Re: [PATCH v11 01/11] iommu/arm-smmu-v3: Init the vmid_map ida before the stream table setup

[Mostafa Saleh]

On Mon, Oct 05, 2026 at 12:30:44PM -0700, Nicolin Chen wrote:
> The vmid_map ida is initialized after the stream table setup, along with
> the devres action that destroys it.
> 
> An upcoming change will reserve the crashed kernel's in-use VMIDs in this
> ida, from a kdump kernel's stream table adoption that runs in place of the
> regular setup and returns early.
> 
> Move the ida_init() and its devres registration to the entry of the whole
> function, so that the ida is ready by the time the adoption path runs.
> 
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Tested-by: Breno Leitao <leitao@xxxxxxxxxx>
> Tested-by: Cristian Prundeanu <cpru@xxxxxxxxxx>
> Assisted-by: LLM
> Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>

Reviewed-by: Mostafa Saleh <smostafa@xxxxxxxxxx>

Thanks,
Mostafa

> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 34e916ea339ff..792627e1c790e 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -4842,17 +4842,17 @@ static int arm_smmu_init_strtab(struct arm_smmu_device *smmu)
>  {
>  	int ret;
>  
> +	ida_init(&smmu->vmid_map);
> +	ret = devm_add_action_or_reset(smmu->dev, arm_smmu_destroy_vmid_map,
> +				       &smmu->vmid_map);
> +	if (ret)
> +		return ret;
> +
>  	if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB)
>  		ret = arm_smmu_init_strtab_2lvl(smmu);
>  	else
>  		ret = arm_smmu_init_strtab_linear(smmu);
> -	if (ret)
> -		return ret;
> -
> -	ida_init(&smmu->vmid_map);
> -
> -	return devm_add_action_or_reset(smmu->dev, arm_smmu_destroy_vmid_map,
> -					&smmu->vmid_map);
> +	return ret;
>  }
>  
>  static int arm_smmu_init_structures(struct arm_smmu_device *smmu)
> -- 
> 2.43.0
>