crypto: talitos - fix ahash for multiple of blocksize

Correct ahash_process_req() to properly handle cases
where the total hash amount is a multiple of the blocksize.
The SEC must have some data to hash during the very last
descriptor operation; so up to one whole blocksize
of data is buffered until the final hash.

Signed-off-by: Lee Nipper <lee.nipper@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index 637c105..0f2483e 100644 (file)
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -720,7 +720,6 @@ struct talitos_ctx {
 #define TALITOS_MDEU_MAX_CONTEXT_SIZE  TALITOS_MDEU_CONTEXT_SIZE_SHA384_SHA512
 
 struct talitos_ahash_req_ctx {
-       u64 count;
        u32 hw_context[TALITOS_MDEU_MAX_CONTEXT_SIZE / sizeof(u32)];
        unsigned int hw_context_size;
        u8 buf[HASH_MAX_BLOCK_SIZE];
@@ -729,6 +728,7 @@ struct talitos_ahash_req_ctx {
        unsigned int first;
        unsigned int last;
        unsigned int to_hash_later;
+       u64 nbuf;
        struct scatterlist bufsl[2];
        struct scatterlist *psrc;
 };
@@ -1609,6 +1609,7 @@ static void ahash_done(struct device *dev,
        if (!req_ctx->last && req_ctx->to_hash_later) {
                /* Position any partial block for next update/final/finup */
                memcpy(req_ctx->buf, req_ctx->bufnext, req_ctx->to_hash_later);
+               req_ctx->nbuf = req_ctx->to_hash_later;
        }
        common_nonsnoop_hash_unmap(dev, edesc, areq);
 
@@ -1724,7 +1725,7 @@ static int ahash_init(struct ahash_request *areq)
        struct talitos_ahash_req_ctx *req_ctx = ahash_request_ctx(areq);
 
        /* Initialize the context */
-       req_ctx->count = 0;
+       req_ctx->nbuf = 0;
        req_ctx->first = 1; /* first indicates h/w must init its context */
        req_ctx->swinit = 0; /* assume h/w init of context */
        req_ctx->hw_context_size =
@@ -1772,52 +1773,54 @@ static int ahash_process_req(struct ahash_request *areq, unsigned int nbytes)
                        crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
        unsigned int nbytes_to_hash;
        unsigned int to_hash_later;
-       unsigned int index;
+       unsigned int nsg;
        int chained;
 
-       index = req_ctx->count & (blocksize - 1);
-       req_ctx->count += nbytes;
-
-       if (!req_ctx->last && (index + nbytes) < blocksize) {
-               /* Buffer the partial block */
+       if (!req_ctx->last && (nbytes + req_ctx->nbuf <= blocksize)) {
+               /* Buffer up to one whole block */
                sg_copy_to_buffer(areq->src,
                                  sg_count(areq->src, nbytes, &chained),
-                                 req_ctx->buf + index, nbytes);
+                                 req_ctx->buf + req_ctx->nbuf, nbytes);
+               req_ctx->nbuf += nbytes;
                return 0;
        }
 
-       if (index) {
-               /* partial block from previous update; chain it in. */
-               sg_init_table(req_ctx->bufsl, (nbytes) ? 2 : 1);
-               sg_set_buf(req_ctx->bufsl, req_ctx->buf, index);
-               if (nbytes)
-                       scatterwalk_sg_chain(req_ctx->bufsl, 2,
-                                            areq->src);
+       /* At least (blocksize + 1) bytes are available to hash */
+       nbytes_to_hash = nbytes + req_ctx->nbuf;
+       to_hash_later = nbytes_to_hash & (blocksize - 1);
+
+       if (req_ctx->last)
+               to_hash_later = 0;
+       else if (to_hash_later)
+               /* There is a partial block. Hash the full block(s) now */
+               nbytes_to_hash -= to_hash_later;
+       else {
+               /* Keep one block buffered */
+               nbytes_to_hash -= blocksize;
+               to_hash_later = blocksize;
+       }
+
+       /* Chain in any previously buffered data */
+       if (req_ctx->nbuf) {
+               nsg = (req_ctx->nbuf < nbytes_to_hash) ? 2 : 1;
+               sg_init_table(req_ctx->bufsl, nsg);
+               sg_set_buf(req_ctx->bufsl, req_ctx->buf, req_ctx->nbuf);
+               if (nsg > 1)
+                       scatterwalk_sg_chain(req_ctx->bufsl, 2, areq->src);
                req_ctx->psrc = req_ctx->bufsl;
-       } else {
+       } else
                req_ctx->psrc = areq->src;
+
+       if (to_hash_later) {
+               int nents = sg_count(areq->src, nbytes, &chained);
+               sg_copy_end_to_buffer(areq->src, nents,
+                                     req_ctx->bufnext,
+                                     to_hash_later,
+                                     nbytes - to_hash_later);
        }
-       nbytes_to_hash =  index + nbytes;
-       if (!req_ctx->last) {
-               to_hash_later = (nbytes_to_hash & (blocksize - 1));
-               if (to_hash_later) {
-                       int nents;
-                       /* Must copy to_hash_later bytes from the end
-                        * to bufnext (a partial block) for later.
-                        */
-                       nents = sg_count(areq->src, nbytes, &chained);
-                       sg_copy_end_to_buffer(areq->src, nents,
-                                             req_ctx->bufnext,
-                                             to_hash_later,
-                                             nbytes - to_hash_later);
-
-                       /* Adjust count for what will be hashed now */
-                       nbytes_to_hash -= to_hash_later;
-               }
-               req_ctx->to_hash_later = to_hash_later;
-       }
+       req_ctx->to_hash_later = to_hash_later;
 
-       /* allocate extended descriptor */
+       /* Allocate extended descriptor */
        edesc = ahash_edesc_alloc(areq, nbytes_to_hash);
        if (IS_ERR(edesc))
                return PTR_ERR(edesc);