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Commit | Line | Data |
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535c611d HC |
1 | /* |
2 | * String handling functions. | |
3 | * | |
4 | * Copyright IBM Corp. 2012 | |
5 | */ | |
6 | ||
7 | #include <linux/linkage.h> | |
8 | ||
9 | /* | |
10 | * memset implementation | |
11 | * | |
12 | * This code corresponds to the C construct below. We do distinguish | |
13 | * between clearing (c == 0) and setting a memory array (c != 0) simply | |
14 | * because nearly all memset invocations in the kernel clear memory and | |
15 | * the xc instruction is preferred in such cases. | |
16 | * | |
17 | * void *memset(void *s, int c, size_t n) | |
18 | * { | |
19 | * if (likely(c == 0)) | |
20 | * return __builtin_memset(s, 0, n); | |
21 | * return __builtin_memset(s, c, n); | |
22 | * } | |
23 | */ | |
24 | ENTRY(memset) | |
25 | basr %r5,%r0 | |
26 | .Lmemset_base: | |
27 | ltr %r4,%r4 | |
28 | bzr %r14 | |
29 | ltr %r3,%r3 | |
30 | jnz .Lmemset_fill | |
31 | ahi %r4,-1 | |
32 | lr %r3,%r4 | |
33 | srl %r3,8 | |
34 | ltr %r3,%r3 | |
35 | lr %r1,%r2 | |
36 | je .Lmemset_clear_rest | |
37 | .Lmemset_clear_loop: | |
38 | xc 0(256,%r1),0(%r1) | |
39 | la %r1,256(%r1) | |
40 | brct %r3,.Lmemset_clear_loop | |
41 | .Lmemset_clear_rest: | |
42 | ex %r4,.Lmemset_xc-.Lmemset_base(%r5) | |
43 | br %r14 | |
44 | .Lmemset_fill: | |
45 | stc %r3,0(%r2) | |
46 | chi %r4,1 | |
47 | lr %r1,%r2 | |
48 | ber %r14 | |
49 | ahi %r4,-2 | |
50 | lr %r3,%r4 | |
51 | srl %r3,8 | |
52 | ltr %r3,%r3 | |
53 | je .Lmemset_fill_rest | |
54 | .Lmemset_fill_loop: | |
55 | mvc 1(256,%r1),0(%r1) | |
56 | la %r1,256(%r1) | |
57 | brct %r3,.Lmemset_fill_loop | |
58 | .Lmemset_fill_rest: | |
59 | ex %r4,.Lmemset_mvc-.Lmemset_base(%r5) | |
60 | br %r14 | |
61 | .Lmemset_xc: | |
62 | xc 0(1,%r1),0(%r1) | |
63 | .Lmemset_mvc: | |
64 | mvc 1(1,%r1),0(%r1) | |
65 | ||
66 | /* | |
67 | * memcpy implementation | |
68 | * | |
69 | * void *memcpy(void *dest, const void *src, size_t n) | |
70 | */ | |
71 | ENTRY(memcpy) | |
72 | basr %r5,%r0 | |
73 | .Lmemcpy_base: | |
74 | ltr %r4,%r4 | |
75 | bzr %r14 | |
76 | ahi %r4,-1 | |
77 | lr %r0,%r4 | |
78 | srl %r0,8 | |
79 | ltr %r0,%r0 | |
80 | lr %r1,%r2 | |
81 | jnz .Lmemcpy_loop | |
82 | .Lmemcpy_rest: | |
83 | ex %r4,.Lmemcpy_mvc-.Lmemcpy_base(%r5) | |
84 | br %r14 | |
85 | .Lmemcpy_loop: | |
86 | mvc 0(256,%r1),0(%r3) | |
87 | la %r1,256(%r1) | |
88 | la %r3,256(%r3) | |
89 | brct %r0,.Lmemcpy_loop | |
90 | j .Lmemcpy_rest | |
91 | .Lmemcpy_mvc: | |
92 | mvc 0(1,%r1),0(%r3) |