[RFC PATCH V3 04/17] PCI: SRIOV: add VF enable/disable hook

[Wei Yang <weiyang@linux.vnet.ibm.com>]

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

This patch adds two hooks for platform initialization before creating the VFs.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
---
 drivers/pci/iov.c |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 1d21f43..cc87773 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -250,6 +250,11 @@ static void sriov_disable_migration(struct pci_dev *dev)
 	iounmap(iov->mstate);
 }
 
+int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 vf_num)
+{
+       return 0;
+}
+
 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 {
 	int rc;
@@ -260,6 +265,7 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	struct pci_dev *pdev;
 	struct pci_sriov *iov = dev->sriov;
 	int bars = 0;
+	int retval;
 
 	if (!nr_virtfn)
 		return 0;
@@ -334,6 +340,12 @@ 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_setup()\n",
+				retval);
+		return retval;
+	}
+
 	for (i = 0; i < initial; i++) {
 		rc = virtfn_add(dev, i, 0);
 		if (rc)
@@ -368,6 +380,11 @@ failed:
 	return rc;
 }
 
+int __weak pcibios_sriov_disable(struct pci_dev *pdev)
+{
+       return 0;
+}
+
 static void sriov_disable(struct pci_dev *dev)
 {
 	int i;
@@ -382,6 +399,8 @@ 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);
-- 
1.7.9.5