Subject: Re: [PATCH kernel] powerpc/iommu: Set default DMA offset in dma_dev_setup

From: Gavin Shan <[email-masked]>
Date: Thu, 27 Aug 2015 16:16:35 +1000

On Thu, Aug 27, 2015 at 04:01:16PM +1000, Alexey Kardashevskiy wrote:
>"powerpc/iommu: Cleanup setting of DMA base/offset" expects that
>the default DMA offset is set from pnv_ioda_setup_bus_dma() which
>is correct unless it is SRIOV where the code flow is different - at
>the moment when pnv_ioda_setup_bus_dma() is called, there is no PE for
>the just created VF.
>

The PEs for VFs are ready at the moment. We don't have pci_dev for
VFs actually.

>This adds missing set_dma_offset() to pnv_pci_ioda_dma_dev_setup()
>to cover the case of SRIOV.
>
>Note that we still need set_dma_offset() in pnv_ioda_setup_bus_dma()
>as at the boot time pnv_pci_ioda_dma_dev_setup() is called when no PE
>was created yet, this happens at the PHB fixup stage.
>
>Signed-off-by: Alexey Kardashevskiy <[email-masked]>

Reviewed-by: Gavin Shan <[email-masked]>

Thanks,
Gavin

>---
>
>Makes sense to squash it to "powerpc/iommu: Cleanup setting of DMA base/offset".
>
>
>---
> arch/powerpc/platforms/powernv/pci-ioda.c | 1 +
> 1 file changed, 1 insertion(+)
>
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 2c286b57..af875c1 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -1590,6 +1590,7 @@ static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev
>
> 	pe = &phb->ioda.pe_array[pdn->pe_number];
> 	WARN_ON(get_dma_ops(&pdev->dev) != &dma_iommu_ops);
>+	set_dma_offset(&pdev->dev, pe->tce_bypass_base);
> 	set_iommu_table_base(&pdev->dev, pe->table_group.tables[0]);
> 	/*
> 	 * Note: iommu_add_device() will fail here as
>-- 
>2.4.0.rc3.8.gfb3e7d5
>