Re: [PATCH] iommu/amd: Fix precedence order in set_dte_passthrough()

[Vasant Hegde <vasant.hegde@amd.com>]

On 5/1/2026 4:58 AM, Weinan Liu wrote:
> Bitwise OR | operator has a higher precedence than the ternary ?:
> operatior. It will be incorrectly evaluated as:
> 
> new->data[1] |= (FIELD_PREP(...) | dev_data->ats_enabled) ? DTE_FLAG_IOTLB : 0;
> 
> Wrap the conditional operation in parentheses to enforce the
> correct evaluation order.
> 
> Fixes: 93eee2a49c1b ("iommu/amd: Refactor logic to program the host page table in DTE")
> Signed-off-by: Weinan Liu <wnliu@google.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>

-Vasant

> ---
>  drivers/iommu/amd/iommu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
> index 01171361f9bc..ccffbecb15c2 100644
> --- a/drivers/iommu/amd/iommu.c
> +++ b/drivers/iommu/amd/iommu.c
> @@ -2149,7 +2149,8 @@ static void set_dte_passthrough(struct iommu_dev_data *dev_data,
>  	new->data[0] |= DTE_FLAG_TV | DTE_FLAG_IR | DTE_FLAG_IW;
>  
>  	new->data[1] |= FIELD_PREP(DTE_DOMID_MASK, domain->id) |
> -			(dev_data->ats_enabled) ? DTE_FLAG_IOTLB : 0;
> +			(dev_data->ats_enabled ? DTE_FLAG_IOTLB : 0);
> +
>  }
>  
>  static void set_dte_entry(struct amd_iommu *iommu,