Re: [PATCH v2 5/5] iommu/arm-smmu: Convert to domain_alloc_paging()

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Dec 13, 2023 at 01:27:01PM +0000, Will Deacon wrote:
> On Tue, Dec 12, 2023 at 02:10:23PM +0000, Will Deacon wrote:
> > On Tue, Dec 12, 2023 at 10:03:07AM -0400, Jason Gunthorpe wrote:
> > > On Tue, Dec 12, 2023 at 01:26:51PM +0000, Will Deacon wrote:
> > > > Why do we need to handle the 'dev && !cfg' case here, instead g
> > > > returning NULL?
> > > 
> > > dev && !cfg is impossible these days, so we can shuffle the if and
> > > then just crash on that case like the other drivers do.
> > 
> > Thanks, that would simplify it a little.
> 
> Folded in the diff below.
> 
> Will
> 
> --->8
> 
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> index 536e47e3a65a..b0a6b367d8a2 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> @@ -861,7 +861,6 @@ static void arm_smmu_destroy_domain_context(struct arm_smmu_domain *smmu_domain)
>  
>  static struct iommu_domain *arm_smmu_domain_alloc_paging(struct device *dev)
>  {
> -	struct arm_smmu_master_cfg *cfg = NULL;
>  	struct arm_smmu_domain *smmu_domain;
>  
>  	/*
> @@ -876,13 +875,10 @@ static struct iommu_domain *arm_smmu_domain_alloc_paging(struct device *dev)
>  	mutex_init(&smmu_domain->init_mutex);
>  	spin_lock_init(&smmu_domain->cb_lock);
>  
> -	if (dev)
> -		cfg = dev_iommu_priv_get(dev);
> -	if (cfg) {
> -		int ret;
> +	if (dev) {
> +		struct arm_smmu_master_cfg *cfg = dev_iommu_priv_get(dev);
>  
> -		ret = arm_smmu_init_domain_context(smmu_domain, cfg->smmu, dev);
> -		if (ret) {
> +		if (arm_smmu_init_domain_context(smmu_domain, cfg->smmu, dev)) {
>  			kfree(smmu_domain);
>  			return NULL;
>  		}

Looks good, thanks

Jason