On Mon, Apr 10, 2017 at 07:58:13PM +0800, Yongji Xie wrote:
> This overrides pcibios_default_alignment() to set default alignment
> to PAGE_SIZE for all PCI devices on PowerNV platform. Thus sub-page
> BARs would not share a page and could be mapped into guest when VFIO
> passthrough them.
Thanks for doing this. This looks like a reasonable strategy to me,
but it would be good to get a powerpc ack for it.
> Signed-off-by: Yongji Xie <elohimes@xxxxxxxxx>
> ---
> arch/powerpc/include/asm/machdep.h | 2 ++
> arch/powerpc/kernel/pci-common.c | 8 ++++++++
> arch/powerpc/platforms/powernv/pci-ioda.c | 7 +++++++
> 3 files changed, 17 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
> index 5011b69..a82c192 100644
> --- a/arch/powerpc/include/asm/machdep.h
> +++ b/arch/powerpc/include/asm/machdep.h
> @@ -173,6 +173,8 @@ struct machdep_calls {
> /* Called after scan and before resource survey */
> void (*pcibios_fixup_phb)(struct pci_controller *hose);
>
> + resource_size_t (*pcibios_default_alignment)(struct pci_dev *);
> +
> #ifdef CONFIG_PCI_IOV
> void (*pcibios_fixup_sriov)(struct pci_dev *pdev);
> resource_size_t (*pcibios_iov_resource_alignment)(struct pci_dev *, int resno);
> diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> index ffda24a..ceda574 100644
> --- a/arch/powerpc/kernel/pci-common.c
> +++ b/arch/powerpc/kernel/pci-common.c
> @@ -233,6 +233,14 @@ void pcibios_reset_secondary_bus(struct pci_dev *dev)
> pci_reset_secondary_bus(dev);
> }
>
> +resource_size_t pcibios_default_alignment(struct pci_dev *pdev)
> +{
> + if (ppc_md.pcibios_default_alignment)
> + return ppc_md.pcibios_default_alignment(pdev);
> +
> + return 0;
> +}
> +
> #ifdef CONFIG_PCI_IOV
> resource_size_t pcibios_iov_resource_alignment(struct pci_dev *pdev, int resno)
> {
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index e367382..354c852 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -3297,6 +3297,11 @@ static void pnv_pci_setup_bridge(struct pci_bus *bus, unsigned long type)
> }
> }
>
> +static resource_size_t pnv_pci_default_alignment(struct pci_dev *pdev)
> +{
> + return PAGE_SIZE;
> +}
> +
> #ifdef CONFIG_PCI_IOV
> static resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
> int resno)
> @@ -3830,6 +3835,8 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
> hose->controller_ops = pnv_pci_ioda_controller_ops;
> }
>
> + ppc_md.pcibios_default_alignment = pnv_pci_default_alignment;
> +
> #ifdef CONFIG_PCI_IOV
> ppc_md.pcibios_fixup_sriov = pnv_pci_ioda_fixup_iov_resources;
> ppc_md.pcibios_iov_resource_alignment = pnv_pci_iov_resource_alignment;
> --
> 1.7.9.5
>
