pds_core: add initial VF device handling

This is the initial VF PCI driver framework for the new
pds_vdpa VF device, which will work in conjunction with an
auxiliary_bus client of the pds_core driver. This does the
very basics of registering for the new VF device, setting
up debugfs entries, and registering with devlink.

Signed-off-by: Shannon Nelson <[e-mail]>
Acked-by: Jakub Kicinski <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/amd/pds_core/core.h

···
 	int res_index;
 };
 
+struct pdsc_vf {
+	struct pds_auxiliary_dev *padev;
+	u16     index;
+	__le16  vif_types[PDS_DEV_TYPE_MAX];
+};
+
 struct pdsc_devinfo {
 	u8 asic_type;
 	u8 asic_rev;
···
 	struct dentry *dentry;
 	struct device *dev;
 	struct pdsc_dev_bar bars[PDS_CORE_BARS_MAX];
+	struct pdsc_vf *vfs;
+	int num_vfs;
+	int vf_id;
 	int hw_index;
 	int uid;
 

drivers/net/ethernet/amd/pds_core/main.c

···
 /* Supported devices */
 static const struct pci_device_id pdsc_id_table[] = {
 	{ PCI_VDEVICE(PENSANDO, PCI_DEVICE_ID_PENSANDO_CORE_PF) },
+	{ PCI_VDEVICE(PENSANDO, PCI_DEVICE_ID_PENSANDO_VDPA_VF) },
 	{ 0, }	/* end of table */
 };
 MODULE_DEVICE_TABLE(pci, pdsc_id_table);
···
 			       (u64)page_num << PAGE_SHIFT, PAGE_SIZE);
 }
 
+static int pdsc_sriov_configure(struct pci_dev *pdev, int num_vfs)
+{
+	struct pdsc *pdsc = pci_get_drvdata(pdev);
+	struct device *dev = pdsc->dev;
+	int ret = 0;
+
+	if (num_vfs > 0) {
+		pdsc->vfs = kcalloc(num_vfs, sizeof(struct pdsc_vf),
+				    GFP_KERNEL);
+		if (!pdsc->vfs)
+			return -ENOMEM;
+		pdsc->num_vfs = num_vfs;
+
+		ret = pci_enable_sriov(pdev, num_vfs);
+		if (ret) {
+			dev_err(dev, "Cannot enable SRIOV: %pe\n",
+				ERR_PTR(ret));
+			goto no_vfs;
+		}
+
+		return num_vfs;
+	}
+
+no_vfs:
+	pci_disable_sriov(pdev);
+
+	kfree(pdsc->vfs);
+	pdsc->vfs = NULL;
+	pdsc->num_vfs = 0;
+
+	return ret;
+}
+
 static int pdsc_init_vf(struct pdsc *vf)
 {
-	return -1;
+	struct devlink *dl;
+
+	vf->vf_id = pci_iov_vf_id(vf->pdev);
+
+	dl = priv_to_devlink(vf);
+	devl_lock(dl);
+	devl_register(dl);
+	devl_unlock(dl);
+
+	return 0;
 }
 
 static const struct devlink_health_reporter_ops pdsc_fw_reporter_ops = {
···
 	devl_unlock(dl);
 
 	if (!pdev->is_virtfn) {
+		pdsc_sriov_configure(pdev, 0);
+
 		del_timer_sync(&pdsc->wdtimer);
 		if (pdsc->wq)
 			destroy_workqueue(pdsc->wq);
···
 	.id_table = pdsc_id_table,
 	.probe = pdsc_probe,
 	.remove = pdsc_remove,
+	.sriov_configure = pdsc_sriov_configure,
 };
 
 static int __init pdsc_init_module(void)