xref: /openbmc/linux/arch/sparc/lib/copy_in_user.S (revision 9cfc5c90)
1/* copy_in_user.S: Copy from userspace to userspace.
2 *
3 * Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com)
4 */
5
6#include <linux/linkage.h>
7#include <asm/asi.h>
8
9#define XCC xcc
10
11#define EX(x,y)			\
1298:	x,y;			\
13	.section __ex_table,"a";\
14	.align 4;		\
15	.word 98b, __retl_one;	\
16	.text;			\
17	.align 4;
18
19	.register	%g2,#scratch
20	.register	%g3,#scratch
21
22	.text
23	.align	32
24
25	/* Don't try to get too fancy here, just nice and
26	 * simple.  This is predominantly used for well aligned
27	 * small copies in the compat layer.  It is also used
28	 * to copy register windows around during thread cloning.
29	 */
30
31ENTRY(___copy_in_user)	/* %o0=dst, %o1=src, %o2=len */
32	cmp		%o2, 0
33	be,pn		%XCC, 85f
34	 or		%o0, %o1, %o3
35	cmp		%o2, 16
36	bleu,a,pn	%XCC, 80f
37	 or		%o3, %o2, %o3
38
39	/* 16 < len <= 64 */
40	andcc		%o3, 0x7, %g0
41	bne,pn		%XCC, 90f
42	 nop
43
44	andn		%o2, 0x7, %o4
45	and		%o2, 0x7, %o2
461:	subcc		%o4, 0x8, %o4
47	EX(ldxa [%o1] %asi, %o5)
48	EX(stxa %o5, [%o0] %asi)
49	add		%o1, 0x8, %o1
50	bgu,pt		%XCC, 1b
51	 add		%o0, 0x8, %o0
52	andcc		%o2, 0x4, %g0
53	be,pt		%XCC, 1f
54	 nop
55	sub		%o2, 0x4, %o2
56	EX(lduwa [%o1] %asi, %o5)
57	EX(stwa %o5, [%o0] %asi)
58	add		%o1, 0x4, %o1
59	add		%o0, 0x4, %o0
601:	cmp		%o2, 0
61	be,pt		%XCC, 85f
62	 nop
63	ba,pt		%xcc, 90f
64	 nop
65
6680:	/* 0 < len <= 16 */
67	andcc		%o3, 0x3, %g0
68	bne,pn		%XCC, 90f
69	 nop
70
7182:
72	subcc		%o2, 4, %o2
73	EX(lduwa [%o1] %asi, %g1)
74	EX(stwa %g1, [%o0] %asi)
75	add		%o1, 4, %o1
76	bgu,pt		%XCC, 82b
77	 add		%o0, 4, %o0
78
7985:	retl
80	 clr		%o0
81
82	.align	32
8390:
84	subcc		%o2, 1, %o2
85	EX(lduba [%o1] %asi, %g1)
86	EX(stba %g1, [%o0] %asi)
87	add		%o1, 1, %o1
88	bgu,pt		%XCC, 90b
89	 add		%o0, 1, %o0
90	retl
91	 clr		%o0
92ENDPROC(___copy_in_user)
93