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[2/2] crypto: marvell - Don't break chain for computable last ahash requests

Message ID 1471522334-24839-3-git-send-email-romain.perier@free-electrons.com (mailing list archive)
State Changes Requested
Delegated to: Herbert Xu
Headers show

Commit Message

Romain Perier Aug. 18, 2016, 12:12 p.m. UTC
Currently, the driver breaks chain for all kind of hash requests in order
to don't override intermediate states of partial ahash updates. However,
some final ahash requests can be directly processed by the engine, and
so without intermediate state. This is typically the case for most for
the HMAC requests processed via IPSec.

This commits adds a TDMA descriptor to copy outer results for thise kind
of request into the "result" dma pool, then it allow to chain these
requests at the DMA level. The 'complete' operation is also updated to
retrieve the MAC digest from the right location.

Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
---
 drivers/crypto/marvell/hash.c | 69 +++++++++++++++++++++++++++++++++----------
 1 file changed, 54 insertions(+), 15 deletions(-)

Comments

Boris BREZILLON Aug. 20, 2016, 7:17 a.m. UTC | #1
On Thu, 18 Aug 2016 14:12:14 +0200
Romain Perier <romain.perier@free-electrons.com> wrote:

> Currently, the driver breaks chain for all kind of hash requests in order
> to don't override intermediate states of partial ahash updates. However,
> some final ahash requests can be directly processed by the engine, and
> so without intermediate state. This is typically the case for most for
> the HMAC requests processed via IPSec.
> 
> This commits adds a TDMA descriptor to copy outer results for thise kind
> of request into the "result" dma pool, then it allow to chain these
> requests at the DMA level. The 'complete' operation is also updated to
> retrieve the MAC digest from the right location.
> 
> Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
> ---
>  drivers/crypto/marvell/hash.c | 69 +++++++++++++++++++++++++++++++++----------
>  1 file changed, 54 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c
> index 9f28468..1a91662 100644
> --- a/drivers/crypto/marvell/hash.c
> +++ b/drivers/crypto/marvell/hash.c
> @@ -312,24 +312,48 @@ static void mv_cesa_ahash_complete(struct crypto_async_request *req)
>  	int i;
>  
>  	digsize = crypto_ahash_digestsize(crypto_ahash_reqtfm(ahashreq));
> -	for (i = 0; i < digsize / 4; i++)
> -		creq->state[i] = readl_relaxed(engine->regs + CESA_IVDIG(i));
>  
> -	if (creq->last_req) {
> +	if (mv_cesa_req_get_type(&creq->base) == CESA_DMA_REQ &&
> +	    !(creq->base.chain.last->flags & CESA_TDMA_BREAK_CHAIN)) {
> +		struct mv_cesa_tdma_desc *tdma = NULL;
> +
> +		for (tdma = creq->base.chain.first; tdma; tdma = tdma->next) {
> +			u32 type = tdma->flags & CESA_TDMA_TYPE_MSK;
> +			if (type ==  CESA_TDMA_RESULT)
> +				break;
> +		}
> +
> +		BUG_ON(!tdma);

Let's try to use BUG_ON() only when we can't recover from a failure.
This is not the case here, just print an error message, or even better, 
move this check in ->process() where you can return an error code
(note that this requires changing a bit the way you are handling
errors in mv_cesa_tdma_process()).

> +
>  		/*
> -		 * Hardware's MD5 digest is in little endian format, but
> -		 * SHA in big endian format
> +		 * Result is already in the correct endianess when the SA is
> +		 * used
>  		 */
> -		if (creq->algo_le) {
> -			__le32 *result = (void *)ahashreq->result;
> +		__le32 *data = tdma->data + 0x40;
> +		for (i = 0; i < digsize / 4; i++)
> +			creq->state[i] = cpu_to_le32(data[i]);
>  
> -			for (i = 0; i < digsize / 4; i++)
> -				result[i] = cpu_to_le32(creq->state[i]);
> -		} else {
> -			__be32 *result = (void *)ahashreq->result;
> +		memcpy(ahashreq->result, data, digsize);

Is it safe to do that when you're in big endian (that's not a
rhetorical question, I always have a hard time figuring when endianess
conversion should be done)?

> +	} else {
> +		for (i = 0; i < digsize / 4; i++)
> +			creq->state[i] = readl_relaxed(engine->regs +
> +						       CESA_IVDIG(i));
> +		if (creq->last_req) {
> +			/*
> +			* Hardware's MD5 digest is in little endian format, but
> +			* SHA in big endian format
> +			*/
> +			if (creq->algo_le) {
> +				__le32 *result = (void *)ahashreq->result;
> +
> +				for (i = 0; i < digsize / 4; i++)
> +					result[i] = cpu_to_le32(creq->state[i]);
> +			} else {
> +				__be32 *result = (void *)ahashreq->result;
>  
> -			for (i = 0; i < digsize / 4; i++)
> -				result[i] = cpu_to_be32(creq->state[i]);
> +				for (i = 0; i < digsize / 4; i++)
> +					result[i] = cpu_to_be32(creq->state[i]);
> +			}
>  		}
>  	}
>  
> @@ -504,6 +528,11 @@ mv_cesa_ahash_dma_last_req(struct mv_cesa_tdma_chain *chain,
>  						CESA_SA_DESC_CFG_LAST_FRAG,
>  				      CESA_SA_DESC_CFG_FRAG_MSK);
>  
> +		ret = mv_cesa_dma_add_result_op(chain,
> +						CESA_SA_MAC_IIV_SRAM_OFFSET, 96,
> +						CESA_TDMA_SRC_IN_SRAM, flags);
> +		if (ret)
> +			return ERR_PTR(-ENOMEM);
>  		return op;
>  	}
>  
> @@ -564,6 +593,7 @@ static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
>  	struct mv_cesa_op_ctx *op = NULL;
>  	unsigned int frag_len;
>  	int ret;
> +	u32 type;

How about naming this variable break_chain? This would be clearer IMO.

	bool break_chain = false;

>  
>  	basereq->chain.first = NULL;
>  	basereq->chain.last = NULL;
> @@ -635,6 +665,8 @@ static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
>  		goto err_free_tdma;
>  	}
>  
> +	type = basereq->chain.last->flags & CESA_TDMA_TYPE_MSK;
> +

	if (basereq->chain.last->flags & CESA_TDMA_TYPE_MSK)
		break_chain = true;

>  	if (op) {
>  		/* Add dummy desc to wait for crypto operation end */
>  		ret = mv_cesa_dma_add_dummy_end(&basereq->chain, flags);
> @@ -648,8 +680,15 @@ static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
>  	else
>  		creq->cache_ptr = 0;
>  
> -	basereq->chain.last->flags |= (CESA_TDMA_END_OF_REQ |
> -				       CESA_TDMA_BREAK_CHAIN);
> +	basereq->chain.last->flags |= CESA_TDMA_END_OF_REQ;
> +	/*
> +	 * If results are copied via DMA, this means that this
> +	 * request can be directly processed by the engine,
> +	 * without partial updates. So we can chain it at the
> +	 * DMA level with other requests.
> +	 */

Move the comment where you're assigning break_chain to true.

> +	if (type != CESA_TDMA_RESULT)

	if (break_chain)

> +		basereq->chain.last->flags |= CESA_TDMA_BREAK_CHAIN;
>  
>  	return 0;
>  

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diff mbox

Patch

diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c
index 9f28468..1a91662 100644
--- a/drivers/crypto/marvell/hash.c
+++ b/drivers/crypto/marvell/hash.c
@@ -312,24 +312,48 @@  static void mv_cesa_ahash_complete(struct crypto_async_request *req)
 	int i;
 
 	digsize = crypto_ahash_digestsize(crypto_ahash_reqtfm(ahashreq));
-	for (i = 0; i < digsize / 4; i++)
-		creq->state[i] = readl_relaxed(engine->regs + CESA_IVDIG(i));
 
-	if (creq->last_req) {
+	if (mv_cesa_req_get_type(&creq->base) == CESA_DMA_REQ &&
+	    !(creq->base.chain.last->flags & CESA_TDMA_BREAK_CHAIN)) {
+		struct mv_cesa_tdma_desc *tdma = NULL;
+
+		for (tdma = creq->base.chain.first; tdma; tdma = tdma->next) {
+			u32 type = tdma->flags & CESA_TDMA_TYPE_MSK;
+			if (type ==  CESA_TDMA_RESULT)
+				break;
+		}
+
+		BUG_ON(!tdma);
+
 		/*
-		 * Hardware's MD5 digest is in little endian format, but
-		 * SHA in big endian format
+		 * Result is already in the correct endianess when the SA is
+		 * used
 		 */
-		if (creq->algo_le) {
-			__le32 *result = (void *)ahashreq->result;
+		__le32 *data = tdma->data + 0x40;
+		for (i = 0; i < digsize / 4; i++)
+			creq->state[i] = cpu_to_le32(data[i]);
 
-			for (i = 0; i < digsize / 4; i++)
-				result[i] = cpu_to_le32(creq->state[i]);
-		} else {
-			__be32 *result = (void *)ahashreq->result;
+		memcpy(ahashreq->result, data, digsize);
+	} else {
+		for (i = 0; i < digsize / 4; i++)
+			creq->state[i] = readl_relaxed(engine->regs +
+						       CESA_IVDIG(i));
+		if (creq->last_req) {
+			/*
+			* Hardware's MD5 digest is in little endian format, but
+			* SHA in big endian format
+			*/
+			if (creq->algo_le) {
+				__le32 *result = (void *)ahashreq->result;
+
+				for (i = 0; i < digsize / 4; i++)
+					result[i] = cpu_to_le32(creq->state[i]);
+			} else {
+				__be32 *result = (void *)ahashreq->result;
 
-			for (i = 0; i < digsize / 4; i++)
-				result[i] = cpu_to_be32(creq->state[i]);
+				for (i = 0; i < digsize / 4; i++)
+					result[i] = cpu_to_be32(creq->state[i]);
+			}
 		}
 	}
 
@@ -504,6 +528,11 @@  mv_cesa_ahash_dma_last_req(struct mv_cesa_tdma_chain *chain,
 						CESA_SA_DESC_CFG_LAST_FRAG,
 				      CESA_SA_DESC_CFG_FRAG_MSK);
 
+		ret = mv_cesa_dma_add_result_op(chain,
+						CESA_SA_MAC_IIV_SRAM_OFFSET, 96,
+						CESA_TDMA_SRC_IN_SRAM, flags);
+		if (ret)
+			return ERR_PTR(-ENOMEM);
 		return op;
 	}
 
@@ -564,6 +593,7 @@  static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
 	struct mv_cesa_op_ctx *op = NULL;
 	unsigned int frag_len;
 	int ret;
+	u32 type;
 
 	basereq->chain.first = NULL;
 	basereq->chain.last = NULL;
@@ -635,6 +665,8 @@  static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
 		goto err_free_tdma;
 	}
 
+	type = basereq->chain.last->flags & CESA_TDMA_TYPE_MSK;
+
 	if (op) {
 		/* Add dummy desc to wait for crypto operation end */
 		ret = mv_cesa_dma_add_dummy_end(&basereq->chain, flags);
@@ -648,8 +680,15 @@  static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
 	else
 		creq->cache_ptr = 0;
 
-	basereq->chain.last->flags |= (CESA_TDMA_END_OF_REQ |
-				       CESA_TDMA_BREAK_CHAIN);
+	basereq->chain.last->flags |= CESA_TDMA_END_OF_REQ;
+	/*
+	 * If results are copied via DMA, this means that this
+	 * request can be directly processed by the engine,
+	 * without partial updates. So we can chain it at the
+	 * DMA level with other requests.
+	 */
+	if (type != CESA_TDMA_RESULT)
+		basereq->chain.last->flags |= CESA_TDMA_BREAK_CHAIN;
 
 	return 0;