xref: /OK3568_Linux_fs/kernel/arch/csky/abiv2/memset.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun#include <linux/linkage.h>
5*4882a593Smuzhiyun#include "sysdep.h"
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun	.weak memset
8*4882a593SmuzhiyunENTRY(__memset)
9*4882a593SmuzhiyunENTRY(memset)
10*4882a593Smuzhiyun	/* Test if len less than 4 bytes.  */
11*4882a593Smuzhiyun	mov	r12, r0
12*4882a593Smuzhiyun	cmplti	r2, 8
13*4882a593Smuzhiyun	bt	.L_set_by_byte
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun	andi	r13, r0, 3
16*4882a593Smuzhiyun	movi	r19, 4
17*4882a593Smuzhiyun	/* Test if dest is not 4 bytes aligned.  */
18*4882a593Smuzhiyun	bnez	r13, .L_dest_not_aligned
19*4882a593Smuzhiyun	/* Hardware can handle unaligned access directly.  */
20*4882a593Smuzhiyun.L_dest_aligned:
21*4882a593Smuzhiyun        zextb   r3, r1
22*4882a593Smuzhiyun        lsli    r1, 8
23*4882a593Smuzhiyun        or      r1, r3
24*4882a593Smuzhiyun        lsli    r3, r1, 16
25*4882a593Smuzhiyun        or      r3, r1
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun	/* If dest is aligned, then copy.  */
28*4882a593Smuzhiyun	zext	r18, r2, 31, 4
29*4882a593Smuzhiyun	/* Test if len less than 16 bytes.  */
30*4882a593Smuzhiyun	bez	r18, .L_len_less_16bytes
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun	LABLE_ALIGN
33*4882a593Smuzhiyun.L_len_larger_16bytes:
34*4882a593Smuzhiyun	stw	r3, (r0, 0)
35*4882a593Smuzhiyun	stw	r3, (r0, 4)
36*4882a593Smuzhiyun	stw	r3, (r0, 8)
37*4882a593Smuzhiyun	stw	r3, (r0, 12)
38*4882a593Smuzhiyun	PRE_BNEZAD (r18)
39*4882a593Smuzhiyun	addi	r0, 16
40*4882a593Smuzhiyun	BNEZAD (r18, .L_len_larger_16bytes)
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun.L_len_less_16bytes:
43*4882a593Smuzhiyun	zext	r18, r2, 3, 2
44*4882a593Smuzhiyun	andi	r2, 3
45*4882a593Smuzhiyun	bez	r18, .L_set_by_byte
46*4882a593Smuzhiyun.L_len_less_16bytes_loop:
47*4882a593Smuzhiyun	stw	r3, (r0, 0)
48*4882a593Smuzhiyun	PRE_BNEZAD (r18)
49*4882a593Smuzhiyun	addi	r0, 4
50*4882a593Smuzhiyun	BNEZAD (r18, .L_len_less_16bytes_loop)
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun	/* Test if len less than 4 bytes.  */
53*4882a593Smuzhiyun.L_set_by_byte:
54*4882a593Smuzhiyun	zext	r18, r2, 2, 0
55*4882a593Smuzhiyun	bez	r18, .L_return
56*4882a593Smuzhiyun.L_set_by_byte_loop:
57*4882a593Smuzhiyun	stb	r1, (r0, 0)
58*4882a593Smuzhiyun	PRE_BNEZAD (r18)
59*4882a593Smuzhiyun	addi	r0, 1
60*4882a593Smuzhiyun	BNEZAD (r18, .L_set_by_byte_loop)
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun.L_return:
63*4882a593Smuzhiyun	mov	r0, r12
64*4882a593Smuzhiyun	rts
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun	/* If dest is not aligned, just set some bytes makes the dest
67*4882a593Smuzhiyun	   align.  */
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun.L_dest_not_aligned:
70*4882a593Smuzhiyun	sub	r13, r19, r13
71*4882a593Smuzhiyun	sub	r2, r13
72*4882a593Smuzhiyun.L_dest_not_aligned_loop:
73*4882a593Smuzhiyun	/* Makes the dest align.  */
74*4882a593Smuzhiyun	stb	r1, (r0, 0)
75*4882a593Smuzhiyun	PRE_BNEZAD (r13)
76*4882a593Smuzhiyun	addi	r0, 1
77*4882a593Smuzhiyun	BNEZAD (r13, .L_dest_not_aligned_loop)
78*4882a593Smuzhiyun	cmplti	r2, 8
79*4882a593Smuzhiyun	bt	.L_set_by_byte
80*4882a593Smuzhiyun	/* Check whether the src is aligned.  */
81*4882a593Smuzhiyun	jbr	.L_dest_aligned
82*4882a593SmuzhiyunENDPROC(memset)
83*4882a593SmuzhiyunENDPROC(__memset)
84