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

From: Sascha Hauer <s.hauer@pengutronix.de>
To: Pankaj Gupta <pankaj.gupta@nxp.com>
Cc: Jonathan Corbet <corbet@lwn.net>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, imx@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 4/5] firmware: imx: add driver for NXP EdgeLock Enclave
Date: Fri, 24 May 2024 12:47:17 +0200	[thread overview]
Message-ID: <ZlBwNbkFV1fcnPKE@pengutronix.de> (raw)
In-Reply-To: <20240523-imx-se-if-v2-4-5a6fd189a539@nxp.com>

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(+)
> 
> +static int imx_fetch_se_soc_info(struct device *dev)
> +{
> +	struct se_if_priv *priv = dev_get_drvdata(dev);
> +	struct imx_se_node_info_list *info_list;
> +	const struct imx_se_node_info *info;
> +	struct soc_device_attribute *attr;
> +	struct soc_device *sdev;
> +	u64 serial_num;
> +	u16 soc_rev;
> +	int err = 0;
> +
> +	info = priv->info;
> +	info_list = (struct imx_se_node_info_list *)
> +				device_get_match_data(dev);
> +
> +	/* This function should be called once.
> +	 * Check if the soc_rev is zero to continue.
> +	 */
> +	if (priv->soc_rev)
> +		return err;
> +
> +	err = info->se_fetch_soc_info(dev, &soc_rev, &serial_num);
> +	if (err < 0) {
> +		dev_err(dev, "Failed to fetch SoC Info.");
> +		return err;
> +	}

This is called unconditionally but is not set for i.MX93. You should
either set it for i.MX93 or check it before calling it.

Sascha

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