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>
---
updates vs v9 revision:
- rename tee_interface to tee_rproc_itf
- in stm32_rproc_probe(), test and use rproc->tee_rproc_itf instead of
  trproc in the tee_rproc_unregister() call
- initialize release_fw ops
---
 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 288bd70c7861..cb7093de41df 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>
@@ -255,6 +256,19 @@ 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;
@@ -691,8 +705,20 @@ 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,
+	.release_fw	= tee_rproc_release_fw,
+};
+
 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);
@@ -851,17 +877,42 @@ 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;
 
@@ -913,6 +964,9 @@ static int stm32_rproc_probe(struct platform_device *pdev)
 		dev_pm_clear_wake_irq(dev);
 		device_init_wakeup(dev, false);
 	}
+	if (rproc->tee_rproc_itf)
+		tee_rproc_unregister(rproc->tee_rproc_itf);
+
 	return ret;
 }
 
@@ -933,6 +987,9 @@ static void stm32_rproc_remove(struct platform_device *pdev)
 		dev_pm_clear_wake_irq(dev);
 		device_init_wakeup(dev, false);
 	}
+	if (rproc->tee_rproc_itf)
+		tee_rproc_unregister(rproc->tee_rproc_itf);
+
 }
 
 static int stm32_rproc_suspend(struct device *dev)
-- 
2.25.1

On Wed, Oct 09, 2024 at 10:01:08AM +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>
> ---
> updates vs v9 revision:
> - rename tee_interface to tee_rproc_itf
> - in stm32_rproc_probe(), test and use rproc->tee_rproc_itf instead of
>   trproc in the tee_rproc_unregister() call
> - initialize release_fw ops
> ---
>  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 288bd70c7861..cb7093de41df 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>
> @@ -255,6 +256,19 @@ 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;
> @@ -691,8 +705,20 @@ 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,
> +	.release_fw	= tee_rproc_release_fw,
> +};
> +
>  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);
> @@ -851,17 +877,42 @@ 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;

The cleaner this patchset get, the more obvious it is (at least to me) that
struct tee_rproc needs to be changed to struct rproc_tee.  Otherwise I keep
wondering if this is coming from the TEE subsystem or the remoteproc subsystem.

>  	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);

This should return an integer rather than a struct tee_rproc * since the latter
is available through rproc->tee_rproc_itf.

In line with my comment above, this should be changed to rproc_tee_register()
since it belongs to the remoteproc subsystem.  Before when I asked for
tee_remoteproc.c to be changed to remoteproc_tee.c, I thought we could get by
without changing the inside but now I think it is clear that we can't - this
needs to be addressed.  

> +		if (IS_ERR(trproc)) {
> +			dev_err_probe(dev, PTR_ERR(trproc),
> +				      "signed firmware not supported by TEE\n");
> +			return PTR_ERR(trproc);

                        return dev_err_probe(...);
> +		}
> +	} else {
> +		rproc = devm_rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
> +		if (!rproc)
> +			return -ENOMEM;
> +	}
>  
>  	ddata = rproc->priv;
>  
> @@ -913,6 +964,9 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>  		dev_pm_clear_wake_irq(dev);
>  		device_init_wakeup(dev, false);
>  	}
> +	if (rproc->tee_rproc_itf)
> +		tee_rproc_unregister(rproc->tee_rproc_itf);
> +

If I read Bjorn's comment properly, this should probably be:

                rproc_tee_unregister(rproc);

with the if() inside the function.

>  	return ret;
>  }
>  
> @@ -933,6 +987,9 @@ static void stm32_rproc_remove(struct platform_device *pdev)
>  		dev_pm_clear_wake_irq(dev);
>  		device_init_wakeup(dev, false);
>  	}
> +	if (rproc->tee_rproc_itf)
> +		tee_rproc_unregister(rproc->tee_rproc_itf);
> +

Same here.

I am done reviewing this set.

Thanks,
Mathieu

>  }
>  
>  static int stm32_rproc_suspend(struct device *dev)
> -- 
> 2.25.1
>