1/* SPDX-License-Identifier: GPL-2.0 */
2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4#include <linux/linkage.h>
5#include "sysdep.h"
6
7ENTRY(__memcpy)
8ENTRY(memcpy)
9 /* Test if len less than 4 bytes. */
10 mov r12, r0
11 cmplti r2, 4
12 bt .L_copy_by_byte
13
14 andi r13, r0, 3
15 movi r19, 4
16 /* Test if dest is not 4 bytes aligned. */
17 bnez r13, .L_dest_not_aligned
18
19/* Hardware can handle unaligned access directly. */
20.L_dest_aligned:
21 /* If dest is aligned, then copy. */
22 zext r18, r2, 31, 4
23
24 /* Test if len less than 16 bytes. */
25 bez r18, .L_len_less_16bytes
26 movi r19, 0
27
28 LABLE_ALIGN
29.L_len_larger_16bytes:
30#if defined(__CK860__)
31 ldw r3, (r1, 0)
32 stw r3, (r0, 0)
33 ldw r3, (r1, 4)
34 stw r3, (r0, 4)
35 ldw r3, (r1, 8)
36 stw r3, (r0, 8)
37 ldw r3, (r1, 12)
38 addi r1, 16
39 stw r3, (r0, 12)
40 addi r0, 16
41#else
42 ldw r20, (r1, 0)
43 ldw r21, (r1, 4)
44 ldw r22, (r1, 8)
45 ldw r23, (r1, 12)
46 stw r20, (r0, 0)
47 stw r21, (r0, 4)
48 stw r22, (r0, 8)
49 stw r23, (r0, 12)
50 PRE_BNEZAD (r18)
51 addi r1, 16
52 addi r0, 16
53#endif
54 BNEZAD (r18, .L_len_larger_16bytes)
55
56.L_len_less_16bytes:
57 zext r18, r2, 3, 2
58 bez r18, .L_copy_by_byte
59.L_len_less_16bytes_loop:
60 ldw r3, (r1, 0)
61 PRE_BNEZAD (r18)
62 addi r1, 4
63 stw r3, (r0, 0)
64 addi r0, 4
65 BNEZAD (r18, .L_len_less_16bytes_loop)
66
67/* Test if len less than 4 bytes. */
68.L_copy_by_byte:
69 zext r18, r2, 1, 0
70 bez r18, .L_return
71.L_copy_by_byte_loop:
72 ldb r3, (r1, 0)
73 PRE_BNEZAD (r18)
74 addi r1, 1
75 stb r3, (r0, 0)
76 addi r0, 1
77 BNEZAD (r18, .L_copy_by_byte_loop)
78
79.L_return:
80 mov r0, r12
81 rts
82
83/*
84 * If dest is not aligned, just copying some bytes makes the
85 * dest align.
86 */
87.L_dest_not_aligned:
88 sub r13, r19, r13
89 sub r2, r13
90
91/* Makes the dest align. */
92.L_dest_not_aligned_loop:
93 ldb r3, (r1, 0)
94 PRE_BNEZAD (r13)
95 addi r1, 1
96 stb r3, (r0, 0)
97 addi r0, 1
98 BNEZAD (r13, .L_dest_not_aligned_loop)
99 cmplti r2, 4
100 bt .L_copy_by_byte
101
102 /* Check whether the src is aligned. */
103 jbr .L_dest_aligned
104ENDPROC(__memcpy)
105

source code of linux/arch/csky/abiv2/memcpy.S