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crypto: ccree - remove special handling of chained sg
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We were handling chained scattergather lists with specialized code
needlessly as the regular sg APIs handle them just fine. The code
handling this also had an (unused) code path with a use-before-init
error, flagged by Coverity.

Remove all special handling of chained sg and leave their handling
to the regular sg APIs.

Signed-off-by: Gilad Ben-Yossef <[email protected]>
Cc: [email protected] # v4.19+
Signed-off-by: Herbert Xu <[email protected]>
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gby authored and herbertx committed Apr 25, 2019
1 parent 151ded7 commit c4b22bf
Showing 1 changed file with 22 additions and 76 deletions.
98 changes: 22 additions & 76 deletions drivers/crypto/ccree/cc_buffer_mgr.c
Original file line number Diff line number Diff line change
Expand Up @@ -83,24 +83,17 @@ static void cc_copy_mac(struct device *dev, struct aead_request *req,
*/
static unsigned int cc_get_sgl_nents(struct device *dev,
struct scatterlist *sg_list,
unsigned int nbytes, u32 *lbytes,
bool *is_chained)
unsigned int nbytes, u32 *lbytes)
{
unsigned int nents = 0;

while (nbytes && sg_list) {
if (sg_list->length) {
nents++;
/* get the number of bytes in the last entry */
*lbytes = nbytes;
nbytes -= (sg_list->length > nbytes) ?
nbytes : sg_list->length;
sg_list = sg_next(sg_list);
} else {
sg_list = (struct scatterlist *)sg_page(sg_list);
if (is_chained)
*is_chained = true;
}
nents++;
/* get the number of bytes in the last entry */
*lbytes = nbytes;
nbytes -= (sg_list->length > nbytes) ?
nbytes : sg_list->length;
sg_list = sg_next(sg_list);
}
dev_dbg(dev, "nents %d last bytes %d\n", nents, *lbytes);
return nents;
Expand Down Expand Up @@ -142,7 +135,7 @@ void cc_copy_sg_portion(struct device *dev, u8 *dest, struct scatterlist *sg,
{
u32 nents, lbytes;

nents = cc_get_sgl_nents(dev, sg, end, &lbytes, NULL);
nents = cc_get_sgl_nents(dev, sg, end, &lbytes);
sg_copy_buffer(sg, nents, (void *)dest, (end - to_skip + 1), to_skip,
(direct == CC_SG_TO_BUF));
}
Expand Down Expand Up @@ -314,40 +307,10 @@ static void cc_add_sg_entry(struct device *dev, struct buffer_array *sgl_data,
sgl_data->num_of_buffers++;
}

static int cc_dma_map_sg(struct device *dev, struct scatterlist *sg, u32 nents,
enum dma_data_direction direction)
{
u32 i, j;
struct scatterlist *l_sg = sg;

for (i = 0; i < nents; i++) {
if (!l_sg)
break;
if (dma_map_sg(dev, l_sg, 1, direction) != 1) {
dev_err(dev, "dma_map_page() sg buffer failed\n");
goto err;
}
l_sg = sg_next(l_sg);
}
return nents;

err:
/* Restore mapped parts */
for (j = 0; j < i; j++) {
if (!sg)
break;
dma_unmap_sg(dev, sg, 1, direction);
sg = sg_next(sg);
}
return 0;
}

static int cc_map_sg(struct device *dev, struct scatterlist *sg,
unsigned int nbytes, int direction, u32 *nents,
u32 max_sg_nents, u32 *lbytes, u32 *mapped_nents)
{
bool is_chained = false;

if (sg_is_last(sg)) {
/* One entry only case -set to DLLI */
if (dma_map_sg(dev, sg, 1, direction) != 1) {
Expand All @@ -361,35 +324,21 @@ static int cc_map_sg(struct device *dev, struct scatterlist *sg,
*nents = 1;
*mapped_nents = 1;
} else { /*sg_is_last*/
*nents = cc_get_sgl_nents(dev, sg, nbytes, lbytes,
&is_chained);
*nents = cc_get_sgl_nents(dev, sg, nbytes, lbytes);
if (*nents > max_sg_nents) {
*nents = 0;
dev_err(dev, "Too many fragments. current %d max %d\n",
*nents, max_sg_nents);
return -ENOMEM;
}
if (!is_chained) {
/* In case of mmu the number of mapped nents might
* be changed from the original sgl nents
*/
*mapped_nents = dma_map_sg(dev, sg, *nents, direction);
if (*mapped_nents == 0) {
*nents = 0;
dev_err(dev, "dma_map_sg() sg buffer failed\n");
return -ENOMEM;
}
} else {
/*In this case the driver maps entry by entry so it
* must have the same nents before and after map
*/
*mapped_nents = cc_dma_map_sg(dev, sg, *nents,
direction);
if (*mapped_nents != *nents) {
*nents = *mapped_nents;
dev_err(dev, "dma_map_sg() sg buffer failed\n");
return -ENOMEM;
}
/* In case of mmu the number of mapped nents might
* be changed from the original sgl nents
*/
*mapped_nents = dma_map_sg(dev, sg, *nents, direction);
if (*mapped_nents == 0) {
*nents = 0;
dev_err(dev, "dma_map_sg() sg buffer failed\n");
return -ENOMEM;
}
}

Expand Down Expand Up @@ -571,7 +520,6 @@ void cc_unmap_aead_request(struct device *dev, struct aead_request *req)
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
struct cc_drvdata *drvdata = dev_get_drvdata(dev);
u32 dummy;
bool chained;
u32 size_to_unmap = 0;

if (areq_ctx->mac_buf_dma_addr) {
Expand Down Expand Up @@ -636,15 +584,14 @@ void cc_unmap_aead_request(struct device *dev, struct aead_request *req)
size_to_unmap += crypto_aead_ivsize(tfm);

dma_unmap_sg(dev, req->src,
cc_get_sgl_nents(dev, req->src, size_to_unmap,
&dummy, &chained),
cc_get_sgl_nents(dev, req->src, size_to_unmap, &dummy),
DMA_BIDIRECTIONAL);
if (req->src != req->dst) {
dev_dbg(dev, "Unmapping dst sgl: req->dst=%pK\n",
sg_virt(req->dst));
dma_unmap_sg(dev, req->dst,
cc_get_sgl_nents(dev, req->dst, size_to_unmap,
&dummy, &chained),
&dummy),
DMA_BIDIRECTIONAL);
}
if (drvdata->coherent &&
Expand Down Expand Up @@ -1022,7 +969,6 @@ static int cc_aead_chain_data(struct cc_drvdata *drvdata,
unsigned int size_for_map = req->assoclen + req->cryptlen;
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
u32 sg_index = 0;
bool chained = false;
bool is_gcm4543 = areq_ctx->is_gcm4543;
u32 size_to_skip = req->assoclen;

Expand All @@ -1043,7 +989,7 @@ static int cc_aead_chain_data(struct cc_drvdata *drvdata,
size_for_map += (direct == DRV_CRYPTO_DIRECTION_ENCRYPT) ?
authsize : 0;
src_mapped_nents = cc_get_sgl_nents(dev, req->src, size_for_map,
&src_last_bytes, &chained);
&src_last_bytes);
sg_index = areq_ctx->src_sgl->length;
//check where the data starts
while (sg_index <= size_to_skip) {
Expand Down Expand Up @@ -1083,7 +1029,7 @@ static int cc_aead_chain_data(struct cc_drvdata *drvdata,
}

dst_mapped_nents = cc_get_sgl_nents(dev, req->dst, size_for_map,
&dst_last_bytes, &chained);
&dst_last_bytes);
sg_index = areq_ctx->dst_sgl->length;
offset = size_to_skip;

Expand Down Expand Up @@ -1484,7 +1430,7 @@ int cc_map_hash_request_update(struct cc_drvdata *drvdata, void *ctx,
dev_dbg(dev, " less than one block: curr_buff=%pK *curr_buff_cnt=0x%X copy_to=%pK\n",
curr_buff, *curr_buff_cnt, &curr_buff[*curr_buff_cnt]);
areq_ctx->in_nents =
cc_get_sgl_nents(dev, src, nbytes, &dummy, NULL);
cc_get_sgl_nents(dev, src, nbytes, &dummy);
sg_copy_to_buffer(src, areq_ctx->in_nents,
&curr_buff[*curr_buff_cnt], nbytes);
*curr_buff_cnt += nbytes;
Expand Down

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