65 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			65 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /*
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|  * This file is subject to the terms and conditions of the GNU General Public
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|  * License.  See the file "COPYING" in the main directory of this archive
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|  * for more details.
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|  *
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|  * Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle
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|  * Copyright (c) 1999 Silicon Graphics, Inc.
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|  */
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| #include <asm/asm.h>
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| #include <asm/asm-offsets.h>
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| #include <asm/export.h>
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| #include <asm/regdef.h>
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| 
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| #define EX(insn,reg,addr,handler)			\
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| 9:	insn	reg, addr;				\
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| 	.section __ex_table,"a";			\
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| 	PTR	9b, handler;				\
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| 	.previous
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| 
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| /*
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|  * Return the size of a string including the ending NUL character up to a
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|  * maximum of a1 or 0 in case of error.
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|  *
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|  * Note: for performance reasons we deliberately accept that a user may
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|  *	 make strlen_user and strnlen_user access the first few KSEG0
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|  *	 bytes.	 There's nothing secret there.	On 64-bit accessing beyond
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|  *	 the maximum is a tad hairier ...
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|  */
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| LEAF(__strnlen_user_asm)
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| 	move		v0, a0
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| 	PTR_ADDU	a1, a0			# stop pointer
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| 1:
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| #ifdef CONFIG_CPU_DADDI_WORKAROUNDS
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| 	.set		noat
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| 	li		AT, 1
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| #endif
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| 	beq		v0, a1, 1f		# limit reached?
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| #ifdef CONFIG_EVA
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| 	.set push
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| 	.set eva
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| 	EX(lbe, t0, (v0), .Lfault)
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| 	.set pop
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| #else
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| 	EX(lb, t0, (v0), .Lfault)
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| #endif
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| 	.set		noreorder
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| 	bnez		t0, 1b
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| 1:
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| #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
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| 	 PTR_ADDIU	v0, 1
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| #else
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| 	 PTR_ADDU	v0, AT
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| 	.set		at
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| #endif
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| 	.set		reorder
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| 	PTR_SUBU	v0, a0
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| 	jr		ra
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| 	END(__strnlen_user_asm)
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| 
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| .Lfault:
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| 	move		v0, zero
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| 	jr		ra
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| 
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| 	EXPORT_SYMBOL(__strnlen_user_asm)
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