projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 535c611d HC |
1 | /* |
| 2 | * String handling functions. | |
| 3 | * | |
| 4 | * Copyright IBM Corp. 2012 | |
| 5 | */ | |
| 6 | ||
| 7 | #include <linux/linkage.h> | |
| 711f5df7 | 8 | #include <asm/export.h> |
| 535c611d HC |
9 | |
| 10 | /* | |
| 11 | * memset implementation | |
| 12 | * | |
| 13 | * This code corresponds to the C construct below. We do distinguish | |
| 14 | * between clearing (c == 0) and setting a memory array (c != 0) simply | |
| 15 | * because nearly all memset invocations in the kernel clear memory and | |
| 16 | * the xc instruction is preferred in such cases. | |
| 17 | * | |
| 18 | * void *memset(void *s, int c, size_t n) | |
| 19 | * { | |
| 20 | * if (likely(c == 0)) | |
| 21 | * return __builtin_memset(s, 0, n); | |
| 22 | * return __builtin_memset(s, c, n); | |
| 23 | * } | |
| 24 | */ | |
| 25 | ENTRY(memset) | |
| 26 | ltgr %r4,%r4 | |
| 27 | bzr %r14 | |
| 28 | ltgr %r3,%r3 | |
| 29 | jnz .Lmemset_fill | |
| 30 | aghi %r4,-1 | |
| 31 | srlg %r3,%r4,8 | |
| 32 | ltgr %r3,%r3 | |
| 33 | lgr %r1,%r2 | |
| 34 | jz .Lmemset_clear_rest | |
| 35 | .Lmemset_clear_loop: | |
| 36 | xc 0(256,%r1),0(%r1) | |
| 37 | la %r1,256(%r1) | |
| 38 | brctg %r3,.Lmemset_clear_loop | |
| 39 | .Lmemset_clear_rest: | |
| 40 | larl %r3,.Lmemset_xc | |
| 41 | ex %r4,0(%r3) | |
| 42 | br %r14 | |
| 43 | .Lmemset_fill: | |
| 44 | stc %r3,0(%r2) | |
| 45 | cghi %r4,1 | |
| 46 | lgr %r1,%r2 | |
| 47 | ber %r14 | |
| 48 | aghi %r4,-2 | |
| 49 | srlg %r3,%r4,8 | |
| 50 | ltgr %r3,%r3 | |
| 51 | jz .Lmemset_fill_rest | |
| 52 | .Lmemset_fill_loop: | |
| 53 | mvc 1(256,%r1),0(%r1) | |
| 54 | la %r1,256(%r1) | |
| 55 | brctg %r3,.Lmemset_fill_loop | |
| 56 | .Lmemset_fill_rest: | |
| 57 | larl %r3,.Lmemset_mvc | |
| 58 | ex %r4,0(%r3) | |
| 59 | br %r14 | |
| 60 | .Lmemset_xc: | |
| 61 | xc 0(1,%r1),0(%r1) | |
| 62 | .Lmemset_mvc: | |
| 63 | mvc 1(1,%r1),0(%r1) | |
| 711f5df7 | 64 | EXPORT_SYMBOL(memset) |
| 535c611d HC |
65 | |
| 66 | /* | |
| 67 | * memcpy implementation | |
| 68 | * | |
| 69 | * void *memcpy(void *dest, const void *src, size_t n) | |
| 70 | */ | |
| 71 | ENTRY(memcpy) | |
| 72 | ltgr %r4,%r4 | |
| 73 | bzr %r14 | |
| 74 | aghi %r4,-1 | |
| 75 | srlg %r5,%r4,8 | |
| 76 | ltgr %r5,%r5 | |
| 77 | lgr %r1,%r2 | |
| 78 | jnz .Lmemcpy_loop | |
| 79 | .Lmemcpy_rest: | |
| 80 | larl %r5,.Lmemcpy_mvc | |
| 81 | ex %r4,0(%r5) | |
| 82 | br %r14 | |
| 83 | .Lmemcpy_loop: | |
| 84 | mvc 0(256,%r1),0(%r3) | |
| 85 | la %r1,256(%r1) | |
| 86 | la %r3,256(%r3) | |
| 87 | brctg %r5,.Lmemcpy_loop | |
| 88 | j .Lmemcpy_rest | |
| 89 | .Lmemcpy_mvc: | |
| 90 | mvc 0(1,%r1),0(%r3) | |
| 711f5df7 | 91 | EXPORT_SYMBOL(memcpy) |