrdi	r11,r11,28	/* Permits a full 32b of ESID		*/
	ori	r11,r11,0x90	/* Turn on valid and kp			*/
	std	r11,0(r10)	/* Put new entry back into the stab	*/

	sync

	/* All done -- return from exception. */
	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
	ld	r11,PACA_EXSLB+EX_SRR0(r13)	/* get saved SRR0 */

	andi.	r10,r12,MSR_RI
	beq-	unrecov_slb

	mtcrf	0x80,r9			/* restore CR */

	mfmsr	r10
	clrrdi	r10,r10,2
	mtmsrd	r10,1

	mtspr	SPRN_SRR0,r11
	mtspr	SPRN_SRR1,r12
	ld	r9,PACA_EXSLB+EX_R9(r13)
	ld	r10,PACA_EXSLB+EX_R10(r13)
	ld	r11,PACA_EXSLB+EX_R11(r13)
	ld	r12,PACA_EXSLB+EX_R12(r13)
	ld	r13,PACA_EXSLB+EX_R13(r13)
	rfid
	b	.	/* prevent speculative execution */

#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
/*
 * Data area reserved for FWNMI option.
 * This address (0x7000) is fixed by the RPA.
 */
	.= 0x7000
	.globl fwnmi_data_area
fwnmi_data_area:

	/* pseries and powernv need to keep the whole page from
	 * 0x7000 to 0x8000 free for use by the firmware
	 */
        . = 0x8000
#endif /* defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV) */

/* Space for CPU0's segment table */
	.balign 4096
	.globl initial_stab
initial_stab:
	.space	4096

#ifdef CONFIG_PPC_POWERNV
_GLOBAL(opal_mc_secondary_handler)
	HMT_MEDIUM
	SET_SCRATCH0(r13)
	GET_PACA(r13)
	clrldi	r3,r3,2
	tovirt(r3,r3)
	std	r3,PACA_OPAL_MC_EVT(r13)
	ld	r13,OPAL_MC_SRR0(r3)
	mtspr	SPRN_SRR0,r13
	ld	r13,OPAL_MC_SRR1(r3)
	mtspr	SPRN_SRR1,r13
	ld	r3,OPAL_MC_GPR3(r3)
	GET_SCRATCH0(r13)
	b	machine_check_pSeries
#endif /* CONFIG_PPC_POWERNV */