/*
* 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)
