Re: [PATCH v3 5/7] iommu: Allow io_pgtable_tlb ops optional

[Robin Murphy]

On 2020-12-16 10:36, Yong Wu wrote:
> This patch allows io_pgtable_tlb ops could be null since the IOMMU drivers
> may use the tlb ops from iommu framework.

There's not much in it, but I guess this does make more sense overall 
than just making .tlb_flush_all optional and drivers having to provide a 
full set of NULL callbacks.

Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>

> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> ---
>   include/linux/io-pgtable.h | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
> index adde9e49be08..c81796814afa 100644
> --- a/include/linux/io-pgtable.h
> +++ b/include/linux/io-pgtable.h
> @@ -206,14 +206,16 @@ struct io_pgtable {
>   
>   static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
>   {
> -	iop->cfg.tlb->tlb_flush_all(iop->cookie);
> +	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_all)
> +		iop->cfg.tlb->tlb_flush_all(iop->cookie);
>   }
>   
>   static inline void
>   io_pgtable_tlb_flush_walk(struct io_pgtable *iop, unsigned long iova,
>   			  size_t size, size_t granule)
>   {
> -	iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
> +	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_walk)
> +		iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
>   }
>   
>   static inline void
> @@ -221,7 +223,7 @@ io_pgtable_tlb_add_page(struct io_pgtable *iop,
>   			struct iommu_iotlb_gather * gather, unsigned long iova,
>   			size_t granule)
>   {
> -	if (iop->cfg.tlb->tlb_add_page)
> +	if (iop->cfg.tlb && iop->cfg.tlb->tlb_add_page)
>   		iop->cfg.tlb->tlb_add_page(gather, iova, granule, iop->cookie);
>   }
>