/* | |
* String handling functions. | |
* | |
* Copyright IBM Corp. 2012 | |
*/ | |
#include <linux/linkage.h> | |
/* | |
* memset implementation | |
* | |
* This code corresponds to the C construct below. We do distinguish | |
* between clearing (c == 0) and setting a memory array (c != 0) simply | |
* because nearly all memset invocations in the kernel clear memory and | |
* the xc instruction is preferred in such cases. | |
* | |
* void *memset(void *s, int c, size_t n) | |
* { | |
* if (likely(c == 0)) | |
* return __builtin_memset(s, 0, n); | |
* return __builtin_memset(s, c, n); | |
* } | |
*/ | |
ENTRY(memset) | |
ltgr %r4,%r4 | |
bzr %r14 | |
ltgr %r3,%r3 | |
jnz .Lmemset_fill | |
aghi %r4,-1 | |
srlg %r3,%r4,8 | |
ltgr %r3,%r3 | |
lgr %r1,%r2 | |
jz .Lmemset_clear_rest | |
.Lmemset_clear_loop: | |
xc 0(256,%r1),0(%r1) | |
la %r1,256(%r1) | |
brctg %r3,.Lmemset_clear_loop | |
.Lmemset_clear_rest: | |
larl %r3,.Lmemset_xc | |
ex %r4,0(%r3) | |
br %r14 | |
.Lmemset_fill: | |
stc %r3,0(%r2) | |
cghi %r4,1 | |
lgr %r1,%r2 | |
ber %r14 | |
aghi %r4,-2 | |
srlg %r3,%r4,8 | |
ltgr %r3,%r3 | |
jz .Lmemset_fill_rest | |
.Lmemset_fill_loop: | |
mvc 1(256,%r1),0(%r1) | |
la %r1,256(%r1) | |
brctg %r3,.Lmemset_fill_loop | |
.Lmemset_fill_rest: | |
larl %r3,.Lmemset_mvc | |
ex %r4,0(%r3) | |
br %r14 | |
.Lmemset_xc: | |
xc 0(1,%r1),0(%r1) | |
.Lmemset_mvc: | |
mvc 1(1,%r1),0(%r1) | |
/* | |
* memcpy implementation | |
* | |
* void *memcpy(void *dest, const void *src, size_t n) | |
*/ | |
ENTRY(memcpy) | |
ltgr %r4,%r4 | |
bzr %r14 | |
aghi %r4,-1 | |
srlg %r5,%r4,8 | |
ltgr %r5,%r5 | |
lgr %r1,%r2 | |
jnz .Lmemcpy_loop | |
.Lmemcpy_rest: | |
larl %r5,.Lmemcpy_mvc | |
ex %r4,0(%r5) | |
br %r14 | |
.Lmemcpy_loop: | |
mvc 0(256,%r1),0(%r3) | |
la %r1,256(%r1) | |
la %r3,256(%r3) | |
brctg %r5,.Lmemcpy_loop | |
j .Lmemcpy_rest | |
.Lmemcpy_mvc: | |
mvc 0(1,%r1),0(%r3) |