crypto: keembay - use 64-bit arithmetic for computing bit_len

src_size and aad_size are defined as u32, so the following expressions are
currently being evaluated using 32-bit arithmetic:

bit_len = src_size * 8;
...
bit_len = aad_size * 8;

However, bit_len is used afterwards in a context that expects a valid
64-bit value (the lower and upper 32-bit words of bit_len are extracted
and written to hw).

In order to make sure the correct bit length is generated and the 32-bit
multiplication does not wrap around, cast src_size and aad_size to u64.
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Acked-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/keembay/ocs-aes.c

@@ -958,14 +958,14 @@ int ocs_aes_gcm_op(struct ocs_aes_dev *aes_dev,
 	ocs_aes_write_last_data_blk_len(aes_dev, src_size);
 
 	/* Write ciphertext bit length */
-	bit_len = src_size * 8;
+	bit_len = (u64)src_size * 8;
 	val = bit_len & 0xFFFFFFFF;
 	iowrite32(val, aes_dev->base_reg + AES_MULTIPURPOSE2_0_OFFSET);
 	val = bit_len >> 32;
 	iowrite32(val, aes_dev->base_reg + AES_MULTIPURPOSE2_1_OFFSET);
 
 	/* Write aad bit length */
-	bit_len = aad_size * 8;
+	bit_len = (u64)aad_size * 8;
 	val = bit_len & 0xFFFFFFFF;
 	iowrite32(val, aes_dev->base_reg + AES_MULTIPURPOSE2_2_OFFSET);
 	val = bit_len >> 32;