crypto: marvell/cesa - rearrange handling for hw finished hashes

Rearrange the last request handling for hardware finished hashes
by moving the generation of the fragment operation into this path.
This results in a simplified sequence to handle this case, and
allows us to move the software padded case further down into the
function.  Add comments describing these parts.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c
index 71d29f025bbefd1c3687efa785e4638a034befbd..d282716e0ca7a0468caddb541d2ace5c7f7900c7 100644 (file)
--- a/drivers/crypto/marvell/hash.c
+++ b/drivers/crypto/marvell/hash.c
@@ -529,32 +529,45 @@ mv_cesa_ahash_dma_last_req(struct mv_cesa_tdma_chain *chain,
        struct mv_cesa_op_ctx *op;
        int ret;
 
-       if (frag_len) {
+       /*
+        * If the transfer is smaller than our maximum length, and we have
+        * some data outstanding, we can ask the engine to finish the hash.
+        */
+       if (creq->len <= CESA_SA_DESC_MAC_SRC_TOTAL_LEN_MAX && frag_len) {
                op = mv_cesa_dma_add_frag(chain, &creq->op_tmpl, frag_len,
                                          flags);
                if (IS_ERR(op))
                        return op;
-       } else {
-               op = NULL;
-       }
-
-       if (op && creq->len <= CESA_SA_DESC_MAC_SRC_TOTAL_LEN_MAX) {
-               u32 frag = CESA_SA_DESC_CFG_NOT_FRAG;
-
-               if (!mv_cesa_mac_op_is_first_frag(op))
-                       frag = CESA_SA_DESC_CFG_LAST_FRAG;
 
-               mv_cesa_update_op_cfg(op, frag, CESA_SA_DESC_CFG_FRAG_MSK);
+               mv_cesa_set_mac_op_total_len(op, creq->len);
+               mv_cesa_update_op_cfg(op, mv_cesa_mac_op_is_first_frag(op) ?
+                                               CESA_SA_DESC_CFG_NOT_FRAG :
+                                               CESA_SA_DESC_CFG_LAST_FRAG,
+                                     CESA_SA_DESC_CFG_FRAG_MSK);
 
                return op;
        }
 
+       /*
+        * The request is longer than the engine can handle, or we have
+        * no data outstanding. Manually generate the padding, adding it
+        * as a "mid" fragment.
+        */
        ret = mv_cesa_ahash_dma_alloc_padding(ahashdreq, flags);
        if (ret)
                return ERR_PTR(ret);
 
        trailerlen = mv_cesa_ahash_pad_req(creq, ahashdreq->padding);
 
+       if (frag_len) {
+               op = mv_cesa_dma_add_frag(chain, &creq->op_tmpl, frag_len,
+                                         flags);
+               if (IS_ERR(op))
+                       return op;
+       } else {
+               op = NULL;
+       }
+
        if (op) {
                len = min(CESA_SA_SRAM_PAYLOAD_SIZE - dma_iter->base.op_len,
                          trailerlen);