Re: [PATCH v3 07/11] lib: bitmap: provide devm_bitmap_alloc() and devm_bitmap_zalloc()

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

On Tue, Mar 09, 2021 at 09:59:17PM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> 
> Provide managed variants of bitmap_alloc() and bitmap_zalloc().
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
>  include/linux/bitmap.h |  8 ++++++++
>  lib/bitmap.c           | 33 +++++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+)
> 
> diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
> index 3282db97e06c..73d039476fa4 100644
> --- a/include/linux/bitmap.h
> +++ b/include/linux/bitmap.h
> @@ -9,6 +9,8 @@
>  #include <linux/string.h>
>  #include <linux/types.h>
>  
> +struct device;
> +
>  /*
>   * bitmaps provide bit arrays that consume one or more unsigned
>   * longs.  The bitmap interface and available operations are listed
> @@ -122,6 +124,12 @@ unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
>  unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
>  void bitmap_free(const unsigned long *bitmap);
>  
> +/* Managed variants of the above. */
> +unsigned long *devm_bitmap_alloc(struct device *dev,
> +				 unsigned int nbits, gfp_t flags);
> +unsigned long *devm_bitmap_zalloc(struct device *dev,
> +				  unsigned int nbits, gfp_t flags);
> +
>  /*
>   * lib/bitmap.c provides these functions:
>   */
> diff --git a/lib/bitmap.c b/lib/bitmap.c
> index 78f70d9007ad..b4fd7fd084c6 100644
> --- a/lib/bitmap.c
> +++ b/lib/bitmap.c
> @@ -8,6 +8,7 @@
>  #include <linux/bitops.h>
>  #include <linux/bug.h>
>  #include <linux/ctype.h>
> +#include <linux/device.h>
>  #include <linux/errno.h>
>  #include <linux/export.h>
>  #include <linux/kernel.h>
> @@ -1263,6 +1264,38 @@ void bitmap_free(const unsigned long *bitmap)
>  }
>  EXPORT_SYMBOL(bitmap_free);
>  
> +static void devm_bitmap_free(void *data)
> +{
> +	unsigned long *bitmap = data;
> +
> +	bitmap_free(bitmap);
> +}
> +
> +unsigned long *devm_bitmap_alloc(struct device *dev,
> +				 unsigned int nbits, gfp_t flags)
> +{
> +	unsigned long *bitmap;
> +	int ret;
> +
> +	bitmap = bitmap_alloc(nbits, flags);
> +	if (!bitmap)
> +		return NULL;
> +
> +	ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap);
> +	if (ret)
> +		return NULL;
> +
> +	return bitmap;
> +}
> +EXPORT_SYMBOL(devm_bitmap_alloc);
> +
> +unsigned long *devm_bitmap_zalloc(struct device *dev,
> +				  unsigned int nbits, gfp_t flags)
> +{
> +	return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO);
> +}
> +EXPORT_SYMBOL(devm_bitmap_zalloc);

devm_* functions have been traditionally exported with
EXPORT_SYMBOL_GPL() due to the use of a struct device *.  Perhaps do
that here as well?

thanks,

greg k-h