diff --git a/lib/string.c b/lib/string.c index 4288e0158..cc89311bf 100755 --- a/lib/string.c +++ b/lib/string.c @@ -796,10 +796,38 @@ EXPORT_SYMBOL(__sysfs_match_string); */ void *memset(void *s, int c, size_t count) { - char *xs = s; + union types dest = { .as_u8 = s }; + if (count >= MIN_THRESHOLD) { + unsigned long cu = (unsigned long)c; + + /* Compose an ulong with 'c' repeated 4/8 times */ +#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER + cu *= 0x0101010101010101UL; +#else + cu |= cu << 8; + cu |= cu << 16; + /* Suppress warning on 32 bit machines */ + cu |= (cu << 16) << 16; +#endif + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) { + /* + * Fill the buffer one byte at time until + * the destination is word aligned. + */ + for (; count && dest.as_uptr & WORD_MASK; count--) + *dest.as_u8++ = c; + } + + /* Copy using the largest size allowed */ + for (; count >= BYTES_LONG; count -= BYTES_LONG) + *dest.as_ulong++ = cu; + } + + /* copy the remainder */ while (count--) - *xs++ = c; + *dest.as_u8++ = c; + return s; } EXPORT_SYMBOL(memset);