powerpc/mm/hash: Refactor hash__mark_rodata_ro()

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#ifdef CONFIG_STRICT_KERNEL_RWX

void hash__mark_rodata_ro(void)

static bool hash__change_memory_range(unsigned long start, unsigned long end,

				      unsigned long newpp)

{

	unsigned long start = (unsigned long)_stext;

	unsigned long end = (unsigned long)__init_begin;

	unsigned long idx;

	unsigned int step, shift;

	unsigned long newpp = PP_RXXX;

	shift = mmu_psize_defs[mmu_linear_psize].shift;

	step = 1 << shift;

	start = ((start + step - 1) >> shift) << shift;

	end = (end >> shift) << shift;

	start = ALIGN_DOWN(start, step);

	end = ALIGN(end, step); // aligns up

	pr_devel("marking ro start %lx, end %lx, step %x\n",

			start, end, step);

	if (start >= end)

		return false;

	if (start == end) {

		pr_warn("could not set rodata ro, relocate the start"

			" of the kernel to a 0x%x boundary\n", step);

		return;

	}

	pr_debug("Changing page protection on range 0x%lx-0x%lx, to 0x%lx, step 0x%x\n",

		 start, end, newpp, step);

	for (idx = start; idx < end; idx += step)

		/* Not sure if we can do much with the return value */

		mmu_hash_ops.hpte_updateboltedpp(newpp, idx, mmu_linear_psize,

							mmu_kernel_ssize);

	return true;

}

void hash__mark_rodata_ro(void)

{

	unsigned long start, end;

	start = (unsigned long)_stext;

	end = (unsigned long)__init_begin;

	WARN_ON(!hash__change_memory_range(start, end, PP_RXXX));

}

#endif