1/*
2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2008-2009 PetaLogix
4 * Copyright (C) 2007 John Williams
5 *
6 * Reasonably optimised generic C-code for memset on Microblaze
7 * This is generic C code to do efficient, alignment-aware memcpy.
8 *
9 * It is based on demo code originally Copyright 2001 by Intel Corp, taken from
10 * http://www.embedded.com/showArticle.jhtml?articleID=19205567
11 *
12 * Attempts were made, unsuccessfully, to contact the original
13 * author of this code (Michael Morrow, Intel).  Below is the original
14 * copyright notice.
15 *
16 * This software has been developed by Intel Corporation.
17 * Intel specifically disclaims all warranties, express or
18 * implied, and all liability, including consequential and
19 * other indirect damages, for the use of this program, including
20 * liability for infringement of any proprietary rights,
21 * and including the warranties of merchantability and fitness
22 * for a particular purpose. Intel does not assume any
23 * responsibility for and errors which may appear in this program
24 * not any responsibility to update it.
25 */
26
27#include <linux/export.h>
28#include <linux/types.h>
29#include <linux/stddef.h>
30#include <linux/compiler.h>
31#include <linux/string.h>
32
33#ifdef __HAVE_ARCH_MEMSET
34#ifndef CONFIG_OPT_LIB_FUNCTION
35void *memset(void *v_src, int c, __kernel_size_t n)
36{
37	char *src = v_src;
38
39	/* Truncate c to 8 bits */
40	c = (c & 0xFF);
41
42	/* Simple, byte oriented memset or the rest of count. */
43	while (n--)
44		*src++ = c;
45
46	return v_src;
47}
48#else /* CONFIG_OPT_LIB_FUNCTION */
49void *memset(void *v_src, int c, __kernel_size_t n)
50{
51	char *src = v_src;
52	uint32_t *i_src;
53	uint32_t w32 = 0;
54
55	/* Truncate c to 8 bits */
56	c = (c & 0xFF);
57
58	if (unlikely(c)) {
59		/* Make a repeating word out of it */
60		w32 = c;
61		w32 |= w32 << 8;
62		w32 |= w32 << 16;
63	}
64
65	if (likely(n >= 4)) {
66		/* Align the destination to a word boundary */
67		/* This is done in an endian independent manner */
68		switch ((unsigned) src & 3) {
69		case 1:
70			*src++ = c;
71			--n;
72		case 2:
73			*src++ = c;
74			--n;
75		case 3:
76			*src++ = c;
77			--n;
78		}
79
80		i_src  = (void *)src;
81
82		/* Do as many full-word copies as we can */
83		for (; n >= 4; n -= 4)
84			*i_src++ = w32;
85
86		src  = (void *)i_src;
87	}
88
89	/* Simple, byte oriented memset or the rest of count. */
90	while (n--)
91		*src++ = c;
92
93	return v_src;
94}
95#endif /* CONFIG_OPT_LIB_FUNCTION */
96EXPORT_SYMBOL(memset);
97#endif /* __HAVE_ARCH_MEMSET */
98