Commit 753d6770 authored by Vladis Dronov's avatar Vladis Dronov Committed by Herbert Xu
Browse files

hwrng: cn10k - Optimize cn10k_rng_read() 



This function assumes that sizeof(void) is 1 and arithmetic works for
void pointers. This is a GNU C extention and may not work with other
compilers. Change this by using an u8 pointer.

Also move cn10k_read_trng() out of a loop thus saving some cycles.

Fixes: 38e9791a ("hwrng: cn10k - Add random number generator support")
Signed-off-by: default avatarVladis Dronov <vdronov@redhat.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 5a6477ea

drivers/char/hw_random/cn10k-rng.c

+10 −6
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ static int cn10k_rng_read(struct hwrng *hwrng, void *data, 
{

	struct cn10k_rng *rng = (struct cn10k_rng *)hwrng->priv;

	unsigned int size;

	u8 *pos = data;

	int err = 0;

	u64 value;
@@ -102,17 +103,20 @@ static int cn10k_rng_read(struct hwrng *hwrng, void *data, 
	while (size >= 8) {

		cn10k_read_trng(rng, &value);



		*((u64 *)data) = (u64)value;

		*((u64 *)pos) = value;

		size -= 8;

		data += 8;

		pos += 8;

	}



	while (size > 0) {

	if (size > 0) {

		cn10k_read_trng(rng, &value);



		*((u8 *)data) = (u8)value;

		while (size > 0) {

			*pos = (u8)value;

			value >>= 8;

			size--;

		data++;

			pos++;

		}

	}



	return max - size;