x86: cpa cleanup the 64-bit alias math

 * Modules and drivers should use the set_memory_* APIs instead.

 */

#define HIGH_MAP_START	__START_KERNEL_map

#define HIGH_MAP_END	(__START_KERNEL_map + KERNEL_TEXT_SIZE)

static int

change_page_attr_addr(unsigned long address, pgprot_t mask_set,

		      pgprot_t mask_clr)

{

	int err = 0, kernel_map = 0;

	unsigned long pfn;

	unsigned long phys_addr = __pa(address);

	unsigned long pfn = phys_addr >> PAGE_SHIFT;

	int err;

#ifdef CONFIG_X86_64

	if (address >= __START_KERNEL_map &&

			address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {

		address = (unsigned long)__va(__pa((void *)address));

		kernel_map = 1;

	}

	/*

	 * If we are inside the high mapped kernel range, then we

	 * fixup the low mapping first. __va() returns the virtual

	 * address in the linear mapping:

	 */

	if (within(address, HIGH_MAP_START, HIGH_MAP_END))

		address = (unsigned long) __va(phys_addr);

#endif

	pfn = __pa(address) >> PAGE_SHIFT;

	if (!kernel_map || 1) {

	err = __change_page_attr(address, pfn, mask_set, mask_clr);

	if (err)

		return err;

	}

#ifdef CONFIG_X86_64

	/*

	 * Handle kernel mapping too which aliases part of

	 * lowmem:

	 * If the physical address is inside the kernel map, we need

	 * to touch the high mapped kernel as well:

	 */

	if (__pa(address) < KERNEL_TEXT_SIZE) {

		unsigned long addr2;

		addr2 = __pa(address) + __START_KERNEL_map - phys_base;

	if (within(phys_addr, 0, KERNEL_TEXT_SIZE)) {

		/*

		 * Calc the high mapping address. See __phys_addr()

		 * for the non obvious details.

		 */

		address = phys_addr + HIGH_MAP_START - phys_base;

		/* Make sure the kernel mappings stay executable */

		pgprot_val(mask_clr) |= _PAGE_NX;

		/*

		 * Our high aliases are imprecise, so do not propagate

		 * failures back to users:

		 * Our high aliases are imprecise, because we check

		 * everything between 0 and KERNEL_TEXT_SIZE, so do

		 * not propagate lookup failures back to users:

		 */

		__change_page_attr(addr2, pfn, mask_set, mask_clr);

		__change_page_attr(address, pfn, mask_set, mask_clr);

	}

#endif

	return err;

}