RE: [PATCH v2 1/3] iommu/vt-d: Remove duplicate identity domain flag

[Tian, Kevin]

> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Sunday, September 26, 2021 7:46 PM
> 
> The iommu_domain data structure already has the "type" field to keep the
> type of a domain. It's unnecessary to have the
> DOMAIN_FLAG_STATIC_IDENTITY
> flag in the vt-d implementation. This cleans it up with no functionality
> change.
> 
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>

> ---
>  include/linux/intel-iommu.h | 3 ---
>  drivers/iommu/intel/iommu.c | 9 ++++-----
>  2 files changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> index 4bff70c26416..c24bdf5a9285 100644
> --- a/include/linux/intel-iommu.h
> +++ b/include/linux/intel-iommu.h
> @@ -517,9 +517,6 @@ struct context_entry {
>  	u64 hi;
>  };
> 
> -/* si_domain contains mulitple devices */
> -#define DOMAIN_FLAG_STATIC_IDENTITY		BIT(0)
> -
>  /*
>   * When VT-d works in the scalable mode, it allows DMA translation to
>   * happen through either first level or second level page table. This
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index b0076f54f5f4..dc2030d014e0 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -528,7 +528,7 @@ static inline void free_devinfo_mem(void *vaddr)
> 
>  static inline int domain_type_is_si(struct dmar_domain *domain)
>  {
> -	return domain->flags & DOMAIN_FLAG_STATIC_IDENTITY;
> +	return domain->domain.type == IOMMU_DOMAIN_IDENTITY;
>  }
> 
>  static inline bool domain_use_first_level(struct dmar_domain *domain)
> @@ -1996,7 +1996,7 @@ static bool first_level_by_default(void)
>  	return scalable_mode_support() && intel_cap_flts_sanity();
>  }
> 
> -static struct dmar_domain *alloc_domain(int flags)
> +static struct dmar_domain *alloc_domain(unsigned int type)
>  {
>  	struct dmar_domain *domain;
> 
> @@ -2006,7 +2006,6 @@ static struct dmar_domain *alloc_domain(int flags)
> 
>  	memset(domain, 0, sizeof(*domain));
>  	domain->nid = NUMA_NO_NODE;
> -	domain->flags = flags;
>  	if (first_level_by_default())
>  		domain->flags |= DOMAIN_FLAG_USE_FIRST_LEVEL;
>  	domain->has_iotlb_device = false;
> @@ -2830,7 +2829,7 @@ static int __init si_domain_init(int hw)
>  	struct device *dev;
>  	int i, nid, ret;
> 
> -	si_domain = alloc_domain(DOMAIN_FLAG_STATIC_IDENTITY);
> +	si_domain = alloc_domain(IOMMU_DOMAIN_IDENTITY);
>  	if (!si_domain)
>  		return -EFAULT;
> 
> @@ -4639,7 +4638,7 @@ static struct iommu_domain
> *intel_iommu_domain_alloc(unsigned type)
>  	case IOMMU_DOMAIN_DMA:
>  	case IOMMU_DOMAIN_DMA_FQ:
>  	case IOMMU_DOMAIN_UNMANAGED:
> -		dmar_domain = alloc_domain(0);
> +		dmar_domain = alloc_domain(type);
>  		if (!dmar_domain) {
>  			pr_err("Can't allocate dmar_domain\n");
>  			return NULL;
> --
> 2.25.1