[PATCH 1/2] PCI/IOV: provide flag to skip VF scanning

[Sebastian Ott]

Provide a flag to skip scanning for new VFs after SRIOV enablement.
This can be set by implementations for which the VFs are already
reported by other means.

Signed-off-by: Sebastian Ott <seb...@linux.ibm.com>
---
 drivers/pci/iov.c   | 48 ++++++++++++++++++++++++++++++++++++------------
 include/linux/pci.h |  1 +
 2 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 9616eca3182f..3aa115ed3a65 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -252,6 +252,27 @@ int __weak pcibios_sriov_disable(struct pci_dev *pdev)
        return 0;
 }
 
+static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
+{
+       unsigned int i;
+       int rc;
+
+       if (dev->no_vf_scan)
+               return 0;
+
+       for (i = 0; i < num_vfs; i++) {
+               rc = pci_iov_add_virtfn(dev, i);
+               if (rc)
+                       goto failed;
+       }
+       return 0;
+failed:
+       while (i--)
+               pci_iov_remove_virtfn(dev, i);
+
+       return rc;
+}
+
 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 {
        int rc;
@@ -337,21 +358,15 @@ static int sriov_enable(struct pci_dev *dev, int 
nr_virtfn)
        msleep(100);
        pci_cfg_access_unlock(dev);
 
-       for (i = 0; i < initial; i++) {
-               rc = pci_iov_add_virtfn(dev, i);
-               if (rc)
-                       goto failed;
-       }
+       rc = sriov_add_vfs(dev, initial);
+       if (rc)
+               goto err_pcibios;
 
        kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
        iov->num_VFs = nr_virtfn;
 
        return 0;
 
-failed:
-       while (i--)
-               pci_iov_remove_virtfn(dev, i);
-
 err_pcibios:
        iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
        pci_cfg_access_lock(dev);
@@ -368,17 +383,26 @@ static int sriov_enable(struct pci_dev *dev, int 
nr_virtfn)
        return rc;
 }
 
-static void sriov_disable(struct pci_dev *dev)
+static void sriov_del_vfs(struct pci_dev *dev)
 {
-       int i;
        struct pci_sriov *iov = dev->sriov;
+       int i;
 
-       if (!iov->num_VFs)
+       if (dev->no_vf_scan)
                return;
 
        for (i = 0; i < iov->num_VFs; i++)
                pci_iov_remove_virtfn(dev, i);
+}
+
+static void sriov_disable(struct pci_dev *dev)
+{
+       struct pci_sriov *iov = dev->sriov;
+
+       if (!iov->num_VFs)
+               return;
 
+       sriov_del_vfs(dev);
        iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
        pci_cfg_access_lock(dev);
        pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 11c71c4ecf75..f70b9ccd3e86 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -405,6 +405,7 @@ struct pci_dev {
        unsigned int    non_compliant_bars:1;   /* Broken BARs; ignore them */
        unsigned int    is_probed:1;            /* Device probing in progress */
        unsigned int    link_active_reporting:1;/* Device capable of reporting 
link active */
+       unsigned int    no_vf_scan:1;           /* Don't scan for VF's after VF 
enablement */
        pci_dev_flags_t dev_flags;
        atomic_t        enable_cnt;     /* pci_enable_device has been called */
 
-- 
2.13.4