diff options
Diffstat (limited to 'arch/s390/lib/mem32.S')
-rw-r--r-- | arch/s390/lib/mem32.S | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/s390/lib/mem32.S b/arch/s390/lib/mem32.S new file mode 100644 index 000000000000..14ca9244b615 --- /dev/null +++ b/arch/s390/lib/mem32.S | |||
@@ -0,0 +1,92 @@ | |||
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) | ||