Re: [PATCH v2 0/7] Remove ops.pgsize_bitmap

From: Nicolin Chen <nicolinc@nvidia.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>,
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Subject: Re: [PATCH v2 0/7] Remove ops.pgsize_bitmap
Date: Mon, 9 Jun 2025 15:45:20 -0700	[thread overview]
Message-ID: <aEdkADqw6WGIPAmH@nvidia.com> (raw)
In-Reply-To: <0-v2-68a2e1ba507c+1fb-iommu_rm_ops_pgsize_jgg@nvidia.com>

On Mon, Jun 09, 2025 at 05:41:24PM -0300, Jason Gunthorpe wrote:
> Now that all drivers are using domain_alloc_paging() and dev is never
> NULL, we can have all drivers correctly set domain.pgsize_bitmap during
> their allocation function.
> 
> There are a few oddities that have accumulated here over past changes:
> 
>  - Some drivers always set domain.pgsize_bitmap during their
>    domain_alloc_paging() call but still provide a value in ops. This is dead
>    code, delete it.
> 
>  - Some drivers calculate a system global pgsize_bitmap in the ops, but
>    it is now trivial to use the per-instance value instead. In several
>    cases this is dead code, delete it. This also allows
>    constifying the ops in these drivers as a hardening measure
> 
>  - Some drivers have a fixed pgsize_bitmap, put it next to setting up the
>    geometry in their domain_alloc_paging() functions.
> 
>  - Finally a few drivers still use ops because they have a delayed
>    finalize operation. Set the constant pgsize_bitmap in the
>    domain_alloc_paging().
> 
> Then remove ops.pgsize_bitmap.
> 
> This is based on iommu next, and must go after the virtio
> domain_alloc_paging() conversion.
> 
> v2:
>  - Rebase on v6.16-rc1

Sanity tests with SMMUv3 look good.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>