diff mbox series

iommu: rockchip: fix building without CONFIG_OF

Message ID 20180404102401.3634085-1-arnd@arndb.de
State New
Headers show
Series iommu: rockchip: fix building without CONFIG_OF | expand

Commit Message

Arnd Bergmann April 4, 2018, 10:23 a.m. UTC 
We get a build error when compiling the iommu driver without CONFIG_OF:

drivers/iommu/rockchip-iommu.c: In function 'rk_iommu_of_xlate':
drivers/iommu/rockchip-iommu.c:1101:2: error: implicit declaration of function 'of_dev_put'; did you mean 'of_node_put'? [-Werror=implicit-function-declaration]

This replaces the of_dev_put() with the equivalent platform_device_put(),
and adds an error check for of_find_device_by_node() returning NULL,
which seems to be appropriate here given that we pass the device into
platform_get_drvdata() next, and that of_find_device_by_node() might
theoretically return a NULL pointer.

Fixes: 5fd577c3eac3 ("iommu/rockchip: Use OF_IOMMU to attach devices automatically")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
This warning appears to only have been introduced in linux-next after
the merge window opened.
---
 drivers/iommu/rockchip-iommu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

-- 
2.9.0

Comments

Jeffy Chen April 4, 2018, 11:04 a.m. UTC | #1 
Hi Amd,

Thanks for your patch.

On 04/04/2018 06:23 PM, Arnd Bergmann wrote:
> We get a build error when compiling the iommu driver without CONFIG_OF:

>

> drivers/iommu/rockchip-iommu.c: In function 'rk_iommu_of_xlate':

> drivers/iommu/rockchip-iommu.c:1101:2: error: implicit declaration of function 'of_dev_put'; did you mean 'of_node_put'? [-Werror=implicit-function-declaration]

>

oops, didn't notice that.

and checking other iommu drivers which call of_find_device_by_node() 
too, seems they didn't put() it? maybe we should fix them too

> This replaces the of_dev_put() with the equivalent platform_device_put(),

> and adds an error check for of_find_device_by_node() returning NULL,

> which seems to be appropriate here given that we pass the device into

> platform_get_drvdata() next, and that of_find_device_by_node() might

> theoretically return a NULL pointer.

hmm, i thought the of_iommu_xlate() checked that before calling us:


static int of_iommu_xlate(struct device *dev,
               struct of_phandle_args *iommu_spec)
{
...
     if ((ops && !ops->of_xlate) ||
         !of_device_is_available(iommu_spec->np) ||
         (!ops && !of_iommu_driver_present(iommu_spec->np)))
         return NO_IOMMU;
...
     return ops->of_xlate(dev, iommu_spec);


but it's better to check it ourself :)


>

> Fixes: 5fd577c3eac3 ("iommu/rockchip: Use OF_IOMMU to attach devices automatically")

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

> This warning appears to only have been introduced in linux-next after

> the merge window opened.

> ---

>   drivers/iommu/rockchip-iommu.c | 6 +++++-

>   1 file changed, 5 insertions(+), 1 deletion(-)

>

> diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c

> index 5fc8656c60f9..fe9c9cc1a9d4 100644

> --- a/drivers/iommu/rockchip-iommu.c

> +++ b/drivers/iommu/rockchip-iommu.c

> @@ -1094,11 +1094,15 @@ static int rk_iommu_of_xlate(struct device *dev,

>   		return -ENOMEM;

>

>   	iommu_dev = of_find_device_by_node(args->np);

> +	if (!iommu_dev) {

> +		kfree(data);

> +		return -ENODEV;

> +	}

>

>   	data->iommu = platform_get_drvdata(iommu_dev);

>   	dev->archdata.iommu = data;

>

> -	of_dev_put(iommu_dev);

> +	platform_device_put(iommu_dev);

>

>   	return 0;

>   }

>
Robin Murphy April 4, 2018, 11:12 a.m. UTC | #2 
Hi Arnd,

On 04/04/18 11:23, Arnd Bergmann wrote:
> We get a build error when compiling the iommu driver without CONFIG_OF:

> 

> drivers/iommu/rockchip-iommu.c: In function 'rk_iommu_of_xlate':

> drivers/iommu/rockchip-iommu.c:1101:2: error: implicit declaration of function 'of_dev_put'; did you mean 'of_node_put'? [-Werror=implicit-function-declaration]

> 

> This replaces the of_dev_put() with the equivalent platform_device_put(),

> and adds an error check for of_find_device_by_node() returning NULL,

> which seems to be appropriate here given that we pass the device into

> platform_get_drvdata() next, and that of_find_device_by_node() might

> theoretically return a NULL pointer.

> 

> Fixes: 5fd577c3eac3 ("iommu/rockchip: Use OF_IOMMU to attach devices automatically")

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

> This warning appears to only have been introduced in linux-next after

> the merge window opened.

> ---

>   drivers/iommu/rockchip-iommu.c | 6 +++++-

>   1 file changed, 5 insertions(+), 1 deletion(-)

> 

> diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c

> index 5fc8656c60f9..fe9c9cc1a9d4 100644

> --- a/drivers/iommu/rockchip-iommu.c

> +++ b/drivers/iommu/rockchip-iommu.c

> @@ -1094,11 +1094,15 @@ static int rk_iommu_of_xlate(struct device *dev,

>   		return -ENOMEM;

>   

>   	iommu_dev = of_find_device_by_node(args->np);

> +	if (!iommu_dev) {


Actually, though the logic is perhaps a bit subtle, this cannot 
reasonably happen - .of_xlate is only called via a set of iommu_ops 
associated with the IOMMU node (args->np here); those ops are only 
registered for the given node at the end of rk_iommu_probe(), by which 
point the IOMMU device exists and is otherwise successfully probed, so 
the platform bus lookup should never be able to fail.

> +		kfree(data);

> +		return -ENODEV;

> +	}

>   

>   	data->iommu = platform_get_drvdata(iommu_dev);

>   	dev->archdata.iommu = data;

>   

> -	of_dev_put(iommu_dev);

> +	platform_device_put(iommu_dev);


This bit looks reasonable, thanks for the fix.

Robin.

>   

>   	return 0;

>   }

>
Joerg Roedel May 3, 2018, 12:46 p.m. UTC | #3 
On Wed, Apr 04, 2018 at 12:23:53PM +0200, Arnd Bergmann wrote:
> We get a build error when compiling the iommu driver without CONFIG_OF:

> 

> drivers/iommu/rockchip-iommu.c: In function 'rk_iommu_of_xlate':

> drivers/iommu/rockchip-iommu.c:1101:2: error: implicit declaration of function 'of_dev_put'; did you mean 'of_node_put'? [-Werror=implicit-function-declaration]

> 

> This replaces the of_dev_put() with the equivalent platform_device_put(),

> and adds an error check for of_find_device_by_node() returning NULL,

> which seems to be appropriate here given that we pass the device into

> platform_get_drvdata() next, and that of_find_device_by_node() might

> theoretically return a NULL pointer.

> 

> Fixes: 5fd577c3eac3 ("iommu/rockchip: Use OF_IOMMU to attach devices automatically")

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

> This warning appears to only have been introduced in linux-next after

> the merge window opened.

> ---

>  drivers/iommu/rockchip-iommu.c | 6 +++++-

>  1 file changed, 5 insertions(+), 1 deletion(-)


Changed patch according to Robins comments and applied it, thanks.
diff mbox series

Patch

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 5fc8656c60f9..fe9c9cc1a9d4 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -1094,11 +1094,15 @@  static int rk_iommu_of_xlate(struct device *dev,
 		return -ENOMEM;
 
 	iommu_dev = of_find_device_by_node(args->np);
+	if (!iommu_dev) {
+		kfree(data);
+		return -ENODEV;
+	}
 
 	data->iommu = platform_get_drvdata(iommu_dev);
 	dev->archdata.iommu = data;
 
-	of_dev_put(iommu_dev);
+	platform_device_put(iommu_dev);
 
 	return 0;
 }