linux-kernel - Re: [PATCH v3 2/4] soc: amlogic: meson-gx-socinfo-sm: Add Amlogic secure-monitor SoC Information driver

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Message-ID: <111346d3-8357-4ca3-9249-a43ebc225fcb@linaro.org>
Date: Thu, 14 Mar 2024 08:11:57 +0100
From: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To: Viacheslav Bocharov <adeep@...ina.in>,
 Neil Armstrong <neil.armstrong@...aro.org>,
 Kevin Hilman <khilman@...libre.com>, Jerome Brunet <jbrunet@...libre.com>,
 Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
 linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
 linux-amlogic@...ts.infradead.org
Cc: Rob Herring <robh+dt@...nel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>
Subject: Re: [PATCH v3 2/4] soc: amlogic: meson-gx-socinfo-sm: Add Amlogic
 secure-monitor SoC Information driver

On 14/03/2024 07:59, Viacheslav Bocharov wrote:
> Amlogic SoCs have a SoC information secure-monitor call for SoC type,
> package type, revision information and chipid.
> This patchs adds support for secure-monitor call decoding and exposing
> with the SoC bus infrastructure in addition to the previous SoC
> Information driver.
> 
> Signed-off-by: Viacheslav Bocharov <adeep@...ina.in>
> ---
>  drivers/soc/amlogic/Kconfig               |  10 ++
>  drivers/soc/amlogic/Makefile              |   1 +
>  drivers/soc/amlogic/meson-gx-socinfo-sm.c | 192 ++++++++++++++++++++++
>  3 files changed, 203 insertions(+)
>  create mode 100644 drivers/soc/amlogic/meson-gx-socinfo-sm.c
> 
> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
> index d08e398bdad4..82fc77ca3b4b 100644
> --- a/drivers/soc/amlogic/Kconfig
> +++ b/drivers/soc/amlogic/Kconfig
> @@ -26,6 +26,16 @@ config MESON_GX_SOCINFO
>  	  Say yes to support decoding of Amlogic Meson GX SoC family
>  	  information about the type, package and version.
>  
> +config MESON_GX_SOCINFO_SM
> +	bool "Amlogic Meson GX SoC Information driver via Secure Monitor"
> +	depends on (ARM64 && ARCH_MESON || COMPILE_TEST) && MESON_SM=y
> +	default ARCH_MESON && MESON_SM
> +	select SOC_BUS
> +	help
> +	  Say yes to support decoding of Amlogic Meson GX SoC family
> +	  information about the type, package and version via secure
> +	  monitor call.
> +

I wonder, why do you need socinfo driver per each SoC? Usually it is one
or two per entire arch.

> +
> +static int meson_gx_socinfo_sm_probe(struct platform_device *pdev)
> +{
> +	struct soc_device_attribute *soc_dev_attr;
> +	struct soc_device *soc_dev;
> +	struct device_node *sm_np;
> +	struct meson_sm_firmware *fw;
> +	struct regmap *regmap;
> +	union meson_cpu_id socinfo;
> +	struct device *dev;
> +	int ret;
> +
> +	/* check if chip-id is available */
> +	if (!of_property_read_bool(pdev->dev.of_node, "amlogic,has-chip-id"))
> +		return -ENODEV;
> +
> +	/* node should be a syscon */
> +	regmap = syscon_node_to_regmap(pdev->dev.of_node);
> +	if (IS_ERR(regmap)) {
> +		dev_err(&pdev->dev, "failed to get regmap\n");

Syntax is:

return dev_err_probe()

> +		return -ENODEV;

Anyway wrong return code, use the real one you got.

> +	}
> +
> +	sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
> +	if (!sm_np) {
> +		dev_err(&pdev->dev, "no secure-monitor node found\n");
> +		return -ENODEV;

-EINVAL

> +	}
> +
> +	fw = meson_sm_get(sm_np);
> +	of_node_put(sm_np);
> +	if (!fw) {
> +		dev_info(&pdev->dev, "secure-monitor device not ready, probe later\n");

No, you never print messages on deferred probe.

> +		return -EPROBE_DEFER;
> +	}
> +
> +	ret = regmap_read(regmap, AO_SEC_SOCINFO_OFFSET, &socinfo.raw);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (!socinfo.raw) {
> +		dev_err(&pdev->dev, "invalid regmap chipid value\n");
> +		return -EINVAL;
> +	}
> +
> +	soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr),
> +				    GFP_KERNEL);
> +	if (!soc_dev_attr)
> +		return -ENOMEM;
> +
> +	soc_dev_attr->serial_number = socinfo_get_chipid(&pdev->dev, fw, &socinfo);
> +
> +	soc_dev_attr->family = "Amlogic Meson";
> +	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%x:%x - %x:%x",
> +					   socinfo.v1.major_id,
> +					   socinfo.v1.chip_rev,
> +					   socinfo.v1.pack_id,
> +					   (socinfo.v1.reserved<<4) + socinfo.v1.layout_ver);
> +	soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "%s (%s)",
> +					 socinfo_v1_to_soc_id(socinfo),
> +					 socinfo_v1_to_package_id(socinfo));
> +
> +	soc_dev = soc_device_register(soc_dev_attr);
> +
> +
> +	if (IS_ERR(soc_dev)) {
> +		kfree(soc_dev_attr->revision);
> +		kfree_const(soc_dev_attr->soc_id);
> +		kfree(soc_dev_attr);

That's a double free. This was not tested.

> +		return PTR_ERR(soc_dev);
> +	}
> +
> +	dev = soc_device_to_device(soc_dev);
> +	platform_set_drvdata(pdev, soc_dev);
> +
> +	dev_info(dev, "Amlogic Meson %s Revision %x:%x (%x:%x) Detected (SM)\n",
> +			soc_dev_attr->soc_id,
> +			socinfo.v1.major_id,
> +			socinfo.v1.chip_rev,
> +			socinfo.v1.pack_id,
> +			(socinfo.v1.reserved<<4) + socinfo.v1.layout_ver);
> +
> +	return PTR_ERR_OR_ZERO(dev);
> +}
> +
> +
> +static int meson_gx_socinfo_sm_remove(struct platform_device *pdev)
> +{
> +	struct soc_device *soc_dev = platform_get_drvdata(pdev);
> +
> +	soc_device_unregister(soc_dev);

If you free the memory in probe() error path, why you did not decide to
free it here as well? It is symmetrical, so this should make you wonder
- error path is wrong.


Best regards,
Krzysztof