Re: [RFC PATCH V2] Crypto: rockchip/crypto - add hash support for crypto engine in rk3288

[LABBE Corentin <clabbe.montjoie@gmail.com>]

Hello

I have some comments below.

On Wed, Dec 09, 2015 at 06:16:42PM +0800, Zain Wang wrote:
> Add md5 sha1 sha256 support for crypto engine in rk3288.
> This patch can't support multiple updatings because of limited of IC,
> as result, it can't support import and export too.
> 
> Signed-off-by: Zain Wang <zain.wang@rock-chips.com>
> ---
> 
> Changes in V2:
> - add some comments to code.
> - fix some issues about zero message process.
> 
>  drivers/crypto/rockchip/Makefile                   |   1 +
>  drivers/crypto/rockchip/rk3288_crypto.c            |  33 +-
>  drivers/crypto/rockchip/rk3288_crypto.h            |  50 ++-
>  drivers/crypto/rockchip/rk3288_crypto_ablkcipher.c |  20 +-
>  drivers/crypto/rockchip/rk3288_crypto_ahash.c      | 383 +++++++++++++++++++++
>  5 files changed, 469 insertions(+), 18 deletions(-)
>  create mode 100644 drivers/crypto/rockchip/rk3288_crypto_ahash.c
> 
> @@ -194,6 +221,12 @@ struct rk_crypto_info {
>  			 struct scatterlist *sg_dst);
>  	void (*unload_data)(struct rk_crypto_info *dev);
>  };
> +/* the private variable of hash */
> +struct rk_ahash_ctx {
> +	struct rk_crypto_info		*dev;
> +	int				FLAG_FINUP;

Why this variable is uppercase ?

> +
> +
> +static void zero_message_process(struct ahash_request *req)
> +{
> +	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
> +	int rk_digest_size;
> +
> +	rk_digest_size = crypto_ahash_digestsize(tfm);
> +
> +	if (rk_digest_size == SHA1_DIGEST_SIZE)
> +		memcpy(req->result, sha1_zero_message_hash, rk_digest_size);
> +	else if (rk_digest_size == SHA256_DIGEST_SIZE)
> +		memcpy(req->result, sha256_zero_message_hash, rk_digest_size);
> +	else if (rk_digest_size == MD5_DIGEST_SIZE)
> +		memcpy(req->result, md5_zero_message_hash, rk_digest_size);

A switch would be more pretty, and eventualy handle invalid rk_digest_size value.

> +}
> +
> +static void rk_ahash_crypto_complete(struct rk_crypto_info *dev, int err)
> +{
> +	if (dev->ahash_req->base.complete)
> +		dev->ahash_req->base.complete(&dev->ahash_req->base, err);
> +}
> +
> +static void rk_ahash_hw_init(struct rk_crypto_info *dev)
> +{
> +	int reg_status = 0;
> +
> +	reg_status = CRYPTO_READ(dev, RK_CRYPTO_CTRL) |
> +		     RK_CRYPTO_HASH_FLUSH | _SBF(0xffff, 16);
> +	CRYPTO_WRITE(dev, RK_CRYPTO_CTRL, reg_status);
> +
> +	reg_status = CRYPTO_READ(dev, RK_CRYPTO_CTRL);
> +	reg_status &= (~RK_CRYPTO_HASH_FLUSH);
> +	reg_status |= _SBF(0xffff, 16);
> +	CRYPTO_WRITE(dev, RK_CRYPTO_CTRL, reg_status);
> +
> +	memset_io(dev->reg + RK_CRYPTO_HASH_DOUT_0, 0, 32);
> +}
> +
> +static void rk_ahash_reg_init(struct rk_crypto_info *dev)
> +{
> +	rk_ahash_hw_init(dev);
> +
> +	CRYPTO_WRITE(dev, RK_CRYPTO_INTENA, RK_CRYPTO_HRDMA_ERR_ENA |
> +					    RK_CRYPTO_HRDMA_DONE_ENA);
> +
> +	CRYPTO_WRITE(dev, RK_CRYPTO_INTSTS, RK_CRYPTO_HRDMA_ERR_INT |
> +					    RK_CRYPTO_HRDMA_DONE_INT);
> +
> +	CRYPTO_WRITE(dev, RK_CRYPTO_HASH_CTRL, dev->mode |
> +					       RK_CRYPTO_HASH_SWAP_DO);
> +
> +	CRYPTO_WRITE(dev, RK_CRYPTO_CONF, RK_CRYPTO_BYTESWAP_HRFIFO |
> +					  RK_CRYPTO_BYTESWAP_BRFIFO |
> +					  RK_CRYPTO_BYTESWAP_BTFIFO);
> +}
> +
> +static int rk_ahash_init(struct ahash_request *req)
> +{
> +	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
> +	struct rk_ahash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
> +	struct rk_crypto_info *dev = NULL;
> +	int rk_digest_size;
> +
> +	dev = tctx->dev;
> +	dev->left_bytes = 0;
> +	dev->aligned = 0;
> +	dev->ahash_req = req;
> +	dev->mode = 0;
> +	dev->align_size = 4;
> +	dev->sg_dst = NULL;
> +
> +	tctx->first_op = 1;
> +
> +	rk_digest_size = crypto_ahash_digestsize(tfm);
> +	if (!rk_digest_size)
> +		dev_err(dev->dev, "can't get digestsize\n");

You print an error but continue, it is strange.

> +	if (rk_digest_size == SHA1_DIGEST_SIZE)
> +		dev->mode = RK_CRYPTO_HASH_SHA1;
> +	else if (rk_digest_size == SHA256_DIGEST_SIZE)
> +		dev->mode = RK_CRYPTO_HASH_SHA256;
> +	else if (rk_digest_size == MD5_DIGEST_SIZE)
> +		dev->mode = RK_CRYPTO_HASH_MD5;

A switch will be better here.

Regards