[PATCH 1/2] hwrng: iproc-rng200: Fix disable of the block.

[PATCH 1/2] hwrng: iproc-rng200: Fix disable of the block.

[matthias.bgg]

From: Matthias Brugger <mbrugger@suse.com>

When trying to disable the block we bitwise or the control
register with value zero. This will leave the block always turned on.
Fix this by setting the corresponding bit to zero.

Fixes: c83d45d5685f ("hwrng: iproc-rng200 - Add Broadcom IPROC RNG driver")
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---

 drivers/char/hw_random/iproc-rng200.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
index 01583faf9893..e106ce3c0146 100644
--- a/drivers/char/hw_random/iproc-rng200.c
+++ b/drivers/char/hw_random/iproc-rng200.c
@@ -28,7 +28,6 @@
 #define RNG_CTRL_OFFSET					0x00
 #define RNG_CTRL_RNG_RBGEN_MASK				0x00001FFF
 #define RNG_CTRL_RNG_RBGEN_ENABLE			0x00000001
-#define RNG_CTRL_RNG_RBGEN_DISABLE			0x00000000
 
 #define RNG_SOFT_RESET_OFFSET				0x04
 #define RNG_SOFT_RESET					0x00000001
@@ -61,7 +60,7 @@ static void iproc_rng200_restart(void __iomem *rng_base)
 	/* Disable RBG */
 	val = ioread32(rng_base + RNG_CTRL_OFFSET);
 	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
-	val |= RNG_CTRL_RNG_RBGEN_DISABLE;
+	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
 	iowrite32(val, rng_base + RNG_CTRL_OFFSET);
 
 	/* Clear all interrupt status */
@@ -174,7 +173,7 @@ static void iproc_rng200_cleanup(struct hwrng *rng)
 	/* Disable RNG hardware */
 	val = ioread32(priv->base + RNG_CTRL_OFFSET);
 	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
-	val |= RNG_CTRL_RNG_RBGEN_DISABLE;
+	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
 	iowrite32(val, priv->base + RNG_CTRL_OFFSET);
 }
 
-- 
2.29.2

[PATCH 2/2] hwrng: iproc-rng200: Move enable/disable in separate function

[matthias.bgg]

From: Matthias Brugger <mbrugger@suse.com>

We are calling the same code for enable and disable the block in various
parts of the driver. Put that code into a new function to reduce code
duplication.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>

---

 drivers/char/hw_random/iproc-rng200.c | 37 ++++++++++++---------------
 1 file changed, 17 insertions(+), 20 deletions(-)

diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
index e106ce3c0146..3367b26085e8 100644
--- a/drivers/char/hw_random/iproc-rng200.c
+++ b/drivers/char/hw_random/iproc-rng200.c
@@ -53,15 +53,26 @@ struct iproc_rng200_dev {
 
 #define to_rng_priv(rng)	container_of(rng, struct iproc_rng200_dev, rng)
 
-static void iproc_rng200_restart(void __iomem *rng_base)
+static void iproc_rng200_enable(void __iomem *rng_base, bool enable)
 {
 	uint32_t val;
 
-	/* Disable RBG */
 	val = ioread32(rng_base + RNG_CTRL_OFFSET);
 	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
-	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
+
+	if (enable)
+		val |= RNG_CTRL_RNG_RBGEN_ENABLE;
+	else
+		val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
+
 	iowrite32(val, rng_base + RNG_CTRL_OFFSET);
+}
+
+static void iproc_rng200_restart(void __iomem *rng_base)
+{
+	uint32_t val;
+
+	iproc_rng200_enable(rng_base, false);
 
 	/* Clear all interrupt status */
 	iowrite32(0xFFFFFFFFUL, rng_base + RNG_INT_STATUS_OFFSET);
@@ -83,11 +94,7 @@ static void iproc_rng200_restart(void __iomem *rng_base)
 	val &= ~RBG_SOFT_RESET;
 	iowrite32(val, rng_base + RBG_SOFT_RESET_OFFSET);
 
-	/* Enable RBG */
-	val = ioread32(rng_base + RNG_CTRL_OFFSET);
-	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
-	val |= RNG_CTRL_RNG_RBGEN_ENABLE;
-	iowrite32(val, rng_base + RNG_CTRL_OFFSET);
+	iproc_rng200_enable(rng_base, true);
 }
 
 static int iproc_rng200_read(struct hwrng *rng, void *buf, size_t max,
@@ -154,13 +161,8 @@ static int iproc_rng200_read(struct hwrng *rng, void *buf, size_t max,
 static int iproc_rng200_init(struct hwrng *rng)
 {
 	struct iproc_rng200_dev *priv = to_rng_priv(rng);
-	uint32_t val;
 
-	/* Setup RNG. */
-	val = ioread32(priv->base + RNG_CTRL_OFFSET);
-	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
-	val |= RNG_CTRL_RNG_RBGEN_ENABLE;
-	iowrite32(val, priv->base + RNG_CTRL_OFFSET);
+	iproc_rng200_enable(priv->base, true);
 
 	return 0;
 }
@@ -168,13 +170,8 @@ static int iproc_rng200_init(struct hwrng *rng)
 static void iproc_rng200_cleanup(struct hwrng *rng)
 {
 	struct iproc_rng200_dev *priv = to_rng_priv(rng);
-	uint32_t val;
 
-	/* Disable RNG hardware */
-	val = ioread32(priv->base + RNG_CTRL_OFFSET);
-	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
-	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
-	iowrite32(val, priv->base + RNG_CTRL_OFFSET);
+	iproc_rng200_enable(priv->base, false);
 }
 
 static int iproc_rng200_probe(struct platform_device *pdev)
-- 
2.29.2

Re: [PATCH 1/2] hwrng: iproc-rng200: Fix disable of the block.

[Florian Fainelli]

On 12/14/20 8:04 AM, matthias.bgg@kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
> 
> When trying to disable the block we bitwise or the control
> register with value zero. This will leave the block always turned on.
> Fix this by setting the corresponding bit to zero.
> 
> Fixes: c83d45d5685f ("hwrng: iproc-rng200 - Add Broadcom IPROC RNG driver")
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH 2/2] hwrng: iproc-rng200: Move enable/disable in separate function

[Florian Fainelli]

On 12/14/20 8:04 AM, matthias.bgg@kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
> 
> We are calling the same code for enable and disable the block in various
> parts of the driver. Put that code into a new function to reduce code
> duplication.
> 
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
> 
> ---
> 
>  drivers/char/hw_random/iproc-rng200.c | 37 ++++++++++++---------------
>  1 file changed, 17 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
> index e106ce3c0146..3367b26085e8 100644
> --- a/drivers/char/hw_random/iproc-rng200.c
> +++ b/drivers/char/hw_random/iproc-rng200.c
> @@ -53,15 +53,26 @@ struct iproc_rng200_dev {
>  
>  #define to_rng_priv(rng)	container_of(rng, struct iproc_rng200_dev, rng)
>  
> -static void iproc_rng200_restart(void __iomem *rng_base)
> +static void iproc_rng200_enable(void __iomem *rng_base, bool enable)

I would prefer naming the function iproc_rng200_enable_set() to indicate
that it sets the enable to the parameter value, this is just personal
taste, you may discard it.

>  {
>  	uint32_t val;

Since you are refactoring this into a new function, do you mind changing
the variable to u32 to match the kernel code? With that fixed:

Acked-by: Florian Fainelli <f.fainelli@gmail.com>

Thanks!
-- 
Florian

Re: [PATCH 1/2] hwrng: iproc-rng200: Fix disable of the block.

[Scott Branden]

On 2020-12-14 8:04 a.m., matthias.bgg@kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
>
> When trying to disable the block we bitwise or the control
> register with value zero. This will leave the block always turned on.
> Fix this by setting the corresponding bit to zero.
>
> Fixes: c83d45d5685f ("hwrng: iproc-rng200 - Add Broadcom IPROC RNG driver")
Commit message needs to be re-written.
I don't think this is an actual fix as the ~RNG_CTL_RNG_RBGEN_MASK already zeros the bit.  This is just a code change, which is fine because it makes things clearer
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
> ---
>
>  drivers/char/hw_random/iproc-rng200.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
> index 01583faf9893..e106ce3c0146 100644
> --- a/drivers/char/hw_random/iproc-rng200.c
> +++ b/drivers/char/hw_random/iproc-rng200.c
> @@ -28,7 +28,6 @@
>  #define RNG_CTRL_OFFSET					0x00
>  #define RNG_CTRL_RNG_RBGEN_MASK				0x00001FFF
>  #define RNG_CTRL_RNG_RBGEN_ENABLE			0x00000001
> -#define RNG_CTRL_RNG_RBGEN_DISABLE			0x00000000
>  
>  #define RNG_SOFT_RESET_OFFSET				0x04
>  #define RNG_SOFT_RESET					0x00000001
> @@ -61,7 +60,7 @@ static void iproc_rng200_restart(void __iomem *rng_base)
>  	/* Disable RBG */
>  	val = ioread32(rng_base + RNG_CTRL_OFFSET);
>  	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
This mask will already zero the enable bit.
> -	val |= RNG_CTRL_RNG_RBGEN_DISABLE;
> +	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
>  	iowrite32(val, rng_base + RNG_CTRL_OFFSET);
>  
>  	/* Clear all interrupt status */
> @@ -174,7 +173,7 @@ static void iproc_rng200_cleanup(struct hwrng *rng)
>  	/* Disable RNG hardware */
>  	val = ioread32(priv->base + RNG_CTRL_OFFSET);
>  	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
> -	val |= RNG_CTRL_RNG_RBGEN_DISABLE;
> +	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
>  	iowrite32(val, priv->base + RNG_CTRL_OFFSET);
>  }
>  

Re: [PATCH 2/2] hwrng: iproc-rng200: Move enable/disable in separate function

[Scott Branden]

On 2020-12-14 8:04 a.m., matthias.bgg@kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
>
> We are calling the same code for enable and disable the block in various
> parts of the driver. Put that code into a new function to reduce code
> duplication.
Patch needs to be regenerated after most of PATCH 1 dropped.
>
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
>
> ---
>
>  drivers/char/hw_random/iproc-rng200.c | 37 ++++++++++++---------------
>  1 file changed, 17 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
> index e106ce3c0146..3367b26085e8 100644
> --- a/drivers/char/hw_random/iproc-rng200.c
> +++ b/drivers/char/hw_random/iproc-rng200.c
> @@ -53,15 +53,26 @@ struct iproc_rng200_dev {
>  
>  #define to_rng_priv(rng)	container_of(rng, struct iproc_rng200_dev, rng)
>  
> -static void iproc_rng200_restart(void __iomem *rng_base)
> +static void iproc_rng200_enable(void __iomem *rng_base, bool enable)
>  {
>  	uint32_t val;
>  
> -	/* Disable RBG */
>  	val = ioread32(rng_base + RNG_CTRL_OFFSET);
>  	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
> -	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
> +
> +	if (enable)
> +		val |= RNG_CTRL_RNG_RBGEN_ENABLE;
> +	else
> +		val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
> +
>  	iowrite32(val, rng_base + RNG_CTRL_OFFSET);
> +}
> +
> +static void iproc_rng200_restart(void __iomem *rng_base)
> +{
> +	uint32_t val;
> +
> +	iproc_rng200_enable(rng_base, false);
>  
>  	/* Clear all interrupt status */
>  	iowrite32(0xFFFFFFFFUL, rng_base + RNG_INT_STATUS_OFFSET);
> @@ -83,11 +94,7 @@ static void iproc_rng200_restart(void __iomem *rng_base)
>  	val &= ~RBG_SOFT_RESET;
>  	iowrite32(val, rng_base + RBG_SOFT_RESET_OFFSET);
>  
> -	/* Enable RBG */
> -	val = ioread32(rng_base + RNG_CTRL_OFFSET);
> -	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
> -	val |= RNG_CTRL_RNG_RBGEN_ENABLE;
> -	iowrite32(val, rng_base + RNG_CTRL_OFFSET);
> +	iproc_rng200_enable(rng_base, true);
>  }
>  
>  static int iproc_rng200_read(struct hwrng *rng, void *buf, size_t max,
> @@ -154,13 +161,8 @@ static int iproc_rng200_read(struct hwrng *rng, void *buf, size_t max,
>  static int iproc_rng200_init(struct hwrng *rng)
>  {
>  	struct iproc_rng200_dev *priv = to_rng_priv(rng);
> -	uint32_t val;
>  
> -	/* Setup RNG. */
> -	val = ioread32(priv->base + RNG_CTRL_OFFSET);
> -	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
> -	val |= RNG_CTRL_RNG_RBGEN_ENABLE;
> -	iowrite32(val, priv->base + RNG_CTRL_OFFSET);
> +	iproc_rng200_enable(priv->base, true);
>  
>  	return 0;
>  }
> @@ -168,13 +170,8 @@ static int iproc_rng200_init(struct hwrng *rng)
>  static void iproc_rng200_cleanup(struct hwrng *rng)
>  {
>  	struct iproc_rng200_dev *priv = to_rng_priv(rng);
> -	uint32_t val;
>  
> -	/* Disable RNG hardware */
> -	val = ioread32(priv->base + RNG_CTRL_OFFSET);
> -	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
> -	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
> -	iowrite32(val, priv->base + RNG_CTRL_OFFSET);
> +	iproc_rng200_enable(priv->base, false);
>  }
>  
>  static int iproc_rng200_probe(struct platform_device *pdev)

Re: [PATCH 1/2] hwrng: iproc-rng200: Fix disable of the block.

[Matthias Brugger]

On 14/12/2020 18:45, Scott Branden wrote:
> 
> 
> On 2020-12-14 8:04 a.m., matthias.bgg@kernel.org wrote:
>> From: Matthias Brugger <mbrugger@suse.com>
>>
>> When trying to disable the block we bitwise or the control
>> register with value zero. This will leave the block always turned on.
>> Fix this by setting the corresponding bit to zero.
>>
>> Fixes: c83d45d5685f ("hwrng: iproc-rng200 - Add Broadcom IPROC RNG driver")
> Commit message needs to be re-written.
> I don't think this is an actual fix as the ~RNG_CTL_RNG_RBGEN_MASK already zeros the bit.  This is just a code change, which is fine because it makes things clearer

Right, I'll reword it.

>> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
>> ---
>>
>>  drivers/char/hw_random/iproc-rng200.c | 5 ++---
>>  1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
>> index 01583faf9893..e106ce3c0146 100644
>> --- a/drivers/char/hw_random/iproc-rng200.c
>> +++ b/drivers/char/hw_random/iproc-rng200.c
>> @@ -28,7 +28,6 @@
>>  #define RNG_CTRL_OFFSET					0x00
>>  #define RNG_CTRL_RNG_RBGEN_MASK				0x00001FFF
>>  #define RNG_CTRL_RNG_RBGEN_ENABLE			0x00000001
>> -#define RNG_CTRL_RNG_RBGEN_DISABLE			0x00000000
>>  
>>  #define RNG_SOFT_RESET_OFFSET				0x04
>>  #define RNG_SOFT_RESET					0x00000001
>> @@ -61,7 +60,7 @@ static void iproc_rng200_restart(void __iomem *rng_base)
>>  	/* Disable RBG */
>>  	val = ioread32(rng_base + RNG_CTRL_OFFSET);
>>  	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
> This mask will already zero the enable bit.
>> -	val |= RNG_CTRL_RNG_RBGEN_DISABLE;
>> +	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;

Correct, so no need for this extra line. I'll delete it.

>>  	iowrite32(val, rng_base + RNG_CTRL_OFFSET);
>>  
>>  	/* Clear all interrupt status */
>> @@ -174,7 +173,7 @@ static void iproc_rng200_cleanup(struct hwrng *rng)
>>  	/* Disable RNG hardware */
>>  	val = ioread32(priv->base + RNG_CTRL_OFFSET);
>>  	val &= ~RNG_CTRL_RNG_RBGEN_MASK;
>> -	val |= RNG_CTRL_RNG_RBGEN_DISABLE;
>> +	val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
>>  	iowrite32(val, priv->base + RNG_CTRL_OFFSET);
>>  }
>>  
>