From: Bjorn Helgaas <bhelgaas@google.com>
Date: Mon, 26 Oct 2015 03:43:22 +0000 (+0900)
Subject: PCI: Set SR-IOV NumVFs to zero after enumeration
X-Git-Tag: v4.1.12-92~237^2~1
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=82022e587c851d0dc8142fdaa3d34bd8a349f951;p=users%2Fjedix%2Flinux-maple.git

PCI: Set SR-IOV NumVFs to zero after enumeration

Orabug: 21547430

The enumeration path should leave NumVFs set to zero.  But after
4449f079722c ("PCI: Calculate maximum number of buses required for VFs"),
we call virtfn_max_buses() in the enumeration path, which changes NumVFs.
This NumVFs change is visible via lspci and sysfs until a driver enables
SR-IOV.

Set NumVFs to zero after virtfn_max_buses() computes the maximum number of
buses.

Fixes: 4449f079722c ("PCI: Calculate maximum number of buses required for VFs")
Based-on-patch-by: Ethan Zhao <ethan.zhao@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
---

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index ee0ebff103a4..3abe15e46dc6 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -384,7 +384,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
 	int rc;
 	int nres;
 	u32 pgsz;
-	u16 ctrl, total, offset, stride;
+	u16 ctrl, total;
 	struct pci_sriov *iov;
 	struct resource *res;
 	struct pci_dev *pdev;
@@ -414,11 +414,6 @@ static int sriov_init(struct pci_dev *dev, int pos)
 
 found:
 	pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
-	pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
-	pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
-	pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
-	if (!offset || (total > 1 && !stride))
-		return -EIO;
 
 	pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 	i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
@@ -456,8 +451,6 @@ found:
 	iov->nres = nres;
 	iov->ctrl = ctrl;
 	iov->total_VFs = total;
-	iov->offset = offset;
-	iov->stride = stride;
 	iov->pgsz = pgsz;
 	iov->self = dev;
 	pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
@@ -475,6 +468,11 @@ found:
 	dev->sriov = iov;
 	dev->is_physfn = 1;
 	iov->max_VF_buses = virtfn_max_buses(dev);
+	pci_iov_set_numvfs(dev, 0);
+	if (!iov->offset || (total > 1 && !iov->stride)) {
+		rc = -EIO;
+		goto failed;
+	}
 
 	return 0;
 
@@ -483,7 +481,7 @@ failed:
 		res = &dev->resource[i + PCI_IOV_RESOURCES];
 		res->flags = 0;
 	}
-
+	dev->sriov = NULL;
 	kfree(iov);
 	return rc;
 }