[PATCH] crypto: ccp: Fix incorrect return type for psp_get_capability()

[PATCH] crypto: ccp: Fix incorrect return type for psp_get_capability()

[Yunseong Kim]

psp_get_capability() is declared as returning an 'unsigned int'. However,
it returns -ENODEV on failure when it cannot access the device registers
(i.e., when ioread32 returns 0xffffffff).

Since -ENODEV is a negative value, returning it from a function declared as
'unsigned int' results in an implicit cast to a large positive integer.
This prevents the caller psp_dev_init() from correctly detecting the
error condition, leading to improper error handling.

Fix this by changing the return type of psp_get_capability() to 'int'.

Additionally, change the type of the local variable 'val' to 'u32', which
is more appropriate for register access, and reformat the long dev_notice
line to adhere to kernel coding style guidelines.

Signed-off-by: Yunseong Kim <ysk@kzalloc.com>
---
 drivers/crypto/ccp/psp-dev.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 1c5a7189631e..84dde53db25b 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -140,9 +140,9 @@ static irqreturn_t psp_irq_handler(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static unsigned int psp_get_capability(struct psp_device *psp)
+static int psp_get_capability(struct psp_device *psp)
 {
-	unsigned int val = ioread32(psp->io_regs + psp->vdata->feature_reg);
+	u32 val = ioread32(psp->io_regs + psp->vdata->feature_reg);
 
 	/*
 	 * Check for a access to the registers.  If this read returns
@@ -152,7 +152,8 @@ static unsigned int psp_get_capability(struct psp_device *psp)
 	 * could get properly initialized).
 	 */
 	if (val == 0xffffffff) {
-		dev_notice(psp->dev, "psp: unable to access the device: you might be running a broken BIOS.\n");
+		dev_notice(psp->dev,
+			"psp: unable to access the device: you might be running a broken BIOS.\n");
 		return -ENODEV;
 	}
 	psp->capability.raw = val;
-- 
2.51.0

Re: [PATCH] crypto: ccp: Fix incorrect return type for psp_get_capability()

[Mario Limonciello]

On 9/3/25 8:55 AM, Yunseong Kim wrote:
> psp_get_capability() is declared as returning an 'unsigned int'. However,
> it returns -ENODEV on failure when it cannot access the device registers
> (i.e., when ioread32 returns 0xffffffff).
> 
> Since -ENODEV is a negative value, returning it from a function declared as
> 'unsigned int' results in an implicit cast to a large positive integer.
> This prevents the caller psp_dev_init() from correctly detecting the
> error condition, leading to improper error handling.
> 
> Fix this by changing the return type of psp_get_capability() to 'int'.
> 
> Additionally, change the type of the local variable 'val' to 'u32', which
> is more appropriate for register access, and reformat the long dev_notice
> line to adhere to kernel coding style guidelines.
> 
> Signed-off-by: Yunseong Kim <ysk@kzalloc.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>

> ---
>   drivers/crypto/ccp/psp-dev.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index 1c5a7189631e..84dde53db25b 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -140,9 +140,9 @@ static irqreturn_t psp_irq_handler(int irq, void *data)
>   	return IRQ_HANDLED;
>   }
>   
> -static unsigned int psp_get_capability(struct psp_device *psp)
> +static int psp_get_capability(struct psp_device *psp)
>   {
> -	unsigned int val = ioread32(psp->io_regs + psp->vdata->feature_reg);
> +	u32 val = ioread32(psp->io_regs + psp->vdata->feature_reg);
>   
>   	/*
>   	 * Check for a access to the registers.  If this read returns
> @@ -152,7 +152,8 @@ static unsigned int psp_get_capability(struct psp_device *psp)
>   	 * could get properly initialized).
>   	 */
>   	if (val == 0xffffffff) {
> -		dev_notice(psp->dev, "psp: unable to access the device: you might be running a broken BIOS.\n");
> +		dev_notice(psp->dev,
> +			"psp: unable to access the device: you might be running a broken BIOS.\n");
>   		return -ENODEV;
>   	}
>   	psp->capability.raw = val;