mirror of https://gitee.com/openkylin/linux.git
95 lines
1.7 KiB
ArmAsm
95 lines
1.7 KiB
ArmAsm
/* copy_in_user.S: Copy from userspace to userspace.
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*
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* Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com)
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*/
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#include <linux/linkage.h>
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#include <asm/asi.h>
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#include <asm/export.h>
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#define XCC xcc
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#define EX(x,y) \
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98: x,y; \
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.section __ex_table,"a";\
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.align 4; \
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.word 98b, __retl_one; \
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.text; \
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.align 4;
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.register %g2,#scratch
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.register %g3,#scratch
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.text
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.align 32
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/* Don't try to get too fancy here, just nice and
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* simple. This is predominantly used for well aligned
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* small copies in the compat layer. It is also used
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* to copy register windows around during thread cloning.
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*/
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ENTRY(___copy_in_user) /* %o0=dst, %o1=src, %o2=len */
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cmp %o2, 0
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be,pn %XCC, 85f
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or %o0, %o1, %o3
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cmp %o2, 16
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bleu,a,pn %XCC, 80f
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or %o3, %o2, %o3
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/* 16 < len <= 64 */
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andcc %o3, 0x7, %g0
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bne,pn %XCC, 90f
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nop
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andn %o2, 0x7, %o4
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and %o2, 0x7, %o2
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1: subcc %o4, 0x8, %o4
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EX(ldxa [%o1] %asi, %o5)
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EX(stxa %o5, [%o0] %asi)
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add %o1, 0x8, %o1
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bgu,pt %XCC, 1b
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add %o0, 0x8, %o0
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andcc %o2, 0x4, %g0
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be,pt %XCC, 1f
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nop
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sub %o2, 0x4, %o2
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EX(lduwa [%o1] %asi, %o5)
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EX(stwa %o5, [%o0] %asi)
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add %o1, 0x4, %o1
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add %o0, 0x4, %o0
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1: cmp %o2, 0
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be,pt %XCC, 85f
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nop
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ba,pt %xcc, 90f
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nop
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80: /* 0 < len <= 16 */
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andcc %o3, 0x3, %g0
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bne,pn %XCC, 90f
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nop
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82:
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subcc %o2, 4, %o2
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EX(lduwa [%o1] %asi, %g1)
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EX(stwa %g1, [%o0] %asi)
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add %o1, 4, %o1
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bgu,pt %XCC, 82b
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add %o0, 4, %o0
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85: retl
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clr %o0
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.align 32
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90:
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subcc %o2, 1, %o2
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EX(lduba [%o1] %asi, %g1)
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EX(stba %g1, [%o0] %asi)
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add %o1, 1, %o1
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bgu,pt %XCC, 90b
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add %o0, 1, %o0
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retl
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clr %o0
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ENDPROC(___copy_in_user)
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EXPORT_SYMBOL(___copy_in_user)
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