x86/kaslr: Simplify process_gb_huge_pages()

static void

process_gb_huge_pages(struct mem_vector *region, unsigned long image_size)

{

	unsigned long addr, size = 0;

	unsigned long pud_start, pud_end, gb_huge_pages;

	struct mem_vector tmp;

	int i = 0;

	if (!IS_ENABLED(CONFIG_X86_64) || !max_gb_huge_pages) {

		store_slot_info(region, image_size);

		return;

	}

	addr = ALIGN(region->start, PUD_SIZE);

	/* Did we raise the address above the passed in memory entry? */

	if (addr < region->start + region->size)

		size = region->size - (addr - region->start);

	/* Check how many 1GB huge pages can be filtered out: */

	while (size >= PUD_SIZE && max_gb_huge_pages) {

		size -= PUD_SIZE;

		max_gb_huge_pages--;

		i++;

	}

	/* Are there any 1GB pages in the region? */

	pud_start = ALIGN(region->start, PUD_SIZE);

	pud_end = ALIGN_DOWN(region->start + region->size, PUD_SIZE);

	/* No good 1GB huge pages found: */

	if (!i) {

	if (pud_start >= pud_end) {

		store_slot_info(region, image_size);

		return;

	}

	/*

	 * Skip those 'i'*1GB good huge pages, and continue checking and

	 * processing the remaining head or tail part of the passed region

	 * if available.

	 */

	if (addr >= region->start + image_size) {

	/* Check if the head part of the region is usable. */

	if (pud_start >= region->start + image_size) {

		tmp.start = region->start;

		tmp.size = addr - region->start;

		tmp.size = pud_start - region->start;

		store_slot_info(&tmp, image_size);

	}

	size  = region->size - (addr - region->start) - i * PUD_SIZE;

	if (size >= image_size) {

		tmp.start = addr + i * PUD_SIZE;

		tmp.size = size;

	/* Skip the good 1GB pages. */

	gb_huge_pages = (pud_end - pud_start) >> PUD_SHIFT;

	if (gb_huge_pages > max_gb_huge_pages) {

		pud_end = pud_start + (max_gb_huge_pages << PUD_SHIFT);

		max_gb_huge_pages = 0;

	} else {

		max_gb_huge_pages -= gb_huge_pages;

	}

	/* Check if the tail part of the region is usable. */

	if (region->start + region->size >= pud_end + image_size) {

		tmp.start = pud_end;

		tmp.size = region->start + region->size - pud_end;

		store_slot_info(&tmp, image_size);

	}

}