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Diffstat (limited to 'arch/microblaze/lib/memset.c')
-rw-r--r-- | arch/microblaze/lib/memset.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/microblaze/lib/memset.c b/arch/microblaze/lib/memset.c new file mode 100644 index 0000000000..7c2352d56b --- /dev/null +++ b/arch/microblaze/lib/memset.c @@ -0,0 +1,94 @@ +/* + * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2008-2009 PetaLogix + * Copyright (C) 2007 John Williams + * + * Reasonably optimised generic C-code for memset on Microblaze + * This is generic C code to do efficient, alignment-aware memcpy. + * + * It is based on demo code originally Copyright 2001 by Intel Corp, taken from + * http://www.embedded.com/showArticle.jhtml?articleID=19205567 + * + * Attempts were made, unsuccessfully, to contact the original + * author of this code (Michael Morrow, Intel). Below is the original + * copyright notice. + * + * This software has been developed by Intel Corporation. + * Intel specifically disclaims all warranties, express or + * implied, and all liability, including consequential and + * other indirect damages, for the use of this program, including + * liability for infringement of any proprietary rights, + * and including the warranties of merchantability and fitness + * for a particular purpose. Intel does not assume any + * responsibility for and errors which may appear in this program + * not any responsibility to update it. + */ + +#include <linux/export.h> +#include <linux/types.h> +#include <linux/stddef.h> +#include <linux/compiler.h> +#include <linux/string.h> + +#ifdef CONFIG_OPT_LIB_FUNCTION +void *memset(void *v_src, int c, __kernel_size_t n) +{ + char *src = v_src; + uint32_t *i_src; + uint32_t w32 = 0; + + /* Truncate c to 8 bits */ + c = (c & 0xFF); + + if (unlikely(c)) { + /* Make a repeating word out of it */ + w32 = c; + w32 |= w32 << 8; + w32 |= w32 << 16; + } + + if (likely(n >= 4)) { + /* Align the destination to a word boundary */ + /* This is done in an endian independent manner */ + switch ((unsigned) src & 3) { + case 1: + *src++ = c; + --n; + fallthrough; + case 2: + *src++ = c; + --n; + fallthrough; + case 3: + *src++ = c; + --n; + } + + i_src = (void *)src; + + /* Do as many full-word copies as we can */ + for (; n >= 4; n -= 4) + *i_src++ = w32; + + src = (void *)i_src; + } + + /* Simple, byte oriented memset or the rest of count. */ + switch (n) { + case 3: + *src++ = c; + fallthrough; + case 2: + *src++ = c; + fallthrough; + case 1: + *src++ = c; + break; + default: + break; + } + + return v_src; +} +EXPORT_SYMBOL(memset); +#endif /* CONFIG_OPT_LIB_FUNCTION */ |