[PATCH] mmc: rpmb: realign frames before passing to MMC driver

[Peng Fan]

On 5/11/2023 11:07 PM, Pavel Löbl wrote:
> MMC driver requires request and response frame buffers to be properly
> aligned for DMA transfers.
> 
> Fix already implemented reallocation for request frame and also add
> realigment for response frame if needed.

Have you met any issues without your patch?

> 
> Signed-off-by: Pavel Löbl <pavel at loebl.cz>
> ---
>   drivers/mmc/rpmb.c | 17 +++++++++++++++--
>   1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/rpmb.c b/drivers/mmc/rpmb.c
> index b68d98573c..e951f4e9bd 100644
> --- a/drivers/mmc/rpmb.c
> +++ b/drivers/mmc/rpmb.c
> @@ -482,13 +482,14 @@ int mmc_rpmb_route_frames(struct mmc *mmc, void *req, unsigned long reqlen,
>   	 */
>   	void *rpmb_data = NULL;
>   	int ret;
> +	void *rsp_aligned = rsp;
>   
>   	if (reqlen % sizeof(struct s_rpmb) || rsplen % sizeof(struct s_rpmb))
>   		return -EINVAL;
>   
>   	if (!IS_ALIGNED((uintptr_t)req, ARCH_DMA_MINALIGN)) {
>   		/* Memory alignment is required by MMC driver */
> -		rpmb_data = malloc(reqlen);
> +		rpmb_data = memalign(ARCH_DMA_MINALIGN, reqlen);

The mmc driver use ALLOC_CACHE_ALIGN_BUFFER, so better align.

Regards,
Peng.

>   		if (!rpmb_data)
>   			return -ENOMEM;
>   
> @@ -496,8 +497,20 @@ int mmc_rpmb_route_frames(struct mmc *mmc, void *req, unsigned long reqlen,
>   		req = rpmb_data;
>   	}
>   
> +	if (!IS_ALIGNED((uintptr_t)rsp_aligned, ARCH_DMA_MINALIGN)) {
> +		rsp_aligned = memalign(ARCH_DMA_MINALIGN, rsplen);
> +		if (!rsp_aligned)
> +			return -ENOMEM;
> +	}
> +
>   	ret = rpmb_route_frames(mmc, req, reqlen / sizeof(struct s_rpmb),
> -				rsp, rsplen / sizeof(struct s_rpmb));
> +				rsp_aligned, rsplen / sizeof(struct s_rpmb));
> +
> +	if (rsp_aligned != rsp) {
> +		memcpy(rsp, rsp_aligned, rsplen);
> +		free(rsp_aligned);
> +	}
> +
>   	free(rpmb_data);
>   	return ret;
>   }