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

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 <redacted>
---
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);