1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * arch/openrisc/lib/memcpy.c |
4 | * |
5 | * Optimized memory copy routines for openrisc. These are mostly copied |
6 | * from ohter sources but slightly entended based on ideas discuassed in |
7 | * #openrisc. |
8 | * |
9 | * The word unroll implementation is an extension to the arm byte |
10 | * unrolled implementation, but using word copies (if things are |
11 | * properly aligned) |
12 | * |
13 | * The great arm loop unroll algorithm can be found at: |
14 | * arch/arm/boot/compressed/string.c |
15 | */ |
16 | |
17 | #include <linux/export.h> |
18 | |
19 | #include <linux/string.h> |
20 | |
21 | #ifdef CONFIG_OR1K_1200 |
22 | /* |
23 | * Do memcpy with word copies and loop unrolling. This gives the |
24 | * best performance on the OR1200 and MOR1KX archirectures |
25 | */ |
26 | void *memcpy(void *dest, __const void *src, __kernel_size_t n) |
27 | { |
28 | int i = 0; |
29 | unsigned char *d, *s; |
30 | uint32_t *dest_w = (uint32_t *)dest, *src_w = (uint32_t *)src; |
31 | |
32 | /* If both source and dest are word aligned copy words */ |
33 | if (!((unsigned int)dest_w & 3) && !((unsigned int)src_w & 3)) { |
34 | /* Copy 32 bytes per loop */ |
35 | for (i = n >> 5; i > 0; i--) { |
36 | *dest_w++ = *src_w++; |
37 | *dest_w++ = *src_w++; |
38 | *dest_w++ = *src_w++; |
39 | *dest_w++ = *src_w++; |
40 | *dest_w++ = *src_w++; |
41 | *dest_w++ = *src_w++; |
42 | *dest_w++ = *src_w++; |
43 | *dest_w++ = *src_w++; |
44 | } |
45 | |
46 | if (n & 1 << 4) { |
47 | *dest_w++ = *src_w++; |
48 | *dest_w++ = *src_w++; |
49 | *dest_w++ = *src_w++; |
50 | *dest_w++ = *src_w++; |
51 | } |
52 | |
53 | if (n & 1 << 3) { |
54 | *dest_w++ = *src_w++; |
55 | *dest_w++ = *src_w++; |
56 | } |
57 | |
58 | if (n & 1 << 2) |
59 | *dest_w++ = *src_w++; |
60 | |
61 | d = (unsigned char *)dest_w; |
62 | s = (unsigned char *)src_w; |
63 | |
64 | } else { |
65 | d = (unsigned char *)dest_w; |
66 | s = (unsigned char *)src_w; |
67 | |
68 | for (i = n >> 3; i > 0; i--) { |
69 | *d++ = *s++; |
70 | *d++ = *s++; |
71 | *d++ = *s++; |
72 | *d++ = *s++; |
73 | *d++ = *s++; |
74 | *d++ = *s++; |
75 | *d++ = *s++; |
76 | *d++ = *s++; |
77 | } |
78 | |
79 | if (n & 1 << 2) { |
80 | *d++ = *s++; |
81 | *d++ = *s++; |
82 | *d++ = *s++; |
83 | *d++ = *s++; |
84 | } |
85 | } |
86 | |
87 | if (n & 1 << 1) { |
88 | *d++ = *s++; |
89 | *d++ = *s++; |
90 | } |
91 | |
92 | if (n & 1) |
93 | *d++ = *s++; |
94 | |
95 | return dest; |
96 | } |
97 | #else |
98 | /* |
99 | * Use word copies but no loop unrolling as we cannot assume there |
100 | * will be benefits on the archirecture |
101 | */ |
102 | void *memcpy(void *dest, __const void *src, __kernel_size_t n) |
103 | { |
104 | unsigned char *d, *s; |
105 | uint32_t *dest_w = (uint32_t *)dest, *src_w = (uint32_t *)src; |
106 | |
107 | /* If both source and dest are word aligned copy words */ |
108 | if (!((unsigned int)dest_w & 3) && !((unsigned int)src_w & 3)) { |
109 | for (; n >= 4; n -= 4) |
110 | *dest_w++ = *src_w++; |
111 | } |
112 | |
113 | d = (unsigned char *)dest_w; |
114 | s = (unsigned char *)src_w; |
115 | |
116 | /* For remaining or if not aligned, copy bytes */ |
117 | for (; n >= 1; n -= 1) |
118 | *d++ = *s++; |
119 | |
120 | return dest; |
121 | |
122 | } |
123 | #endif |
124 | |
125 | EXPORT_SYMBOL(memcpy); |
126 | |