path: root/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/hw_irq.h>
#include <asm/exception-64s.h>
#include <asm/ptrace.h>

/*
 * We layout physical memory as follows:
 * 0x0000 - 0x00ff : Secondary processor spin code
 * 0x0100 - 0x17ff : pSeries Interrupt prologs
 * 0x1800 - 0x4000 : interrupt support common interrupt prologs
 * 0x4000 - 0x5fff : pSeries interrupts with IR=1,DR=1
 * 0x6000 - 0x6fff : more interrupt support including for IR=1,DR=1
 * 0x7000 - 0x7fff : FWNMI data area
 * 0x8000 - 0x8fff : Initial (CPU0) segment table
 * 0x9000 -        : Early init and support code
 */
	/* Syscall routine is used twice, in reloc-off and reloc-on paths */
#define SYSCALL_PSERIES_1 					\
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 ;					\
0:

#define SYSCALL_PSERIES_2_RFID 					\
	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 */

#define SYSCALL_PSERIES_3					\
	/* 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	. ;						\
2:	mfspr	r12,SPRN_SRR1 ;					\
	andi.	r12,r12,MSR_PR ;				\
	bne	0b ;						\
	mtspr	SPRN_SRR0,r3 ;					\
	mtspr	SPRN_SRR1,r4 ;					\
	mtspr	SPRN_SDR1,r5 ;					\
	rfid ;							\
	b	. ;	/* prevent speculative execution */

#if defined(CONFIG_RELOCATABLE)
	/*
	 * We can't branch directly; in the direct case we use LR
	 * and system_call_entry restores LR.  (We thus need to move
	 * LR to r10 in the RFID case too.)
	 */
#define SYSCALL_PSERIES_2_DIRECT				\
	mflr	r10 ;						\
	ld	r12,PACAKBASE(r13) ; 				\
	LOAD_HANDLER(r12, system_call_entry_direct) ;		\
	mtctr	r12 ;						\
	mfspr	r12,SPRN_SRR1 ;					\
	/* Re-use of r13... No spare regs to do this */	\
	li	r13,MSR_RI ;					\
	mtmsrd 	r13,1 ;						\
	GET_PACA(r13) ;	/* get r13 back */			\
	bctr ;
#else
	/* We can branch directly */
#define SYSCALL_PSERIES_2_DIRECT				\
	mfspr	r12,SPRN_SRR1 ;					\
	li	r10,MSR_RI ;					\
	mtmsrd 	r10,1 ;			/* Set RI (EE=0) */	\
	b	system_call_entry_direct ;
#endif

/*
 * 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_PPR_DISCARD
	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_HV_POSSIBLE
	li	r0,KVM_HWTHREAD_IN_KERNEL
	stb	r0,HSTATE_HWTHREAD_STATE(r13)
	/* Order setting hwthread_state vs. testing hwthread_req */
	sync
	lbz	r0,HSTATE_HWTHREAD_REQ(r13)
	cmpwi	r0,0
	beq	1f
	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
	 */
	HMT_MEDIUM_PPR_DISCARD
	SET_SCRATCH0(r13)		/* save r13 */
	EXCEPTION_PROLOG_0(PACA_EXMC)
	b	machine_check_pSeries_0

	. = 0x300
	.globl data_access_pSeries
data_access_pSeries:
	HMT_MEDIUM_PPR_DISCARD
	SET_SCRATCH0(r13)
BEGIN_FTR_SECTION
	b	data_access_check_stab
data_access_not_stab:
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_SLB)
	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, data_access_common, EXC_STD,
				 KVMTEST, 0x300)

	. = 0x380
	.globl data_access_slb_pSeries
data_access_slb_pSeries:
	HMT_MEDIUM_PPR_DISCARD
	SET_SCRATCH0(r13)
	EXCEPTION_PROLOG_0(PACA_EXSLB)
	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST, 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_PPR_DISCARD
	SET_SCRATCH0(r13)
	EXCEPTION_PROLOG_0(PACA_EXSLB)
	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:
	HMT_MEDIUM_PPR_DISCARD
	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_HAN