Eric Lee / smarc-fsl-linux-kernel

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arch/sh/lib/__clear_user.S 1.75 KB
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510c72ad2   Paul Mundt   sh: Fixup various... 
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  /*
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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   * __clear_user_page, __clear_user, clear_page implementation of SuperH
   *
   * Copyright (C) 2001  Kaz Kojima
   * Copyright (C) 2001, 2002  Niibe Yutaka
510c72ad2   Paul Mundt   sh: Fixup various... 
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   * Copyright (C) 2006  Paul Mundt
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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   */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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  #include <linux/linkage.h>
510c72ad2   Paul Mundt   sh: Fixup various... 
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  #include <asm/page.h>
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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1da177e4c
 
 Linus Torvalds
 
Linux-2.6.12-rc2




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  ENTRY(__clear_user)
  	!
  	mov	#0, r0









fea966f75
 
 Stuart Menefy
 
sh: Remove implic...




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  	mov	#0xffffffe0, r1









1da177e4c
 
 Linus Torvalds
 
Linux-2.6.12-rc2




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  	!
  	! r4..(r4+31)&~32 	   -------- not aligned	[ Area 0 ]
  	! (r4+31)&~32..(r4+r5)&~32 -------- aligned	[ Area 1 ]
  	! (r4+r5)&~32..r4+r5       -------- not aligned	[ Area 2 ]
  	!
  	! Clear area 0
  	mov	r4, r2
  	!
  	tst	r1, r5		! length < 32
  	bt	.Larea2		! skip to remainder
  	!
  	add	#31, r2
  	and	r1, r2
  	cmp/eq	r4, r2
  	bt	.Larea1
  	mov	r2, r3
  	sub	r4, r3
  	mov	r3, r7
  	mov	r4, r2
  	!
  .L0:	dt	r3
  0:	mov.b	r0, @r2
  	bf/s	.L0
  	 add	#1, r2
  	!
  	sub	r7, r5
  	mov	r2, r4
  .Larea1:
  	mov	r4, r3
  	add	r5, r3
  	and	r1, r3
  	cmp/hi	r2, r3
  	bf	.Larea2
  	!
  	! Clear area 1
  #if defined(CONFIG_CPU_SH4)
  1:	movca.l	r0, @r2
  #else
  1:	mov.l	r0, @r2
  #endif
  	add	#4, r2
  2:	mov.l	r0, @r2
  	add	#4, r2
  3:	mov.l	r0, @r2
  	add	#4, r2
  4:	mov.l	r0, @r2
  	add	#4, r2
  5:	mov.l	r0, @r2
  	add	#4, r2
  6:	mov.l	r0, @r2
  	add	#4, r2
  7:	mov.l	r0, @r2
  	add	#4, r2
  8:	mov.l	r0, @r2
  	add	#4, r2
  	cmp/hi	r2, r3
  	bt/s	1b
  	 nop
  	!
  	! Clear area 2
  .Larea2:
  	mov	r4, r3
  	add	r5, r3
  	cmp/hs	r3, r2
  	bt/s	.Ldone
  	 sub	r2, r3
  .L2:	dt	r3
  9:	mov.b	r0, @r2
  	bf/s	.L2
  	 add	#1, r2
  	!
  .Ldone:	rts
  	 mov	#0, r0	! return 0 as normal return
  
  	! return the number of bytes remained
  .Lbad_clear_user:
  	mov	r4, r0
  	add	r5, r0
  	rts
  	 sub	r2, r0
  
  .section __ex_table,"a"
  	.align 2
  	.long	0b, .Lbad_clear_user
  	.long	1b, .Lbad_clear_user
  	.long	2b, .Lbad_clear_user
  	.long	3b, .Lbad_clear_user
  	.long	4b, .Lbad_clear_user
  	.long	5b, .Lbad_clear_user
  	.long	6b, .Lbad_clear_user
  	.long	7b, .Lbad_clear_user
  	.long	8b, .Lbad_clear_user
  	.long	9b, .Lbad_clear_user
  .previous