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/* copy_in_user.S: Copy from userspace to userspace.
*
* Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com)
*/
#include <asm/asi.h>
#define XCC xcc
#define EX(x,y) \
98: x,y; \
.section __ex_table,"a";\
.align 4; \
.word 98b, __retl_one; \
.text; \
.align 4;
.register %g2,#scratch
.register %g3,#scratch
.text
.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.
*/
.globl ___copy_in_user
.type ___copy_in_user,#function
___copy_in_user: /* %o0=dst, %o1=src, %o2=len */
/* Writing to %asi is _expensive_ so we hardcode it.
* Reading %asi to check for KERNEL_DS is comparatively
* cheap.
*/
rd %asi, %g1
cmp %g1, ASI_AIUS
bne,pn %icc, memcpy_user_stub
nop
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
sub %o0, %o1, %o3
andn %o2, 0x7, %o4
and %o2, 0x7, %o2
1: subcc %o4, 0x8, %o4
EX(ldxa [%o1] %asi, %o5)
EX(stxa %o5, [%o1 + %o3] ASI_AIUS)
bgu,pt %XCC, 1b
add %o1, 0x8, %o1
andcc %o2, 0x4, %g0
be,pt %XCC, 1f
nop
sub %o2, 0x4, %o2
EX(lduwa [%o1] %asi, %o5)
EX(stwa %o5, [%o1 + %o3] ASI_AIUS)
add %o1, 0x4, %o1
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
sub %o0, %o1, %o3
82:
subcc %o2, 4, %o2
EX(lduwa [%o1] %asi, %g1)
EX(stwa %g1, [%o1 + %o3] ASI_AIUS)
bgu,pt %XCC, 82b
add %o1, 4, %o1
85: retl
clr %o0
.align 32
90:
subcc %o2, 1, %o2
EX(lduba [%o1] %asi, %g1)
EX(stba %g1, [%o1 + %o3] ASI_AIUS)
bgu,pt %XCC, 90b
add %o1, 1, %o1
retl
clr %o0
.size ___copy_in_user, .-___copy_in_user
/* Act like copy_{to,in}_user(), ie. return zero instead
* of original destination pointer. This is invoked when
* copy_{to,in}_user() finds that %asi is kernel space.
*/
.globl memcpy_user_stub
.type memcpy_user_stub,#function
memcpy_user_stub:
save %sp, -192, %sp
mov %i0, %o0
mov %i1, %o1
call memcpy
mov %i2, %o2
ret
restore %g0, %g0, %o0
.size memcpy_user_stub, .-memcpy_user_stub
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