Subject: Re: linux-next: build failure after merge of the iommu tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 13 Oct 2020 18:31:07 +1100

Hi all,

On Mon, 21 Sep 2020 14:09:01 +1000 Stephen Rothwell <[email-masked]> wrote:
>
> After merging the iommu tree, today's linux-next build (arm
> multi_v7_defconfig) failed like this:
> 
> drivers/gpu/drm/msm/msm_iommu.c: In function 'msm_iommu_pagetable_unmap':
> drivers/gpu/drm/msm/msm_iommu.c:46:2: error: implicit declaration of function 'iommu_flush_tlb_all'; did you mean 'iommu_flush_iotlb_all'? [-Werror=implicit-function-declaration]
>    46 |  iommu_flush_tlb_all(to_msm_iommu(pagetable->parent)->domain);
>       |  ^~~~~~~~~~~~~~~~~~~
>       |  iommu_flush_iotlb_all
> 
> Caused by commit
> 
>   aae4c8e27bd7 ("iommu: Rename iommu_tlb_* functions to iommu_iotlb_*")
> 
> interacting with commit
> 
>   b145c6e65eb0 ("drm/msm: Add support to create a local pagetable")
> 
> from the drm-msm tree.
> 
> I have applied the following merge fix patch.  Someone will need to tell
> Linus about this fix up when the trees get merged.
> 
> From: Stephen Rothwell <[email-masked]>
> Date: Mon, 21 Sep 2020 14:04:14 +1000
> Subject: [PATCH] merge fix upt for iommu_flush_iotlb_all() rename
> 
> Signed-off-by: Stephen Rothwell <[email-masked]>
> ---
>  drivers/gpu/drm/msm/msm_iommu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> index 3a83ffdb3b90..22ac7c692a81 100644
> --- a/drivers/gpu/drm/msm/msm_iommu.c
> +++ b/drivers/gpu/drm/msm/msm_iommu.c
> @@ -43,7 +43,7 @@ static int msm_iommu_pagetable_unmap(struct msm_mmu *mmu, u64 iova,
>  		size -= 4096;
>  	}
>  
> -	iommu_flush_tlb_all(to_msm_iommu(pagetable->parent)->domain);
> +	iommu_flush_iotlb_all(to_msm_iommu(pagetable->parent)->domain);
>  
>  	return (unmapped == size) ? 0 : -EINVAL;
>  }
> @@ -199,7 +199,7 @@ struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
>  
>  	/*
>  	 * TODO we would like each set of page tables to have a unique ASID
> -	 * to optimize TLB invalidation.  But iommu_flush_tlb_all() will
> +	 * to optimize TLB invalidation.  But iommu_flush_iotlb_all() will
>  	 * end up flushing the ASID used for TTBR1 pagetables, which is not
>  	 * what we want.  So for now just use the same ASID as TTBR1.
>  	 */
> -- 
> 2.28.0

This merge fix up is now needed when the iommu tree and the drm tree are merged.
-- 
Cheers,
Stephen Rothwell