Re: [Patch v2 2/9] iommu/amd: Detect pre enabled translation

[Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>]

On Fri, Nov 06, 2015 at 08:10:44PM +0800, Baoquan He wrote:
> Add functions to check whether translation is already enabled in IOMMU.
> 
> Signed-off-by: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/iommu/amd_iommu_init.c  | 26 ++++++++++++++++++++++++++
>  drivers/iommu/amd_iommu_proto.h |  4 ++++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
> index 1dcd8e3..6ef86b1 100644
> --- a/drivers/iommu/amd_iommu_init.c
> +++ b/drivers/iommu/amd_iommu_init.c
> @@ -229,6 +229,27 @@ static int amd_iommu_enable_interrupts(void);
>  static int __init iommu_go_to_state(enum iommu_init_state state);
>  static void init_device_table_dma(void);
>  
> +static u8 g_pre_enabled;

Better use bool here ...

> +
> +bool translation_pre_enabled(void)

... since this function returns bool anyway, and ...

> +{
> +        return !!g_pre_enabled;

... use save the ugly !! operators.