From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:42785 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750843AbcB2SAW (ORCPT ); Mon, 29 Feb 2016 13:00:22 -0500 Date: Mon, 29 Feb 2016 12:00:18 -0600 From: Bjorn Helgaas To: kelly.zytaruk@amd.com Cc: Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI: Support SRIOV on Legacy EndPoint device Message-ID: <20160229180018.GA3653@localhost> References: <1455041338-3644-1-git-send-email-kelly.zytaruk@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1455041338-3644-1-git-send-email-kelly.zytaruk@amd.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Tue, Feb 09, 2016 at 01:08:58PM -0500, kelly.zytaruk@amd.com wrote: > From: Kelly Zytaruk > > 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 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 Signed-off-by: Bjorn Helgaas > --- > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html