random: limit the contribution of the hw rng to at most half

	/*

	 * If we have architectural seed generator, produce a seed and

	 * add it to the pool.  For the sake of paranoia count it as

	 * 50% entropic.

	 * add it to the pool.  For the sake of paranoia don't let the

	 * architectural seed generator dominate the input from the

	 * interrupt noise.

	 */

	if (arch_get_random_seed_long(&seed)) {

		__mix_pool_bytes(r, &seed, sizeof(seed));

		credit += sizeof(seed) * 4;

		credit = 1;

	}

	spin_unlock(&r->lock);

}

#endif

/*

 * Attempt an emergency refill using arch_get_random_seed_long().

 *

 * As with add_interrupt_randomness() be paranoid and only

 * credit the output as 50% entropic.

 */

static int arch_random_refill(void)

{

	const unsigned int nlongs = 64;	/* Arbitrary number */

	unsigned int n = 0;

	unsigned int i;

	unsigned long buf[nlongs];

	if (!arch_has_random_seed())

		return 0;

	for (i = 0; i < nlongs; i++) {

		if (arch_get_random_seed_long(&buf[n]))

			n++;

	}

	if (n) {

		unsigned int rand_bytes = n * sizeof(unsigned long);

		mix_pool_bytes(&input_pool, buf, rand_bytes);

		credit_entropy_bits(&input_pool, rand_bytes*4);

	}

	return n;

}

static ssize_t

_random_read(int nonblock, char __user *buf, size_t nbytes)

{

			return n;

		/* Pool is (near) empty.  Maybe wait and retry. */

		/* First try an emergency refill */

		if (arch_random_refill())

			continue;

		if (nonblock)

			return -EAGAIN;