Commit | Line | Data |
---|---|---|
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 | ltgr %r4,%r4 | |
26 | bzr %r14 | |
27 | ltgr %r3,%r3 | |
28 | jnz .Lmemset_fill | |
29 | aghi %r4,-1 | |
30 | srlg %r3,%r4,8 | |
31 | ltgr %r3,%r3 | |
32 | lgr %r1,%r2 | |
33 | jz .Lmemset_clear_rest | |
34 | .Lmemset_clear_loop: | |
35 | xc 0(256,%r1),0(%r1) | |
36 | la %r1,256(%r1) | |
37 | brctg %r3,.Lmemset_clear_loop | |
38 | .Lmemset_clear_rest: | |
39 | larl %r3,.Lmemset_xc | |
40 | ex %r4,0(%r3) | |
41 | br %r14 | |
42 | .Lmemset_fill: | |
43 | stc %r3,0(%r2) | |
44 | cghi %r4,1 | |
45 | lgr %r1,%r2 | |
46 | ber %r14 | |
47 | aghi %r4,-2 | |
48 | srlg %r3,%r4,8 | |
49 | ltgr %r3,%r3 | |
50 | jz .Lmemset_fill_rest | |
51 | .Lmemset_fill_loop: | |
52 | mvc 1(256,%r1),0(%r1) | |
53 | la %r1,256(%r1) | |
54 | brctg %r3,.Lmemset_fill_loop | |
55 | .Lmemset_fill_rest: | |
56 | larl %r3,.Lmemset_mvc | |
57 | ex %r4,0(%r3) | |
58 | br %r14 | |
59 | .Lmemset_xc: | |
60 | xc 0(1,%r1),0(%r1) | |
61 | .Lmemset_mvc: | |
62 | mvc 1(1,%r1),0(%r1) | |
63 | ||
64 | /* | |
65 | * memcpy implementation | |
66 | * | |
67 | * void *memcpy(void *dest, const void *src, size_t n) | |
68 | */ | |
69 | ENTRY(memcpy) | |
70 | ltgr %r4,%r4 | |
71 | bzr %r14 | |
72 | aghi %r4,-1 | |
73 | srlg %r5,%r4,8 | |
74 | ltgr %r5,%r5 | |
75 | lgr %r1,%r2 | |
76 | jnz .Lmemcpy_loop | |
77 | .Lmemcpy_rest: | |
78 | larl %r5,.Lmemcpy_mvc | |
79 | ex %r4,0(%r5) | |
80 | br %r14 | |
81 | .Lmemcpy_loop: | |
82 | mvc 0(256,%r1),0(%r3) | |
83 | la %r1,256(%r1) | |
84 | la %r3,256(%r3) | |
85 | brctg %r5,.Lmemcpy_loop | |
86 | j .Lmemcpy_rest | |
87 | .Lmemcpy_mvc: | |
88 | mvc 0(1,%r1),0(%r3) |