crypto: ixp4xx - update IV after requests

Crypto selftests fail on ixp4xx since it do not update IV after skcipher
requests.

Fixes: 81bef015 ("crypto: ixp4xx - Hardware crypto support for IXP4xx CPUs")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ixp4xx_crypto.c

@@ -149,6 +149,8 @@ struct crypt_ctl {
 struct ablk_ctx {
 	struct buffer_desc *src;
 	struct buffer_desc *dst;
+	u8 iv[MAX_IVLEN];
+	bool encrypt;
 };
 
 struct aead_ctx {
@@ -381,6 +383,20 @@ static void one_packet(dma_addr_t phys)
 	case CTL_FLAG_PERFORM_ABLK: {
 		struct skcipher_request *req = crypt->data.ablk_req;
 		struct ablk_ctx *req_ctx = skcipher_request_ctx(req);
+		struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+		unsigned int ivsize = crypto_skcipher_ivsize(tfm);
+		unsigned int offset;
+
+		if (ivsize > 0) {
+			offset = req->cryptlen - ivsize;
+			if (req_ctx->encrypt) {
+				scatterwalk_map_and_copy(req->iv, req->dst,
+							 offset, ivsize, 0);
+			} else {
+				memcpy(req->iv, req_ctx->iv, ivsize);
+				memzero_explicit(req_ctx->iv, ivsize);
+			}
+		}
 
 		if (req_ctx->dst) {
 			free_buf_chain(dev, req_ctx->dst, crypt->dst_buf);
@@ -876,6 +892,7 @@ static int ablk_perform(struct skcipher_request *req, int encrypt)
 	struct ablk_ctx *req_ctx = skcipher_request_ctx(req);
 	struct buffer_desc src_hook;
 	struct device *dev = &pdev->dev;
+	unsigned int offset;
 	gfp_t flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 				GFP_KERNEL : GFP_ATOMIC;
 
@@ -885,6 +902,7 @@ static int ablk_perform(struct skcipher_request *req, int encrypt)
 		return -EAGAIN;
 
 	dir = encrypt ? &ctx->encrypt : &ctx->decrypt;
+	req_ctx->encrypt = encrypt;
 
 	crypt = get_crypt_desc();
 	if (!crypt)
@@ -900,6 +918,10 @@ static int ablk_perform(struct skcipher_request *req, int encrypt)
 
 	BUG_ON(ivsize && !req->iv);
 	memcpy(crypt->iv, req->iv, ivsize);
+	if (ivsize > 0 && !encrypt) {
+		offset = req->cryptlen - ivsize;
+		scatterwalk_map_and_copy(req_ctx->iv, req->src, offset, ivsize, 0);
+	}
 	if (req->src != req->dst) {
 		struct buffer_desc dst_hook;
 		crypt->mode |= NPE_OP_NOT_IN_PLACE;