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copy_in_user.S
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/* SPDX-License-Identifier: GPL-2.0 */
/* copy_in_user.S: Copy from userspace to userspace.
*
* Copyright (C) 1999, 2000, 2004 David S. Miller ([email protected])
*/
#include <linux/linkage.h>
#include <asm/asi.h>
#include <asm/export.h>
#define XCC xcc
#define EX(x,y,z) \
98: x,y; \
.section __ex_table,"a";\
.align 4; \
.word 98b, z; \
.text; \
.align 4;
#define EX_O4(x,y) EX(x,y,__retl_o4_plus_8)
#define EX_O2_4(x,y) EX(x,y,__retl_o2_plus_4)
#define EX_O2_1(x,y) EX(x,y,__retl_o2_plus_1)
.register %g2,#scratch
.register %g3,#scratch
.text
__retl_o4_plus_8:
add %o4, %o2, %o4
retl
add %o4, 8, %o0
__retl_o2_plus_4:
retl
add %o2, 4, %o0
__retl_o2_plus_1:
retl
add %o2, 1, %o0
.align 32
/* Don't try to get too fancy here, just nice and
* simple. This is predominantly used for well aligned
* small copies in the compat layer. It is also used
* to copy register windows around during thread cloning.
*/
ENTRY(raw_copy_in_user) /* %o0=dst, %o1=src, %o2=len */
cmp %o2, 0
be,pn %XCC, 85f
or %o0, %o1, %o3
cmp %o2, 16
bleu,a,pn %XCC, 80f
or %o3, %o2, %o3
/* 16 < len <= 64 */
andcc %o3, 0x7, %g0
bne,pn %XCC, 90f
nop
andn %o2, 0x7, %o4
and %o2, 0x7, %o2
1: subcc %o4, 0x8, %o4
EX_O4(ldxa [%o1] %asi, %o5)
EX_O4(stxa %o5, [%o0] %asi)
add %o1, 0x8, %o1
bgu,pt %XCC, 1b
add %o0, 0x8, %o0
andcc %o2, 0x4, %g0
be,pt %XCC, 1f
nop
sub %o2, 0x4, %o2
EX_O2_4(lduwa [%o1] %asi, %o5)
EX_O2_4(stwa %o5, [%o0] %asi)
add %o1, 0x4, %o1
add %o0, 0x4, %o0
1: cmp %o2, 0
be,pt %XCC, 85f
nop
ba,pt %xcc, 90f
nop
80: /* 0 < len <= 16 */
andcc %o3, 0x3, %g0
bne,pn %XCC, 90f
nop
82:
subcc %o2, 4, %o2
EX_O2_4(lduwa [%o1] %asi, %g1)
EX_O2_4(stwa %g1, [%o0] %asi)
add %o1, 4, %o1
bgu,pt %XCC, 82b
add %o0, 4, %o0
85: retl
clr %o0
.align 32
90:
subcc %o2, 1, %o2
EX_O2_1(lduba [%o1] %asi, %g1)
EX_O2_1(stba %g1, [%o0] %asi)
add %o1, 1, %o1
bgu,pt %XCC, 90b
add %o0, 1, %o0
retl
clr %o0
ENDPROC(raw_copy_in_user)
EXPORT_SYMBOL(raw_copy_in_user)