Re: [PATCH v4 13/16] iommu/amd: Refactor GCR3 table helper functions

[Jason Gunthorpe <jgg@ziepe.ca>]

On Tue, Dec 12, 2023 at 08:52:21AM +0000, Vasant Hegde wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> 
> To use the new per-device struct gcr3_tbl_info. Use GFP_KERNEL flag
> instead of GFP_ATOMIC for GCR3 table allocation. Also modify
> set_dte_entry() to use new per device GCR3 table.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
> Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
> ---
>  drivers/iommu/amd/iommu.c | 55 +++++++++++++++++++++++----------------
>  1 file changed, 33 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
> index 584608b98f26..7e5f32817931 100644
> --- a/drivers/iommu/amd/iommu.c
> +++ b/drivers/iommu/amd/iommu.c
> @@ -79,6 +79,9 @@ struct kmem_cache *amd_iommu_irq_cache;
>  
>  static void detach_device(struct device *dev);
>  
> +static void set_dte_entry(struct amd_iommu *iommu,
> +			  struct iommu_dev_data *dev_data);
> +
>  /****************************************************************************
>   *
>   * Helper functions
> @@ -1716,16 +1719,21 @@ static void free_gcr3_tbl_level2(u64 *tbl)
>  	}
>  }
>  
> -static void free_gcr3_table(struct protection_domain *domain)
> +static void free_gcr3_table(struct iommu_dev_data *dev_data)
>  {

Pass in struct gcr3_tbl_info not dev_data

> -/* Note: This function expects iommu_domain->lock to be held prior calling the function. */
> -static int setup_gcr3_table(struct protection_domain *domain, int pasids)
> +static int setup_gcr3_table(struct iommu_dev_data *dev_data, int pasids)
>  {
> +	struct gcr3_tbl_info *gcr3_info = &dev_data->gcr3_info;
>  	int levels = get_gcr3_levels(pasids);

Pass in struct gcr3_tbl_info not dev_data

I don't think it is worth re-doing at this point - but I probably
would have tried to structure this series as creating the struct
gcr3_tbl_info and migrating the protection_domain to use it, then
streamlined the APIs to have a clean gcr3_tbl_info layer, finally
adding a gcr3_tbl_info to the iommu_dev_data and using it when
appropriate.

Jason