[PATCH kernel v3 15/22] powerpc/powernv: Reference iommu_table while it is linked to a group

[David Gibson]

On Tue, Nov 13, 2018 at 07:28:16PM +1100, Alexey Kardashevskiy wrote:
> The iommu_table pointer stored in iommu_table_group may get stale
> by accident, this adds referencing and removes a redundant comment
> about this.
> 
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>

Reviewed-by: David Gibson <david at gibson.dropbear.id.au>

> ---
>  arch/powerpc/platforms/powernv/pci-ioda-tce.c | 3 ++-
>  arch/powerpc/platforms/powernv/pci-ioda.c     | 4 ----
>  2 files changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda-tce.c b/arch/powerpc/platforms/powernv/pci-ioda-tce.c
> index 7639b21..697449a 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda-tce.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda-tce.c
> @@ -368,6 +368,7 @@ void pnv_pci_unlink_table_and_group(struct iommu_table *tbl,
>  	found = false;
>  	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>  		if (table_group->tables[i] == tbl) {
> +			iommu_tce_table_put(tbl);
>  			table_group->tables[i] = NULL;
>  			found = true;
>  			break;
> @@ -393,7 +394,7 @@ long pnv_pci_link_table_and_group(int node, int num,
>  	tgl->table_group = table_group;
>  	list_add_rcu(&tgl->next, &tbl->it_group_list);
>  
> -	table_group->tables[num] = tbl;
> +	table_group->tables[num] = iommu_tce_table_get(tbl);
>  
>  	return 0;
>  }
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 7f4904a..7caf373 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -2716,10 +2716,6 @@ static long pnv_pci_ioda2_npu_unset_window(
>  
>  static void pnv_ioda2_npu_take_ownership(struct iommu_table_group *table_group)
>  {
> -	/*
> -	 * Detach NPU first as pnv_ioda2_take_ownership() will destroy
> -	 * the iommu_table if 32bit DMA is enabled.
> -	 */
>  	pnv_npu_take_ownership(gpe_table_group_to_npe(table_group));
>  	pnv_ioda2_take_ownership(table_group);
>  }

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
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