crypto: sun4i-ss - IV register does not work on A10 and A13

Allwinner A10 and A13 SoC have a version of the SS which produce
invalid IV in IVx register.

Instead of adding a variant for those, let's convert SS to produce IV
directly from data.
Fixes: 6298e948 ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Cc: <stable@vger.kernel.org>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c

@@ -20,6 +20,7 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
 	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
 	u32 mode = ctx->mode;
+	void *backup_iv = NULL;
 	/* when activating SS, the default FIFO space is SS_RX_DEFAULT(32) */
 	u32 rx_cnt = SS_RX_DEFAULT;
 	u32 tx_cnt = 0;
@@ -42,6 +43,13 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
 		return -EINVAL;
 	}
 
+	if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
+		backup_iv = kzalloc(ivsize, GFP_KERNEL);
+		if (!backup_iv)
+			return -ENOMEM;
+		scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
+	}
+
 	spin_lock_irqsave(&ss->slock, flags);
 
 	for (i = 0; i < op->keylen; i += 4)
@@ -102,9 +110,12 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
 	} while (oleft);
 
 	if (areq->iv) {
-		for (i = 0; i < 4 && i < ivsize / 4; i++) {
-			v = readl(ss->base + SS_IV0 + i * 4);
-			*(u32 *)(areq->iv + i * 4) = v;
+		if (mode & SS_DECRYPTION) {
+			memcpy(areq->iv, backup_iv, ivsize);
+			kfree_sensitive(backup_iv);
+		} else {
+			scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
+						 ivsize, 0);
 		}
 	}
 
@@ -161,6 +172,7 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 	unsigned int ileft = areq->cryptlen;
 	unsigned int oleft = areq->cryptlen;
 	unsigned int todo;
+	void *backup_iv = NULL;
 	struct sg_mapping_iter mi, mo;
 	unsigned int oi, oo;	/* offset for in and out */
 	unsigned int ob = 0;	/* offset in buf */
@@ -202,6 +214,13 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 	if (need_fallback)
 		return sun4i_ss_cipher_poll_fallback(areq);
 
+	if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
+		backup_iv = kzalloc(ivsize, GFP_KERNEL);
+		if (!backup_iv)
+			return -ENOMEM;
+		scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
+	}
+
 	spin_lock_irqsave(&ss->slock, flags);
 
 	for (i = 0; i < op->keylen; i += 4)
@@ -322,9 +341,12 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 		}
 	}
 	if (areq->iv) {
-		for (i = 0; i < 4 && i < ivsize / 4; i++) {
-			v = readl(ss->base + SS_IV0 + i * 4);
-			*(u32 *)(areq->iv + i * 4) = v;
+		if (mode & SS_DECRYPTION) {
+			memcpy(areq->iv, backup_iv, ivsize);
+			kfree_sensitive(backup_iv);
+		} else {
+			scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
+						 ivsize, 0);
 		}
 	}