[PATCH 1/7] powerpc/powernv/npu: Clean up compound table group initialisation

[Alexey Kardashevskiy]

On 06/04/2020 13:07, Oliver O'Halloran wrote:
> Re-work the control flow a bit so what's going on is a little clearer.
> This also ensures the table_group is only initialised once in the P9
> case. This shouldn't be a functional change since all the GPU PCI
> devices should have the same table_group configuration, but it does
> look strange.
> 
> Cc: Alexey Kardashevskiy <aik at ozlabs.ru>
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>


Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>



> ---
>  arch/powerpc/platforms/powernv/npu-dma.c | 46 +++++++++++-------------
>  1 file changed, 21 insertions(+), 25 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
> index b95b9e3c4c98..de617549c9a3 100644
> --- a/arch/powerpc/platforms/powernv/npu-dma.c
> +++ b/arch/powerpc/platforms/powernv/npu-dma.c
> @@ -427,7 +427,7 @@ static void pnv_comp_attach_table_group(struct npu_comp *npucomp,
>  
>  struct iommu_table_group *pnv_try_setup_npu_table_group(struct pnv_ioda_pe *pe)
>  {
> -	struct iommu_table_group *table_group;
> +	struct iommu_table_group *compound_group;
>  	struct npu_comp *npucomp;
>  	struct pci_dev *gpdev = NULL;
>  	struct pci_controller *hose;
> @@ -446,36 +446,32 @@ struct iommu_table_group *pnv_try_setup_npu_table_group(struct pnv_ioda_pe *pe)
>  	hose = pci_bus_to_host(npdev->bus);
>  
>  	if (hose->npu) {
> -		table_group = &hose->npu->npucomp.table_group;
> -
> -		if (!table_group->group) {
> -			table_group->ops = &pnv_npu_peers_ops;
> -			iommu_register_group(table_group,
> -					hose->global_number,
> -					pe->pe_number);
> -		}
> +		/* P9 case: compound group is per-NPU (all gpus, all links) */
> +		npucomp = &hose->npu->npucomp;
>  	} else {
> -		/* Create a group for 1 GPU and attached NPUs for POWER8 */
> -		pe->npucomp = kzalloc(sizeof(*pe->npucomp), GFP_KERNEL);
> -		table_group = &pe->npucomp->table_group;
> -		table_group->ops = &pnv_npu_peers_ops;
> -		iommu_register_group(table_group, hose->global_number,
> -				pe->pe_number);
> +		/* P8 case: Compound group is per-GPU (1 gpu, 2 links) */
> +		npucomp = pe->npucomp = kzalloc(sizeof(*npucomp), GFP_KERNEL);
>  	}
>  
> -	/* Steal capabilities from a GPU PE */
> -	table_group->max_dynamic_windows_supported =
> -		pe->table_group.max_dynamic_windows_supported;
> -	table_group->tce32_start = pe->table_group.tce32_start;
> -	table_group->tce32_size = pe->table_group.tce32_size;
> -	table_group->max_levels = pe->table_group.max_levels;
> -	if (!table_group->pgsizes)
> -		table_group->pgsizes = pe->table_group.pgsizes;
> +	compound_group = &npucomp->table_group;
> +	if (!compound_group->group) {
> +		compound_group->ops = &pnv_npu_peers_ops;
> +		iommu_register_group(compound_group, hose->global_number,
> +				pe->pe_number);
> +
> +		/* Steal capabilities from a GPU PE */
> +		compound_group->max_dynamic_windows_supported =
> +			pe->table_group.max_dynamic_windows_supported;
> +		compound_group->tce32_start = pe->table_group.tce32_start;
> +		compound_group->tce32_size = pe->table_group.tce32_size;
> +		compound_group->max_levels = pe->table_group.max_levels;
> +		if (!compound_group->pgsizes)
> +			compound_group->pgsizes = pe->table_group.pgsizes;
> +	}
>  
> -	npucomp = container_of(table_group, struct npu_comp, table_group);
>  	pnv_comp_attach_table_group(npucomp, pe);
>  
> -	return table_group;
> +	return compound_group;
>  }
>  
>  struct iommu_table_group *pnv_npu_compound_attach(struct pnv_ioda_pe *pe)
> 

-- 
Alexey