PCI: Add pcibios_sriov_enable() and pcibios_sriov_disable()

VFs are dynamically created when a driver enables them.  On some platforms,
like PowerNV, special resources are necessary to enable VFs.

Add platform hooks for enabling and disabling VFs.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 5643a1011e23..64c46925c62d 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -220,6 +220,11 @@ static void virtfn_remove(struct pci_dev *dev, int id, int reset)
         pci_dev_put(dev);
 }
 
+int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
+{
+       return 0;
+}
+
 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 {
         int rc;
@@ -231,6 +236,7 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
         struct pci_sriov *iov = dev->sriov;
         int bars = 0;
         int bus;
+        int retval;
 
         if (!nr_virtfn)
                 return 0;
@@ -307,6 +313,12 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
         if (nr_virtfn < initial)
                 initial = nr_virtfn;
 
+        if ((retval = pcibios_sriov_enable(dev, initial))) {
+                dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n",
+                        retval);
+                return retval;
+        }
+
         for (i = 0; i < initial; i++) {
                 rc = virtfn_add(dev, i, 0);
                 if (rc)
@@ -335,6 +347,11 @@ failed:
         return rc;
 }
 
+int __weak pcibios_sriov_disable(struct pci_dev *pdev)
+{
+       return 0;
+}
+
 static void sriov_disable(struct pci_dev *dev)
 {
         int i;
@@ -346,6 +363,8 @@ static void sriov_disable(struct pci_dev *dev)
         for (i = 0; i < iov->num_VFs; i++)
                 virtfn_remove(dev, i, 0);
 
+        pcibios_sriov_disable(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);