crypto: omap-sham - fix split update cases with cryptomgr tests

The updated crypto manager finds a couple of new bugs from the omap-sham
driver. Basically the split update cases fail to calculate the amount of
data to be sent properly, leading into failed results and hangs with the
hw accelerator.

To fix these, the buffer handling needs to be fixed, but we do some cleanup
for the code at the same time to cut away some unnecessary code so that
it is easier to fix.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-sham.c

@@ -648,6 +648,8 @@ static int omap_sham_copy_sg_lists(struct omap_sham_reqctx *ctx,
 	struct scatterlist *tmp;
 	int offset = ctx->offset;
 
+	ctx->total = new_len;
+
 	if (ctx->bufcnt)
 		n++;
 
@@ -665,6 +667,7 @@ static int omap_sham_copy_sg_lists(struct omap_sham_reqctx *ctx,
 		sg_set_buf(tmp, ctx->dd->xmit_buf, ctx->bufcnt);
 		tmp = sg_next(tmp);
 		ctx->sg_len++;
+		new_len -= ctx->bufcnt;
 	}
 
 	while (sg && new_len) {
@@ -682,15 +685,18 @@ static int omap_sham_copy_sg_lists(struct omap_sham_reqctx *ctx,
 		if (len > 0) {
 			new_len -= len;
 			sg_set_page(tmp, sg_page(sg), len, sg->offset);
+			ctx->sg_len++;
 			if (new_len <= 0)
-				sg_mark_end(tmp);
+				break;
 			tmp = sg_next(tmp);
-			ctx->sg_len++;
 		}
 
 		sg = sg_next(sg);
 	}
 
+	if (tmp)
+		sg_mark_end(tmp);
+
 	set_bit(FLAGS_SGS_ALLOCED, &ctx->dd->flags);
 
 	ctx->offset += new_len - ctx->bufcnt;
@@ -726,6 +732,7 @@ static int omap_sham_copy_sgs(struct omap_sham_reqctx *ctx,
 	ctx->sg_len = 1;
 	ctx->offset += new_len - ctx->bufcnt;
 	ctx->bufcnt = 0;
+	ctx->total = new_len;
 
 	return 0;
 }
@@ -771,6 +778,9 @@ static int omap_sham_align_sgs(struct scatterlist *sg,
 			}
 			nbytes -= bufcnt;
 			bufcnt = 0;
+			if (!nbytes)
+				list_ok = false;
+
 			continue;
 		}
 
@@ -820,9 +830,9 @@ static int omap_sham_align_sgs(struct scatterlist *sg,
 		return omap_sham_copy_sgs(rctx, sg, bs, new_len);
 	else if (!list_ok)
 		return omap_sham_copy_sg_lists(rctx, sg, bs, new_len);
-	else
-		rctx->offset += new_len;
 
+	rctx->total = new_len;
+	rctx->offset += new_len;
 	rctx->sg_len = n;
 	rctx->sg = sg;
 
@@ -834,99 +844,54 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update)
 	struct omap_sham_reqctx *rctx = ahash_request_ctx(req);
 	int bs;
 	int ret;
-	int nbytes;
+	unsigned int nbytes;
 	bool final = rctx->flags & BIT(FLAGS_FINUP);
-	int xmit_len, hash_later;
+	int hash_later;
 
 	bs = get_block_size(rctx);
 
-	if (update)
-		nbytes = req->nbytes;
-	else
-		nbytes = 0;
+	nbytes = rctx->bufcnt;
 
-	rctx->total = nbytes + rctx->bufcnt - rctx->offset;
+	if (update)
+		nbytes += req->nbytes - rctx->offset;
 
 	dev_dbg(rctx->dd->dev,
 		"%s: nbytes=%d, bs=%d, total=%d, offset=%d, bufcnt=%d\n",
 		__func__, nbytes, bs, rctx->total, rctx->offset,
 		rctx->bufcnt);
 
-	if (!rctx->total)
+	if (!nbytes)
 		return 0;
 
-	if (nbytes && (!IS_ALIGNED(rctx->bufcnt, bs))) {
+	rctx->total = nbytes;
+
+	if (update && req->nbytes && (!IS_ALIGNED(rctx->bufcnt, bs))) {
 		int len = bs - rctx->bufcnt % bs;
 
-		if (len > nbytes)
-			len = nbytes;
+		if (len > req->nbytes)
+			len = req->nbytes;
 		scatterwalk_map_and_copy(rctx->buffer + rctx->bufcnt, req->src,
 					 0, len, 0);
 		rctx->bufcnt += len;
-		nbytes -= len;
 		rctx->offset = len;
 	}
 
 	if (rctx->bufcnt)
 		memcpy(rctx->dd->xmit_buf, rctx->buffer, rctx->bufcnt);
 
-	ret = omap_sham_align_sgs(req->src, rctx->total, bs, final, rctx);
+	ret = omap_sham_align_sgs(req->src, nbytes, bs, final, rctx);
 	if (ret)
 		return ret;
 
-	xmit_len = rctx->total;
-
-	if (xmit_len > OMAP_SHA_MAX_DMA_LEN)
-		xmit_len = OMAP_SHA_MAX_DMA_LEN;
-
-	if (!IS_ALIGNED(xmit_len, bs)) {
-		if (final)
-			xmit_len = DIV_ROUND_UP(xmit_len, bs) * bs;
-		else
-			xmit_len = xmit_len / bs * bs;
-	} else if (!final && rctx->total == xmit_len) {
-		xmit_len -= bs;
-	}
-
-	hash_later = rctx->total - xmit_len;
+	hash_later = nbytes - rctx->total;
 	if (hash_later < 0)
 		hash_later = 0;
 
-	if (rctx->bufcnt && nbytes) {
-		/* have data from previous operation and current */
-		sg_init_table(rctx->sgl, 2);
-		sg_set_buf(rctx->sgl, rctx->dd->xmit_buf, rctx->bufcnt);
-
-		sg_chain(rctx->sgl, 2, req->src);
-
-		rctx->sg = rctx->sgl;
-
-		rctx->sg_len++;
-	} else if (rctx->bufcnt) {
-		/* have buffered data only */
-		sg_init_table(rctx->sgl, 1);
-		sg_set_buf(rctx->sgl, rctx->dd->xmit_buf, xmit_len);
-
-		rctx->sg = rctx->sgl;
-
-		rctx->sg_len = 1;
-	}
-
-	if (hash_later && hash_later <= rctx->buflen) {
-		int offset = 0;
-
-		if (hash_later > req->nbytes) {
-			memcpy(rctx->buffer, rctx->buffer + xmit_len,
-			       hash_later - req->nbytes);
-			offset = hash_later - req->nbytes;
-		}
-
-		if (req->nbytes) {
-			scatterwalk_map_and_copy(rctx->buffer + offset,
+	if (hash_later) {
+		scatterwalk_map_and_copy(rctx->buffer,
 					 req->src,
-						 offset + req->nbytes -
-						 hash_later, hash_later, 0);
-		}
+					 req->nbytes - hash_later,
+					 hash_later, 0);
 
 		rctx->bufcnt = hash_later;
 	} else {
@@ -936,8 +901,7 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update)
 	if (hash_later > rctx->buflen)
 		set_bit(FLAGS_HUGE, &rctx->dd->flags);
 
-	if (!final)
-		rctx->total = xmit_len;
+	rctx->total = min(nbytes, rctx->total);
 
 	return 0;
 }