Re: [PATCH] iommu: arm-smmu: avoid build warning

[Will Deacon <will.deacon@arm.com>]

On Fri, Jan 30, 2015 at 09:55:55PM +0000, Arnd Bergmann wrote:
> ARM allmodconfig gained a new warning when dma_addr_t is 32-bit wide:
> 
> drivers/iommu/arm-smmu.c: In function 'arm_smmu_iova_to_phys_hard':
> drivers/iommu/arm-smmu.c:1255:3: warning: right shift count >= width of type
> 
> This changes the calculation so that the effective type is always
> 64-bit.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: 859a732e4f713 ("iommu/arm-smmu: add support for iova_to_phys through ATS1PR")
> 
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 1d6d43bb3395..fc13dd56953e 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1252,7 +1252,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
>  	} else {
>  		u32 reg = iova & ~0xfff;
>  		writel_relaxed(reg, cb_base + ARM_SMMU_CB_ATS1PR_LO);
> -		reg = (iova & ~0xfff) >> 32;
> +		reg = ((u64)iova & ~0xfff) >> 32;
>  		writel_relaxed(reg, cb_base + ARM_SMMU_CB_ATS1PR_HI);
>  	}

Thanks, Arnd.

Acked-by: Will Deacon <will.deacon@arm.com>

Joerg, could you pick this one up directly please? I don't have any other
ARM SMMU fixes queued at the moment.

Will