Re: [PATCH v2 4/5] firmware: imx: add driver for NXP EdgeLock Enclave

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, May 23, 2024 at 04:19:35PM +0530, Pankaj Gupta wrote:
> NXP hardware IP(s) for secure-enclaves like Edgelock Enclave(ELE),
> are embedded in the SoC to support the features like HSM, SHE & V2X,
> using message based communication interface.
> 
> The secure enclave FW communicates on a dedicated messaging unit(MU)
> based interface(s) with application core, where kernel is running.
> It exists on specific i.MX processors. e.g. i.MX8ULP, i.MX93.
> 
> This patch adds the driver for communication interface to secure-enclave,
> for exchanging messages with NXP secure enclave HW IP(s) like EdgeLock
> Enclave (ELE) from Kernel-space, used by kernel management layers like
> - DM-Crypt.
> 
> Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
> ---
>  drivers/firmware/imx/Kconfig        |  12 +
>  drivers/firmware/imx/Makefile       |   2 +
>  drivers/firmware/imx/ele_base_msg.c | 286 +++++++++++++++++++
>  drivers/firmware/imx/ele_base_msg.h |  92 +++++++
>  drivers/firmware/imx/ele_common.c   | 239 ++++++++++++++++
>  drivers/firmware/imx/ele_common.h   |  43 +++
>  drivers/firmware/imx/se_ctrl.c      | 531 ++++++++++++++++++++++++++++++++++++
>  drivers/firmware/imx/se_ctrl.h      |  99 +++++++
>  include/linux/firmware/imx/se_api.h |  14 +
>  9 files changed, 1318 insertions(+)

[...]

> 
> +int imx_ele_msg_send(struct se_if_priv *priv, void *tx_msg)
> +{
> +	struct se_msg_hdr *header;
> +	int err;
> +
> +	header = (struct se_msg_hdr *) tx_msg;
> +
> +	if (header->tag == priv->cmd_tag)
> +		lockdep_assert_held(&priv->se_if_cmd_lock);
> +
> +	scoped_guard(mutex, &priv->se_if_lock);

scoped_guard() with an empty block doesn't make much sense. Either use
scope_guard() { /* do something locked */ }; or guard().

Sascha

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