CoCalc -- entry.S

GitHub Repository: awilliam/linux-vfio
Path: blob/master/arch/h8300/kernel/entry.S
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/* -*- mode: asm -*-
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 *
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 *  linux/arch/h8300/platform/h8300h/entry.S
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 *
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 *  Yoshinori Sato <[email protected]>
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 *  David McCullough <[email protected]>
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 *
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 */
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/*
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 *  entry.S
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 *  include exception/interrupt gateway
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 *          system call entry
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 */
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#include <linux/sys.h>
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#include <asm/unistd.h>
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#include <asm/setup.h>
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#include <asm/segment.h>
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#include <asm/linkage.h>
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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#include <asm/errno.h>
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#if defined(CONFIG_CPU_H8300H)
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#define USERRET 8
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INTERRUPTS = 64
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	.h8300h
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	.macro	SHLL2 reg
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	shll.l	\reg
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	shll.l	\reg
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	.endm
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	.macro	SHLR2 reg
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	shlr.l	\reg
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	shlr.l	\reg
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	.endm
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	.macro	SAVEREGS
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	mov.l	er0,@-sp
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	mov.l	er1,@-sp
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	mov.l	er2,@-sp
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	mov.l	er3,@-sp
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	.endm
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	.macro	RESTOREREGS
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	mov.l	@sp+,er3
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	mov.l	@sp+,er2
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	.endm
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	.macro	SAVEEXR
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	.endm
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	.macro	RESTOREEXR
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	.endm
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#endif
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#if defined(CONFIG_CPU_H8S)
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#define USERRET 10
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#define USEREXR 8
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INTERRUPTS = 128
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	.h8300s
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	.macro	SHLL2 reg
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	shll.l	#2,\reg
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	.endm
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	.macro	SHLR2 reg
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	shlr.l	#2,\reg
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	.endm
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	.macro	SAVEREGS
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	stm.l	er0-er3,@-sp
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	.endm
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	.macro	RESTOREREGS
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	ldm.l	@sp+,er2-er3
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	.endm
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	.macro	SAVEEXR
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	mov.w	@(USEREXR:16,er0),r1
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	mov.w	r1,@(LEXR-LER3:16,sp)		/* copy EXR */
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	.endm
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	.macro	RESTOREEXR
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	mov.w	@(LEXR-LER1:16,sp),r1		/* restore EXR */
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	mov.b	r1l,r1h
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	mov.w	r1,@(USEREXR:16,er0)
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	.endm
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#endif
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/* CPU context save/restore macros. */
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	.macro	SAVE_ALL
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	mov.l	er0,@-sp
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	stc	ccr,r0l				/* check kernel mode */
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	btst	#4,r0l
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	bne	5f
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	/* user mode */
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	mov.l	sp,@SYMBOL_NAME(sw_usp)
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	mov.l	@sp,er0				/* restore saved er0 */
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	orc	#0x10,ccr			/* switch kernel stack */
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	mov.l	@SYMBOL_NAME(sw_ksp),sp
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	sub.l	#(LRET-LORIG),sp		/* allocate LORIG - LRET */
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	SAVEREGS
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	mov.l   @SYMBOL_NAME(sw_usp),er0
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	mov.l   @(USERRET:16,er0),er1           /* copy the RET addr */
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	mov.l   er1,@(LRET-LER3:16,sp)
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	SAVEEXR
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	mov.l	@(LORIG-LER3:16,sp),er0
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	mov.l	er0,@(LER0-LER3:16,sp)		/* copy ER0 */
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	mov.w	e1,r1				/* e1 highbyte = ccr */
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	and	#0xef,r1h			/* mask mode? flag */
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	bra	6f
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5:
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	/* kernel mode */
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	mov.l	@sp,er0				/* restore saved er0 */
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	subs	#2,sp				/* set dummy ccr */
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	SAVEREGS
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	mov.w	@(LRET-LER3:16,sp),r1		/* copy old ccr */
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6:
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	mov.b	r1h,r1l
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	mov.b	#0,r1h
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	mov.w	r1,@(LCCR-LER3:16,sp)		/* set ccr */
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	mov.l	er6,@-sp			/* syscall arg #6 */
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	mov.l	er5,@-sp			/* syscall arg #5 */
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	mov.l	er4,@-sp			/* syscall arg #4 */
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	.endm					/* r1 = ccr */
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	.macro	RESTORE_ALL
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	mov.l	@sp+,er4
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	mov.l	@sp+,er5
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	mov.l	@sp+,er6
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	RESTOREREGS
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	mov.w	@(LCCR-LER1:16,sp),r0		/* check kernel mode */
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	btst	#4,r0l
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	bne	7f
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	orc	#0x80,ccr
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	mov.l	@SYMBOL_NAME(sw_usp),er0
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	mov.l	@(LER0-LER1:16,sp),er1		/* restore ER0 */
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	mov.l	er1,@er0
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	RESTOREEXR
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	mov.w	@(LCCR-LER1:16,sp),r1		/* restore the RET addr */
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	mov.b	r1l,r1h
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	mov.b	@(LRET+1-LER1:16,sp),r1l
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	mov.w	r1,e1
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	mov.w	@(LRET+2-LER1:16,sp),r1
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	mov.l	er1,@(USERRET:16,er0)
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	mov.l	@sp+,er1
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	add.l	#(LRET-LER1),sp			/* remove LORIG - LRET */
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	mov.l	sp,@SYMBOL_NAME(sw_ksp)
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	andc	#0xef,ccr			/* switch to user mode */
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	mov.l	er0,sp
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	bra	8f
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7:
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	mov.l	@sp+,er1
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	adds	#4,sp
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	adds	#2,sp
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8:
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	mov.l	@sp+,er0
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	adds	#4,sp				/* remove the sw created LVEC */
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	rte
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	.endm
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.globl SYMBOL_NAME(system_call)
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.globl SYMBOL_NAME(ret_from_exception)
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.globl SYMBOL_NAME(ret_from_fork)
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.globl SYMBOL_NAME(ret_from_interrupt)
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.globl SYMBOL_NAME(interrupt_redirect_table)
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.globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
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.globl SYMBOL_NAME(resume)
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.globl SYMBOL_NAME(interrupt_entry)
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.globl SYMBOL_NAME(trace_break)
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#if defined(CONFIG_ROMKERNEL)
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	.section .int_redirect,"ax"
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SYMBOL_NAME_LABEL(interrupt_redirect_table)
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#if defined(CONFIG_CPU_H8300H)
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	.rept	7
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	.long	0
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	.endr
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#endif
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#if defined(CONFIG_CPU_H8S)
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	.rept	5
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	.long	0
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	.endr
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	jmp	@SYMBOL_NAME(trace_break)
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	.long	0
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#endif
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	jsr	@SYMBOL_NAME(interrupt_entry)	/* NMI */
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	jmp	@SYMBOL_NAME(system_call)	/* TRAPA #0 (System call) */
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	.long	0
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	.long	0
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	jmp	@SYMBOL_NAME(trace_break)	/* TRAPA #3 (breakpoint) */
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	.rept	INTERRUPTS-12
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	jsr	@SYMBOL_NAME(interrupt_entry)
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	.endr
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#endif
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#if defined(CONFIG_RAMKERNEL)
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.globl SYMBOL_NAME(interrupt_redirect_table)
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	.section .bss
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SYMBOL_NAME_LABEL(interrupt_redirect_table)
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	.space	4
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#endif
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	.section .text
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	.align	2
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SYMBOL_NAME_LABEL(interrupt_entry)
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	SAVE_ALL
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	mov.l	sp,er0
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	add.l	#LVEC,er0
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	btst	#4,r1l
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	bne	1f
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	/* user LVEC */
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	mov.l	@SYMBOL_NAME(sw_usp),er0
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	adds	#4,er0
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1:
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	mov.l	@er0,er0			/* LVEC address */
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#if defined(CONFIG_ROMKERNEL)
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	sub.l	#SYMBOL_NAME(interrupt_redirect_table),er0
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#endif
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#if defined(CONFIG_RAMKERNEL)
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	mov.l	@SYMBOL_NAME(interrupt_redirect_table),er1
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	sub.l	er1,er0
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#endif
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	SHLR2	er0
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	dec.l	#1,er0
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	mov.l	sp,er1
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	subs	#4,er1				/* adjust ret_pc */
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	jsr	@SYMBOL_NAME(do_IRQ)
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	jmp	@SYMBOL_NAME(ret_from_interrupt)
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SYMBOL_NAME_LABEL(system_call)
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	subs	#4,sp				/* dummy LVEC */
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	SAVE_ALL
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	andc	#0x7f,ccr
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	mov.l	er0,er4
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	/* save top of frame */
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	mov.l	sp,er0
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	jsr	@SYMBOL_NAME(set_esp0)
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	mov.l	sp,er2
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	and.w	#0xe000,r2
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	mov.b	@((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
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	btst	#(TIF_SYSCALL_TRACE & 7),r2l
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	beq	1f
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	jsr	@SYMBOL_NAME(do_syscall_trace)
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1:
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	cmp.l	#NR_syscalls,er4
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	bcc	badsys
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	SHLL2	er4
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	mov.l	#SYMBOL_NAME(sys_call_table),er0
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	add.l	er4,er0
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	mov.l	@er0,er4
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	beq	SYMBOL_NAME(ret_from_exception):16
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	mov.l	@(LER1:16,sp),er0
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	mov.l	@(LER2:16,sp),er1
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	mov.l	@(LER3:16,sp),er2
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	jsr	@er4
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	mov.l	er0,@(LER0:16,sp)		/* save the return value */
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	mov.l	sp,er2
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	and.w	#0xe000,r2
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	mov.b	@((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
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	btst	#(TIF_SYSCALL_TRACE & 7),r2l
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	beq	2f
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	jsr	@SYMBOL_NAME(do_syscall_trace)
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2:
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#if defined(CONFIG_SYSCALL_PRINT)
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	jsr	@SYMBOL_NAME(syscall_print)
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#endif
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	orc	#0x80,ccr
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	bra	resume_userspace
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badsys:
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	mov.l	#-ENOSYS,er0
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	mov.l	er0,@(LER0:16,sp)
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	bra	resume_userspace
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#if !defined(CONFIG_PREEMPT)
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#define resume_kernel restore_all
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#endif
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SYMBOL_NAME_LABEL(ret_from_exception)
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#if defined(CONFIG_PREEMPT)
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	orc	#0x80,ccr
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#endif
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SYMBOL_NAME_LABEL(ret_from_interrupt)
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	mov.b	@(LCCR+1:16,sp),r0l
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	btst	#4,r0l
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	bne	resume_kernel:8		/* return from kernel */
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resume_userspace:
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	andc	#0x7f,ccr
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	mov.l	sp,er4
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	and.w	#0xe000,r4		/* er4 <- current thread info */
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	mov.l	@(TI_FLAGS:16,er4),er1
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	and.l	#_TIF_WORK_MASK,er1
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	beq	restore_all:8
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work_pending:
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	btst	#TIF_NEED_RESCHED,r1l
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	bne	work_resched:8
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	/* work notifysig */
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	mov.l	sp,er0
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	subs	#4,er0			/* er0: pt_regs */
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	jsr	@SYMBOL_NAME(do_notify_resume)
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	bra	restore_all:8
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work_resched:
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	mov.l	sp,er0
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	jsr	@SYMBOL_NAME(set_esp0)
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	jsr	@SYMBOL_NAME(schedule)
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	bra	resume_userspace:8
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restore_all:
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	RESTORE_ALL			/* Does RTE */
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#if defined(CONFIG_PREEMPT)
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resume_kernel:
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	mov.l	@(TI_PRE_COUNT:16,er4),er0
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	bne	restore_all:8
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need_resched:
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	mov.l	@(TI_FLAGS:16,er4),er0
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	btst	#TIF_NEED_RESCHED,r0l
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	beq	restore_all:8
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	mov.b	@(LCCR+1:16,sp),r0l	/* Interrupt Enabled? */
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	bmi	restore_all:8
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	mov.l	#PREEMPT_ACTIVE,er0
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	mov.l	er0,@(TI_PRE_COUNT:16,er4)
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	andc	#0x7f,ccr
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	mov.l	sp,er0
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	jsr	@SYMBOL_NAME(set_esp0)
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	jsr	@SYMBOL_NAME(schedule)
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	orc	#0x80,ccr
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	bra	need_resched:8
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#endif
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SYMBOL_NAME_LABEL(ret_from_fork)
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	mov.l	er2,er0
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	jsr	@SYMBOL_NAME(schedule_tail)
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	jmp	@SYMBOL_NAME(ret_from_exception)
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SYMBOL_NAME_LABEL(resume)
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	/*
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	 * Beware - when entering resume, offset of tss is in d1,
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	 * prev (the current task) is in a0, next (the new task)
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	 * is in a1 and d2.b is non-zero if the mm structure is
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	 * shared between the tasks, so don't change these
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	 * registers until their contents are no longer needed.
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	 */
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	/* save sr */
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	sub.w	r3,r3
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	stc	ccr,r3l
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	mov.w	r3,@(THREAD_CCR+2:16,er0)
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	/* disable interrupts */
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	orc	#0x80,ccr
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	mov.l	@SYMBOL_NAME(sw_usp),er3
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	mov.l	er3,@(THREAD_USP:16,er0)
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	mov.l	sp,@(THREAD_KSP:16,er0)
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	/* Skip address space switching if they are the same. */
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	/* FIXME: what did we hack out of here, this does nothing! */
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	mov.l	@(THREAD_USP:16,er1),er0
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	mov.l	er0,@SYMBOL_NAME(sw_usp)
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	mov.l	@(THREAD_KSP:16,er1),sp
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	/* restore status register */
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	mov.w	@(THREAD_CCR+2:16,er1),r3
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	ldc	r3l,ccr
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	rts
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SYMBOL_NAME_LABEL(trace_break)
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	subs	#4,sp
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	SAVE_ALL
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	sub.l	er1,er1
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	dec.l	#1,er1
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	mov.l	er1,@(LORIG,sp)
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	mov.l	sp,er0
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	jsr	@SYMBOL_NAME(set_esp0)
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	mov.l	@SYMBOL_NAME(sw_usp),er0
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	mov.l	@er0,er1
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	mov.w	@(-2:16,er1),r2
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	cmp.w	#0x5730,r2
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	beq	1f
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	subs	#2,er1
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	mov.l	er1,@er0
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1:
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	and.w	#0xff,e1
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	mov.l	er1,er0
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	jsr	@SYMBOL_NAME(trace_trap)
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	jmp	@SYMBOL_NAME(ret_from_exception)
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	.section	.bss
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SYMBOL_NAME_LABEL(sw_ksp)
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	.space	4
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SYMBOL_NAME_LABEL(sw_usp)
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	.space	4
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	.end
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