Re: [PATCH v9 7/7] remoteproc: stm32: Add support of an OP-TEE TA to load the firmware

[Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>]

Hello Mathieu,

On 9/13/24 18:03, Mathieu Poirier wrote:
> On Fri, Aug 30, 2024 at 11:51:47AM +0200, Arnaud Pouliquen wrote:
>> The new TEE remoteproc driver is used to manage remote firmware in a
>> secure, trusted context. The 'st,stm32mp1-m4-tee' compatibility is
>> introduced to delegate the loading of the firmware to the trusted
>> execution context. In such cases, the firmware should be signed and
>> adhere to the image format defined by the TEE.
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>> ---
>>  drivers/remoteproc/stm32_rproc.c | 63 ++++++++++++++++++++++++++++++--
>>  1 file changed, 60 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
>> index 79c638936163..400a7a93b1c9 100644
>> --- a/drivers/remoteproc/stm32_rproc.c
>> +++ b/drivers/remoteproc/stm32_rproc.c
>> @@ -18,6 +18,7 @@
>>  #include <linux/pm_wakeirq.h>
>>  #include <linux/regmap.h>
>>  #include <linux/remoteproc.h>
>> +#include <linux/remoteproc_tee.h>
>>  #include <linux/reset.h>
>>  #include <linux/slab.h>
>>  #include <linux/workqueue.h>
>> @@ -257,6 +258,19 @@ static int stm32_rproc_release(struct rproc *rproc)
>>  	return 0;
>>  }
>>  
>> +static int stm32_rproc_tee_stop(struct rproc *rproc)
>> +{
>> +	int err;
>> +
>> +	stm32_rproc_request_shutdown(rproc);
>> +
>> +	err = tee_rproc_stop(rproc);
>> +	if (err)
>> +		return err;
>> +
>> +	return stm32_rproc_release(rproc);
>> +}
>> +
>>  static int stm32_rproc_prepare(struct rproc *rproc)
>>  {
>>  	struct device *dev = rproc->dev.parent;
>> @@ -693,8 +707,20 @@ static const struct rproc_ops st_rproc_ops = {
>>  	.get_boot_addr	= rproc_elf_get_boot_addr,
>>  };
>>  
>> +static const struct rproc_ops st_rproc_tee_ops = {
>> +	.prepare	= stm32_rproc_prepare,
>> +	.start		= tee_rproc_start,
>> +	.stop		= stm32_rproc_tee_stop,
>> +	.kick		= stm32_rproc_kick,
>> +	.load		= tee_rproc_load_fw,
>> +	.parse_fw	= tee_rproc_parse_fw,
>> +	.find_loaded_rsc_table = tee_rproc_find_loaded_rsc_table,
>> +
>> +};
>> +
>>  static const struct of_device_id stm32_rproc_match[] = {
>>  	{ .compatible = "st,stm32mp1-m4" },
>> +	{ .compatible = "st,stm32mp1-m4-tee" },
>>  	{},
>>  };
>>  MODULE_DEVICE_TABLE(of, stm32_rproc_match);
>> @@ -853,17 +879,42 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>>  	struct device *dev = &pdev->dev;
>>  	struct stm32_rproc *ddata;
>>  	struct device_node *np = dev->of_node;
>> +	struct tee_rproc *trproc = NULL;
>>  	struct rproc *rproc;
>>  	unsigned int state;
>> +	u32 proc_id;
>>  	int ret;
>>  
>>  	ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
>>  	if (ret)
>>  		return ret;
>>  
>> -	rproc = devm_rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
>> -	if (!rproc)
>> -		return -ENOMEM;
>> +	if (of_device_is_compatible(np, "st,stm32mp1-m4-tee")) {
>> +		/*
>> +		 * Delegate the firmware management to the secure context.
>> +		 * The firmware loaded has to be signed.
>> +		 */
>> +		ret = of_property_read_u32(np, "st,proc-id", &proc_id);
>> +		if (ret) {
>> +			dev_err(dev, "failed to read st,rproc-id property\n");
>> +			return ret;
>> +		}
>> +
>> +		rproc = devm_rproc_alloc(dev, np->name, &st_rproc_tee_ops, NULL, sizeof(*ddata));
>> +		if (!rproc)
>> +			return -ENOMEM;
>> +
>> +		trproc = tee_rproc_register(dev, rproc, proc_id);
>> +		if (IS_ERR(trproc)) {
>> +			dev_err_probe(dev, PTR_ERR(trproc),
>> +				      "signed firmware not supported by TEE\n");
>> +			return PTR_ERR(trproc);
>> +		}
>> +	} else {
>> +		rproc = devm_rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
>> +		if (!rproc)
>> +			return -ENOMEM;
>> +	}
>>  
>>  	ddata = rproc->priv;
>>  
>> @@ -915,6 +966,9 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>>  		dev_pm_clear_wake_irq(dev);
>>  		device_init_wakeup(dev, false);
>>  	}
>> +	if (trproc)
> 
>         if (rproc->tee_interface)
> 
> I am done reviewing this set.

Thanks for the review, I will sent a V10 ASAP to fix this set.
Extra information: the OP-TEE that introduces the new
PTA_REMOTEPROC_RELEASE command has been merged.

Regards,
Arnaud

> 
>> +		tee_rproc_unregister(trproc);
>> +
>>  	return ret;
>>  }
>>  
>> @@ -935,6 +989,9 @@ static void stm32_rproc_remove(struct platform_device *pdev)
>>  		dev_pm_clear_wake_irq(dev);
>>  		device_init_wakeup(dev, false);
>>  	}
>> +	if (rproc->tee_interface)
>> +		tee_rproc_unregister(rproc->tee_interface);
>> +
>>  }
>>  
>>  static int stm32_rproc_suspend(struct device *dev)
>> -- 
>> 2.25.1
>>