entry.s

linux 内核源代码

	stdi		gr2,@(gr28,#REG_GR(2))
	stdi		gr4,@(gr28,#REG_GR(4))
	stdi		gr6,@(gr28,#REG_GR(6))
	stdi		gr8,@(gr28,#REG_GR(8))
	stdi		gr10,@(gr28,#REG_GR(10))
	stdi		gr12,@(gr28,#REG_GR(12))
	stdi		gr14,@(gr28,#REG_GR(14))
	stdi		gr16,@(gr28,#REG_GR(16))
	stdi		gr18,@(gr28,#REG_GR(18))
	stdi		gr24,@(gr28,#REG_GR(24))
	stdi		gr26,@(gr28,#REG_GR(26))
	sti		gr29,@(gr28,#REG_GR(29))
	stdi		gr30,@(gr28,#REG_GR(30))

	movsg		lcr ,gr27
	movsg		lr  ,gr26
	movgs		gr23,lr
	movsg		cccr,gr25
	movsg		ccr ,gr24
	movsg		isr ,gr23

	setlos.p	#-1,gr4
	andi		gr22,#PSR_PS,gr5		/* try to rebuild original PSR value */
	andi.p		gr22,#~(PSR_PS|PSR_S),gr6
	slli		gr5,#1,gr5
	or		gr6,gr5,gr5
	andi		gr5,#~PSR_ET,gr5

	sti		gr20,@(gr28,#REG_TBR)
	sti		gr21,@(gr28,#REG_PC)
	sti		gr5 ,@(gr28,#REG_PSR)
	sti		gr23,@(gr28,#REG_ISR)
	stdi		gr24,@(gr28,#REG_CCR)
	stdi		gr26,@(gr28,#REG_LR)
	sti		gr4 ,@(gr28,#REG_SYSCALLNO)

	movsg		iacc0h,gr4
	movsg		iacc0l,gr5
	stdi		gr4,@(gr28,#REG_IACC0)

	movsg		gner0,gr4
	movsg		gner1,gr5
	stdi.p		gr4,@(gr28,#REG_GNER0)

	# set up virtual interrupt disablement
	subicc		gr0,#1,gr0,icc2			/* clear Z flag, set C flag */

	# set up kernel global registers
	sethi.p		%hi(__kernel_current_task),gr5
	setlo		%lo(__kernel_current_task),gr5
	sethi.p		%hi(_gp),gr16
	setlo		%lo(_gp),gr16
	ldi		@(gr5,#0),gr29
	ldi		@(gr29,#4),gr15		; __current_thread_info = current->thread_info

	# switch to the kernel trap table
	sethi.p		%hi(__entry_kerneltrap_table),gr6
	setlo		%lo(__entry_kerneltrap_table),gr6
	movgs		gr6,tbr

	# make sure we (the kernel) get div-zero and misalignment exceptions
	setlos		#ISR_EDE|ISR_DTT_DIVBYZERO|ISR_EMAM_EXCEPTION,gr5
	movgs		gr5,isr

	# clear power-saving mode flags
	movsg		hsr0,gr4
	andi		gr4,#~HSR0_PDM,gr4
	movgs		gr4,hsr0

	# multiplex again using old TBR as a guide
	setlos.p	#TBR_TT,gr3
	sethi		%hi(__entry_vector_table),gr6
	and.p		gr20,gr3,gr5
	setlo		%lo(__entry_vector_table),gr6
	srli		gr5,#2,gr5
	ld		@(gr5,gr6),gr5

	LEDS		0x6009
	jmpl		@(gr5,gr0)


	.size		__entry_common,.-__entry_common

###############################################################################
#
# handle instruction MMU fault
#
###############################################################################
#ifdef CONFIG_MMU
	.globl		__entry_insn_mmu_fault
__entry_insn_mmu_fault:
	LEDS		0x6010
	setlos		#0,gr8
	movsg		esr0,gr9
	movsg		scr2,gr10

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr

	sethi.p		%hi(do_page_fault),gr5
	setlo		%lo(do_page_fault),gr5
	jmpl		@(gr5,gr0)	; call do_page_fault(0,esr0,ear0)
#endif


###############################################################################
#
# handle instruction access error
#
###############################################################################
	.globl		__entry_insn_access_error
__entry_insn_access_error:
	LEDS		0x6011
	sethi.p		%hi(insn_access_error),gr5
	setlo		%lo(insn_access_error),gr5
	movsg		esfr1,gr8
	movsg		epcr0,gr9
	movsg		esr0,gr10

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call insn_access_error(esfr1,epcr0,esr0)

###############################################################################
#
# handle various instructions of dubious legality
#
###############################################################################
	.globl		__entry_unsupported_trap
	.globl		__entry_illegal_instruction
	.globl		__entry_privileged_instruction
	.globl		__entry_debug_exception
__entry_unsupported_trap:
	subi		gr21,#4,gr21
	sti		gr21,@(gr28,#REG_PC)
__entry_illegal_instruction:
__entry_privileged_instruction:
__entry_debug_exception:
	LEDS		0x6012
	sethi.p		%hi(illegal_instruction),gr5
	setlo		%lo(illegal_instruction),gr5
	movsg		esfr1,gr8
	movsg		epcr0,gr9
	movsg		esr0,gr10

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call ill_insn(esfr1,epcr0,esr0)

###############################################################################
#
# handle media exception
#
###############################################################################
	.globl		__entry_media_exception
__entry_media_exception:
	LEDS		0x6013
	sethi.p		%hi(media_exception),gr5
	setlo		%lo(media_exception),gr5
	movsg		msr0,gr8
	movsg		msr1,gr9

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call media_excep(msr0,msr1)

###############################################################################
#
# handle data MMU fault
# handle data DAT fault (write-protect exception)
#
###############################################################################
#ifdef CONFIG_MMU
	.globl		__entry_data_mmu_fault
__entry_data_mmu_fault:
	.globl		__entry_data_dat_fault
__entry_data_dat_fault:
	LEDS		0x6014
	setlos		#1,gr8
	movsg		esr0,gr9
	movsg		scr2,gr10	; saved EAR0

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr

	sethi.p		%hi(do_page_fault),gr5
	setlo		%lo(do_page_fault),gr5
	jmpl		@(gr5,gr0)	; call do_page_fault(1,esr0,ear0)
#endif

###############################################################################
#
# handle data and instruction access exceptions
#
###############################################################################
	.globl		__entry_insn_access_exception
	.globl		__entry_data_access_exception
__entry_insn_access_exception:
__entry_data_access_exception:
	LEDS		0x6016
	sethi.p		%hi(memory_access_exception),gr5
	setlo		%lo(memory_access_exception),gr5
	movsg		esr0,gr8
	movsg		scr2,gr9	; saved EAR0
	movsg		epcr0,gr10

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call memory_access_error(esr0,ear0,epcr0)

###############################################################################
#
# handle data access error
#
###############################################################################
	.globl		__entry_data_access_error
__entry_data_access_error:
	LEDS		0x6016
	sethi.p		%hi(data_access_error),gr5
	setlo		%lo(data_access_error),gr5
	movsg		esfr1,gr8
	movsg		esr15,gr9
	movsg		ear15,gr10

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call data_access_error(esfr1,esr15,ear15)

###############################################################################
#
# handle data store error
#
###############################################################################
	.globl		__entry_data_store_error
__entry_data_store_error:
	LEDS		0x6017
	sethi.p		%hi(data_store_error),gr5
	setlo		%lo(data_store_error),gr5
	movsg		esfr1,gr8
	movsg		esr14,gr9

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call data_store_error(esfr1,esr14)

###############################################################################
#
# handle division exception
#
###############################################################################
	.globl		__entry_division_exception
__entry_division_exception:
	LEDS		0x6018
	sethi.p		%hi(division_exception),gr5
	setlo		%lo(division_exception),gr5
	movsg		esfr1,gr8
	movsg		esr0,gr9
	movsg		isr,gr10

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call div_excep(esfr1,esr0,isr)

###############################################################################
#
# handle compound exception
#
###############################################################################
	.globl		__entry_compound_exception
__entry_compound_exception:
	LEDS		0x6019
	sethi.p		%hi(compound_exception),gr5
	setlo		%lo(compound_exception),gr5
	movsg		esfr1,gr8
	movsg		esr0,gr9
	movsg		esr14,gr10
	movsg		esr15,gr11
	movsg		msr0,gr12
	movsg		msr1,gr13

	# now that we've accessed the exception regs, we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	jmpl		@(gr5,gr0)	; call comp_excep(esfr1,esr0,esr14,esr15,msr0,msr1)

###############################################################################
#
# handle interrupts and NMIs
#
###############################################################################
	.globl		__entry_do_IRQ
__entry_do_IRQ:
	LEDS		0x6020

	# we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	bra		do_IRQ

	.globl		__entry_do_NMI
__entry_do_NMI:
	LEDS		0x6021

	# we can enable exceptions
	movsg		psr,gr4
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr
	bra		do_NMI

###############################################################################
#
# the return path for a newly forked child process
# - __switch_to() saved the old current pointer in GR8 for us
#
###############################################################################
	.globl		ret_from_fork
ret_from_fork:
	LEDS		0x6100
	call		schedule_tail

	# fork & co. return 0 to child
	setlos.p	#0,gr8
	bra		__syscall_exit

###################################################################################################
#
# Return to user mode is not as complex as all this looks,
# but we want the default path for a system call return to
# go as quickly as possible which is why some of this is
# less clear than it otherwise should be.
#
###################################################################################################
	.balign		L1_CACHE_BYTES
	.globl		system_call
system_call:
	LEDS		0x6101
	movsg		psr,gr4			; enable exceptions
	ori		gr4,#PSR_ET,gr4
	movgs		gr4,psr

	sti		gr7,@(gr28,#REG_SYSCALLNO)
	sti.p		gr8,@(gr28,#REG_ORIG_GR8)

	subicc		gr7,#nr_syscalls,gr0,icc0
	bnc		icc0,#0,__syscall_badsys

	ldi		@(gr15,#TI_FLAGS),gr4
	ori		gr4,#_TIF_SYSCALL_TRACE,gr4
	andicc		gr4,#_TIF_SYSCALL_TRACE,gr0,icc0
	bne		icc0,#0,__syscall_trace_entry

__syscall_call:
	slli.p		gr7,#2,gr7
	sethi		%hi(sys_call_table),gr5
	setlo		%lo(sys_call_table),gr5
	ld		@(gr5,gr7),gr4
	calll		@(gr4,gr0)


###############################################################################
#
# return to interrupted process
#
###############################################################################
__syscall_exit:
	LEDS		0x6300

	sti		gr8,@(gr28,#REG_GR(8))	; save return value

	# rebuild saved psr - execve will change it for init/main.c
	ldi		@(gr28,#REG_PSR),gr22
	srli		gr22,#1,gr5
	andi.p		gr22,#~PSR_PS,gr22
	andi		gr5,#PSR_PS,gr5
	or		gr5,gr22,gr22
	ori		gr22,#PSR_S,gr22

	# keep current PSR in GR23
	movsg		psr,gr23

	# make sure we don't miss an interrupt setting need_resched or sigpending between
	# sampling and the RETT
	ori		gr23,#PSR_PIL_14,gr23
	movgs		gr23,psr

	ldi		@(gr15,#TI_FLAGS),gr4
	sethi.p		%hi(_TIF_ALLWORK_MASK),gr5
	setlo		%lo(_TIF_ALLWORK_MASK),gr5
	andcc		gr4,gr5,gr0,icc0
	bne		icc0,#0,__syscall_exit_work

	# restore all registers and return
__entry_return_direct:
	LEDS		0x6301

	andi		gr22,#~PSR_ET,gr22
	movgs		gr22,psr

	ldi		@(gr28,#REG_ISR),gr23
	lddi		@(gr28,#REG_CCR),gr24
	lddi		@(gr28,#REG_LR) ,gr26
	ldi		@(gr28,#REG_PC) ,gr21
	ldi		@(gr28,#REG_TBR),gr20

	movgs		gr20,tbr
	movgs		gr21,pcsr
	movgs		gr23,isr
	movgs		gr24,ccr
	movgs		gr25,cccr
	movgs		gr26,lr
	movgs		gr27,lcr

	lddi		@(gr28,#REG_GNER0),gr4
	movgs		gr4,gner0
	movgs		gr5,gner1

	lddi		@(gr28,#REG_IACC0),gr4
	movgs		gr4,iacc0h
	movgs		gr5,iacc0l

	lddi		@(gr28,#REG_GR(4)) ,gr4
	lddi		@(gr28,#REG_GR(6)) ,gr6
	lddi		@(gr28,#REG_GR(8)) ,gr8
	lddi		@(gr28,#REG_GR(10)),gr10
	lddi		@(gr28,#REG_GR(12)),gr12
	lddi		@(gr28,#REG_GR(14)),gr14
	lddi		@(gr28,#REG_GR(16)),gr16
	lddi		@(gr28,#REG_GR(18)),gr18
	lddi		@(gr28,#REG_GR(20)),gr20
	lddi		@(gr28,#REG_GR(22)),gr22
	lddi		@(gr28,#REG_GR(24)),gr24
	lddi		@(gr28,#REG_GR(26)),gr26
	ldi		@(gr28,#REG_GR(29)),gr29
	lddi		@(gr28,#REG_GR(30)),gr30

	# check to see if a debugging return is required
	LEDS		0x67f0
	movsg		ccr,gr2
	ldi		@(gr28,#REG__STATUS),gr3
	andicc		gr3,#REG__STATUS_STEP,gr0,icc0
	bne		icc0,#0,__entry_return_singlestep
	movgs		gr2,ccr

	ldi		@(gr28,#REG_SP)    ,sp
	lddi		@(gr28,#REG_GR(2)) ,gr2
	ldi		@(gr28,#REG_GR(28)),gr28

	LEDS		0x67fe
//	movsg		pcsr,gr31
//	LEDS32

#if 0
	# store the current frame in the workram on the FR451
	movgs		gr28,scr2
	sethi.p		%hi(0xfe800000),gr28
	setlo		%lo(0xfe800000),gr28

	stdi		gr2,@(gr28,#REG_GR(2))
	stdi		gr4,@(gr28,#REG_GR(4))
	stdi		gr6,@(gr28,#REG_GR(6))
	stdi		gr8,@(gr28,#REG_GR(8))
	stdi		gr10,@(gr28,#REG_GR(10))
	stdi		gr12,@(gr28,#REG_GR(12))
	stdi		gr14,@(gr28,#REG_GR(14))
	stdi		gr16,@(gr28,#REG_GR(16))
	stdi		gr18,@(gr28,#REG_GR(18))
	stdi		gr24,@(gr28,#REG_GR(24))
	stdi		gr26,@(gr28,#REG_GR(26))
	sti		gr29,@(gr28,#REG_GR(29))
	stdi		gr30,@(gr28,#REG_GR(30))

	movsg		tbr ,gr30
	sti		gr30,@(gr28,#REG_TBR)
	movsg		pcsr,gr30
	sti		gr30,@(gr28,#REG_PC)
	movsg		psr ,gr30
	sti		gr30,@(gr28,#REG_PSR)
	movsg		isr ,gr30
	sti		gr30,@(gr28,#REG_ISR)
	movsg		ccr ,gr30
	movsg		cccr,gr31