void _memset_c_io()

in kernel/io.c [575:629]

• 41 lines of code
• 12 McCabe index (conditional complexity)

void _memset_c_io(volatile void __iomem *to, unsigned long c, long count)
{
	/* Handle any initial odd byte */
	if (count > 0 && ((u64)to & 1)) {
		__raw_writeb(c, to);
		to++;
		count--;
	}

	/* Handle any initial odd halfword */
	if (count >= 2 && ((u64)to & 2)) {
		__raw_writew(c, to);
		to += 2;
		count -= 2;
	}

	/* Handle any initial odd word */
	if (count >= 4 && ((u64)to & 4)) {
		__raw_writel(c, to);
		to += 4;
		count -= 4;
	}

	/* Handle all full-sized quadwords: we're aligned
	   (or have a small count) */
	count -= 8;
	if (count >= 0) {
		do {
			__raw_writeq(c, to);
			to += 8;
			count -= 8;
		} while (count >= 0);
	}
	count += 8;

	/* The tail is word-aligned if we still have count >= 4 */
	if (count >= 4) {
		__raw_writel(c, to);
		to += 4;
		count -= 4;
	}

	/* The tail is half-word aligned if we have count >= 2 */
	if (count >= 2) {
		__raw_writew(c, to);
		to += 2;
		count -= 2;
	}

	/* And finally, one last byte.. */
	if (count) {
		__raw_writeb(c, to);
	}
	mb();
}