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    SubjectRe: [PATCH] PCI: Support SRIOV on Legacy EndPoint device
    On Tue, Feb 09, 2016 at 01:08:58PM -0500, kelly.zytaruk@amd.com wrote:
    > From: Kelly Zytaruk <kelly.zytaruk@amd.com>
    >
    > It is not neccessary to check for PCI_EXP_TYPE in sriov_init(). There appears to be no reason for the check.
    >
    > Some AMD GPUs have hardware support for grapics SRIOV.
    > If the GPU has a display output then the GPU needs to support Legacy VGA operation.
    > If CLASS_CODE = VGA then the device should have a Port Type = Legacy EndPoint.
    > Therefore in order to enable SRIOV on a GPU with a display output, LEGACY_END_POINT is supported as a valid Port Type by removing the check for Port Type.
    >
    > Patch is also logged in Bugzilla #112221
    >
    > Signed-off-by: Kelly Zytaruk <kelly.zytaruk@amd.com>

    Applied to pci/virtualization for v4.6, with changelog as follows:

    PCI: Support SR-IOV on any function type

    Previously, we only supported SR-IOV on PCI Express Endpoints and Root
    Complex Integrated Endpoints. This restriction has been present since
    d1b054da8f59 ("PCI: initialize and release SR-IOV capability") added SR-IOV
    support, but the spec does not require it. In fact, the SR-IOV spec r1.1,
    sec 3.3, says the SR-IOV extended capability may be present for any Type 0
    function.

    Remove the function type test, so we can support SR-IOV on any function.

    Some AMD GPUs have display outputs, use the VGA class code, are Legacy
    Endpoints, and support SR-IOV. This change allows Linux to enable SR-IOV
    on these devices.

    [bhelgaas: changelog]
    Link: https://bugzilla.kernel.org/show_bug.cgi?id=112221
    Signed-off-by: Kelly Zytaruk <kelly.zytaruk@amd.com>
    Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

    > ---
    > drivers/pci/iov.c | 4 ----
    > 1 file changed, 4 deletions(-)
    >
    > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
    > index 31f31d4..fe4bd0a 100644
    > --- a/drivers/pci/iov.c
    > +++ b/drivers/pci/iov.c
    > @@ -387,10 +387,6 @@ static int sriov_init(struct pci_dev *dev, int pos)
    > struct resource *res;
    > struct pci_dev *pdev;
    >
    > - if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
    > - pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
    > - return -ENODEV;
    > -
    > pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
    > if (ctrl & PCI_SRIOV_CTRL_VFE) {
    > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
    > --
    > 1.7.10.4
    >
    > --
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