Re: [PATCH v4 10/20] drivers: crypto: meson: avoid kzalloc in engine thread

[neil . armstrong]

On 12/02/2024 14:50, Alexey Romanov wrote:
> It makes no sense to allocate memory via kzalloc, we
> can use static buffer, speedup data processing and
> don't think about kfree() calls.
>
> Signed-off-by: Alexey Romanov <avromanov@xxxxxxxxxxxxxxxxx>
> ---
>   drivers/crypto/amlogic/amlogic-gxl-cipher.c | 26 ++++++++-------------
>   drivers/crypto/amlogic/amlogic-gxl.h        |  6 ++---
>   2 files changed, 13 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/crypto/amlogic/amlogic-gxl-cipher.c b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
> index c1b3569a614a..3f42b2cc568d 100644
> --- a/drivers/crypto/amlogic/amlogic-gxl-cipher.c
> +++ b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
> @@ -91,7 +91,6 @@ struct cipher_ctx {
>   	struct skcipher_request *areq;
>   	struct scatterlist *src_sg;
>   	struct scatterlist *dst_sg;
> -	void *bkeyiv;
>   
>   	unsigned int src_offset;
>   	unsigned int dst_offset;
> @@ -156,8 +155,7 @@ static void meson_setup_keyiv_descs(struct cipher_ctx *ctx)
>   		return;
>   
>   	if (blockmode == DESC_OPMODE_CBC) {
> -		memcpy(ctx->bkeyiv + AES_MAX_KEY_SIZE, ctx->areq->iv, ivsize);
> -		ctx->keyiv.len = AES_MAX_KEY_SIZE + ivsize;
> +		memcpy(op->keyiv + AES_MAX_KEY_SIZE, ctx->areq->iv, ivsize);
>   		dma_sync_single_for_device(mc->dev, ctx->keyiv.addr,
>   					   ctx->keyiv.len, DMA_TO_DEVICE);
>   	}
> @@ -304,6 +302,7 @@ static int meson_cipher(struct skcipher_request *areq)
>   		.dst_sg = areq->dst,
>   		.cryptlen = areq->cryptlen,
>   	};
> +	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
>   	int err;
>   
>   	dev_dbg(mc->dev, "%s %s %u %x IV(%u) key=%u ctx.flow=%d\n", __func__,
> @@ -319,16 +318,16 @@ static int meson_cipher(struct skcipher_request *areq)
>   	mc->chanlist[rctx->flow].stat_req++;
>   #endif
>   
> -	ctx.bkeyiv = kzalloc(48, GFP_KERNEL | GFP_DMA);
> -	if (!ctx.bkeyiv)
> -		return -ENOMEM;
> -
> -	memcpy(ctx.bkeyiv, op->key, op->keylen);
>   	ctx.keyiv.len = op->keylen;
>   	if (ctx.keyiv.len == AES_KEYSIZE_192)
>   		ctx.keyiv.len = AES_MAX_KEY_SIZE;
>   
> -	ctx.keyiv.addr = dma_map_single(mc->dev, ctx.bkeyiv, ctx.keyiv.len,
> +	if (algt->blockmode == DESC_OPMODE_CBC) {
> +		memcpy(op->keyiv + AES_MAX_KEY_SIZE, areq->iv, ivsize);
> +		ctx.keyiv.len = AES_MAX_KEY_SIZE + ivsize;
> +	}
> +
> +	ctx.keyiv.addr = dma_map_single(mc->dev, op->keyiv, ctx.keyiv.len,
>   				  DMA_TO_DEVICE);
>   	err = dma_mapping_error(mc->dev, ctx.keyiv.addr);
>   	if (err) {
> @@ -366,8 +365,6 @@ static int meson_cipher(struct skcipher_request *areq)
>   	meson_unmap_scatterlist(areq, mc);
>   
>   theend:
> -	kfree_sensitive(ctx.bkeyiv);
> -
>   	return err;
>   }
>   
> @@ -450,7 +447,6 @@ static void meson_cipher_exit(struct crypto_tfm *tfm)
>   {
>   	struct meson_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
>   
> -	kfree_sensitive(op->key);
>   	crypto_free_skcipher(op->fallback_tfm);
>   }
>   
> @@ -474,11 +470,9 @@ static int meson_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
>   		dev_dbg(mc->dev, "ERROR: Invalid keylen %u\n", keylen);
>   		return -EINVAL;
>   	}
> -	kfree_sensitive(op->key);
> +
> +	memcpy(op->keyiv, key, keylen);
>   	op->keylen = keylen;
> -	op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
> -	if (!op->key)
> -		return -ENOMEM;
>   
>   	return crypto_skcipher_setkey(op->fallback_tfm, key, keylen);
>   }
> diff --git a/drivers/crypto/amlogic/amlogic-gxl.h b/drivers/crypto/amlogic/amlogic-gxl.h
> index eb2f8cd72b65..e1453dd2e9f4 100644
> --- a/drivers/crypto/amlogic/amlogic-gxl.h
> +++ b/drivers/crypto/amlogic/amlogic-gxl.h
> @@ -129,15 +129,15 @@ struct meson_cipher_req_ctx {
>   
>   /*
>    * struct meson_cipher_tfm_ctx - context for a skcipher TFM
> - * @key:		pointer to key data
> + * @keyiv:		key data
>    * @keylen:		len of the key
>    * @keymode:		The keymode(type and size of key) associated with this TFM
>    * @mc:			pointer to the private data of driver handling this TFM
>    * @fallback_tfm:	pointer to the fallback TFM
>    */
>   struct meson_cipher_tfm_ctx {
> -	u32 *key;
> -	u32 keylen;
> +	u8 keyiv[AES_MAX_KEY_SIZE + AES_BLOCK_SIZE] ____cacheline_aligned;
> +	u32 keylen ____cacheline_aligned;
>   	u32 keymode;
>   	struct meson_dev *mc;
>   	struct crypto_skcipher *fallback_tfm;

Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>