805 lines
		
	
	
	
		
			17 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			805 lines
		
	
	
	
		
			17 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * linux/arch/unicore32/kernel/entry.S
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 *
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 * Code specific to PKUnity SoC and UniCore ISA
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 *
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 * Copyright (C) 2001-2010 GUAN Xue-tao
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 *
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 *  Low-level vector interface routines
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 */
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include <asm/errno.h>
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#include <asm/thread_info.h>
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#include <asm/memory.h>
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#include <asm/unistd.h>
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#include <generated/asm-offsets.h>
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#include "debug-macro.S"
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@
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@ Most of the stack format comes from struct pt_regs, but with
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@ the addition of 8 bytes for storing syscall args 5 and 6.
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@
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#define S_OFF		8
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/*
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 * The SWI code relies on the fact that R0 is at the bottom of the stack
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 * (due to slow/fast restore user regs).
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 */
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#if S_R0 != 0
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#error "Please fix"
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#endif
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	.macro	zero_fp
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#ifdef CONFIG_FRAME_POINTER
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	mov	fp, #0
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#endif
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	.endm
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	.macro	alignment_trap, rtemp
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#ifdef CONFIG_ALIGNMENT_TRAP
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	ldw	\rtemp, .LCcralign
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	ldw	\rtemp, [\rtemp]
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	movc	p0.c1, \rtemp, #0
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#endif
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	.endm
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	.macro	load_user_sp_lr, rd, rtemp, offset = 0
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	mov	\rtemp, asr
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	xor	\rtemp, \rtemp, #(PRIV_MODE ^ SUSR_MODE)
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	mov.a	asr, \rtemp			@ switch to the SUSR mode
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	ldw	sp, [\rd+], #\offset		@ load sp_user
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	ldw	lr, [\rd+], #\offset + 4	@ load lr_user
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	xor	\rtemp, \rtemp, #(PRIV_MODE ^ SUSR_MODE)
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	mov.a	asr, \rtemp			@ switch back to the PRIV mode
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	.endm
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	.macro	priv_exit, rpsr
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	mov.a	bsr, \rpsr
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	ldm.w	(r0 - r15), [sp]+
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	ldm.b	(r16 - pc), [sp]+		@ load r0 - pc, asr
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	.endm
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	.macro	restore_user_regs, fast = 0, offset = 0
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	ldw	r1, [sp+], #\offset + S_PSR	@ get calling asr
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	ldw	lr, [sp+], #\offset + S_PC	@ get pc
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	mov.a	bsr, r1				@ save in bsr_priv
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	.if	\fast
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	add	sp, sp, #\offset + S_R1		@ r0 is syscall return value
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	ldm.w	(r1 - r15), [sp]+		@ get calling r1 - r15
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	ldur	(r16 - lr), [sp]+		@ get calling r16 - lr
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	.else
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	ldm.w	(r0 - r15), [sp]+		@ get calling r0 - r15
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	ldur	(r16 - lr), [sp]+		@ get calling r16 - lr
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	.endif
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	nop
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	add	sp, sp, #S_FRAME_SIZE - S_R16
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	mov.a	pc, lr				@ return
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						@ and move bsr_priv into asr
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	.endm
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	.macro	get_thread_info, rd
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	mov	\rd, sp >> #13
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	mov	\rd, \rd << #13
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	.endm
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	.macro	get_irqnr_and_base, irqnr, irqstat, base, tmp
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	ldw	\base, =(PKUNITY_INTC_BASE)
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	ldw	\irqstat, [\base+], #0xC	@ INTC_ICIP
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	ldw	\tmp,	  [\base+], #0x4	@ INTC_ICMR
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	and.a	\irqstat, \irqstat, \tmp
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	beq	1001f
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	cntlz	\irqnr, \irqstat
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	rsub	\irqnr, \irqnr, #31
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1001:	/* EQ will be set if no irqs pending */
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	.endm
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#ifdef CONFIG_DEBUG_LL
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	.macro	printreg, reg, temp
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		adr	\temp, 901f
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		stm	(r0-r3), [\temp]+
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		stw	lr, [\temp+], #0x10
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		mov	r0, \reg
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		b.l	printhex8
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		mov	r0, #':'
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		b.l	printch
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		mov	r0, pc
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		b.l	printhex8
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		adr	r0, 902f
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		b.l	printascii
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		adr	\temp, 901f
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		ldm	(r0-r3), [\temp]+
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		ldw	lr, [\temp+], #0x10
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		b	903f
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901:	.word	0, 0, 0, 0, 0	@ r0-r3, lr
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902:	.asciz	": epip4d\n"
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	.align
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903:
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	.endm
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#endif
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/*
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 * These are the registers used in the syscall handler, and allow us to
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 * have in theory up to 7 arguments to a function - r0 to r6.
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 *
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 * Note that tbl == why is intentional.
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 *
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 * We must set at least "tsk" and "why" when calling ret_with_reschedule.
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 */
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scno	.req	r21		@ syscall number
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tbl	.req	r22		@ syscall table pointer
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why	.req	r22		@ Linux syscall (!= 0)
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tsk	.req	r23		@ current thread_info
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/*
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 * Interrupt handling.  Preserves r17, r18, r19
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 */
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	.macro	intr_handler
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1:	get_irqnr_and_base r0, r6, r5, lr
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	beq	2f
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	mov	r1, sp
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	@
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	@ routine called with r0 = irq number, r1 = struct pt_regs *
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	@
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	adr	lr, 1b
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	b	asm_do_IRQ
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2:
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	.endm
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/*
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 * PRIV mode handlers
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 */
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	.macro	priv_entry
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	sub	sp, sp, #(S_FRAME_SIZE - 4)
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	stm	(r1 - r15), [sp]+
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	add	r5, sp, #S_R15
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	stm	(r16 - r28), [r5]+
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	ldm	(r1 - r3), [r0]+
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	add	r5, sp, #S_SP - 4	@ here for interlock avoidance
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	mov	r4, #-1			@  ""  ""      ""       ""
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	add	r0, sp, #(S_FRAME_SIZE - 4)
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	stw.w	r1, [sp+], #-4		@ save the "real" r0 copied
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					@ from the exception stack
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	mov	r1, lr
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	@
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	@ We are now ready to fill in the remaining blanks on the stack:
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	@
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	@  r0 - sp_priv
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	@  r1 - lr_priv
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	@  r2 - lr_<exception>, already fixed up for correct return/restart
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	@  r3 - bsr_<exception>
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	@  r4 - orig_r0 (see pt_regs definition in ptrace.h)
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	@
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	stm	(r0 - r4), [r5]+
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	.endm
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/*
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 * User mode handlers
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 *
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 */
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	.macro	user_entry
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	sub	sp, sp, #S_FRAME_SIZE
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	stm	(r1 - r15), [sp+]
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	add	r4, sp, #S_R16
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	stm	(r16 - r28), [r4]+
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	ldm	(r1 - r3), [r0]+
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	add	r0, sp, #S_PC		@ here for interlock avoidance
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	mov	r4, #-1			@  ""  ""     ""        ""
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	stw	r1, [sp]		@ save the "real" r0 copied
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					@ from the exception stack
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	@
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	@ We are now ready to fill in the remaining blanks on the stack:
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	@
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	@  r2 - lr_<exception>, already fixed up for correct return/restart
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	@  r3 - bsr_<exception>
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	@  r4 - orig_r0 (see pt_regs definition in ptrace.h)
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	@
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	@ Also, separately save sp_user and lr_user
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	@
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	stm	(r2 - r4), [r0]+
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	stur	(sp, lr), [r0-]
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	@
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	@ Enable the alignment trap while in kernel mode
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	@
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	alignment_trap r0
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	@
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	@ Clear FP to mark the first stack frame
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	@
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	zero_fp
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	.endm
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	.text
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@
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@ __invalid - generic code for failed exception
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@			(re-entrant version of handlers)
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@
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__invalid:
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	sub	sp, sp, #S_FRAME_SIZE
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	stm	(r1 - r15), [sp+]
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	add	r1, sp, #S_R16
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	stm	(r16 - r28, sp, lr), [r1]+
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	zero_fp
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	ldm	(r4 - r6), [r0]+
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	add	r0, sp, #S_PC		@ here for interlock avoidance
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	mov	r7, #-1			@  ""   ""    ""        ""
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	stw	r4, [sp]		@ save preserved r0
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	stm	(r5 - r7), [r0]+	@ lr_<exception>,
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					@ asr_<exception>, "old_r0"
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	mov	r0, sp
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	mov	r1, asr
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	b	bad_mode
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ENDPROC(__invalid)
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	.align	5
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__dabt_priv:
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	priv_entry
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	@
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	@ get ready to re-enable interrupts if appropriate
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	@
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	mov	r17, asr
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	cand.a	r3, #PSR_I_BIT
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	bne	1f
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	andn	r17, r17, #PSR_I_BIT
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1:
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	@
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	@ Call the processor-specific abort handler:
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	@
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	@  r2 - aborted context pc
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	@  r3 - aborted context asr
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	@
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	@ The abort handler must return the aborted address in r0, and
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	@ the fault status register in r1.
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	@
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	movc	r1, p0.c3, #0		@ get FSR
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	movc	r0, p0.c4, #0		@ get FAR
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	@
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	@ set desired INTR state, then call main handler
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	@
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	mov.a	asr, r17
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	mov	r2, sp
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	b.l	do_DataAbort
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	@
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	@ INTRs off again before pulling preserved data off the stack
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	@
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	disable_irq r0
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	@
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	@ restore BSR and restart the instruction
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	@
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	ldw	r2, [sp+], #S_PSR
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	priv_exit r2				@ return from exception
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ENDPROC(__dabt_priv)
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	.align	5
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__intr_priv:
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	priv_entry
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	intr_handler
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	mov	r0, #0				@ epip4d
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	movc	p0.c5, r0, #14
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	nop; nop; nop; nop; nop; nop; nop; nop
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	ldw	r4, [sp+], #S_PSR		@ irqs are already disabled
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	priv_exit r4				@ return from exception
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ENDPROC(__intr_priv)
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	.ltorg
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	.align	5
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__extn_priv:
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	priv_entry
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	mov	r0, sp				@ struct pt_regs *regs
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	mov	r1, asr
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	b	bad_mode			@ not supported
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ENDPROC(__extn_priv)
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	.align	5
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__pabt_priv:
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	priv_entry
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	@
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	@ re-enable interrupts if appropriate
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	@
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	mov	r17, asr
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	cand.a	r3, #PSR_I_BIT
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	bne	1f
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	andn	r17, r17, #PSR_I_BIT
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1:
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	@
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	@ set args, then call main handler
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	@
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	@  r0 - address of faulting instruction
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	@  r1 - pointer to registers on stack
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	@
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	mov	r0, r2			@ pass address of aborted instruction
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	mov	r1, #5
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	mov.a	asr, r17
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	mov	r2, sp			@ regs
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	b.l	do_PrefetchAbort	@ call abort handler
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	@
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	@ INTRs off again before pulling preserved data off the stack
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	@
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	disable_irq r0
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	@
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	@ restore BSR and restart the instruction
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	@
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	ldw	r2, [sp+], #S_PSR
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	priv_exit r2			@ return from exception
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ENDPROC(__pabt_priv)
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	.align	5
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.LCcralign:
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	.word	cr_alignment
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	.align	5
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__dabt_user:
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	user_entry
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#ifdef CONFIG_UNICORE_FPU_F64
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	cff	ip, s31
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	cand.a	ip, #0x08000000		@ FPU execption traps?
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	beq	209f
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	ldw	ip, [sp+], #S_PC
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	add	ip, ip, #4
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	stw	ip, [sp+], #S_PC
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	@
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	@ fall through to the emulation code, which returns using r19 if
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	@ it has emulated the instruction, or the more conventional lr
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	@ if we are to treat this as a real extended instruction
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	@
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	@  r0 - instruction
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	@
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1:	ldw.u	r0, [r2]
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	adr	r19, ret_from_exception
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	adr	lr, 209f
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	@
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	@ fallthrough to call do_uc_f64
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	@
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/*
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 * Check whether the instruction is a co-processor instruction.
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 * If yes, we need to call the relevant co-processor handler.
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 *
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 * Note that we don't do a full check here for the co-processor
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 * instructions; all instructions with bit 27 set are well
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 * defined.  The only instructions that should fault are the
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 * co-processor instructions.
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 *
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 * Emulators may wish to make use of the following registers:
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 *  r0  = instruction opcode.
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 *  r2  = PC
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 *  r19 = normal "successful" return address
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 *  r20 = this threads thread_info structure.
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 *  lr  = unrecognised instruction return address
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 */
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	get_thread_info r20			@ get current thread
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	and	r8, r0, #0x00003c00		@ mask out CP number
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	mov	r7, #1
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	stb	r7, [r20+], #TI_USED_CP + 2	@ set appropriate used_cp[]
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	@ F64 hardware support entry point.
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	@  r0  = faulted instruction
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	@  r19 = return address
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	@  r20 = fp_state
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	enable_irq r4
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	add	r20, r20, #TI_FPSTATE	@ r20 = workspace
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	cff	r1, s31			@ get fpu FPSCR
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	andn    r2, r1, #0x08000000
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	ctf     r2, s31			@ clear 27 bit
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	mov	r2, sp			@ nothing stacked - regdump is at TOS
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	mov	lr, r19			@ setup for a return to the user code
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	@ Now call the C code to package up the bounce to the support code
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	@   r0 holds the trigger instruction
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	@   r1 holds the FPSCR value
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	@   r2 pointer to register dump
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	b	ucf64_exchandler
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209:
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#endif
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	@
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	@ Call the processor-specific abort handler:
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	@
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	@  r2 - aborted context pc
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	@  r3 - aborted context asr
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	@
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	@ The abort handler must return the aborted address in r0, and
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	@ the fault status register in r1.
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	@
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	movc	r1, p0.c3, #0		@ get FSR
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						|
	movc	r0, p0.c4, #0		@ get FAR
 | 
						|
 | 
						|
	@
 | 
						|
	@ INTRs on, then call the main handler
 | 
						|
	@
 | 
						|
	enable_irq r2
 | 
						|
	mov	r2, sp
 | 
						|
	adr	lr, ret_from_exception
 | 
						|
	b	do_DataAbort
 | 
						|
ENDPROC(__dabt_user)
 | 
						|
 | 
						|
	.align	5
 | 
						|
__intr_user:
 | 
						|
	user_entry
 | 
						|
 | 
						|
	get_thread_info tsk
 | 
						|
 | 
						|
	intr_handler
 | 
						|
 | 
						|
	mov	why, #0
 | 
						|
	b	ret_to_user
 | 
						|
ENDPROC(__intr_user)
 | 
						|
 | 
						|
	.ltorg
 | 
						|
 | 
						|
	.align	5
 | 
						|
__extn_user:
 | 
						|
	user_entry
 | 
						|
 | 
						|
	mov	r0, sp
 | 
						|
	mov	r1, asr
 | 
						|
	b	bad_mode
 | 
						|
ENDPROC(__extn_user)
 | 
						|
 | 
						|
	.align	5
 | 
						|
__pabt_user:
 | 
						|
	user_entry
 | 
						|
 | 
						|
	mov	r0, r2			@ pass address of aborted instruction.
 | 
						|
	mov	r1, #5
 | 
						|
	enable_irq r1			@ Enable interrupts
 | 
						|
	mov	r2, sp			@ regs
 | 
						|
	b.l	do_PrefetchAbort	@ call abort handler
 | 
						|
	/* fall through */
 | 
						|
/*
 | 
						|
 * This is the return code to user mode for abort handlers
 | 
						|
 */
 | 
						|
ENTRY(ret_from_exception)
 | 
						|
	get_thread_info tsk
 | 
						|
	mov	why, #0
 | 
						|
	b	ret_to_user
 | 
						|
ENDPROC(__pabt_user)
 | 
						|
ENDPROC(ret_from_exception)
 | 
						|
 | 
						|
/*
 | 
						|
 * Register switch for UniCore V2 processors
 | 
						|
 * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
 | 
						|
 * previous and next are guaranteed not to be the same.
 | 
						|
 */
 | 
						|
ENTRY(__switch_to)
 | 
						|
	add	ip, r1, #TI_CPU_SAVE
 | 
						|
	stm.w	(r4 - r15), [ip]+
 | 
						|
	stm.w	(r16 - r27, sp, lr), [ip]+
 | 
						|
 | 
						|
#ifdef	CONFIG_UNICORE_FPU_F64
 | 
						|
	add	ip, r1, #TI_FPSTATE
 | 
						|
	sfm.w	(f0  - f7 ), [ip]+
 | 
						|
	sfm.w	(f8  - f15), [ip]+
 | 
						|
	sfm.w	(f16 - f23), [ip]+
 | 
						|
	sfm.w	(f24 - f31), [ip]+
 | 
						|
	cff	r4, s31
 | 
						|
	stw	r4, [ip]
 | 
						|
 | 
						|
	add	ip, r2, #TI_FPSTATE
 | 
						|
	lfm.w	(f0  - f7 ), [ip]+
 | 
						|
	lfm.w	(f8  - f15), [ip]+
 | 
						|
	lfm.w	(f16 - f23), [ip]+
 | 
						|
	lfm.w	(f24 - f31), [ip]+
 | 
						|
	ldw	r4, [ip]
 | 
						|
	ctf	r4, s31
 | 
						|
#endif
 | 
						|
	add	ip, r2, #TI_CPU_SAVE
 | 
						|
	ldm.w	(r4 - r15), [ip]+
 | 
						|
	ldm	(r16 - r27, sp, pc), [ip]+	@ Load all regs saved previously
 | 
						|
ENDPROC(__switch_to)
 | 
						|
 | 
						|
	.align	5
 | 
						|
/*
 | 
						|
 * This is the fast syscall return path.  We do as little as
 | 
						|
 * possible here, and this includes saving r0 back into the PRIV
 | 
						|
 * stack.
 | 
						|
 */
 | 
						|
ret_fast_syscall:
 | 
						|
	disable_irq r1				@ disable interrupts
 | 
						|
	ldw	r1, [tsk+], #TI_FLAGS
 | 
						|
	cand.a	r1, #_TIF_WORK_MASK
 | 
						|
	bne	fast_work_pending
 | 
						|
 | 
						|
	@ fast_restore_user_regs
 | 
						|
	restore_user_regs fast = 1, offset = S_OFF
 | 
						|
 | 
						|
/*
 | 
						|
 * Ok, we need to do extra processing, enter the slow path.
 | 
						|
 */
 | 
						|
fast_work_pending:
 | 
						|
	stw.w	r0, [sp+], #S_R0+S_OFF		@ returned r0
 | 
						|
work_pending:
 | 
						|
	cand.a	r1, #_TIF_NEED_RESCHED
 | 
						|
	bne	work_resched
 | 
						|
	mov	r0, sp				@ 'regs'
 | 
						|
	mov	r2, why				@ 'syscall'
 | 
						|
	cand.a	r1, #_TIF_SIGPENDING		@ delivering a signal?
 | 
						|
	cmovne	why, #0				@ prevent further restarts
 | 
						|
	b.l	do_notify_resume
 | 
						|
	b	ret_slow_syscall		@ Check work again
 | 
						|
 | 
						|
work_resched:
 | 
						|
	b.l	schedule
 | 
						|
/*
 | 
						|
 * "slow" syscall return path.  "why" tells us if this was a real syscall.
 | 
						|
 */
 | 
						|
ENTRY(ret_to_user)
 | 
						|
ret_slow_syscall:
 | 
						|
	disable_irq r1				@ disable interrupts
 | 
						|
	get_thread_info tsk			@ epip4d, one path error?!
 | 
						|
	ldw	r1, [tsk+], #TI_FLAGS
 | 
						|
	cand.a	r1, #_TIF_WORK_MASK
 | 
						|
	bne	work_pending
 | 
						|
no_work_pending:
 | 
						|
	@ slow_restore_user_regs
 | 
						|
	restore_user_regs fast = 0, offset = 0
 | 
						|
ENDPROC(ret_to_user)
 | 
						|
 | 
						|
/*
 | 
						|
 * This is how we return from a fork.
 | 
						|
 */
 | 
						|
ENTRY(ret_from_fork)
 | 
						|
	b.l	schedule_tail
 | 
						|
	b	ret_slow_syscall
 | 
						|
ENDPROC(ret_from_fork)
 | 
						|
 | 
						|
ENTRY(ret_from_kernel_thread)
 | 
						|
	b.l	schedule_tail
 | 
						|
	mov	r0, r5
 | 
						|
	adr	lr, ret_slow_syscall
 | 
						|
	mov	pc, r4
 | 
						|
ENDPROC(ret_from_kernel_thread)
 | 
						|
 | 
						|
/*=============================================================================
 | 
						|
 * SWI handler
 | 
						|
 *-----------------------------------------------------------------------------
 | 
						|
 */
 | 
						|
	.align	5
 | 
						|
ENTRY(vector_swi)
 | 
						|
	sub	sp, sp, #S_FRAME_SIZE
 | 
						|
	stm	(r0 - r15), [sp]+		@ Calling r0 - r15
 | 
						|
	add	r8, sp, #S_R16
 | 
						|
	stm	(r16 - r28), [r8]+		@ Calling r16 - r28
 | 
						|
	add	r8, sp, #S_PC
 | 
						|
	stur	(sp, lr), [r8-]			@ Calling sp, lr
 | 
						|
	mov	r8, bsr				@ called from non-REAL mode
 | 
						|
	stw	lr, [sp+], #S_PC		@ Save calling PC
 | 
						|
	stw	r8, [sp+], #S_PSR		@ Save ASR
 | 
						|
	stw	r0, [sp+], #S_OLD_R0		@ Save OLD_R0
 | 
						|
	zero_fp
 | 
						|
 | 
						|
	/*
 | 
						|
	 * Get the system call number.
 | 
						|
	 */
 | 
						|
	sub	ip, lr, #4
 | 
						|
	ldw.u	scno, [ip]			@ get SWI instruction
 | 
						|
 | 
						|
#ifdef CONFIG_ALIGNMENT_TRAP
 | 
						|
	ldw	ip, __cr_alignment
 | 
						|
	ldw	ip, [ip]
 | 
						|
	movc	p0.c1, ip, #0                   @ update control register
 | 
						|
#endif
 | 
						|
	enable_irq ip
 | 
						|
 | 
						|
	get_thread_info tsk
 | 
						|
	ldw	tbl, =sys_call_table		@ load syscall table pointer
 | 
						|
 | 
						|
	andn	scno, scno, #0xff000000		@ mask off SWI op-code
 | 
						|
	andn	scno, scno, #0x00ff0000		@ mask off SWI op-code
 | 
						|
 | 
						|
	stm.w	(r4, r5), [sp-]			@ push fifth and sixth args
 | 
						|
	ldw	ip, [tsk+], #TI_FLAGS		@ check for syscall tracing
 | 
						|
	cand.a	ip, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
 | 
						|
	bne	__sys_trace
 | 
						|
 | 
						|
	csub.a	scno, #__NR_syscalls		@ check upper syscall limit
 | 
						|
	adr	lr, ret_fast_syscall		@ return address
 | 
						|
	bea	1f
 | 
						|
	ldw	pc, [tbl+], scno << #2		@ call sys_* routine
 | 
						|
1:
 | 
						|
	add	r1, sp, #S_OFF
 | 
						|
2:	mov	why, #0				@ no longer a real syscall
 | 
						|
	b	sys_ni_syscall			@ not private func
 | 
						|
 | 
						|
	/*
 | 
						|
	 * This is the really slow path.  We're going to be doing
 | 
						|
	 * context switches, and waiting for our parent to respond.
 | 
						|
	 */
 | 
						|
__sys_trace:
 | 
						|
	mov	r2, scno
 | 
						|
	add	r1, sp, #S_OFF
 | 
						|
	mov	r0, #0				@ trace entry [IP = 0]
 | 
						|
	b.l	syscall_trace
 | 
						|
 | 
						|
	adr	lr, __sys_trace_return		@ return address
 | 
						|
	mov	scno, r0			@ syscall number (possibly new)
 | 
						|
	add	r1, sp, #S_R0 + S_OFF		@ pointer to regs
 | 
						|
	csub.a	scno, #__NR_syscalls		@ check upper syscall limit
 | 
						|
	bea	2b
 | 
						|
	ldm	(r0 - r3), [r1]+		@ have to reload r0 - r3
 | 
						|
	ldw	pc, [tbl+], scno << #2		@ call sys_* routine
 | 
						|
 | 
						|
__sys_trace_return:
 | 
						|
	stw.w	r0, [sp+], #S_R0 + S_OFF	@ save returned r0
 | 
						|
	mov	r2, scno
 | 
						|
	mov	r1, sp
 | 
						|
	mov	r0, #1				@ trace exit [IP = 1]
 | 
						|
	b.l	syscall_trace
 | 
						|
	b	ret_slow_syscall
 | 
						|
 | 
						|
	.align	5
 | 
						|
#ifdef CONFIG_ALIGNMENT_TRAP
 | 
						|
	.type	__cr_alignment, #object
 | 
						|
__cr_alignment:
 | 
						|
	.word	cr_alignment
 | 
						|
#endif
 | 
						|
	.ltorg
 | 
						|
 | 
						|
ENTRY(sys_rt_sigreturn)
 | 
						|
		add	r0, sp, #S_OFF
 | 
						|
		mov	why, #0		@ prevent syscall restart handling
 | 
						|
		b	__sys_rt_sigreturn
 | 
						|
ENDPROC(sys_rt_sigreturn)
 | 
						|
 | 
						|
	__INIT
 | 
						|
 | 
						|
/*
 | 
						|
 * Vector stubs.
 | 
						|
 *
 | 
						|
 * This code is copied to 0xffff0200 so we can use branches in the
 | 
						|
 * vectors, rather than ldr's.  Note that this code must not
 | 
						|
 * exceed 0x300 bytes.
 | 
						|
 *
 | 
						|
 * Common stub entry macro:
 | 
						|
 *   Enter in INTR mode, bsr = PRIV/USER ASR, lr = PRIV/USER PC
 | 
						|
 *
 | 
						|
 * SP points to a minimal amount of processor-private memory, the address
 | 
						|
 * of which is copied into r0 for the mode specific abort handler.
 | 
						|
 */
 | 
						|
	.macro	vector_stub, name, mode
 | 
						|
	.align	5
 | 
						|
 | 
						|
vector_\name:
 | 
						|
	@
 | 
						|
	@ Save r0, lr_<exception> (parent PC) and bsr_<exception>
 | 
						|
	@ (parent ASR)
 | 
						|
	@
 | 
						|
	stw	r0, [sp]
 | 
						|
	stw	lr, [sp+], #4		@ save r0, lr
 | 
						|
	mov	lr, bsr
 | 
						|
	stw	lr, [sp+], #8		@ save bsr
 | 
						|
 | 
						|
	@
 | 
						|
	@ Prepare for PRIV mode.  INTRs remain disabled.
 | 
						|
	@
 | 
						|
	mov	r0, asr
 | 
						|
	xor	r0, r0, #(\mode ^ PRIV_MODE)
 | 
						|
	mov.a	bsr, r0
 | 
						|
 | 
						|
	@
 | 
						|
	@ the branch table must immediately follow this code
 | 
						|
	@
 | 
						|
	and	lr, lr, #0x03
 | 
						|
	add	lr, lr, #1
 | 
						|
	mov	r0, sp
 | 
						|
	ldw	lr, [pc+], lr << #2
 | 
						|
	mov.a	pc, lr			@ branch to handler in PRIV mode
 | 
						|
ENDPROC(vector_\name)
 | 
						|
	.align	2
 | 
						|
	@ handler addresses follow this label
 | 
						|
	.endm
 | 
						|
 | 
						|
	.globl	__stubs_start
 | 
						|
__stubs_start:
 | 
						|
/*
 | 
						|
 * Interrupt dispatcher
 | 
						|
 */
 | 
						|
	vector_stub	intr, INTR_MODE
 | 
						|
 | 
						|
	.long	__intr_user			@  0  (USER)
 | 
						|
	.long	__invalid			@  1
 | 
						|
	.long	__invalid			@  2
 | 
						|
	.long	__intr_priv			@  3  (PRIV)
 | 
						|
 | 
						|
/*
 | 
						|
 * Data abort dispatcher
 | 
						|
 * Enter in ABT mode, bsr = USER ASR, lr = USER PC
 | 
						|
 */
 | 
						|
	vector_stub	dabt, ABRT_MODE
 | 
						|
 | 
						|
	.long	__dabt_user			@  0  (USER)
 | 
						|
	.long	__invalid			@  1
 | 
						|
	.long	__invalid			@  2  (INTR)
 | 
						|
	.long	__dabt_priv			@  3  (PRIV)
 | 
						|
 | 
						|
/*
 | 
						|
 * Prefetch abort dispatcher
 | 
						|
 * Enter in ABT mode, bsr = USER ASR, lr = USER PC
 | 
						|
 */
 | 
						|
	vector_stub	pabt, ABRT_MODE
 | 
						|
 | 
						|
	.long	__pabt_user			@  0 (USER)
 | 
						|
	.long	__invalid			@  1
 | 
						|
	.long	__invalid			@  2 (INTR)
 | 
						|
	.long	__pabt_priv			@  3 (PRIV)
 | 
						|
 | 
						|
/*
 | 
						|
 * Undef instr entry dispatcher
 | 
						|
 * Enter in EXTN mode, bsr = PRIV/USER ASR, lr = PRIV/USER PC
 | 
						|
 */
 | 
						|
	vector_stub	extn, EXTN_MODE
 | 
						|
 | 
						|
	.long	__extn_user			@  0 (USER)
 | 
						|
	.long	__invalid			@  1
 | 
						|
	.long	__invalid			@  2 (INTR)
 | 
						|
	.long	__extn_priv			@  3 (PRIV)
 | 
						|
 | 
						|
/*
 | 
						|
 * We group all the following data together to optimise
 | 
						|
 * for CPUs with separate I & D caches.
 | 
						|
 */
 | 
						|
	.align	5
 | 
						|
 | 
						|
.LCvswi:
 | 
						|
	.word	vector_swi
 | 
						|
 | 
						|
	.globl	__stubs_end
 | 
						|
__stubs_end:
 | 
						|
 | 
						|
	.equ	stubs_offset, __vectors_start + 0x200 - __stubs_start
 | 
						|
 | 
						|
	.globl	__vectors_start
 | 
						|
__vectors_start:
 | 
						|
	jepriv	SYS_ERROR0
 | 
						|
	b	vector_extn + stubs_offset
 | 
						|
	ldw	pc, .LCvswi + stubs_offset
 | 
						|
	b	vector_pabt + stubs_offset
 | 
						|
	b	vector_dabt + stubs_offset
 | 
						|
	jepriv	SYS_ERROR0
 | 
						|
	b	vector_intr + stubs_offset
 | 
						|
	jepriv	SYS_ERROR0
 | 
						|
 | 
						|
	.globl	__vectors_end
 | 
						|
__vectors_end:
 | 
						|
 | 
						|
	.data
 | 
						|
 | 
						|
	.globl	cr_alignment
 | 
						|
	.globl	cr_no_alignment
 | 
						|
cr_alignment:
 | 
						|
	.space	4
 | 
						|
cr_no_alignment:
 | 
						|
	.space	4
 |