[RFC PATCH v4 12/15] iommu/io-pgtable-arm-v7s: Implement arm_v7s_unmap_pages()

[Will Deacon]

On Wed, Apr 07, 2021 at 09:52:38PM -0700, Isaac J. Manjarres wrote:
> Implement the unmap_pages() callback for the ARM v7s io-pgtable
> format.
> 
> Signed-off-by: Isaac J. Manjarres <isaacm at codeaurora.org>
> ---
>  drivers/iommu/io-pgtable-arm-v7s.c | 23 ++++++++++++++++++++---
>  1 file changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> index d4004bcf333a..5e203e03c352 100644
> --- a/drivers/iommu/io-pgtable-arm-v7s.c
> +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> @@ -710,15 +710,32 @@ static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *data,
>  	return __arm_v7s_unmap(data, gather, iova, size, lvl + 1, ptep);
>  }
>  
> -static size_t arm_v7s_unmap(struct io_pgtable_ops *ops, unsigned long iova,
> -			    size_t size, struct iommu_iotlb_gather *gather)
> +static size_t arm_v7s_unmap_pages(struct io_pgtable_ops *ops, unsigned long iova,
> +				  size_t pgsize, size_t pgcount,
> +				  struct iommu_iotlb_gather *gather)
>  {
>  	struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
> +	size_t unmapped = 0, ret;
>  
>  	if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias)))
>  		return 0;
>  
> -	return __arm_v7s_unmap(data, gather, iova, size, 1, data->pgd);
> +	while (pgcount--) {
> +		ret = __arm_v7s_unmap(data, gather, iova, pgsize, 1, data->pgd);
> +		if (!ret)
> +			break;
> +
> +		unmapped += pgsize;
> +		iova += pgsize;
> +	}
> +
> +	return unmapped;
> +}

Wait -- don't you need to hook this up somewhere (likewise for ->map_pages)?
How are you testing this?

Will