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 */
24ENTRY(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 */
71ENTRY(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)