crypto: artpec6 - set correct iv size for gcm(aes)

The IV size should not include the 32 bit counter. Because we had the
IV size set as 16 the transform only worked when the IV input was zero
padded.

Fixes: a21eb94fc4d3 ("crypto: axis - add ARTPEC-6/7 crypto accelerator driver")
Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/axis/artpec6_crypto.c

@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 
 #include <crypto/aes.h>
+#include <crypto/gcm.h>
 #include <crypto/internal/aead.h>
 #include <crypto/internal/hash.h>
 #include <crypto/internal/skcipher.h>
@@ -1934,7 +1935,7 @@ static int artpec6_crypto_prepare_aead(struct aead_request *areq)
 
 	memcpy(req_ctx->hw_ctx.J0, areq->iv, crypto_aead_ivsize(cipher));
 	// The HW omits the initial increment of the counter field.
-	crypto_inc(req_ctx->hw_ctx.J0+12, 4);
+	memcpy(req_ctx->hw_ctx.J0 + GCM_AES_IV_SIZE, "\x00\x00\x00\x01", 4);
 
 	ret = artpec6_crypto_setup_out_descr(common, &req_ctx->hw_ctx,
 		sizeof(struct artpec6_crypto_aead_hw_ctx), false, false);
@@ -2956,7 +2957,7 @@ static struct aead_alg aead_algos[] = {
 		.setkey = artpec6_crypto_aead_set_key,
 		.encrypt = artpec6_crypto_aead_encrypt,
 		.decrypt = artpec6_crypto_aead_decrypt,
-		.ivsize = AES_BLOCK_SIZE,
+		.ivsize = GCM_AES_IV_SIZE,
 		.maxauthsize = AES_BLOCK_SIZE,
 
 		.base = {