Re: [PATCH] soc: qcom: ice: Remove platform_driver support and expose as a pure library

[Manivannan Sadhasivam]

On Tue, Feb 17, 2026 at 10:03:27AM +0530, Neeraj Soni wrote:
> 
> 
> On 2/3/2026 1:40 PM, Manivannan Sadhasivam wrote:
> > On Tue, Feb 03, 2026 at 01:37:12PM +0530, Manivannan Sadhasivam wrote:
> >> The current platform driver design causes probe ordering races with clients
> >> (UFS, eMMC) due to ICE's dependency on SCM firmware calls. If ICE probe
> >> fails (missing ICE SCM or DT registers), devm_of_qcom_ice_get() loops with
> >> -EPROBE_DEFER, leaving clients non-functional even when ICE should be
> >> gracefully disabled. devm_of_qcom_ice_get() cannot know if the ICE driver
> >> probe has failed due to above reasons or it is waiting for the SCM driver.
> >>
> >> Moreover, there is no devlink dependency between ICE and client drivers
> >> as 'qcom,ice' is not considered as a DT 'supplier'. So the client drivers
> >> have no idea of when the ICE driver is going to probe.
> >>
> >> To avoid all this hassle, remove the platform driver support altogether and
> >> just expose the ICE driver as a pure library to client drivers. With this
> >> design, when devm_of_qcom_ice_get() is called, it will check if the ICE
> >> instance is available or not. If not, it will create one based on the ICE
> >> DT node, increase the refcount and return the handle. When the next client
> >> calls the API again, the ICE instance would be available. So this function
> >> will just increment the refcount and return the instance.
> >>
> >> Finally, when the client devices get destroyed, refcount will be
> >> decremented and finally the cleanup will happen once all clients are
> >> destroyed.
> >>
> >> For the clients using the old DT binding of providing the separate 'ice'
> >> register range in their node, this change has no impact.
> >>
> >> Cc: stable@xxxxxxxxxxxxxxx
> >> Cc: Abel Vesa <abel.vesa@xxxxxxxxxxxxxxxx>
> >> Reported-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> >> Fixes: 2afbf43a4aec ("soc: qcom: Make the Qualcomm UFS/SDCC ICE a dedicated driver")
> >> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
> >> ---
> >>  drivers/soc/qcom/ice.c | 100 ++++++++++++++++-------------------------
> >>  1 file changed, 39 insertions(+), 61 deletions(-)
> >>
> >> diff --git a/drivers/soc/qcom/ice.c b/drivers/soc/qcom/ice.c
> >> index b203bc685cad..b5a9cf8de6e4 100644
> >> --- a/drivers/soc/qcom/ice.c
> >> +++ b/drivers/soc/qcom/ice.c
> >> @@ -107,12 +107,16 @@ struct qcom_ice {
> >>  	struct device *dev;
> >>  	void __iomem *base;
> >>  
> >> +	struct kref refcount;
> >>  	struct clk *core_clk;
> >>  	bool use_hwkm;
> >>  	bool hwkm_init_complete;
> >>  	u8 hwkm_version;
> >>  };
> >>  
> >> +static DEFINE_MUTEX(ice_mutex);
> >> +struct qcom_ice *ice_handle;
> >> +
> >>  static bool qcom_ice_check_supported(struct qcom_ice *ice)
> >>  {
> >>  	u32 regval = qcom_ice_readl(ice, QCOM_ICE_REG_VERSION);
> >> @@ -599,8 +603,8 @@ static struct qcom_ice *qcom_ice_create(struct device *dev,
> >>   * This function will provide an ICE instance either by creating one for the
> >>   * consumer device if its DT node provides the 'ice' reg range and the 'ice'
> >>   * clock (for legacy DT style). On the other hand, if consumer provides a
> >> - * phandle via 'qcom,ice' property to an ICE DT, the ICE instance will already
> >> - * be created and so this function will return that instead.
> >> + * phandle via 'qcom,ice' property to an ICE DT node, then the ICE instance will
> >> + * be created if not already done and will be returned.
> >>   *
> >>   * Return: ICE pointer on success, NULL if there is no ICE data provided by the
> >>   * consumer or ERR_PTR() on error.
> >> @@ -611,11 +615,12 @@ static struct qcom_ice *of_qcom_ice_get(struct device *dev)
> >>  	struct qcom_ice *ice;
> >>  	struct resource *res;
> >>  	void __iomem *base;
> >> -	struct device_link *link;
> >>  
> >>  	if (!dev || !dev->of_node)
> >>  		return ERR_PTR(-ENODEV);
> >>  
> >> +	guard(mutex)(&ice_mutex);
> >> +
> >>  	/*
> >>  	 * In order to support legacy style devicetree bindings, we need
> >>  	 * to create the ICE instance using the consumer device and the reg
> >> @@ -631,6 +636,16 @@ static struct qcom_ice *of_qcom_ice_get(struct device *dev)
> >>  		return qcom_ice_create(&pdev->dev, base);
> >>  	}
> >>  
> >> +	/*
> >> +	 * If the ICE node has been initialized already, just increase the
> >> +	 * refcount and return the handle.
> >> +	 */
> >> +	if (ice_handle) {
> >> +		kref_get(&ice_handle->refcount);
> >> +
> >> +		return ice_handle;
> 
> How will this work for a device using both UFS and eMMC storage (one being primary storage
> and other being secondary)? UFS and eMMC will have seperate ICE DT node so returning same
> handle to both clients will not be correct.
> 

I'm not aware of any platforms using separate ICE nodes. All are using shared
node only. Which platform are you referring to?

- Mani

> >> +	}
> >> +
> >>  	/*
> >>  	 * If the consumer node does not provider an 'ice' reg range
> >>  	 * (legacy DT binding), then it must at least provide a phandle
> >> @@ -643,41 +658,43 @@ static struct qcom_ice *of_qcom_ice_get(struct device *dev)
> >>  
> >>  	pdev = of_find_device_by_node(node);
> >>  	if (!pdev) {
> >> -		dev_err(dev, "Cannot find device node %s\n", node->name);
> >> +		dev_err(dev, "Cannot find ICE platform device\n");
> >> +		platform_device_put(pdev);
> > 
> > This somehow slipped in...
> > 
> > - Mani
> > 
> >>  		return ERR_PTR(-EPROBE_DEFER);
> >>  	}
> >>  
> >> -	ice = platform_get_drvdata(pdev);
> >> -	if (!ice) {
> >> -		dev_err(dev, "Cannot get ice instance from %s\n",
> >> -			dev_name(&pdev->dev));
> >> +	base = devm_platform_ioremap_resource(pdev, 0);
> >> +	if (IS_ERR(base)) {
> >> +		dev_warn(&pdev->dev, "ICE registers not found\n");
> >>  		platform_device_put(pdev);
> >> -		return ERR_PTR(-EPROBE_DEFER);
> >> +		return base;
> >>  	}
> >>  
> >> -	link = device_link_add(dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
> >> -	if (!link) {
> >> -		dev_err(&pdev->dev,
> >> -			"Failed to create device link to consumer %s\n",
> >> -			dev_name(dev));
> >> +	ice = qcom_ice_create(&pdev->dev, base);
> >> +	if (IS_ERR(ice)) {
> >>  		platform_device_put(pdev);
> >> -		ice = ERR_PTR(-EINVAL);
> >> +		return ice_handle;
> >>  	}
> >>  
> >> -	return ice;
> >> +	ice_handle = ice;
> >> +	kref_init(&ice_handle->refcount);
> >> +
> >> +	return ice_handle;
> >>  }
> >>  
> >> -static void qcom_ice_put(const struct qcom_ice *ice)
> >> +static void qcom_ice_put(struct kref *kref)
> >>  {
> >> -	struct platform_device *pdev = to_platform_device(ice->dev);
> >> -
> >> -	if (!platform_get_resource_byname(pdev, IORESOURCE_MEM, "ice"))
> >> -		platform_device_put(pdev);
> >> +	platform_device_put(to_platform_device(ice_handle->dev));
> >> +	ice_handle = NULL;
> >>  }
> >>  
> >>  static void devm_of_qcom_ice_put(struct device *dev, void *res)
> >>  {
> >> -	qcom_ice_put(*(struct qcom_ice **)res);
> >> +	const struct qcom_ice *ice = *(struct qcom_ice **)res;
> >> +	struct platform_device *pdev = to_platform_device(ice->dev);
> >> +
> >> +	if (!platform_get_resource_byname(pdev, IORESOURCE_MEM, "ice"))
> >> +		kref_put(&ice_handle->refcount, qcom_ice_put);
> >>  }
> >>  
> >>  /**
> >> @@ -713,42 +730,3 @@ struct qcom_ice *devm_of_qcom_ice_get(struct device *dev)
> >>  	return ice;
> >>  }
> >>  EXPORT_SYMBOL_GPL(devm_of_qcom_ice_get);
> >> -
> >> -static int qcom_ice_probe(struct platform_device *pdev)
> >> -{
> >> -	struct qcom_ice *engine;
> >> -	void __iomem *base;
> >> -
> >> -	base = devm_platform_ioremap_resource(pdev, 0);
> >> -	if (IS_ERR(base)) {
> >> -		dev_warn(&pdev->dev, "ICE registers not found\n");
> >> -		return PTR_ERR(base);
> >> -	}
> >> -
> >> -	engine = qcom_ice_create(&pdev->dev, base);
> >> -	if (IS_ERR(engine))
> >> -		return PTR_ERR(engine);
> >> -
> >> -	platform_set_drvdata(pdev, engine);
> >> -
> >> -	return 0;
> >> -}
> >> -
> >> -static const struct of_device_id qcom_ice_of_match_table[] = {
> >> -	{ .compatible = "qcom,inline-crypto-engine" },
> >> -	{ },
> >> -};
> >> -MODULE_DEVICE_TABLE(of, qcom_ice_of_match_table);
> >> -
> >> -static struct platform_driver qcom_ice_driver = {
> >> -	.probe	= qcom_ice_probe,
> >> -	.driver = {
> >> -		.name = "qcom-ice",
> >> -		.of_match_table = qcom_ice_of_match_table,
> >> -	},
> >> -};
> >> -
> >> -module_platform_driver(qcom_ice_driver);
> >> -
> >> -MODULE_DESCRIPTION("Qualcomm Inline Crypto Engine driver");
> >> -MODULE_LICENSE("GPL");
> >> -- 
> >> 2.51.0
> >>
> > 
> Regards
> Neeraj

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