MIPS: BCM47XX: Slightly clean memory detection

	 * BCM47XX uses 128MB for addressing the ram, if the system contains

	 * less that that amount of ram it remaps the ram more often into the

	 * available space.

	 * Accessing memory after 128MB will cause an exception.

	 * max contains the biggest possible address supported by the platform.

	 * If the method wants to try something above we assume 128MB ram.

	 */

	off = (unsigned long)prom_init;

	max = off | ((128 << 20) - 1);

	for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {

		if ((off + mem) > max) {

			mem = (128 << 20);

	/* Physical address, without mapping to any kernel segment */

	off = CPHYSADDR((unsigned long)prom_init);

	/* Accessing memory after 128 MiB will cause an exception */

	max = 128 << 20;

	for (mem = 1 << 20; mem < max; mem += 1 << 20) {

		/* Loop condition may be not enough, off may be over 1 MiB */

		if (off + mem >= max) {

			mem = max;

			printk(KERN_DEBUG "assume 128MB RAM\n");

			break;

		}