Message-ID: <e2dd4a02-12cb-de5e-4b64-9d6a4a1ad316@linux.microsoft.com>
Date:   Thu, 2 Feb 2023 17:36:05 -0800
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Subject: Re: [PATCH v2 -next] crypto: aspeed: fix type warnings
To:     Neal Liu <neal_liu@aspeedtech.com>, Joel Stanley <joel@jms.id.au>,
        Andrew Jeffery <andrew@aj.id.au>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S . Miller" <davem@davemloft.net>
Cc:     linux-crypto@vger.kernel.org, linux-aspeed@lists.ozlabs.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20230202070345.191514-1-neal_liu@aspeedtech.com>
Content-Language: en-US
From:   Dhananjay Phadke <dphadke@linux.microsoft.com>
In-Reply-To: <20230202070345.191514-1-neal_liu@aspeedtech.com>
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On 2/1/2023 11:03 PM, Neal Liu wrote:
> This patch fixes following warnings:
> 
> 1. sparse: incorrect type in assignment (different base types)
> Fix: change to __le32 type.
> 2. sparse: cast removes address space '__iomem' of expression
> Fix: use readb to avoid dereferencing the memory.
> 
> Signed-off-by: Neal Liu <neal_liu@aspeedtech.com>
> ---
> Change since v1: keep iomem marker to remain its purpose.
> 
>   drivers/crypto/aspeed/aspeed-acry.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/crypto/aspeed/aspeed-acry.c b/drivers/crypto/aspeed/aspeed-acry.c
> index 164c524015f0..f2429e699d14 100644
> --- a/drivers/crypto/aspeed/aspeed-acry.c
> +++ b/drivers/crypto/aspeed/aspeed-acry.c
> @@ -252,7 +252,7 @@ static int aspeed_acry_rsa_ctx_copy(struct aspeed_acry_dev *acry_dev, void *buf,
>   				    enum aspeed_rsa_key_mode mode)
>   {
>   	const u8 *src = xbuf;
> -	u32 *dw_buf = (u32 *)buf;
> +	__le32 *dw_buf = (__le32 *)buf;

All callers are passing acry_dev->buf_addr as buf, can just change that 
type to __le32 * and deref here directly?

>   	int nbits, ndw;
>   	int i, j, idx;
>   	u32 data = 0;
> @@ -302,7 +302,7 @@ static int aspeed_acry_rsa_ctx_copy(struct aspeed_acry_dev *acry_dev, void *buf,
>   static int aspeed_acry_rsa_transfer(struct aspeed_acry_dev *acry_dev)
>   {
>   	struct akcipher_request *req = acry_dev->req;
> -	u8 *sram_buffer = (u8 *)acry_dev->acry_sram;
> +	u8 __iomem *sram_buffer = (u8 __iomem *)acry_dev->acry_sram;

u8 cast seems unnecessary, readb takes (void *) and using "+ data_idx"
offset below anyway.


>   	struct scatterlist *out_sg = req->dst;
>   	static u8 dram_buffer[ASPEED_ACRY_SRAM_MAX_LEN];
>   	int leading_zero = 1;
> @@ -321,11 +321,11 @@ static int aspeed_acry_rsa_transfer(struct aspeed_acry_dev *acry_dev)
>   
>   	for (j = ASPEED_ACRY_SRAM_MAX_LEN - 1; j >= 0; j--) {
>   		data_idx = acry_dev->data_byte_mapping[j];
> -		if (sram_buffer[data_idx] == 0 && leading_zero) {
> +		if (readb(sram_buffer + data_idx) == 0 && leading_zero) {
>   			result_nbytes--;
>   		} else {
>   			leading_zero = 0;
> -			dram_buffer[i] = sram_buffer[data_idx];
> +			dram_buffer[i] = readb(sram_buffer + data_idx);
>   			i++;
>   		}
>   	}