Re: [PATCH v2 4/6] tee: optee: Register TEE devices on the platform bus

[Harshal Dev]

+ op-tee@xxxxxxxxxxxxxxxxxxxxxxxxx, Jens Wiklander <jens.wiklander@xxxxxxxxxxxxxxxx>

On 11-11-2026 07:47 pm, Harshal Dev wrote:
> The Qualcomm Inline Crypto Engine (ICE) driver is an independent platform
> driver which polls on availability of a TEE interface (SCM driver) before
> checking if the ICE secure service is supported by QTEE by querying the
> qcom_scm_ice_available() API.
> 
> The TEE subsystem currently does not provide any way to notify regarding
> the availability of a TEE interface, i.e. whether QCOMTEE or OPTEE have
> probed. And so when migrating to the TEE subsystem via an ICE TEE client
> driver, ICE needs to defer probe until the OPTEE ICE Pseudo TA becomes
> available on the TEE bus. This means that for OPTEE builds without the
> ICE PTA, the ICE driver would indefintely defer probe and the dependent
> UFS/SDHC storage driver will fail to come online.
> 
> Add support for optionally registering the back-end TEE devices which
> represent a particular TEE (say OPTEE) on the platform bus via the
> tee_platform_device_register() API. This allows drivers which poll on
> TEE secure interface availability to be notified even if the TEE service
> itself is not supported.
> 
> Signed-off-by: Harshal Dev <harshal.dev@xxxxxxxxxxxxxxxx>
> ---
>  MAINTAINERS                                |  1 +
>  drivers/firmware/qcom/qcom_ice_tee.c       | 41 ++++++++++++++++++++++++++++++
>  drivers/soc/qcom/Kconfig                   |  1 +
>  drivers/soc/qcom/ice.c                     |  9 ++++++-
>  drivers/tee/optee/ffa_abi.c                |  8 ++++++
>  drivers/tee/optee/smc_abi.c                |  8 ++++++
>  drivers/tee/tee_core.c                     | 21 +++++++++++++++
>  include/linux/firmware/qcom/qcom_ice_tee.h | 10 ++++++++
>  include/linux/tee_core.h                   |  9 +++++++
>  9 files changed, 107 insertions(+), 1 deletion(-)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1132e456488b..06dba76996b8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -23013,6 +23013,7 @@ L:	linux-arm-msm@xxxxxxxxxxxxxxx
>  L:	linux-crypto@xxxxxxxxxxxxxxx
>  S:	Maintained
>  F:	drivers/firmware/qcom/qcom_ice_tee.c
> +F:	include/linux/firmware/qcom/qcom_ice_tee.h
>  
>  QUALCOMM INTERCONNECT BWMON DRIVER
>  M:	Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> diff --git a/drivers/firmware/qcom/qcom_ice_tee.c b/drivers/firmware/qcom/qcom_ice_tee.c
> index 694aa05847f0..39f7094439d9 100644
> --- a/drivers/firmware/qcom/qcom_ice_tee.c
> +++ b/drivers/firmware/qcom/qcom_ice_tee.c
> @@ -5,6 +5,7 @@
>  
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> +#include <linux/platform_device.h>
>  #include <linux/slab.h>
>  #include <linux/tee_drv.h>
>  #include <linux/uuid.h>
> @@ -22,6 +23,9 @@
>  
>  #define TEE_NUM_PARAMS				4
>  
> +/* This represents the back-end OPTEE device */
> +static struct device *__teedev;
> +
>  struct qcom_ice_tee_private {
>  	struct device *dev;
>  	struct tee_context *ctx;
> @@ -281,6 +285,18 @@ static int qcom_ice_tee_import_key(struct device *dev,
>  					     lt_key, lt_key_size);
>  }
>  
> +bool qcom_ice_tee_is_available(void)
> +{
> +	/*
> +	 * Paired with smp_load_acquire() in qcom_ice_plat_probe().
> +	 *
> +	 * This marks the availability of the OPTEE interface informing the
> +	 * polling ICE driver that the platform supports a TEE.
> +	 */
> +	return !!smp_load_acquire(&__teedev);
> +}
> +EXPORT_SYMBOL_GPL(qcom_ice_tee_is_available);
> +
>  static bool qcom_ice_tee_has_wrapped_key_support(struct device *dev)
>  {
>  	struct qcom_ice_tee_private *data = dev_get_drvdata(dev);
> @@ -398,5 +414,30 @@ static struct tee_client_driver qcom_ice_tee_driver = {
>  
>  module_tee_client_driver(qcom_ice_tee_driver);
>  
> +static int qcom_ice_plat_probe(struct platform_device *pdev)
> +{
> +	/* Paired with smp_load_acquire() in qcom_ice_tee_is_available() */
> +	smp_store_release(&__teedev, &pdev->dev);
> +	return 0;
> +}
> +
> +static const struct platform_device_id qcom_ice_plat_id_table[] = {
> +	{
> +		.name = "optee",
> +	},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(platform, qcom_ice_plat_id_table);
> +
> +static struct platform_driver qcom_ice_plat_driver = {
> +	.probe = qcom_ice_plat_probe,
> +	.id_table = qcom_ice_plat_id_table,
> +	.driver = {
> +		.name = "qcom-ice-plat",
> +	},
> +};
> +
> +module_platform_driver(qcom_ice_plat_driver);
> +
>  MODULE_LICENSE("GPL");
>  MODULE_DESCRIPTION("Qualcomm ICE TEE driver");
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 535c8619197b..8dc75c252f52 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -296,6 +296,7 @@ endif
>  config QCOM_INLINE_CRYPTO_ENGINE
>  	tristate
>  	select QCOM_SCM
> +	select QCOM_ICE_TEE
>  
>  config QCOM_KRYO_L2_ACCESSORS
>  	bool
> diff --git a/drivers/soc/qcom/ice.c b/drivers/soc/qcom/ice.c
> index 452896b1858f..4844621b7497 100644
> --- a/drivers/soc/qcom/ice.c
> +++ b/drivers/soc/qcom/ice.c
> @@ -18,6 +18,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/xarray.h>
>  
> +#include <linux/firmware/qcom/qcom_ice_tee.h>
>  #include <linux/firmware/qcom/qcom_scm.h>
>  
>  #include <soc/qcom/ice.h>
> @@ -132,7 +133,13 @@ static bool qcom_ice_tz_ops_registered(void)
>  
>  static bool qcom_ice_tz_is_available(void)
>  {
> -	return qcom_scm_is_available();
> +	/*
> +	 * Both back-ends should be available before we check for
> +	 * qcom_ice_tz_ops_registered(), otherwise we could pre-maturely
> +	 * assume that TZ does not provide any ICE secure interface.
> +	 */
> +	return (qcom_scm_is_available() & qcom_ice_tee_is_available());
> +
>  }
>  
>  static int qcom_ice_tz_invalidate_key(u32 index)
> diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> index 702da7d98fbc..2c0065f3d9e4 100644
> --- a/drivers/tee/optee/ffa_abi.c
> +++ b/drivers/tee/optee/ffa_abi.c
> @@ -1177,6 +1177,14 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
>  	if (rc)
>  		goto err_unregister_devices;
>  
> +	/*
> +	 * Device should only be visible on the platform bus once the
> +	 * child devices have already been enumerated on the TEE bus.
> +	 */
> +	rc = tee_platform_device_register(optee->teedev, "optee");
> +	if (rc)
> +		goto err_unregister_devices;
> +
>  	INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
>  	optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
>  	blocking_notifier_chain_register(&optee_rpmb_intf_added,
> diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> index 51624443359b..85ee76173982 100644
> --- a/drivers/tee/optee/smc_abi.c
> +++ b/drivers/tee/optee/smc_abi.c
> @@ -1920,6 +1920,14 @@ static int optee_probe(struct platform_device *pdev)
>  	if (rc)
>  		goto err_disable_shm_cache;
>  
> +	/*
> +	 * Device should only be visible on the platform bus once the
> +	 * child devices have already been enumerated on the TEE bus.
> +	 */
> +	rc = tee_platform_device_register(optee->teedev, "optee");
> +	if (rc)
> +		goto err_disable_shm_cache;
> +
>  	INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
>  	optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
>  	blocking_notifier_chain_register(&optee_rpmb_intf_added,
> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> index 1aac50c7c1de..0d3c266b29c7 100644
> --- a/drivers/tee/tee_core.c
> +++ b/drivers/tee/tee_core.c
> @@ -10,6 +10,7 @@
>  #include <linux/fs.h>
>  #include <linux/idr.h>
>  #include <linux/module.h>
> +#include <linux/platform_device.h>
>  #include <linux/overflow.h>
>  #include <linux/slab.h>
>  #include <linux/tee_core.h>
> @@ -1225,6 +1226,26 @@ int tee_device_register(struct tee_device *teedev)
>  }
>  EXPORT_SYMBOL_GPL(tee_device_register);
>  
> +static void plat_tee_free(void *data)
> +{
> +	struct platform_device *plat_dev = data;
> +
> +	platform_device_unregister(plat_dev);
> +}
> +
> +int tee_platform_device_register(struct tee_device *teedev, const char *teename)
> +{
> +	struct platform_device *plat_dev;
> +
> +	plat_dev = platform_device_register_data(&teedev->dev, teename,
> +						 PLATFORM_DEVID_NONE, NULL, 0);
> +	if (IS_ERR(plat_dev))
> +		return PTR_ERR(plat_dev);
> +
> +	devm_add_action_or_reset(&teedev->dev, plat_tee_free, plat_dev);
> +	return 0;
> +}
> +
>  void tee_device_put(struct tee_device *teedev)
>  {
>  	mutex_lock(&teedev->mutex);
> diff --git a/include/linux/firmware/qcom/qcom_ice_tee.h b/include/linux/firmware/qcom/qcom_ice_tee.h
> new file mode 100644
> index 000000000000..a5906c5d4e39
> --- /dev/null
> +++ b/include/linux/firmware/qcom/qcom_ice_tee.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +#ifndef __QCOM_ICE_TEE
> +#define __QCOM_ICE_TEE
> +
> +bool qcom_ice_tee_is_available(void);
> +
> +#endif /* __QCOM_ICE_TEE */
> diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
> index f993d5118edd..d5310b404c1e 100644
> --- a/include/linux/tee_core.h
> +++ b/include/linux/tee_core.h
> @@ -205,6 +205,15 @@ struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
>   */
>  int tee_device_register(struct tee_device *teedev);
>  
> +/**
> + * tee_platform_device_register() - Registers a TEE platform device
> + * @teedev:	Device to register
> + * @teename:	Name of the TEE the device represents
> + *
> + * @returns: < 0 on failure
> + */
> +int tee_platform_device_register(struct tee_device *teedev, const char *teename);
> +
>  /**
>   * tee_device_unregister() - Removes a TEE device
>   * @teedev:	Device to unregister
>